Performance Analysis of a Dual-Battery Scheme for Energy Efficiency in Wireless Mobile Term

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双离子电池工作原理

双离子电池工作原理A dual-ion battery is a type of rechargeable battery that utilizes both cations and anions as charge carriers in its electrodes. These batteries operate through a process of ion exchange between thetwo electrodes, which are typically made of different materials. When an external circuit is connected to the battery, ions flow between the electrodes, creating an electrical current that can power various devices.双离子电池是一种可充电电池，它利用阴离子和阳离子作为电极中的电荷载体。

这种电池通过两个电极之间的离子交换过程来工作，这两个电极通常由不同材料制成。

当外部电路连接到电池时，离子在电极之间流动，产生电流，可以为各种设备供电。

One of the key advantages of dual-ion batteries is their high energy density, which allows them to store a large amount of energy in a relatively small and lightweight package. This makes them ideal for use in portable electronic devices, such as smartphones and laptops, where space and weight are at a premium. Additionally, dual-ion batteries have a long cycle life, meaning they can be recharged anddischarged thousands of times without significant degradation in performance.双离子电池的一大优势是其高能量密度，这使得它们可以在相对较小和轻便的包装中存储大量能量。

2022肿瘤相关性肌肉减少症临床诊断与治疗指南(最全版)

2022肿瘤相关性肌肉减少症临床诊断与治疗指南(最全版)摘要：肌肉减少症是一种以进行性、广泛性的骨骼肌含量减少和功能减退为主要特点的综合征。

由于肿瘤患者的高分解代谢和低合成代谢状态，因此,肌肉减少症的发生率较高。

与恶倒中瘤相关的肌肉减少症，称为肿瘤相关性肌肉减少症，不仅影响患者机体成分的正常代谢，还会降低患者治疗疗效、生活质量，缩短生存期。

因此，做好肿瘤患者的营养筛查和评估，及时发现肿瘤相关性肌肉减少症，并给予有效干预，对于患者的长期生存具有深远意义。

基于此，中国抗癌协会肿瘤营养专业委员会组织专家制订了本共识，主要根据我国肿瘤相关性肌肉减少症诊疗现状、国内外发表的循证医学证据，结合临床、药学、营养、护理等领域的专家经验和意见，采用欧洲心脏学会证据分级和推荐强度标准,围绕肿瘤相关肌肉减少症的筛查、诊断、评估、治疗等方面进行分析、讨论与总结。

最终，制订了肿瘤相关性肌肉减少症临床诊断与治疗指南，为临床医师规范化和标准化诊疗提供参考依据。

关键词：肿瘤;肌肉减少症;诊断治疗;指南肌肉减少症(sarcopenia)是一种以进行性、广泛性的骨骼肌含量减少和功能减退为主要特点的综合征⑴。

临床上主要表现为机体活动功能障碍，继而增加跌倒、骨折及死亡风险⑵。

肌肉减少症在老年人群中发生率高。

据统计，肌肉减少症的患病率在60〜7。

岁老人中为5%~13%,在80岁以上的老人中为11%~50%【3】。

重要的是，肿瘤患者因高分解代谢和低合成代谢状态，肌肉减少症发生率也较高。

此种与肿瘤相关的肌肉减少症，称为肿瘤相关性肌肉减少症(cancer-related sarcopenia),其患病率因肿瘤类型、分期、测量方法不同而异。

一项研究表明，在65岁以上老年人群中，胃癌合并肌肉减少症发病率高达28.8%⑷，远高于肌肉减少症的人群发病率。

肿瘤相关性肌肉减少症不仅影响患者机体成分的正常代谢，与术后并发症，尤其是严重并发症相关，还会降低抗肿瘤药物的疗效，增加不良反应，降低患者生活质量，缩短生存期【5,6,乙8,9］。

buckboost双向变换器研究

Buck-Boost双向变换器研究Abstract：In the paper, research on a soft-switching bi-directional buck-boost converter is presented. The converter has 5 different operation modes when inductor current is different. The operation of three modes under the conditions that inductor current passes through zero is detailed. Analysis results reveal that under these three operation modes, the zero-voltage-switching of MOSFETs can be obtained, and the MOSFET body diodes can also be turned on and off naturally without reverse recovery problem. Finally a design example of a 48V/24V bi-directional buck-boost converter is presented. The appropriate choice of control loop parameters can make the converter stable at buck and boost operation modes respectively, and it testifies that the proposed soft-switching bi-directional buck-boost converter ispractical and feasible.Keyword：Converter; Bi-directional; Buck-Boost; Zero-voltage-switching1引言双向DC/DC变换器具有双向能量流能力，广泛应用于多电飞机高压直流配电系统[1]、蓄电池充/放电系统[2] [3]、UPS系统[4]、太阳能发电系统[5]，因此对双向DC/DC变换器的研究也越来越广泛和深入。

罗德与施瓦茨 SA2600 手持式实时频谱分析仪说明书

SA2600Real-Time SpectrumAnalyzerThe SA2600handheld real-time spectrum analyzer is ideal for a wide variety of applications,ranging from small radio repair depots,to spectral interference management in the field.Featuring true real-time DPX™capability in a handheld spectrum analyzer,the SA2600offers practical solutions to discover short transient spectral events that slip past conventional spectrum and batch processing vector signal analyzers.The portability allows easy instrument sharing in the laboratory environment and robust all-day battery operation in the field,all with the largest display in its class.With field-ready,rugged hardware featuring outstanding displayed average noise level (DANL),spurious free dynamic range (SFDR),phase noise and easy LAN networking capability in a portable unit,the SA2600is a great choice for general purpose spectrum measurements.Handheld Real-Time spectrum analyzer with DPX™technologyproviding live RF view of the spectrumI100%POI for transients with a minimum duration of 500microsecondsI Rapid in-field detection and location of elusive and intermittent signals IRugged handheld platform optimized for field useFeatures &BenefitsDatasheet |/SA2600I D i s c o v e rIRevolutionary DPX™ spectrum processing provides intuitive understanding of live RF signals using colors based on frequency of occurrence, displaying 2,500 spectrums per sec with a 100% POI for transients with a minimum duration of 500 microseconds IInput Frequency Range 10kHz-6.2GHz to cover most modern signal sources IUnsurpassed ability to detect very low level signals with -153dBm DANL at 10 Hz RBWI L o c a t eIFind outdoor signals by plotting measurements directly onto GPS-integrated maps IFind in-building signals with a Tap-and-Walk-and-Tap interface using mapsIIntegrated mapping solution allows on-site analysis of difficult problemsI R e a d y f o r t h e F i e l dIBenchtop spectrum analyzer performance in a ruggedized handheld battery-operated field unit IIntuitive Windows CE-based touch screen intuitive interface designed for field conditions I Backlit display, viewable in direct sunlight IExtended battery performance with hot-swappable dual batteries2The SA2600 has a variety of unique features such as visual and audio signal strength indicators and integrated GPS measurements’ mapping with direction-findingvectors for easy location of signal emitters. Having 100%probability of intercept for signals of 500 microseconds or greater, and crystal-clear spectrograms, the SA2600 is an ideal tool for surveying the RF spectrum, mappingreceived signal strength and resolving spectral interference disputes.It is perfect for engineers doing pre-deployment analyses, signal strength mapping or troubleshooting interference, as well as regulatory agencies who need portable measurement capabilities suitable for today’s RF systems.The SA2600 is designed for general purpose field use in a wide range of frequency bands and modulation types. It incorporates a unique touch-screen interface that allows very fast tuning and zooming in and out on signals, improving operator efficiency when working across a wide range of frequency bands. The SA2600 offers both performance handheld spectrum analysis as well as innovative must-have technologies like DPX™ and GPS mapping at an affordable price.Datasheet | SA2600 Real-Time Spectrum AnalyzerTektronix SA2600 Real-Time Spectrum Analyzer3DiscoverThe patented DPX™ spectrum display offers an intuitive live color view of signal transients changing over time in the frequency domain, giving you immediate confidence in the stability of your design or instantly displaying a fault when it occurs. The Live RF spectrum processing engine brings real time analysis of transient events to spectrum analyzers. Performing 2,500 spectrum updates persecond, transients as brief as 500 µs can be displayed in the frequency domain. This offers tremendousimprovement over swept analysis techniques. Events are color-coded by rate of occurrence onto a bitmappeddisplay, providing unparalleled insight into the behavior ofintermittent signals.Figure 1. DPX showing three hopping frequencies/SA2600Figure 2. Trace math showing signals not presentin the referenceScanning the RF spectrum allows users to spot which signal emitters are in the area. New signals with significant power are usually candidates for further analysis. However, weak signals can also be of interest, especially when they are close to strong signals. Of particular interest are signals that are present in the spectrum today but were not there yesterday. Signals can be stored as reference and deviations from this reference can be quickly identified using the trace math feature. The SA2600 makes analysis easier by quickly logging signals that are weak, bursty, hopping, timemultiplexed, or intentionally random. It takes advantage of the FFT -based spectrum analysis capability to allow users to see the true shape of the signal, even when it is bursty.Masks can be automatically created from traces captured earlier. You can compare this mask to the current trace and if a mask violation occurs, the trace is logged. Finally,when the spectrogram is paused, you can scroll through the spectrogram’s time-axis and view the results.4Datasheet | SA2600 Real-Time Spectrum AnalyzerLocateOnce a signal of interest is identified, the SA2600 provides various field-proven signal-hunting tools to locate it. For the easier-to-find signals, the signal strength meterproduces audible tones that vary in pitch as a function of the received power. The user can simply point the antenna in the direction that receives maximum power. This allows them to look for signals while watching their surroundings,not the screen.Harder to find signals, such as those influenced by multipath, fading or low signal strength, the SA2600provides several signal-mapping tools to facilitate hunting for these signals. Maps can be imported from a variety of formats using the PC-based iMap Converter application.Signal intensity can be directly recorded, and direction-finding arrows can be directly placed on the map by the user to show the directions where the signal intensity is the greatest. Once you are done, you have a record ofyour work.Figure 4. Color-coded measurementsfor rapid in-field analysisFigure 3. Signal strength for accurate signal finding5Analyzing mapped signals is a quick way to locate signals that can be difficult to find otherwise. Traces can be recorded on a map either manually or automatically. Built-in GPS can be used to record signal position and time data as the instrument moves.The mapping functionality works indoors as well. Using the unique “tap-and-walk-and-tap” interface, users tap on the map to indicate a start location for data acquisition. The end location is similarly recorded. The SA2600 captures the data with the initial tap and follows a straight-line to the end tap. It then displays the measurements, equally spaced between these two measurement points.Figure 5. Locating Interference withintegrated mapping solutionFigure 6. Mapping signals IndoorsReady for the fieldThe SA2600 will quickly scan the RF environment and help you locate the interference sources with its field-proven signal hunting tools. The instrument’s layout is designed in a way that helps reduce the possibility of user mistakes even if the issue is complex. The instrument does not get in your way. The Windows CE-based touch screeninterface is designed specifically to enhance productivity and navigation. While other solutions sometimes require offline GPS and mapping software, the SA2600 includes integrated GPS and mapping tools to allow more efficient interference location capability. The extremely rugged,rubberized magnesium alloy case is designed for harsh field environments and can withstand drops and mistreatment. With the optional second battery, the SA2600 provides more than five hours of use forcontinuous Spectrum Mode. The hot-swappable batteries can dramatically extend the in-field usage time because they can be replaced one at a time./SA26006Datasheet | SA2600 Real-Time Spectrum Analyzer26007/SA2600G e n e r a l P u r p o s e R F M e a s u r e m e n t s C h a r a c t e r i s ti c sD P X ™ M e a s u r e m e n t s P r o c es s i n g C h a ra c t e r i s t i c sDatasheet | SA2600 Real-Time Spectrum AnalyzerM a p p i n gB a t t e r y L i f e8E n v i r o n m e n ta l c h a r a c t e r i s t i c sM i s c e l l a n e o u s c h a r a c t e r i s t i c sS a f e t y c o m p l i a n c eD i s p l a y c h a r a c t e r i s t i c s/SA26009Contact Tektronix:Please visit /communications Phone:1-800-833-9200 option 1+1-469-330-4000Locate your nearest Tektronix representative at:/contactusCopyright © Tektronix. All rights reserved. Tektronix products are covered by U.S. and foreign patents, issued and pend-ing. Information in this publication supersedes that in all previously published material. Specification and price change privileges reserved. TEKTRONIX and TEK are registered trademarks of Tektronix, Inc. All other trade names referenced are the service marks, trademarks or registered trademarks of their respective companies.06/08 | CWW-22258-0For Further Information:Tektronix maintains a comprehensive, constantly expanding collection of application notes, technical briefs and other resources to help engineers working on the cutting edge of technology.Please visit /communicationsAbout Tektronix:Tektronix has more than 60 years of experience in providing network operators and equipment manufacturers a comprehensive andunparalleled suite of network diagnostics and management solutions for fixed, mobile, IP and converged multi-service networks.These solutions support architectures and applications such as fixed mobile convergence, IMS, broadband wireless access, WiMAX, VoIP and triple play, including IPTV .Learn more about Tektronix' communications test, measurement and network monitoring solutions by visiting:/communicationsDatasheet | SA2600 Real-Time Spectrum Analyzer。

燃油车和电动车的差异英语作文

燃油车和电动车的差异英语作文The difference between fuel vehicles and electric vehiclesIn recent years, there has been a great controversy about the choice of fuel vehicles and electric vehicles in China, coupled with the skyrocketing international oil prices, car selection has once again become a hot topic for our people.There are great differences between fuel vehicles and electric vehicles, and their differences are mainly reflected in the following aspects:Fuel vehicles use engines and gearboxes, fuel vehicles as an old brand of power equipment, its performance and stability is strong; electric vehicles have no gearbox and use electric motors, the center of gravity of electric vehicles is very low, because the battery pack of electric vehicles is installed on the chassis, and the volume and weight of the motor are also very small.The four-wheel drive system of fuel-fueled vehicles is different from that of electric vehicles, and the four-wheel drive system of electric vehicles with dual motors is better than that of gasoline vehicles.The power output characteristics of the gasoline engine of the fuel vehicle are different from those of the electric vehicle: the gasoline engine of the fuel vehicle needs to reach a certain speed to output the maximum torque, while the motor of the electric vehicle does not need to start the car. Press the accelerator pedal to the end, the motor can immediately output the maximum torque, which is also the reason why many high-performance electric vehicles accelerate very fast.The interior stillness of the fuel vehicle is not as good as that of the electric car: the gasoline engine of the fuel vehicle will have noiseand jitter when it is running; the interior stillness of the electric car is better when the electric vehicle is running, and the motor will not produce excess noise and jitter when the motor is running.The mileage of fuel vehicles is better than that of electric vehicles: the range of electric vehicles will also be affected when they use air conditioning in summer and winter, and the battery performance of electric vehicles will also be affected when the outdoor temperature is relatively low in winter. therefore, due to the relationship between overweight and battery life, the high-speed cruising ability of most electric vehicles is worse than that of fuel vehicles.Fuel vehicle has a long history, after years of running-in and improvement, almost make up for all its disadvantages, for users, its recognition is higher, more familiar with its function; electric vehicle as a new energy power equipment, the precipitation of time is less, and its perfection needs to be verified.Fuel vehicles are still the mainstream power equipment in the market, and their power has more advantages than other energy sources, especially high-power vehicles, which have higher power supply and can easily climb steep slopes and drive on roads with poor road conditions. there are no major problems in the operation of conventional sections of electric vehicles, but the performance of electric vehicles is worrying when they encounter irregular sections and slope climbing.The crude oil mining of fuel vehicles does great damage to the environment, the smell of gasoline is not accepted by many people, and the exhaust gas is more polluting to the environment, and it is difficult to refuel in remote areas; compared with fuel vehicles, electric vehicles consume less energy and are more convenient. Spare batteries, electric boxes and solar panels can be used to solve the energy problem in today's era of widespread electricity.To sum up, as people's means of transportation, fuel vehicles and electric cars have their own advantages and disadvantages. Each of us can choose the car that suits us according to our own preferences and needs.。

生物反馈治疗仪说明书

MYOTRAC INFINITIDual SEMGThe Manufacturer: Thought Technology Ltd.2180 Belgrave AvenueMontreal, Quebec, CanadaH4A 2L8Product Name: MyoTrac Infiniti System Product #: T9800Device Name: MyoTrac Infiniti Encoder Device #: SA9800•Type BF Equipment •Internally powered equipment•Continuous operation•Read Instruction Manual•The pins of the connectors identified with the ESD warning symbol should not be touched unless ESB precautionary procedures are used.CAUTION•US Federal Law restricts this device to sale by, or on order of, a physician or any otherpractitioner licensed by the law of the state in which he or she practices to use or order theuse of this device.WARNING•Do not operate Active Sensors within 10 feet of an operating cellular phone, similar radio transmitting device, other powerful radio interference producing sources such as arcwelders, radio thermal treatment equipment, x-ray machines, or any other equipment thatproduces electrical sparks. Portable and mobile RF communication equipment can affectthis equipment.•With the MyoTrac Infiniti Encoder SA9800 use only with supplied power supply. GlobTek Part Number WR92B2500LF9P-Y-MED (WR95/WR93/WR97) or GS889•The PC used with MyoTrac Infiniti must be placed outside the patient/client environment(more than 3 meters or 10 feet) or the PC must comply with EN60601-1 (system safety).•After use, the Batteries or the Battery pack must be disposed of in accordance with local, state and federal regulations and laws.•After use, the Disposable Electrodes may be a biohazard. Handle, and when applicable, dispose of these materials in accordance with accepted medical practice and any applicablelocal, state and federal laws and regulations.•Reusable electrodes present a potential risk of cross-infection especially when used onabraded skin, unless they are restricted to a single patient or sterilized between patients. Ifsterilizing electrodes, employ only gas sterilization.•Radiated radio frequency electromagnetic fields can cause performance degradation in the MyoScan-Pro EMG sensor. In the worst case, an RF field strength of 22mV/M can causean increase of 1μV in the signal reading from a MyoScan-Pro sensor. Be sure to keep inmind that a very relaxed muscle should provide an EMG reading of approximately 1-3μV.•This device is capable of generating current densities exceeding 2mA r.m.s./cm² this may require special attention of the operator.•Avoid accidental contact between connected but unused applied parts and other conductive parts including those connected to protective earth.•Explosion Hazard; Do not use in the presence of a flammable anesthetic mixture with air, or with Oxygen or Nitrous Oxide.•Not to be immersed in water.•Take care in arranging patient and sensor cables to avoid risk of patient entanglement or strangulation.•The operator is responsible for ensuring the safety of any devices controlled or triggered by Infiniti equipment or software, or by any software or hardware receiving data from Infinitiequipment. Infiniti equipment must not be configured or connected in such a way thatfailure in its data acquisition, processing or control functions can trigger patient feedbackstimulus that poses an unacceptable level of risk.•Use of any equipment in a biofeedback or stimulation context should be immediatelyterminated upon any sign of treatment-related distress or discomfort.•Not to be connected to a patient undergoing MRI, Electro surgery or defibrillation.•Not for use with patients with undiagnosed pain conditions.•Only use the unit for which it was prescribed.•Do not immerse the unit in water or any other liquid substance.•Do not use if you have symptoms of bladder infection.•Do not use with diminished mental capacity or physical competence limiting the use of the device.•Caution should be used for patients with suspected or diagnosed heart problems.•Caution should be used for patients with suspected or diagnosed epilepsy.•Electrode placement and stimulation settings should be based on the guidance of theprescribing practitioner.•If damage is evident of the unit or accessories, discontinue use and contact your supplierfor further information on repair.•The system should not be used adjacent to or stacked with other equipment, if usedadjacent or stacked the unit should be observed to verify normal operation in theconfiguration in which it will be used.•Use of accessories, transducers or cables other than those specified by ThoughtTechnology ltd may result in increased emissions or decreased immunity of the equipmentto electromagnetic energy.ATTENTION•Sensors and equipment damaged by static electricity are not covered under warranty. Toprevent static discharge from damaging the sensor and/or encoders, use anti-static mats orsprays in your working area. A humidifier may also be used to prevent static environmentsby conditioning hot, dry air. It is recommended that all staff involved with the unit receive anexplanation of the ESD symbol and the precautions described above as a minimum.•Do not apply any electrode gel or equivalent directly on the sensor snaps. Always useelectrodes as a medium between the sensor and the client.•Not for diagnostic purposes, not defibrillator proof, not for critical patient monitoring.•To prevent voiding warranty by breaking connector pins, carefully align white guiding dot onsensor plug with slot on sensor input.•Make sure to remove electrodes from sensor snaps immediately after use.•Do not plug third party sensors directly into instrument inputs. Plug only ThoughtTechnology Active Sensor cable connectors into instrument inputs. All electrodes and thirdparty sensors must be connected to active sensors, either directly or through an adapter.•Remove batteries when the device is not being used for an extended period of time. Pleasedispose of battery following local regulations.INTENDED PURPOSE•Biofeedback, Relaxation & Muscle Re-Education purposes•Relaxation of muscle spasms•Prevention or retardation of disuse atrophy•Increasing local blood circulation•Muscle re-education•Maintaining or increasing range of motionNOTE•No preventative inspections required; maintenance must be performed by qualified personnel.Factory re-calibration can be requested.•The supplier will make available, upon request, circuit diagrams, component parts lists anddescription or other information required for the repair of product by qualified personnel.•The operator must be familiar with typical characteristics of signals acquired by thisequipment, and be able to detect anomalies in the acquired signal that could interfere withtreatment effectiveness. Depending on the importance of signal integrity, it may be advisableto continuously monitor the raw signals, in time and/or frequency domain, while the device isbeing used for biofeedback or other purposes. If anomalies are observed on acquired signals,and if you suspect a problem with electromagnetic interference, contact Thought Technologyfor a technical note on identification and remediation.•This product conforms to standards EN60601-1, EN60601-2-10 and EN60601-2-40; someencoder labeling may indicate superceded standards.MAINTENANCE AND CALIBRATION•Wipe encoder with a clean cloth•Factory testing and calibration ensure equipment accuracy and frequency response. Contact Thought Technology for factory re-calibration if necessary.STORAGE•Store in its original case at up to 90% humidity / 30C°TRANSPORTATION•Transport in its original caseManual # SA9814 Rev 4Guidance and manufacturer’s declaration – electromagnetic immunity The MyoTrac Infiniti is intended for use in the electromagnetic environment specified below. The customer or the user of the MyoTrac Infiniti should assure that it is used in such an environment, and that precautions regarding that environment are heeded.Immunity test IEC 60601test level Compliance level Electromagnetic environment –guidanceElectrostatic discharge (ESD) IEC 61000-4-2 ±6 kV contact±8 kV air±6 kV contact±8 kV airFloors should be wood, concrete orceramic tile. If floors are covered withsynthetic material, the relative humidityshould be at least 30 %.Electrical fast transient/burst IEC 61000-4-4 ±2 kV for powersupply lines±1 kV for input/outputlines±2 kV for powersupply lines±1 kV for input/outputlinesMains power quality should be that of atypical commercial or hospitalenvironment.SurgeIEC 61000-4-5 ±1 kV differentialmode±2 kV common mode±1 kV differentialmode±2 kV common modeMains power quality should be that of atypical commercial or hospitalenvironment.Voltage dips, short interruptions and voltage variations on power supply input linesIEC 61000-4-11 <5 % U T(>95 % dip in U T)for 0,5 cycle40 % U T(60 % dip in U T)for 5 cycles70 % U T(30 % dip in U T)for 25 cycles<5 % U T(>95 % dip in U T)for 5 sec<5 % U T(>95 % dip in U T)for 0,5 cycle40 % U T(60 % dip in U T)for 5 cycles70 % U T(30 % dip in U T)for 25 cycles<5 % U T(>95 % dip in U T)for 5 secMains power quality should be that of atypical commercial or hospitalenvironment. If the user of theMyoTrac Infiniti requirescontinued operation during powermains interruptions, it is recommendedthat the MyoTrac Infiniti bepowered from an uninterruptible powersupply or a battery.Power frequency (50/60 Hz) magnetic field IEC 61000-4-8 3 A/m 3 A/m Power frequency magnetic fieldsshould be at levels characteristic of atypical location in a typical commercialor hospital environment.NOTE U T is the a.c. mains voltage prior to application of the test level.NOTE 1 At 80 MHz and 800 MHz, the higher frequency range applies.NOTE 2 These guidelines may not apply in all situations. Electromagnetic propagation is affected by absorption Field strengths from fixed transmitters, such as base stations for radio (cellular/cordless) telephones and land mobile radios, amateur radio, AM and FM radio broadcast and TV broadcast cannot be predicted theoretically with accuracy. To assess the electromagnetic environment due to fixed RF transmitters, an electromagnetic site survey should be considered. If the measured field strength in the location in which the MyoTrac Infiniti is used exceeds the applicable RF compliance level above, the MyoTrac Infiniti should be observed to verify normal operation. If abnormal performance is observed, additional measures may be necessary, such as reorienting or relocating the MyoTrac Infiniti.Over the frequency range 150 kHz to 80 MHz, field strengths should be less than [V1] V/m.Guidance and manufacturer’s declaration – electromagnetic emissionsThe MyoTrac Infiniti is intended for use in the electromagnetic environment specified below. The customer or the user of the MyoTrac Infiniti should assure that it is used in such an environment.Emissions test Compliance Electromagnetic environment – guidanceRF emissions CISPR 11 Group 1 The MyoTrac Infiniti uses RF energy only for its internal function.Therefore, its RF emissions are very low and are not likely tocause any interference in nearby electronic equipment.RF emissionsCISPR 11Class BHarmonic emissionsIEC 61000-3-2Not applicableVoltage fluctuations/ flicker emissions IEC 61000-3-3 Not applicableThe MyoTrac Infiniti is suitable for use in all establishments,including domestic establishments and those directly connected tothe public low-voltage power supply network that suppliesbuildings used for domestic purposes.Table of ContentsAbout This Guide (9)Chapter 1 (10)Introduction to your MYOTRAC INFINITI™ Dual SEMG Encoder (10)System Requirements (11)MyoTrac Infiniti Components (12)Connection to the Client (15)Connection to the PC (19)Screen Elements (20)Thought Support (20)Settings Menu (21)Chapter 2 (25)SEMG sessions on your MYOTRAC INFINITI™ Dual SEMG Encoder (25)Open SEMG Sessions (25)Script SEMG Sessions (27)Chapter 3 (28)Data Management on your MYOTRAC INFINITI™ Dual SEMG Encoder (28)MyoTrac Infiniti Review (29)Chapter 4 (30)Display Options on your MYOTRAC INFINITI™ Dual SEMG Encoder (30)Displays (30)Chapter 5 (34)Flow on your MYOTRAC INFINITI™ Dual SEMG Encoder (34)Chapter 6 (35)Reference (35)Technical Support and Order Placing (36)Technical Support (36)Product Numbers & Accessories (37)Placing Orders (38)Specifications (39)MyoTrac Infiniti Hardware Copyright Notice (44)About This Guide Welcome to the MYOTRAC INFINITI™ encoder. This guide is designed to help you get up and running quickly with your new encoder. It will describe the operation of the encoder, and how it interfaces to the host personal computer (PC).It walks you through:•Physical Operation of the encoder.• EMG sessions.• Data management.• Display options.After you have become familiar with the key concepts of your new encoder, you can use the rest of this guide as a reference for less common tasks, and also as a source of information if you have problems operating it.Chapter 1 Introduction to your MYOTRAC INFINITI™ Dual SEMG EncoderThis chapter explains the physical interface with the MyoTrac Infiniti Encoder, how to use it for the first time, and how to transfer data to the host PC.Getting to know your MyoTrac Infiniti Dual SEMG EncoderWhat is a MyoTrac Infiniti Dual SEMG Encoder?The MyoTrac Infiniti is the cutting edge in handheld, dual channel Surface Electromyography(SEMG). With it you will be able to deliver targeted and customized treatment directly to the client’s clinically relevant areas.A simple first approach has been adopted in the design of the MyoTrac Infiniti to make it as easyand fast as possible to get the clinical results desired from this powerful device.Customizing the MyoTrac Infiniti to your clinical needs couldn’t be easier; all users input is directed through a series of intuitive and guided screens using touch screen technology.The partnership of the MyoTrac Infiniti with the BioGraph Infiniti PC software enhances yet further the power and flexibility of the MyoTrac Infiniti. This link enables you to transfer session data to the PC for further viewing, analysis and reporting, in real time or post session.System RequirementsTo install the BioGraph Infiniti software, your computer system must meet or exceed the following requirements.•IBM PC compatible(Intel/Pentium/Celeron family or AMDK6/Athlon/Duron family, CPU P4 speed 3GHz or higher), Desktop or Laptop withtwo monitor capability•Windows 2000/XP Professional or Home edition.•50 - 60 gigabytes hard disk space for video recording and processing. (Thesoftware needs 2.5 gigabytes to installand run on available hard drive space) •Memory, 512 MB of RAM or more•CD ROM or DVD drive•SVGA graphic card (1024 x 768) or higher resolution adapter & monitor•32 bit Sound Blaster compatible sound card & speakers• 1 to 4 USB ports, depending on thedesired number of MyoTrac Infinitiencoders•Mouse or compatible pointing device •MS Word 97 or higher (for printingpurposes)•Compact Flash Reader (For use with compact flash card only)•Webcam 30 frames per second (for video purposes only)NOTE: When using certain more complex screens, you must adhere to the Recommended Computer Requirements.••IBM PC compatible(Intel/Pentium/Celeron family or AMDK6/Athlon/Duron family, CPU P3speed 1.8 GHz), Desktop or Laptop •Windows 2000/XP Professional or Home edition.•10 - 20 gigabytes hard disk space •(The software needs 2.5 gigabytes to install and run on available hard drivespace)•Memory, 256 MB of RAM or more •CD ROM or DVD drive•SVGA graphic card (1024 x 768) or higher resolution adapter & monitor •16 Bit Sound Blaster compatible sound card & speakers• 1 to 4 USB ports, depending on the desired number of MyoTrac Infinitiencoders•Mouse or compatible pointing device •Word 97 or higher (for printingpurposes)NOTE: For most recent computer requirements contact Thought Technology Ltd for MAR473Update informationPeriodically updates may become available for the BioGraph Infiniti software and for the MyoTrac Infiniti Hardware. Please contact your local distributor or visit our website for further information on how to obtain updates.MyoTrac Infiniti Components•Compact Flash for increased memory capacity and one method for transfer of data to the PC.•USB for real time transfer of data to the PC.•Touch screen enables graphically guided navigation through the software.•Rugged Ergonomic Case, easy to hold or attach to the subject and will withstand the rigors of daily use.•Battery Charging jack for wall connection enables fast built-in battery charging.•Headphone Jack for stereo sound feedback (or use the built-in speaker).•Push button On/Off switch to prevent accidental switching.• 2 Channels of Surface EMG.PowerThere are three basic methods to power the MyoTrac Infiniti unit: Inserting batteries into the battery compartment of the unit, plugging it into the wall using the supplied AC adapter, or plugging it into a powered up computer using a USB cable.The MyoTrac Infiniti is available with battery charging capabilities. It will work with four standard Alkaline AAA batteries available in all consumer electrical stores. It is also possible to run the unit on removable, externally rechargeable batteries. A rechargeable battery pack is supplied with the MyoTrac Infiniti and can be charged while still inside the unit.Note: When changing batteries it is recommended to plug the unit into external power, either USB or wall transformer so that data is not lost. Failure to supply external power will result in data and script loss.The battery compartment cover slides open by pushing up using the notch provided. Place four AAA batteries in the slots, observing the polarity as illustrated. Please note that a diagram of the correct battery polarity is embossed on the inside surface of the compartment.Alternatively it is possible to use a rechargeable battery pack (Thought Technology Part Number MI1028). This battery pack is plugged into the connector in the battery compartment marked BATT. The pack then fits into the normal battery area. Note: only use battery packs from Thought Technology or authorized representative, as use of other battery packs will damage the device.A wall mounted AC power adapter, supplied with the MyoTrac Infiniti, is used to connect the unit toan electrical outlet. This can be used in conjunction with the batteries or without.The unit can also be powered from the computer via the USB cable. The cable is connected to the unit on one side and on the other side to the USB port of the computer. This can be used inconjunction with the batteries or without.Charging the BatteriesNote: exact power supply subject to change without notice.Internal ChargerIf your MyoTrac Infiniti was supplied with a wall mounted AC adapter it is possible to charge the battery pack while it is inserted in the device.Note: Only use Thought Technology Ltd supplied wall mounted chargers with this device. Failure to do so could result in potential injury. Use only GlobTek Part Number WR9אB2500LCP-Y-MED where א= 2 for North America, א=3 for Europe, א=5 for United Kingdom and א=7 for Australia with the exception of Japan where the part number is GS 889.To start the charging plug in either the wall mounted AC adaptor or the USB cable. A full charging cycle from fully empty to fully charged will take approximately 2hrs for AC adaptor and 5.5hrs for the USB cable. The unit can be used while plugged in to either power source. The charging cycle does not need to be completed in full; it can be stopped at anytime by removing the connector.When the unit is turned off while plugged into an external power source, the screen displays a battery symbol. Charging action is shown with an animation of the battery filling up. When the battery is fully charged, the symbol shows a full battery.If the unit is plugged into an external power source while it is turned off, it will start charging within one minute.The state of the battery charging is available by going to the power menu in the settings menu of the device. It indicates the current mode of power and whether the unit is currently charging the batteries.Note: The rechargeable batteries must be fully charged prior to initial use. In order for the batteries to reach full capacity it may be necessary to charge them several times (~2-8) after initial use.MemoryRecorded data can be saved using three methods - choose the one which most closely matches your usage needs. To select saving method, select the Settings menu from the main menu, and tap on the Save icon.•Internal Memory – Limited size, only the statistical summaries are recorded. Specifically, the statistics for 13 open sessions or 9 training sessions (work/rest) or 6 assessment sessions(work/rest + fast-flick + endurance) can be recorded. Data can be lost if the batteries areremoved from the unit for longer than a few minutes.•Compact Flash Card – Most flexible method of data saving: save all the raw data for review on the encoder or for download to the PC. Available in most electronics stores in a range ofmemory sizes. Since all EMG data is recorded, the amount of data that is saved to thecompact flash card depends on the size of the card:hours64MB 1.75128MB 3.5 hours256MB 7 hours512MB 14 hourshours1GB 27.5hours2GB 55.5The encoder is delivered with a protective insert in the compact flash slot. To remove it, push the button next to the slot once to eject the card. The CF card can then be inserted; you willnotice that the CF card can only be inserted one way into the encoder to protect from incorrect insertion. When inserted properly it will be flush with the encoder rear. Follow the procedure above to remove this card when no longer required, and re-insert the protective insert. CFcards require a CF card reader to transfer data to the PC. The CF cards and reader can bepurchased from most computer stores. Before its first use in the encoder, a CF card requires PC formatting using the file manager, then format the card using the BioGraph Infiniti MainApplication. Formatting and transferring CF data to the PC is covered in depth in theBioGraph Infiniti software manual.•Real Time PC Transfer – Connect to the PC via the USB and save and display the data on the PC in real time. See the following section “Connection to the PC”.Attention: Do not remove the CF card without first stopping recording. If the CF card is removed during recording, you will lose all the data for the current session.TappingLike using a mouse on a computer screen the MyoTrac Infiniti allows you to use your finger or a stylus to tap the buttons directly on the screen. The first time you start your handheld unit, or if the power has been disconnected for a while, you will be guided through a set of welcome screens including calibration, time and date setting. The calibration aligns the internal circuitry of theencoder with its touch sensitive screen so that when you tap a button on the screen, the handheld unit can detect exactly which button is being pressed. It is recommended to use a stylus when calibrating the device as it will provide a more accurate calibration than using a finger.Note:Always use a finger or stylus for tapping the screen. Never use a pen, pencil or othermarking or sharp object on the screen.Damage resulting from misuse of the screen is notcovered by the warranty.The software is designed so that once the screen has been calibrated it is possible to use all the buttons with a finger. In many cases the touch sensitive area is greater than the graphicalconstraints of the button allowing for easier operation using a finger. As necessary wipe screen with a dry cloth to clean. Screen protectors are available from good stationary suppliers and are a good way to extending the life of your screen.Connection to the ClientDepending on the type of session you are going to record there are different ways to connect the two channels to the client. Either plug the extender cable into the device directly and connect to the client with EMG electrodes, or plug them into the pre-amplifier and the pre-amplifier into the MyoTrac Infiniti.Attention: When you insert the extender cable (lead wire) into the electrode connector, MAKE SURE THAT NO BARE METAL OF THE PINS IS EXPOSED.Before applying electrodes, be sure the skin surface is cleaned and dried. Make sure theelectrodes are placed firmly to the skin and make good contact between the skin and electrodes.Please consult the clinical guide for information on electrode selection for different placements. The illustration below shows the division of the body into six areas of treatment.Arms and ShouldersHead and NeckAbdominalsBack and ButtocksLegs and HipsWhen connecting a sensor or extender cables, be sure to properly line up the guiding dot on the top of the plug with the notch in the encoder's input socket. Forcing the plug into the jack in any other position may damage your equipment.Using the MyoTrac Infiniti with AC Power Adapter or Connected to a PCThe MyoTrac Infiniti is designed for safe operation on ungrounded AC power sources. However, if you are using the MyoTrac Infiniti while it is connected to an ungrounded AC power source, for best results you may need to follow some simple guidelines for skin preparation and electrode placement. These measures will help to avoid falsely elevated EMG readings while the muscle is at rest.If you notice elevated resting EMG levels not related to the patient’s condition, and if this occurs only when the unit is connected to AC power (directly via the supplied AC adapter or indirectly via a USB connection to the PC), and if it is necessary to run the MyoTrac Infiniti on ungrounded power(i.e. no 3rd ground pin on the AC wall socket or on the PC power supply), try the followingtechniques to improve the readings.First, if you are using a PC with only 2 prongs on the wall plug and you have a grounded outlet (3 pin wall sockets with a working ground), plug the ac adapter into the MyoTrac-Infiniti and into the grounded outlet to provide a ground for the system.If you have no opportunity to ground either the PC or the AC adapter, use the following electrode placement tips:•If the EMG site is located on an extremity or limb, be sure to place the REF (black colored) electrode more proximally (on or closer to the trunk of the body) than the sense electrodes(yellow and blue), and at least ten centimeters away from either sense electrode.•Prepare the skin under all three electrodes, using a product designed for skin preparation prior to electrode application (mild abrasives such as NuPrep are effective).•If you are using Ag/AgCl (silver/silver chloride) electrodes, put some conductive electrode paste or cream on them before applying them to the skin, or try using gel-type rather than dry Ag/AgCl electrodes.Resting EMG readings will not be affected by connection to AC power, in the following cases:•Running the MyoTrac Infiniti stand-alone, with no AC power adapter and no connection to the PC (only on its rechargeable batteries).。

两挡变速器纯电动汽车动力性经济性双目标的传动比优化_周兵

(
)
（ 6）式中： P em1 为满足车辆匀速爬坡性能要求的驱动电机峰值功率，求得 P em1 ≥18. 6kW。驱动电机的峰值功率还须满足汽车在平坦良好路面上的加速性能要求，根据设计时所参考的基础车的加速特性，取换挡车速为 20km / h，汽车从静止连续换挡加速到最高稳定车速的时间为 100 1 20 δ1 m δ2 m t = dua + dua ≤ 15 3. 6 0 Ft1 － Ff － FW 20 Ft2 － Ff － FW
Zhou Bing，Jiang Qinghua ＆ Yang Yi
Hunan University，State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body，Institute of Space Technology，Changsha 410082
(
CD A 3 mgf u max + u max 3 600 76 140
)
（ 5）
2
2. 1
动力系统参数匹配
驱动电机的选型
式中： P e1 为驱动电机的额定功率； u max 为汽车最高稳定车速。求得 P e1 ≥13. 3kW。驱动电机的峰值功率应满足汽车匀速爬坡性能的要求，则根据式（ 4 ）有 mgsinα m CD A 3 1 mgfcosα m P em1 ≥ ui + ui + ui 3 600 76 140 η T 3 600
* 中央高校基本科研业务费专项（ 531107040149 ）、教育部长江学者与创新团队发展计划项目（ 531105050037 ）和湖南大学汽车车身先进设计制造国家重点实验室自主研究课题项目（ 60870002 ）资助。原稿收到日期为 2010 年 3 月 18 日，修改稿收到日期为 2011 年 3 月 25 日。

新型钾离子电池的制备及性能研究

摘要锂离子电池（LIBs）是目前市场上最先进的便携电子产品和电动汽车等的电源，是21世纪最有潜力的大规模储能应用技术之一。

然而，由于全球锂资源匮乏，锂离子电池成本较高。

研发低成本、高性能、长循环寿命的新型储能体系已经刻不容缓。

钾离子电池作为锂离子电池的替代者，近年来得到人们关注，其中大部分工作是对钾离子电池正负极材料的研究，并没有制备出电化学性能优异的钾离子全电池。

本课题设计一种新型的多离子体系的钾双离子电池，将锂、钾杂化与钾型双离子电池相结合进行深入的研究讨论，优化电解液配方，制备电化学性能优异的新型钾离子电池，对电池的反应原理和机制进行深入的表征分析。

对不同杂化比例Li+/K+杂化离子电池的制备及性能研究。

首先对K+/Li+杂化离子电池的电解液进行了优化，对比几种配比的电解液用于K+/Li+杂化离子电池（主要以锂含量为20%和30%为例）的电化学性能，甄选出最优电解液配比为EC:EMC:DMC:PC=2:2:1:1。

然后配制了不同杂化比例的电池进行充放电性能以及电化学阻抗测试，当锂含量为20%时，电池具有较高的比容量、循环稳定性以及库伦效率，此时阻抗较低，电化学反应活化能也较低。

结合电化学阻抗、电化学反应活化能、循环性能测试，并且从减少锂资源消耗的方面考虑，我们选择锂含量为20%的杂化离子电池为最优杂化比。

对锂含量为20%的杂化离子电池进行倍率性能测试、反应机理分析及电化学性能提升机制的探讨。

电化学性能：25 C倍率充放电时放电比容量可达86.3 mAh g-1；5 C倍率循环500次后，放电比容量高达104.6 mAh g-1，容量保持率为99%。

通过负极XRD、XPS测试，分析出负极合金化产物为Li2Sn5和K2Sn5，通过MS模拟计算K2Sn5的标准PDF衍射图谱以及晶体结构。

通过正、负极材料在不同电压的非原位XRD、Raman测试，以及负极材料原位应力测试，表明电池具有良好的材料结构稳定性及反应物相可逆性。

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Performance Analysis of a Dual-Battery Scheme for Energy Efﬁciency inWireless Mobile TerminalsP.T.Dahake and A.ChockalingamDepartment of ECE,Indian Institute of Science,Bangalore560012Abstract—In this paper,we propose and analyze the perfor-mance of a dual-battery scheme which exploits the relaxation phe-nomenon in batteries(under pulsed discharge conditions)to in-crease the number of packets served during the life time of a bat-tery in wireless mobile terminals.Weﬁrst adopt a queueing the-ory based approach to model and analyze a dual-battery scheme. The batteries serve the packets based on random scheduling,i.e., a packet gets served by either theﬁrst or the second battery with probabilities and,respectively.We present an approxi-mate analysis to derive the expression for the expected number of packets served in the dual-battery scheme.We then study the per-formance of the proposed dual-battery scheme using the Lithium-ion battery simulation program from UC,Berkeley.We show that the dual-battery scheme achieves increased number of pack-ets served compared to a single battery scheme with intentional va-cations,without compromising on the packet delay performance. Keywords–Energy efﬁciency,relaxation phenomenon,dual-battery scheme,wireless mobile terminalsI.I NTRODUCTIONA challenging aspect in wireless mobile communications is exploring different ways by which the‘talk-time’in wireless mobile terminals can be maximized.In addition to develop-ing low-power circuits/devices,efﬁcient batteries and fuel cells, other means of energy savings(for example,through design of energy conscious protocols)in wireless networks have drawn signiﬁcant research attention.Another promising approach to improving energy efﬁciency in mobile terminals is to exploit the relaxation phenomenon in batteries[1].Several studies charac-terizing battery discharge behavior have shown that a battery can deliver more if it is discharged in a pulsed mode rather than in a continuous mode[2].This is because of the relaxation phenomenon in batteries by which a battery can recover its po-tential if left idle after a discharge[1],[2].The ability of a battery to recover its potential when left idle following a discharge has motivated several studies to exploit this phenomenon to increase battery life in wireless mobile ter-minals[3]-[6].The bursty nature of many data trafﬁc sources suggests that data transmission in communication devices may provide natural opportunities(idle periods)for such recovery. Single battery schemes which allow intentional vacations to the battery in order to exploit the relaxation phenomenon have been proposed and analyzed in[6],where it has been shown that al-lowing intentional vacations can increase the number of pack-ets served.However,such battery life gains came at the cost This work was supported in part by the Swarnajayanti Fellowship,Depart-ment of Science and Technology,New Delhi,Government of India,under Project Ref:No.6/3/2002-S.F.increased delay performance of the packets because packets are buffered and not sent during the intentional vacations.Our focus in this paper is to investigate multiple battery architectures with a motivation to exploit the relaxation phe-nomenon,but without compromising on the packet delay per-formance.In multiple battery schemes,when one battery serves a packet other batteries remain idle(during which the idle bat-teries can recover).Therefore,multiple battery schemes natu-rally allow recovery periods even without intentional vacations, which can avoid the penalty of increased packet delay due to intentional vacations.The key contribution in this paper is the proposal and analysis of a dual-battery scheme,in which the batteries serve the packets based on random scheduling,i.e., a packet gets served by either theﬁrst or the second battery with probabilities and,respectively.We evaluate the performance of the proposed dual-battery scheme througha queueing theory based analysis,and simulations using the Lithium-ion battery simulation program from UC,Berkeley[7]. We show that the dual-battery scheme achieves increased num-ber of packets served compared to a single battery scheme with intentional vacations,without loosing on the packet delay per-formance.II.B ATTERY D ISCHARGE/R ECHARGE M ODELAs in[6],we model the discharge and recharge behavior of the battery as shown in Fig. 1.While serving packets in busy periods,the battery is assumed to loose charge linearly at a constant slope of unity.During idle periods,the battery is assumed to recharge linearly with varying slopes depending on the battery level at the beginning of the idle period.Al-though the discharge/recharge behavior in batteries are nonlin-ear,the linear model considered here is an approximate,yet useful,model which allows mathematical analysis of the perfor-mance of various schemes that can exploit the relaxation phe-nomenon to achieve increased battery life.The recharge model is more clearly explained as follows.We divide the range of charge from to using threshold values,. The recharge slope is taken to be,respec-tively,when the battery level at the beginning of the idle pe-riod is in the range to,to,...,to.By choosing,the model ensures that the ability to recharge reduces with decreasing battery level,as in real bat-teries.Thus,the parameters’s,and’s characterize the recharge behavior.Fig.1.Battery discharge/recharge model.Random SchedulingFig.2.Dual-battery scheme with random scheduling.III.D UAL-B ATTERY S CHEMEThe proposed dual-battery scheme is shown in Fig.2.Twobatteries each with charge units are considered.We modelthe batteries as servers withﬁnite capacities and packets as cus-tomers to serve.We assume that the packet arrival process atthe mobile terminal is Poisson with rate,and the service timedistribution is exponential with parameter.A packet can beserved either by theﬁrst or by the second battery with proba-bilities and(),respectively.When one battery serves apacket,the other battery remains idle(i.e.,takes a natural va-cation).The batteries are assumed to discharge(during packettransmissions)and recharge(during idle periods)as per the dis-charge/recharge model described in Sec.II.A.Performance AnalysisWe are interested in analyzing the performance of the dual-battery scheme,in terms of mean number of packets served andmean packet delay.We deﬁne a cycle as shown in Fig.3.Inorder toﬁnd the expected number of packets served by the sys-tem,weﬁnd the expected number of packets served by boththe batteries till one of the battery expires(i.e.,battery chargegoes to zero),and the expected number of packets served bythe remaining live battery till it expires.To do that,we carryout the following analytical steps:1)obtain the distribution of the amount of charge left in eachbattery at the end of itsﬁrst busy period2)obtain the expected number of cycles after theﬁrst busyperiod of each battery till its charge goes to zero3)obtain the expected number of packets served in each cy-RemainingWorkServer1Server2Fig.3.Deﬁnition of a cycle in the dual-battery scheme.cle in each battery till any one battery expires4)after any one battery expires,using the charge left in theremaining live battery,evaluate the expected number ofpackets served by it till it expires,by considering the sys-tem as a single battery system without vacations.Consider the busy period of a queue.Let be ar.v denoting the number of packets served in a busyperiod.Let packets are served in this busy period.Let,,be the number of packets served by theﬁrstbattery during a busy period.Then packetswill be served by the second battery in the same busy period.We use the following notations:,:r.v’s denoting busy&idle periods of queue,:r.v’s denoting busy&idle periods of1st battery,:r.v’s denoting busy&idle periods of2nd battery:exponentially distributed r.v with parameter.We are interested in obtaining the distribution of the busy pe-riods of the two batteries.Exact pdf expressions for these busyperiods are difﬁcult to obtain.Hence,in order to facilitate theanalysis,we assume that theﬁrst battery serves the out ofpackets in a busy period continuously,and likewisethe second battery serves the remaining packets continu-ously.Note that in the actual system,the service of packets ina busy period by theﬁrst battery can be discontinuous(i.e.,service of packets can alternate randomly between the twobatteries depending on the scheduling probability,).Hencethis assumption is expected to give approximate ter,we will compare the results obtained through this approximateanalysis with exact simulation results.With the above assumption,the cdf of the busy period of theﬁrst battery can be written asPr packets are served in busy period,and out of packets are served by1st battery,and(1)The probability of having packets served in the busy period is given by[8](3) Since’s are,has Erlang distribu-tion.The pdf of the busy period of theﬁrst battery can then be obtained from(3),asSimilarly,the cdf and pdf of the busy period of the second battery can be obtained asPr(6)Next,we are interested in the distribution of the idle peri-ods of the two batteries.The idle period of theﬁrst battery in a cycle consists of two components,namely,the inherent idle period in a queue and the busy period of the second battery.Hence,the pdf of the idle period of theﬁrst battery can be written as(7)where denotes convolution operation,and. Eqn.(7),in transform domain,can be written as(8) where and are given by[9](10)Also,we can obtain the following Laplace Transform relation(11) where and are,respectively,the Euler Gamma function and the incomplete Gamma function,given by:integer,and.From the above,can be written as(14)We are now interested in obtaining the expected number of cy-cles after theﬁrst busy period of each battery till its charge goes to zero.Let be a r.v denoting the number of cycles till the charge of theﬁrst battery goes to zero,and let be a r.v de-noting the number of cycles till the charge of the second battery goes to zero.Weﬁrstﬁnd.Let(15) where is the charge consumed during the busy period of theﬁrst battery in the cycle,is the amount of recharge gained during the idle period in the cycle,and is net charge gained(or lost)in the cycle.Let be the r.v which denotes the charge at the end of theﬁrst busy period of theﬁrst battery.We need toﬁnd(16)Let denote expected number of cycles given that the charge after theﬁrst busy period is.Then we have(17)where is the cdf of.To obtain the distribution of ,we need to obtain the distribution of and.The dis-tribution of is obtained as follows.Let denote the charge at the beginning of cycle and let denote the duration of the idle period of the cycle of theﬁrst battery.Then= min,and(18)where,is the rate of recharge(as de-scribed in Sec.II),which depends on available battery charge at the start of the cycle.The value of,is determined by the charge threshold values between which lies.Since the battery discharge slope is unity,the distribution of is the same as the distribution of.Hence,the cdf of in(17)can be written as(19) To obtain,we average as(20)We can obtain by following similar steps used to obtain in the above.Let.Then the average number of packets served by both the batteries till one of the battery expires is given byLithium-ion Battery Simulation Results:We also studied the performance of the proposed dual-battery scheme using the battery simulation program devel-oped by the Chemical Engineering Department,UC,Berkeley [7].We evaluated the performance for the dual-battery scheme with random scheduling(DBS-RD scheme)as follows.First, we implement the packet arrival process,queueing and battery scheduling algorithm in a separate program.We run this pro-gram to obtain traces of the busy and idle periods of the two bat-teries.These busy and idle period traces are then given as inputs to the Berkeley Lithium-ion battery simulation program which incorporates the actual(non-linear)discharge/recharge charac-teristics of the battery.We run this battery simulation program till both batteries fall below their cut-off voltages.Statistics are collected during these simulation runs to obtain the expected number of packets served and the mean packet delay.Following a similar procedure,for comparison purposes,we evaluated the performance of two‘single battery like’(SBL) schemes,in which theﬁrst battery will continue to serve pack-ets till it drops below the cutoff voltage and only then the sec-ond battery starts serving.We consider a SBL scheme with exhaustive service)(i.e.,no intentional vacation),and another SBL scheme with non-exhaustive service(i.e.,allow intentional vacations).In non-exhaustive service scheme,the battery takes a exponentially distributed vacation time(with parameter) after continuously serving packets.We compare the per-formance of)DBS-RD scheme,)SBL Exhaustive Service(SBL-ES)scheme,and)SBL Non-exhaustive Service(SBL-NS)scheme.Since the total theoretical capacity is taken to be same for the SBL and the DBS-RD schemes,the performance difference between these schemes arise mainly due to the way in which the batteries are discharged in each scheme.Figs.6and7show the performance comparison between the DBS-RD,SBL-ES and SBL-NS schemes.The following obser-vations can be made from Figs.6and7.The DBS-RD scheme performs better than SBL-ES scheme(no intentional vacation) in terms of expected number of packets served.Their delay performances,however,are almost the same.The number of packets served is increased in SBL-NS scheme(compared to SBL-ES scheme)by allowing intentional vacations once every packets served.Even with intentional vacations with, the SBL-NS scheme performs poorer than the DBS-RD scheme in terms of number of packets served.Further,because of inten-tional vacations,the delay performance of the SBL-NS scheme is much poorer than the DBS-RD scheme.Thus,the proposed dual-battery architecture can provide both increased number of packets served as well as lesser mean delay compared to single battery schemes with intentional vacations.V.C ONCLUSIONSWe proposed and analyzed the performance of a dual-battery scheme which exploits the relaxation phenomenon in ing a queueing theory based approach,we analyzed the performance of the dual-battery scheme with random schedul-ing.We also carried out a detailed simulation study of theFig.6.,). 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