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ENHANCEMENT OF LIFETIME USING DUTY CYCLE AND NETWORK CODING IN WIRELESS SENSOR NETWORKS

ENHANCEMENT OF LIFETIME USING DUTY CYCLE AND NETWORK CODING IN WIRELESS SENSOR NETWORKS

 Random Duty-cycled WSN  Co-ordinate Duty cycled WSN In the former, the sensor nodes are turned on and off independently in random fashion. In the later, the sensor nodes co-ordinate among themselves via communication and control message exchanges. They are potentially efficient for communication. However, it requires additional information exchange to disseminate the active/sleep schedule of each node. The random duty-cycled WSNs are simple to design as no additional overhead is required. In this work, the primarily goal is to gain certain analytical understanding on the upper-bound of the network lifetime. Therefore, the random duty cycle based WSN has been considered for its simplicity in design. Specifically, the problem of reduction of traffic in the bottleneck zone has been considered.
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Vol 7, No 1 (2013)

Vol 7, No 1 (2013)

SDCS based on periodic scheduled wake up scheduled for data exchange which consists of the sleep period and an active period. Sensor node can communicate with each other when it in active mode otherwise in sleep mode radio of sensor node is off so they cannot communicate with each other. This approach reduces the idle listening time of the sensor nodes which leads to reduce the energy consumption of the sensor nodes and increases the lifespan of the network. Thus, scheme introduces coordinate sleep scheduled of all nodes to maintain the network level connectivity. The drawback of SDCS is that it increases the sleep latency in multi hope network .So when traffic load is more, it increase number of queue packets due to sleep latency. Many packets dropped due to buffered overflow which increases end to end latency of node. The end to end latency is inversely proportional to throughput. In WSN nodes generally deployed in different location requires different duty cycle to minimize the energy consumption and to increase the lifespan of network. For example, consider the parking system monitoring in malls, they continuously monitors the parked vehicles and data is continuously send to the from leaf node to sink or control system to observed the capacity of the parking place. So nodes deploy near sink needs to transfer the more data than leaf node. Which gives nodes deploy near the sink required different duty cycle according to traffic conditions. Dynamic duty cycle scheduling scheme are proposed to overcome these problems and to increase the energy conservation over the network.
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Energy optimal scheduling in low duty cycle sensor networks

Energy optimal scheduling in low duty cycle sensor networks

There are many works that offer low energy consumption in the literature [5], [6], [7], [8]. In all these works, the proposed algorithms and experiments have been designed by only taking into account the energy consumption in the active and sleep modes but they have not considered the consumed energy during switching from one state to another. In addition, none of these works deals with the network stability problem with the objective of minimum energy. In [9], the authors have proposed wireless sensor network protocols that take into account the source of energy consumptions in a network simulation model. They have also mentioned about switching energy but leaved it as an open research area. The study in [10] have considered switching energy cost since it has been observed that significant energy consumption occurs when switching from sleep mode to the active mode. On the other hand, in some studies like [11] it has been stated that the energy cost of switching is small. Generally, it is common to ignore switching energy in the literature. There are also various approaches proposed for designing duty cycling protocols [12], [2], [13], for sleep mode protocols [14] and for routing protocols [15], [16]. All of these works try to maximize the lifespan or the utility of the network without considering the network stability problem.
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A Novel Energy Efficient Routing for Data Intensive MANETs

A Novel Energy Efficient Routing for Data Intensive MANETs

Duty cycle is the combination of both long and short cycle per transmission. To conserve energy, we are not going to keep the nodes in active state always rather we are switching the nodes from active to sleep when there is no packet to transmit and switching the nodes from sleep to active when there are packets to transmit. The source prefers short duty cycle and makes the long duty cycle nodes to sleep. A node comprises of both long and short cycle and is active in one half of the duty cycle and idle in the other half of the duty cycle .Which means we are not using the entire duty cycle of the node, only one half is used for any transmission. For the first time alone the route is pre-determined from the next transmission onwards, the routes are dynamic for route discovery we are using RTS and broadcast discovers all possible paths and RTS confirms one path among the all. Here the source terminates the links when there is no active transmission that is before transmission, the node checks for the intermediates duty cycle if the duty cycle is long, it terminates if not it transmits data.
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The influence of thermal acclimation on power production during swimming  I  In vivo stimulation and length change pattern of scup red muscle

The influence of thermal acclimation on power production during swimming I In vivo stimulation and length change pattern of scup red muscle

Duty cycle was calculated from the average duration of five EMG bursts divided by the tail-beat period of the fish. Burst duration was measured from the first to the last spike of an EMG burst (see Fig. 2 for examples). This manual method of duty cycle measurement was compared with an automated method of measuring duty cycle. The on- and off-times of an EMG burst were automatically selected using a software routine based on spike amplitude after differentiating and rectifying the EMG traces. Therefore, EMG spikes were separated from background noise not only by amplitude, but also by slope. This procedure removed motion artefacts occurring at the end of the EMG burst. In addition, the number of EMG spikes per 20 ms bin was counted using custom-designed signal-processing macros (Datapac, Run Technologies) based on criteria developed previously (Rome et al., 1992).
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High duty cycle echolocation and prey detection by bats

High duty cycle echolocation and prey detection by bats

Field and laboratory data showed that longer pulse durations and a higher duty cycle translated into higher flutter detection performance because temporal variables are important to aerial- hawking bats in forested habitat. At higher duty cycles, it may be easier to detect, track and lock onto a fluttering target because the silent period between calls is dramatically reduced. Enhanced tracking of flying targets by HDC bats is a function of their approach to avoiding self-deafening (separating pulse and echo in frequency). Additionally, longer signals are better for encoding target movements because of relatively uninterrupted modulations in echo amplitude and frequency (Schnitzler et al., 2003). Although increased pulse length can be advantageous for LDC bats, the constraint imposed by pulse–echo overlap limits call duration.
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Daily rhythms of the sleep-wake cycle

Daily rhythms of the sleep-wake cycle

The changes in sleep with aging might be explained in terms of altered S and S ’ processes. Investigations of responses to altered sleep-wake schedules (advancing or delaying bedtime, for example) have shown that changes similar to those found in younger adults under the same circumstances are found for many sleep variables, including sleep efficiency and time awake after sleep onset [119]. The increase in sleep latency with age has been taken to imply that sleep pressure decreases but, again, contradictory results have been obtained. SWS during the first part of a night’s sleep is normally decreased in the aged [120,121]. The rate of dissipation of S (S ’ , as assessed from SWA) does not differ from that found in younger adults and, as in them, the amount of SWS increases following sleep-deprivation [122] and decreases in nocturnal sleeps taken after day- time naps [123]. On the other hand, another study claimed that the relationship between SWS and prior wakefulness was different between aged participants and younger controls [116] and that daytime naps led to a fall in sleep efficiency and earlier waking [124]. Several differences in the power of different frequency bands in the EEG have been found in aged individuals compared with younger controls [120], though their detailed meaning is unclear.
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Design And Simulation Of Dc-Dc Switching Boost Converter For Current Ripple Reduction

Design And Simulation Of Dc-Dc Switching Boost Converter For Current Ripple Reduction

related to parameters that are varied (frequency and duty cycle). This is because, the frequency determines how many pulse it is in a second. The higher the frequency, the faster the switching process within a second it is. As for the duty cycle, it controls the switching of the boost converter for the on and off state. It is either the turn on state is longer than the turn off state causing the time for the inductor to charge slower and to discharge faster or the opposite. As for the third and forth objective, it has been accomplished throughout the implementation of the project. The DC-DC switching boost converter for current ripple is modeled, simulated and analyzed using the MATLAB software and the hardware prototype of the DC-DC boost converter is developed with a switching control from a program developed in the DSP TMS320F2812.
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Effect of Duty Cycle on the Corrosion of Mg PEO Coatings

Effect of Duty Cycle on the Corrosion of Mg PEO Coatings

In a study conducted on AA7075 alloy [18], the use of low-duty cycles increased polarization resistance and adhesion of the coating to the substrate; this was such that the test results of open circuit potential (OCP) were altered in terms of time, showing the higher levels of OCP in the coatings of low duty cycles; this, in turn, verified less susceptibility to corrosion. Also, the analysis of the surface roughness (Ra) of the coatings created in different duty cycles showed that the coatings made in the lower duty cycle had the lowest surface roughness, as well as a smoother coating. In a research that addressed Al6061 alloy [17], it was found that the coatings created in the lower duty cycles had a higher breakdown voltage and higher density sparks, leading to the smoother silicon distribution on the coating surface. Research results on titanium alloy have also shown that the lower duty cycle coating could increase the micro-hardness of the coating [19].
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Analytic Conditions for Energy Neutrality in Uniformly-Formed Wireless Sensor Networks

Analytic Conditions for Energy Neutrality in Uniformly-Formed Wireless Sensor Networks

Concerning the data gathering itself, we created artificial data via a custom Matlab function that, starting from the rand() function, generates data with Uniform, Pareto, Expo- nential and Half-Gaussian distributions (considered in Section III) via rejection sampling [44], with mean transmission rate equal to r = 24 kbps. The data is copied onto each node and it is read from its external flash memory during the steady-state active mode. This ensures that: (i) we match the different PDFs under consideration and (ii) the energy to retrieve this data from the flash memory replaces the sensing and processing energy that would have been dissipated if the data had come from an actual sensing process.
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Derivation of a Representative Engine Duty Cycle from On Road Heavy Duty Vehicle Driving Data

Derivation of a Representative Engine Duty Cycle from On Road Heavy Duty Vehicle Driving Data

The heavy-duty vehicle fleet involved in delivering water and sand makes no- ticeable issues of exhaust emissions and fuel consumption in the process of shale gas development. To examine the possibility of converting these heavy-duty diesel engines to run on natural gas-diesel dual-fuel, a transient engine duty cycle representing the real-world engine working conditions is necessary. In this paper, a methodology is proposed, and a target engine duty cycle comprising of 2231 seconds is developed from on-road data collected from 11 on-road sand and water hauling trucks. The similarity of inherent characteristics of the developed cycle and the base trip observed is evidenced by the 2.05% error of standard deviation and average values for normalized engine speed and engine torque. Our results show that the proposed approach is expected to produce a representative cycle of in-use heavy-duty engine be- havior.
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Modified Perturb and Observe Algorithm for Drift Avoidance in PV System Using Neural Network

Modified Perturb and Observe Algorithm for Drift Avoidance in PV System Using Neural Network

Most PV arrays use an inverter to convert the DC power produced by the modules into alternating current that can power lights, motors, and other loads. The modules in a PV array are usually first connected in series to obtain the desired voltage; the individual strings are then connected in parallel to allow the system to produce more current. Solar panels are typically measured under STC (standard test conditions) or PTC (PVUSA test conditions), in watts. Typical panel ratings range from less than 100 watts to over 400 watts. The array rating consists of a summation of the panel ratings, in watts, kilowatts, or megawatts.The operating point on the characteristics of the PV module primarily depends on the impedance matching of the PV module with respect to the connected load. A DC-DC converter between the PV module and load acts as an interface to operate at MPP by changing the duty cycle of the converter generated by the MPPT controller and a general block diagram of PV system.
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A Bi Polar Triple Output Converter with Duty Cycle Estimation

A Bi Polar Triple Output Converter with Duty Cycle Estimation

This paper proposed an alternate converter with a main and an auxiliary inductor, capable of generating both positive and negative outputs and in both buck and boost configurations. The topology does not involve any re- verse power flow to the supply and hence time periods can be shorter and higher power levels are possible. The topology is validated through simulation using PSIM software and further through hardware results obtained with a Spartan FPGA system. The suggested topology is generic and is extendable to more outputs. A novel control method through duty cycle estimation has been suggested which is capable of regulating output voltages against line and load disturbances. Since the duty cycles of the next time period are estimated in the present cycle by direct computation, the control method is capable of overcoming cross-regulation issues.
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A Wide Range All Digital Feedback Duty Cycle Corrector

A Wide Range All Digital Feedback Duty Cycle Corrector

IV. RESULTS AND DISCUESSIONS The model of the proposed MSAR-DCC has been implemented in a standard 0.18µm CMOS technology, by using CADENCE software. The active area is 0.033mm 2 . Fig. 4.1 shows the calculated output clock waveform of the MSAR- DCC. The output of the DCC is corrected to 50% only within 5 cycles and Power consumption is calculated as 5581nW. Among the usual feedback type DCCs, this digital-feedback DCC has the smallest duty-correction time with the highest duty rate accuracy.

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Design of PWM with Variable Duty Cycle for Efficient Power Analysis

Design of PWM with Variable Duty Cycle for Efficient Power Analysis

This paper proposes to spread the switching of clock tree drivers in an try to decrease the peakcurrent, while preserving the clock sign pleasant and low skew [r]

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Sliding   Mode  MPPT   Based Control For a Solar Photovoltaic system

Sliding   Mode  MPPT   Based Control For a Solar Photovoltaic system

photovoltaic (PV) system by sliding mode control(SMC). Here, open circuit voltage MPPT technique is used to track maximum power point. There is a difficulty in tracking the maximum power point of the photovoltaic system due to nonlinearity of the I-V characteristics which is dependent of the temperature and irradiation conditions. The system involves a PV panel, dc/dc boost converter, a load and a control that generates PWM signal that goes to the boost converter. The open circuit voltage based MPPT uses open circuit voltage to calculate maximum power output voltage. The input to the sliding mode controller is the change in reference voltage and PV voltage and the output of the SMC is the change in duty ratio. The SMC is used to track the maximum power point by changing the duty cycle of the boost converter. Using this method, the output power of PV array directly controls the dc/dc converter, hence reduces the complexity of the system. The advantages of this method are high efficiency, best accuracy, good convergence speed, and is robust to weather condition changes. The effectiveness of proposed sliding mode control can be validated using simulation
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SLEEP SCHEDULING FOR GEOGRAPHIC ROUTING IN DUTY CYCLED MOBILE SENSOR NETWORKS

SLEEP SCHEDULING FOR GEOGRAPHIC ROUTING IN DUTY CYCLED MOBILE SENSOR NETWORKS

In recent year, a lot of research work has been proposed on routing scheme in WSN. Geographic routing is one of the most promising techniques due to its simplicity, scalability, and efficiency. We focus on sleep scheduling problems in duty cycle of node with geographic forwarding mechanism. In WSN, because of duty-cycled, latency issues arise and most of opportunistic routing protocols have been proposed to handle this problem by adjusting the geographic forwarding. GCKN sleep scheduling overcome existing geographic routing designed for static WSN. We are proposing a new scheme to minimize transient delay among node, resulting in reduce duty-cycle, low energy consumption and minimized network latency. Proposed system is designed by keeping the multipath broadcast methodology for data sinking for receiving end. This will create multiple path for transferring data from sender to receiver and every path and every node will auto decide to go in sleep and wake up state after communicating with each other. This will solve data flooding problem, improve network efficiency and save energy
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Extended Maternity Leave and Breastfeeding in Active Duty Mothers

Extended Maternity Leave and Breastfeeding in Active Duty Mothers

All infants born to active duty military mothers during the defined time period at BAMC were included for evaluation. Infants were excluded if they did not receive well-child care within an MTF until at least 2 months of age. Examples of this exclusion criterion include infants who received care in civilian health care systems, infants who did not attend regularly scheduled well-child visits, or infants whose parents separated from the military. Infants were also excluded if they had a documented medical contraindication to breast milk or died before 12 months of age. Multiple-gestation deliveries were counted as an independent metric (singleton versus multiple delivery) during evaluation of the study demographics. However, only a singular mother-infant dyad was analyzed to maintain equal numbers of infants and mothers in the study. For every multiple delivery, the data of the youngest living infant
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Reliability Assessment and Thermal Consideration of a Step-down DC/DC Converter

Reliability Assessment and Thermal Consideration of a Step-down DC/DC Converter

Reliability consideration is always important among the manufacturers of power modules and converters. Before using of power electronic converters into the related application, it is necessary to predict its reliability over time. In the meanwhile, the power loss and heat generated within the power semiconductors play a key role in the lifespan of the whole system. In this paper, a method for assessing the reliability of a step-down DC-DC converter is employed based on the thermal modeling of power semiconductors. As is evident from the used reliability approach, the junction temperature of power semiconductors – diodes and insulated-gate bipolar transistors (IGBTs) – is the most influential factor on the lifetime of power converters. Therefore, the simultaneous influence of switching frequency and duty cycle is analyzed at the same time as a factor for evaluating reliability. A cut-off of 150°C is considered for the maximum allowable junction temperature for the examined IGBT power module. The results show that a failure can be expected after 46,000 hours of operation of the considered power converter. Additionally, 3D curves are presented to illustrate the influence of duty cycle and switching frequency on the reliability of circuit’s components and the overall system. The obtained results confirmed that an increase in switching frequency from 1 kHz to 10 kHz can decrease the circuit’s lifetime almost 22%.
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A case of popliteal artery entrapment in an active duty soldier

A case of popliteal artery entrapment in an active duty soldier

Introduction: Popliteal Artery Entrapment Syndrome (PAES) is a less considered entity in active patients presenting with exertional lower extremity pain with associated claudication. Median time to diagnosis can be as high as 12 months and delay in surgical intervention can lead to increased morbidity. After treatment, recovery is promising with most patients returning to cardiovascular activity after three months. Case Report: We present the case of a 27-year-old active duty Caucasian male who initially presented for exertional right greater than left leg pain and was found on testing in the clinic to have absent distal extremity pulses with exercise. CT imaging revealed evidence of popliteal artery entrapment and surgical intervention was later pursued. We focus on the difficulty in diagnosing the condition given the plethora of other conditions that can present similarly. Furthermore, we discuss diagnostic modalities available along with management options available to the primary care physician. Conclusion: It is important to have a high index of suspicion for PAES in patients presenting with exertional claudication in the lower extremity and to understand what immediate testing can be done in the clinic and after evaluation, that can aid in diagnosis and management.
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