Power Con Research Articles

Evaluating the Efficacy of Eccentric Half-Squats for Post-Activation Performance Enhancement in Jump Ability in Male Jumpers

The purpose of the present study was to investigate effect of post-activation performance enhancement (PAPE) induced by the eccentric half-squat exercise on vertical jump performance in male jumpers. The jumping height, peak power, and work were measured and evaluated in twenty male jumpers (age: 21.2 ± 1.7 years, height: 191.1 ± 3.3 cm, body mass: 81.56 ± 7.3 kg) who participated in the national championship last year. Participants performed five eccentric half-squats at 85% of their one-repetition maximum (1 RM), with a knee angle below 90°, followed by immediate and 2 min delayed jump assessments using the Squat Jump (SJ) and Countermovement Jump (CMJ) tests. Results showed that this specific PAPE protocol did not significantly improve jump performance for the SJ (Height: ES = 0.613, p = 0.462, Work: ES = 0.124, p = 0.231, Power: ES = 0.382, p = 0.125) or CMJ (Height: ES = 0.523, p = 0.368, Work ecc: ES = 0.133, p = 0.505 (only main effect time p < 0.05), Work con: ES = 0.114, p = 0.101, Power ecc: ES = 0.134, p = 0.177, Power con: ES = 0.182, p = 0.195, Leg stiffness: ES = 0.095, p = 0.358) tests. Factors such as stimulus specificity, rest intervals, muscle length, and the balance between potentiation and fatigue may explain these results. This study highlights the complexity of PAPE responses and suggests that a single set of eccentric squats with a short rest may not improve jump performance in male jumpers. Further research is required to optimize the interplay between conditioning stimuli and rest periods to maximize PAPE effects in athletic performance enhancement.

Resonant Radar Reflector On VHF / UHF Band Based on BPSK Modulation at LEO Orbit by MRC-100 Satellite

This paper presents a novel method for identify ing and tracking PocketQube satellites: the MRC-100 satellite is a model, and this method is based on a resonant radar reflec tor. The resonant reflector’s basic concept is that the resonant reflector uses a VHF/UHF communication subsystem antenna; there is no radiated RF signal, which means the power con sumption is only some Milliampere (mA). The continuous wave (CW) illuminator RF source is on the ground, and the onboard antenna receives the CW RF signal from the Earth. The micro controller (uC) periodically switches PIN diode forming BPSK modulated signal reflection so that another Earth station can receive the backscattered Binary Phase Shift Keying (BPSK) modulated signal. Also, it can detect the satellite if the ground station receiver can use a matched filter like a correlation re ceiver. If the ground station receiver knows the BPSK code of the satellite, it can detect it. If not, there is no way to detect the satellite. This method is similar to Radio Frequency Identifica tion (RFID) applications, but the reader is the ground station, and the tag is the satellite.

Performance Analysis of Notch Filter in ECG Signal Noise Reduction

An electrocardiogram (ECG) is a medical test that records the normal and abnormal condition of the heart. It is an essential tool for identifying vari- ous cardiac related issues. However, ECG wave are often distorted by diverse noise sources, such as movement artifacts or electrical interference. To remove these artifacts and enhance the quality of the ECG signal, various filters are commonly used. The choice of filter type depends on the definite necessities of the application. FIR filters are used in the area that needs linear time response and accurate amplitude response. They have a stable and predictable response and are more robust to coefficient quantization errors. However, they require a larger number of coefficients to achieve the desired frequency response, which can lead to increased computational complexity. The use of digital filters, specifically notch filters, for denoising ECG signals is an effective technique. Adders are essential components in the design of notch filters, and researchers have been exploring different types of adders to improve the parameters of these filters. In this paper, the Ripple carry adder, Carry select Adder, and adder using Carry skip are compared in terms of their performance parame- ters, including area, delay, and power consumption. The RCA is a basic adder, while the C-Skip and C-Select adder are designed to reduce the delay of the addition operation. The results of the study showed that the C-Skip and C- Select adder outperformed the R-Carry adder in terms of delay and power con- sumption. The C-select adder had the lowest delay, while the C-Skip adder had the lowest power consumption. However, the area of the C-select Adder was larger compared to the other adders. Overall, the selection of adder depends on the particular need of the application. Notch filter used for ECG noise removal designed using these adders and its performance is analyzed.

Performance comparison of SRAM cells in 45NM technology in the presence of a memory cell control circuit

Lowering power consumption and increasing the noise margin have become the two most important aspects to be considered in SRAM design. Additionally, a stable operation with good memory retention capability has gained greater importance in obtaining good yield at low-voltage and low-power SRAM designs, due to the fact that parameter variations play a major role in scaled technologies. In this paper, the 6T SRAM, 7T low power SRAM and 7T multi threshold low power SRAM designs are designed, to incorporate power gating technique. The architecture of each of the SRAM designs and their working are analyzed thoroughly. The outputs of the read, write and hold operations with transient response are observed and the power dissipation and static noise margin (SNM) of the each of the SRAM cells is calculated and compared. The paper also presents new power reduction solution through the cell control circuit which reduces the unwanted and spurious switching activities during read and writes operations. The paper demonstrates the reduction of the power con- sumption through the use of cell control circuit.

Research on the Power and the Admission Control based on the Priority Mechanism in the Cognitive Radio

Cognitive Radio is the new technology which can optimize the utilization of the frequency spectrum. The Pri- mary User and the Secondary User utilize the same frequency spectrum so that the Signal-to- interference- plus-noise- ratio of the Primary User will be reduced. In order to ensure the Quality-of-Service of the Primary User, the Power Con- trol should be done to the Secondary User and the Admission Control should be combined to maximize the number of the Secondary User. In order to ensure the Quality-of-Service of the Secondary User, the Priority Mechanism is adopted to avoid the transmission interruption of the Secondary User. The simulated results show that the system performance is su- perior to the original algorithm.

A 31–45.5 GHz injection-locked frequency divider in 90-nm CMOS technology

We present a 31-45.5 GHz injection-locked frequency divider (ILFD) implemented in a standard 90-nm CMOS process. To reduce parasitic capacitance and increase the operating frequency, an NMOS-only cross-coupled pair is adopted to provide negative resistance. Acting as an adjustable resistor, an NMOS transistor with a tunable gate bias voltage is connected to the differential output terminals for locking range extension. Measurements show that the designed ILFD can be fully functional in a wide locking range and provides a good figure-of-merit. Under a 1 V tunable bias voltage, the self-resonant frequency of the divider is 19.11 GHz and the maximum locking range is 37.7% at 38.5 GHz with an input power of 0 dBm. The power con- sumption is 2.88 mW under a supply voltage of 1.2 V. The size of the chip including the pads is 0.62 mm0.42 mm.

Novel Structures for Cyclic Convolution Using Improved First-Order Moment Algorithm

This paper first presents a decomposition scheme to reduce the computation time and make the first-order moment- based cyclic convolution well suited for hardware implementation. By decomposing the fixed convolution kernel into similar subparts and using their preprocessing results as control signals, each sub- part of cyclic convolution can be calculated with a basic computing substructure. Due to the flexibility of decomposition, a trade-off between computation time and hardware complexity exists. And for a pair of fixed decomposition coefficients, the similarity among subparts leads to the time-efficient structure and the area-efficient structure for cyclic convolution without limitation on the convolu- tion length and the word length . Since the basic computing substructure only contains a simple control module, several circu- larly right-shift registers and accumulation units, there is no requirement for multipliers and large memory. Comparisons in terms of area-delay product, area-time product and power con- sumption with the existing memory-based structures have been made to demonstrate the efficiency and effectiveness of the pro- posed structures. Using the same metrics, the comparison results further show significant improvement of theproposed designs over the previous first-order moment-based structure.

Eigenvalue equation for an asymmetric left-handed metamaterial planar slab optical waveguide

In this paper, we have derived the exact eigenvalue equation by using the transmission line method for double negative metamaterial slab. The derived results have exactly matched with the existing results found in the literature. The unusual behavior of double negative metamaterial is predicted. Dispersion study, modified profile and the power con- finement factor have been predicted for the case of double negative metamaterials.

A Integer Non-linear Programming Model of Power Consumption of the Internet under QoS Constraints

The concept of energy-efficient networking has begun to spread in the past few years, gaining increasing popularity. According to several studies, the power con- sumption of the Internet accounts for around 10% of the worldwide energy consumption and is constantly increasing. On the other hand, with the increasing demand for various types of data traffic, especially delay sensitive traffic, the traditional best effort delivery no longer meets the Quality of Service (QoS) requirement for the applications, and strict QoS requirement needs to be considered. In this paper, we aim to minimize the power consumption of the Internet, while satisfying the strict QoS constraints in terms of delay. We propose an integer non-linear programming formulation of the power consumption model guaranteeing full connectivity under QoS constraints. Then, we propose simple heuristic algorithm and we use the algorithm on a synthetic topology. We evaluate our model through extensive simulations and it is shown that we could get minimum total cost consisting of power consumption and delay cost of the network when link utilization constraint is set to 75%. Index Terms—energy saving network; non-integer linear programming; QoS; heuristics

Power saving-aware prefetching for SSD-based systems

Energy saving for computing systems has recently become an important and worrying need. Energy demand has been increasing in many systems, especially in data centers and supercomputers. This article considers the problem of saving en- ergy on storage systems taking advantage of SSD drives. SSD and magnetic disk devices offer different power characteristics, being SSD drives much less power con- suming than conventional magnetic disk drives. This paper presents the design and evaluation of a novel power consumption-aware prefetching mechanism for hybrid storage systems. The prefetching mechanism aims to reduce the power consumption of high performance storage subsystems. Every disk access request is absorbed by an associated SSD device, and only when the SSD device is full, requests are forwarded to the disk in background. We have evaluated the proposed approach with the help of both synthetic and re- alistic workloads. The experimental results demonstrate that our solution achieves significant reduction in energy consumption. Additionally, the performance evalua- tion shows that our solution may bring a substantial I/O performance benefit.

¿Se pueden ejercer de forma omisiva las reglas que confieren poderes?

Este trabajo tiene el objetivo de demostrar cómo el poder jurídico puede ser ejercido no sólo de forma activa sino también mediante una omisión. Tomando como punto de partida la concepción de las reglas que confieren poderes de los profesores ATIENZA y RUIZ MANERO, así como un concepto de omisión tomado de VON WRIGHT, el autor argumenta, a través de varios ejemplos, cómo es posible ejecutar, mediante una omisión, reglas que confieren poderes de ejercicio facultativo. Finalmente, el trabajo analiza aquellos supuestos en los que el ordenamiento jurídico, ante determinadas conductas pasivas del agente a la ejecución de un poder de ejercicio obligatorio, establece una norma puramente constitutiva que atribuye un efecto jurídico a esa abstención, sin que ese caso pueda ser considerado como el ejercicio de una regla que confiere poder mediante una omisión.

Analysis and simulation of a‐Si:H/a‐SiC:H PINIP structures for color image detection

AbstractIt is presented in this paper a study on the photo‐electronic properties of multilayer a‐Si:H/a‐SiC:H p–i–n–i–p structures. This study is aimed to give an insight into the internal electrical characteristics of such a structure in thermal equilibrium, under applied bias and under different illumination condition. Taking advantage of this insight it is possible to establish a relation among the electrical behavior of the structure, the structure geometry (i.e. thickness of the light absorbing intrinsic layers and of the internal n‐layer) and the composition of the layers (i.e. optical bandgap controlled through percentage of carbon dilution in the a‐Si1–x Cx:H layers).Showing an optical gain for low incident light power con‐ trollable by means of externally applied bias or structure composition, these structures are quite attractive for photo‐sensing device applications, like color sensors and large area color image detector.An analysis based on numerical ASCA simulations is presented for describing the behavior of different configurations of the device and compared with experimental measurements (spectral response and current–voltage characteristic). (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

A Bibliographic Synthesis of Rhetorical Criticism

While conducting research for this article, I often came across this claim: Rhetorical criticism has traditionally been housed in speech communication de partments.1 One look at the bibliography for this article seems only to validate this claim; almost all of the journals and books are written by and for speech communication scholars. And really, this comes as little surprise when we con sider that the majority of the New Rhetoricians are communication theorists or that speech communication scholarship has been interested in analyzing specific communication situations. In all, the work of these scholars attempts to define the strategies employed, determine whether those strategies were effective to a specific rhetorical situation, and from that, articulate theories based on this care ful observation about different approaches to rhetorical criticism. However, I remain uncomfortable with making the claim that rhetorical crit icism grew up in speech communication, which to me implies that the field of rhetoric and composition does not have a history with rhetorical criticism. Yet many of the publications in our field give lie to that implied claim?Shirley Wilson Logan's We Are Coming: The Persuasive Discourse of Nineteenth Century Black Women, for example, conducts rhetorical criticism of the public discourses and speeches of nineteenth-century black women, while Ken McAllister's Game Work: Language, Power, and Computer Game Culture con ducts an in-depth rhetorical analysis of computer games in an effort to articulate a rhetorical theory that can account for games as a rhetorical text. The reason that rhetorical criticism has historically belonged to speech communication may simply be the fact that speech communication scholars have attempted to define and theorize it as a legitimate disciplinary concern. The purpose of this bibliographic synthesis is to provide rhetoric and composition scholars with a broad understanding of the field so that we can begin to theorize the work we do with rhetorical criticism and think through the ways in which we can enrich our own scholarship. Due to page-length limitations, I am unable to provide a synthesis of all the different approaches to rhetorical criticism. I have chosen to limit my scope to definitions, general methodology, and objects of rhetorical criticism, which com prise the first three sections. The final section will summarize four textbooks on rhetorical criticism, all four of which provide excellent starting places for those

Pulse evolution of a Q-switched ytterbium-doped double-clad fiber laser

We present pulse characteristics and evolution processes of a Q-switched ytterbium-doped double-clad (YDDC) fiber laser. At differ- ent pump powers and repetition rates, the laser shows different pulse shapes, buildup times, and duration. Due to the self-mode-locking effect in the Q-switching process, the Q-switched pulses split up. These phe- nomena are analyzed and the control of Q-switched pulses is discussed. applications. 3-5 High-energy pulses, up to multimillijoules, can be generated either from a Q-switched fiber laser di- rectly, or by using a master oscillator and power amplifier ~MOPA!, where relatively low-energy pulses, derived from a master oscillator, are magnified by one or more power amplifiers separated with optical isolators. Obviously, the latter configuration offers an easier power and energy con- trol, and better temporal characteristics. In general, low- cost, high-performance Q-switched fiber lasers, with a pulse energy of tens of microjoules are preferred for these applications. We present a compact Q-switched ytterbium-doped double-clad ~YDDC! fiber laser. It can stably work at a repetition rate up to 80 kHz, with the maximum pump power of 3.2 W. The pulse characteristics, such as pulse duration, buildup time, etc., are examined. Due to the self- mode-locking effect, the Q-switched pulses exhibit a mul- tipeak structure. Some researchers have previously reported the split pulses in their Q-switched fiber lasers. 6-8 Lees, and Newson observed five pulses in a Q-switched envelope of an erbium ~Er!-doped fiber laser, in which the output

Polymer-based thermo-optic waveguide beam deflector with novel dual folded-thin-strip heating electrodes

A new design scheme for a polymeric waveguide thermo- optic beam deflector is presented and experimentally demonstrated. The refractive indices of the waveguide materials can be thermally tuned by applying electric current through a metal thin film electrode deposited and patterned using standard lithography on top of the waveguide. In doing so, the geometry of the electrode determines the performance and reliability of the beam deflector. We form a pair of heating electrodes sitting opposite to each other like interlocked sawteeth that have a folded-thin-strip substructure, and hence demonstrate an advanced beam deflector that has biangular sweeping capability, low power con- sumption, less wavefront distortion, and high reliability. A full sweep angle of 56.5 mrad (3.24 deg) and 138 switching capability at a 1550 nm wavelength are attained with an average power consumption of 247 mW per switching between adjacent resolvable spots. Switching from the zero-bias spot to the first resolvable spot exhibits a response time of 2 ms in both rising and falling. © 2003 Society of Photo-Optical Instru-

Evaluation of Au to mated Aer ation Con trol in Shrimp Ponds

The fea si bil ity and en ergy ef fi ciency of man ag ing aer ation in shrimp cul ture ponds with au to mated aer a tion tech nol ogy were eval u ated. Nine 0.1-ha ponds at the Claude Peteet Mari cul ture Cen ter, Gulf Shores, Al a bama were stocked with white shrimp, Penaeus setiferus, at a rate of 42 post-lar vae/m 2. All ponds were equipped with one 1-hp (7.1 kW aer a tion/ha) as pi ra tor pump aer a tors that were ac ti vated man ually, with tim ers, or with au to mated ox y gen sens ing de vices. Au to mated aer a tion was ini ti ated when dis solved ox y gen (DO) con cen tra tion dropped be low 3.2 mg/L (45% sat u ra tion) and ter mi nated when DO con cen tra tion rose above 4.2 mg/L. Timers were pre-set to ini ti ate aer a tion af ter nightfall when DO con cen tra tion fell be low 3.2 mg/L. Man ual op er a tion of aer a tion in volved ac ti vat ing aer a tors at sun down and ter mi nat ing op er ation at about 0800. At har vest there were no sig nif i cant dif fer ences among treat ments for gross shrimp yield, mean weight or sur vival (P > 0.05). Mean power con sump tion, mea sured in ki lo watt-hours, was signif i cantly dif fer ent among treat ments (P > 0.05). Au to mated aer a tion con trol ponds used 62% less power than timer-op er ated ponds and 80% less power than man u ally op er ated ponds. Timed op er a tion of aer a tors used 42% less power than man u ally op er ated treat ments. The au to mated con trol sys tem and timer sys tem re duced power costs over man ual op era tions. The au to mated sys tem pro vided the pro ducer with real-time infor ma tion about DO and tem per a ture reg i mens. Un der more in ten sive sys tems as aer a tion needs in crease, ex pected en ergy sav ings from automated con trol would likely de crease. Ini ti a tion of aer a tion by tim ers is a good, low-cost al ter na tive to au to mated con trols but with out the ben e fits of au to mated mea sure ment and real-time view ing of DO.

A Fast Response Continuous Analyzer for Halogenated Atmospheric Tracers

Abstract A fast response version of the continuous SF6 analyzer originally introduced in 1976 has been developed. The new continuous analyzer has a response time constant of 0.36 s, which is 4–30 times faster than previous analyzers. The very fast response of the new analyzer allows it to be used to investigate the fundamental nature of atmospheric turbulence and diffusion processes. The new design has been thoroughly tested in laboratory and field conditions over an ambient temperature range from 4° to 40°C and an elevation range of 265 to 2130 m above sea level. The reproducibility in the response of the new analyzer was approximately ±15% over a one-month period. In automobile and aircraft sampling platforms, the reproducibility in response was less than ±12% for periods as long as 7.5 h and elevation changes exceeding 1800 m. The rate of baseline change was <1 ppt min−1 in the laboratory, <10 ppt min−1 in an automobile platform, and 15 ppt min−1 in an aircraft platform. The size, weight, and power con...

Theory for Hinged Wavemakers of Finite Draft in Water of Constant Depth

Extending the theoretical work of Biesel, a study is made of a flap-type wavemaker hinged in the middle of a wall. The first-order linearized hydrodynamic equations of motion are solved to obtain the velocity potential, which is composed of a wave part and a spatially transitory part. Characteristics of generated waves far away from the wavemaker are analyzed as to the wave profile, flap stroke, water particle excursions, and power con- sumption of the wavemaker. The importance of the spatially transitory part is discussed with regard to the role played by the inertia pressure, which gives rise to added inertia of the flap. Surface elevations very near the flap are found. The hydrodynamically induced torque and the total hydrodynamic force on the flap are computed. The computed results seem to be well explained by the differing behaviors of the normal pressure and of the iner- tia pressure with increasing water depth. HE theoretical foundation of laboratory wave- generating apparatus was developed in detail by Biesel 1 and coworkers of Grenoble, pertaining to two-dimension al irrotational motions in prismatic channels of rectangular cross-section. Following the classical wavemaker theory of Havelock, Biesel solved the first-order linearized hydrodynamic equations of motion to find the resultant wave motions caused by a wavemaker at one end of a channel. As examples, he considered two simple cases, namely, a piston- type wavemaker, and a flap-type wavemaker hinged at the bottom of a wall. A brief comparison was made of the two types of wavemaker with regard to the quality of generated waves, wavemaker stroke, and the total hydrodynamic force applied at the wavemaker. The validity of the first-order wavemaker theory was experimentally verified by Ursell, Dean, and Yu,2 with particular reference to a piston-type wavemaker. For all practical purposes, however, flap-type wavemakers in common use today are fabricated with their lower ends hinged in the middle of the wall, unlike the simple flap-type wavemaker investigated by Biesel.'An article by Taniguchi and Shibata3 reported that agreement was satisfactory bet- ween the predictions of the first-order wavemaker theory and the measurements conducted in the Mitsubishi Nagasaki ex- perimental tank. The Nagasaki tank was equipped with a flap- type wavemaker, whose flap draft (the distance from the un- disturbed mean water surface to the lower hinges of the flap) was 1.77 m, and the constant water depth was 6.31 m. Their measurements dealt with flap frequency, flap stroke, wave profile, and the reaction force at the piston rod of the hydraulic drive. As was pointed out by Taniguchi and Shibata, published theses on wavemakers are rather scarce, and few scattered technical data for wavemaker performance are available in the literature. In most descriptive reports of existing towing tank facilities,4'5'6 wavemakers seem to be somewhat cursorily treated without providing much technical information. A unified account of a flap-type wavemaker, including detailed analysis of the added inertia effect of the flap, which was not previously discussed, is presented here. Relevant theoretical considerations, based on the first-order linearized hydrodynamic equations of motion, are given and possible analytical approaches are used. Treating the flap draft as a parameter, numerical computations are carried out to study the quality of generated waves and the hydrodynamically in- duced force and torque on the flap. The added inertia effect of the flap, which is a consequence of the spatially transitory part of fluid motion, is closely examined with respect to the flap torque augmentation and water particle displacements near the wavemaker. The analysis of a flap-type wavemaker is of practical usefulness in that it can be utilized for more general purposes, including the determination of the added mass and the damping coefficient of thin vertical bodies in water.