Transmit Power Optimisation in Wireless Network
Besnik Terziu
2011-09-01
Full Text Available Transmit power optimisation in wireless networks based on beamforming have emerged as a promising technique to enhance the spectrum efficiency of present and future wireless communication systems. The aim of this study is to minimise the access point power consumption in cellular networks while maintaining a targeted quality of service (QoS for the mobile terminals. In this study, the targeted quality of service is delivered to a mobile station by providing a desired level of Signal to Interference and Noise Ratio (SINR. Base-stations are coordinated across multiple cells in a multi-antenna beamforming system. This study focuses on a multi-cell multi-antenna downlink scenario where each mobile user is equipped with a single antenna, but where multiple mobile users may be active simultaneously in each cell and are separated via spatial multiplexing using beamforming. The design criteria is to minimize the total weighted transmitted power across the base-stations subject to SINR constraints at the mobile users. The main contribution of this study is to define an iterative algorithm that is capable of finding the joint optimal beamformers for all basestations, based on a correlation-based channel model, the full-correlation model. Among all correlated channel models, the correlated channel model used in this study is the most accurate, giving the best performance in terms of power consumption. The environment here in this study is chosen to be Non-Light of- Sight (NLOS condition, where a signal from a wireless transmitter passes several obstructions before arriving at a wireless receiver. Moreover there are many scatterers local to the mobile, and multiple reflections can occur among them before energy arrives at the mobile. The proposed algorithm is based on uplink-downlink duality using the Lagrangian duality theory. Time-Division Duplex (TDD is chosen as the platform for this study since it has been adopted to the latest technologies in Fourth
On the power amplifier nonlinearity in MIMO transmit beamforming systems
Qi, Jian
2012-03-01
In this paper, single-carrier multiple-input multiple-output (MIMO) transmit beamforming (TB) systems in the presence of high-power amplifier (HPA) nonlinearity are investigated. Specifically, due to the suboptimality of the conventional maximal ratio transmission/maximal ratio combining (MRT/MRC) under HPA nonlinearity, we propose the optimal TB scheme with the optimal beamforming weight vector and combining vector, for MIMO systems with nonlinear HPAs. Moreover, an alternative suboptimal but much simpler TB scheme, namely, quantized equal gain transmission (QEGT), is proposed. The latter profits from the property that the elements of the beamforming weight vector have the same constant modulus. The performance of the proposed optimal TB scheme and QEGT/MRC technique in the presence of the HPA nonlinearity is evaluated in terms of the average symbol error probability and mutual information with the Gaussian input, considering the transmission over uncorrelated quasi-static frequency-flat Rayleigh fading channels. Numerical results are provided and show the effects on the performance of several system parameters, namely, the HPA parameters, numbers of antennas, quadrature amplitude modulation modulation order, number of pilot symbols, and cardinality of the beamforming weight vector codebook for QEGT. © 2012 IEEE.
Adjacency matrix-based transmit power allocation strategies in wireless sensor networks.
Consolini, Luca; Medagliani, Paolo; Ferrari, Gianluigi
2009-01-01
In this paper, we present an innovative transmit power control scheme, based on optimization theory, for wireless sensor networks (WSNs) which use carrier sense multiple access (CSMA) with collision avoidance (CA) as medium access control (MAC) protocol. In particular, we focus on schemes where several remote nodes send data directly to a common access point (AP). Under the assumption of finite overall network transmit power and low traffic load, we derive the optimal transmit power allocation strategy that minimizes the packet error rate (PER) at the AP. This approach is based on modeling the CSMA/CA MAC protocol through a finite state machine and takes into account the network adjacency matrix, depending on the transmit power distribution and determining the network connectivity. It will be then shown that the transmit power allocation problem reduces to a convex constrained minimization problem. Our results show that, under the assumption of low traffic load, the power allocation strategy, which guarantees minimal delay, requires the maximization of network connectivity, which can be equivalently interpreted as the maximization of the number of non-zero entries of the adjacency matrix. The obtained theoretical results are confirmed by simulations for unslotted Zigbee WSNs.
Microwave power transmitting phased array antenna research project
Dickinson, R. M.
1978-01-01
An initial design study and the development results of an S band RF power transmitting phased array antenna experiment system are presented. The array was to be designed, constructed and instrumented to permit wireless power transmission technology evaluation measurements. The planned measurements were to provide data relative to the achievable performance in the state of the art of flexible surface, retrodirective arrays, as a step in technically evaluating the satellite power system concept for importing to earth, via microwave beams, the nearly continuous solar power available in geosynchronous orbit. Details of the microwave power transmitting phased array design, instrumentation approaches, system block diagrams, and measured component and breadboard characteristics achieved are presented.
Joint Transmit Beamforming and Power Control for CDMA System
LI Ji-long; CHEN Yu; LI Chun-yuan; ZHANG Ping
2005-01-01
Downlink transmit beamforming is a promising technique to reduce interference,and power control is a technique to adjust transmission power to satisfy the link quality.Joint transmission power control and beamforming are proposed to minimize total transmission power.The joint optimization problem is solved by receiver beamforming and power control in virtual uplink.SIR based power control is performed to adjust the power allocation,and transmit beamforming weight vectors are determined by Minimum Variance Distortionless Response(MVDR)criterion.The multipath combining weight vectors are determined by maximum ratio combining criterion.Simulation results show the joint optimization scheme decreases the transmission power,and system performance is enhanced.
Xi, Songnan; Zoltowski, Michael D.
2008-04-01
Multiuser multiple-input multiple-output (MIMO) systems are considered in this paper. We continue our research on uplink transmit beamforming design for multiple users under the assumption that the full multiuser channel state information, which is the collection of the channel state information between each of the users and the base station, is known not only to the receiver but also to all the transmitters. We propose an algorithm for designing optimal beamforming weights in terms of maximizing the signal-to-interference-plus-noise ratio (SINR). Through statistical modeling, we decouple the original mathematically intractable optimization problem and achieved a closed-form solution. As in our previous work, the minimum mean-squared error (MMSE) receiver with successive interference cancellation (SIC) is adopted for multiuser detection. The proposed scheme is compared with an existing jointly optimized transceiver design, referred to as the joint transceiver in this paper, and our previously proposed eigen-beamforming algorithm. Simulation results demonstrate that our algorithm, with much less computational burden, accomplishes almost the same performance as the joint transceiver for spatially independent MIMO channel and even better performance for spatially correlated MIMO channels. And it always works better than our previously proposed eigen beamforming algorithm.
Maximally Flat Waveforms Operation of Class-F Power Amplifiers
V. Krizhanovski
2001-04-01
Full Text Available The requirements to output network's impedance on higher harmoniccomponents and appropriate input driving for formation maximally flatwaveforms of drain current and voltage were presented. Using suchwaveforms allows obtaining maximal efficiency and output powercapability of class-F power amplifiers.
Transmit power optimization for green multihop relaying over Nakagami-m fading channels
Randrianantenaina, Itsikiantsoa
2014-03-01
In this paper, we investigate the optimal transmit power strategy to maximize the energy efficiency of a multihop relaying network. Considering the communication between a source and a destination through multiple Amplify-and-Forward relays, we first give the expression of the total instantaneous system energy consumption. Then, we define the energy efficiency in our context and obtain its expression in closed-form when the communication is over Nakagami-m fading channels. The analysis yields to the derivation of a global transmit power strategy where each individual node is contributing to the end-to-end overall energy efficiency. Numercial results are presented to illustrate the analysis. Comparison with Monte Carlo simulation results confirms the accuracy of our derivations, and assesses the gains of the proposed power optimization strategy. © 2014 IEEE.
Carnot cycle at finite power: attainability of maximal efficiency.
Allahverdyan, Armen E; Hovhannisyan, Karen V; Melkikh, Alexey V; Gevorkian, Sasun G
2013-08-01
We want to understand whether and to what extent the maximal (Carnot) efficiency for heat engines can be reached at a finite power. To this end we generalize the Carnot cycle so that it is not restricted to slow processes. We show that for realistic (i.e., not purposefully designed) engine-bath interactions, the work-optimal engine performing the generalized cycle close to the maximal efficiency has a long cycle time and hence vanishing power. This aspect is shown to relate to the theory of computational complexity. A physical manifestation of the same effect is Levinthal's paradox in the protein folding problem. The resolution of this paradox for realistic proteins allows to construct engines that can extract at a finite power 40% of the maximally possible work reaching 90% of the maximal efficiency. For purposefully designed engine-bath interactions, the Carnot efficiency is achievable at a large power.
The Control of Transmitted Power in an Active Isolation System
Elliott, S.J.; Gardonio, P.; Pinnington, R.J.
1997-01-01
The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure and distr...... of such an active vibration control system are also discussed.......The isolation of vibration through a system with multiple active mounts is discussed, in which each of the mounts can transmit vibration in several degrees of freedom. Theoretical models of the various parts of this system have been developed which include a flexible receiving structure...... and distributed active mounts, and these models can be connected together to produce an overall theoretical description of a realistic active isolation system. Total transmitted power has been found to be an excellent criterion to quantify the effect of various control strategies in this model in which...
Transmitting electric power system dynamics in SCADA using polynomial fitting
无
2009-01-01
The paper proposes an approach to transmit electric power system dynamics in the SCADA. With the prevalent application of digital substation automation system, it is feasible for the remote terminal units (RTUs) to collect phasors within a substation. However, limited communication capacity remains the bottleneck that prevents SCADA from transmitting system dynamics. This paper proposes to compress dynamics data with curve fitting in the RTUs and reconstruct the dynamics in the SCADA server for reducing communication demand. Dispatchers in the control center can thus get system dynamics with a delay of several seconds. Simulation result shows that for a power system under disturbance with short-circuit that once occurred and was cleared, the SCADA can approximate the original dynamics with satisfying precision using limited degree polynomial fitting. The approach is highly scalable and adaptable, and can be implemented on existing communication infrastructure with a few software modifications. The approach has extensive application potential.
Lee, Jong-Ho; Sohn, Illsoo; Kim, Yong-Hwa
2016-10-17
In this paper, we consider a transmit power allocation problem for secure transmission in multi-hop decode-and-forward (DF) full-duplex relay (FDR) networks, where multiple FDRs are located at each hop and perform cooperative beamforming to null out the signal at multiple eavesdroppers. For a perfect self-interference cancellation (PSIC) case, where the self-interference signal at each FDR is completely canceled, we derive an optimal power allocation (OPA) strategy using the Karush-Kuhn-Tucker (KKT) conditions to maximize the achievable secrecy rate under an overall transmit power constraint. In the case where residual self-interferences exist owing to imperfect self-interference cancellation (ISIC), we also propose a transmit power allocation scheme using the geometric programming (GP) method. Numerical results are presented to verify the secrecy rate performance of the proposed power allocation schemes.
Jong-Ho Lee
2016-10-01
Full Text Available In this paper, we consider a transmit power allocation problem for secure transmission in multi-hop decode-and-forward (DF full-duplex relay (FDR networks, where multiple FDRs are located at each hop and perform cooperative beamforming to null out the signal at multiple eavesdroppers. For a perfect self-interference cancellation (PSIC case, where the self-interference signal at each FDR is completely canceled, we derive an optimal power allocation (OPA strategy using the Karush-Kuhn-Tucker (KKT conditions to maximize the achievable secrecy rate under an overall transmit power constraint. In the case where residual self-interferences exist owing to imperfect self-interference cancellation (ISIC, we also propose a transmit power allocation scheme using the geometric programming (GP method. Numerical results are presented to verify the secrecy rate performance of the proposed power allocation schemes.
Using Piezoelectric Devices to Transmit Power through Walls
Sherrit, Stewart; Bar-Cohen, Yoseph; Bao, Xiaoqi
2008-01-01
A method denoted wireless acoustic-electric feed-through (WAEF) has been conceived for transmitting power and/or data signals through walls or other solid objects made of a variety of elastic materials that could be electrically conductive or nonconductive. WAEF would make it unnecessary to use wires, optical fibers, tubes, or other discrete wall-penetrating signal-transmitting components, thereby eliminating the potential for structural weakening or leakage at such penetrations. Avoidance of such penetrations could be essential in some applications in which maintenance of pressure, vacuum, or chemical or biological isolation is required. In a basic WAEF setup, a transmitting piezoelectric transducer on one side of a wall would be driven at resonance to excite ultrasonic vibrations in the wall. A receiving piezoelectric transducer on the opposite side of the wall would convert the vibrations back to an ultrasonic AC electric signal, which would then be detected and otherwise processed in a manner that would depend on the modulation (if any) applied to the signal and whether the signal was used to transmit power, data, or both. An electromechanical-network model has been derived as a computationally efficient means of analyzing and designing a WAEF system. This model is a variant of a prior model, known in the piezoelectric-transducer art as Mason's equivalent-circuit model, in which the electrical and mechanical dynamics, including electromechanical couplings, are expressed as electrical circuit elements that can include inductors, capacitors, and lumped-parameter complex impedances. The real parts of the complex impedances are used to account for dielectric, mechanical, and coupling losses in all components (including all piezoelectric-transducer, wall, and intermediate material layers). In an application to a three-layer piezoelectric structure, this model was shown to yield the same results as do solutions of the wave equations of piezoelectricity and acoustic
LOAD THAT MAXIMIZES POWER OUTPUT IN COUNTERMOVEMENT JUMP
Pedro Jimenez-Reyes
2016-02-01
Full Text Available ABSTRACT Introduction: One of the main problems faced by strength and conditioning coaches is the issue of how to objectively quantify and monitor the actual training load undertaken by athletes in order to maximize performance. It is well known that performance of explosive sports activities is largely determined by mechanical power. Objective: This study analysed the height at which maximal power output is generated and the corresponding load with which is achieved in a group of male-trained track and field athletes in the test of countermovement jump (CMJ with extra loads (CMJEL. Methods: Fifty national level male athletes in sprinting and jumping performed a CMJ test with increasing loads up to a height of 16 cm. The relative load that maximized the mechanical power output (Pmax was determined using a force platform and lineal encoder synchronization and estimating the power by peak power, average power and flight time in CMJ. Results: The load at which the power output no longer existed was at a height of 19.9 ± 2.35, referring to a 99.1 ± 1% of the maximum power output. The load that maximizes power output in all cases has been the load with which an athlete jump a height of approximately 20 cm. Conclusion: These results highlight the importance of considering the height achieved in CMJ with extra load instead of power because maximum power is always attained with the same height. We advise for the preferential use of the height achieved in CMJEL test, since it seems to be a valid indicative of an individual's actual neuromuscular potential providing a valid information for coaches and trainers when assessing the performance status of our athletes and to quantify and monitor training loads, measuring only the height of the jump in the exercise of CMJEL.
Selecting a Subset of Stimulus-Response Pairs with Maximal Transmitted Information
1992-03-01
more? ( Kantowitz and Sorkin, 1983, 309-317) The last question implies a transfer of information from the lever to the pilot. In fact, if there were...of information transmitted by all S-R pairs in the matrix can be calculated using information theory and basic set theory ( Kantowitz and Sorkin, 1983...Garner (1962). Additional notation and theory comes from Kantowitz and Sorkin (1983). 1. Information Theory Background Information theory is derived
Integral circulant graphs of prime power order with maximal energy
Sander, Jürgen W; 10.1016/j.laa.2011.05.039
2011-01-01
The energy of a graph is the sum of the moduli of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count n and a set D of divisors of n in such a way that they have vertex set Zn and edge set {{a, b} : a, b in Zn; gcd(a - b, n) in D}. Using tools from convex optimization, we study the maximal energy among all integral circulant graphs of prime power order ps and varying divisor sets D. Our main result states that this maximal energy approximately lies between s(p - 1)p^(s-1) and twice this value. We construct suitable divisor sets for which the energy lies in this interval. We also characterize hyperenergetic integral circulant graphs of prime power order and exhibit an interesting topological property of their divisor sets.
Energy Efficiency Maximization for WSNs with Simultaneous Wireless Information and Power Transfer.
Yu, Hongyan; Zhang, Yongqiang; Guo, Songtao; Yang, Yuanyuan; Ji, Luyue
2017-08-18
Recently, the simultaneous wireless information and power transfer (SWIPT) technique has been regarded as a promising approach to enhance performance of wireless sensor networks with limited energy supply. However, from a green communication perspective, energy efficiency optimization for SWIPT system design has not been investigated in Wireless Rechargeable Sensor Networks (WRSNs). In this paper, we consider the tradeoffs between energy efficiency and three factors including spectral efficiency, the transmit power and outage target rate for two different modes, i.e., power splitting (PS) and time switching modes (TS), at the receiver. Moreover, we formulate the energy efficiency maximization problem subject to the constraints of minimum Quality of Service (QoS), minimum harvested energy and maximum transmission power as non-convex optimization problem. In particular, we focus on optimizing power control and power allocation policy in PS and TS modes to maximize energy efficiency of data transmission. For PS and TS modes, we propose the corresponding algorithm to characterize a non-convex optimization problem that takes into account the circuit power consumption and the harvested energy. By exploiting nonlinear fractional programming and Lagrangian dual decomposition, we propose suboptimal iterative algorithms to obtain the solutions of non-convex optimization problems. Furthermore, we derive the outage probability and effective throughput from the scenarios that the transmitter does not or partially know the channel state information (CSI) of the receiver. Simulation results illustrate that the proposed optimal iterative algorithm can achieve optimal solutions within a small number of iterations and various tradeoffs between energy efficiency and spectral efficiency, transmit power and outage target rate, respectively.
Yanjie Dong
2013-01-01
Full Text Available The capacity of Multiple Input Multiple Output (MIMO system is highly related to the number of active antennas. But as the active antenna number increases, the MIMO system will consume more energy. To maximize the energy efficiency of MIMO system, we propose an antenna selection scheme which can maximize the energy efficiency of BS cluster. In the scheme, ergodic energy efficiency is derived according to large scale channel state information (CSI. Based on this ergodic energy efficiency, we introduce a cost function varied with the number of antennas, in which the effect to the energy efficiency of both the serving BS and the neighbor BS is considered. With this function, we can transform the whole system optimization problem to a sectional optimization problem and obtain a suboptimal antenna set using a heuristic algorithm. Simulation results verify that the proposed approach performs better than the comparison schemes in terms of network energy efficiency and achieves 98% network energy efficiency of the centralized antenna selection scheme. Besides, since the proposed scheme does not need the complete CSI of the neighbor BS, it can effectively reduce the signaling overhead.
Discussion on: "Profit maximization of a power plant"
Boomsma, Trine Krogh; Fleten, Stein-Erik
2012-01-01
Kragelund et al. provides an interesting contribution to operations scheduling in liberalized electricity markets. They address the problem of profit maximization for a power plant participating in the electricity market. In particular, given that the plant has already been dispatched in a day......-ahead market, the aim is to schedule production throughout an operation day while complying with the day-ahead commitments, referred to in the paper as tracking a predefined production reference. The authors refer to Fig. 2 for an example of a production reference plan for a power plant of DONG Energy. A minor...... with the balancing mechanisms in most electricity markets, since no (or only very small) deviations are acceptable....
A cycle ergometer test of maximal aerobic power.
Myles, W S; Toft, R J
1982-01-01
An indirect test of maximal aerobic power (IMAP) was evaluated in 31 healthy male subjects by comparing it with a direct treadmill measurement of maximal aerobic power (VO2 max), with the prediction of VO2 max from heart rate during submaximal exercise on a cycle ergometer using Astrand's nomogram, with the British Army's Basic Fitness Test (BFT, a 2.4 km run performed in boots and trousers), and with a test of maximum anaerobic power. For the IMAP test, subjects pedalled on a cycle ergometer at 75 revs X min-1. The workload was 37.5 watts for the first minute, and was increased by 37.5 watts every minute until the subject could not continue. Time to exhaustion was recorded. Predicted VO2 max and times for BFT and IMAP correlated significantly (p less than 0.001) with the direct VO2 max: r = 0.70, r = 0.67 and r = 0.79 respectively. The correlation between direct VO2 max and the maximum anaerobic power test was significant (p less than 0.05) but lower, r = 0.44. Although lactate levels after direct VO2 max determination were significantly higher than those after the IMAP test, maximum heart rates were not significantly different. Submaximal VO2 values measured during the IMAP test yielded a regression equation relating VO2 and pedalling time. When individual values for direct and predicted VO2 max and times for BFT and IMAP were compared with equivalent standards, the percentages of subjects able to exceed the standard were 100, 65, 87, and 87 respectively. These data demonstrate that the IMAP test provides a valid estimate of VO2 max and indicate that it may be a practical test for establishing that an individual meets a minimum standard.
Lee, Joong Seok; Lee, Il Kyu; Seung, Hong Min; Lee, Jun Kyu; Kim, Yoon Young
2017-03-01
Joints with slowly varying tapered shapes, such as linear or exponential profiles, are known to transmit incident wave power efficiently between two waveguides with dissimilar impedances. This statement is valid only when the considered joint length is longer than the wavelengths of the incident waves. When the joint length is shorter than the wavelengths, however, appropriate shapes of such subwavelength joints for efficient power transmission have not been explored much. In this work, considering one-dimensional torsional wave motion in a cylindrical elastic waveguide system, optimal shapes or radial profiles of a subwavelength joint maximizing the power transmission coefficient are designed by a gradient-based optimization formulation. The joint is divided into a number of thin disk elements using the transfer matrix approach and optimal radii of the disks are determined by iterative shape optimization processes for several single or bands of wavenumbers. Due to the subwavelength constraint, the optimized joint profiles were found to be considerably different from the slowly varying tapered shapes. Specifically, for bands of wavenumbers, peculiar gourd-like shapes were obtained as optimal shapes to maximize the power transmission coefficient. Numerical results from the proposed optimization formulation were also experimentally realized to verify the validity of the present designs.
Maximizing Statistical Power When Verifying Probabilistic Forecasts of Hydrometeorological Events
DeChant, C. M.; Moradkhani, H.
2014-12-01
Hydrometeorological events (i.e. floods, droughts, precipitation) are increasingly being forecasted probabilistically, owing to the uncertainties in the underlying causes of the phenomenon. In these forecasts, the probability of the event, over some lead time, is estimated based on some model simulations or predictive indicators. By issuing probabilistic forecasts, agencies may communicate the uncertainty in the event occurring. Assuming that the assigned probability of the event is correct, which is referred to as a reliable forecast, the end user may perform some risk management based on the potential damages resulting from the event. Alternatively, an unreliable forecast may give false impressions of the actual risk, leading to improper decision making when protecting resources from extreme events. Due to this requisite for reliable forecasts to perform effective risk management, this study takes a renewed look at reliability assessment in event forecasts. Illustrative experiments will be presented, showing deficiencies in the commonly available approaches (Brier Score, Reliability Diagram). Overall, it is shown that the conventional reliability assessment techniques do not maximize the ability to distinguish between a reliable and unreliable forecast. In this regard, a theoretical formulation of the probabilistic event forecast verification framework will be presented. From this analysis, hypothesis testing with the Poisson-Binomial distribution is the most exact model available for the verification framework, and therefore maximizes one's ability to distinguish between a reliable and unreliable forecast. Application of this verification system was also examined within a real forecasting case study, highlighting the additional statistical power provided with the use of the Poisson-Binomial distribution.
Hyuck-Min Kweon
2014-12-01
Full Text Available To maximize electric power production using wave energy extractions from resonance power buoys, the maximum motion displacement spectra of the buoys can primarily be obtained under a given wave condition. In this study, wave spectra observed in shoaling water were formulated. Target resonance frequencies were established from the arithmetic means of modal frequency bands and the peak frequencies. The motion characteristics of the circular cylindrical power buoys with corresponding drafts were then calculated using numerical models without considering PTO damping force. Results showed that the heave motions of the power buoys in shoaling waters with insufficient drafts produced greater amplification effects than those in deep seas with sufficient drafts.
Mitochondrial filaments and clusters as intracellular power-transmitting cables.
Skulachev, V P
2001-01-01
Mitochondria exist in two interconverting forms; as small isolated particles, and as extended filaments, networks or clusters connected with intermitochondrial junctions. Extended mitochondria can represent electrically united systems, which can facilitate energy delivery from the cell periphery to the cell core and organize antioxidant defence of the cell interior when O2 is consumed by mitochondrial clusters near the the outer cell membrane, and protonic potential is transmitted to the cell core mitochondria to form ATP. As to small mitochondria, they might represent a transportable form of these organelles.
Yang, Guangye; Jia, Suotang; Mihalache, Dumitru
2013-01-01
We address the possibility to control high power pulses extracted from the maximally compressed pulse in a nonlinear optical fiber by adjusting the initial excitation parameters. The numerical results show that the power, location and splitting order number of the maximally compressed pulse and the transmission features of high power pulses extracted from the maximally compressed pulse can be manipulated through adjusting the modulation amplitude, width, and phase of the initial Gaussian-type perturbation pulse on a continuous wave background.
Ke, Quan; Luo, Weijie; Yan, Guozheng; Yang, Kai
2016-04-01
A wireless power transfer system based on the weakly inductive coupling makes it possible to provide the endoscope microrobot (EMR) with infinite power. To facilitate the patients' inspection with the EMR system, the diameter of the transmitting coil is enlarged to 69 cm. Due to the large transmitting range, a high quality factor of the Litz-wire transmitting coil is a necessity to ensure the intensity of magnetic field generated efficiently. Thus, this paper builds an analytical model of the transmitting coil, and then, optimizes the parameters of the coil by enlarging the quality factor. The lumped model of the transmitting coil includes three parameters: ac resistance, self-inductance, and stray capacitance. Based on the exact two-dimension solution, the accurate analytical expression of ac resistance is derived. Several transmitting coils of different specifications are utilized to verify this analytical expression, being in good agreements with the measured results except the coils with a large number of strands. Then, the quality factor of transmitting coils can be well predicted with the available analytical expressions of self- inductance and stray capacitance. Owing to the exact estimation of quality factor, the appropriate coil turns of the transmitting coil is set to 18-40 within the restrictions of transmitting circuit and human tissue issues. To supply enough energy for the next generation of the EMR equipped with a Ø9.5×10.1 mm receiving coil, the coil turns of the transmitting coil is optimally set to 28, which can transfer a maximum power of 750 mW with the remarkable delivering efficiency of 3.55%.
47 CFR 90.542 - Broadband transmitting power limits.
2010-10-01
...)(5) of this section, the power flux density that would be produced by such stations through a...) Fixed and base stations located in a county with population density of 100 or fewer persons per square... with population density of 100 or fewer persons per square mile, based upon the most recently...
Time of day has no effect on maximal aerobic and peak power
Sesboüé B
2011-08-01
Full Text Available N Bessot1,3, S Moussay1,2, B Dufour1,2, D Davenne1,2, B Sesboüé1,3, A Gauthier1,21Inserm, ERI27, Caen, France; 2University Caen, Caen, France; 3CHRU Caen, Explorations Fonctionnelles, Caen, FranceBackground: The aim of this study was to explore the effect of time of day on peak power reached during an exercise test and maximal aerobic power achieved when the subject reached maximal oxygen uptake.Methods: Fifteen male competitive endurance cyclists performed a standardized maximal incremental exercise test at 06:00 hours and 18:00 hours. The test began with a 5-minute warmup period at a workload of 150 W. The work rate was then increased by incremental steps of 30 W per minute until the respiratory exchange ratio reached 1.00. Thereafter, workload was increased in steps of 15 W per minute until exhaustion was reached.Results: No significant diurnal variation was detected in physiological parameters (maximal oxygen uptake and maximal heart rate or biomechanical parameters (maximal aerobic power, peak power.Conclusion: Circadian variations classically reported in competitive aerobic performances could be due to fluctuations in maximal aerobic endurance and/or improvement in gestural efficiency (pattern of muscle activity, effective force production, and kinematics.Keywords: chronobiology, maximal aerobic power, peak power, maximal oxygen uptake, maximal incremental test
Buelna, Christina; Ulloa, Emilio C.; Ulibarri, Monica D.
2009-01-01
This study examined relationship power as a possible mediator of the relationship between dating violence and sexually transmitted infections (STIs). The proposed mediation model was based on the theory of gender and power as well as previous research on intimate partner violence and STI risk. Survey results from a sample of 290 single,…
Mohsen Taherbaneh; A. H. Rezaie; H. Ghafoorifard; Rahimi, K; M. B. Menhaj
2010-01-01
In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar...
Inter-Vehicle Communication System Utilizing Autonomous Distributed Transmit Power Control
Hamada, Yuji; Sawa, Yoshitsugu; Goto, Yukio; Kumazawa, Hiroyuki
In ad-hoc network such as inter-vehicle communication (IVC) system, safety applications that vehicles broadcast the information such as car velocity, position and so on periodically are considered. In these applications, if there are many vehicles broadcast data in a communication area, congestion incurs a problem decreasing communication reliability. We propose autonomous distributed transmit power control method to keep high communication reliability. In this method, each vehicle controls its transmit power using feed back control. Furthermore, we design a communication protocol to realize the proposed method, and we evaluate the effectiveness of proposed method using computer simulation.
Maximally Flat Waveforms with Finite Number of Harmonics in Class-F Power Amplifiers
Anamarija Juhas
2013-01-01
Full Text Available In this paper general solution to the problem of finding maximally flat waveforms with finite number of harmonics (maximally flat trigonometric polynomials is provided. Waveform coefficients are expressed in closed form as functions of harmonic orders. Two special cases of maximally flat waveforms (so-called maximally flat even harmonic and maximally flat odd harmonic waveforms, which proved to play an important role in class-F and inverse class-F power amplifier (PA operations, are also considered. For these two special types of waveforms, coefficients are expressed as functions of two parameters only. Closed form expressions for efficiency and power output capability of class-F and inverse class-F PA operations with maximally flat waveforms are also provided as explicit functions of number of a harmonics.
Impact of sensing errors on the queueing delay and transmit power in cognitive radio access
Hamza, Doha R.
2011-03-01
We study a multiple-access system with a primary user (PU) and a secondary user (SU) utilizing the same frequency band and communicating with a common receiver. Both users transmit with a fixed transmission rate by employing a channel inversion power control scheme. The SU transmits with a certain probability that depends on the sensing outcome, its queue length and whether it has a new packet arrival. We consider the case of erroneous sensing. The goal of the SU is to find the optimal transmission scheduling policy so as to minimize its queueing delay under constraints on its average transmit power and the maximum tolerable primary outage probability caused by miss-detection. The access probabilities are obtained efficiently using linear programming. © 2011 IEEE.
Norhisam Misron
2016-08-01
Full Text Available A new control estimator to maximize the power generated with a maximum power point estimator is introduced. The power mapping characteristics from the double-stator generator are modeled as a mathematical equation which is used to develop the estimator for maximum power tracking to maximize the generated power. The proposed estimator automatically traces the instantaneous maximum power at various load conditions. However, to stabilize the output voltage, a boost converter is used from the inverter side. The developed double-stator generator is tested with the new estimator for the maximizing power generation capability under laboratory conditions. The experimental results confirm that with the new estimator, the average power generation capability is increased by 12% and the peak value is increase by 22%.
Low complexity transmit antenna selection with power balancing in OFDM systems
Park, Kihong
2010-10-01
In this paper, we consider multi-carrier systems with multiple transmit antennas under the power balancing constraint, which is defined as the constraint that the power on each antenna should be limited under a certain level due to the linearity of the power amplifier of the RF chain. Applying transmit antenna selection and fixed-power variable-rate transmission per subcarrier as a function of channel variations, we propose an implementation-friendly antenna selection method which offers a reduced complexity in comparison with the optimal antenna selection scheme. More specifically, in order to solve the subcarrier imbalance across the antennas, we operate a two-step reallocation procedure to minimize the loss of spectral efficiency. We also provide an analytic lower bound on the spectral efficiency for the proposed scheme. From selected numerical results, we show that our suboptimal scheme offers almost the same spectral efficiency as the optimal one. © 2010 IEEE.
Solo Power: How One-Person Librarians Maximize Their Influence.
St. Clair, Guy
1997-01-01
One person librarians or solo librarians are the information providers of the future. This article discusses the need for solo librarians to be concerned with power and influence; service to customers; and political awareness/shared vision/partnership with management. Sidebar contains the OPL (One-Person Library) Manifesto with fundamental…
Sliding Mode Control Strategy for Wind Turbine Power Maximization
Oscar Barambones
2012-07-01
Full Text Available The efficiency of the wind power conversions systems can be greatly improved using an appropriate control algorithm. In this work, a sliding mode control for variable speed wind turbine that incorporates a doubly fed induction generator is described. The electrical system incorporates a wound rotor induction machine with back-to-back three phase power converter bridges between its rotor and the grid. In the presented design the so-called vector control theory is applied, in order to simplify the electrical equations. The proposed control scheme uses stator flux-oriented vector control for the rotor side converter bridge control and grid voltage vector control for the grid side converter bridge control. The stability analysis of the proposed sliding mode controller under disturbances and parameter uncertainties is provided using the Lyapunov stability theory. Finally simulated results show, on the one hand, that the proposed controller provides high-performance dynamic characteristics, and on the other hand, that this scheme is robust with respect to the uncertainties that usually appear in the real systems.
Polymer-composite fibers for transmitting high peak power pulses at 1.55 microns.
Ruff, Zachary; Shemuly, Dana; Peng, Xiang; Shapira, Ofer; Wang, Zheng; Fink, Yoel
2010-07-19
Hollow-core photonic bandgap fibers (PBG) offer the opportunity to suppress highly the optical absorption and nonlinearities of their constituent materials, which makes them viable candidates for transmitting high-peak power pulses. We report the fabrication and characterization of polymer-composite PBG fibers in a novel materials system, polycarbonate and arsenic sulfide glass. Propagation losses for the 60 microm-core fibers are less than 2dB/m, a 52x improvement over previous 1D-PBG fibers at this wavelength. Through preferential coupling the fiber is capable of operating with over 97% the fiber's power output in the fundamental (HE(11)) mode. The fiber transmitted pulses with peak powers of 11.4 MW before failure.
Lingwei Xu
2016-02-01
Full Text Available The outage probability (OP performance of multiple-relay incremental-selective decode-and-forward (ISDF relaying mobile-to-mobile (M2M sensor networks with transmit antenna selection (TAS over N-Nakagami fading channels is investigated. Exact closed-form OP expressions for both optimal and suboptimal TAS schemes are derived. The power allocation problem is formulated to determine the optimal division of transmit power between the broadcast and relay phases. The OP performance under different conditions is evaluated via numerical simulation to verify the analysis. These results show that the optimal TAS scheme has better OP performance than the suboptimal scheme. Further, the power allocation parameter has a significant influence on the OP performance.
Koten, V. K.; Tanamal, C. E.
2017-03-01
Manufacturing agricultural products by the farmers, people or person who involve in medium industry, small industry, and households industry still be done in separately. Although the power on primemover is enough, in operations, primemover was only to move one of several agricultural products machine. This study attempts to design and construct power transmition multi output with single primemover; a single construction that allows primemover move some agricultur products machine in the same or not. This study begins with the determination of production capacity and the power to destroy products, the determination of resources and rotation, normalization of resources and rotation, the determination of the type material used, the size determination of each machine elements, construction machine elements, and assemble machine elements into a construction multi output power transmition with single primemover on agricultural products machine. The results show that with a input normalization 4 PK (2984 Watt), rotation 2000 rpm, the strength of material 60 kg/mm2, and several operating consideration, thus obtained size of machine elements through calculation. Based on the size, the machine elements is made through the use of some machine tools and assembled to form a multi output power transmition with single primemover.
Maximizing MST's inductive capability with a Bp programmable power supply
Chapman, B. E.; Holly, D. J.; Jacobson, C. M.; McCollam, K. J.; Morin, J. C.; Sarff, J. S.; Squitieri, A.
2016-10-01
A major goal of the MST program is the advancement of inductive control for the development of both the RFP's fusion potential and, synergistically, the predictive capability of fusion science. This entails programmable power supplies (PPS's) for the Bt and Bp circuits. A Bt PPS is already in place, allowing advanced RFP operation and the production of tokamak plasmas, and a Bp PPS prototype is under construction. To explore some of the new capabilities to be provided by the Bp PPS, the existing Bt PPS has been temporarily connected to the Bp circuit. One key result is new-found access to very low Ip (20 kA) and very low Lundquist number, S (104). At this low S, simulation of RFP plasmas with the MHD code NIMROD is readily achievable, and work toward validation of extended MHD models using NIMROD is underway with direct comparisons to these MST plasmas. The full Bp PPS will also provide higher Ip and S than presently possible, allowing MST to produce plasmas with S spanning as much as five orders of magnitude, a dramatic extension of MST's capability. In these initial tests, the PPS has also increased five-fold MST's Ip flattop duration, to about 100 ms. This, coupled with the recently demonstrated PPS ability to drive large-amplitude sinusoidal oscillations in Ip, will allow tests of extended-duration oscillating field current drive, the goal of which is ac sustainment of a quasi-dc plasma current. Work supported by US DOE.
Power maximization for pyroelectric, piezoelectric, and hybrid energy harvesting
Shaheen, Murtadha A.
The goal of this dissertation consists of improving the efficiency of energy harvesting using pyroelectric and piezoelectric materials in a system by the proper characterization of electrical parameters, widening frequency, and coupling of both effects with the appropriate parameters. A new simple stand-alone method of characterizing the impedance of a pyroelectric cell has been demonstrated. This method utilizes a Pyroelectric single pole low pass filter technique, PSLPF. Utilizing the properties of a PSLPF, where a known input voltage is applied and capacitance C p and resistance Rp can be calculated at a frequency of 1 mHz to 1 Hz. This method demonstrates that for pyroelectric materials the impedance depends on two major factors: average working temperature, and the heating rate. Design and implementation of a hybrid approach using multiple piezoelectric cantilevers is presented. This is done to achieve mechanical and electrical tuning, along with bandwidth widening. In addition, a hybrid tuning technique with an improved adjusting capacitor method was applied. An toroid inductor of 700 mH is shunted in to the load resistance and shunt capacitance. Results show an extended frequency range up to 12 resonance frequencies (300% improvement) with improved power up to 197%. Finally, a hybrid piezoelectric and pyroelectric system is designed and tested. Using a voltage doubler, circuit for rectifying and collecting pyroelectric and piezoelectric voltages individually is proposed. The investigation showed that the hybrid energy is possible using the voltage doubler circuit from two independent sources for pyroelectrictity and piezoelectricity due to marked differences of optimal performance.
Accounting for complementarity to maximize monitoring power for species management.
Tulloch, Ayesha I T; Chadès, Iadine; Possingham, Hugh P
2013-10-01
To choose among conservation actions that may benefit many species, managers need to monitor the consequences of those actions. Decisions about which species to monitor from a suite of different species being managed are hindered by natural variability in populations and uncertainty in several factors: the ability of the monitoring to detect a change, the likelihood of the management action being successful for a species, and how representative species are of one another. However, the literature provides little guidance about how to account for these uncertainties when deciding which species to monitor to determine whether the management actions are delivering outcomes. We devised an approach that applies decision science and selects the best complementary suite of species to monitor to meet specific conservation objectives. We created an index for indicator selection that accounts for the likelihood of successfully detecting a real trend due to a management action and whether that signal provides information about other species. We illustrated the benefit of our approach by analyzing a monitoring program for invasive predator management aimed at recovering 14 native Australian mammals of conservation concern. Our method selected the species that provided more monitoring power at lower cost relative to the current strategy and traditional approaches that consider only a subset of the important considerations. Our benefit function accounted for natural variability in species growth rates, uncertainty in the responses of species to the prescribed action, and how well species represent others. Monitoring programs that ignore uncertainty, likelihood of detecting change, and complementarity between species will be more costly and less efficient and may waste funding that could otherwise be used for management. © 2013 Society for Conservation Biology.
Power maximization of a point absorber wave energy converter using improved model predictive control
Milani, Farideh; Moghaddam, Reihaneh Kardehi
2017-08-01
This paper considers controlling and maximizing the absorbed power of wave energy converters for irregular waves. With respect to physical constraints of the system, a model predictive control is applied. Irregular waves' behavior is predicted by Kalman filter method. Owing to the great influence of controller parameters on the absorbed power, these parameters are optimized by imperialist competitive algorithm. The results illustrate the method's efficiency in maximizing the extracted power in the presence of unknown excitation force which should be predicted by Kalman filter.
Power Utility Maximization in an Exponential Lévy Model Without a Risk-free Asset
Qing Zhou
2005-01-01
We consider the problem of maximizing the expected power utility from terminal wealth in a market where logarithmic securities prices follow a Levy process. By Girsanov's theorem, we give explicit solutions for power utility of undiscounted terminal wealth in terms of the Levy-Khintchine triplet.
Ferraro, Rafael, E-mail: ferraro@iafe.uba.a [Instituto de AstronomIa y Fisica del Espacio, Casilla de Correo 67, Sucursal 28, 1428 Buenos Aires (Argentina); Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon I, 1428 Buenos Aires (Argentina)
2010-05-14
In Born-Infeld theory and other nonlinear electrodynamics, the presence of a magnetostatic field modifies the dispersion relation and the energy velocity of waves propagating in a hollow waveguide. As a consequence, the transmitted power along a waveguide suffers slight changes when a magnetostatic field is switched on and off. This tiny effect could be better tested by operating the waveguide at a frequency close to the cutoff frequency.
REDUCING TRANSMITTED POWER OF MOVING RELAY NODE IN LONG-TERM EVOLUTION-ADVANCED CELLULAR NETWORKS
Jaafar A. Aldhaibani
2014-01-01
Full Text Available Wireless multi-hop relay networks have become very significant technologies in mobile communications. These networks ensure data rate transfer and coverage extension with a low cost. In this study two types of relay are studied; Fixed Relay Node (FRN and Moving Relay Node (MRN. Where system analyses for uplink and downlink transmission are derived in this study. Moreover the optimal relay location of FRN was proposed to provide a maximum achievable rate at user in cell edge region. Finally, a new algorithm was suggested to balance and control on the transmitted power of MRN over cell size to provide the required SNR and throughput at the users inside vehicle with reducing the consumption transmitted relay power. Numerical results indicate an enhancement in received signal strength for users at the cell edge from (-90 to -65 dBm and 40% increment from all cell size after deploying FRN at proposed locations. As well as, the results revealed that there is saving nearly 75% from transmitted power in MRN after using proposed algorithm. ATDI simulator was used to verify the numerical results, which deals with real digital cartographic and standard formats for terrain.
HAN Shuangfeng; ZHOU Shidong; WANG Jing; PARK Woogoo
2006-01-01
High spectral efficiency distributed antenna systems (DAS) require vertical Bell-Labs layered space-time (V-BLAST) like spatial multiplexing schemes. However, unlike normal point-to-point multiple input multiple output (MIMO) channels, DAS channels have different large-scale fadings from different transmit antennas, thus making equal power and rate transmission that is feasible in MIMO channels unrealistic in DAS channels. This paper proposes a novel transmit antenna selection scheme with power and rate allocation. The scheme is based on large-scale fading (shadow fading and path loss) and is suitable for V-BLAST structures with zero-forcing and successive interference cancellation (ZF-SIC) receivers, ensuring balanced average symbol error rate (SER) performance in each layer. On the receiver side, a fixed detection order is used, which is obtained in the transmit antenna selection process. Simulation results show that the proposed scheme gives good performance gains over equal power and rate transmission systems without antenna selection.
Maximal power output estimates the MLSS before and after aerobic training
Carolina Franco Wilke; Guilherme Passos Ramos; André Maia Lima; Christian Emmanuel Torres Cabido; Cristiano Lino Monteiro de Barros; Thiago Teixeira Mendes; Emerson Silami Garcia
2014-01-01
The purpose of this study is to present an equation to predict the maximal lactate steady state (MLSS) through a VO2peak incremental protocol. Twenty-six physically active men were divided in two groups (G1 and G2). They performed one maximal incremental test to determine their VO2peak and maximal power output (Wpeak), and also several constant intensity tests to determine MLSS intensity (MLSSw) on a cycle ergometer. Group G2 underwent six weeks of aerobic training at MLSSw. A regression equa...
Rouis Majdi
2016-06-01
Full Text Available The aim of this study was to verify the impact of ethnicity on the maximal power-vertical jump relationship. Thirty-one healthy males, sixteen Caucasian (age: 26.3 ± 3.5 years; body height: 179.1 ± 5.5 cm; body mass: 78.1 ± 9.8 kg and fifteen Afro-Caribbean (age: 24.4 ±2.6 years; body height: 178.9 ± 5.5 cm; body mass: 77.1 ± 10.3 kg completed three sessions during which vertical jump height and maximal power of lower limbs were measured. The results showed that the values of vertical jump height and maximal power were higher for Afro-Caribbean participants (62.92 ± 6.7 cm and 14.70 ± 1.75 W∙kg-1 than for Caucasian ones (52.92 ± 4.4 cm and 12.75 ± 1.36 W∙kg-1. Moreover, very high reliability indices were obtained on vertical jump (e.g. 0.95 < ICC < 0.98 and maximal power performance (e.g. 0.75 < ICC < 0.97. However, multiple linear regression analysis showed that, for a given value of maximal power, the Afro-Caribbean participants jumped 8 cm higher than the Caucasians. Together, these results confirmed that ethnicity impacted the maximal power-vertical jump relationship over three sessions. In the current context of cultural diversity, the use of vertical jump performance as a predictor of muscular power should be considered with caution when dealing with populations of different ethnic origins.
Mohsen Taherbaneh
2010-01-01
Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.
Yu, Aifang; Chen, Xiangyu; Wang, Rui; Liu, Jingyu; Luo, Jianjun; Chen, Libo; Zhang, Yang; Wu, Wei; Liu, Caihong; Yuan, Hongtao; Peng, Mingzeng; Hu, Weiguo; Zhai, Junyi; Wang, Zhong Lin
2016-04-26
In this paper, we demonstrate an application of a triboelectric nanogenerator (TENG) as a self-powered communication unit. An elaborately designed TENG is used to translate a series of environmental triggering signals into binary digital signals and drives an electronic-optical device to transmit binary digital data in real-time without an external power supply. The elaborately designed TENG is built in a membrane structure that can effectively drive the electronic-optical device in a bandwidth from 1.30 to 1.65 kHz. Two typical communication modes (amplitude-shift keying and frequency-shift keying) are realized through the resonant response of TENG to different frequencies, and two digital signals, i.e., "1001" and "0110", are successfully transmitted and received through this system, respectively. Hence, in this study, a simple but efficient method for directly transmitting ambient vibration to the receiver as a digital signal is established using an elaborately designed TENG and an optical communication technique. This type of the communication system, as well as the implementation method presented, exhibits great potential for applications in the smart city, smart home, password authentication, and so on.
Daley, Alison Moriarty
2012-01-01
This article examines school-based health centers (SBHCs) as complex adaptive systems, the current gaps that exist in contraceptive access, and the potential to maximize this community resource in teen pregnancy and sexually transmitted infection (STI) prevention efforts. Adolescent pregnancy is a major public health challenge for the United States. Existing community resources need to be considered for their potential to impact teen pregnancy and STI prevention efforts. SBHCs are one such community resource to be leveraged in these efforts. They offer adolescent-friendly primary care services and are responsive to the diverse needs of the adolescents utilizing them. However, current restrictions on contraceptive availability limit the ability of SBHCs to maximize opportunities for comprehensive reproductive care and create missed opportunities for pregnancy and STI prevention. A clinical case explores the current models of health care services related to contraceptive care provided in SBHCs and the ability to meet or miss the needs of an adolescent seeking reproductive care in a SBHC.
Using Maximal Isometric Force to Determine the Optimal Load for Measuring Dynamic Muscle Power
Spiering, Barry A.; Lee, Stuart M. C.; Mulavara, Ajitkumar P.; Bentley, Jason R.; Nash, Roxanne E.; Sinka, Joseph; Bloomberg, Jacob J.
2009-01-01
Maximal power output occurs when subjects perform ballistic exercises using loads of 30-50% of one-repetition maximum (1-RM). However, performing 1-RM testing prior to power measurement requires considerable time, especially when testing involves multiple exercises. Maximal isometric force (MIF), which requires substantially less time to measure than 1-RM, might be an acceptable alternative for determining the optimal load for power testing. PURPOSE: To determine the optimal load based on MIF for maximizing dynamic power output during leg press and bench press exercises. METHODS: Twenty healthy volunteers (12 men and 8 women; mean +/- SD age: 31+/-6 y; body mass: 72 +/- 15 kg) performed isometric leg press and bench press movements, during which MIF was measured using force plates. Subsequently, subjects performed ballistic leg press and bench press exercises using loads corresponding to 20%, 30%, 40%, 50%, and 60% of MIF presented in randomized order. Maximal instantaneous power was calculated during the ballistic exercise tests using force plates and position transducers. Repeated-measures ANOVA and Fisher LSD post hoc tests were used to determine the load(s) that elicited maximal power output. RESULTS: For the leg press power test, six subjects were unable to be tested at 20% and 30% MIF because these loads were less than the lightest possible load (i.e., the weight of the unloaded leg press sled assembly [31.4 kg]). For the bench press power test, five subjects were unable to be tested at 20% MIF because these loads were less than the weight of the unloaded aluminum bar (i.e., 11.4 kg). Therefore, these loads were excluded from analysis. A trend (p = 0.07) for a main effect of load existed for the leg press exercise, indicating that the 40% MIF load tended to elicit greater power output than the 60% MIF load (effect size = 0.38). A significant (p . 0.05) main effect of load existed for the bench press exercise; post hoc analysis indicated that the effect of
Maximal loads acting on legs of powered roof support unit in longwalls with bumping hazards
StanislawSzweda
2001-01-01
In the article the results of measurements of the resultant force in the legs of a powered roof support unit, caused by a dynamic interaction bf the rock mass, are discussed. The measurements have been taken in the Iongwalls mined with a roof fall, characterized by the highest degree of bumping hazard. It has been stated that the maximal force in the legs Fro, recorded during a dynamic interaction of the rock mass, is proportional to the initial static force in the legs Fst.p Therefore a need for a careful selection of the initial load of the powered roof support, according to the local mining and geological conditions, results from such a statement. Setting the legs with the supporting load exceeding the indispensable value for keeping the direct roof solids in balance, deteriorating the operational parameters of a Iongwall system also has a disadvantageous influence on the value of the force in the legs and the rate of its increase, caused by a dynamic interaction of the rock mass. A correct selection of the initial load causes a decrease in the intensity of a dynamic interaction of the rock mass on powered roof supports, which also has an advanta igeous influence on their life, Simultaneously with the measurements of the resultant force in the legs, the vertical acceleration of the canopy was also recorded. It has enabled to prove that the external dynamic forces may act on the unit both from the roof as well as from the floor. The changes of the force in the legs caused by dynamic phenomena intrinsically created in the roof and changes of the force in the legs caused by blasting explosives in the roof of the working, have been analyzed separately. It has been stated that an increase in the loads of legs, caused by intrinsic phenomena is significantly higher than a force increase in the legs caused by blasting. It means that powered roof supports, to be operated in the workings, where the bumping hazard occurs, will also transmit the loads acting on a unit
Does power indicate capacity? 30-s Wingate anaerobic test vs. maximal accumulated O2 deficit.
Minahan, C; Chia, M; Inbar, O
2007-10-01
The purpose of this study was to evaluate the relationship between anaerobic power and capacity. Seven men and seven women performed a 30-s Wingate Anaerobic Test on a cycle ergometer to determine peak power, mean power, and the fatigue index. Subjects also cycled at a work rate predicted to elicit 120 % of peak oxygen uptake to exhaustion to determine the maximal accumulated O (2) deficit. Peak power and the maximal accumulated O (2) deficit were significantly correlated (r = 0.782, p = 0.001). However, when the absolute difference in exercise values between groups (men and women) was held constant using a partial correlation, the relationship diminished (r = 0.531, p = 0.062). In contrast, we observed a significant correlation between fatigue index and the maximal accumulated O (2) deficit when controlling for gender (r = - 0.597, p = 0.024) and the relationship remained significant when values were expressed relative to active muscle mass. A higher anaerobic power does not indicate a greater anaerobic capacity. Furthermore, we suggest that the ability to maintain power output during a 30-s cycle sprint is related to anaerobic capacity.
Souza, Kristopher Mendes; de Lucas, Ricardo Dantas; do Nascimento Salvador, Paulo Cesar; Guglielmo, Luiz Guilherme Antonacci; Caritá, Renato Aparecido Corrêa; Greco, Camila Coelho; Denadai, Benedito Sérgio
2015-09-01
The aim of this study was to investigate whether the maximal power output (Pmax) during an incremental test was dependent on the curvature constant (W') of the power-time relationship. Thirty healthy male subjects (maximal oxygen uptake = 3.58 ± 0.40 L·min(-1)) performed a ramp incremental cycling test to determine the maximal oxygen uptake and Pmax, and 4 constant work rate tests to exhaustion to estimate 2 parameters from the modeling of the power-time relationship (i.e., critical power (CP) and W'). Afterwards, the participants were ranked according to their magnitude of W'. The median third was excluded to form a high W' group (HIGH, n = 10), and a low W' group (LOW, n = 10). Maximal oxygen uptake (3.84 ± 0.50 vs. 3.49 ± 0.37 L·min(-1)) and CP (213 ± 22 vs. 200 ± 29 W) were not significantly different between HIGH and LOW, respectively. However, Pmax was significantly greater for the HIGH (337 ± 23 W) than for the LOW (299 ± 40 W). Thus, in physically active individuals with similar aerobic parameters, W' influences the Pmax during incremental testing.
Determination of the peak power output during maximal brief pedalling bouts.
Nakamura, Y; Mutoh, Y; Miyashita, M
1985-01-01
The purpose of this study was to propose an optimization procedure for determining power output during very brief maximal pedalling exercise. Twenty-six healthy male students (21-28 years) performed anaerobic tests on a Monark bicycle ergometer with maximal effort for less than 10 s at eight different loads ranging from 28.1 to 84.2 Nm in pedalling moment. The maximal pedalling rate was determined from the minimal time required for one rotation of the cycle wheel. Pedalling rate decreased linearly with the load. The relationship between load and pedalling rate was represented by two linear regression equations for each subject; one regression equation was determined from eight pairs of pedalling rates and loads (r less than -0.976) and the other from three pairs (at 28.1, 46.8, 65.5 Nm; r less than -0.969). The two regression coefficients of the respective regression equations were almost identical. Mean +/- S.D. of maximal power output (Pmax) which was determined for each subject based on the two linear regression equations for eight pairs and three pairs of pedalling rates and loads was 930 +/- 187 W (13.4 +/- 1.6 W kgBW-1) and 927 +/- 187 W (13.4 +/- 1.6 W kgBW-1), respectively. There was no statistically significant difference between the values of Pmax which were obtained from each equation. It was concluded that maximal anaerobic power could be simply determined by performing maximal cycling exercise at three different loads.
Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks
Li, Shanshan; Zhou, Xiaotian; Wang, Cheng-Xiang; Yuan, Dongfeng; Zhang, Wensheng
2017-01-01
In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement. PMID:28677636
The Measurement of Maximal (Anaerobic Power Output on a Cycle Ergometer: A Critical Review
Tarak Driss
2013-01-01
Full Text Available The interests and limits of the different methods and protocols of maximal (anaerobic power ( assessment are reviewed: single all-out tests versus force-velocity tests, isokinetic ergometers versus friction-loaded ergometers, measure of during the acceleration phase or at peak velocity. The effects of training, athletic practice, diet and pharmacological substances upon the production of maximal mechanical power are not discussed in this review mainly focused on the technical (ergometer, crank length, toe clips, methodological (protocols and biological factors (muscle volume, muscle fiber type, age, gender, growth, temperature, chronobiology and fatigue limiting in cycling. Although the validity of the Wingate test is questionable, a large part of the review is dedicated to this test which is currently the all-out cycling test the most often used. The biomechanical characteristics specific of maximal and high speed cycling, the bioenergetics of the all-out cycling exercises and the influence of biochemical factors (acidosis and alkalosis, phosphate ions… are recalled at the beginning of the paper. The basic knowledge concerning the consequences of the force-velocity relationship upon power output, the biomechanics of sub-maximal cycling exercises and the study on the force-velocity relationship in cycling by Dickinson in 1928 are presented in Appendices.
In vivo muscle force and muscle power during near-maximal frog jumps.
Moo, Eng Kuan; Peterson, Daniel R; Leonard, Timothy R; Kaya, Motoshi; Herzog, Walter
2017-01-01
Frogs' outstanding jumping ability has been associated with a high power output from the leg extensor muscles. Two main theories have emerged to explain the high power output of the frog leg extensor muscles, either (i) the contractile conditions of all leg extensor muscles are optimized in terms of muscle length and speed of shortening, or (ii) maximal power is achieved through a dynamic catch mechanism that uncouples fibre shortening from the corresponding muscle-tendon unit shortening. As in vivo instantaneous power generation in frog hind limb muscles during jumping has never been measured directly, it is hard to distinguish between the two theories. In this study, we determined the instantaneous variable power output of the plantaris longus (PL) of Lithobates pipiens (also known as Rana pipiens), by directly measuring the in vivo force, length change, and speed of muscle and fibre shortening in near maximal jumps. Fifteen near maximal jumps (> 50cm in horizontal distance) were analyzed. High instantaneous peak power in PL (536 ± 47 W/kg) was achieved by optimizing the contractile conditions in terms of the force-length but not the force-velocity relationship, and by a dynamic catch mechanism that decouples fascicle shortening from muscle-tendon unit shortening. We also found that the extra-muscular free tendon likely amplifies the peak power output of the PL by modulating fascicle shortening length and shortening velocity for optimum power output, but not by releasing stored energy through recoiling as the tendon only started recoiling after peak PL power had been achieved.
In vivo muscle force and muscle power during near-maximal frog jumps
Leonard, Timothy R.; Kaya, Motoshi; Herzog, Walter
2017-01-01
Frogs’ outstanding jumping ability has been associated with a high power output from the leg extensor muscles. Two main theories have emerged to explain the high power output of the frog leg extensor muscles, either (i) the contractile conditions of all leg extensor muscles are optimized in terms of muscle length and speed of shortening, or (ii) maximal power is achieved through a dynamic catch mechanism that uncouples fibre shortening from the corresponding muscle-tendon unit shortening. As in vivo instantaneous power generation in frog hind limb muscles during jumping has never been measured directly, it is hard to distinguish between the two theories. In this study, we determined the instantaneous variable power output of the plantaris longus (PL) of Lithobates pipiens (also known as Rana pipiens), by directly measuring the in vivo force, length change, and speed of muscle and fibre shortening in near maximal jumps. Fifteen near maximal jumps (> 50cm in horizontal distance) were analyzed. High instantaneous peak power in PL (536 ± 47 W/kg) was achieved by optimizing the contractile conditions in terms of the force-length but not the force-velocity relationship, and by a dynamic catch mechanism that decouples fascicle shortening from muscle-tendon unit shortening. We also found that the extra-muscular free tendon likely amplifies the peak power output of the PL by modulating fascicle shortening length and shortening velocity for optimum power output, but not by releasing stored energy through recoiling as the tendon only started recoiling after peak PL power had been achieved. PMID:28282405
Maximal loads acting on legs of powered roof support unit in longwalls with bumping hazards
Stanislaw Szweda
2001-01-01
In the article the results of measurements of the resultant force in th e legs of a powered roof support unit, caused by a dynamic interaction of the ro ck mass, are discussed. The measurements have been taken in the longwalls mined with a roof fall, characterized by the highest degree of bumping hazard. It has been stated that the maximal force in the legs Fm, recorded during a dynam ic interaction of the rock mass, is proportional to the initial static force in the legs Fst,p. Th erefore a need for a careful selection of the initial load of the powered roof s upport, according to the local mining and geological conditions, results from su ch a statement. Setting the legs with the supporting load exceeding the indispen sable value for keeping the direct roof solids in balance, deteriorating the ope rational parameters of a longwall system also has a disadvantageous influence on the value of the force in the legs and the rate of its increase, caused by a dy namic interaction of the rock mass. A correct selection of the initial load caus es a decrease in the intensity of a dynamic interaction of the rock mass on powe red roof supports, which also has an advantageous influence on their life. Simultaneously with the measurements of the resultant force in the legs, the vertical acceleration of the canopy was also recorded. It has enabled to prove that the exte rnal dynamic forces may act on the unit both from the roof as well as from the f loor. The changes of the force in the legs caused by dynamic phenomena intrinsic ally created in the roof and changes of the force in the legs caused by blasting explosives in the roof of the working, have been analyzed separately. It has been stated that an increase in the loads of legs, caused by intrinsi c phenomena is significantly higher than a force increase in the legs caused by blasting. It means that powered roof supports, to be operated in the workings, w here the bumping hazard occurs, will also transmit the loads
S. T. Jaya Christa
2006-06-01
Full Text Available This paper deals with the optimal location and parameters of Unified Power Flow Controllers (UPFCs in electrical power systems, using particle swarm optimization (PSO. The objective is to maximize the transmission system loadability subject to the transmission line capacity limits and specified bus voltage levels. Using the proposed method, the location of UPFCs and their parameters are optimized simultaneously. PSO is used to solve the above non-linear programming problem for better accuracy. The proposed approach is examined and tested on IEEE 30-bus system and IEEE 118-bus system. The results obtained are quite promising for the power system operation environment
Hanif, Muhammad
2017-03-31
The high hardware cost associated with multiple antennas at the secondary transmitter of an underlay cognitive radio (CR) can be reduced by antenna selection. This paper analyzes different power adaptive transmit antenna selection (TAS) schemes for an underlay CR, which ensure that the instantaneous interference caused by the secondary transmitter to the primary receiver is below a predetermined level. We consider the optimal continuous power adaptive TAS and present a low-complexity antenna and power level selection scheme, named sequential antenna and power level selection scheme (SAPS), for discrete power adaptation. Exact statistical characterizations of the signal-to-interference plus noise ratio at the secondary receiver are derived for the considered schemes. Based on the newly derived statistics, we prove that the considered schemes achieve the highest diversity order equaling the number of antennas at the secondary transmitter. Further, we also derive a closed-form expression of the ergodic capacity for the underlay CR with SAPS scheme. Finally, we show that the proposed scheme outperforms existing schemes in terms of ergodic capacity.
Jalil Ataee
2014-06-01
Full Text Available Accommodation resistance is a training technique that may improve strength and power gains beyond those achieved by traditional free weights. In this method, chains are either added on a free-weight bar and combined with traditional plates or added to the bar as the entire load. Purpose. The aim of the current study was to compare the effectiveness of accommodation and constant resistance training methods during a four-week period on maximal strength and power in trained athletes. Methods. This study was comprised of 24 trained athletes, including 16 trained males [8 Wushu athletes (Kung-Fu and 8 wrestlers, age: 20.5 ± 2.00 yrs. old]. Participants were initially tested on weight, body circumference, fat percent, upper and lower body maximal strength, determined by the 1-repetition maximum (1RM test, which determines the greatest amount of weight a person can successfully lift, and upper and lower body power. Participants were equally randomized to either accommodation or constant resistance training groups. Both groups underwent resistance training for a four-week period that consisted of three sessions per week. Multivariate repeated-measures analyses of variance of the data were used to verify significant differences in strength and power between groups. The modified Bonferroni post hoc test was used to compare the obtained results in pre-, mid-, and post test. Results. In the accommodation resistance group, there was a significant difference in lower body maximal strength compared to the constant group (163.12 ± 18.82 kg in the accommodation group vs. 142.25 ± 20.04 kg in the constant group, P = 0.04. No significant differences were found in upper body power, lower body power, and upper body maximal strength between the two groups (P > 0.05. Conclusion. Although there was only a significant difference in lower body maximal strength between groups, accommodation resistance training may induce a physiological training response by improving
Morimoto, Shigeo; Nakamura, Tomohiko; Takeda, Yoji
This paper proposes the sensorless output power maximization control of the wind generation system. A permanent magnet synchronous generator (PMSG) is used as a variable speed generator in the proposed system. The generator torque is suitably controlled according to the generator speed and thus the power from a wind turbine settles down on the maximum power point by the proposed MPPT control method, where the information of wind velocity is not required. Moreover, the maximum available generated power is obtained by the optimum current vector control. The current vector of PMSG is optimally controlled according to the generator speed and the required torque in order to minimize the losses of PMSG considering the voltage and current constraints. The proposed wind power generation system can be achieved without mechanical sensors such as a wind velocity detector and a position sensor. Several experimental results show the effectiveness of the proposed control method.
Optimal design parameters of the bicycle-rider system for maximal muscle power output.
Yoshihuku, Y; Herzog, W
1990-01-01
The purpose of this study was to find the optimal values of design parameters for a bicycle-rider system (crank length, pelvic inclination, seat height, and rate of crank rotation) which maximize the power output from muscles of the human lower limb during bicycling. The human lower limb was modelled as a planar system of five rigid bodies connected by four smooth pin joints and driven by seven functional muscle groups. The muscles were assumed to behave according to an adapted form of Hill's equation. The dependence of the average power on the design parameters was examined. The instantaneous power of each muscle group was studied and simultaneous activity of two seemingly antagonistic muscle groups was analyzed. Average peak power for one full pedal revolution was found to be around 1100 W. The upper body position corresponding to this peak power output was slightly reclined, and the pedalling rate was 155 rpm for a nominal crank length of 170 mm.
Lithium-thionyl chloride battery design concepts for maximized power applications
Kane, P.; Marincic, N.
The need for primary batteries configured to deliver maximized power has been asserted by many different procuring activities. Battery Engineering Inc. has developed some specific design concepts and mastered some specialized techniques utilized in the production of this type of power source. The batteries have been successfully bench tested during the course of virtually all of these programs, with ultimate success coming in the form of two successful test launches under the USAF Plasma Effects Decoy Program. This paper briefly discusses some of these design concepts and the rationale behind them.
Wind tunnel testing of a closed-loop wake deflection controller for wind farm power maximization
Campagnolo, Filippo; Petrović, Vlaho; Schreiber, Johannes; Nanos, Emmanouil M.; Croce, Alessandro; Bottasso, Carlo L.
2016-09-01
This paper presents results from wind tunnel tests aimed at evaluating a closed- loop wind farm controller for wind farm power maximization by wake deflection. Experiments are conducted in a large boundary layer wind tunnel, using three servo-actuated and sensorized wind turbine scaled models. First, we characterize the impact on steady-state power output of wake deflection, achieved by yawing the upstream wind turbines. Next, we illustrate the capability of the proposed wind farm controller to dynamically driving the upstream wind turbines to the optimal yaw misalignment setting.
A new approach to assessing maximal aerobic power in children: the Odense School Child Study.
Hansen, H S; Froberg, K; Nielsen, J R; Hyldebrandt, N
1989-01-01
In two experiments maximal aerobic power (VO2max) calculated from maximal mechanical power (Wmax) was evaluated in 39 children aged 9-11 years. A maximal multi-stage cycle ergometer exercise test was used with an increase in work load every 3 min. In the first experiment oxygen consumption was measured in 18 children during each of the prescribed work loads and a correction factor was calculated to estimate VO2max using the equation VO2max = 12.Wmax + 5.weight. An appropriate increase in work rate based on height was determined for boys (0.16 W.cm-1) and girls (0.15 W.cm-1) respectively. In the second experiment 21 children performed a maximal cycle ergometer exercise test twice. In addition to the procedure in the first experiment a similar exercise test was performed, but without measurement of oxygen uptake. Calculated VO2max correlated significantly (p less than 0.01) with those values measured in both boys (r = 0.90) and girls (r = 0.95) respectively, and the standard error of estimation for VO2max (calculated) on VO2max (measured) was less than 3.2%. Two expressions of relative work load (%VO2max and %Wmax) were established and found to be closely correlated. The relative work load in %VO2max could be predicted from the relative work load in %Wmax with an average standard error of 3.8%. The data demonstrate that calculated VO2max based on a maximal multi-stage exercise test provides an accurate and valid estimate of VO2max.
Enhanced Cell-Edge Performance with Transmit Power-Shaping and Multipoint, Multiflow Techniques
Philip Pietrask; Gregg Charltonl; Rui Yang,; Carl Wang
2011-01-01
In this paper, we present a technique called ＂fuzzy cells＂ that builds on the multicarrier features of Long Term Evolution-Advanced （LTE-A） and high-speed packet access （HSPA）. Multiple carriers are aggregated to create a larger system bandwidth, and these carriers are transmitted at different powers by each sector antenna. This creates a set of cell-edge locations that differ from one frequency to the next. System-level simulations are performed to estimate individual user and average throughput for a hexagonal deployment of 3-sector base stations. For moderately high loads, a fuzzy cell deployment can improve tenth percentile （cell-edge） user throughput by 100% and can improve average throughput by about 30% compared with a reuse 1 scheme. Fuzzy ceils reduce inter-cell interference in the same way as higher-order reuse schemes and allow users to access the full system bandwidth.
Gil Gye-Tae
2010-01-01
Full Text Available Packet scheduler plays the central role in determining the overall performance of the 3GPP long-term evolution (LTE based on packet-switching operation. In this paper, a novel minimum transmit power-based (MP packet-scheduling algorithm is proposed that can achieve power-efficient transmission to the UEs while providing both system throughput gain and fairness improvement. The proposed algorithm is based on a new scheduling metric focusing on the ratio of the transmit power per bit and allocates the physical resource block (PRB to the UE that requires the least ratio of the transmit power per bit. Through computer simulation, the performance of the proposed MP packet-scheduling algorithm is compared with the conventional packet-scheduling algorithms by two primary criteria: fairness and throughput. The simulation results show that the proposed algorithm outperforms the conventional algorithms in terms of the fairness and throughput.
NIU Junchuan; GE Peiqi; HOU Cuirong; LIM C W; SONG Kongjie
2009-01-01
For estimating the vibration transmission accurately and performing vibration control efficiently in isolation systems, a novel general model is presented to predict the power flow transmitted into the complicate flexible bases of laminated beams. In the model, the laminated beam bases are simulated by the first-order shear deformation laminated plate theory, which is relatively simple and economic but accurate in predicting the vibration solutions of flexible isolation systems with laminated beam bases in comparison with classical laminated beam theories and higher order theories. On the basis of the presented model, substructure technique and variational principle are employed to obtain the governing equation of the isolation system and the power flow solution. Then, the vibration characteristics of the flexible isolation systems with laminated bases are investigated. Several numerical examples are given to show the validity and efficiency of the presented model. It is concluded that the presented model is the extension of the classical one and it can obtain more accurate power flow solutions.
Squat jump training at maximal power loads vs. heavy loads: effect on sprint ability.
Harris, Nigel K; Cronin, John B; Hopkins, Will G; Hansen, Keir T
2008-11-01
Training at a load maximizing power output (Pmax) is an intuitively appealing strategy for enhancement of performance that has received little research attention. In this study we identified each subject's Pmax for an isoinertial resistance training exercise used for testing and training, and then we related the changes in strength to changes in sprint performance. The subjects were 18 well-trained rugby league players randomized to two equal-volume training groups for a 7-week period of squat jump training with heavy loads (80% 1RM) or with individually determined Pmax loads (20.0-43.5% 1RM). Performance measures were 1RM strength, maximal power at 55% of pretraining 1RM, and sprint times for 10 and 30 m. Percent changes were standardized to make magnitude-based inferences. Relationships between changes in these variables were expressed as correlations. Sprint times for 10 m showed improvements in the 80% 1RM group (-2.9 +/- 3.2%) and Pmax group (-1.3 +/- 2.2%), and there were similar improvements in 30-m sprint time (-1.9 +/- 2.8 and -1.2 +/- 2.0%, respectively). Differences in the improvements in sprint time between groups were unclear, but improvement in 1RM strength in the 80% 1RM group (15 +/- 9%) was possibly substantially greater than in the Pmax group (11 +/- 8%). Small-moderate negative correlations between change in 1RM and change in sprint time (r approximately -0.30) in the combined groups provided the only evidence of adaptive associations between strength and power outputs, and sprint performance. In conclusion, it seems that training at the load that maximizes individual peak power output for this exercise with a sample of professional team sport athletes was no more effective for improving sprint ability than training at heavy loads, and the changes in power output were not usefully related to changes in sprint ability.
Du, Sijun; Jia, Yu; Seshia, Ashwin
2015-12-01
A resonant vibration energy harvester typically comprises of a clamped anchor and a vibrating shuttle with a proof mass. Piezoelectric materials are embedded in locations of high strain in order to transduce mechanical deformation into electric charge. Conventional design for piezoelectric vibration energy harvesters (PVEH) usually utilizes piezoelectric material and metal electrode layers covering the entire surface area of the cantilever with no consideration provided to examining the trade-off involved with respect to maximizing output power. This paper reports on the theory and experimental verification underpinning optimization of the active electrode area of a cantilevered PVEH in order to maximize output power. The analytical formulation utilizes Euler-Bernoulli beam theory to model the mechanical response of the cantilever. The expression for output power is reduced to a fifth order polynomial expression as a function of the electrode area. The maximum output power corresponds to the case when 44% area of the cantilever is covered by electrode metal. Experimental results are also provided to verify the theory.
Maximal Sprint Power in Road Cyclists After Variable and Nonvariable High-Intensity Exercise.
Menaspà, Paolo; Martin, David T; Victor, James; Abbiss, Chris R
2015-11-01
This study compared the sprint performance of professional cyclists after 10 minutes of variable (VAR) or nonvariable (N-VAR) high-intensity cycling with sprint performance in a rested state. Ten internationally competitive male cyclists (mean ± SD: age, 20.1 ± 1.3 years; stature, 1.81 ± 0.07 m; body weight, 69.5 ± 4.9 kg; and V[Combining Dot Above]O2peak, 72.5 ± 4.4 ml·kg·min) performed a 12-second maximal sprint in 3 conditions: (a) a rested state, (b) after 10 minutes of N-VAR cycling, and (c) after 10 minutes of VAR cycling. The intensity during the 10-minute efforts gradually increased to replicate power output observed in the final section of cycling road races. During the VAR cycling, participants performed short (2 seconds) accelerations at 80% of their sprint peak power, every 30 seconds. Average power output, cadence, and maximal heart rate (HR) during the 10-minute efforts were similar between conditions (5.3 ± 0.2 W·kg, 102 ± 1 rpm, and 93 ± 3% HRmax). Postexercise blood lactate concentration and sessional perceived exertion were also similar (8.3 ± 1.6 mmol·L, 15.4 ± 1.3 [6-20 scale]). Peak and average power output and cadence during the subsequent maximal sprint were not different between the 3 experimental conditions (p > 0.05). In conclusion, this study showed that neither the VAR nor the N-VAR 10-minute efforts ridden in this study impaired sprint performance in elite competitive cyclists.
McNamara, John M; Stearne, David J
2013-06-01
Although there is considerable research on concurrent training, none has integrated flexible nonlinear periodization and maximal-effort cycling in the same design. The purpose of this investigation was to test outcome measures of strength and power using a pretest-posttest randomized groups design. A strength and endurance (SE) group was compared with a strength, endurance, and maximal-effort cycling (SEC) group. Both groups used a flexible nonlinear periodization design. Thirteen male and 7 female students (mean ± SD: age, 22.5 ± 4.1 years; height, 173.5 ± 12.4 cm; weight, 79.4 ± 20.2 kg; strength training experience, 2.4 ± 2.2 years) participated in this study. Groups were not matched for age, height, weight, strength training experience, or sex, but were randomly assigned to an SE (n = 10) or SEC (n = 10) group. All training was completed within 45 minutes, twice per week (Monday and Wednesday), over 12 consecutive weeks. Both groups were assigned 6.75 total hours of aerobic conditioning, and 13.5 hours of free weight and machine exercises totaling 3,188 repetitions ranging from 5 to 20 repetition maximums. The SEC group performed 2 cycling intervals per workout ranging from 10 to 45 seconds. Pretest and posttest measures included chest press and standing broad jump. Analysis of variance showed that there were no significant differences between the SE and SEC groups on measures of chest press or standing broad jump performance (p, not significant). Paired sample t-tests (p = 0.05) showed significant improvement in strength and power in all groups (pretest to posttest), except for SE jump performance (p, not significant). In conclusion, adding maximal-effort cycling does not provide additional strength or power benefits to a concurrent flexible nonlinear training program. However, an exercise professional can take confidence that a concurrent flexible nonlinear training program can increase strength and power in healthy individuals.
Suresh Chintalapudi Venkata
2015-09-01
Full Text Available In this paper a novel non-linear optimization problem is formulated to maximize the social welfare in restructured environment with generalized unified power flow controller (GUPFC. This paper presents a methodology to optimally allocate the reactive power by minimizing voltage deviation at load buses and total transmission power losses so as to maximize the social welfare. The conventional active power generation cost function is modified by combining costs of reactive power generated by the generators, shunt capacitors and total power losses to it. The formulated objectives are optimized individually and simultaneously as multi-objective optimization problem, while satisfying equality, in-equality, practical and device operational constraints. A new optimization method, based on two stage initialization and random distribution processes is proposed to test the effectiveness of the proposed approach on IEEE-30 bus system, and the detailed analysis is carried out.
Benotsch, Eric G; Sawyer, Ashlee N; Martin, Aaron M; Allen, Elizabeth S; Nettles, Christopher D; Richardson, Doug; Rietmeijer, Cornelis A
2017-01-01
In prior research, having traits consistent with a personality disorder has been shown to be related to substance use and high-risk sexual activity; however, few studies have examined relationships between dependency traits and health-jeopardizing behaviors. Individuals with traits consistent with dependent personality disorder may be more likely to be in a primary relationship characterized by unhealthy conditions, including physical abuse from a partner, low assertiveness in sexual situations, and partner infidelity. In addition, dependency traits may be associated with unhealthy coping (e.g., through substance use). To examine associations between dependent personality traits and these types of health-related behaviors, 198 women seeking sexually transmitted infection clinic services completed a computer-assisted assessment of dependent personality traits, substance use, unhealthy conditions in primary relationships, perceived sexual and relationship power, and sexual risk related to condom use. Dependency trait scores were correlated with the use of cocaine, heroin, and methamphetamine. Participants high in dependency traits reported low perceived power within their relationships and less say in sexual behaviors, including condom use. In a series of multivariate analyses, dependency traits significantly predicted having been hit by a partner, staying with a partner after he cheated, having sex because of threats, and fear of asking a partner to use a condom. Dependency traits were also associated with lower past condom use and lower future condom use intentions. Results suggest that dependent personality traits may place women at higher risk for physical abuse and harmful health behaviors.
Reliability of Maximal Back Squat and Power Clean Performances in Inexperienced Athletes.
Comfort, Paul; McMahon, John J
2015-11-01
The aim of the study was to determine between-session reliability of maximal weight lifted during the back squat and power clean, in inexperienced athletes, and to identify the smallest detectable difference between sessions. Forty-four collegiate athletes (men: n = 32; age: 21.5 ± 2.0 years; height: 180.0 ± 6.1 cm; body mass: 81.01 ± 7.42 kg; women: n = 12; age: 21.0 ± 1.9 years; height: 169.0 ± 5.2 cm; body mass: 62.90 ± 7.46 kg) participated in this study. One repetition maximum (1RM) back squat and power cleans were each performed twice on separate days, 3-5 days apart. Paired samples' t tests revealed no significant differences between trial 1 and trial 2 of the power clean (70.55 ± 24.24 kg, 71.22 ± 23.87 kg, p > 0.05, power = 0.99) and the back squat (130.32 ± 34.05 kg, 129.82 ± 34.07 kg, p > 0.05, power = 1.0). No differences in reliability or measurement error were observed between men and women. Intraclass correlation coefficients (ICCs) demonstrated a high reliability (ICC = 0.997, p clean with an R of 0.987; similarly, high reliability was observed for between-session back squat performances (ICC = 0.994, p 5% to identify a meaningful change in both maximal back squat and power clean performance.
Maximizing photovoltaic power generation of a space-dart configured satellite
Lee, Dae Young; Cutler, James W.; Mancewicz, Joe; Ridley, Aaron J.
2015-06-01
Many small satellites are power constrained due to their minimal solar panel area and the eclipse environment of low-Earth orbit. As with larger satellites, these small satellites, including CubeSats, use deployable power arrays to increase power production. This presents a design opportunity to develop various objective functions related to energy management and methods for optimizing these functions over a satellite design. A novel power generation model was created, and a simulation system was developed to evaluate various objective functions describing energy management for complex satellite designs. The model uses a spacecraft-body-fixed spherical coordinate system to analyze the complex geometry of a satellite's self-induced shadowing with computation provided by the Open Graphics Library. As an example design problem, a CubeSat configured as a space-dart with four deployable panels is optimized. Due to the fast computation speed of the solution, an exhaustive search over the design space is used to find the solar panel deployment angles which maximize total power generation. Simulation results are presented for a variety of orbit scenarios. The method is extendable to a variety of complex satellite geometries and power generation systems.
Optimal Operation of Network-Connected Combined Heat and Powers for Customer Profit Maximization
Da Xie
2016-06-01
Full Text Available Network-connected combined heat and powers (CHPs, owned by a community, can export surplus heat and electricity to corresponding heat and electric networks after community loads are satisfied. This paper proposes a new optimization model for network-connected CHP operation. Both CHPs’ overall efficiency and heat to electricity ratio (HTER are assumed to vary with loading levels. Based on different energy flow scenarios where heat and electricity are exported to the network from the community or imported, four profit models are established accordingly. They reflect the different relationships between CHP energy supply and community load demand across time. A discrete optimization model is then developed to maximize the profit for the community. The models are derived from the intervals determined by the daily operation modes of CHP and real-time buying and selling prices of heat, electricity and natural gas. By demonstrating the proposed models on a 1 MW network-connected CHP, results show that the community profits are maximized in energy markets. Thus, the proposed optimization approach can help customers to devise optimal CHP operating strategies for maximizing benefits.
Maximal power output estimates the MLSS before and after aerobic training
Carolina Franco Wilke
2014-06-01
Full Text Available The purpose of this study is to present an equation to predict the maximal lactate steady state (MLSS through a VO2peak incremental protocol. Twenty-six physically active men were divided in two groups (G1 and G2. They performed one maximal incremental test to determine their VO2peak and maximal power output (Wpeak, and also several constant intensity tests to determine MLSS intensity (MLSSw on a cycle ergometer. Group G2 underwent six weeks of aerobic training at MLSSw. A regression equation was created using G1 subjects Wpeak and MLSSw to estimate the MLSS intensity (MLSSweq before and after training for G2 (MLSSweq = 0.866 x Wpeak-41.734. The mean values were not different (150±27W vs 148±27W, before training / 171±26W vs 177±24W, after training and significant correlations were found between the measured and the estimated MLSSw before (r²=0.49 and after training (r²=0.62 in G2. The proposed equation was effective to estimate the MLSS intensity before and after aerobic training.
Oliver, Jonathan M.; Almada, Anthony L.; Van Eck, Leighsa E.; Shah, Meena; Mitchell, Joel B.; Jones, Margaret T.; Jagim, Andrew R.; Rowlands, David S.
2016-01-01
Athletes in sports demanding repeat maximal work outputs frequently train concurrently utilizing sequential bouts of intense endurance and resistance training sessions. On a daily basis, maximal work within subsequent bouts may be limited by muscle glycogen availability. Recently, the ingestion of a unique high molecular weight (HMW) carbohydrate was found to increase glycogen re-synthesis rate and enhance work output during subsequent endurance exercise, relative to low molecular weight (LMW) carbohydrate ingestion. The effect of the HMW carbohydrate, however, on the performance of intense resistance exercise following prolonged-intense endurance training is unknown. Sixteen resistance trained men (23±3 years; 176.7±9.8 cm; 88.2±8.6 kg) participated in a double-blind, placebo-controlled, randomized 3-way crossover design comprising a muscle-glycogen depleting cycling exercise followed by ingestion of placebo (PLA), or 1.2 g•kg•bw-1 of LMW or HMW carbohydrate solution (10%) with blood sampling for 2-h post-ingestion. Thereafter, participants performed 5 sets of 10 maximal explosive repetitions of back squat (75% of 1RM). Compared to PLA, ingestion of HMW (4.9%, 90%CI 3.8%, 5.9%) and LMW (1.9%, 90%CI 0.8%, 3.0%) carbohydrate solutions substantially increased power output during resistance exercise, with the 3.1% (90% CI 4.3, 2.0%) almost certain additional gain in power after HMW-LMW ingestion attributed to higher movement velocity after force kinematic analysis (HMW-LMW 2.5%, 90%CI 1.4, 3.7%). Both carbohydrate solutions increased post-exercise plasma glucose, glucoregulatory and gut hormones compared to PLA, but differences between carbohydrates were unclear; thus, the underlying mechanism remains to be elucidated. Ingestion of a HMW carbohydrate following prolonged intense endurance exercise provides superior benefits to movement velocity and power output during subsequent repeated maximal explosive resistance exercise. This study was registered with
Expected Power-Utility Maximization Under Incomplete Information and with Cox-Process Observations
Fujimoto, Kazufumi, E-mail: m_fuji@kvj.biglobe.ne.jp [Bank of Tokyo-Mitsubishi UFJ, Ltd., Corporate Risk Management Division (Japan); Nagai, Hideo, E-mail: nagai@sigmath.es.osaka-u.ac.jp [Osaka University, Division of Mathematical Science for Social Systems, Graduate School of Engineering Science (Japan); Runggaldier, Wolfgang J., E-mail: runggal@math.unipd.it [Universita di Padova, Dipartimento di Matematica Pura ed Applicata (Italy)
2013-02-15
We consider the problem of maximization of expected terminal power utility (risk sensitive criterion). The underlying market model is a regime-switching diffusion model where the regime is determined by an unobservable factor process forming a finite state Markov process. The main novelty is due to the fact that prices are observed and the portfolio is rebalanced only at random times corresponding to a Cox process where the intensity is driven by the unobserved Markovian factor process as well. This leads to a more realistic modeling for many practical situations, like in markets with liquidity restrictions; on the other hand it considerably complicates the problem to the point that traditional methodologies cannot be directly applied. The approach presented here is specific to the power-utility. For log-utilities a different approach is presented in Fujimoto et al. (Preprint, 2012).
An effective control strategy to maximize power extraction from wind turbines
Mouhadjer, Samir; Benmedjahed, Miloud; Neçaïbia, Ammar
2016-07-01
Among the various identifiable renewable energies sources, one holds the attention in this study for its important potential in the world; it's about wind energy. Our objective in this present work is to contribute a share to the research solution to the problems of coupling between this energy source and the load; it's about the transfer of the maximum power to the latter which often suffers from a bad matching. In order to maximize the wind power extraction, this work describes design of a PWM rectifier controller for wind turbines. Generic PWM rectifier is used and PICl6F876 Microcontroller is proposed. The goal of the controller is to keep operating point as close to the maximum efficiency as possible.
Maximizing the Social Welfare of Virtual Power Players Operation in Case of Excessive Wind Power
Faria, Pedro; Vale, Zita; Morais, Hugo
2013-01-01
that aggregates and manages the available energy resources. When facing a situation of excessive non-dispatchable generation, including wind power, real time pricing is applied in order to induce the increase of consumption so that wind curtailment is minimized. This method is especially useful when actual...... and day-ahead resources forecast differ significantly. The distribution network characteristics and concerns are addressed by including the network constraints in the optimization model. The proposed methodology has been implemented in GAMS optimization tool and its application is illustrated...
Koninckx, Erwin; Van Leemputte, Marc; Hespel, Peter
2010-07-01
The aim of this study was to compare the effects of a weight training program for the leg extensors with isokinetic cycling training (80 rpm) on maximal power output and endurance performance. Both strength training interventions were incorporated twice a week in a similar endurance training program of 12 weeks. Eighteen trained male cyclists (VO(2peak) 60 +/- 1 ml kg(-1) min(-1)) were grouped into the weight training (WT n = 9) or the isokinetic training group (IT n = 9) matched for training background and sprint power (P (max)), assessed from five maximal sprints (5 s) on an isokinetic bicycle ergometer at cadences between 40 and 120 rpm. Crank torque was measured (1 kHz) to determine the torque distribution during pedaling. Endurance performance was evaluated by measuring power, heart rate and lactate during a graded exercise test to exhaustion and a 30-min performance test. All tests were performed on subjects' individual race bicycle. Knee extension torque was evaluated isometrically at 115 degrees knee angle and dynamically at 200 degrees s(-1) using an isokinetic dynamometer. P (max) at 40 rpm increased in both the groups (~15%; P < 0.05). At 120 rpm, no improvement of P (max) was found in the IT training group, which was possibly related to an observed change in crank torque at high cadences (P < 0.05). Both groups improved their power output in the 30-min performance test (P < 0.05). Isometric knee extension torque increased only in WT (P < 0.05). In conclusion, at low cadences, P (max) improved in both training groups. However, in the IT training group, a disturbed pedaling technique compromises an improvement of P (max) at high cadences.
Aldhaibani, Jaafar A; Yahya, Abid; Ahmad, R Badlishah
2014-01-01
The poor capacity at cell boundaries is not enough to meet the growing demand and stringent design which required high capacity and throughput irrespective of user's location in the cellular network. In this paper, we propose new schemes for an optimum fixed relay node (RN) placement in LTE-A cellular network to enhance throughput and coverage extension at cell edge region. The proposed approach mitigates interferences between all nodes and ensures optimum utilization with the optimization of transmitted power. Moreover, we proposed a new algorithm to balance the transmitted power of moving relay node (MR) over cell size and providing required SNR and throughput at the users inside vehicle along with reducing the transmitted power consumption by MR. The numerical analysis along with the simulation results indicates that an improvement in capacity for users is 40% increment at downlink transmission from cell capacity. Furthermore, the results revealed that there is saving nearly 75% from transmitted power in MR after using proposed balancing algorithm. ATDI simulator was used to verify the numerical results, which deals with real digital cartographic and standard formats for terrain.
Cardenas-Valencia, Andres M.; Short, R. Timothy; Adornato, Lori; Langebrake, Larry
2010-04-01
Use of sensor systems in water bodies has applications that range from environmental and oceanographic research to port and homeland security. Power sources are often the limiting component for further reduction of sensor system size and weight. We present recent investigations of metal-anode water-activated galvanic cells, specifically water-activated Alcells using inorganic alkali peroxides and solid organic oxidizers (heterocyclic halamines), in a semi-fuel cell configuration (i.e., with cathode species generated in situ and flow-through cells). The oxidizers utilized are inexpensive solid materials that are generally (1) safer to handle than liquid solutions or gases, (2) have inherently higher current and energy capacity (as they are not dissolved), and, (3) if appropriately packaged, will not degrade over time. The specific energy (S.E.) of Al-alkali peroxide was found to be 230 Wh/kg (460 Wh/kg, considering only active materials) in a seven-gram cell. Interestingly, when the cell size was increased (making more area of the catalytic cathode electrode available), the results from a single addition of water in an Al-organic oxidizer cell (weighing ~18 grams) showed an S.E. of about 200 Wh/kg. This scalability characteristic suggests that values in excess of 400 Wh/kg could be obtained in a semi-fuel-cell-like system. In this paper, we also present design considerations that take into account the energy requirements of the pumping devices and show that the proposed oxidizers, and the possible control of the chemical equilibrium of these cathodes in solution, may help reduce this power requirement and hence enhance the overall energetic balance.
Bo LI; Sung-kwon PARK
2016-01-01
In the IEEE 802.16e/m standard, three power saving classes (PSCs) are defined to save the energy of a mobile sub-scriber station (MSS). However, how to set the parameters of PSCs to maximize the power saving and guarantee the quality of service is not specified in the standard. Thus, many algorithms were proposed to set the PSCs in IEEE 802.16 networks. However, most of the proposed algorithms consider only the power saving for a single MSS. In the algorithms designed for multiple MSSs, the sleep state, which is set for activation of state transition overhead power, is not considered. The PSC setting for real-time connections in multiple MSSs with consideration of the state transition overhead is studied. The problem is non-deterministic polynomial time hard (NP-hard), and a suboptimal algorithm for the problem is proposed. Simulation results demonstrate that the energy saving of the proposed algorithm is higher than that of state-of-the-art algorithms and approaches the optimum limit.
The effect of ephedra and caffeine on maximal strength and power in resistance-trained athletes.
Williams, Andrew D; Cribb, Paul J; Cooke, Matthew B; Hayes, Alan
2008-03-01
Caffeine and ephedrine-related alkaloids recently have been removed from International Olympic Committee banned substances lists, whereas ephedrine itself is now permissible at urinary concentrations less than 10 mug.mL. The changes to the list may contribute to an increased use of caffeine and ephedra as ergogenic aids by athletes. Consequently, we sought to investigate the effects of ingesting caffeine (C) or a combination of ephedra and caffeine (C + E) on muscular strength and anaerobic power using a double-blind, crossover design. Forty-five minutes after ingesting a glucose placebo (P: 300 mg), C (300 mg) or C + E (300 mg + 60 mg), 9 resistance-trained male participants were tested for maximal strength by bench press [BP; 1 repetition maximum (1RM)] and latissimus dorsi pull down (LP; 1RM). Subjects also performed repeated repetitions at 80% of 1RM on both BP and LP until exhaustion. After this test, subjects underwent a 30-second Wingate test to determine peak anaerobic cycling power, mean power, and fatigue index. Although subjects reported increased alertness and enhanced mood after supplementation with caffeine and ephedra, there were no significant differences between any of the treatments in muscle strength, muscle endurance, or peak anaerobic power. Our results do not support the contention that supplementation with ephedra or caffeine will enhance either muscle strength or anaerobic exercise performance.
Effects of temperature on the maximal instantaneous muscle power of humans.
Ferretti, G; Ishii, M; Moia, C; Cerretelli, P
1992-01-01
The maximal instantaneous muscle power (wi,max) probably reflects the maximal rate of adenosine 5'-triphosphate (ATP) hydrolysis (ATPmax), a temperature-dependent variable, which gives rise to the hypothesis that temperature, by affecting ATPmax, may also influence wi,max. This hypothesis was tested on six subjects, whose vastus lateralis muscle temperature (Tmuscle) was monitored by a thermocouple inserted approximately 3 cm below the skin surface. The Wi,max was determined during a series of high jumps off both feet on a force platform before and after immersion up to the abdomen for 90 min in a temperature controlled (T = 20 +/- 0.1 degrees C) water bath. Control Tmuscle was 35.8 +/- 0.7 degrees C, with control Wi,max being 51.6 (SD 8.7) W.kg-1. After cold exposure, Tmuscle decreased by about 8 degrees C, whereas wi,max 27% lower. The temperature dependence of Wi,max was found to be less (Q10 less than 1.5, where Q10 is the temperature coefficient as calculated in other studies) than reported in the literature for ATPmax. Such a low Q10 may reflect an increase in the mechanical equivalent of ATP splitting, as a consequence of the reduced velocity of muscle contraction occurring at low Tmuscle.
The exact maximal energy of integral circulant graphs with prime power order
Sander, J W
2011-01-01
The energy of a graph was introduced by {\\sc Gutman} in 1978 as the sum of the absolute values of the eigenvalues of its adjacency matrix. We study the energy of integral circulant graphs, also called gcd graphs, which can be characterized by their vertex count $n$ and a set $\\cal D$ of divisors of $n$ in such a way that they have vertex set $\\mathbb{Z}/n\\mathbb{Z}$ and edge set $\\{\\{a,b\\}:\\, a,b\\in\\mathbb{Z}/n\\mathbb{Z},\\, \\gcd(a-b,n)\\in {\\cal D}\\}$. Given an arbitrary prime power $p^s$, we determine all divisor sets maximising the energy of an integral circulant graph of order $p^s$. This enables us to compute the maximal energy $\\Emax{p^s}$ among all integral circulant graphs of order $p^s$.
The relationship of maximal alactacid anaerobic power to somatotype in trained subjects.
Ergen, E; Sardella, F; Dal Monte, A
1985-12-01
The purpose of the present study was to investigate the relationship between somatotype components and maximal alactacid anaerobic power (MAAP) in trained subjects. The somatotype components (endomorphy: means = 2.66, S.D. = +/- 0.78; mesomorphy: means = 5.45, S.D. = +/- 1.12; ectomorphy: means = 2.46, S.D. = +/- 0.88) and total MAAP were measured in 40 male fencers (aged, means 21.79, S.D. = +/- 3.97) in order to determine the correlations. The results did not show any correlations between the parameters. It can be concluded that the MAAP of an individual does not depend on the somatotype; but it may also be assumed that MAAP show changes with the percentage of fibre type, enzymatic activity in these fibres involved by large muscle groups which are relatively related to musculo-skeletal development (second component of somatotype) and neuro-muscular properties of the subjects, all having a genetic basis.
Dalton, Brian H; Power, Geoffrey A; Paturel, Justin R; Rice, Charles L
2015-06-01
The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque-power relationships were constructed prior to and following both fatiguing tasks and during short-term recovery. Contractile properties were recorded from 9 old (~75 years) and 11 young (~25 years) men during three testing sessions. In the first session, maximal power was assessed, and sessions 2 and 3 involved an isokinetic or an isotonic concentric fatigue task performed until maximal power was reduced by 40 %. Compared with young, the older men performed the same number of contractions to task failure for the isokinetic task (~45 contractions), but 20 % fewer for the isotonic task (p contraction strength, angular velocity, and power were reduced by ~30, ~13, and ~25 %, respectively, immediately following task failure, and only isometric torque was not recovered fully by 10 min. In conclusion, older men are more fatigable than the young when performing a repetitive maximal dynamic task at a relative resistance (isotonic) but not an absolute velocity (isokinetic), corresponding to maximal power.
K. Rajeswari
2015-04-01
Full Text Available A novel hybrid channel estimator is proposed for multiple-input multiple-output orthogonal frequency- division multiplexing (MIMO-OFDM system with per-subcarrier transmit antenna selection having optimal power allocation among subcarriers. In practice, antenna selection information is transmitted through a binary symmetric control channel with a crossover probability. Linear minimum mean-square error (LMMSE technique is optimal technique for channel estimation in MIMO-OFDM system. Though LMMSE estimator performs well at low signal to noise ratio (SNR, in the presence of antenna-to-subcarrier-assignment error (ATSA, it introduces irreducible error at high SNR. We have proved that relaxed MMSE (RMMSE estimator overcomes the performance degradation at high SNR. The proposed hybrid estimator combines the benefits of LMMSE at low SNR and RMMSE estimator at high SNR. The vector mean square error (MSE expression is modified as scalar expression so that an optimal power allocation can be performed. The convex optimization problem is formulated and solved to allocate optimal power to subcarriers minimizing the MSE, subject to transmit sum power constraint. Further, an analytical expression for SNR threshold at which the hybrid estimator is to be switched from LMMSE to RMMSE is derived. The simulation results show that the proposed hybrid estimator gives robust performance, irrespective of ATSA error.
Villadsen, Allan; Roos, Ewa M.; Overgaard, Søren
Abstract : Purpose To evaluate the reliability of single-joint and multi-joint maximal leg muscle power and functional performance measures in patients with severe OA. Background Muscle power, taking both strength and velocity into account, is a more functional measure of lower extremity muscle a...
Roger S Seymour
Full Text Available Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.
Seymour, Roger S
2013-01-01
Inertial homeothermy, the maintenance of a relatively constant body temperature that occurs simply because of large size, is often applied to large dinosaurs. Moreover, biophysical modelling and actual measurements show that large crocodiles can behaviourally achieve body temperatures above 30°C. Therefore it is possible that some dinosaurs could achieve high and stable body temperatures without the high energy cost of typical endotherms. However it is not known whether an ectothermic dinosaur could produce the equivalent amount of muscular power as an endothermic one. To address this question, this study analyses maximal power output from measured aerobic and anaerobic metabolism in burst exercising estuarine crocodiles, Crocodylusporosus, weighing up to 200 kg. These results are compared with similar data from endothermic mammals. A 1 kg crocodile at 30°C produces about 16 watts from aerobic and anaerobic energy sources during the first 10% of exhaustive activity, which is 57% of that expected for a similarly sized mammal. A 200 kg crocodile produces about 400 watts, or only 14% of that for a mammal. Phosphocreatine is a minor energy source, used only in the first seconds of exercise and of similar concentrations in reptiles and mammals. Ectothermic crocodiles lack not only the absolute power for exercise, but also the endurance, that are evident in endothermic mammals. Despite the ability to achieve high and fairly constant body temperatures, therefore, large, ectothermic, crocodile-like dinosaurs would have been competitively inferior to endothermic, mammal-like dinosaurs with high aerobic power. Endothermy in dinosaurs is likely to explain their dominance over mammals in terrestrial ecosystems throughout the Mesozoic.
Crossfit-based high-intensity power training improves maximal aerobic fitness and body composition.
Smith, Michael M; Sommer, Allan J; Starkoff, Brooke E; Devor, Steven T
2013-11-01
The purpose of this study was to examine the effects of a crossfit-based high-intensity power training (HIPT) program on aerobic fitness and body composition. Healthy subjects of both genders (23 men, 20 women) spanning all levels of aerobic fitness and body composition completed 10 weeks of HIPT consisting of lifts such as the squat, deadlift, clean, snatch, and overhead press performed as quickly as possible. Additionally, this crossfit-based HIPT program included skill work for the improvement of traditional Olympic lifts and selected gymnastic exercises. Body fat percentage was estimated using whole-body plethysmography, and maximal aerobic capacity (VO2max) was measured by analyzing expired gasses during a Bruce protocol maximal graded treadmill test. These variables were measured again after 10 weeks of training and compared for significant changes using a paired t-test. Results showed significant (p < 0.05) improvements of VO2max in men (43.10 ± 1.40 to 48.96 ± 1.42 ml · kg · min) and women (35.98 ± 1.60 to 40.22 ± 1.62 ml · kg · min) and decreased body fat percentage in men (22.2 ± 1.3 to 18.0 ± 1.3) and women (26.6 ± 2.0 to 23.2 ± 2.0). These improvements were significant across all levels of initial fitness. Significant correlations between absolute oxygen consumption and oxygen consumption relative to body weight was found in both men (r = 0.83, p < 0.001) and women (r = 0.94, p < 0.001), indicating that HIPT improved VO2max scaled to body weight independent of changes to body composition. Our data show that HIPT significantly improves VO2max and body composition in subjects of both genders across all levels of fitness.
Callaghan, S. A.; Inglis, I.; Hansell, P.
2009-06-01
Adaptive transmit power control (ATPC) can be used to improve the spectrum efficiency of terrestrial point-to-point fixed links by limiting the transmit power to that required to maintain a constant bit error rate regardless of the propagation conditions. This results in a reduced transmit power being used during clear-sky conditions, lowering the interference resulting from the ATPC link. This improves the frequency reuse factor associated with a given band and geographic area, providing a spectrum efficiency gain. The project described in this paper found that implementing ATPC in the 38 GHz terrestrial fixed links band gives significant improvements in spectrum efficiency as measured by the increase in the number of links assigned to channel 1 (from ˜50% to ˜70%) and the decrease in the maximum bandwidth used (from ˜300 MHz to ˜180 MHz). However, a model plan exposed to an exceptionally intense frontal rain event showed a number of additional outages caused by ATPC, amounting to approximately 12% of the number of outages caused directly by rain. In comparison, when exposed to an annualized simulated rain database the number of extra outages in this case falls to 2.6%.
Huang, Jiyan; Liu, Peng; Lin, Wei; Gui, Guan
2016-09-08
The localization of a sensor in wireless sensor networks (WSNs) has now gained considerable attention. Since the transmit power and path loss exponent (PLE) are two critical parameters in the received signal strength (RSS) localization technique, many RSS-based location methods, considering the case that both the transmit power and PLE are unknown, have been proposed in the literature. However, these methods require a search process, and cannot give a closed-form solution to sensor localization. In this paper, a novel RSS localization method with a closed-form solution based on a two-step weighted least squares estimator is proposed for the case with the unknown transmit power and uncertainty in PLE. Furthermore, the complete performance analysis of the proposed method is given in the paper. Both the theoretical variance and Cramer-Rao lower bound (CRLB) are derived. The relationships between the deterministic CRLB and the proposed stochastic CRLB are presented. The paper also proves that the proposed method can reach the stochastic CRLB.
Lillo, F
2006-01-01
I consider the problem of the optimal limit order price of a financial asset in the framework of the maximization of the utility function of the investor. The analytical solution of the problem gives insight on the origin of the recently empirically observed power law distribution of limit order prices. In the framework of the model, the most likely proximate cause of this power law is a power law heterogeneity of traders' investment time horizons .
Quantification of hand and forearm muscle forces during a maximal power grip task.
Goislard de Monsabert, Benjamin; Rossi, Jérémy; Berton, Eric; Vigouroux, Laurent
2012-10-01
The aim of this study was to estimate muscle and joint forces during a power grip task. Considering the actual lack of quantification of such internal variables, this information would be essential for sports sciences, medicine, and ergonomics. This study also contributed to the advancement of scientific knowledge concerning hand control during power grip. A specially designed apparatus combining both an instrumented handle and a pressure map was used to record the forces at the hand/handle interface during maximal exertions. Data were processed such that the forces exerted on 25 hand anatomical areas were determined. Joint angles of the five fingers and the wrist were also computed from synchronized kinematic measurements. These processed data were used as input of a hand/wrist biomechanical model, which includes 23 degrees of freedom and 42 muscles to estimate muscle and joint forces. Greater forces were applied on the distal phalanges of the long fingers compared with the middle and the proximal ones. Concomitantly, high solicitations were observed for FDP muscles. A large cocontraction level of extensor muscles was also estimated by the model and confirmed previously reported activities and injuries of extensor muscles related to the power grip. Quantifying hand internal loadings also resulted in new insights into the thumb and the wrist biomechanics. Output muscle tension ratios were all in smaller ranges than the ones reported in the literature. Including wrist and finger interactions in this hand model provided new quantification of muscle load sharing, cocontraction level, and biomechanics of the hand. Such information could complete future investigations concerning handle ergonomics or pathomechanisms of hand musculoskeletal disorders.
Wilmore, Jack H.; And Others
1986-01-01
Sixty-two subjects completed a four-stage submaximal cycle ergometer test to determine if estimates of maximal oxygen uptake could be improved by using ratings of perceived exertion singly or in combination with easily obtainable physiological measures. These procedures could be used to estimate the aerobic power of patients and athletes. (MT)
Brian H. Dalton; Geoffrey A Power; Paturel, Justin R.; Rice, Charles L.
2015-01-01
The underlying factors related to the divergent findings of age-related fatigue for dynamic tasks are not well understood. The purpose here was to investigate age-related fatigability and recovery between a repeated constrained (isokinetic) and an unconstrained velocity (isotonic) task, in which participants performed fatiguing contractions at the velocity (isokinetic) or resistance (isotonic) corresponding with maximal power. To compare between tasks, isotonic torque–power relationships were...
Thermoelectric power source utilizing ambient energy harvesting for remote sensing and transmitting
DeSteese, John G
2010-11-16
A method and apparatus for providing electrical energy to an electrical device wherein the electrical energy is originally generated from temperature differences in an environment having a first and a second temperature region. A thermoelectric device having a first side and a second side wherein the first side is in communication with a means for transmitting ambient thermal energy collected or rejected in the first temperature region and the second side is in communication with the second temperature region thereby producing a temperature gradient across the thermoelectric device and in turn generating an electrical current.
Furrer, Regula; Jaspers, Richard T.; Baggerman, Hein L.; Bravenboer, Nathalie; Lips, Paul; de Haan, Arnold
2013-01-01
Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM) is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control), peak power training (PT), or both peak power and endurance training (PET), which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training. PMID:23509812
Regula Furrer
2013-01-01
Full Text Available Improvement of muscle peak power and oxidative capacity are generally presumed to be mutually exclusive. However, this may not be valid by using fibre type-specific recruitment. Since rat medial gastrocnemius muscle (GM is composed of high and low oxidative compartments which are recruited task specifically, we hypothesised that the adaptive responses to peak power training were unaffected by additional endurance training. Thirty rats were subjected to either no training (control, peak power training (PT, or both peak power and endurance training (PET, which was performed on a treadmill 5 days per week for 6 weeks. Maximal running velocity increased 13.5% throughout the training and was similar in both training groups. Only after PT, GM maximal force was 10% higher than that of the control group. In the low oxidative compartment, mRNA levels of myostatin and MuRF-1 were higher after PT as compared to those of control and PET groups, respectively. Phospho-S6 ribosomal protein levels remained unchanged, suggesting that the elevated myostatin levels after PT did not inhibit mTOR signalling. In conclusion, even by using task-specific recruitment of the compartmentalized rat GM, additional endurance training interfered with the adaptive response of peak power training and attenuated the increase in maximal force after power training.
Guo, Yi; Jiang, John N; Tang, Choon Yik; Ramakumar, Rama G
2010-01-01
This paper addresses the problem of controlling a variable-speed wind turbine with a Doubly Fed Induction Generator (DFIG), modeled as an electromechanically-coupled nonlinear system with rotor voltages and blade pitch angle as its inputs, active and reactive powers as its outputs, and most of the aerodynamic and mechanical parameters as its uncertainties. Using a blend of linear and nonlinear control strategies (including feedback linearization, pole placement, uncertainty estimation, and gradient-based potential function minimization) as well as time-scale separation in the dynamics, we develop a controller that is capable of maximizing the active power in the Maximum Power Tracking (MPT) mode, regulating the active power in the Power Regulation (PR) mode, seamlessly switching between the two modes, and simultaneously adjusting the reactive power to achieve a desired power factor. The controller consists of four cascaded components, uses realistic feedback signals, and operates without knowledge of the C_p-...
Park, Kihong
2011-01-01
In this paper, we consider multicarrier systems with multiple transmit antennas under a power-balancing constraint. Applying transmit antenna selection and discrete rate-adaptive modulation using M-ary quadrature-amplitude modulation (QAM) according to the channel variation per subcarrier, we develop an optimal transmit antenna selection scheme in terms of the maximum spectral efficiency, where all the possible groupings for sending the same information-bearing signals in a group of subcarriers are searched, and the groups of subcarriers for providing the frequency diversity gain are formed. In addition, we propose a suboptimal method for reducing the computational complexity of the optimal method. The suboptimal scheme considers only the subcarriers under outage, and these subcarriers are sequentially combined until the required signal-to-noise ratio (SNR) is met. Numerical results show that the proposed suboptimal method with diversity combining outperforms the optimal antenna selection without diversity combining, as introduced in the work of Sandell and Coon, particularly for low-SNR regions, and offers the spectral efficiency close to the optimal method with diversity combining while maintaining lower complexity. © 2011 IEEE.
Benefits of active transmit balanced antenna fed by differential power amplifier
Sagor, Md. Hasanuzzaman; Callaghan, Peter
2014-01-01
A differential amplifier feeding a balanced antenna is investigated experimentally. This approach would suit modern RFIC design rather than using a 50Ω unbalanced connection. As such the balun or power-combining network is eliminated resulting in a compact RF front-end design with wider bandwidth and lower losses. Experimental result shows that this technique promises higher output power compared to conventional feeding approach while using same RFIC and same power supply.
Coggan, Andrew R; Leibowitz, Joshua L; Kadkhodayan, Ana; Thomas, Deepak P; Ramamurthy, Sujata; Spearie, Catherine Anderson; Waller, Suzanne; Farmer, Marsha; Peterson, Linda R
2015-08-01
Nitric oxide (NO) has been demonstrated to enhance the maximal shortening velocity and maximal power of rodent muscle. Dietary nitrate (NO3(-)) intake has been demonstrated to increase NO bioavailability in humans. We therefore hypothesized that acute dietary NO3(-) intake (in the form of a concentrated beetroot juice (BRJ) supplement) would improve muscle speed and power in humans. To test this hypothesis, healthy men and women (n = 12; age = 22-50 y) were studied using a randomized, double-blind, placebo-controlled crossover design. After an overnight fast, subjects ingested 140 mL of BRJ either containing or devoid of 11.2 mmol of NO3(-). After 2 h, knee extensor contractile function was assessed using a Biodex 4 isokinetic dynamometer. Breath NO levels were also measured periodically using a Niox Mino analyzer as a biomarker of whole-body NO production. No significant changes in breath NO were observed in the placebo trial, whereas breath NO rose by 61% (P power at the highest angular velocity tested (i.e., 6.28 rad/s). Calculated maximal knee extensor power was therefore greater (i.e., 7.90 ± 0.59 vs. 7.44 ± 0.53 W/kg; P power in healthy men and women.
Ro, Kyoungsoo
The study started with the requirement that a photovoltaic (PV) power source should be integrated with other supplementary power sources whether it operates in a stand-alone or grid-connected mode. First, fuel cells for a backup of varying PV power were compared in detail with batteries and were found to have more operational benefits. Next, maximizing performance of a grid-connected PV-fuel cell hybrid system by use of a two-loop controller was discussed. One loop is a neural network controller for maximum power point tracking, which extracts maximum available solar power from PV arrays under varying conditions of insolation, temperature, and system load. A real/reactive power controller (RRPC) is the other loop. The RRPC meets the system's requirement for real and reactive powers by controlling incoming fuel to fuel cell stacks as well as switching control signals to a power conditioning subsystem. The RRPC is able to achieve more versatile control of real/reactive powers than the conventional power sources since the hybrid power plant does not contain any rotating mass. Results of time-domain simulations prove not only effectiveness of the proposed computer models of the two-loop controller, but also their applicability for use in transient stability analysis of the hybrid power plant. Finally, environmental evaluation of the proposed hybrid plant was made in terms of plant's land requirement and lifetime COsb2 emissions, and then compared with that of the conventional fossil-fuel power generating forms.
Maximization of ICRF power by SOL density tailoring with local gas injection
Jacquet, P.; Goniche, M.; Bobkov, V.; Lerche, E.; Pinsker, R. I.; Pitts, R. A.; Zhang, W.; Colas, L.; Hosea, J.; Moriyama, S.; Wang, S.-J.; Wukitch, S.; Zhang, X.; Bilato, R.; Bufferand, H.; Guimarais, L.; Faugel, H.; Hanson, G. R.; Kocan, M.; Monakhov, I.; Noterdaeme, J.-M.; Petrzilka, V.; Shaw, A.; Stepanov, I.; Sips, A. C. C.; Van Eester, D.; Wauters, T.; JET contributors, the; the ASDEX Upgrade Team; the DIII-D Team; ITPA ‘Integrated Operation Scenarios' members, the; experts
2016-04-01
Experiments have been performed under the coordination of the International Tokamak Physics Activity (ITPA) on several tokamaks, including ASDEX Upgrade (AUG), JET and DIII-D, to characterize the increased Ion cyclotron range of frequency (ICRF) antenna loading achieved by optimizing the position of gas injection relative to the RF antennas. On DIII-D, AUG and JET (with the ITER-Like Wall) a 50% increase in the antenna loading was observed when injecting deuterium in ELMy H-mode plasmas using mid-plane inlets close to the powered antennas instead of divertor injection and, with smaller improvement when using gas inlets located at the top of the machine. The gas injection rate required for such improvements (~0.7 × 1022 el s-1 in AUG, ~1.0 × 1022 el s-1 in JET) is compatible with the use of this technique to optimize ICRF heating during the development of plasma scenarios and no degradation of confinement was observed when using the mid-plane or top inlets compared with divertor valves. An increase in the scrape-off layer (SOL) density was measured when switching gas injection from divertor to outer mid-plane or top. On JET and DIII-D, the measured SOL density increase when using main chamber puffing is consistent with the antenna coupling resistance increase provided that the distance between the measurement lines of sight and the injection location is taken into account. Optimized gas injection was also found to be beneficial for reducing tungsten (W) sputtering at the AUG antenna limiters, and also to reduce slightly the W and nickel (Ni) content in JET plasmas. Modeling the specific effects of divertor/top/mid-plane injection on the outer mid-plane density was carried out using both the EDGE2D-EIRENE and EMC3-EIRENE plasma boundary code packages; simulations indeed indicate that outer mid-plane gas injection maximizes the density in the mid-plane close to the injection point with qualitative agreement with the AUG SOL density measurements
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
Blaszczyk, Tomasz; Lynggaard, Per
2016-01-01
— A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
Lynggaard, P.; Blaszczyk, Tomasz
2016-01-01
A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
Lynggaard, P.; Blaszczyk, Tomasz
2016-01-01
A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks....
Driss, Tarak; Lambertz, Daniel; Rouis, Majdi; Vandewalle, Henry
2012-11-01
The importance of maximal voluntary torque (T (MVC)), maximal rate of torque development (MRTD) and musculo-tendinous stiffness of the triceps surae for maximal power output on a cycle ergometre (Pmax) was studied in 21 healthy subjects by studying the relationships between maximal cycling power related to body mass (Pmax BM(-1)) with T (MVC), MRTD and different indices of musculo-tendinous stiffness of the ankle flexor. Pmax BM(-1) was calculated from the data of an all-out force-velocity test on a Monark cycle ergometre. T (MVC) and MRTD were measured on a specific ankle ergometre. Musculo-tendinous stiffness was estimated by means of quick releases at 20, 40, 60 and 80% T (MVC) on the same ankle ergometre. Pmax BM(-1) was significantly and positively correlated with MRTD related to body mass but the positive correlation between Pmax BM(-1) and T (MVC) did not reach the significance level (0.05). Pmax BM(-1) was significantly and positively correlated with the estimation of stiffness at 40% T (MVC) (S(0.4)), but not with stiffness at 20, 60 and 80% T (MVC). The results of the present study suggest that maximal power output during cycling is significantly correlated with the level of musculo-tendinous stiffness which corresponds to torque range around peak torque at optimal pedal rate. However, the low coefficient of determination (r2 = 0.203) between Pmax BM(-1) and S (0.4) BM(-1) suggested that Pmax BM(-1) largely depended on other factors than the musculo-tendinous stiffness of the only plantar flexors.
An Energy-Efficient Link with Adaptive Transmit Power Control for Long Range Networks
Lynggaard, Per; Blaszczyk, tomasz
2016-01-01
— A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes and ...... and algorithms which are essential for deployment of wireless IoT nodes. This paper presents an adaptive link algorithm for farm applications with emphasis on power adjustment for long range communication networks.......— A considerable amount of research is carried out to develop a reliable smart sensor system with high energy efficiency for battery operated wireless IoT devices in the agriculture sector. However, only a limited amount of research has covered automatic transmission power adjustment schemes...
侯婷婷; 娄素华; 张滋华; 吴耀武
2012-01-01
针对风电基地风电外送的形势,提出了一种风电汇聚外送配套火电容量优化方法。针对风电的随机性,定义了输电通道的持续STC曲线,来分析输电通道输送风电后火电可用容量空间的特性。在此基础上,建立了风电外送配套火电容量优化模型,模型考虑了输电线路、配套火电的费用及输送电量收益,在风电优先外送的前提下,充分利用输电通道,使得经济效益最大化,并采用两层优化策略对模型进行求解。应用本文模型对一个算例系统进行了计算分析,并对电价和火电煤价对结果的影响进行了分析,结果证明了所提方法的正确性和有效性。%ince wind power is explored on a large scale and in a highly centralized way these years,and usually wind bases are inconsistent with load in geographic region,so transmitting wind power through high-voltage transmission line will be an inevitable trend.In this new situation,the paper presents an optimal methodology for corollary thermal sources transmitted with wind power together for wind power’s variability and low energy density.For the random nature of wind power,the duration curve of spare capacity of transmission line(STC) which can be used to transmit thermal power is introduced to illustrate characteristics of capacity for thermal power after transmitting wind power.Based on the duration curve of STC,the model for optimizing the capacity of corollary thermal sources is proposed,which takes into account transmission line costs,thermal sources costs and benefit of electric power transmitted,and the objective function being maximized is the total benefits.The model can be solved by a two-stage optimal strategy.The case studies are carried out for a system,where effects of coal price and electricity price on the optimal schemes is also studied,and the results verify the effectiveness of the presented method.
Time-domain clustered transmit power adaptation for OFDM system in fading channels
GAN Xiao-ying; XU You-yun; GUAN Yun-feng; SONG Wen-tao
2006-01-01
This paper proposes a time-domain clustered transmitter power adaptation scheme for orthogonal frequency division multiplexing (OFDM) system, which can significantly reduce the feedback amount during power adaptation comparison with conventional frequency-domain adaptation schemes. It was found that the cluster size plays an important role on the adaptation performance, especially for the vehicular environment. Simulation results showed that using Lagrange interpolation to obtain an explicit curve of Doppler frequency vs cluster size yields good trade-offbetween the resulted bit error rate (BER) and the amount of feedback.
Bianba, B; Berntsen, S; Andersen, Lars Bo
2010-01-01
Chinese children aged 9-10 years, living in Lhasa at 3700 meters above sea level, V.O2peak was measured directly using a portable oxygen analyzer, and predicted from maximal power output (Wmax) using a maximal cycle ergometer test. RESULTS: In multiple regression analyses with V.O2peak as dependent......AIM: The aims of the present study of Tibetan and Han Chinese children were to establish prediction equations for peak oxygen uptake (V.O2peak) using conventional power output measures, and to compare with prediction models based on data from sea level. METHODS: In 25 Tibetan children and 15 Han...... with the equations from the present study. None of the three could accurately predict the direct measured V.O2peak, and predictions differed in an unsystematic manner, including over- or underestimation and no differentiation between genders. CONCLUSION: Peak oxygen uptake could be estimated from Wmax and sex...
Maximization of revenues for power sales from a solid waste resources recovery facility
1991-12-01
The report discusses the actual implementation of the best alternative in selling electrical power generated by an existing waste-to-energy facility, the Metro-Dade County Resources Recovery Plant. After the plant processes and extracts various products out of the municipal solid waste, it burns it to produce electrical power. The price for buying power to satisfy the internal needs of our Resources Recovery Facility (RRF) is substantially higher than the power price for selling electricity to any other entity. Therefore, without any further analysis, it was decided to first satisfy those internal needs and then export the excess power. Various alternatives were thoroughly explored as to what to do with the excess power. Selling power to the power utilities or utilizing the power in other facilities were the primary options.
Vandewalle, H; Peres, G; Heller, J; Panel, J; Monod, H
1987-01-01
The force-velocity relationship on a Monark ergometer and the vertical jump height have been studied in 152 subjects practicing different athletic activities (sprint and endurance running, cycling on track and/or road, soccer, rugby, tennis and hockey) at an average or an elite level. There was an approximately linear relationship between braking force and peak velocity for velocities between 100 and 200 rev.min-1. The highest indices of force P0, velocity V0 and maximal anaerobic power (Wmax) were observed in the power athletes. There was a significant relationship between vertical jump height and Wmax related to body mass.
The power spectral density of digital modulations transmitted over nonlinear channels
Divsalar, D.; Simon, M. K.
1982-01-01
This paper examines by analytical methods the power spectral densities of digital modulations (in particular, staggered and unstaggered quadrature modulations) passed through band-limited nonlinear channels. Previously observed (by computer simulation or hardware measurement) behavior of such spectra with regard to the suppression or restoration of its sidelobes after passing through the nonlinearity is verified analytically. Several examples corresponding to specific quadrature modulations and filter-nonlinearity combinations are presented as illustrations of the general results.
Yasuhiro Tsubo
Full Text Available The brain is considered to use a relatively small amount of energy for its efficient information processing. Under a severe restriction on the energy consumption, the maximization of mutual information (MMI, which is adequate for designing artificial processing machines, may not suit for the brain. The MMI attempts to send information as accurate as possible and this usually requires a sufficient energy supply for establishing clearly discretized communication bands. Here, we derive an alternative hypothesis for neural code from the neuronal activities recorded juxtacellularly in the sensorimotor cortex of behaving rats. Our hypothesis states that in vivo cortical neurons maximize the entropy of neuronal firing under two constraints, one limiting the energy consumption (as assumed previously and one restricting the uncertainty in output spike sequences at given firing rate. Thus, the conditional maximization of firing-rate entropy (CMFE solves a tradeoff between the energy cost and noise in neuronal response. In short, the CMFE sends a rich variety of information through broader communication bands (i.e., widely distributed firing rates at the cost of accuracy. We demonstrate that the CMFE is reflected in the long-tailed, typically power law, distributions of inter-spike intervals obtained for the majority of recorded neurons. In other words, the power-law tails are more consistent with the CMFE rather than the MMI. Thus, we propose the mathematical principle by which cortical neurons may represent information about synaptic input into their output spike trains.
Zhang, Baohua; Hu, Weihao; Hou, Peng;
2016-01-01
The energy loss in a wind farm (WF) caused by wake interaction between wind turbines (WTs) is quite high, which can be reduced by proper active power dispatch. The electrical loss inside a WF by improper active power and reactive power dispatch is also considerable. In this paper, a coordinated a...
Kazemi, A.; Hosseinipoor, N.A. [Iran Univ. of Science and Technology, Tehran (Iran, Islamic Republic of)
2010-07-01
A series FACTS device such as a thyristor controlled series compensator (TCSC) has the ability to directly control the power flow and can be effective in improving the operation of a transmission network. This paper examined the optimal locating and sizing of a TCSC, for congestion management in competitive power markets. It proposed an algorithm for congestion management based on an optimal power flow (OPF) framework. The paper discussed the TCSC model and described the proposed method and formulation of an OPF framework. It was solved with the objective function of maximizing the social welfare by using a genetic algorithm for optimal fine-tuning generation and loads schedule and location-sizing of one unit TCSC. The simulation results were tested on the IEEE 14-bus and IEEE 30-bus system. It was validated through comparison of obtained social welfare with and without TCSC. It was concluded that this device was appropriate for long-term congestion management. 12 refs., 5 tabs.
Alsharoa, Ahmad M.
2014-02-01
In this letter, we consider a multiple-input multiple-output two-way cognitive radio system under a spectrum sharing scenario, where primary and secondary users operate on the same frequency band. The secondary terminals aims to exchange different messages with each other using multiple relays where each relay employs an amplify-and-forward strategy. The main objective of our work is to maximize the secondary sum rate allowed to share the spectrum with the primary users by respecting a primary user tolerated interference threshold. In this context, we derive an analytical expression of the optimal power allocated to each antenna of the terminals. We then discuss the impact of some system parameters on the performance in the numerical result section. © 2012 IEEE.
da Silva, Bruno Victor C; Simim, Mário A de Moura; Marocolo, Moacir; Franchini, Emerson; da Mota, Gustavo R
2015-06-01
We determined the optimal load for the peak power output (PPO) during the bench press throw (BPT) in Brazilian Jiu-Jitsu (BJJ) athletes and compared the PPO and maximal strength between advanced (AD) and nonadvanced (NA) athletes. Twenty-eight BJJ athletes (24.8 ± 5.7 years) performed the BPT at loads of 30, 40, 50, and 60% of their 1 repetition maximum (RM) in a randomized order (5-minute rest between BPTs). The PPO was determined by measuring the barbell displacement by an accelerometer (Myotest). The absolute (F = 7.25; p 0.05) in the PPO (30-60% 1RM). A polynomial adjustment indicated that the optimal load was ∼42% of 1RM for all groups and subgroups (R from 0.82 to 0.99). Our results suggest that there can be (1RM) differences between AD and NA BJJ athletes; however, there is no difference in the muscle power between the AD and NA groups. Additionally, ∼42% of 1RM seems to be the optimal load for developing maximal power using the BPT for the BJJ athletes.
Maximizing the power density of aqueous electrochemical flow cells with in operando deposition
Goulet, Marc-Antoni; Ibrahim, Omar A.; Kim, Will H. J.; Kjeang, Erik
2017-01-01
To transition toward sustainable energy systems, next generation power sources must provide high power density at minimum cost. Using inexpensive and environmentally friendly fabrication methods, this work describes a room temperature electrochemical flow cell with a maximum power density of 2.01 W cm-2 or 13.4 W cm-3. In part, this is achieved by minimizing ohmic resistance through decreased electrode spacing, implementation of current collectors and improvement of electrolyte conductivity. The majority of the performance gain is provided by a novel in operando dynamic flowing deposition method for which the cell design has been optimized. Carbon nanotubes (CNTs) are deposited dynamically at the entrance of and within the carbon paper electrodes during operation of the cell. A natural equilibrium is reached between deposition and detachment of CNTs at which the electrochemical surface area and pore size distribution of the flow-through porous electrodes are greatly enhanced. In this way, the novel deposition method more than doubles the power density of the cell and sets a new performance benchmark for what is practically attainable with aqueous electrochemical flow cells. Overall, it is expected that the design and operation methods illustrated here will enable a wide range of electrochemical flow cell technologies to achieve optimal performance.
Ghazzai, Hakim
2016-03-15
High-speed railway system equipped with moving relay stations placed on the middle of the ceiling of each train wagon is investigated. The users inside the train are served in two hops via the orthogonal frequency-division multiple access (OFDMA) technology. In this work, we first focus on minimizing the total downlink power consumption of the base station (BS) and the moving relays while respecting specific quality of service (QoS) constraints. We first derive the optimal resource allocation solution in terms of OFDMA subcarriers and power allocation using the dual decomposition method. Then, we propose an efficient algorithm based on the Hungarian method in order to find a suboptimal but low complexity solution. Moreover, we propose an OFDMA planning solution for high-speed train by finding the maximal inter-BS distance given the required user data rates in order to perform seamless handover. Our simulation results illustrate the performance of the proposed resource allocation schemes in the case of the 3GPP Long Term Evolution-Advanced (LTE-A) and compare them with previously developed algorithms as well as with the direct transmission scenario. Our results also highlight the significant planning gain obtained thanks to the use of multiple relays instead of the conventional single relay scenario.
Habibi, Hamed; Rahimi Nohooji, Hamed; Howard, Ian
2017-09-01
Power maximization has always been a practical consideration in wind turbines. The question of how to address optimal power capture, especially when the system dynamics are nonlinear and the actuators are subject to unknown faults, is significant. This paper studies the control methodology for variable-speed variable-pitch wind turbines including the effects of uncertain nonlinear dynamics, system fault uncertainties, and unknown external disturbances. The nonlinear model of the wind turbine is presented, and the problem of maximizing extracted energy is formulated by designing the optimal desired states. With the known system, a model-based nonlinear controller is designed; then, to handle uncertainties, the unknown nonlinearities of the wind turbine are estimated by utilizing radial basis function neural networks. The adaptive neural fault tolerant control is designed passively to be robust on model uncertainties, disturbances including wind speed and model noises, and completely unknown actuator faults including generator torque and pitch actuator torque. The Lyapunov direct method is employed to prove that the closed-loop system is uniformly bounded. Simulation studies are performed to verify the effectiveness of the proposed method.
Habibi, Hamed; Rahimi Nohooji, Hamed; Howard, Ian
2017-04-01
Power maximization has always been a practical consideration in wind turbines. The question of how to address optimal power capture, especially when the system dynamics are nonlinear and the actuators are subject to unknown faults, is significant. This paper studies the control methodology for variable-speed variable-pitch wind turbines including the effects of uncertain nonlinear dynamics, system fault uncertainties, and unknown external disturbances. The nonlinear model of the wind turbine is presented, and the problem of maximizing extracted energy is formulated by designing the optimal desired states. With the known system, a model-based nonlinear controller is designed; then, to handle uncertainties, the unknown nonlinearities of the wind turbine are estimated by utilizing radial basis function neural networks. The adaptive neural fault tolerant control is designed passively to be robust on model uncertainties, disturbances including wind speed and model noises, and completely unknown actuator faults including generator torque and pitch actuator torque. The Lyapunov direct method is employed to prove that the closed-loop system is uniformly bounded. Simulation studies are performed to verify the effectiveness of the proposed method.
Bianba, B; Berntsen, S; Andersen, Lars Bo;
2010-01-01
in a progressive cycle ergometer test among children living at 3700 meters in Tibet. The estimate of V.O2peak is probably more valid using the present equations than prediction models based on data from sea level. The equations used for the prediction are: BianbaeqT: (l·min-1) = 0.5419 + (0.0096· Wmax) - (0...... Chinese children aged 9-10 years, living in Lhasa at 3700 meters above sea level, V.O2peak was measured directly using a portable oxygen analyzer, and predicted from maximal power output (Wmax) using a maximal cycle ergometer test. RESULTS: In multiple regression analyses with V.O2peak as dependent......AIM: The aims of the present study of Tibetan and Han Chinese children were to establish prediction equations for peak oxygen uptake (V.O2peak) using conventional power output measures, and to compare with prediction models based on data from sea level. METHODS: In 25 Tibetan children and 15 Han...
Self-suspended vibration-driven energy harvesting chip for power density maximization
Murillo, Gonzalo; Agustí, Jordi; Abadal, Gabriel
2015-11-01
This work introduces a new concept to integrate energy-harvesting devices with the aim of improving their throughput, mainly in terms of scavenged energy density and frequency tunability. This concept, named energy harvester in package (EHiP), is focused on the heterogeneous integration of a MEMS die, dedicated to scavenging energy, with an auxiliary chip, which can include the control and power management circuitry, sensors and RF transmission capabilities. The main advantages are that the whole die can be used as an inertial mass and the chip area usage is optimized. Based on this concept, in this paper we describe the development and characterization of a MEMS die fully dedicated to harvesting mechanical energy from ambient vibrations through an electrostatic transduction. A test PCB has been fabricated to perform the assembly that allows measurement of the resonance motion of the whole system at 289 Hz. An estimated maximum generated power of around 11 μW has been obtained for an input vibration acceleration of ˜10 m s-2 when the energy harvester operates in a constant-charge cycle for the best-case scenario. Therefore, a maximum scavenged power density of 0.85 mW cm-3 is theoretically expected for the assembled system. These results demonstrate that the generated power density of any vibration-based energy harvester can be significantly increased by applying the EHiP concept, which could become an industrial standard for manufacturing this kind of system, independently of the transduction type, fabrication technology or application.
Zhang, Baohua; Hu, Weihao; Hou, Peng
2015-01-01
Inclusion of the wake effect in the wind farm control design (WF) can increase the total captured power by wind turbines (WTs), which is usually implemented by derating upwind WTs. However, derating the WT without a proper control strategy will increase the structural loads, caused by operation i...
Maximal Force Characteristics of the Ca2+-Powered Actuator of Vorticella convallaria
Ryu, Sangjin; Lang, Matthew J.; Matsudaira, Paul
2012-01-01
The millisecond stalk contraction of the sessile ciliate Vorticella convallaria is powered by energy from Ca2+ binding to generate contractile forces of ∼10 nN. Its contractile organelle, the spasmoneme, generates higher contractile force under increased stall resistances. By applying viscous drag force to contracting V. convallaria in a microfluidic channel, we observed that the mechanical force and work of the spasmoneme depended on the stalk length, i.e., the maximum tension (150–350 nN) a...
Least cost addition of power from hydroelectrical developments: Maximizing existing assets
Felix, Lafontant; Briand, Marie-Helene; Veilleux, Rheaume
2010-09-15
Hydroelectric developments built in the early 1900's are nearing their useful lifespan and require significant rehabilitation in order to meet modern safety and performance criteria. Also, global increasing energy costs represent a strong incentive for operators to find low-cost, environment-friendly solutions while increasing energy generation at existing facilities. Projects promoting innovative ways of recycling existing developments are great examples of sustainable development and represent win-win solutions for population and hydropower industry alike. The proposed presentation describes successful projects consisting in the rehabilitation or addition of power to existing hydroelectric. These recycling projects are very attractive from both economic and environmental.
Lee, Wonje; Boskamp, Eddy; Grist, Thomas; Kurpad, Krishna
2009-07-01
A radiofrequency current source (RFCS) design using a high-power metal oxide semiconductor field effect transistor (MOSFET) that enables independent current control for parallel transmit applications is presented. The design of an RFCS integrated with a series tuned transmitting loop and its associated control circuitry is described. The current source is operated in a gated class AB push-pull configuration for linear operation at high efficiency. The pulsed RF current amplitude driven into the low impedance transmitting loop was found to be relatively insensitive to the various loaded loop impedances ranging from 0.4 to 10.3 ohms, confirming current mode operation. The suppression of current induced by a neighboring loop was quantified as a function of center-to-center loop distance, and was measured to be 17 dB for nonoverlapping, adjacent loops. Deterministic manipulation of the B(1) field pattern was demonstrated by the independent control of RF phase and amplitude in a head-sized two-channel volume transmit array. It was found that a high-voltage rated RF power MOSFET with a minimum load resistance, exhibits current source behavior, which aids in transmit array design.
2012-12-01
portable devices where system size and efficiency are the primary design factors. Size and efficiency also govern the use of multiple MPPTs at the sub... mechanisms responsible for the energy losses in a switch-mode converter are the same. They include the components responsible for conduction, capacitor...designed to directly power a load as done in this test. The SPV-1020 may require an appropriate battery charger such as the STEVAL SEA05 battery
Maximal force characteristics of the Ca(2+)-powered actuator of Vorticella convallaria.
Ryu, Sangjin; Lang, Matthew J; Matsudaira, Paul
2012-09-05
The millisecond stalk contraction of the sessile ciliate Vorticella convallaria is powered by energy from Ca(2+) binding to generate contractile forces of ∼10 nN. Its contractile organelle, the spasmoneme, generates higher contractile force under increased stall resistances. By applying viscous drag force to contracting V. convallaria in a microfluidic channel, we observed that the mechanical force and work of the spasmoneme depended on the stalk length, i.e., the maximum tension (150-350 nN) and work linearly depended on the stalk length (∼2.5 nN and ∼30 fJ per 1 μm of the stalk). This stalk-length dependency suggests that motor units of the spasmoneme may be organized in such a way that the mechanical force and work of each unit cumulate in series along the spasmoneme.
Effect of Carbohydrate Intake on Maximal Power Output and Cognitive Performances
Laura Pomportes
2016-10-01
Full Text Available The present study aimed to assess the beneficial effect of acute carbohydrate (7% CHO intake on muscular and cognitive performances. Seventeen high levels athletes in explosive sports (fencing and squash participated in a randomized, double-blind study consisting in series of 6 sprints (5s with a passive recovery (25s followed by 15 min submaximal cycling after either maltodextrine and fructose (CHO or placebo (Pl intake. Cognitive performances were assessed before and after sprint exercise using a simple reaction time (SRT task at rest, a visual scanning task (VS and a Go/Nogo task (GNG during a submaximal cycling exercise. Results showed a beneficial effect of exercise on VS task on both conditions (Pl: −283 ms; CHO: −423 ms and on SRT only during CHO condition (−26 ms. In the CHO condition, SRT was faster after exercise whereas no effect of exercise was observed in the Pl condition. According to a qualitative statistical method, a most likely and likely positive effect of CHO was respectively observed on peak power (+4% and tiredness (−23% when compared to Pl. Furthermore, a very likely positive effect of CHO was observed on SRT (−8% and a likely positive effect on visual scanning (−6% and Go/Nogo tasks (−4% without any change in accuracy. In conclusion acute ingestion of 250 mL of CHO, 60 min and 30 min before exercise, improve peak power output, decrease muscular tiredness and speed up information processing and visual detection without changing accuracy.
Garbouj, H; Selmi, M A; Sassi, R Haj; Yahmed, M Haj; Chamari, K; Chaouachi, A
2016-12-01
The Special Judo Fitness Test (SJFT) has become the test most widely used by coaches and physical trainers for assessment of competitors' judo-specific physical aptitude and training programme prescription. The aim of this study was to investigate the relationship between the SJFT performance indices and both maximal aerobic power and the level of blood lactate concentrations in female judo athletes. Seventeen female judokas (age: 21.9±1.6 years, body mass: 74.6±27.4 kg, height: 164.5±8.6 cm; BMI: 27.1±8.0 kg · m(-2)) took part in this study. All participants performed the SJFT, 20 m multi-stage shuttle run test (MSRT), and 30 m straight sprint test (SST), from which we calculated both acceleration (10 m) and the maximal anaerobic speed (MAnS: flying 20 m sprint). A blood sample was taken 3 min after the SJFT. The number of throws was significantly correlated with estimated VO2max (r=0.795, p=0.0001) and both acceleration (r=0.63, p =0.006) and MAnS (r=0.76, p=0.0004). Peak blood lactate recorded after the SJFT was 13.90±1.39 mmol · l(-1). No significant correlation was found between blood lactate concentration and the SJFT performance indices. The lack of significant correlation between blood lactate and SJFT performance suggests that lactic anaerobic metabolism has no effect on this type of judo-specific supra-maximal exercise. The observed results can provide coaches and strength and conditioning professionals with relevant information for the interpretation of SJFT performance and the prescription of specific training programmes for female judo athletes.
Mahdi M. M. El-Arini
2013-01-01
Full Text Available In recent years, the solar energy has become one of the most important alternative sources of electric energy, so it is important to operate photovoltaic (PV panel at the optimal point to obtain the possible maximum efficiency. This paper presents a new optimization approach to maximize the electrical power of a PV panel. The technique which is based on objective function represents the output power of the PV panel and constraints, equality and inequality. First the dummy variables that have effect on the output power are classified into two categories: dependent and independent. The proposed approach is a multistage one as the genetic algorithm, GA, is used to obtain the best initial population at optimal solution and this initial population is fed to Lagrange multiplier algorithm (LM, then a comparison between the two algorithms, GA and LM, is performed. The proposed technique is applied to solar radiation measured at Helwan city at latitude 29.87°, Egypt. The results showed that the proposed technique is applicable.
Singh, Brijesh; Mahanty, Ranjit; Singh, S. P.
2013-05-01
This paper presents a framework to achieve an optimal power flow solution in a decentralized bilateral multitransaction-based market. An independent optimal dispatch solution has been used for each market. The interior point (IP)-based optimization technique has been used for finding a global economic optimal solution of the whole system. In this method, all the participants try to maximize their own profits with the help of system information announced by the operator. In the present work, a parallel algorithm has been used to find out a global optimum solution in decentralized market model. The study has been carried out on a modified IEEE-30 bus system. The results show that the suggested decentralized approach can provide a better optimal solution. The obtained results show the effectiveness of IP optimization-based optimal generator schedule and congestion management in the decentralized market.
Rudiger Bubner
1998-12-01
Full Text Available Even though the maxims' theory is not at thecenter of Kant's ethics, it is the unavoidable basis of the categoric imperative's formulation. Kant leanson the transmitted representations of modem moral theory. During the last decades, the notion of maxims has deserved more attention, due to the philosophy of language's debates on rules, and due to action theory's interest in this notion. I here by brietly expound my views in these discussions.
Wang, Guiji; Chen, Xuemiao; Cai, Jintao; Zhang, Xuping; Chong, Tao; Luo, Binqiang; Zhao, Jianheng; Sun, Chengwei; Tan, Fuli; Liu, Cangli; Wu, Gang
2016-06-01
A high current pulsed power generator CQ-3-MMAF (Multi-Modules Assembly Facility, MMAF) was developed for material dynamics experiments under ramp wave and shock loadings at the Institute of Fluid Physics (IFP), which can deliver 3 MA peak current to a strip-line load. The rise time of the current is 470 ns (10%-90%). Different from the previous CQ-4 at IFP, the CQ-3-MMAF energy is transmitted by hundreds of co-axial high voltage cables with a low impedance of 18.6 mΩ and low loss, and then hundreds of cables are reduced and converted to tens of cables into a vacuum chamber by a cable connector, and connected with a pair of parallel metallic plates insulated by Kapton films. It is composed of 32 capacitor and switch modules in parallel. The electrical parameters in short circuit are with a capacitance of 19.2 μF, an inductance of 11.7 nH, a resistance of 4.3 mΩ, and working charging voltage of 60 kV-90 kV. It can be run safely and stable when charged from 60 kV to 90 kV. The vacuum of loading chamber can be up to 10-2 Pa, and the current waveforms can be shaped by discharging in time sequences of four groups of capacitor and switch modules. CQ-3-MMAF is an adaptive machine with lower maintenance because of its modularization design. The COMSOL Multi-physics® code is used to optimize the structure of some key components and calculate their structural inductance for designs, such as gas switches and cable connectors. Some ramp wave loading experiments were conducted to check and examine the performances of CQ-3-MMAF. Two copper flyer plates were accelerated to about 3.5 km/s in one shot when the working voltage was charged to 70 kV. The velocity histories agree very well. The dynamic experiments of some polymer bonded explosives and phase transition of tin under ramp wave loadings were also conducted. The experimental data show that CQ-3-MMAF can be used to do material dynamics experiments in high rate and low cost shots. Based on this design concept, the peak
Wang, Guiji; Chen, Xuemiao; Cai, Jintao; Zhang, Xuping; Chong, Tao; Luo, Binqiang; Zhao, Jianheng; Sun, Chengwei; Tan, Fuli; Liu, Cangli; Wu, Gang
2016-06-01
A high current pulsed power generator CQ-3-MMAF (Multi-Modules Assembly Facility, MMAF) was developed for material dynamics experiments under ramp wave and shock loadings at the Institute of Fluid Physics (IFP), which can deliver 3 MA peak current to a strip-line load. The rise time of the current is 470 ns (10%-90%). Different from the previous CQ-4 at IFP, the CQ-3-MMAF energy is transmitted by hundreds of co-axial high voltage cables with a low impedance of 18.6 mΩ and low loss, and then hundreds of cables are reduced and converted to tens of cables into a vacuum chamber by a cable connector, and connected with a pair of parallel metallic plates insulated by Kapton films. It is composed of 32 capacitor and switch modules in parallel. The electrical parameters in short circuit are with a capacitance of 19.2 μF, an inductance of 11.7 nH, a resistance of 4.3 mΩ, and working charging voltage of 60 kV-90 kV. It can be run safely and stable when charged from 60 kV to 90 kV. The vacuum of loading chamber can be up to 10(-2) Pa, and the current waveforms can be shaped by discharging in time sequences of four groups of capacitor and switch modules. CQ-3-MMAF is an adaptive machine with lower maintenance because of its modularization design. The COMSOL Multi-physics® code is used to optimize the structure of some key components and calculate their structural inductance for designs, such as gas switches and cable connectors. Some ramp wave loading experiments were conducted to check and examine the performances of CQ-3-MMAF. Two copper flyer plates were accelerated to about 3.5 km/s in one shot when the working voltage was charged to 70 kV. The velocity histories agree very well. The dynamic experiments of some polymer bonded explosives and phase transition of tin under ramp wave loadings were also conducted. The experimental data show that CQ-3-MMAF can be used to do material dynamics experiments in high rate and low cost shots. Based on this design concept, the peak
Yang, Chih-Cheng; Sheu, Shiann-Tsong
2013-01-01
This study investigates how to adjust the transmit power of femto base station (FBS) to mitigate interference problems between the FBSs and mobile users (MUs) in the 2-tier heterogeneous femtocell networks. A common baseline of deploying the FBS to increase the indoor access bandwidth requires that the FBS operation will not affect outdoor MUs operation with their quality-of-service (QoS) requirements. To tackle this technical problem, an FBS transmit power adjustment (FTPA) algorithm is proposed to adjust the FBS transmit power (FTP) to avoid unwanted cochannel interference (CCI) with the neighboring MUs in downlink transmission. FTPA reduces the FTP to serve its femto users (FUs) according to the QoS requirements of the nearest neighboring MUs to the FBS so that the MU QoS requirement is guaranteed. Simulation results demonstrate that FTPA can achieve a low MU outage probability as well as serve FUs without violating the MU QoS requirements. Simulation results also reveal that FTPA has better performance on voice and video services which are the major trend of future multimedia communication in the NGN. PMID:24391461
Po'ad, F. A.; Ismail, W.; Jusoh, J. F.
2017-08-01
This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.
Lemmink, K.A.P.M.; Verheijen, R.; Visscher, C.
2004-01-01
AIM: The purpose of this study was to examine the discriminative power of the recently developed Interval Shuttle Run Test (ISRT) and the widely used Maximal Multistage 20 m Shuttle Run Test (MMSRT) for soccer players at different levels of competition. The main difference between the tests is that
Gutman, Boris A; Hua, Xue; Rajagopalan, Priya; Chou, Yi-Yu; Wang, Yalin; Yanovsky, Igor; Toga, Arthur W; Jack, Clifford R; Weiner, Michael W; Thompson, Paul M
2013-04-15
We propose a new method to maximize biomarker efficiency for detecting anatomical change over time in serial MRI. Drug trials using neuroimaging become prohibitively costly if vast numbers of subjects must be assessed, so it is vital to develop efficient measures of brain change. A popular measure of efficiency is the minimal sample size (n80) needed to detect 25% change in a biomarker, with 95% confidence and 80% power. For multivariate measures of brain change, we can directly optimize n80 based on a Linear Discriminant Analysis (LDA). Here we use a supervised learning framework to optimize n80, offering two alternative solutions. With a new medial surface modeling method, we track 3D dynamic changes in the lateral ventricles in 2065 ADNI scans. We apply our LDA-based weighting to the results. Our best average n80-in two-fold nested cross-validation-is 104 MCI subjects (95% CI: [94,139]) for a 1-year drug trial, and 75AD subjects [64,102]. This compares favorably with other MRI analysis methods. The standard "statistical ROI" approach applied to the same ventricular surfaces requires 165 MCI or 94AD subjects. At 2 years, the best LDA measure needs only 67 MCI and 52AD subjects, versus 119 MCI and 80AD subjects for the stat-ROI method. Our surface-based measures are unbiased: they give no artifactual additive atrophy over three time points. Our results suggest that statistical weighting may boost efficiency of drug trials that use brain maps.
Kalsen, Anders; Hostrup, Morten; Backer, Vibeke; Bangsbo, Jens
2016-06-01
The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism, and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, 13 males [V̇o2 max: 45.0 ± 0.2 (means ± SE) ml·min(-1)·kg(-1)] performed a 30-s cycle ergometer sprint after inhalation of either 54 μg of formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC), and contractile properties of quadriceps were measured. Oxygen uptake was measured during the sprint. During the sprint, peak power, mean power, and end power were 4.6 ± 0.8, 3.9 ± 1.1, and 9.5 ± 3.2% higher (P power output during maximal sprinting is associated with increased rates of glycogenolysis and glycolysis that may counteract development of fatigue. Copyright © 2016 the American Physiological Society.
Caserotti, Paolo; Aagaard, Per; Simonsen, Erik Bruun
2001-01-01
Aging, muscle power, stretch-shortening cycle, eccentric muscle actions, concentric contractions......Aging, muscle power, stretch-shortening cycle, eccentric muscle actions, concentric contractions...
Brendle, Joerg
2016-01-01
We show that, consistently, there can be maximal subtrees of P (omega) and P (omega) / fin of arbitrary regular uncountable size below the size of the continuum. We also show that there are no maximal subtrees of P (omega) / fin with countable levels. Our results answer several questions of Campero, Cancino, Hrusak, and Miranda.
Østerås, Sindre; Welde, Boye; Danielsen, Jørgen; van den Tillaar, Roland; Ettema, Gertjan; Sandbakk, Øyvind
2016-09-01
Østerås, S, Welde, B, Danielsen, J, van den Tillaar, R, Ettema, G, and Sandbakk, Ø. Contribution of upper-body strength, body composition, and maximal oxygen uptake to predict double poling power and overall performance in female cross-country skiers. J Strength Cond Res 30(9): 2557-2564, 2016-Maximal oxygen uptake (V[Combining Dot Above]O2max) is regarded as the most performance-differentiating physiological measure in cross-country (XC) skiing. In addition, upper-body strength and lean mass have been associated with double poling (DP) power in XC skiers. In this study, we tested upper-body maximal strength, lean mass, and V[Combining Dot Above]O2max's contributions to predict DP power production of different durations and the overall XC skiing performance level of elite female XC skiers. Thirteen skiers (V[Combining Dot Above]O2max: 64.9 ± 4.2 ml·kg·min) performed one 30-second and one 3-minute DP performance test using a ski ergometer. The International Ski Federation's (FIS) ranking points determined their overall XC skiing performance. The skiers performed three 1-repetition maximal strength tests in poling-specific exercises that isolated the elbow extension, shoulder extension, and trunk flexion movements. Body composition was determined by a DXA scan, and V[Combining Dot Above]O2max was tested in an incremental running test. Multiple regressions were used to predict power production in the 30-second and 3-minute tests and FIS points. The 2 best predictions of 30-second DP power were lean upper-body mass and maximal upper-body strength (with the 3 strength tests normalized and pooled together as one variable) (R = 0.84 and 0.81, p skiing performance (R = 0.43 and 0.40, p ≤ 0.05). Although the importance of upper-body strength and lean mass to predict DP power production and the overall XC skiing performance declines with the performance duration in female XC skiers, the importance of V[Combining Dot Above]O2max shows an opposite relationship.
Strauss, HJ
2009-06-01
Full Text Available In this paper, researchers have demonstrated that a Ho:YLF oscillator and amplifier system can be designed in a compact setup where the pump power from an unpolarized fibre laser utilized efficiently. The system produced more than 20 mJ energy per...
Gebraad, Pieter [National Renewable Energy Laboratory, Golden CO USA; Thomas, Jared J. [Brigham Young University, Provo UT USA; Ning, Andrew [Brigham Young University, Provo UT USA; Fleming, Paul [National Renewable Energy Laboratory, Golden CO USA; Dykes, Katherine [National Renewable Energy Laboratory, Golden CO USA
2016-05-24
This paper presents a wind plant modeling and optimization tool that enables the maximization of wind plant annual energy production (AEP) using yaw-based wake steering control and layout changes. The tool is an extension of a wake engineering model describing the steady-state effects of yaw on wake velocity profiles and power productions of wind turbines in a wind plant. To make predictions of a wind plant's AEP, necessary extensions of the original wake model include coupling it with a detailed rotor model and a control policy for turbine blade pitch and rotor speed. This enables the prediction of power production with wake effects throughout a range of wind speeds. We use the tool to perform an example optimization study on a wind plant based on the Princess Amalia Wind Park. In this case study, combined optimization of layout and wake steering control increases AEP by 5%. The power gains from wake steering control are highest for region 1.5 inflow wind speeds, and they continue to be present to some extent for the above-rated inflow wind speeds. The results show that layout optimization and wake steering are complementary because significant AEP improvements can be achieved with wake steering in a wind plant layout that is already optimized to reduce wake losses.
Hostrup, Morten; Kalsen, Anders; Onslev, Johan; Jessen, Søren; Haase, Christoffer; Habib, Sajad; Ørtenblad, Niels; Backer, Vibeke; Bangsbo, Jens
2015-09-01
The study was a randomized placebo-controlled trial investigating mechanisms by which chronic β2-adrenergic stimulation enhances muscle force and power output during maximal cycle ergometer exercise in young men. Eighteen trained men were assigned to an experimental group [oral terbutaline 5 mg/30 kg body weight (bw) twice daily (TER); n = 9] or a control group [placebo (PLA); n = 9] for a 4-wk intervention. No changes were observed with the intervention in PLA. Isometric muscle force of the quadriceps increased (P ≤ 0.01) by 97 ± 29 N (means ± SE) with the intervention in TER compared with PLA. Peak and mean power output during 30 s of maximal cycling increased (P ≤ 0.01) by 32 ± 8 and 25 ± 9 W, respectively, with the intervention in TER compared with PLA. Maximal oxygen consumption (V̇o2max) and time to fatigue during incremental cycling did not change with the intervention. Lean body mass increased by 1.95 ± 0.8 kg (P ≤ 0.05) with the intervention in TER compared with PLA. Change in single fiber cross-sectional area of myosin heavy chain (MHC) I (1,205 ± 558 μm(2); P ≤ 0.01) and MHC II fibers (1,277 ± 595 μm(2); P ≤ 0.05) of the vastus lateralis muscle was higher for TER than PLA with the intervention, whereas no changes were observed in MHC isoform distribution. Expression of muscle proteins involved in growth, ion handling, lactate production, and clearance increased (P ≤ 0.05) with the intervention in TER compared with PLA, with no change in oxidative enzymes. Our observations suggest that muscle hypertrophy is the primary mechanism underlying enhancements in muscle force and peak power during maximal cycling induced by chronic β2-adrenergic stimulation in humans.
Rectify output of PWM power amplifier transmitted through long cable%PWM型功率放大器长线传输波形整型
王刚; 柳秋兴; 宋晓明; 柳井莉
2013-01-01
为解决PWM功率放大器输出长线传输引发的波形畸变,可能伤及力矩电动机的问题,对实际系统结构进行了理论分析,找出了可能引发波形畸变的原因,并给出了3种解决方法.实际试验结果证实所给方法的有效性.%When transmitted through long cable, the output of PWM power amplifier may be distorted. The distorted wave may damage torque motor. By analyzing system at work, the factors caused distortion are found, and three solutions are presented. Experiment result shows that these solutions are valid.
A MIMO Skywave Radar Scheme with High Transmitting Power Efficiency%一种高能量发射效率MIMO天波雷达方案
赵志国; 陈建文; 鲍拯
2012-01-01
为提高阵元空间多输入多输出(Multiple-Input Multiple-Output,MIMO)天波超视距雷达(Over-The-Horizon Radar,OTHR)发射天线辐射能量效率,提出了降维分时波束空间MIMO-OTHR方案,并在该方案下实现了发射自适应波束形成.该方案降低了不可见波束区发射能量,无方向图起伏过大问题,发射自由度降低较少,适合在多径杂波个数较多的背景下应用,且只需要简单的波束控制,易于工程实现.理论分析和仿真实验验证了该方案的有效性.%To enhance transmitting power efficiency in element-space multiple-input multiple-output (MIMO) skywave over-the-horizon radars (OTHR),a reduced dimension time diverse beamspace MMO-OTHR scheme is proposed, and transmitting adaptive digital beamforming is realized under the scheme. With the new scheme, the stared power in invisible beamspace is decreased without acute fluctuations in beam pattern, and little reduction of degree of freedom makes MMO-OTHR be able to work under the situation that the number of multipath clutters is large. The new scheme needs only beam direction control,which simplifies the MIMO realization in OTHR.Theoretical analyses and simulation results both show that the presented scheme is effective.
Optimized Power Dispatch Strategy for Offshore Wind Farms
Hou, Peng; Hu, Weihao; Zhang, Baohua
2016-01-01
Maximizing the power production of offshore wind farms using proper control strategy has become an important issue for wind farm operators. However, the power transmitted to the onshore substation (OS) is not only related to the power production of each wind turbine (WT) but also the power losses...
K B Athreya
2009-09-01
It is shown that (i) every probability density is the unique maximizer of relative entropy in an appropriate class and (ii) in the class of all pdf that satisfy $\\int fh_id_=_i$ for $i=1,2,\\ldots,\\ldots k$ the maximizer of entropy is an $f_0$ that is proportional to $\\exp(\\sum c_i h_i)$ for some choice of $c_i$. An extension of this to a continuum of constraints and many examples are presented.
Kochanowicz Andrzej
2016-12-01
Full Text Available The aim of the study was to define the relationship between maximal power of lower limbs, the biomechanics of the forward handspring vault and the score received during a gymnastics competition. The research involved 42 gymnasts aged 9-11 years competing in the Poland’s Junior Championships. The study consisted of three stages: first -estimating the level of indicators of maximal power of lower limbs tested on a force plate during the countermovement jump; second - estimating the level of biomechanical indicators of the front handspring vault. For both mentioned groups of indicators and the score received by gymnasts during the vault, linear correlation analyses were made. The last stage consisted of conducting multiple regression analysis in order to predict the performance level of the front handspring vault. Results showed a positive correlation (0.401, p < 0.05 of lower limbs’ maximal power (1400 ± 502 W with the judges’ score for the front handstand vault (13.38 ± 1.02 points. However, the highest significant (p < 0.001 correlation with the judges’ score was revealed in the angle of the hip joint in the second phase of the flight (196.00 ± 16.64° and the contact time of hands with the vault surface (0.264 ± 0.118 s, where correlation coefficients were: -0.671 and -0.634, respectively. In conclusion, the angles of the hip joint in the second phase of the flight and when the hands touched the vault surface proved to be the most important indicators for the received score.
Sossan, Fabrizio; Kosek, Anna Magdalena; Martinenas, Sergejus
2013-01-01
to predict the future temperature of the water and it manages its state (on and off) according to the forecasted PV production, which are computed starting from forecast of the solar irradiance. Simulations for the proof of concept and for validating the proposed control strategy are proposed. Results......This paper presents a model predictive control (MPC) strategy for maximizing photo-voltaic (PV) selfconsumption in a household context exploiting the flexible demand of an electric water heater. The predictive controller uses a water heater model and forecast of the hot Water consumption in order...... of the control approach are compared with a traditional thermostatic controller using historical measurements of a 10 kW PV installation. Economic results based on the Italian self consumption tariffs are also reported. The model of the water heater complex is a mixed grey and white box and its parameters have...
Maximizing the spectral and energy efficiency of ARQ with a fixed outage probability
Hadjtaieb, Amir
2015-10-05
This paper studies the spectral and energy efficiency of automatic repeat request (ARQ) in Nakagami-m block-fading channels. The source encodes each packet into L similar sequences and transmits them to the destination in the L subsequent time slots. The destination combines the L sequences using maximal ratio combining and tries to decode the information. In case of decoding failure, the destination feeds back a negative acknowledgment and then the source sends the same L sequences to the destination. This process continues until successful decoding occurs at the destination with no limit on the number of retransmissions. We consider two optimization problems. In the first problem, we maximize the spectral efficiency of the system with respect to the rate for a fixed power. In the second problem, we maximize the energy efficiency with respect to the transmitted power for a fixed rate. © 2015 IEEE.
Hostrup, Morten; Kalsen, Anders; Onslev, Johan
2015-01-01
of muscle proteins involved in growth, ion handling, lactate production and clearance increased (P≤0.05) with the intervention in TER compared to PLA, with no change in oxidative enzymes. Our observations suggest that muscle hypertrophy is the primary mechanism underlying enhancements in muscle force......The study was a randomized placebo-controlled trial investigating mechanisms by which chronic β2-adrenergic stimulation enhances muscle force and power output during maximal cycle ergometer exercise in young men. Eighteen trained men were assigned to an experimental group (oral terbutaline 5 mg∙30...... kgbw(-1) twice daily; TER, n=9) or a control group (placebo; PLA, n=9) for a four-week intervention. No changes were observed with the intervention in PLA. Isometric muscle force of the quadriceps increased (P≤0.01) by 97±29 N (mean±SE) with the intervention in TER compared to PLA. Peak and mean power...
Higgins, M F; Tallis, J; Price, M J; James, R S
2013-05-01
This study examined the effects of elevated buffer capacity [~32 mM HCO₃(-)] through administration of sodium bicarbonate (NaHCO₃) on maximally stimulated isolated mouse soleus (SOL) and extensor digitorum longus (EDL) muscles undergoing cyclical length changes at 37 °C. The elevated buffering capacity was of an equivalent level to that achieved in humans with acute oral supplementation. We evaluated the acute effects of elevated [HCO₃(-)] on (1) maximal acute power output (PO) and (2) time to fatigue to 60 % of maximum control PO (TLIM60), the level of decline in muscle PO observed in humans undertaking similar exercise, using the work loop technique. Acute PO was on average 7.0 ± 4.8 % greater for NaHCO₃-treated EDL muscles (P muscles (P muscle performance was variable, suggesting that there might be inter-individual differences in response to NaHCO₃ supplementation. These results present the best indication to date that NaHCO₃ has direct peripheral effects on mammalian skeletal muscle resulting in increased acute power output.
Saxena, Samveg
Homogeneous Charge Compression Ignition (HCCI) engines are one of the most promising engine technologies for the future of energy conversion from clean, efficient combustion. HCCI engines allow high efficiency and lower CO2 emission through the use of high compression ratios and the removal of intake throttle valves (like Diesel), and allow very low levels of urban pollutants like nitric oxide and soot (like Otto). These engines, however, are not without their challenges, such as low power density compared with other engine technologies, and a difficulty in controlling combustion timing. This dissertation first addresses the power output limits. The particular strategies for enabling high power output investigated in this dissertation focus on avoiding five critical limits that either damage an engine, drastically reduce efficiency, or drastically increase emissions: (1) ringing limits, (2) peak in-cylinder pressure limits, (3) misfire limits, (4) low intake temperature limits, and (5) excessive emissions limits. The research shows that the key factors that enable high power output, sufficient for passenger vehicles, while simultaneously avoiding the five limits defined above are the use of: (1) high intake air pressures allowing improved power output, (2) highly delayed combustion timing to avoid ringing limits, and (3) using the highest possible equivalence ratio before encountering ringing limits. These results are revealed by conducting extensive experiments spanning a wide range of operating conditions on a multi-cylinder HCCI engine. Second, this dissertation discusses strategies for effectively sensing combustion characteristics on a HCCI engine. For effective feedback control of HCCI combustion timing, a sensor is required to quantify when combustion occurs. Many laboratory engines use in-cylinder pressure sensors but these sensors are currently prohibitively expensive for wide-scale commercialization. Instead, ion sensors made from inexpensive sparkplugs
WANG Yu-xin
2013-09-01
Full Text Available In this paper, the traditional grid-connected PV perturbation method of disturbance near the maximum power point about the problems of shock，introduced a method based on single variable current control thought，established grid-connected PV maximum power tracking control system mathematical model, a novel single-variable current perturbation tracking method was put out, as long as the detected output current of the solar panel power generation system can achieve a stable variable maximum power tracking, through simulation and experimental study to verify the correctness of the model and the effectiveness of control methods.
Sedliak, M; Finni, T; Cheng, S; Haikarainen, T; Häkkinen, K
2008-03-01
This study aimed to compare day-to-day repeatability of diurnal variation in strength and power. Thirty-two men were measured at four time points (07 : 00 - 08 : 00, 12 : 00 - 13 : 00, 17 : 00 - 18 : 00, and 20 : 30 - 21 : 30 h) throughout two consecutive days (day 1 and day 2). Power during loaded squat jumps, torque and EMG during maximal (MVC) and submaximal (MVC40) voluntary isometric knee extension contractions were measured. The EMG/torque ratio during MVC and MVC40 was calculated to evaluate neuromuscular efficiency. A significant time-of-day effect with repeatable diurnal patterns was found in power. In MVC, a significant time-of-day effect was present on day 2, whereas day 1 showed a typical but nonsignificant diurnal pattern. EMG and antagonist co-activation during MVC remained statistically unaltered, whereas neuromuscular efficiency improved from day 1 to day 2. A similar trend was observed in MVC40 neuromuscular efficiency with significant time-of-day and day-to-day effects. Unaltered agonist and antagonist activity during MVC suggests that modification at the muscular level was the primary source for the diurnal variation in peak torque. A learning effect seemed to affect data in MVC40. In conclusion, the second consecutive test day showed typical diurnal variation in both maximum strength and power with no day-to-day effect of cumulative fatigue.
Kraemer, William J; Boyd, Brittny M; Hooper, David R; Fragala, Maren S; Hatfield, Disa L; Dunn-Lewis, Courtenay; Comstock, Brett A; Szivak, Tunde K; Flanagan, Shawn D; Looney, David P; Newton, Robert U; Vingren, Jakob L; Häkkinen, Keijo; White, Mark T; Volek, Jeff S; Maresh, Carl M
2014-09-01
The optimal time of day for training has become an important question for many strength and conditioning specialists, and this study was designed to add some insights into this complex question. The primary purpose of this investigation was to examine physical performance within the temporal context of the relationship between physical performance, epinephrine, and melatonin concentrations in the early morning (0530 hours) and late (1500 hours) afternoon in elite collegiate male track and field athletes (jumpers and sprinters). Subjects had a mean (±SD) age, height, and body mass of 20.4 (±1.6) years, 185.8 (±9.4) cm, and 77.9 (±8.5) kg, respectively. Blood was obtained before each AM and PM testing session. Mean plasma melatonin concentrations were 34.9 ± 22.7 pg·ml and 4.8 ± 3.3 pg·ml for the AM vs. PM trials, respectively, demonstrating a significant (p ≤ 0.05) difference between time points. Mean resting plasma epinephrine concentrations for AM (171.7 ± 33.7 pmol·L) and PM (127.6 ± 47.8 pmol·L) also differed significantly between trails at the different times. In addition, significant differences were observed with respect to foot quickness in the AM (5.14 ± 1.06 seconds) and PM (4.39 ± 0.76 seconds). Mean peak power output for vertical jump power was 5,407.1 ± 1,272.9 W, 5,384.6 ± 888.3 W for AM vs. PM trials, respectively, which were not significantly different. The results of this investigation indicate that time of day did not negatively impact whole body physical performance in trained track athletes but did impact the quality of quickness. Thus in the morning, whole body power performances may be enhanced through adrenergic arousal when melatonin is elevated. However, this was not the case for movements requiring quickness and accuracy of movement. To compensate for the "sleepiness" associated with high concentrations of melatonin, being secreted from the pineal gland representing a continued "sleepiness" effect on the body, early
Balsalobre-Fernández, Carlos; Tejero-González, Carlos M; Del Campo-Vecino, Juan; Alonso-Curiel, Dionisio
2013-03-01
The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photo-cells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=-2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=-1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=-1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=-1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers.
A Novel Bandwidth Efficient Transmit Diversity Scheme Based on Water-filling
SHENCong; DAILin; ZHOUShidong; YAOYan
2004-01-01
In this paper we propose a novel bandwidth efficient transmit diversity scheme based on layered space-time architecture, in which Channel state information (CSI) is fully utilized to maximize channel capacity according to water-filling principle. It is shown that compared with V-BLAST, this new scheme can maintain the same high bandwidth efficiency, but achieve much better performance thanks to more effective transmission power allocation and diversity gain.
Social group utility maximization
Gong, Xiaowen; Yang, Lei; Zhang, Junshan
2014-01-01
This SpringerBrief explains how to leverage mobile users' social relationships to improve the interactions of mobile devices in mobile networks. It develops a social group utility maximization (SGUM) framework that captures diverse social ties of mobile users and diverse physical coupling of mobile devices. Key topics include random access control, power control, spectrum access, and location privacy.This brief also investigates SGUM-based power control game and random access control game, for which it establishes the socially-aware Nash equilibrium (SNE). It then examines the critical SGUM-b
Switch and examine transmit diversity for spectrum sharing systems
Abdallah, Mohamed M.
2011-06-01
In this paper, we develop a switch and examine transmit diversity algorithm for spectrum sharing cognitive networks. We consider a cognitive network composed of a primary link that employs constant rate and constant power transmission scheme with automatic-and-repeat request (ARQ) protocol, while the secondary link is composed of a fixed power multiple-antenna secondary transmitter and a single antenna receiver. Our objective is to develop a low complex transmit diversity algorithm at the secondary transmitter that maximizes the performance of the secondary link in terms of the effective throughput while maintaining a predetermined maximum loss in the packet rate of the primary link. In achieving this objective, we develop an algorithm that selects the best antenna, which maintains the quality of the secondary link in terms of signal-to-noise ratio above a specific threshold, based on overhearing the acknowledgment (ACK) and negative acknowledgment (NACK) feedback messages transmitted over the primary link. We also develop closed form expressions for the bit error rates and the effective throughput of the secondary link. © 2011 IEEE.
Cherif, M; Chtourou, H; Souissi, N; Aouidet, A; Chamari, K
2016-12-01
This study was designed to assess the effect of strength and power training on throwing velocity and muscle strength in handball players according to their playing positions. Twenty-two male handball players were assigned to either an experimental group (n=11) or a control group (n=11) (age: 22.1 ± 3.0 years). They were asked to complete (i) the ball throwing velocity test and (ii) the one-repetition maximum (1-RM) tests for the half-back squat, the pull-over, the bench press, the developed neck, and the print exercises before and after 12 weeks of maximal power training. The training was designed to improve strength and power with an intensity of 85-95% of the 1RM. In addition to their usual routine handball training sessions, participants performed two sessions per week. During each session, they performed 3-5 sets of 3-8 repetitions with 3 min of rest in between. Then, they performed specific shots (i.e., 12 to 40). Ball-throwing velocity (p<0.001) was higher after the training period in rear line players (RL). The training programme resulted in an improvement of 1RM bench press (p<0.001), 1RM developed neck (p<0.001) and 1RM print (p<0.001) in both front line (FL) and RL. The control group showed a significant improvement only in ball-throwing velocity (p<0.01) and 1RM bench press (p<0.01) in RL. A significantly greater improvement was found in ball-throwing velocity (p<0.001), 1RM bench press (p<0.001), and 1RM half-back squat exercises in players of the central axis (CA) compared to the lateral axis (LA) (p<0.01). The power training programme induced significantly greater increases in ball-throwing velocity and muscle strength in FL than RL and in CA than LA axis players.
Kawahito, T. (Takamatsu National College of Technology, Kagawa (Japan)); Suzuki, T. (Tokushima University, Tokushima (Japan))
1994-03-20
This paper reports a method in a wind power generation system to control output current from a generator so that it fits automatically the wind turbine characteristics where the turbine characteristics are unknown and the generator characteristics are known. The paper details the following methods: a method that rotation speed of a wind turbine is observed to make the output current from the generator proportional to a square of the turbine rotation speed, and optimize the proportion coefficient so that the generator output at an equilibrium operation point of this system (wind turbine generated torque is in equilibrium with the generator driven torque) is maximized; and a method to derive an optimal proportion coefficient in discrete time control using a digital computer. The paper then describes the following matters: a simulation that assumes a pseudo natural wind velocity has verified the effectiveness of this control method; discovering an optimal proportion coefficient has required about ten minutes; and the way this control method handles fluctuation in wind velocity has a room of further improvement. 16 refs., 10 figs., 1 tab.
Gonzalo-Skok, Oliver; Tous-Fajardo, Julio; Arjol-Serrano, José Luis; Suarez-Arrones, Luis; Casajús, José Antonio; Mendez-Villanueva, Alberto
2016-05-01
To examine the effects of a low-volume repeated-power-ability (RPA) training program on repeated-sprint and change-of- direction (COD) ability and functional jumping performance. Twenty-two male elite young basketball players (age 16.2 ± 1.2 y, height 190.0 ± 10.0 cm, body mass 82.9 ± 10.1 kg) were randomly assigned either to an RPA-training group (n = 11) or a control group (n = 11). RPA training consisted of leg-press exercise, twice a week for 6 wk, of 1 or 2 blocks of 5 sets × 5 repetitions with 20 s of passive recovery between sets and 3 min between blocks with the load that maximized power output. Before and after training, performance was assessed by a repeated-sprint-ability (RSA) test, a repeated-COD-ability test, a hop for distance, and a drop jump followed by tests of a double unilateral hop with the right and left legs. Within-group and between-groups differences showed substantial improvements in slowest (RSAs) and mean time (RSAm) on RSA; best, slowest and mean time on repeated-COD ability; and unilateral right and left hop in the RPA group in comparison with control. While best time on RSA showed no improvement in any group, there was a large relationship (r = .68, 90% CI .43;.84) between the relative decrement in RSAm and RSAs, suggesting better sprint maintenance with RPA training. The relative improvements in best and mean repeated-COD ability were very largely correlated (r = .89, 90% CI .77;.94). Six weeks of lowvolume (4-14 min/wk) RPA training improved several physical-fitness tests in basketball players.
Wireless Networks with Energy Harvesting and Power Transfer: Joint Power and Time Allocation
Hadzi-Velkov, Zoran; Nikoloska, Ivana; Karagiannidis, George K.; Duong, Trung Q.
2016-01-01
In this paper, we consider wireless powered communication networks which could operate perpetually, as the base station (BS) broadcasts energy to the multiple energy harvesting (EH) information transmitters. These employ "harvest then transmit" mechanism, as they spend all of their energy harvested during the previous BS energy broadcast to transmit the information towards the BS. Assuming time division multiple access (TDMA), we propose a novel transmission scheme for jointly optimal allocation of the BS broadcasting power and time sharing among the wireless nodes, which maximizes the overall network throughput, under the constraint of average transmit power and maximum transmit power at the BS. The proposed scheme significantly outperforms "state of the art" schemes that employ only the optimal time allocation. If a single EH transmitter is considered, we generalize the optimal solutions for the case of fixed circuit power consumption, which refers to a much more practical scenario.
Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.
2012-01-01
Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel
Paul, P.; Bhattacharyya, D.; Turton, R.; Zitney, S.
2012-01-01
Future integrated gasification combined cycle (IGCC) power plants with CO{sub 2} capture will face stricter operational and environmental constraints. Accurate values of relevant states/outputs/disturbances are needed to satisfy these constraints and to maximize the operational efficiency. Unfortunately, a number of these process variables cannot be measured while a number of them can be measured, but have low precision, reliability, or signal-to-noise ratio. In this work, a sensor placement (SP) algorithm is developed for optimal selection of sensor location, number, and type that can maximize the plant efficiency and result in a desired precision of the relevant measured/unmeasured states. In this work, an SP algorithm is developed for an selective, dual-stage Selexol-based acid gas removal (AGR) unit for an IGCC plant with pre-combustion CO{sub 2} capture. A comprehensive nonlinear dynamic model of the AGR unit is developed in Aspen Plus Dynamics® (APD) and used to generate a linear state-space model that is used in the SP algorithm. The SP algorithm is developed with the assumption that an optimal Kalman filter will be implemented in the plant for state and disturbance estimation. The algorithm is developed assuming steady-state Kalman filtering and steady-state operation of the plant. The control system is considered to operate based on the estimated states and thereby, captures the effects of the SP algorithm on the overall plant efficiency. The optimization problem is solved by Genetic Algorithm (GA) considering both linear and nonlinear equality and inequality constraints. Due to the very large number of candidate sets available for sensor placement and because of the long time that it takes to solve the constrained optimization problem that includes more than 1000 states, solution of this problem is computationally expensive. For reducing the computation time, parallel computing is performed using the Distributed Computing Server (DCS®) and the Parallel
王麟; 聂广才; 王义林
2012-01-01
电力系统容量不足是广播电视发射台前进发展面临的难题之一.以安徽广播电视台大蜀山发射台的电力改造工程为例,探讨了发射台电力系统增容改造中所涉及的关键技术问题,并针对发射台必须减少停播率的要求,给出了一套最优的供电系统增容改造实施步骤.%Inadequate capacity of the power system is a problem in the development of broadcasting and television transmitting stations. In this paper, an example about power reconstruction project in Dashushan Transmitting Station of Anhui Broadcasting and Television Station is given. Many key technical issues about modification and uprating are discussed. In allusion to the special demand of reducing air rate of programs in transmitting station, a series of optimal implementation steps are given.
黄中瑞; 张剑云; 周青松
2015-01-01
In order to solve the problem that the power is transmitted dispersedly in traditional bistatic MIMO radar, a method about the transmit power focus of the bistatic MIMO radar is proposed. Firstly, the mathematic model is constructed based on an effective optimal criterion that can not only constrain the maximum error of the optimal beam and the desire one less than the given value, but also minimize the peak side lobe power of the transmit pattern. At the same time, a special beam matrix of transmitting terminal is constructed, not only making equivalent transmit/receive steering vector possessing the character of rotational invariance property, but also simplifying the original optimized model in order to be fast solved via second-order cone programming theory. Secondly, the transmitting and receiving angle of space target is estimated by utilizing improved PARallel FACtor (PARFAC) algorithm. The initial iteration point in the least square algorithm of PARFAC interior is improved by integrating into rotation invariance of transmitting/receiving steering vector, which can effectively decrease the number of iteration. Furthermore, the Cramer-Rao Bound of multi-target angle estimation under bistatic MIMO radar transmitting power focusing is derived which prove the superiority of the proposed method. Finally, the simulation results show the effectiveness of the theoretical analysis.%该文针对传统双基地MIMO雷达发射功率在空间发散的问题，提出一种双基地MIMO雷达发射功率聚焦方法。首先，建立了双基地MIMO雷达发射功率聚焦的优化模型，其优化准则为：在感兴趣空域内严格约束优化波束与期望波束的最大误差小于给定门限的前提下，最小化发射方向图的峰值旁瓣功率。同时，构造特殊发射端波束矩阵，不仅能使等效发射/接收导向矢量具有旋转不变性，并且简化了原优化模型，以便采用二阶锥规划理论进行快速求解；其次，利
Gutman, Boris A.; Hua, Xue; Rajagopalan, Priya; Chou, Yi-Yu; Wang, Yalin; Yanovsky, Igor; Toga, Arthur W.; Jack, Clifford R.; Weiner, Michael W.; Thompson, Paul M.
2013-01-01
We propose a new method to maximize biomarker efficiency for detecting anatomical change over time in serial MRI. Drug trials using neuroimaging become prohibitively costly if vast numbers of subjects must be assessed, so it is vital to develop efficient measures of brain change. A popular measure of efficiency is the minimal sample size (n80) needed to detect 25% change in a biomarker, with 95% confidence and 80% power. For multivariate measures of brain change, we can directly optimize n80 based on a Linear Discriminant Analysis (LDA). Here we use a supervised learning framework to optimize n80, offering two alternative solutions. With a new medial surface modeling method, we track 3D dynamic changes in the lateral ventricles in 2065 ADNI scans. We apply our LDA-based weighting to the results. Our best average n80—in two-fold nested cross-validation—is 104 MCI subjects (95% CI: [94,139]) for a 1-year drug trial, and 75 AD subjects [64,102]. This compares favorably with other MRI analysis methods. The standard “statistical ROI” approach applied to the same ventricular surfaces requires 165 MCI or 94 AD subjects. At 2 years, the best LDA measure needs only 67 MCI and 52 AD subjects, versus 119 MCI and 80 AD subjects for the stat-ROI method. Our surface-based measures are unbiased: they give no artifactual additive atrophy over three time points. Our results suggest that statistical weighting may boost efficiency of drug trials that use brain maps. PMID:23296188
Optimal Power Control in Wireless Powered Sensor Networks: A Dynamic Game-Based Approach
Xu, Haitao; Guo, Chao; Zhang, Long
2017-01-01
In wireless powered sensor networks (WPSN), it is essential to research uplink transmit power control in order to achieve throughput performance balancing and energy scheduling. Each sensor should have an optimal transmit power level for revenue maximization. In this paper, we discuss a dynamic game-based algorithm for optimal power control in WPSN. The main idea is to use the non-cooperative differential game to control the uplink transmit power of wireless sensors in WPSN, to extend their working hours and to meet QoS (Quality of Services) requirements. Subsequently, the Nash equilibrium solutions are obtained through Bellman dynamic programming. At the same time, an uplink power control algorithm is proposed in a distributed manner. Through numerical simulations, we demonstrate that our algorithm can obtain optimal power control and reach convergence for an infinite horizon. PMID:28282945
ADAPTIVE MODULATION AND POWER CONTROL FOR THROUGHPUT ENHANCEMENT IN COGNITIVE RADIOS
无
2008-01-01
To regulate the transmit-power and enhance the total throughput, a novel Transmit Power Control Game (TPCG) algorithm and an adaptive Modulation TPCG (M-TPCG) algorithm which combine bandwidth allocation, adaptive modulation and transmit-power control based on Space Time Block Coding (STBC) OFDM-CDMA system are designed and a cross-layer framework of database sharing is proposed. Simulation results show that the TPCG algorithm can regulate their transmitter powers and enhance the total throughput effectively, M-TPCG algorithm can achieve maximal system throughput. The performance of the cognitive radio system is improved obviously.
Roberto Deboli
2013-09-01
Full Text Available To correctly evaluate the vibration transmitted to the operators, it is necessary to consider each body’s point interested by the vibratory stimulus produced by machines. All the body’s part in contact to the vibration, when a portable device with internal combustion engine is used, are: hands, back and shoulders. Some information for wholebody vibration are available in the ISO 2631-1997 standard, which otherwise refers to a seated operator. ‘C’ type standards for the vibration analysis exist for some portable machines with an internal combustion engine which is comprehensive in the machine (chainsaw, brush-cutter, blower. If the engine is not inside the machine, but it is on the operator’s back, ‘C’ type standards on vibration measurements are quite incomplete. The IMAMOTER institute of CNR, the DISAFA Department (University of Turin and the Occupational Medicine Department of the University of Catania started some tests to verify the vibration levels transmitted to an operator working with backed engine devices. Two machines have been examined: a blower and a spraying machine. Two operative conditions have been considered during all the tests: idling and full load. Three operators have been involved and each test has been repeated three times. The spraying machine has been tested both with the empty tank and with 10 litres of water, to simulate the load to be caused by the presence of liquid inside the tank. In this work the comfort condition of ISO 2631-1 standard was considered, using the frequency weighting Wc curve with the weighting factor 0.8 for X axis (back-ventral direction and the Wd curve for Y and Z axis (shoulder - shoulder and buttocks - head with weighting factors 0.5 and 0.4 (respectively for Y and Z axis. Data were examined using IBM SPSS Statistics 20 software package. The statistical analysis underlined that the running condition is the main factor to condition the vibration levels transmitted to the operator
陈树勇; 陈会员; 唐晓骏; 宋云亭; 曾令全
2013-01-01
The putting into operation of energy base, where wind power is bundled with thermal-generated power, can bring great economic benefits, meanwhile it will also leads to the variation of both security and stability in the power grid located in the energy base. It is hard to ensure stable operation of the power grid by only tripping conventional thermal generation units after certain serious faults or the cost of tripping conventional thermal generation units is too high. In allusion to it, firstly, the difference between the transient characteristics of thermal generation units and that of wind power generation units as well as the impacts of the two kinds of transient characteristics on system transient stability are analyzed; secondly, it is pointed out that there are two main reasons causing post-fault system instability: one of them is the accelerating energy produced during fault process and the another one is the sharp decline of the capability of outward power transmission system due to the weakening of outward power transmission channel; thirdly, an optimal scheme for tripping thermal units and wind power units after the serious faults is proposed. Simulation results of a certain energy base in West China, where the thermal-generated power is bundled with wind power, show that under the premise of ensuring post-fault secure and stable operation of the power grid, using the proposed optimal generator tripping scheme the quantity of generators to be tripped can be evidently reduced and the restoration characteristics of post-fault power grid can be improved, thus both security and economy of the power grid can be obviously enhanced.%风火打捆能源基地的投入运行,在带来巨大经济效益的同时也引起电网安全稳定性发生变化.某些严重故障后,仅切除常规火电机组难以保证系统稳定运行或代价过大.首先分析了风电机组和火电机组暂态特性的差异性以及各自对系统暂态稳定的影响.然后指
Weighted-Sum-Rate-Maximizing Linear Transceiver Filters for the K-User MIMO Interference Channel
Shin, Joonwoo
2012-01-01
This letter is concerned with transmit and receive filter optimization for the K-user MIMO interference channel. Specifically, linear transmit and receive filter sets are designed which maximize the weighted sum rate while allowing each transmitter to utilize only the local channel state information. Our approach is based on extending the existing method of minimizing the weighted mean squared error (MSE) for the MIMO broadcast channel to the K-user interference channel at hand. For the case of the individual transmitter power constraint, however, a straightforward generalization of the existing method does not reveal a viable solution. It is in fact shown that there exists no closed-form solution for the transmit filter but simple one-dimensional parameter search yields the desired solution. Compared to the direct filter optimization using gradient-based search, our solution requires considerably less computational complexity and a smaller amount of feedback resources while achieving essentially the same lev...
Sexually transmitted diphtheria.
Berger, Anja; Lensing, Carmen; Konrad, Regina; Huber, Ingrid; Hogardt, Michael; Sing, Andreas
2013-03-01
Diphtheria is caused by diphtheria toxin-producing Corynebacterium species. While classical respiratory diphtheria is transmitted by droplets, cutaneous diphtheria often results from minor trauma. This report concerns the first case of sexually transmitted diphtheria in a patient with non-gonococcal urethritis after orogenital contact.
Profit maximization mitigates competition
Dierker, Egbert; Grodal, Birgit
1996-01-01
We consider oligopolistic markets in which the notion of shareholders' utility is well-defined and compare the Bertrand-Nash equilibria in case of utility maximization with those under the usual profit maximization hypothesis. Our main result states that profit maximization leads to less price...... competition than utility maximization. Since profit maximization tends to raise prices, it may be regarded as beneficial for the owners as a whole. Moreover, if profit maximization is a good proxy for utility maximization, then there is no need for a general equilibrium analysis that takes the distribution...... of profits among consumers fully into account and partial equilibrium analysis suffices...
Tallis, J; James, R S; Cox, V M; Duncan, M J
2017-01-01
Caffeine is a well-established performance enhancing nutritional supplement in a young healthy population, however far less is known about how its ergogenicity is affected by increasing age. A recent review has highlighted the value of studies examining the direct effect of caffeine on isolated skeletal muscle contractility, but the present work is the first to assess the direct effect of 70µM caffeine (physiological maximum) on the maximal power output of isolated mammalian muscle from an age range representing developmental to early ageing. Female CD1 mice were aged to 3, 10, 30 and 50 weeks (n = 20 in each case) and either whole EDL or a section of the diaphragm was isolated and maximal power output determined using the work loop technique. Once contractile performance was maximised, each muscle preparation was treated with 70µM caffeine and its contractile performance was measured for a further 60 minutes. In both mouse EDL and diaphragm 70µM caffeine treatment resulted in a significant increase in maximal muscle power output that was greatest at 10 or 30 weeks (up to 5% and 6% improvement respectively). This potentiation of maximal muscle power output was significantly lower at the early ageing time point, 50 weeks (up to 3% and 2% improvement respectively), and in mice in the developmental stage, at 3 weeks of age (up to 1% and 2% improvement respectively). Uniquely, the present findings indicate a reduced age specific sensitivity to the performance enhancing effect of caffeine in developmental and aged mice which is likely to be attributed to age related muscle growth and degradation, respectively. Importantly, the findings indicate that caffeine may still provide a substantial ergogenic aid in older populations which could prove important for improving functional capacity in tasks of daily living.
Kalsen, Anders; Hostrup, Morten; Backer, Vibeke
2016-01-01
L min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured...
Sexually transmitted infections
AJRH Managing Editor
treatment practices of sexually transmitted infections among brothel based female sex workers Three hundred and twenty three consenting ... five top diseases for which Nigerians seek medical ... in other countries have also revealed a high.
Sexually transmitted diseases (STDs) are infections that are passed from one person to another through sexual contact. The causes of STDs ... often help with the symptoms and keep the disease under control. Correct usage of latex condoms greatly ...
Sexually transmitted infections.
Fuchs, Wolfgang; Brockmeyer, Norbert H
2014-06-01
In no other medical field former rare infections of the 1980(th) and 1990(th) occur again as this is seen in the field of venerology which is as well based on the mobility of the population. Increasing rates of infections in Europe, and increasing bacteriological resistances face health professionals with new challenges. The WHO estimates more than 340 million cases of illnesses worldwide every year. Diseases caused by sexually transmitted infections (STI) in a strict sense are syphilis, gonorrhea, lymphogranuloma venereum, granuloma inguinale, and chancroid. In a wider sense, all illnesses are included which can mainly be transmitted through sexual contact. The term "sexual contact" has to be seen widely, from close physical contact to all variants of sexual behavior. This CME article is an overview of the most common occurring sexually transmitted infections in clinical practice. Both, basic knowledge as well as recent developments are discussed below.
Maximally incompatible quantum observables
Heinosaari, Teiko, E-mail: teiko.heinosaari@utu.fi [Turku Centre for Quantum Physics, Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Schultz, Jussi, E-mail: jussi.schultz@gmail.com [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Toigo, Alessandro, E-mail: alessandro.toigo@polimi.it [Dipartimento di Matematica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano (Italy); Istituto Nazionale di Fisica Nucleare, Sezione di Milano, Via Celoria 16, I-20133 Milano (Italy); Ziman, Mario, E-mail: ziman@savba.sk [RCQI, Institute of Physics, Slovak Academy of Sciences, Dúbravská cesta 9, 84511 Bratislava (Slovakia); Faculty of Informatics, Masaryk University, Botanická 68a, 60200 Brno (Czech Republic)
2014-05-01
The existence of maximally incompatible quantum observables in the sense of a minimal joint measurability region is investigated. Employing the universal quantum cloning device it is argued that only infinite dimensional quantum systems can accommodate maximal incompatibility. It is then shown that two of the most common pairs of complementary observables (position and momentum; number and phase) are maximally incompatible.
Natavan M. Gadzhiyeva
2017-07-01
Full Text Available The present study investigated the effects of a salesperson's use of language power and nonverbal immediacy on the persuasiveness of the salesperson. A high level of language power and a high level of nonverbal immediacy were hypothesized to singularly and jointly increase a salesperson's level of persuasiveness. A sample of 211 undergraduate students voluntarily completed an online survey, which displayed a video clip of a sales presentation. Each participant randomly viewed one of four video clips, which differed in terms of the salesperson's levels of language power (powerful vs. powerless and nonverbal immediacy (high vs. low. A three-way ANOVA indicated that language power had a significant main effect on persuasion in the expected direction, and also revealed a significant interaction between nonverbal immediacy and participant biological sex. However, there were no main effects for nonverbal immediacy and participant biological sex, and no interaction effect was found between language power and nonverbal immediacy. Subsequent data analysis revealed that the perceived power of the speaker mediated the relationship between language power and the extent of persuasion. We conclude the article with a discussion of the implications of our findings for both researchers and practitioners.
Outage Constrained Secrecy Rate Maximization Using Cooperative Jamming
Luo, Shuangyu; Petropulu, Athina
2012-01-01
We consider a Gaussian MISO wiretap channel, where a multi-antenna source communicates with a single-antenna destination in the presence of a single-antenna eavesdropper. The communication is assisted by multi-antenna helpers that act as jammers to the eavesdropper. Each helper independently transmits noise which lies in the null space of the channel to the destination, thus creates no interference to the destination. Under the assumption that there is eavesdropper channel uncertainty, we derive the optimal covariance matrix for the source signal so that the secrecy rate is maximized subject to probability of outage and power constraints. Assuming that the eavesdropper channels follow zero-mean Gaussian model with known covariances, we derive the outage probability in a closed form. Simulation results in support of the analysis are provided.
Varanasi, Jhansi L; Sinha, Pallavi; Das, Debabrata
2017-05-01
To selectively enrich an electrogenic mixed consortium capable of utilizing dark fermentative effluents as substrates in microbial fuel cells and to further enhance the power outputs by optimization of influential anodic operational parameters. A maximum power density of 1.4 W/m(3) was obtained by an enriched mixed electrogenic consortium in microbial fuel cells using acetate as substrate. This was further increased to 5.43 W/m(3) by optimization of influential anodic parameters. By utilizing dark fermentative effluents as substrates, the maximum power densities ranged from 5.2 to 6.2 W/m(3) with an average COD removal efficiency of 75% and a columbic efficiency of 10.6%. A simple strategy is provided for selective enrichment of electrogenic bacteria that can be used in microbial fuel cells for generating power from various dark fermentative effluents.
Study on Wireless Power Transmission for Gastrointestinal Microsystems Based on Inductive Coupling
无
2007-01-01
Wireless power transmission based on inductive coupling for remotely implanted micro devices has been considered in this paper. The receiving coil, integrated in microsystems and the external transmitting coil compose a loosely coupled transformer. The coupling coefficient was calculated and measured on spacing misalignments. The geometric size of transmitting coil was analyzed for the target of remotely delivering power. The received power was maximized by choosing appropriate value of frequency, tuning capacitance and the load resistance. A conventional full bridge rectifier circuit was employed to convert ac to dc voltage. The Received dc power was up to 160 mW with a transmitting voltage of 5 Vrms when the receiving coil was placed at the center of the transmitting coil.This may meet the requirement of some microsystems for high power over a long time.
Adaptive transmit selection with interference suppression
Radaydeh, Redha Mahmoud Mesleh
2010-01-01
This paper studies the performance of adaptive transmit channel selection in multipath fading channels. The adaptive selection algorithms are configured for single-antenna bandwidth-efficient or power-efficient transmission with as low transmit channel estimations as possible. Due to the fact that the number of active co-channel interfering signals and their corresponding powers experience random behavior, the adaptation to channels conditions, assuming uniform buffer and traffic loading, is proposed to be jointly based on the transmit channels instantaneous signal-to-noise ratios (SNRs) and signal-to- interference-plus- noise ratios (SINRs). Two interference cancelation algorithms, which are the dominant cancelation and the less complex arbitrary cancelation, are considered, for which the receive antenna array is assumed to have small angular spread. Analytical formulation for some performance measures in addition to several processing complexity and numerical comparisons between various adaptation schemes are presented. ©2010 IEEE.
Iizima, M. [Tokyo Electric Power Co., Inc. (Japan)] Saito, S. [Toden Design Co. Ltd., Tokyo (Japan)] Mishima, T. [Maeda Construction Co. Ltd., Tokyo (Japan)
1997-11-05
When a footing of a steel tower for transmitting electric power is affected by vertical loads of both compression and lifting due to a wind load, fixation of leg materials as installation portions of the steel tower and the footing is important from a point of ensuring reliability of power transmission under such large loads. In this paper, results of studies on a model experiment executed for a purpose of enlarging and application scope of the leg materials fixation to deep footings, and numerical analysis which is executed by a finite element method considering tensile softening caused by crack of concrete for carrying destruction mechanism are described. It is re-confirmed that crack-resistant force is not in proportion to the increase of a body diameter and it is newly clarified that the crack-resistant force is not in proportion to the increase of concrete hardness either. A the model experiment can be simulated by executing the numerical analysis considering the tensile softening of concrete caused by a crack, effects of the concrete hardness and the body size upon a fixing strength of leg materials are examined. 7 refs., 21 figs., 3 tabs.
Parker, Andrew M.; Wandi Bruine de Bruin; Baruch Fischhoff
2007-01-01
Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007). Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002), we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions...
一种平面结构无线供电发送线圈的设计%A Design of a Planner Transmitting Coil for Wireless Power Transfer
程筱军
2015-01-01
The impedance matching network can be used to optimize the efficiency of the wireless power transfer, if the coupling coefficient between the transmitting and the received coils are not variable .In order to achieving uniform magnetic filed which is produced by the transmitting coil , a new design method is proposed . A series of concentric circular turns are parallel connected with a capacitor connected in series with each turn . The current in each turn which is determined by the capacitor should be designed carefully .The new design is verified by the HFSS simulation .Compared with the traditional spiral coil which depends on the turn position distribution , the new design is better in achieving uniform magnetic field .%在手机等无线供电平台应用中，阻抗匹配网络提高效率的方法在发送线圈和接收线圈间的耦合系数变化时无法达到最优。为此，提出了一种在离发送线圈一定高度处产生均匀磁场的发送线圈设计方法，通过并联多个同心圆线圈，并在每圈上并联一个电容，使每圈上电流的比例由电容值比例决定。经仿真验证，相比于传统的依靠每圈之间线间距不同的串联型平面螺旋线圈，该方法得到磁场均匀性更好。
Manoj Kumar; Anant Deshpande; Chintan Gupta; A K Biswas; A K Nath
2002-12-01
Selective multi-photon dissociation (MPD) of Freon-22 (CF2HCl) molecules has been carried out using a TEA CO2 laser at various CO2 laser lines (9(20)-9(26)) in order to maximize the yield of C-13 isotope in the product (C2F4) at an enrichment factor of 100. The effects of laser pulse tail due to the presence of N2 in the laser mixture on the enrichment factor and yield of C-13 are investigated. It is found that the addition of a small amount of N2 is possible in the laser mixture without a significant drop in the yield at desired enrichment factor. Addition of a small amount of N2 improves the laser efficiency considerably. At a given pulse energy, a slight change in the near field intensity distribution of a laser severely affects the selectivity of C-13 isotope. The computed far-field intensity distributions of the measured near-field intensities show marked spatial variation in the focal spots that leads to a drop in selectivity. For macroscopic production of C-13 isotope a simple and novel multi-pass cavity has been designed and tested to focus the energy repeatedly keeping the optimum fluence constant at each focal spot.
柳国环; 练继建; 于通顺
2014-01-01
近海风力发电结构是由无限域地基、基础及上部结构组成的体系，有限域透射人工边界和地震动输入模式直接影响结构体系的动力响应。首先，建立透射人工边界-地基-基础-塔筒结构和固定边界-地基-基础-塔筒结构的有限元模型；然后，简要澄清了透射边界地震动输入之所以采用外力而不采取地震动物理量（加速度、速度和位移）的原因所在；最后，对给出的3种作用模式：（1）固定边界地震动输入，（2）只考虑外源输入波作用，（3）同时考虑外源输入波和内源振动的散射波作用，分别进行计算分析和比较。通过数值计算并结合理论分析，（1）澄清了对透射边界采用外力进行地震激励输入的方法的原因，这种输入方法合理可靠，符合实际情况；（2）在地震波等效荷载的生成中，针对圆形横截面地基提出了一种阻尼力、刚度力的便捷性生成方法，大大减小了工作量；（3）从自身振动特点及阻尼设置角度，解释了地震作用下采用透射边界比采用固定边界时风电结构响应减小的原因；（4）指出了地震作用下透射边界地基模型在结构动力响应与倒塌计算中内源振动反射的不容忽视性。%Offshore wind power structure is the system of superstructure-foundation-infinite domain soil. Dynamic response of structure system is directly affected by transmitting boundary of the model and seismic motion input mode. Firstly, finite element models of tower tubes-foundation-soil-transmitting boundary and tower tubes-foundation-soil-fixed boundary are established. Then, the reason why force instead of acceleration, velocity and displacement is used for seismic input in the model while transmitting boundary is briefly clarified. At last, the following modes are analyzed, i.e. (1) seismic input of fixed boundary;(2) external source wave motion is considered only; (3) external
Colak, R; Ozcelik, O
2004-01-01
We examined the effects of weight loss induced by diet-orlistat (DO) and diet-orlistat combined with exercise (DOE) on maximal work rate production (Wmax) capacity in obese patients. Total of 24 obese patients were involved in this study. Twelve of them were subjected to DO therapy only and the remaining 12 patients participated in a regular aerobic exercise-training program in addition to DO therapy (DOE). Each patient performed two incremental ramp exercise tests up to exhaustion using an electromagnetically-braked cycle ergometer: one at the onset and one at the end of the 4th week. DOE therapy caused a significant decrease in total body weight: 101.5+/-17.4 kg (basal) vs 96.3+/-17.3 kg (4 wk) associated with a significant decrease in body fat mass: 45.0+/-10.5 kg (basal) vs 40.9+/-9.8 kg (4 wk). DO therapy also resulted in a significant decrease of total body weight 94.9+/-14.9 kg (basal) vs 91.6+/-13.5 kg (4 wk) associated with small but significant decreases in body fat mass: 37.7+/-5.6 kg (basal) to 36.0+/-6.2 kg (4 wk). Weight reduction achieved during DO therapy was not associated with increased Wmax capacity: 106+/-32 W (basal) vs 106+/-33 W (4 wk), while DOE therapy resulted in a markedly increased Wmax capacity: 109+/-39 W (basal) vs 138+/-30 W (4 wk). DO therapy combined with aerobic exercise training resulted in a significant reduction of fat mass tissue and markedly improved the aerobic fitness and Wmax capacities of obese patients. Considering this improvement within such a short period, physicians should consider applying an aerobic exercise-training program to sedentary obese patients for improving their physical fitness and thereby reduce the negative outcomes of obesity.
Ming Yi WANG; Guo ZHAO
2005-01-01
A right R-module E over a ring R is said to be maximally injective in case for any maximal right ideal m of R, every R-homomorphism f : m → E can be extended to an R-homomorphism f' : R → E. In this paper, we first construct an example to show that maximal injectivity is a proper generalization of injectivity. Then we prove that any right R-module over a left perfect ring R is maximally injective if and only if it is injective. We also give a partial affirmative answer to Faith's conjecture by further investigating the property of maximally injective rings. Finally, we get an approximation to Faith's conjecture, which asserts that every injective right R-module over any left perfect right self-injective ring R is the injective hull of a projective submodule.
Andrew M. Parker
2007-12-01
Full Text Available Our previous research suggests that people reporting a stronger desire to maximize obtain worse life outcomes (Bruine de Bruin et al., 2007. Here, we examine whether this finding may be explained by the decision-making styles of self-reported maximizers. Expanding on Schwartz et al. (2002, we find that self-reported maximizers are more likely to show problematic decision-making styles, as evidenced by self-reports of less behavioral coping, greater dependence on others when making decisions, more avoidance of decision making, and greater tendency to experience regret. Contrary to predictions, self-reported maximizers were more likely to report spontaneous decision making. However, the relationship between self-reported maximizing and worse life outcomes is largely unaffected by controls for measures of other decision-making styles, decision-making competence, and demographic variables.
Brüstle, Thomas; Pérotin, Matthieu
2012-01-01
Maximal green sequences are particular sequences of quiver mutations which were introduced by Keller in the context of quantum dilogarithm identities and independently by Cecotti-Cordova-Vafa in the context of supersymmetric gauge theory. Our aim is to initiate a systematic study of these sequences from a combinatorial point of view. Interpreting maximal green sequences as paths in various natural posets arising in representation theory, we prove the finiteness of the number of maximal green sequences for cluster finite quivers, affine quivers and acyclic quivers with at most three vertices. We also give results concerning the possible numbers and lengths of these maximal green sequences. Finally we describe an algorithm for computing maximal green sequences for arbitrary valued quivers which we used to obtain numerous explicit examples that we present.
Hanon, Christine; Dorel, Sylvain; Delfour-Peyrethon, Rémi; Leprêtre, Pierre-Marie; Bishop, David J; Perrey, Stéphane; Thomas, Claire
2013-01-01
To investigate the physiological mechanisms that explain the end-exercise decrease in oxygen uptake [Formula: see text] during strenuous constant-power exercise, we recruited eleven trained, track cyclists. On two separated days they performed 1) resting spirometric measures, followed by an incremental test on a cycle ergometer to determine the power output at [Formula: see text] and 2) an exhaustive isokinetic supramaximal cycling exercise (Tlimsupra) at 185 ± 24% of [Formula: see text] (i.e., 640.5 ± 50.8 W). During cycling exercise tests, [Formula: see text], ventilation parameters, stroke volume (SV) and heart rate were continuously recorded. Furthermore, arterialised capillary blood samples were collected to measure blood pH, arterial oxygen saturation, lactate and bicarbonate concentration before and 5 min after Tlimsupra. A > 5% decrease in [Formula: see text] and/or SV was observed in 6 subjects, with 5 out of 6 subjects presenting both phenomena. The magnitude of the [Formula: see text] decrease was correlated with the magnitude of the SV decrease (R = 0.75, P decrease in forced vital capacity and forced inspiratory volume corroborate with a possible respiratory muscle fatigue. Based on these findings, we demonstrate that the occurrence of [Formula: see text] decrease in more than half of our subjects, during a strenuous constant-power exercise leading to a mild-acidosis (pH = 7.21 ± 0.04), results mainly from cardio-respiratory factors and not from blood metabolic responses.
Gritti, Fabrice; Gilar, Martin; Jarrell, Joseph A
2016-04-29
A cylindrical vacuum chamber (inner diameter 5 cm) housing a narrow-bore 2.1 mm×100 mm column packed with 1.8 μm HSS-T3 fully porous particles was built in order to isolate thermally the chromatographic column from the external air environment. Consistent with statistical physics and the mean free path of air molecules, the experimental results show that natural air convection and conduction are fully eliminated for housing air pressures smaller than 10(-4) Torr. Heat radiation is minimized by wrapping up the column with low-emissivity aluminum-tape (emissivity coefficient ϵ=0.03 vs. 0.28 for polished stainless steel 316). Overall, the heat flux at the column wall is reduced by 96% with respect to standard still-air ovens. From a practical viewpoint, the efficiency of the column run at a flow rate of 0.6 mL/min at a constant 13,000 psi pressure drop (the viscous heat power is around 9 W/m) is improved by up to 35% irrespective of the analyte retention. Models of heat and mass transfer reveal that (1) the amplitude of the radial temperature gradient is significantly reduced from 0.30 to 0.01 K and (2) the observed improvement in resolution power stems from a more uniform distribution of the flow velocity across the column diameter. The eddy dispersion term in the van Deemter equation is reduced by 0.8±0.1 reduced plate height unit, a significant gain in column performance. Copyright © 2016 Elsevier B.V. All rights reserved.
Minimum Transmit Power Based Distributed Relay Selection in Wireless Networks%无线网络功率最小化的分布式中继选择方法
武航; 钱丽萍; 陈庆章; 卢为党
2016-01-01
中继协作已视作提高边沿用户能量有效性和服务质量的新型技术.因此,针对存在瑞利衰落的解码转发中继网络如何选择中继节点以最小化系统总功率的问题,提出了使用分布式拍卖算法选择合适的中继节点以最小化系统总传输功率.该算法首先通过信道传输功率的闭合表达式得到用户节点和中继节点的最小传输功率,然后根据分布式拍卖算法为用户节点分配合适的中继节点.仿真结果显示用户节点仅需要通过和中继节点交换少量信息就可以选择合适的中继节点.%Relay cooperation has been proposed as a promising solution to improve the energy efficiency and service quality of edge users. In this regard,this work proposes a distributed auction-based relay selection algorithm to mini-mize the total transmit power consumption for dual-hop decode-and-forward relay networks over Rayleigh fading channels. In particular,we first provide the optimal power consumption of any cooperative transmission in the closed-form expression. Then,we design a distributed relay selection algorithm that assigns every user to the appro-priate relay node based on the idea of auction. Simulation results show that every user node can find its best coopera-tive relay through limited message passing with relay nodes.
[Sexually transmitted infections].
De Toni, T; Fontana, I
2002-12-01
Sexually transmitted diseases (STD) are quite common and observed more frequently in teens. The adolescents represent a group at particular risk for STD due to biological, sociocultural and psychological factors. Undectected infections may lead to unwanted sequelae, including pelvic inflammatory disease, chronic abdominal pain, tubal scarring and increased risk of ectopic pregnancy. This paper deals with infections by Candida albicans, Chlamidia tracomatis, Neisseria gonorrheae, Gardnerella vaginalis, Treponema pallidum, Tricomonas vaginalis, Herpes simplex, Papilloma virus. In regard to gonorrhea, chlamydia, syphilis and papilloma virus, the expectation is that improved detection will decrease sequelae by early diagnosis and treatment. Prevention programs (information, use of hormonal contraception associated with condom use) and improved access to STD diagnosis and treatment services are useful to reduce the incidence of STD among young people.
Normal transmitting boundary conditions
廖振鹏
1996-01-01
The multi-transmitting formula (MTF) governed by a single artificial speed is analytically developed into a generalized MTF governed by a few artificial speeds to improve its capacity in simultaneous simulation of several one-way waves propagating at different speeds.The generalized MTF is then discretized and further generalized using the space extrapolation to improve its accuracies in numerical simulation of transient waves at large angles of incidence.The above two successive generalizitions of MTF based on the notion of normal transmission lead to a compact formula of local non-reflecting boundary condition.The formula not only provides a general representation of the major schemes of existing local boundary conditions but can be used to generate new schemes,which combine advantages of different schemes.
Sexually transmitted proctitis
Sidney Roberto Nadal
2012-03-01
Full Text Available Proctitis caused by sexually transmitted agents is usually taken for inflammatory bowel diseases, because of similar complaints, such as pain, bleeding and mucopurulent discharge, as well as the histopathology. Thus, its treatment is postponed and, sometimes, complications appear. The most common etiologic agents are Neisseria gonorrhoeae, Chlamydia trachomatis, Treponema pallidum and Herpes simplex. In order to avoid dissemination and complications, laboratory tests are essential for diagnosis and proper therapy. The objective of this article was to raise awareness to sexually transmitted diseases in proctitis etiology, as well as their diagnosis and treatment.As retites provocadas por agentes sexualmente transmissíveis são frequentemente confundidas com doenças inflamatórias intestinais, uma vez que as queixas mais comuns, que incluem dor, sangramento e secreção mucopurulenta, e o padrão histopatológico são semelhantes. Dessa maneira, o tratamento é postergado e, algumas vezes, as complicações aparecem. Os agentes mais comuns incluem a Neisseria gonorrhoeae, a Chlamydia trachomatis, o Treponema pallidum e o Herpes simplex. Exames laboratoriais sensíveis e específicos para confirmação diagnóstica são essenciais para o tratamento correto, evitando a disseminação e as sequelas. O objetivo deste artigo foi chamar a atenção para as doenças sexualmente transmissíveis na etiologia das retites, bem como seu diagnóstico e tratamento.
Asymptotics of robust utility maximization
Knispel, Thomas
2012-01-01
For a stochastic factor model we maximize the long-term growth rate of robust expected power utility with parameter $\\lambda\\in(0,1)$. Using duality methods the problem is reformulated as an infinite time horizon, risk-sensitive control problem. Our results characterize the optimal growth rate, an optimal long-term trading strategy and an asymptotic worst-case model in terms of an ergodic Bellman equation. With these results we propose a duality approach to a "robust large deviations" criterion for optimal long-term investment.
赵祥; 张师; 周毅博; 孟祥辉; 于昊; 王鹤萤
2015-01-01
风火打捆通过交直流混联外送电能已成为目前大规模风电基地比较常用的能源输送方式。在这种输送方式中，交直流混联、风电输送功率占总输送功率的比例和风电机组的类型等都会对风火打捆送端系统的暂态稳定性产生影响。在建立风电场模型、控制系统模型和混联输电系统模型的基础上，分析交直流混联对暂态稳定性的影响，研究不同风电机组类型对暂态稳定的影响，研究风电输出功率所占比例的改变对送端暂态稳定的影响。最后，通过分析得出：双馈感应发电机与常规火电机组打捆系统暂态稳定性好于另外两种类型风电机组；且双馈感应发电机在保证原动机出力稳定的情况下增加配比，有利于火电机组的功角稳定性。%Since wind power is explored on a large scale, it is a regular way for power transmission that the electricity generated from wind-thermal base is transmitted via AC/DC transmission system. The AC/DC transmission, the proportion of wind power to the total transmission power and the different kinds of wind turbine generators can influence the transient stability of the AC/DC transmission system with wind-thermal combined generation. First, the wind farm models, control system models and hybrid transmission models are founded. Then, the influences of AC/DC transmission system upon the transient stability are analyzed, and the influence of different kinds of wind turbine generators and the change of wind power proportion upon the transient stability is studied. At last, it is concluded through analysis that the transient stability of double fed induction generator (DFIG) and conventional wind generator bundled with thermal generation are better than the two other wind turbine generators, and while ensuring stable mechanical output, increasing proportion of DFIG will benefit the angle stability of thermal generators.
Sexually Transmitted Infections
LE Nicolle
2005-01-01
Full Text Available Sexually transmitted infections (STIs other than HIV have reappeared as an important public health problem in developed countries (1. In the late 1970s and early 1980s, research and treatment of the 'classic' STIs - gonorrhea, syphilis and chlamydia - were a major focus of infectious diseases practice and research. There were large outbreaks of syphilis in parts of Canada (2, penicillin-resistant Neisseria gonorrhoeae was a concern (3, and high rates of Chlamydia trachomatis infection with complications of pelvic inflammatory disease and ectopic pregnancy were being reported (4,5. Then, HIV infection emerged, with its spectre of a wasting, early death. There was no effective treatment, and safe sexual practices were embraced and adhered to by high-risk populations as the only effective way to avoid infection. These practices effectively prevented other STIs; rates of syphilis, gonorrhea and chlamydia infection plummeted in developed countries (5. For at least a decade, it appeared that HIV might be an end to all STIs, at least for some parts of the world. STIs continued unabated in developing countries, as many epidemiological and therapeutic studies explored the association of STIs with HIV infection.
Difference Antenna Selection and Power Allocation for Wireless Cognitive Systems
Wang, Yue
2010-01-01
In this paper, we propose an antenna selection method in a wireless cognitive radio (CR) system, namely difference selection, whereby a single transmit antenna is selected at the secondary transmitter out of $M$ possible antennas such that the weighted difference between the channel gains of the data link and the interference link is maximized. We analyze mutual information and outage probability of the secondary transmission in a CR system with difference antenna selection, and propose a method of optimizing these performance metrics of the secondary data link subject to practical constraints on the peak secondary transmit power and the average interference power as seen by the primary receiver. The optimization is performed over two parameters: the peak secondary transmit power and the difference selection weight $\\delta\\in [0, 1]$. We show that, difference selection using the optimized parameters determined by the proposed method can be, in many cases of interest, superior to a so called ratio selection me...
Medications for Sexually Transmitted Infections
... Genitals and Urinary Tract Glands & Growth Head Neck & Nervous System Heart Infections Learning Disabilities Obesity Orthopedic Prevention Sexually Transmitted Skin Tobacco Treatments Injuries & ...
A Novel Three-Dimensional Beamforming Antenna Array for Wireless Power Focusing
Mohammad A. Safar
2016-01-01
Full Text Available An antenna array capable of focusing the power transmitted to a specified point in space is modeled and simulated. This array will serve best for wireless power transmission applications where one of the goals is to maximize the power transfer efficiency. The array consists of 100 dipole antennas with each antenna transmitting a sum of 50 signals where each signal has a different frequency. This difference in frequency gives an additional degree of freedom that allows the overall beam pattern to be focused to a point in space instead of just a direction. The same array structure is also capable of transmitting power to multiple points in space which is promising when it comes to powering multiple points of interest.
Janusz Brzozowski
2014-05-01
Full Text Available The atoms of a regular language are non-empty intersections of complemented and uncomplemented quotients of the language. Tight upper bounds on the number of atoms of a language and on the quotient complexities of atoms are known. We introduce a new class of regular languages, called the maximally atomic languages, consisting of all languages meeting these bounds. We prove the following result: If L is a regular language of quotient complexity n and G is the subgroup of permutations in the transition semigroup T of the minimal DFA of L, then L is maximally atomic if and only if G is transitive on k-subsets of 1,...,n for 0 <= k <= n and T contains a transformation of rank n-1.
Andersen, Klaus Ejner
1985-01-01
Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline with...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....
Zak, Michail
2008-01-01
A report discusses an algorithm for a new kind of dynamics based on a quantum- classical hybrid-quantum-inspired maximizer. The model is represented by a modified Madelung equation in which the quantum potential is replaced by different, specially chosen 'computational' potential. As a result, the dynamics attains both quantum and classical properties: it preserves superposition and entanglement of random solutions, while allowing one to measure its state variables, using classical methods. Such optimal combination of characteristics is a perfect match for quantum-inspired computing. As an application, an algorithm for global maximum of an arbitrary integrable function is proposed. The idea of the proposed algorithm is very simple: based upon the Quantum-inspired Maximizer (QIM), introduce a positive function to be maximized as the probability density to which the solution is attracted. Then the larger value of this function will have the higher probability to appear. Special attention is paid to simulation of integer programming and NP-complete problems. It is demonstrated that the problem of global maximum of an integrable function can be found in polynomial time by using the proposed quantum- classical hybrid. The result is extended to a constrained maximum with applications to integer programming and TSP (Traveling Salesman Problem).
Hamza, Doha
2015-02-13
We propose a three-message superposition coding scheme in a cognitive radio relay network exploiting active cooperation between primary and secondary users. The primary user is motivated to cooperate by substantial benefits it can reap from this access scenario. Specifically, the time resource is split into three transmission phases: The first two phases are dedicated to primary communication, while the third phase is for the secondary’s transmission. We formulate two throughput maximization problems for the secondary network subject to primary user rate constraints and per-node power constraints with respect to the time durations of primary transmission and the transmit power of the primary and the secondary users. The first throughput maximization problem assumes a partial power constraint such that the secondary power dedicated to primary cooperation, i.e. for the first two communication phases, is fixed apriori. In the second throughput maximization problem, a total power constraint is assumed over the three phases of communication. The two problems are difficult to solve analytically when the relaying channel gains are strictly greater than each other and strictly greater than the direct link channel gain. However, mathematically tractable lowerbound and upperbound solutions can be attained for the two problems. For both problems, by only using the lowerbound solution, we demonstrate significant throughput gains for both the primary and the secondary users through this active cooperation scheme. We find that most of the throughput gains come from minimizing the second phase transmission time since the secondary nodes assist the primary communication during this phase. Finally, we demonstrate the superiority of our proposed scheme compared to a number of reference schemes that include best relay selection, dual-hop routing, and an interference channel model.
Simultaneous Transmit and Receive Performance of an 8-Channel Digital Phased Array
2017-01-16
Receive (STAR) could provide significant benefits for many applications including communications, radar, spectral sens- ing, and multifunctional...shown in Fig . 1. Transmit digital beamforming is used to reduce the total coupled power at each receive element, allowing the receive array to maintain...Canceller Receive Digital Beamfomer Isolated Receive SignalTransmit Signal ALSTAR Transmit Elements ALSTAR Receive Elements ... ... Fig . 1
Transfusion-transmitted Chagas' disease.
Wendel, S
1998-11-01
Transfusion-transmitted Chagas' disease has been recognized since 1952. Until recently, no cases were reported outside of Latin America. However, emigration during the past 20 years expanded its transfusional geographic borders to North America. Trypanosoma cruzi-infected donors usually are asymptomatic, often for a lifetime. This situation complicates donor screening, particularly in regions where blood bank personnel are not familiar with the risk factors and natural history of this transfusion-transmitted infection. This review addresses the main aspects of epidemiology, risks of infection, clinical symptoms in donors and recipients, preventive measures, and blood donor screening to prevent transfusion-transmitted Chagas' disease.
Statistics, Uncertainty, and Transmitted Variation
Wendelberger, Joanne Roth [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
2014-11-05
The field of Statistics provides methods for modeling and understanding data and making decisions in the presence of uncertainty. When examining response functions, variation present in the input variables will be transmitted via the response function to the output variables. This phenomenon can potentially have significant impacts on the uncertainty associated with results from subsequent analysis. This presentation will examine the concept of transmitted variation, its impact on designed experiments, and a method for identifying and estimating sources of transmitted variation in certain settings.
Gradient dynamics and entropy production maximization
Janečka, Adam
2016-01-01
Gradient dynamics describes irreversible evolution by means of a dissipation potential, which leads to several advantageous features like Maxwell--Onsager relations, distinguishing between thermodynamic forces and fluxes or geometrical interpretation of the dynamics. Entropy production maximization is a powerful tool for predicting constitutive relations in engineering. In this paper, both approaches are compared and their shortcomings and advantages are discussed.
Weighted Sum-Rate Maximization Using Weighted MMSE for MIMO-BC Beamforming Design
Christensen, Søren; De Carvalho, Elisabeth; Agarwal, Rajiv
2009-01-01
This paper studies linear transmit filter design for weighted sum-rate (WSR) maximization in the multiple input multiple output broadcast channel (MIMO-BC). The problem of finding the optimal transmit filter is non-convex and intractable to solve using low complexity methods. Motivated by recent ...
An Energy-Efficient MIMO Algorithm with Receive Power Constraint
Glazunov, Andrés Alayón
2012-01-01
We consider the energy-efficiency of Multiple-Input Multiple-Output (MIMO) systems with constrained received power rather than constrained transmit power. A Energy-Efficient Water-Filling (EEWF) algorithm that maximizes the ratio of the transmission rate to the total transmit power has been derived. The EEWF power allocation policy establishes a trade-off between the transmission rate and the total transmit power under the total receive power constraint. The static and the uncorrelated fast fading Rayleigh channels have been considered, where the maximization is performed on the instantaneous realization of the channel assuming perfect information at both the transmitter and the receiver with equal number of antennas. We show, based on Monte Carlo simulations that the energy-efficiency provided by the EEWF algorithm can be more than an order of magnitude greater than the energy-efficiency corresponding to capacity achieving Water-Filling (WF) algorithm. We also show that the energy-efficiency increases with b...
Brandes, U; Gaertler, M; Goerke, R; Hoefer, M; Nikoloski, Z; Wagner, D
2006-01-01
Several algorithms have been proposed to compute partitions of networks into communities that score high on a graph clustering index called modularity. While publications on these algorithms typically contain experimental evaluations to emphasize the plausibility of results, none of these algorithms has been shown to actually compute optimal partitions. We here settle the unknown complexity status of modularity maximization by showing that the corresponding decision version is NP-complete in the strong sense. As a consequence, any efficient, i.e. polynomial-time, algorithm is only heuristic and yields suboptimal partitions on many instances.
Integrated reconfigurable high-voltage transmitting circuit for CMUTs
Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger
2015-01-01
In this paper a high-voltage transmitting circuit aimed for capacitive micromachined ultrasonic transducers (CMUTs) used in scanners for medical applications is designed and implemented in a 0.35 μm high-voltage CMOS process. The transmitting circuit is reconfigurable externally making it able...... performance. The design occupies an on-chip area of 0.938 mm2 and the power consumption of a 128-element transmitting circuit array that would be used in an portable ultrasound scanner is found to be a maximum of 181 mW....
Integrated reconfigurable high-voltage transmitting circuit for CMUTs
Llimos Muntal, Pere; Larsen, Dennis Øland; Jørgensen, Ivan Harald Holger;
2015-01-01
In this paper a high-voltage transmitting circuit aimed for capacitive micromachined ultrasonic transducers (CMUTs) used in scanners for medical applications is designed and implemented in a 0.35 μm high-voltage CMOS process. The transmitting circuit is reconfigurable externally making it able...... performance. The design occupies an on-chip area of 0.938 mm2 and the power consumption of a 128-element transmitting circuit array that would be used in an portable ultrasound scanner is found to be a maximum of 181 mW....
Maximizing without difficulty: A modified maximizing scale and its correlates
Linda Lai
2010-01-01
This article presents several studies that replicate and extend previous research on maximizing. A modified scale for measuring individual maximizing tendency is introduced. The scale has adequate psychometric properties and reflects maximizers' aspirations for high standards and their preference for extensive alternative search, but not the decision difficulty aspect included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cogniti...
M. Marocolo
2007-02-01
Full Text Available Increased heart rate variability (HRV and high-frequency content of the terminal region of the ventricular activation of signal-averaged ECG (SAECG have been reported in athletes. The present study investigates HRV and SAECG parameters as predictors of maximal aerobic power (VO2max in athletes. HRV, SAECG and VO2max were determined in 18 high-performance long-distance (25 ± 6 years; 17 males runners 24 h after a training session. Clinical visits, ECG and VO2max determination were scheduled for all athletes during thew training period. A group of 18 untrained healthy volunteers matched for age, gender, and body surface area was included as controls. SAECG was acquired in the resting supine position for 15 min and processed to extract average RR interval (Mean-RR and root mean squared standard deviation (RMSSD of the difference of two consecutive normal RR intervals. SAECG variables analyzed in the vector magnitude with 40-250 Hz band-pass bi-directional filtering were: total and 40-µV terminal (LAS40 duration of ventricular activation, RMS voltage of total (RMST and of the 40-ms terminal region of ventricular activation. Linear and multivariate stepwise logistic regressions oriented by inter-group comparisons were adjusted in significant variables in order to predict VO2max, with a P < 0.05 considered to be significant. VO2max correlated significantly (P < 0.05 with RMST (r = 0.77, Mean-RR (r = 0.62, RMSSD (r = 0.47, and LAS40 (r = -0.39. RMST was the independent predictor of VO2max. In athletes, HRV and high-frequency components of the SAECG correlate with VO2max and the high-frequency content of SAECG is an independent predictor of VO2max.
HEMI: Hyperedge Majority Influence Maximization
Gangal, Varun; Narayanam, Ramasuri
2016-01-01
In this work, we consider the problem of influence maximization on a hypergraph. We first extend the Independent Cascade (IC) model to hypergraphs, and prove that the traditional influence maximization problem remains submodular. We then present a variant of the influence maximization problem (HEMI) where one seeks to maximize the number of hyperedges, a majority of whose nodes are influenced. We prove that HEMI is non-submodular under the diffusion model proposed.
Andersen, Klaus Ejner
1985-01-01
Guinea pig maximization tests (GPMT) with chlorocresol were performed to ascertain whether the sensitization rate was affected by minor changes in the Freund's complete adjuvant (FCA) emulsion used. Three types of emulsion were evaluated: the oil phase was mixed with propylene glycol, saline...... with 30% (v/v) ethanol or saline, respectively. Relative viscosity was used as one measure of physical properties of the emulsion. Higher degrees of sensitization (but not rates) were obtained at the 48 h challenge reading with the oil/propylene glycol and oil/saline + ethanol emulsions compared...... to the saline/oil emulsion. Placing of the challenge patches affected the response, as simultaneous chlorocresol challenge on the flank located 2 cm closer to the abdomen than the usual challenge site gave decreased reactions....
End-to-end interstellar communication system design for power efficiency
Messerschmitt, David G
2013-01-01
Interstellar radio communication accounting for known impairments due to radio propagation in the interstellar medium (attenuation, noise, dispersion, and scattering) and motion is studied. Large propagation losses and large transmitted powers motivate us to maximize the power efficiency, defined as the ratio of information rate to average signal power. The fundamental limit on power efficiency is determined. The power efficiency for narrow-bandwidth signals assumed in many current SETI searches has a penalty in power efficiency of four to five orders of magnitude. A set of five power-efficient design principles can asymptotically approach the fundamental limit, and in practice increase the power efficiency by three to four orders of magnitude. The most fundamental is to trade higher bandwidth for lower average power. In addition to improving the power efficiency, average power can be reduced by lowering the information rate. The resulting low-power signals have characteristics diametrically opposite to those...
Transfusional transmitted viruses in pregnancy.
Eleftheriou, A; Kalakoutis, G; Pavlides, N
1998-01-01
Blood has long been recognized as a vehicle for transmission of infectious organisms and as molecular laboratory technology has advanced, a seemingly endless array of infectious agents has occasionally been documented to be blood transmitted. Transfusion associated hepatitis (TAH) has been the most common serious consequence of blood transfusion although in recent years this has been significantly reduced (blood donor screening, blood processing, etc.). Thalassaemia major is classically associated with increased susceptibility to infections caused by those agents that are blood transmitted such as HBV, HCV, HIV, CMV, HPV B-19 (frequency rates vary from country to country). Monitoring the prevalence of transfusion transmitted infections in thalassaemics has been in recent years an indispensable part of their clinical management protocol. As a number of these viruses have been documented to be efficiently transmitted through the vertical route, the issue of blood transmitted viral infection monitoring becomes particularly important in order to provide protection or treatment both to the pregnant thalassaemic patient herself and to her foetus/newborn. Hepatitis (mainly B and C) and HIV in the obstetric thalassaemic is what the clinician is faced with most frequently. Although preventative measures have been very successful in the case of HBV infection and recently to an encouraging extent in the case of HIV (recommendations have been constructed), the mechanisms and frequency of HCV vertical transmission as well as the clinical outcome of children born to HCV carriers are not yet completely clarified. No vaccines are available and HIGB or antivirals do not appear to offer protection to the foetus against infection with HCV. Thalassaemics are frequently seropositive to markers of other transfusion transmitted viruses, such as CMV and HPV B-19, particularly by the age of pregnancy. Infection with a second or multiple strains as well as reactivation of existing CMV
MAXIMS VIOLATIONS IN LITERARY WORK
Widya Hanum Sari Pertiwi
2015-12-01
Full Text Available This study was qualitative research action that focuses to find out the flouting of Gricean maxims and the functions of the flouting in the tales which are included in collection of children literature entitled My Giant Treasury of Stories and Rhymes. The objective of the study is generally to identify the violation of maxims of quantity, quality, relevance, and manner in the data sources and also to analyze the use of the flouting in the tales which are included in the book. Qualitative design using categorizing strategies, specifically coding strategy, was applied. Thus, the researcher as the instrument in this investigation was selecting the tales, reading them, and gathering every item which reflects the violation of Gricean maxims based on some conditions of flouting maxims. On the basis of the data analysis, it was found that the some utterances in the tales, both narration and conversation, flouting the four maxims of conversation, namely maxim of quality, maxim of quantity, maxim of relevance, and maxim of manner. The researcher has also found that the flouting of maxims has one basic function that is to encourage the readers’ imagination toward the tales. This one basic function is developed by six others functions: (1 generating specific situation, (2 developing the plot, (3 enlivening the characters’ utterance, (4 implicating message, (5 indirectly characterizing characters, and (6 creating ambiguous setting. Keywords: children literature, tales, flouting maxims
Swanepoel, Konrad J
2011-01-01
A subset of a normed space X is called equilateral if the distance between any two points is the same. Let m(X) be the smallest possible size of an equilateral subset of X maximal with respect to inclusion. We first observe that Petty's construction of a d-dimensional X of any finite dimension d >= 4 with m(X)=4 can be generalised to show that m(X\\oplus_1\\R)=4 for any X of dimension at least 2 which has a smooth point on its unit sphere. By a construction involving Hadamard matrices we then show that both m(\\ell_p) and m(\\ell_p^d) are finite and bounded above by a function of p, for all 1 1 such that m(X) <= d+1 for all d-dimensional X with Banach-Mazur distance less than c from \\ell_p^d. Using Brouwer's fixed-point theorem we show that m(X) <= d+1 for all d-\\dimensional X with Banach-Mazur distance less than 3/2 from \\ell_\\infty^d. A graph-theoretical argument furthermore shows that m(\\ell_\\infty^d)=d+1. The above results lead us to conjecture that m(X) <= 1+\\dim X.
Unified Maximally Natural Supersymmetry
Huang, Junwu
2016-01-01
Maximally Natural Supersymmetry, an unusual weak-scale supersymmetric extension of the Standard Model based upon the inherently higher-dimensional mechanism of Scherk-Schwarz supersymmetry breaking (SSSB), possesses remarkably good fine tuning given present LHC limits. Here we construct a version with precision $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ unification: $\\sin^2 \\theta_W(M_Z) \\simeq 0.231$ is predicted to $\\pm 2\\%$ by unifying $SU(2)_{\\rm L} \\times U(1)_{\\rm Y} $ into a 5D $SU(3)_{\\rm EW}$ theory at a Kaluza-Klein scale of $1/R_5 \\sim 4.4\\,{\\rm TeV}$, where SSSB is simultaneously realised. Full unification with $SU(3)_{\\rm C}$ is accommodated by extending the 5D theory to a $N=4$ supersymmetric $SU(6)$ gauge theory on a 6D rectangular orbifold at $1/R_6 \\sim 40 \\,{\\rm TeV}$. TeV-scale states beyond the SM include exotic charged fermions implied by $SU(3)_{\\rm EW}$ with masses lighter than $\\sim 1.2\\,{\\rm TeV}$, and squarks in the mass range $1.4\\,{\\rm TeV} - 2.3\\,{\\rm TeV}$, providing distinct signature...
Greedy SINR Maximization in Collaborative Multibase Wireless Systems
Popescu Otilia
2004-01-01
Full Text Available We present a codeword adaptation algorithm for collaborative multibase wireless systems. The system is modeled with multiple inputs and multiple outputs (MIMO in which information is transmitted using multicode CDMA, and codewords are adapted based on greedy maximization of the signal-to-interference-plus-noise ratio. The procedure monotonically increases the sum capacity and, when repeated iteratively for all codewords in the system, converges to a fixed point. Fixed-point properties and a connection with sum capacity maximization, along with a discussion of simulations that corroborate the basic analytic results, are included in the paper.
Worst-Case Energy Efficiency Maximization in a 5G Massive MIMO-NOMA System.
Chinnadurai, Sunil; Selvaprabhu, Poongundran; Jeong, Yongchae; Jiang, Xueqin; Lee, Moon Ho
2017-09-18
In this paper, we examine the robust beamforming design to tackle the energy efficiency (EE) maximization problem in a 5G massive multiple-input multiple-output (MIMO)-non-orthogonal multiple access (NOMA) downlink system with imperfect channel state information (CSI) at the base station. A novel joint user pairing and dynamic power allocation (JUPDPA) algorithm is proposed to minimize the inter user interference and also to enhance the fairness between the users. This work assumes imperfect CSI by adding uncertainties to channel matrices with worst-case model, i.e., ellipsoidal uncertainty model (EUM). A fractional non-convex optimization problem is formulated to maximize the EE subject to the transmit power constraints and the minimum rate requirement for the cell edge user. The designed problem is difficult to solve due to its nonlinear fractional objective function. We firstly employ the properties of fractional programming to transform the non-convex problem into its equivalent parametric form. Then, an efficient iterative algorithm is proposed established on the constrained concave-convex procedure (CCCP) that solves and achieves convergence to a stationary point of the above problem. Finally, Dinkelbach's algorithm is employed to determine the maximum energy efficiency. Comprehensive numerical results illustrate that the proposed scheme attains higher worst-case energy efficiency as compared with the existing NOMA schemes and the conventional orthogonal multiple access (OMA) scheme.
Elmholdt, Claus Westergård; Fogsgaard, Morten
2016-01-01
In this chapter, we will explore the dynamics of power in processes of creativity, and show its paradoxical nature as both a bridge and a barrier to creativity in organisations. Recent social psychological experimental research (Slighte, de Dreu & Nijstad, 2011) on the relation between power...... and creativity suggests that when managers give people the opportunity to gain power and explicate that there is reason to be more creative, people will show a boost in creative behaviour. Moreover, this process works best in unstable power hierarchies, which implies that power is treated as a negotiable...... and floating source for empowering people in the organisation. We will explore and discuss here the potentials, challenges and pitfalls of power in relation to creativity in the life of organisations today. The aim is to demonstrate that power struggles may be utilised as constructive sources of creativity...
Utility maximization in incomplete markets with default
Lim, Thomas
2008-01-01
We adress the maximization problem of expected utility from terminal wealth. The special feature of this paper is that we consider a financial market where the price process of risky assets can have a default time. Using dynamic programming, we characterize the value function with a backward stochastic differential equation and the optimal portfolio policies. We separately treat the cases of exponential, power and logarithmic utility.
Joint switched multi-spectrum and transmit antenna diversity for spectrum sharing systems
Sayed, Mostafa M.
2013-10-01
In spectrum sharing systems, a secondary user (SU) is allowed to share the spectrum with a primary (licensed) network under the condition that the interference observed at the receivers of the primary users (PU-Rxs) is below a predetermined level. In this paper, we consider a secondary network comprised of a secondary transmitter (SU-Tx) equipped with multiple antennas and a single-antenna secondary receiver (SU-Rx) sharing the same spectrum with multiple primary users (PUs), each with a distinct spectrum. We develop transmit antenna diversity schemes at the SU-Tx that exploit the multi-spectrum diversity provided by the existence of multiple PUs so as to optimize the signal-to-noise ratio (SNR) at the SU-Rx. In particular, assuming bounded transmit power at the SU-Tx, we develop switched selection schemes that select the primary spectrum and the SU-Tx transmit antenna that maintain the SNR at the SU-Rx above a specific threshold. Assuming Rayleigh fading channels and binary phase-shift keying (BPSK) transmission, we derive the average bit-error-rate (BER) and average feedback load expressions for the proposed schemes. For the sake of comparison, we also derive a BER expression for the optimal selection scheme that selects the best antenna/spectrum pair that maximizes the SNR at the SU-Rx, in exchange of high feedback load and switching complexity. Finally, we show that our analytical results are in perfect agreement with the simulation results. © 2013 IEEE.
Maximal subgroups of finite groups
S. Srinivasan
1990-01-01
Full Text Available In finite groups maximal subgroups play a very important role. Results in the literature show that if the maximal subgroup has a very small index in the whole group then it influences the structure of the group itself. In this paper we study the case when the index of the maximal subgroups of the groups have a special type of relation with the Fitting subgroup of the group.
Finding Maximal Quasiperiodicities in Strings
Brodal, Gerth Stølting; Pedersen, Christian N. S.
2000-01-01
of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...
Maximizing Entropy over Markov Processes
Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis
2013-01-01
computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of an system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...
Maximizing entropy over Markov processes
Biondi, Fabrizio; Legay, Axel; Nielsen, Bo Friis
2014-01-01
computation reduces to finding a model of a specification with highest entropy. Entropy maximization for probabilistic process specifications has not been studied before, even though it is well known in Bayesian inference for discrete distributions. We give a characterization of global entropy of a process...... as a reward function, a polynomial algorithm to verify the existence of a system maximizing entropy among those respecting a specification, a procedure for the maximization of reward functions over Interval Markov Chains and its application to synthesize an implementation maximizing entropy. We show how...
Energy-efficient power control for OFDMA cellular networks
Sboui, Lokman
2016-12-24
In this paper, we study the energy efficiency (EE) of orthogonal frequency-division multiple access (OFDMA) cellular networks. Our objective is to present a power allocation scheme that maximizes the EE of downlink communications. We propose a novel explicit expression of the optimal power allocation to each subcarrier. We also present the power control when the transmit power is limited by power budget constraint or/and minimal rate constraint and we highlight the occurrence of some transmission outage events depending on the constraints\\' parameters. In the numerical results, we show that our proposed power control improves the EE especially at high power budget regime and low minimal rate regime. In addition, we show that having a higher number of subcarriers enhances the OFDMA EE.
Capacity Maximizing Constellations
Barsoum, Maged; Jones, Christopher
2010-01-01
Some non-traditional signal constellations have been proposed for transmission of data over the Additive White Gaussian Noise (AWGN) channel using such channel-capacity-approaching codes as low-density parity-check (LDPC) or turbo codes. Computational simulations have shown performance gains of more than 1 dB over traditional constellations. These gains could be translated to bandwidth- efficient communications, variously, over longer distances, using less power, or using smaller antennas. The proposed constellations have been used in a bit-interleaved coded modulation system employing state-ofthe-art LDPC codes. In computational simulations, these constellations were shown to afford performance gains over traditional constellations as predicted by the gap between the parallel decoding capacity of the constellations and the Gaussian capacity
Sexually transmitted diseases and anorectum.
VAN KEMSEKE, Catherine
2009-01-01
Sexually transmitted diseases (STD) are a major public health problem because their incidence is increasing worldwide despite prevention campaigns and because they raise the risk of HIV infection. Anorectal localisations of STD are common among men who have sex with men (MSM) but can also be seen among heterosexuals (men or women). Transmission of such infections is due to anal sex or to other sexual behaviours like "fisting". Although some pathogens (like Human Papillomavirus-HPV) are common...
Tang Zhenzhou; Hu Qian; Yu Guanding
2008-01-01
In this letter, an Opportunistic Interference Cancellation (OIC) is first introduced as a rate control strategy for secondary user in cognitive wireless networks. Based on the OIC rate control method, an optimal power control strategy for multichannel cognitive wireless networks is proposed. The algorithm aims to maximize the total transmit rate of cognitive user through appropriately controlling the transmit power of each subchannel under the constraint that the interference temperature at the primary receiver is below a certain threshold. Three suboptimal power control methods, namely Equal Power Transmission (EPT), Equal Rate Transmission (ERT) and Equal Interference Transmission (EIT), are also proposed. The performances of the proposed power control methods are compared through numerical simulations.
Power-Efficient Ultra-Wideband Waveform Design Considering Radio Channel Effects
Yipeng Liu
2011-04-01
Full Text Available This paper presents a power-efficient maskconstrained ultra-wideband (UWB waveform design with radio channel effects taken into consideration. Based on a finite impulse response (FIR filter, we develop a convex optimization model with respect to the autocorrelation of the filter coefficients to optimize the transmitted signal power spectrum, subject to a regulatory emission mask. To improve power efficiency, effects of transmitter radio frequency (RF components are included in the optimization of the transmitter-output waveform, and radio propagation effects are considered for obtaining the most efficient waveform at the receiver. Optimum coefficients of the FIR filter are obtained through spectral factorization of their autocorrelations. Simulation results show that the proposed method is able to maximize the transmitted UWB signal power under mask constraints set by regulatory authorities, while mitigating the power loss caused by channel attenuations.
A FAST BIT-LOADING ALGORITHM FOR HIGH SPEED POWER LINE COMMUNICATIONS
Zhang Shengqing; Zhao Li; Zou Cairong
2012-01-01
Adaptive bit-loading is a key technology in high speed power line communications with the Orthogonal Frequency Division Multiplexing (OFDM) modulation technology.According to the real situation of the transmitting power spectrum limited in high speed power line communications,this paper explored the adaptive bit loading algorithm to maximize transmission bit number when transmitting power spectral density and bit error rate are not exceed upper limit.With the characteristics of the power line channel,first of all,it obtains the optimal bit loading algorithm,and then provides the improved algorithm to reduce the computational complexity.Based on the analysis and simulation,it offers a non-iterative bit allocation algorithm,and finally the simulation shows that this new algorithm can greatly reduce the computational complexity,and the actual bit allocation results close to optimal.
Gonzalez-Sanchez, Jon
2010-01-01
Let $w = w(x_1,..., x_n)$ be a word, i.e. an element of the free group $F =$ on $n$ generators $x_1,..., x_n$. The verbal subgroup $w(G)$ of a group $G$ is the subgroup generated by the set $\\{w (g_1,...,g_n)^{\\pm 1} | g_i \\in G, 1\\leq i\\leq n \\}$ of all $w$-values in $G$. We say that a (finite) group $G$ is $w$-maximal if $|G:w(G)|> |H:w(H)|$ for all proper subgroups $H$ of $G$ and that $G$ is hereditarily $w$-maximal if every subgroup of $G$ is $w$-maximal. In this text we study $w$-maximal and hereditarily $w$-maximal (finite) groups.
MIMO Radar Transmit Beampattern Design for DOA Estimation with Sidelobe Suppression
Yuxiang Li
2016-01-01
Full Text Available We address the problem of transmit beamspace design for multiple-input multiple-output (MIMO radar with colocated antennas in direction-of-arrival (DOA estimation application. Three transmit beampattern sidelobe suppression strategies for designing the transmit beamspace matrix are introduced. The design of transmit beamspace matrix is based on minimizing the difference between a desired transmit beampattern and the actual one while keeping the sidelobe levels under control. Uniform elemental power distribution across the transmit antenna is guaranteed; at the same time, signal rotational invariance property is considered, which enables search-free based DOA estimation algorithms to be utilized at the receiver. The proposed optimization problems are nonconvex and are solved by using semidefinite programming relaxation technique. Moreover, the DOA estimation Cramer-Rao bound with transmit beamspace matrix is discussed. Simulation results show the superiority of the proposed techniques over the existing methods.
Maximizing without difficulty: A modified maximizing scale and its correlates
Lai, Linda
2010-01-01
... included in several previous studies. Based on this scale, maximizing is positively correlated with optimism, need for cognition, desire for consistency, risk aversion, intrinsic motivation, self-efficacy and perceived workload, whereas...
Maximizing and customer loyalty: Are maximizers less loyal?
Linda Lai
2011-06-01
Full Text Available Despite their efforts to choose the best of all available solutions, maximizers seem to be more inclined than satisficers to regret their choices and to experience post-decisional dissonance. Maximizers may therefore be expected to change their decisions more frequently and hence exhibit lower customer loyalty to providers of products and services compared to satisficers. Findings from the study reported here (N = 1978 support this prediction. Maximizers reported significantly higher intentions to switch to another service provider (television provider than satisficers. Maximizers' intentions to switch appear to be intensified and mediated by higher proneness to regret, increased desire to discuss relevant choices with others, higher levels of perceived knowledge of alternatives, and higher ego involvement in the end product, compared to satisficers. Opportunities for future research are suggested.
Are maximizers really unhappy? The measurement of maximizing tendency,
Dalia L. Diab
2008-06-01
Full Text Available Recent research suggesting that people who maximize are less happy than those who satisfice has received considerable fanfare. The current study investigates whether this conclusion reflects the construct itself or rather how it is measured. We developed an alternative measure of maximizing tendency that is theory-based, has good psychometric properties, and predicts behavioral outcomes. In contrast to the existing maximization measure, our new measure did not correlate with life (dissatisfaction, nor with most maladaptive personality and decision-making traits. We conclude that the interpretation of maximizers as unhappy may be due to poor measurement of the construct. We present a more reliable and valid measure for future researchers to use.
Principles of maximally classical and maximally realistic quantum mechanics
S M Roy
2002-08-01
Recently Auberson, Mahoux, Roy and Singh have proved a long standing conjecture of Roy and Singh: In 2-dimensional phase space, a maximally realistic quantum mechanics can have quantum probabilities of no more than + 1 complete commuting cets (CCS) of observables coexisting as marginals of one positive phase space density. Here I formulate a stationary principle which gives a nonperturbative deﬁnition of a maximally classical as well as maximally realistic phase space density. I show that the maximally classical trajectories are in fact exactly classical in the simple examples of coherent states and bound states of an oscillator and Gaussian free particle states. In contrast, it is known that the de Broglie–Bohm realistic theory gives highly nonclassical trajectories.
Integrated differential high-voltage transmitting circuit for CMUTs
Llimos Muntal, Pere; Larsen, Dennis Øland; Farch, Kjartan
2015-01-01
In this paper an integrated differential high-voltage transmitting circuit for capacitive micromachined ultrasonic transducers (CMUTs) used in portable ultrasound scanners is designed and implemented in a 0.35 μm high-voltage process. Measurements are performed on the integrated circuit in order...... to assess its performance. The circuit generates pulses at differential voltage levels of 60V, 80V and 100 V, a frequency up to 5MHz and a measured driving strength of 1.75 V/ns with the CMUT connected. The total on-chip area occupied by the transmitting circuit is 0.18 mm2 and the power consumption...
Renato Aparecido Corrêa Caritá
2009-10-01
Full Text Available O principal objetivo deste estudo foi comparar a intensidade correspondente à máxima fase estável de lactato (MLSS e a potência crítica (PC durante o ciclismo em indivíduos bem treinados. Seis ciclistas do sexo masculino (25,5 ± 4,4 anos, 68,8 ± 3,0kg, 173,0 ± 4,0cm realizaram em diferentes dias os seguintes testes: exercício incremental até a exaustão para a determinação do pico de consumo de oxigênio (VO2pico e sua respectiva intensidade (IVO2pico; cinco a sete testes de carga constante para a determinação da MLSS e da PC; e um exercício até a exaustão na PC. A MLSS foi considerada com a maior intensidade de exercício onde a concentração de lactato não aumentou mais do que 1mM entre o 10º e o 30º min de exercício. Os valores individuais de potência (95, 100 e 110% IVO2pico e seu respectivo tempo máximo de exercício (Tlim foram ajustados a partir do modelo hiperbólico de dois parâmetros para a determinação da PC. Embora altamente correlacionadas (r = 0,99; p = 0,0001, a PC (313,5 ± 32,3W foi significantemente maior do que a MLLS (287,0 ± 37,8W (p = 0,0002. A diferença percentual da PC em relação à MLSS foi de 9,5 ± 3,1%. No exercício realizado na PC, embora tenha existido componente lento do VO2 (CL = 400,8 ± 267,0 ml.min-1, o VO2pico não foi alcançado (91,1 ± 3,3 %. Com base nesses resultados pode-se concluir que a PC e a MLSS identificam diferentes intensidades de exercício, mesmo em atletas com elevada aptidão aeróbia. Entretanto, o percentual da diferença entre a MLLS e PC (9% indica que relação entre esses dois índices pode depender da aptidão aeróbia. Durante o exercício realizado até a exaustão na PC, o CL que é desenvolvido não permite que o VO2pico seja alcançado.The main objective of this study was to compare the intensity corresponding to the maximal lactate steady state (MLSS and critical power (CP in well-trained cyclists. Six male cyclists (25.5 ± 4.4 years, 68.8 ± 3
Maximal strength training improves cycling economy in competitive cyclists.
Sunde, Arnstein; Støren, Oyvind; Bjerkaas, Marius; Larsen, Morten H; Hoff, Jan; Helgerud, Jan
2010-08-01
The purpose of the present study was to investigate the effect of maximal strength training on cycling economy (CE) at 70% of maximal oxygen consumption (Vo2max), work efficiency in cycling at 70% Vo2max, and time to exhaustion at maximal aerobic power. Responses in 1 repetition maximum (1RM) and rate of force development (RFD) in half-squats, Vo2max, CE, work efficiency, and time to exhaustion at maximal aerobic power were examined. Sixteen competitive road cyclists (12 men and 4 women) were randomly assigned into either an intervention or a control group. Thirteen (10 men and 3 women) cyclists completed the study. The intervention group (7 men and 1 woman) performed half-squats, 4 sets of 4 repetitions maximum, 3 times per week for 8 weeks, as a supplement to their normal endurance training. The control group continued their normal endurance training during the same period. The intervention manifested significant (p < 0.05) improvements in 1RM (14.2%), RFD (16.7%), CE (4.8%), work efficiency (4.7%), and time to exhaustion at pre-intervention maximal aerobic power (17.2%). No changes were found in Vo2max or body weight. The control group exhibited an improvement in work efficiency (1.4%), but this improvement was significantly (p < 0.05) smaller than that in the intervention group. No changes from pre- to postvalues in any of the other parameters were apparent in the control group. In conclusion, maximal strength training for 8 weeks improved CE and efficiency and increased time to exhaustion at maximal aerobic power among competitive road cyclists, without change in maximal oxygen uptake, cadence, or body weight. Based on the results from the present study, we advise cyclists to include maximal strength training in their training programs.
Zika Mosquito Can Transmit Other Viruses, Too
... page: https://medlineplus.gov/news/fullstory_165752.html Zika Mosquito Can Transmit Other Viruses, Too 3-in- ... mosquito species that's the main carrier of the Zika virus might also transmit two other viruses -- chikungunya ...
Adaptive single-antenna transmit selection with interference suppression
Radaydeh, Redha Mahmoud Mesleh
2011-10-01
This paper studies the performance of adaptive transmit selection with co-channel interference suppression in multipath fading channels. The adaptive selection algorithms are configured for single-antenna bandwidth-efficient or power-efficient transmission with as low transmit channel estimations as possible. Due to the fact that the number of active co-channel interfering signals and their corresponding powers experience random behavior, the adaptation to channels conditions, assuming uniform buffer and traffic loading, is proposed to be jointly based on the transmit channels instantaneous signal-to-noise ratios (SNRs) and signal-to-interference-plus-noise ratios (SINRs). Two interference cancelation algorithms are considered. The first algorithm assumes that the receiver eliminates the impact of the strongest subset of interferers, whereas the second algorithm suggests random cancelation of interferers to further reduce processing complexity. The impact of outdated ordering of interferers powers on the efficiency of interference cancelation, and the effect of imperfect prediction of transmit channels for desired user adaptation are investigated. Analytical formulations for various performance measures and comparisons between the performance and processing complexity of different adaptation schemes are presented. © 2011 IEEE.
Efficient Transmit Beamspace Design for Search-Free Based DOA Estimation in MIMO Radar
Khabbazibasmenj, Arash; Hassanien, Aboulnasr; Vorobyov, Sergiy A.; Morency, Matthew W.
2014-03-01
In this paper, we address the problem of transmit beamspace design for multiple-input multiple-output (MIMO) radar with colocated antennas in application to direction-of-arrival (DOA) estimation. A new method for designing the transmit beamspace matrix that enables the use of search-free DOA estimation techniques at the receiver is introduced. The essence of the proposed method is to design the transmit beamspace matrix based on minimizing the difference between a desired transmit beampattern and the actual one under the constraint of uniform power distribution across the transmit array elements. The desired transmit beampattern can be of arbitrary shape and is allowed to consist of one or more spatial sectors. The number of transmit waveforms is even but otherwise arbitrary. To allow for simple search-free DOA estimation algorithms at the receive array, the rotational invariance property is established at the transmit array by imposing a specific structure on the beamspace matrix. Semi-definite relaxation is used to transform the proposed formulation into a convex problem that can be solved efficiently. We also propose a spatial-division based design (SDD) by dividing the spatial domain into several subsectors and assigning a subset of the transmit beams to each subsector. The transmit beams associated with each subsector are designed separately. Simulation results demonstrate the improvement in the DOA estimation performance offered by using the proposed joint and SDD transmit beamspace design methods as compared to the traditional MIMO radar technique.
Maximizing ROI with yield management
Neil Snyder
2001-01-01
.... the technology is based on the concept of yield management, which aims to sell the right product to the right customer at the right price and the right time therefore maximizing revenue, or yield...
Are CEOs Expected Utility Maximizers?
John List; Charles Mason
2009-01-01
Are individuals expected utility maximizers? This question represents much more than academic curiosity. In a normative sense, at stake are the fundamental underpinnings of the bulk of the last half-century's models of choice under uncertainty. From a positive perspective, the ubiquitous use of benefit-cost analysis across government agencies renders the expected utility maximization paradigm literally the only game in town. In this study, we advance the literature by exploring CEO's preferen...
Gaussian maximally multipartite entangled states
Facchi, Paolo; Lupo, Cosmo; Mancini, Stefano; Pascazio, Saverio
2009-01-01
We introduce the notion of maximally multipartite entangled states (MMES) in the context of Gaussian continuous variable quantum systems. These are bosonic multipartite states that are maximally entangled over all possible bipartitions of the system. By considering multimode Gaussian states with constrained energy, we show that perfect MMESs, which exhibit the maximum amount of bipartite entanglement for all bipartitions, only exist for systems containing n=2 or 3 modes. We further numerically investigate the structure of MMESs and their frustration for n <= 7.
All maximally entangling unitary operators
Cohen, Scott M. [Department of Physics, Duquesne University, Pittsburgh, Pennsylvania 15282 (United States); Department of Physics, Carnegie-Mellon University, Pittsburgh, Pennsylvania 15213 (United States)
2011-11-15
We characterize all maximally entangling bipartite unitary operators, acting on systems A and B of arbitrary finite dimensions d{sub A}{<=}d{sub B}, when ancillary systems are available to both parties. Several useful and interesting consequences of this characterization are discussed, including an understanding of why the entangling and disentangling capacities of a given (maximally entangling) unitary can differ and a proof that these capacities must be equal when d{sub A}=d{sub B}.
Salvio, Alberto; Strumia, Alessandro; Urbano, Alfredo
2016-01-01
Motivated by the 750 GeV diphoton excess found at LHC, we compute the maximal width into $\\gamma\\gamma$ that a neutral scalar can acquire through a loop of charged fermions or scalars as function of the maximal scale at which the theory holds, taking into account vacuum (meta)stability bounds. We show how an extra gauge symmetry can qualitatively weaken such bounds, and explore collider probes and connections with Dark Matter.
From entropy-maximization to equality-maximization: Gauss, Laplace, Pareto, and Subbotin
Eliazar, Iddo
2014-12-01
The entropy-maximization paradigm of statistical physics is well known to generate the omnipresent Gauss law. In this paper we establish an analogous socioeconomic model which maximizes social equality, rather than physical disorder, in the context of the distributions of income and wealth in human societies. We show that-on a logarithmic scale-the Laplace law is the socioeconomic equality-maximizing counterpart of the physical entropy-maximizing Gauss law, and that this law manifests an optimized balance between two opposing forces: (i) the rich and powerful, striving to amass ever more wealth, and thus to increase social inequality; and (ii) the masses, struggling to form more egalitarian societies, and thus to increase social equality. Our results lead from log-Gauss statistics to log-Laplace statistics, yield Paretian power-law tails of income and wealth distributions, and show how the emergence of a middle-class depends on the underlying levels of socioeconomic inequality and variability. Also, in the context of asset-prices with Laplace-distributed returns, our results imply that financial markets generate an optimized balance between risk and predictability.
Power Control for Maximum Throughput in Spectrum Underlay Cognitive Radio Networks
Tadrous, John; Nafie, Mohammed; El-Keyi, Amr
2010-01-01
We investigate power allocation for users in a spectrum underlay cognitive network. Our objective is to find a power control scheme that allocates transmit power for both primary and secondary users so that the overall network throughput is maximized while maintaining the quality of service (QoS) of the primary users greater than a certain minimum limit. Since an optimum solution to our problem is computationally intractable, as the optimization problem is non-convex, we propose an iterative algorithm based on sequential geometric programming, that is proved to converge to at least a local optimum solution. We use the proposed algorithm to show how a spectrum underlay network would achieve higher throughput with secondary users operation than with primary users operating alone. Also, we show via simulations that the loss in primary throughput due to the admission of the secondary users is accompanied by a reduction in the total primary transmit power.
On intermodulation beams of satellite DBF transmitting multibeam array antenna
Zhao, Hongmei; Wang, Huali; Mu, Shanxiang
2007-11-01
Digital beamforming (DBF) transmitting multibeam planar array antenna with nonlinear behaviors of solid-state power amplifiers (SSPA) is discussed. This paper investigates the intermodulation beams produced by the nonlinearity characteristics of the SSPA with multiple carrier components. The Shimbo model is simplified to describe the nonlinear behaviors of SSPA. The optimal SSPA input back-off (IBO) point which is given the desired the carrier and the intermodulatin ratio (C/IM) is simulated. And the tradeoffs between linearity and efficiency of the power amplifier which influence this IBO is also discussed, helping to selecting suitable SSPA device and reducing the dc power consumption in satellite array antenna system.
Notification of transfusion transmitted infection.
Choudhury, Lincoln P; Tetali, Shailaja
2008-01-01
The National Blood Policy of India, 2002, advocates the disclosure of results of transfusion transmitted infections (TTI) to blood donors. However, in the absence of well-defined notification processes, and in order to avoid serious consequences resulting from unguided disclosure, blood bank personnel discard blood that is TTI-positive. We report on a survey of 105 voluntary blood donors in Kerala. Only two out of three participants had filled the donor form in the last year. Only half were aware that the blood bank was supposed to inform them if they tested positive for TTI. Fifty-seven per cent of donors wanted to be informed every time they donated blood, irrespective of a positive or negative result.
Transfusion-transmitted parasitic infections
Singh Gagandeep
2010-01-01
Full Text Available The transmission of parasitic organisms through transfusion is relatively rare. Of the major transfusion-transmitted diseases, malaria is a major cause of TTIP in tropical countries whereas babesiosis and Chagas′ disease pose the greatest threat to donors in the USA In both cases, this is due to the increased number of potentially infected donors. There are no reliable serologic tests available to screen donors for any of these organisms and the focus for prevention remains on adherence to donor screening guidelines that address travel history and previous infection with the etiologic agent. One goal is the development of tests that are able to screen for and identify donors potentially infectious for parasitic infections without causing the deferral of a large number of non-infectious donors or significantly increasing costs. Ideally, methods to inactivate the infectious organism will provide an element of added safety to the blood supply.
Phased Array Transmit Antenna for a Satellite
Huggins, R. W.; Heisen, P. T.; Miller, G. E.; McMeen, D. J.; Perko, K. L.
1999-01-01
Active phased array antennas with electronically scanned beams offer advantages over high gain parabolic dish antennas currently used on spacecraft. Benefits include the elimination of deployable structures, no moving parts, and no torque disturbances that moving antennas impart to the spacecraft. The latter results in the conservation of spacecraft power, and the ability to take precision optical data while transmitting data. Such an antenna has been built under a contract from NASA Goddard Space Flight Center for the New Millennium Program EO- 1 satellite where it will act as the primary highspeed scientific data communication link. The antenna operates at X-band, has an integral controller and power conditioner, communicates with the spacecraft over a 1773 optical data bus, and is space qualified for low earth orbit (705 Km altitude). The nominal mission length is one year, and the operational requirement is for one 10 minute transmission a day over Spitsbergen, Norway. Details of the antenna and its performance will be described in the following paper.
Fourier-Based Transmit Beampattern Design Using MIMO Radar
Lipor, John
2014-05-01
In multiple-input multiple-output (MIMO) radar settings, it is often desirable to transmit power only to a given location or set of locations defined by a beampattern. Transmit waveform design is a topic that has received much attention recently, involving synthesis of both the signal covariance matrix,, as well as the actual waveforms. Current methods involve a two-step process of designing via iterative solutions and then using to generate waveforms that fulfill practical constraints such as having a constant-envelope or drawing from a finite alphabet. In this paper, a closed-form method to design for a uniform linear array is proposed that utilizes the discrete Fourier transform (DFT) coefficients and Toeplitz matrices. The resulting covariance matrix fulfills the practical constraints such as positive semidefiniteness and the uniformelemental power constraint and provides performance similar to that of iterative methods, which require a much greater computation time. Next, a transmit architecture is presented that exploits the orthogonality of frequencies at discrete DFT values to transmit a sum of orthogonal signals from each antenna. The resulting waveforms provide a lower mean-square error than current methods at a much lower computational cost, and a simulated detection scenario demonstrates the performance advantages achieved.
A. Garmroodi Asil
2017-09-01
To further reduce the sulfur dioxide emission of the entire refining process, two scenarios of acid gas or air preheats are investigated when either of them is used simultaneously with the third enrichment scheme. The maximum overall sulfur recovery efficiency and highest combustion chamber temperature is slightly higher for acid gas preheats but air preheat is more favorable because it is more benign. To the best of our knowledge, optimization of the entire GTU + enrichment section and SRU processes has not been addressed previously.
Throughput Optimal Policies for Energy Harvesting Wireless Transmitters with Non-Ideal Circuit Power
Xu, Jie
2012-01-01
Characterizing the fundamental tradeoffs for maximizing energy efficiency (EE) versus spectrum efficiency (SE) is a key problem in wireless communication. In this paper, we address this problem for a point-to-point additive white Gaussian noise (AWGN) channel with the transmitter powered solely via energy harvesting from the environment. In addition, we assume a practical on-off transmitter model with non-ideal circuit power, i.e., when the transmitter is on, its consumed power is the sum of the transmit power and a constant circuit power. Under this setup, we study the optimal transmit power allocation to maximize the average throughput over a finite horizon, subject to the time-varying energy constraint and the non-ideal circuit power consumption. First, we consider the off-line optimization under the assumption that the energy arrival time and amount are a priori known at the transmitter. Although this problem is non-convex due to the non-ideal circuit power, we show an efficient optimal solution that in g...
Algebraic curves of maximal cyclicity
Caubergh, Magdalena; Dumortier, Freddy
2006-01-01
The paper deals with analytic families of planar vector fields, studying methods to detect the cyclicity of a non-isolated closed orbit, i.e. the maximum number of limit cycles that can locally bifurcate from it. It is known that this multi-parameter problem can be reduced to a single-parameter one, in the sense that there exist analytic curves in parameter space along which the maximal cyclicity can be attained. In that case one speaks about a maximal cyclicity curve (mcc) in case only the number is considered and of a maximal multiplicity curve (mmc) in case the multiplicity is also taken into account. In view of obtaining efficient algorithms for detecting the cyclicity, we investigate whether such mcc or mmc can be algebraic or even linear depending on certain general properties of the families or of their associated Bautin ideal. In any case by well chosen examples we show that prudence is appropriate.
BOUNDEDNESS OF MAXIMAL SINGULAR INTEGRALS
CHEN JIECHENG; ZHU XIANGRONG
2005-01-01
The authors study the singular integrals under the Hormander condition and the measure not satisfying the doubling condition. At first, if the corresponding singular integral is bounded from L2 to itseff, it is proved that the maximal singu lar integral is bounded from L∞ to RBMO except that it is infinite μ-a.e. on Rd. A sufficient condition and a necessary condition such that the maximal singular integral is bounded from L2 to itself are also obtained. There is a small gap between the two conditions.
Berthon, P; Fellmann, N
2002-09-01
The maximal aerobic velocity concept developed since eighties is considered as either the minimal velocity which elicits the maximal aerobic consumption or as the "velocity associated to maximal oxygen consumption". Different methods for measuring maximal aerobic velocity on treadmill in laboratory conditions have been elaborated, but all these specific protocols measure V(amax) either during a maximal oxygen consumption test or with an association of such a test. An inaccurate method presents a certain number of problems in the subsequent use of the results, for example in the elaboration of training programs, in the study of repeatability or in the determination of individual limit time. This study analyzes 14 different methods to understand their interests and limits in view to propose a general methodology for measuring V(amax). In brief, the test should be progressive and maximal without any rest period and of 17 to 20 min total duration. It should begin with a five min warm-up at 60-70% of the maximal aerobic power of the subjects. The beginning of the trial should be fixed so that four or five steps have to be run. The duration of the steps should be three min with a 1% slope and an increasing speed of 1.5 km x h(-1) until complete exhaustion. The last steps could be reduced at two min for a 1 km x h(-1) increment. The maximal aerobic velocity is adjusted in relation to duration of the last step.
Secret-Sharing over Multiple-Antenna Channels with Transmit Correlation
Zorgui, Marwen
2015-01-07
We consider secret-key agreement with public discussion over Rayleigh fastfading channels with transmit correlation. The legitimate receiver and the eavesdropper are assumed to have perfect channel knowledge while the transmitter has only knowledge of the transmit correlation matrix. First, We derive the expression of the key capacity under the considered setup. Then, we show that the optimal transmit strategy achieving the key capacity consists in transmitting Gaussian signals along the eingenvectors of the channel covariance matrix. The powers allocated to each channel mode are determined as the solution of a numerical optimization problem that we derive. We also provide a waterfilling interpretation of the optimal power allocation. Finally, we develop a necessary and sufficient condition for beamforming to be optimal, i.e., transmitting along the strongest channel mode only is key capacity-achieving.
R.Valli
2010-07-01
Full Text Available Power management is one of the vital issue in wireless sensor networks, where the lifetime of the networkrelies on battery powered nodes. Transmitting at high power reduces the lifetime of both the nodes andthe network. One efficient way of power management is to control the power at which the nodes transmit.In this paper, a virtual multiple input multiple output wireless sensor network (VMIMO-WSNcommunication architecture is considered and the power control of sensor nodes based on the approachof game theory is formulated. The use of game theory has proliferated, with a broad range of applicationsin wireless sensor networking. Approaches from game theory can be used to optimize node level as wellas network wide performance. The game here is categorized as an incomplete information game, in whichthe nodes do not have complete information about the strategies taken by other nodes. For virtualmultiple input multiple output wireless sensor network architecture considered, the Nash equilibrium isused to decide the optimal power level at which a node needs to transmit, to maximize its utility. Outcomeshows that the game theoretic approach considered for VMIMO-WSN architecture achieves the bestutility, by consuming less power.
Sexually Transmitted Infections in Tehran
Maryam Afrakhteh
2008-09-01
Full Text Available Objective: Sexually transmitted infections (STIs remain a public health problem of major significance in most parts of the world. This study aimed to detect the most prevalent pathogens in patients with signs and symptoms of STI referring to a group of university clinics in Tehran.Materials and methods: In this cross-sectional study using randomized cluster sampling, 507 consecutive male and female patients presenting with signs and symptoms of STI referring to selected health care centers of Shahid Beheshti University were evaluated between May 2005 and May 2007. Diagnosis was made according to WHO criteria for signs and symptoms of STI in addition to microscopic study of genital discharges. Results: The most prevalent STI pathogens were Candida, Trichomona, Neisseria gonorrhoeae and Chlamydia with respective frequencies of 53.96%, 18.87%, 4.91% and 22.26% in women and 47.10%, 8.67%, 9.50% and 34.71% in men.Conclusion: Candida was detected in majority of cases. Chlamydia was the most prevalent STI in both sexes. Simple preventive care has crucial role in decreasing the frequency of STIs in society.
Recessively transmitted predominantly motor neuropathies.
Parman, Yeşim; Battaloğlu, Esra
2013-01-01
Recessively transmitted predominantly motor neuropathies are rare and show a severe phenotype. They are frequently observed in populations with a high rate of consanguineous marriages. At least 15 genes and six loci have been found to be associated with autosomal recessive CMT (AR-CMT) and X-linked CMT (AR-CMTX) and also distal hereditary motor neuronopathy (AR-dHMN). These disorders are genetically heterogeneous but the clinical phenotype is relatively homogeneous. Distal muscle weakness and atrophy predominating in the lower extremities, diminished or absent deep tendon reflexes, distal sensory loss, and pes cavus are the main clinical features of this disorder with occasional cranial nerve involvement. Although genetic diagnosis of some of subtypes of AR-CMT are now available, rapid advances in the molecular genetics and cell biology show a great complexity. Animal models for the most common subtypes of human AR-CMT disease provide clues for understanding the pathogenesis of CMT and also help to reveal possible treatment strategies of inherited neuropathies. This chapter highlights the clinical features and the recent genetic and biological findings in these disorders based on the current classification.
Zoonosis that is Transmitted Through Food
Tri Budhi Murdiati; Indrawati Sendow
2006-01-01
Zoonosis can be transmitted through a number of routes including food of animal products . Foodborne disease is a disease transmitted through food, while zoonosis is defined as a disease that can be transmitted from animal to man or vice versa . Then, if agent in foodborne disease is a zoonotic, it could be defined as foodborne zoonosis . The outbreaks of Bovine Spongioform Encephalopathy (BSE) followed by Avian influenza (AI) have caused increasing concern in the food safety of animal produc...
USACE AIS Transmit Technical Support Summary Report
2014-09-01
USACE AIS Transmit Technical Support Summary Report Distribution Statement A: Approved for public release; distribution is unlimited...September 2014 Report No. CD-D-09-15 USACE AIS Transmit Technical Support Summary Report ii UNCLAS//Public | CG-926 RDC | I. Gonin et al. Public...States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 USACE AIS Transmit Technical Support Summary Report
Understanding maximal repetitions in strings
Crochemore, Maxime
2008-01-01
The cornerstone of any algorithm computing all repetitions in a string of length n in O(n) time is the fact that the number of runs (or maximal repetitions) is O(n). We give a simple proof of this result. As a consequence of our approach, the stronger result concerning the linearity of the sum of exponents of all runs follows easily.
Transceiver Design to Maximize the Weighted Sum Secrecy Rate in Full-Duplex SWIPT Systems
Wang, Ying; Sun, Ruijin; Wang, Xinshui
2016-06-01
This letter considers secrecy simultaneous wireless information and power transfer (SWIPT) in full duplex systems. In such a system, full duplex capable base station (FD-BS) is designed to transmit data to one downlink user and concurrently receive data from one uplink user, while one idle user harvests the radio-frequency (RF) signals energy to extend its lifetime. Moreover, to prevent eavesdropping, artificial noise (AN) is exploited by FD-BS to degrade the channel of the idle user, as well as to provide energy supply to the idle user. To maximize the sum of downlink secrecy rate and uplink secrecy rate, we jointly optimize the information covariance matrix, AN covariance matrix and receiver vector, under the constraints of the sum transmission power of FD-BS and the minimum harvested energy of the idle user. Since the problem is non-convex, the log-exponential reformulation and sequential parametric convex approximation (SPCA) method are used. Extensive simulation results are provided and demonstrate that our proposed full duplex scheme extremely outperforms the half duplex scheme.
Cooperative Communications via Dual-Teleportation with Non-maximally Entanglement Measurements
毛云; 郭迎; 曾贵华
2012-01-01
We investigate a framework of the cooperative quantum teleportation （CQT） based on non-maximally entangled state basis （NB） measurements,instead of maximally entangled state basis （MB） measurements.It is implemented with two consecutive conventional （or direct） quantum telportations （DQT）,where unknown quantum states can be transmitted in a point-to-point fashion.The security is based on the quantum-mechanical impossibility of local unitary transformations between non-maximally entangled states.It shows that the CQT can enhance the successful transmissions by self-correcting the errors introduced in the dual-teleportations.
Power Allocation over Two Identical Gilbert-Elliott Channels
Tang, Junhua
2012-01-01
We study the problem of power allocation over two identical Gilbert-Elliot communication channels. Our goal is to maximize the expected discounted number of bits transmitted over an infinite time horizon. This is achieved by choosing among three possible strategies: (1) betting on channel 1 by allocating all the power to this channel, which results in high data rate if channel 1 happens to be in good state, and zero bits transmitted if channel 1 is in bad state (even if channel 2 is in good state) (2) betting on channel 2 by allocating all the power to the second channel, and (3) a balanced strategy whereby each channel is allocated half the total power, with the effect that each channel can transmit a low data rate if it is in good state. We assume that each channel's state is only revealed upon transmission of data on that channel. We model this problem as a partially observable Markov decision processes (MDP), and derive key threshold properties of the optimal policy. Further, we show that by formulating a...
Note on maximal distance separable codes
YANG Jian-sheng; WANG De-xiu; JIN Qing-fang
2009-01-01
In this paper, the maximal length of maximal distance separable(MDS)codes is studied, and a new upper bound formula of the maximal length of MDS codes is obtained. Especially, the exact values of the maximal length of MDS codes in some parameters are given.
Maximization, learning, and economic behavior.
Erev, Ido; Roth, Alvin E
2014-07-22
The rationality assumption that underlies mainstream economic theory has proved to be a useful approximation, despite the fact that systematic violations to its predictions can be found. That is, the assumption of rational behavior is useful in understanding the ways in which many successful economic institutions function, although it is also true that actual human behavior falls systematically short of perfect rationality. We consider a possible explanation of this apparent inconsistency, suggesting that mechanisms that rest on the rationality assumption are likely to be successful when they create an environment in which the behavior they try to facilitate leads to the best payoff for all agents on average, and most of the time. Review of basic learning research suggests that, under these conditions, people quickly learn to maximize expected return. This review also shows that there are many situations in which experience does not increase maximization. In many cases, experience leads people to underweight rare events. In addition, the current paper suggests that it is convenient to distinguish between two behavioral approaches to improve economic analyses. The first, and more conventional approach among behavioral economists and psychologists interested in judgment and decision making, highlights violations of the rational model and proposes descriptive models that capture these violations. The second approach studies human learning to clarify the conditions under which people quickly learn to maximize expected return. The current review highlights one set of conditions of this type and shows how the understanding of these conditions can facilitate market design.
Guo, Xudong; Ge, Bin; Wang, Wenxing
2013-08-01
In order to detect endoleaks after endovascular aneurysm repair (EVAR), we developed an implantable micro-device based on wireless power transmission to measure aortic aneurysm sac pressure. The implantable micro-device is composed of a miniature wireless pressure sensor, an energy transmitting coil, a data recorder and a data processing platform. Power transmission without interconnecting wires is performed by a transmitting coil and a receiving coil. The coupling efficiency of wireless power transmission depends on the coupling coefficient between the transmitting coil and the receiving coil. With theoretical analysis and experimental study, we optimized the geometry of the receiving coil to increase the coupling coefficient. In order to keep efficiency balance and satisfy the maximizing conditions, we designed a closed loop power transmission circuit, including a receiving voltage feedback module based on wireless communication. The closed loop improved the stability and reliability of transmission energy. The prototype of the micro-device has been developed and the experiment has been performed. The experiments showed that the micro-device was feasible and valid. For normal operation, the distance between the transmitting coil and the receiving coil is smaller than 8cm. Besides, the distance between the micro-device and the data recorder is within 50cm.
Wei Wang
2016-03-01
Full Text Available Overhead high voltage power line (HVPL online monitoring equipment is playing an increasingly important role in smart grids, but the power supply is an obstacle to such systems’ stable and safe operation, so in this work a hybrid wireless power supply system, integrated with inductive energy harvesting and wireless power transmitting, is proposed. The energy harvesting device extracts energy from the HVPL and transfers that from the power line to monitoring equipment on transmission towers by transmitting and receiving coils, which are in a magnetically coupled resonant configuration. In this paper, the optimization design of online energy harvesting devices is analyzed emphatically by taking both HVPL insulation distance and wireless power supply efficiency into account. It is found that essential parameters contributing to more extracted energy include large core inner radius, core radial thickness, core height and small core gap within the threshold constraints. In addition, there is an optimal secondary coil turn that can maximize extracted energy when other parameters remain fixed. A simple and flexible control strategy is then introduced to limit power fluctuations caused by current variations. The optimization methods are finally verified experimentally.
A Multiuser MIMO Transmit Beamformer Based on the Statistics of the Signal-to-Leakage Ratio
Chalise BatuK
2009-01-01
Full Text Available A multiuser multiple-input multiple-output (MIMO downlink communication system is analyzed in a Rayleigh fading environment. The approximate closed-form expressions for the probability density function (PDF of the signal-to-leakage ratio (SLR, its average, and the outage probability have been derived in terms of the transmit beamformer weight vector. With the help of some conservative derivations, it has been shown that the transmit beamformer which maximizes the average SLR also minimizes the outage probability of the SLR. Computer simulations are carried out to compare the theoretical and simulation results for the channels whose spatial correlations are modeled with different methods.
YUAN Ting-ting; ZHANG Lei; YANG Hong-wen; YANG Da-cheng
2008-01-01
Downlinks of the cellular systems generally havemore transmit antennas than receive antennas. To efficientlyexploit all antenna resources, a technique that combines theadvantage of beamforming and spatial multiplexing has beenproposed, which partitions the transmit antennas into neigh-boring sub-groups. In this article, this technique is furtherimproved by Eq. (1) allowing non-contiguous antenna grouping,and Eq. (2) adopting two new grouping criteria: minimumsignal distance maximization(MSDM) criterion and maximumcorrelation coefficient minimization (MCCM) criterion. Simulationresults indicate that these improvements can bring noticeablegains in the Rayleigh flat fading channel environment.
POWER ALLOCATION OF DATA DEPENDENT SUPERIMPOSED TRAINING
Wang Ping; Yuan Weina; Fan Pingzhi
2008-01-01
Data Dependent Superimposed Training (DDST) scheme outperforms the traditional superimposed training by fully canceling the effects of unknown data in channel estimator. In DDST,however,the channel estimation accuracy and the data detection or channel equalization performance are affected significantly by the amount of power allocated to data and superimposed training sequence,which is the motivation of this research. In general,for DDST,there is a tradeoff between the channel estimation accuracy and the data detection reliability,i.e.,the more accurate the channel estimation,the more reliable the data detection; on the other hand,the more accurate the channel estimation,the more demanding on the power consumption of training sequence,which in turn leads to the less reliable data detection. In this paper,the relationship between the Signal-to-Noise Ratio (SNR) of the data detector and the training sequence power is analyzed. The optimal power allocation of the training sequence is derived based on the criterion of maximizing SNR of the detector. Analysis and simulation results show that for a fixed transmit power,the SNR and the Symbol Error Rate (SER) of detector vary nonlinearly with the increasing of training sequence power,and there exists an optimal power ratio,which accords with the derived optimal power ratio,among the data and training sequence.
Applications of expectation maximization algorithm for coherent optical communication
Carvalho, L.; Oliveira, J.; Zibar, Darko
2014-01-01
In this invited paper, we present powerful statistical signal processing methods, used by machine learning community, and link them to current problems in optical communication. In particular, we will look into iterative maximum likelihood parameter estimation based on expectation maximization al...
The influence of body position on maximal performance in cycling.
Welbergen, E; Clijsen, L P
1990-01-01
Six healthy male subjects performed a 3-min supramaximal test in four different cycling positions: two with different trunk angles and two with different saddle-tube angles. Maximal power output and maximal oxygen uptake (VO2max) were measured. Maximal power output was significantly higher in a standard sitting (SS, 381 W, SD 49) upright position compared to all other positions: standard racing (SR, 364 W, SD 49), recumbent backwards (RB, 355 W, SD 44) and recumbent forwards (RF, 341 W, SD 54). Although VO2max was also highest in SS (4.31 l.min-1, SD 0.5) upright position, the differences in VO2max were not significant (SR, 4.2 l.min-1, SD 0.53; RB, 4.17 l.min-1, SD 0.58; RF, 4.11 l.min-1, SD 0.66). It is concluded that (supra)maximal tests on a cycle ergometer should be performed in a sitting upright position and not in a racing position. In some cases when cycling on the road, higher speeds can be attained when sitting upright. This is especially true when cycling uphill when high power must be generated to overcome gravity but the road speed, and hence the power required to overcome air resistance, is relatively low.
Hee-Nam Cho
2010-01-01
Full Text Available This paper considers coordinated transmission for interference mitigation and power allocation in a correlated two-user two-hop multi-input multioutput (MIMO relay system. The proposed transmission scheme utilizes statistical channel state information (CSI (e.g., transmit correlation to minimize the cochannel interference (CCI caused by the relay. To this end, it is shown that the CCI can be represented in terms of the eigenvalues and the angle difference between the eigenvectors of the transmit correlation matrix of the intended and CCI channel, and that the condition minimizing the CCI can be characterized by the correlation amplitude and the phase difference between the transmit correlation coefficients of these channels. Then, a coordinated user-scheduling strategy is designed with the use of eigen-beamforming to minimize the CCI in an average sense. The transmit power of the base station and relay is optimized under separate power constraint. Analytic and numerical results show that the proposed scheme can maximize the achievable sum rate when the principal eigenvectors of the transmit correlation matrix of the intended and the CCI channel are orthogonal to each other, yielding a sum rate performance comparable to that of the minimum mean-square error-based coordinated beamforming which uses instantaneous CSI.
PAPR Reduction in OFDM Using Partial Transmit Sequence (PTS
R.Gayathri
2013-04-01
Full Text Available In recent years, OFDM has gained a lot of interest in diverse-digital communication applications. This has been due to its favorable properties like high spectral efficiency and robustness to channel fading. Some of the major drawbacks in OFDM are its high peak-to-average-power ratio(PAPR of the transmitted signals and the synchronization of signals. OFDM consist of large number of independent subcarriers, as a result of which the amplitude of such a signal can have high peak values. Coding, phase rotation and clipping are among many PAPR reduction schemes that have been proposed to overcome this problem. Significant reduction in PAPR has been achieved using Partial Transmit Sequence(PTS which comes under Signal scrambling techniques.
Parasitic diseases in humans transmitted by vectors.
Cholewiński, Marcin; Derda, Monika; Hadaś, Edward
2015-01-01
Despite the considerable progress of medicine, parasitic diseases still pose a great threat to human health and life. Among parasitic diseases, those transmitted by vectors, mainly arthropods, play a particular role. These diseases occur most frequently in the poorest countries and affect a vast part of the human population. They include malaria, babesiosis, trypanosomiasis, leishmaniasis and filariasis. This study presents those vector-transmitted diseases that are responsible for the greatest incidence and mortality of people on a global scale. Attention is focused primarily on diseases transmitted by mosquitoes, flies, Hemiptera and ticks.
Multivariate residues and maximal unitarity
Søgaard, Mads; Zhang, Yang
2013-12-01
We extend the maximal unitarity method to amplitude contributions whose cuts define multidimensional algebraic varieties. The technique is valid to all orders and is explicitly demonstrated at three loops in gauge theories with any number of fermions and scalars in the adjoint representation. Deca-cuts realized by replacement of real slice integration contours by higher-dimensional tori encircling the global poles are used to factorize the planar triple box onto a product of trees. We apply computational algebraic geometry and multivariate complex analysis to derive unique projectors for all master integral coefficients and obtain compact analytic formulae in terms of tree-level data.
Beeping a Maximal Independent Set
Afek, Yehuda; Alon, Noga; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian
2012-01-01
We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot...
Maximal Congruences on Some Semigroups
Jintana Sanwong; R.P. Sullivan
2007-01-01
In 1976 Howie proved that a finite congruence-free semigroup is a simple group if it has at least three elements but no zero elementInfinite congruence-free semigroups are far more complicated to describe, but some have been constructed using semigroups of transformations (for example, by Howie in 1981 and by Marques in 1983)Here, forcertain semigroups S of numbers and of transformations, we determine all congruences p on S such that S/p is congruence-free, that is, we describe all maximal congruences on such semigroups S.
Shi, Shengchao; Li, Guangxia; An, Kang; Gao, Bin; Zheng, Gan
2017-09-04
This paper proposes novel satellite-based wireless sensor networks (WSNs), which integrate the WSN with the cognitive satellite terrestrial network. Having the ability to provide seamless network access and alleviate the spectrum scarcity, cognitive satellite terrestrial networks are considered as a promising candidate for future wireless networks with emerging requirements of ubiquitous broadband applications and increasing demand for spectral resources. With the emerging environmental and energy cost concerns in communication systems, explicit concerns on energy efficient resource allocation in satellite networks have also recently received considerable attention. In this regard, this paper proposes energy-efficient optimal power allocation schemes in the cognitive satellite terrestrial networks for non-real-time and real-time applications, respectively, which maximize the energy efficiency (EE) of the cognitive satellite user while guaranteeing the interference at the primary terrestrial user below an acceptable level. Specifically, average interference power (AIP) constraint is employed to protect the communication quality of the primary terrestrial user while average transmit power (ATP) or peak transmit power (PTP) constraint is adopted to regulate the transmit power of the satellite user. Since the energy-efficient power allocation optimization problem belongs to the nonlinear concave fractional programming problem, we solve it by combining Dinkelbach's method with Lagrange duality method. Simulation results demonstrate that the fading severity of the terrestrial interference link is favorable to the satellite user who can achieve EE gain under the ATP constraint comparing to the PTP constraint.
Evolution of Shanghai STOCK Market Based on Maximal Spanning Trees
Yang, Chunxia; Shen, Ying; Xia, Bingying
2013-01-01
In this paper, using a moving window to scan through every stock price time series over a period from 2 January 2001 to 11 March 2011 and mutual information to measure the statistical interdependence between stock prices, we construct a corresponding weighted network for 501 Shanghai stocks in every given window. Next, we extract its maximal spanning tree and understand the structure variation of Shanghai stock market by analyzing the average path length, the influence of the center node and the p-value for every maximal spanning tree. A further analysis of the structure properties of maximal spanning trees over different periods of Shanghai stock market is carried out. All the obtained results indicate that the periods around 8 August 2005, 17 October 2007 and 25 December 2008 are turning points of Shanghai stock market, at turning points, the topology structure of the maximal spanning tree changes obviously: the degree of separation between nodes increases; the structure becomes looser; the influence of the center node gets smaller, and the degree distribution of the maximal spanning tree is no longer a power-law distribution. Lastly, we give an analysis of the variations of the single-step and multi-step survival ratios for all maximal spanning trees and find that two stocks are closely bonded and hard to be broken in a short term, on the contrary, no pair of stocks remains closely bonded for a long time.
Knowledge discovery by accuracy maximization.
Cacciatore, Stefano; Luchinat, Claudio; Tenori, Leonardo
2014-04-01
Here we describe KODAMA (knowledge discovery by accuracy maximization), an unsupervised and semisupervised learning algorithm that performs feature extraction from noisy and high-dimensional data. Unlike other data mining methods, the peculiarity of KODAMA is that it is driven by an integrated procedure of cross-validation of the results. The discovery of a local manifold's topology is led by a classifier through a Monte Carlo procedure of maximization of cross-validated predictive accuracy. Briefly, our approach differs from previous methods in that it has an integrated procedure of validation of the results. In this way, the method ensures the highest robustness of the obtained solution. This robustness is demonstrated on experimental datasets of gene expression and metabolomics, where KODAMA compares favorably with other existing feature extraction methods. KODAMA is then applied to an astronomical dataset, revealing unexpected features. Interesting and not easily predictable features are also found in the analysis of the State of the Union speeches by American presidents: KODAMA reveals an abrupt linguistic transition sharply separating all post-Reagan from all pre-Reagan speeches. The transition occurs during Reagan's presidency and not from its beginning.
Inapproximability of maximal strip recovery
Jiang, Minghui
2009-01-01
In comparative genomic, the first step of sequence analysis is usually to decompose two or more genomes into syntenic blocks that are segments of homologous chromosomes. For the reliable recovery of syntenic blocks, noise and ambiguities in the genomic maps need to be removed first. Maximal Strip Recovery (MSR) is an optimization problem proposed by Zheng, Zhu, and Sankoff for reliably recovering syntenic blocks from genomic maps in the midst of noise and ambiguities. Given $d$ genomic maps as sequences of gene markers, the objective of \\msr{d} is to find $d$ subsequences, one subsequence of each genomic map, such that the total length of syntenic blocks in these subsequences is maximized. For any constant $d \\ge 2$, a polynomial-time 2d-approximation for \\msr{d} was previously known. In this paper, we show that for any $d \\ge 2$, \\msr{d} is APX-hard, even for the most basic version of the problem in which all gene markers are distinct and appear in positive orientation in each genomic map. Moreover, we provi...
Maximal right smooth extension chains
Huang, Yun Bao
2010-01-01
If $w=u\\alpha$ for $\\alpha\\in \\Sigma=\\{1,2\\}$ and $u\\in \\Sigma^*$, then $w$ is said to be a \\textit{simple right extension}of $u$ and denoted by $u\\prec w$. Let $k$ be a positive integer and $P^k(\\epsilon)$ denote the set of all $C^\\infty$-words of height $k$. Set $u_{1},\\,u_{2},..., u_{m}\\in P^{k}(\\epsilon)$, if $u_{1}\\prec u_{2}\\prec ...\\prec u_{m}$ and there is no element $v$ of $P^{k}(\\epsilon)$ such that $v\\prec u_{1}\\text{or} u_{m}\\prec v$, then $u_{1}\\prec u_{2}\\prec...\\prec u_{m}$ is said to be a \\textit{maximal right smooth extension (MRSE) chains}of height $k$. In this paper, we show that \\textit{MRSE} chains of height $k$ constitutes a partition of smooth words of height $k$ and give the formula of the number of \\textit{MRSE} chains of height $k$ for each positive integer $k$. Moreover, since there exist the minimal height $h_1$ and maximal height $h_2$ of smooth words of length $n$ for each positive integer $n$, we find that \\textit{MRSE} chains of heights $h_1-1$ and $h_2+1$ are good candidates t...
Link Scheduling in Multi-Transmit-Receive Wireless Networks
Dai, Hong-Ning; Fu, Liqun
2011-01-01
This paper investigates the problem of link scheduling to meet traffic demands with minimum airtime in a multi-transmit-receive (MTR) wireless network. MTR networks are a new class of networks, in which each node can simultaneously transmit to a number of other nodes, or simultaneously receive from a number of other nodes. The MTR capability can be enabled by the use of multiple directional antennas or multiple channels. Potentially, MTR can boost the network capacity significantly. However, link scheduling that makes full use of the MTR capability must be in place before this can happen. We show that optimal link scheduling can be formulated as a linear program (LP). However, the problem is NP-hard because we need to find all the maximal independent sets in a graph first. We propose two computationally efficient algorithms, called Heavy-Weight-First (HWF) and Max-Degree-First (MDF) to solve this problem. Simulation results show that both HWF and MDF can achieve superior performance in terms of runtime and op...
Rasoulnia, P; Mousavi, S M
2016-09-01
Spent-medium bioleaching of V and Ni from a power plant residual ash (PPR ash) was conducted using organic acids produced by Aspergillus niger. The production of organic acids in a bubble column bioreactor was optimized through selecting three most influencing factors. Under optimum condition of aeration rate of 762.5(ml/min), sucrose concentration of 101.9(g/l) and inoculum size of 40(ml/l), respectively 17,185, 4539, 1042 and 502(ppm) of oxalic, gluconic, citric and malic acids were produced. Leaching experiments were carried out using biogenic produced organic acids under leaching environment temperature of 60°C and rotary shaking speed of 135rpm, with various pulp densities of 1, 2, 3, 5, 7 and 9(%w/v). The results showed that biogenic produced organic acids leached V much more efficiently than Ni so that even at high pulp density of 9(%w/v), 83% of V was recovered while Ni recovery yield was 30%.
CDC WONDER: Sexually Transmitted Disease (STD) Morbidity
U.S. Department of Health & Human Services — The Sexually Transmitted Disease (STD) Morbidity online databases on CDC WONDER contain case reports reported from the 50 United States and D.C., Puerto Rico, Virgin...
CDC WONDER: Sexually Transmitted Disease (STD) morbidity
U.S. Department of Health & Human Services — The Sexually Transmitted Disease (STD) Morbidity online databases on CDC WONDER contain case reports reported from the 50 United States and D.C., Puerto Rico, Virgin...
syndromic management of sexually transmitted infections
Kurt
infectious disease service delivery. He has led ... referred to as classic sexually transmitted infections (STIs). ... chomoniasis) occur every year in developing countries.2 In South ... motion of STI prevention is often absent (most patients did not.
Clinical update in sexually transmitted diseases-2014.
Fanfair, Robyn Neblett; Workowski, Kimberly A
2014-02-01
Sexually transmitted diseases (STDs) and their associated syndromes are extremely common in clinical practice. Early diagnosis, appropriate treatment, and partner management are important to ensure sexual, physical, and reproductive health in our patients.
Sexually Transmitted Diseases: Teens at Risk.
Mascola, Laurene
1987-01-01
Parents of preteens need to be aware of the rapidly increasing incidence of sexually transmitted diseases among teenagers and to begin talking to their preteens to help prevent or modify risky sexual experimentation during middle adolescence. (MT)
Transmitting boundary and radiation conditions at infinity
廖振鹏
2001-01-01
Relationship between the radiation conditions at infinity and the transmitting boundary for numerical simulation of the near-field wave motion has been studied in this paper. The conclusion is that the transmitting boundary is approximately equivalent to the radiation conditions at infinity for a large class of infinite media. And the errors of the approximation are of the same order of magnitude as those of the finite elements or finite differences in numerical simulation of wave motion. This result provides a sound theoretical basis for the transmitting boundary used in the numerical simulation of the near-field wave motion and gives a complete explanation for the major experiences accumulated in applications of the transmitting boundary to the numerical simulation.
Vulnerability and Knowledge of Sexually Transmitted Infections ...
hanumantp
common causes of illness world-wide with far reaching health, ... Keywords: Enugu, Female traders, Knowledge, Prevention, Sexually transmitted infections, Vulnerability. Original ... constituted the work force, especially in developing countries.
Knowledge of Sexually Transmitted Diseases among Secondary ...
KeyWords: Sexually transmitted diseases, Adolescent, Knowledge, Information, ... AIDS is relatively low when compared to other locations in the country. ... be as a result of inadequate diagnostic and treatment facilities in the rural areas fear of.
Tackling sexually transmitted infection burden in Ugandan ...
Background: Despite being in a different country and social environment, Ugandans living in ... Keywords:sexually transmitted infection, Ugandan communities, .... their prevention to enable control programs take root. Methods. This study used ...
Knowledge of sexually transmitted diseases among secondary ...
Knowledge of sexually transmitted diseases among secondary school students in ... prevent the diseases among adolescent populations in developing countries. ... simple random sampling and stratified sampling methods was used to select ...
Pure germanium dioxide hollow-core fiber for transmitting CO2 laser
侯兰田; 付连符; 吕平; 韩玉华; 李秋更; 徐立宣; 李天柱
1995-01-01
A method of fabricating pure germanium dioxide hollow-core fibers has been introduced for the first time. The output power of the fabricated fiber can come to 18 W, with the transmission loss of 1.23 dB/m at 10.6 μm. The mechanism of transmitting CO2 laser by the fiber is analyzed, the transmitting loss is further discussed and its application fields are envisaged.
Adaptive maximal poisson-disk sampling on surfaces
Yan, Dongming
2012-01-01
In this paper, we study the generation of maximal Poisson-disk sets with varying radii on surfaces. Based on the concepts of power diagram and regular triangulation, we present a geometric analysis of gaps in such disk sets on surfaces, which is the key ingredient of the adaptive maximal Poisson-disk sampling framework. Moreover, we adapt the presented sampling framework for remeshing applications. Several novel and efficient operators are developed for improving the sampling/meshing quality over the state-of-theart. © 2012 ACM.
Gap processing for adaptive maximal Poisson-disk sampling
Yan, Dongming
2013-09-01
In this article, we study the generation of maximal Poisson-disk sets with varying radii. First, we present a geometric analysis of gaps in such disk sets. This analysis is the basis for maximal and adaptive sampling in Euclidean space and on manifolds. Second, we propose efficient algorithms and data structures to detect gaps and update gaps when disks are inserted, deleted, moved, or when their radii are changed.We build on the concepts of regular triangulations and the power diagram. Third, we show how our analysis contributes to the state-of-the-art in surface remeshing. © 2013 ACM.
PERFORMANCE OF CLOSED LOOP TRANSMIT DIVERSITY IN A RAYLEIGH FADING CHANNEL
Yang Xin; You Xiaohu
2006-01-01
In this paper, the closed loop transmit diversity technology for the Wideband Code Division Multiple Access(WCDMA) systems is investigated in a multipath Rayleigh fading channel. The RAKE receiver model and the weighing vector algorithm are presented. The performance is theoretically analyzed in terms of the average maximal Signal-to-Noise Ratio(SNR) gain available over the Space-Time block coding based Transmit Diversity(STTD) technology. Theoretic analysis and simulation results show that the closed loop transmit diversity can provide a 3dB performance gain over the open loop scheme in a single path fading channel, while the performance gain decreases dramatically with the increasing inherent multipath diversity of the wireless channel.
Estimating Transmitted-Signal Phase Variations for Uplink Array Antennas
Paal, Leslie; Mukai, Ryan; Vilntrotter, Victor; Cornish, Timothy; Lee, Dennis
2009-01-01
-processing center, then distributed to the antennas via optical fibers. At each antenna, the signals are used to drive a microwave power-amplifier train, the output of which is coupled to the antenna for transmission. A small fraction of the power-amplifier-train output is sent back to the signal-processing center along another optical fiber that is part of the same fiber-optic cable used to distribute the transmitted signal to the antenna. In the signal-processing center, the signal thus returned from each antenna is detected and its phase is compared with the phase of the signal sampled directly from the corresponding exciter. It is known, from other measurements, that the signal-propagation path length from the power-amplifier-train output port to the phase center of each antenna is sufficiently stable and, hence, that sampling the signal at the power-amplifier-train output port suffices for the purpose of characterizing the phase drift of the transmitted signal at the phase center of the antenna
The maximal D = 4 supergravities
Wit, Bernard de [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, Postbus 80.195, NL-3508 TD Utrecht (Netherlands); Samtleben, Henning [Laboratoire de Physique, ENS Lyon, 46 allee d' Italie, F-69364 Lyon CEDEX 07 (France); Trigiante, Mario [Dept. of Physics, Politecnico di Torino, Corso Duca degli Abruzzi 24, I-10129 Turin (Italy)
2007-06-15
All maximal supergravities in four space-time dimensions are presented. The ungauged Lagrangians can be encoded in an E{sub 7(7)}-Sp(56; R)/GL(28) matrix associated with the freedom of performing electric/magnetic duality transformations. The gauging is defined in terms of an embedding tensor {theta} which encodes the subgroup of E{sub 7(7)} that is realized as a local invariance. This embedding tensor may imply the presence of magnetic charges which require corresponding dual gauge fields. The latter can be incorporated by using a recently proposed formulation that involves tensor gauge fields in the adjoint representation of E{sub 7(7)}. In this formulation the results take a universal form irrespective of the electric/magnetic duality basis. We present the general class of supersymmetric and gauge invariant Lagrangians and discuss a number of applications.
Maximizing profit using recommender systems
Das, Aparna; Ricketts, Daniel
2009-01-01
Traditional recommendation systems make recommendations based solely on the customer's past purchases, product ratings and demographic data without considering the profitability the items being recommended. In this work we study the question of how a vendor can directly incorporate the profitability of items into its recommender so as to maximize its expected profit while still providing accurate recommendations. Our approach uses the output of any traditional recommender system and adjust them according to item profitabilities. Our approach is parameterized so the vendor can control how much the recommendation incorporating profits can deviate from the traditional recommendation. We study our approach under two settings and show that it achieves approximately 22% more profit than traditional recommendations.
The maximal D=5 supergravities
de Wit, Bernard; Trigiante, M; Wit, Bernard de; Samtleben, Henning; Trigiante, Mario
2007-01-01
The general Lagrangian for maximal supergravity in five spacetime dimensions is presented with vector potentials in the \\bar{27} and tensor fields in the 27 representation of E_6. This novel tensor-vector system is subject to an intricate set of gauge transformations, describing 3(27-t) massless helicity degrees of freedom for the vector fields and 3t massive spin degrees of freedom for the tensor fields, where the (even) value of t depends on the gauging. The kinetic term of the tensor fields is accompanied by a unique Chern-Simons coupling which involves both vector and tensor fields. The Lagrangians are completely encoded in terms of the embedding tensor which defines the E_6 subgroup that is gauged by the vectors. The embedding tensor is subject to two constraints which ensure the consistency of the combined vector-tensor gauge transformations and the supersymmetry of the full Lagrangian. This new formulation encompasses all possible gaugings.
Constraint Propagation as Information Maximization
Abdallah, A Nait
2012-01-01
Dana Scott used the partial order among partial functions for his mathematical model of recursively defined functions. He interpreted the partial order as one of information content. In this paper we elaborate on Scott's suggestion of regarding computation as a process of information maximization by applying it to the solution of constraint satisfaction problems. Here the method of constraint propagation can be interpreted as decreasing uncertainty about the solution -- that is, as gain in information about the solution. As illustrative example we choose numerical constraint satisfaction problems to be solved by interval constraints. To facilitate this approach to constraint solving we formulate constraint satisfaction problems as formulas in predicate logic. This necessitates extending the usual semantics for predicate logic so that meaning is assigned not only to sentences but also to formulas with free variables.
Liu, Hongpeng; Yang, Yongheng; Loh, Poh Chiang
2016-01-01
In this paper, a novel communication strategy called Power Talk is introduced to realize the power line communication among the Voltage Source Converters (VSC) of DC MicroGrids (MGs). Each VSC transmits information by changing the control parameters, and receives information by observing the local...... output power. By using common coding schemes, which transform the DC MGs in some familiar communication channels, some important communication challenges can be addressed, such as random load variations and VSCs switching, as it do not need a separate communication channel. For this purpose, two multiple...
Imperfect generalized transmit beamforming with co-channel interference cancelation
Radaydeh, Redha Mahmoud Mesleh
2010-10-01
The performance of a generalized single-stream transmit beamforming scheme employing receive co-channel interference -steering algorithms in slowly varying and flat fading channels is analyzed. The impact of imperfect prediction of channel state information (CSI) for the desired user spatially uncorrelated transmit channels is considered. Both dominant interference cancelation and adaptive arbitrary interference cancelation algorithms for closely spaced receive antennas are used. The impact of outdated statistical ordering of the interferers instantaneous powers on the effectiveness of dominant interference cancelation is investigated against the less complex adaptive arbitrary cancelation scheme. For the system models described above, new exact formulas for the statistics of combined signal-to-interference-plus-noise ratio (SINR) are derived, from which results for conventional maximum ratio transmission (MRT) and best transmit channel selection schemes can be deduced as limiting cases. The results presented herein can be used to obtain quantitative measure for various performance metrics, and in addition to investigate the performance-complexity tradeoff for different multiple-antenna system models. © 2010 IEEE.
MIMO Radar Transmit Beampattern Design Without Synthesising the Covariance Matrix
Ahmed, Sajid
2013-10-28
Compared to phased-array, multiple-input multiple-output (MIMO) radars provide more degrees-offreedom (DOF) that can be exploited for improved spatial resolution, better parametric identifiability, lower side-lobe levels at the transmitter/receiver, and design variety of transmit beampatterns. The design of the transmit beampattern generally requires the waveforms to have arbitrary auto- and crosscorrelation properties. The generation of such waveforms is a two step complicated process. In the first step a waveform covariance matrix is synthesised, which is a constrained optimisation problem. In the second step, to realise this covariance matrix actual waveforms are designed, which is also a constrained optimisation problem. Our proposed scheme converts this two step constrained optimisation problem into a one step unconstrained optimisation problem. In the proposed scheme, in contrast to synthesising the covariance matrix for the desired beampattern, nT independent finite-alphabet constantenvelope waveforms are generated and pre-processed, with weight matrix W, before transmitting from the antennas. In this work, two weight matrices are proposed that can be easily optimised for the desired symmetric and non-symmetric beampatterns and guarantee equal average power transmission from each antenna. Simulation results validate our claims.
Sexually transmitted diseases: reflections on metaphors and ethics.
Badura-Lotter, Gisela
2012-01-01
Sexually transmitted diseases (STDs) are probably the most tabooed diseases we know. The taboos and the related stigmata shape patients reality and influence significantly health care policies, medical research, and actual problems in medical ethics. To better understand these complex influences of ancient but still powerful taboos, related metaphors associated with illness and disease are analyzed according to their historical development and actual impact on society. It becomes obvious that research and health care policies cannot be satisfyingly successful in helping people affected by STDs as long as they do not take the mechanisms of taboos and associated metaphors into account.
Sun, Fan; De Carvalho, Elisabeth
2012-01-01
This paper proposes a low-complexity design for the linear weighted MMSE (WMMSE) transmit filters of a coordinated multi-cell system with multiple users per cell. This design is based on a modified WMMSE approach applied to each transmitting base station individually incorporating the signals sent...... the linear transmit filter maximizing the weighted sum-rate of the multicell system. This algorithm is based on WMMSE where the MSE weights are optimally adjusted so that the WMMSE optimum coincides with the WSR optimum....
Perceptions of sexually transmitted diseases among teenagers
DM Diale
2000-09-01
Full Text Available An ex p lo ra to ry d e sc rip tiv e study was u n d e rtak en , focussing on sexually transmitted diseases (STD among teenagers. The aim of the study was to explore and describe the possible reasons for the high rate of sexually transmitted diseases in teenagers. The perceptions of teenagers and community nurses regarding sexually transmitted disease among teenagers involved in the teenage clinic in a specific predominantly black area were assessed. Twenty teenagers and five community nurses were participants in the study. Two focus group interviews were conducted with teenagers and community nurses. It can be concluded that the attitudes of community nurses may have an influence on the high rate of sexually transmitted diseases among teenagers. The knowledge o f the teenagers about sexually transmitted diseases is often based on myths and misconceptions which could be intensified by the community nurse. The recommendations made are that the education standards of all community nurses should be reviewed and adapted to meet the needs of teenagers attending the teenage health services. The policy on in-service training must be reviewed and monitored. Community nurses’ intensive training on teenage health service delivery and sexually transmitted diseases services should be in accordance with the principles of Primary Health Care. Community nurses need to attend intensive courses on interpersonal skills specifically related to teenagers. Selection procedures for recruiting community nurses to attend to teenagers specifically should be researched. Teenagers should be involved in planning programs and the teenage clinic should be evaluated frequently to improve the standards. The availability of adequate teenage health services can result in a decrease in sexually transmitted diseases among teenagers.
Energy, complexity and wealth maximization
Ayres, Robert
2016-01-01
This book is about the mechanisms of wealth creation, or what we like to think of as evolutionary “progress”. For the modern economy, natural wealth consists of complex physical structures of condensed (“frozen”) energy – mass - maintained in the earth’s crust far from thermodynamic equilibrium. However, we usually perceive wealth as created when mutation or “invention” – a change agent - introduces something different, and fitter, and usually after some part of the natural wealth of the planet has been exploited in an episode of “creative destruction”. Selection out of the resulting diversity is determined by survival in a competitive environment, whether a planet, a habitat, or a market. While human wealth is associated with money and what it can buy, it is ultimately based on natural wealth, both as materials transformed into useful artifacts, and how those artifacts, activated by energy, can create and transmit useful information. Humans have learned how to transform natural wealth i...
Optimal Time Allocation in Backscatter Assisted Wireless Powered Communication Networks
Lyu, Bin; Yang, Zhen; Gui, Guan; Sari, Hikmet
2017-01-01
This paper proposes a wireless powered communication network (WPCN) assisted by backscatter communication (BackCom). This model consists of a power station, an information receiver and multiple users that can work in either BackCom mode or harvest-then-transmit (HTT) mode. The time block is mainly divided into two parts corresponding to the data backscattering and transmission periods, respectively. The users first backscatter data to the information receiver in time division multiple access (TDMA) during the data backscattering period. When one user works in the BackCom mode, the other users harvest energy from the power station. During the data transmission period, two schemes, i.e., non-orthogonal multiple access (NOMA) and TDMA, are considered. To maximize the system throughput, the optimal time allocation policies are obtained. Simulation results demonstrate the superiority of the proposed model. PMID:28587171
QoS awared power and admission controls based on non-cooperative game theory in wireless networks
2008-01-01
In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QeS-aware power and admission controls (QAPAC) is proposed. The system is modeled as u non- cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS reqniremcnts and improve system capacity compared with those that ignore the QoS differ- ences.
QoS awared power and admission controls based on non-cooperative game theory in wireless networks
无
2008-01-01
In order to better accommodate heterogeneous quality of service (QoS) in wireless networks, an algorithm called QoS-aware power and admission controls (QAPAC) is proposed. The system is modeled as a non-cooperative game where the users adjust their transmit powers to maximize the utility, thus restraining the interferences. By using adaptive utility functions and tunable pricing parameters according to QoS levels, this algorithm can well meet different QoS requirements and improve system capacity compared w...
Long-Term Energy Constraints and Power Control in Cognitive Radio Networks
Mériaux, François; Lasaulce, Samson; Garnaev, Andrey
2011-01-01
When a long-term energy constraint is imposed to a transmitter, the average energy-efficiency of a transmitter is, in general, not maximized by always transmitting. In a cognitive radio context, this means that a secondary link can re-exploit the non-used time-slots. In the case where the secondary link is imposed to generate no interference on the primary link, a relevant issue is therefore to know the fraction of time-slots available to the secondary transmitter, depending on the system parameters. On the other hand, if the secondary transmitter is modeled as a selfish and free player choosing its power control policy to maximize its average energy-efficiency, resulting primary and secondary signals are not necessarily orthogonal and studying the corresponding Stackelberg game is relevant to know the outcome of this interactive situation in terms of power control policies.
Beeping a Maximal Independent Set
Afek, Yehuda; Bar-Joseph, Ziv; Cornejo, Alejandro; Haeupler, Bernhard; Kuhn, Fabian
2012-01-01
We consider the problem of computing a maximal independent set (MIS) in an extremely harsh broadcast model that relies only on carrier sensing. The model consists of an anonymous broadcast network in which nodes have no knowledge about the topology of the network or even an upper bound on its size. Furthermore, it is assumed that an adversary chooses at which time slot each node wakes up. At each time slot a node can either beep, that is, emit a signal, or be silent. At a particular time slot, beeping nodes receive no feedback, while silent nodes can only differentiate between none of its neighbors beeping, or at least one of its neighbors beeping. We start by proving a lower bound that shows that in this model, it is not possible to locally converge to an MIS in sub-polynomial time. We then study four different relaxations of the model which allow us to circumvent the lower bound and find an MIS in polylogarithmic time. First, we show that if a polynomial upper bound on the network size is known, it is possi...
Maximal switchability of centralized networks
Vakulenko, Sergei; Morozov, Ivan; Radulescu, Ovidiu
2016-08-01
We consider continuous time Hopfield-like recurrent networks as dynamical models for gene regulation and neural networks. We are interested in networks that contain n high-degree nodes preferably connected to a large number of N s weakly connected satellites, a property that we call n/N s -centrality. If the hub dynamics is slow, we obtain that the large time network dynamics is completely defined by the hub dynamics. Moreover, such networks are maximally flexible and switchable, in the sense that they can switch from a globally attractive rest state to any structurally stable dynamics when the response time of a special controller hub is changed. In particular, we show that a decrease of the controller hub response time can lead to a sharp variation in the network attractor structure: we can obtain a set of new local attractors, whose number can increase exponentially with N, the total number of nodes of the nework. These new attractors can be periodic or even chaotic. We provide an algorithm, which allows us to design networks with the desired switching properties, or to learn them from time series, by adjusting the interactions between hubs and satellites. Such switchable networks could be used as models for context dependent adaptation in functional genetics or as models for cognitive functions in neuroscience.
A Maximally Supersymmetric Kondo Model
Harrison, Sarah; Kachru, Shamit; Torroba, Gonzalo; /Stanford U., Phys. Dept. /SLAC
2012-02-17
We study the maximally supersymmetric Kondo model obtained by adding a fermionic impurity to N = 4 supersymmetric Yang-Mills theory. While the original Kondo problem describes a defect interacting with a free Fermi liquid of itinerant electrons, here the ambient theory is an interacting CFT, and this introduces qualitatively new features into the system. The model arises in string theory by considering the intersection of a stack of M D5-branes with a stack of N D3-branes, at a point in the D3 worldvolume. We analyze the theory holographically, and propose a dictionary between the Kondo problem and antisymmetric Wilson loops in N = 4 SYM. We perform an explicit calculation of the D5 fluctuations in the D3 geometry and determine the spectrum of defect operators. This establishes the stability of the Kondo fixed point together with its basic thermodynamic properties. Known supergravity solutions for Wilson loops allow us to go beyond the probe approximation: the D5s disappear and are replaced by three-form flux piercing a new topologically non-trivial S3 in the corrected geometry. This describes the Kondo model in terms of a geometric transition. A dual matrix model reflects the basic properties of the corrected gravity solution in its eigenvalue distribution.
Lifetime maximization routing with network coding in wireless multihop networks
DING LiangHui; WU Ping; WANG Hao; PAN ZhiWen; YOU XiaoHu
2013-01-01
In this paper, we consider the lifetime maximization routing with network coding in wireless mul- tihop networks. We first show that lifetime maximization with network coding is different from pure routing, throughput maximization with network coding and energy minimization with network coding. Then we formulate lifetime maximization problems in three different cases of （i） no network coding, （ii） two-way network coding, and （iii） overhearing network coding. To solve these problems, we use flow augmenting routing （FA） for the first case, and then extend the FA with network coding （FANC） by using energy minimized one-hop network coding. After that, we investigate the influence of parameters of FANC, evaluate the performance of FANC with two-way and overhearing network coding schemes and compare it with that without network coding under two different power control models, namely, protocol and physical ones. The results show that the lifetime can be improved significantly by using network coding, and the performance gain of network coding decreases with the increase of flow asymmetry and the power control ability.
Syndromes Associated with Sexually Transmitted Infections
Max Chernesky
2005-01-01
Full Text Available Excellent technologies have been developed to identify the specific microbial agents of chlamydia, gonorrhea, syphilis, herpes, chancroid, trichomoniasis, human papillomavirus and HIV infection. However, it is also crucial to recognize syndromes that may be caused by one or more sexually transmitted pathogens. When laboratory services are lacking or are inadequate to provide timely results to enable appropriate treatment, some patients must be managed and treated syndromically. Most Canadian laboratories should be able to provide diagnostic services to determine the etiology of syndromes such as cervicitis, urethritis, pelvic inflammatory disease, prostatitis, genital ulcers, sexually transmitted infection (STI-related enteric infections, epididymitis, hepatitis, ophthalmia neonatorum, vulvovaginitis and vaginosis.
Munch, G D W; Svendsen, J H; Damsgaard, R; Secher, N H; González-Alonso, J; Mortensen, S P
2014-01-15
In humans, maximal aerobic power (VO2 max ) is associated with a plateau in cardiac output (Q), but the mechanisms regulating the interplay between maximal heart rate (HRmax) and stroke volume (SV) are unclear. To evaluate the effect of tachycardia and elevations in HRmax on cardiovascular function and capacity during maximal exercise in healthy humans, 12 young male cyclists performed incremental cycling and one-legged knee-extensor exercise (KEE) to exhaustion with and without right atrial pacing to increase HR. During control cycling, Q and leg blood flow increased up to 85% of maximal workload (WLmax) and remained unchanged until exhaustion. SV initially increased, plateaued and then decreased before exhaustion (P rate pressure product and RAP (P heart can be paced to a higher HR than observed during maximal exercise, suggesting that HRmax and myocardial work capacity do not limit VO2 max in healthy individuals. A limited left ventricular filling and possibly altered contractility reduce SV during atrial pacing, whereas a plateau in LVFP appears to restrict Q close to VO2 max .
Effect of Menstrual Cycle on Maximal Aerobic Power of Normal ...
Lamina
at an environmental temperature of between 23 to 25 C o and altitude of 481m. ..... Sci Sports Exerc 39(7);1090-7. White, D.P., Douglas N.J., Pickett C.K., Weil J.V. and Zwillich ... J., Coody D.K. , West M.S., Montgomery D. and. Brown M. 1993.
Maximizing the Educational Power of History Movies in the Classroom
Metzger, Scott Alan
2010-01-01
Cinematic feature films are a big part of youth popular culture. When blockbuster movies are about historical topics, it is reasonable for teachers to be drawn to using them in the classroom to motivate students interest. This article overviews research on film in the history classroom and describes three learning functions that history movies can…
Digital media and sexually transmitted infections.
Gilliam, Melissa; Chor, Julie; Hill, Brandon
2014-10-01
Digital media, including the Internet, social networking sites, text messaging, and mobile applications, are ubiquitous among adolescents and young adults. These platforms enable users to obtain important information on a multitude of health topics, they may facilitate risk-taking behaviors, and they can be key components of health interventions. The purpose of this article is to review the recent literature on digital media and sexually transmitted infections, discussing their role in potentiating and reducing risk. This review demonstrates adolescents' use of digital media to gather information on health topics and discusses significant privacy concerns regarding using media to explore sexual health information. Although several studies demonstrate an association between social media and increased sexual risk-taking behaviors, this relationship is not fully understood. Digital media-based interventions are increasingly being developed to either reduce risk or improve management of sexually transmitted infections. As greater numbers of adolescents use digital media, the potential for these platforms to influence sexual risk-taking behaviors is significant. Additional research is needed to better understand the impact of digital media on sexually transmitted infection risk and to develop social media-based interventions to improve sexually transmitted infection outcomes.
Zoonosis that is Transmitted Through Food
Tri Budhi Murdiati
2006-03-01
Full Text Available Zoonosis can be transmitted through a number of routes including food of animal products . Foodborne disease is a disease transmitted through food, while zoonosis is defined as a disease that can be transmitted from animal to man or vice versa . Then, if agent in foodborne disease is a zoonotic, it could be defined as foodborne zoonosis . The outbreaks of Bovine Spongioform Encephalopathy (BSE followed by Avian influenza (AI have caused increasing concern in the food safety of animal products, especially after men were confirmed die from Al infection . Consumers are wondering whether the disease could be transmitted through the animal products from the infected animals . The safety of animal originated food is affected by the practices along the food chain, from farm to consumer plate . Human health hazard could enter the food at any points of the food chain . At the food preparation, some of the foodborne zoonosis can be prevented by the program of five keys for safer food, i .e. keep food clean, separate raw from cooked food, cook food thoroughly, store food at safe temperatures and use water and raw materials that are safe .
Inductive Reasoning about Causally Transmitted Properties
Shafto, Patrick; Kemp, Charles; Bonawitz, Elizabeth Baraff; Coley, John D.; Tenenbaum, Joshua B.
2008-01-01
Different intuitive theories constrain and guide inferences in different contexts. Formalizing simple intuitive theories as probabilistic processes operating over structured representations, we present a new computational model of category-based induction about causally transmitted properties. A first experiment demonstrates undergraduates'…
Maximal inequalities for demimartingales and their applications
WANG XueJun; HU ShuHe
2009-01-01
In this paper,we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides.The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob's type maximal inequality for demimartingales,strong laws of large numbers and growth rate for demimartingales and associated random variables.At last,we give an equivalent condition of uniform integrability for demisubmartingales.
Maximal inequalities for demimartingales and their applications
无
2009-01-01
In this paper, we establish some maximal inequalities for demimartingales which generalize and improve the results of Christofides. The maximal inequalities for demimartingales are used as key inequalities to establish other results including Doob’s type maximal inequality for demimartingales, strong laws of large numbers and growth rate for demimartingales and associated random variables. At last, we give an equivalent condition of uniform integrability for demisubmartingales.
Task-oriented maximally entangled states
Agrawal, Pankaj; Pradhan, B, E-mail: agrawal@iopb.res.i, E-mail: bpradhan@iopb.res.i [Institute of Physics, Sachivalaya Marg, Bhubaneswar, Orissa 751 005 (India)
2010-06-11
We introduce the notion of a task-oriented maximally entangled state (TMES). This notion depends on the task for which a quantum state is used as the resource. TMESs are the states that can be used to carry out the task maximally. This concept may be more useful than that of a general maximally entangled state in the case of a multipartite system. We illustrate this idea by giving an operational definition of maximally entangled states on the basis of communication tasks of teleportation and superdense coding. We also give examples and a procedure to obtain such TMESs for n-qubit systems.
Lin, Huifa; Shin, Won-Yong
2017-01-01
We study secondary random access in multi-input multi-output cognitive radio networks, where a slotted ALOHA-type protocol and successive interference cancellation are used. We first introduce three types of transmit beamforming performed by secondary users, where multiple antennas are used to suppress the interference at the primary base station and/or to increase the received signal power at the secondary base station. Then, we show a simple decentralized power allocation along with the equivalent single-antenna conversion. To exploit the multiuser diversity gain, an opportunistic transmission protocol is proposed, where the secondary users generating less interference are opportunistically selected, resulting in a further reduction of the interference temperature. The proposed methods are validated via computer simulations. Numerical results show that increasing the number of transmit antennas can greatly reduce the interference temperature, while increasing the number of receive antennas leads to a reduction of the total transmit power. Optimal parameter values of the opportunistic transmission protocol are examined according to three types of beamforming and different antenna configurations, in terms of maximizing the cognitive transmission capacity. All the beamforming, decentralized power allocation, and opportunistic transmission protocol are performed by the secondary users in a decentralized manner, thus resulting in an easy implementation in practice.
Inflation in maximal gauged supergravities
Kodama, Hideo [Theory Center, KEK,Tsukuba 305-0801 (Japan); Department of Particles and Nuclear Physics,The Graduate University for Advanced Studies,Tsukuba 305-0801 (Japan); Nozawa, Masato [Dipartimento di Fisica, Università di Milano, and INFN, Sezione di Milano,Via Celoria 16, 20133 Milano (Italy)
2015-05-18
We discuss the dynamics of multiple scalar fields and the possibility of realistic inflation in the maximal gauged supergravity. In this paper, we address this problem in the framework of recently discovered 1-parameter deformation of SO(4,4) and SO(5,3) dyonic gaugings, for which the base point of the scalar manifold corresponds to an unstable de Sitter critical point. In the gauge-field frame where the embedding tensor takes the value in the sum of the 36 and 36’ representations of SL(8), we present a scheme that allows us to derive an analytic expression for the scalar potential. With the help of this formalism, we derive the full potential and gauge coupling functions in analytic forms for the SO(3)×SO(3)-invariant subsectors of SO(4,4) and SO(5,3) gaugings, and argue that there exist no new critical points in addition to those discovered so far. For the SO(4,4) gauging, we also study the behavior of 6-dimensional scalar fields in this sector near the Dall’Agata-Inverso de Sitter critical point at which the negative eigenvalue of the scalar mass square with the largest modulus goes to zero as the deformation parameter s approaches a critical value s{sub c}. We find that when the deformation parameter s is taken sufficiently close to the critical value, inflation lasts more than 60 e-folds even if the initial point of the inflaton allows an O(0.1) deviation in Planck units from the Dall’Agata-Inverso critical point. It turns out that the spectral index n{sub s} of the curvature perturbation at the time of the 60 e-folding number is always about 0.96 and within the 1σ range n{sub s}=0.9639±0.0047 obtained by Planck, irrespective of the value of the η parameter at the critical saddle point. The tensor-scalar ratio predicted by this model is around 10{sup −3} and is close to the value in the Starobinsky model.
Energy-efficient Power Allocation Strategy in Cognitive Relay Networks
Z. Zhang
2012-09-01
Full Text Available Cognitive radio and cooperative technique are two essential techniques for the future generation green communication paradigm owing to its inherent advantages of adaptability and cognition. Typically, previous studies on power allocation in the cognitive relay networks often concentrate on two goals independently: the first goal is to minimize the transmit power to reduce energy consumption, as depicted in strategy 1; the second goal is to maximize the transmit rate, as depicted in strategy 2. In this paper, we shift our focus to energy-efficient-oriented design, that is, green power allocation between source and relay. Therefore, we present a novel power allocation strategy considering the two goals jointly, as depicted in strategy 3, and compare the proposed strategy with two previous strategies. Specifically, because the strategy 3 is nonlinear, we use the Lagrange dual method to solve it effectively. Finally, the numerical results are presented to validate our theoretical results through theory simulation and Monte Carlo simulation. Numerical performance results show that the proposed strategy works better than that of the two previous strategies from the viewpoints of energy-efficient.
A novel utility function for energy-efficient power control game in cognitive radio networks.
Al-Gumaei, Yousef Ali; Noordin, Kamarul Ariffin; Reza, Ahmed Wasif; Dimyati, Kaharudin
2015-01-01
Spectrum scarcity is a major challenge in wireless communications systems requiring efficient usage and utilization. Cognitive radio network (CRN) is found as a promising technique to solve this problem of spectrum scarcity. It allows licensed and unlicensed users to share the same licensed spectrum band. Interference resulting from cognitive radios (CRs) has undesirable effects on quality of service (QoS) of both licensed and unlicensed systems where it causes degradation in received signal-to-noise ratio (SIR) of users. Power control is one of the most important techniques that can be used to mitigate interference and guarantee QoS in both systems. In this paper, we develop a new approach of a distributed power control for CRN based on utility and pricing. QoS of CR user is presented as a utility function via pricing and a distributed power control as a non-cooperative game in which users maximize their net utility (utility-price). We define the price as a real function of transmit power to increase pricing charge of the farthest CR users. We prove that the power control game proposed in this study has Nash Equilibrium as well as it is unique. The obtained results show that the proposed power control algorithm based on a new utility function has a significant reduction in transmit power consumption and high improvement in speed of convergence.
Maximizing Lifetime of Wireless Sensor Networks with Mobile Sink Nodes
Yourong Chen
2014-01-01
Full Text Available In order to maximize network lifetime and balance energy consumption when sink nodes can move, maximizing lifetime of wireless sensor networks with mobile sink nodes (MLMS is researched. The movement path selection method of sink nodes is proposed. Modified subtractive clustering method, k-means method, and nearest neighbor interpolation method are used to obtain the movement paths. The lifetime optimization model is established under flow constraint, energy consumption constraint, link transmission constraint, and other constraints. The model is solved from the perspective of static and mobile data gathering of sink nodes. Subgradient method is used to solve the lifetime optimization model when one sink node stays at one anchor location. Geometric method is used to evaluate the amount of gathering data when sink nodes are moving. Finally, all sensor nodes transmit data according to the optimal data transmission scheme. Sink nodes gather the data along the shortest movement paths. Simulation results show that MLMS can prolong network lifetime, balance node energy consumption, and reduce data gathering latency under appropriate parameters. Under certain conditions, it outperforms Ratio_w, TPGF, RCC, and GRND.
Exact performance analysis of MIMO cognitive radio systems using transmit antenna selection
Tourki, Kamel
2014-03-01
We consider in this paper, a spectrum sharing cognitive radio system with a ratio selection scheme; where one out of N independent-and-identically- distributed transmit antennas is selected such that the ratio of the secondary transmitter (ST) to the secondary receiver (SR) channel gain to the interference from the ST to the primary receiver (PR) channel gain is maximized. Although previous works considered perfect, outdated, or partial channel state information at the transmitter, we stress that using such assumptions may lead to a feedback overhead for updating the SR with the ST-PR interference channel estimation. Considering only statistical knowledge of the ST-PR channel gain, we investigate a ratio selection scheme using a mean value (MV)-based power allocation strategy referred to as MV-based scheme. We first provide the exact statistics in terms of probability density function and cumulative distribution function of the secondary channel gain as well as of the interference channel gain. Furthermore, we derive exact cumulative density function of the received signal-to-noise ratio at the SR where the ST uses a power allocation based on instantaneous perfect channel state information (CSI) referred to as CSI-based scheme. These statistics are then used to derive exact closed form expressions of the outage probability, symbol error rate, and ergodic capacity of the secondary system when the interference channel from the primary transmitter (PT) to the SR is ignored. Furthermore, an asymptotical analysis is also carried out for the MV-based scheme as well as for the CSI-based scheme to derive the generalized diversity gain for each. Subsequently, we address the performance analysis based on exact statistics of the combined signal-to-interference-plus- noise ratio at the SR of the more challenging case; when the PT-SR interference channel is considered. Numerical results in a Rayleigh fading environment manifest that the MV-based scheme outperforms the CSI
High-voltage integrated transmitting circuit with differential driving for CMUTs
Llimos Muntal, Pere; Larsen, Dennis Øland; Færch, Kjartan Ullitz
2016-01-01
In this paper, a high-voltage integrated differential transmitting circuit for capacitive micromachined ultrasonic transducers (CMUTs) used in portable ultrasound scanners is presented. Due to its application, area and power consumption are critical and need to be minimized. The circuitry...... is designed and implemented in AMS 0.35 μ m high-voltage process. Measurements are performed on the fabricated integrated circuit in order to assess its performance. The transmitting circuit consists of a low-voltage control logic, pulse-triggered level shifters and a differential output stage that generates...... pulses at differential voltage levels of 60, 80 and 100 V, a frequency up to 5 MHz and a measured driving strength of 2.03 V/ns with the CMUT electrical model connected. The total on-chip area occupied by the transmitting circuit is 0.18 mm2 and the power consumption at the ultrasound scanner operation...
Computing Maximally Supersymmetric Scattering Amplitudes
Stankowicz, James Michael, Jr.
This dissertation reviews work in computing N = 4 super-Yang--Mills (sYM) and N = 8 maximally supersymmetric gravity (mSUGRA) scattering amplitudes in D = 4 spacetime dimensions in novel ways. After a brief introduction and overview in Ch. 1, the various techniques used to construct amplitudes in the remainder of the dissertation are discussed in Ch. 2. This includes several new concepts such as d log and pure integrand bases, as well as how to construct the amplitude using exactly one kinematic point where it vanishes. Also included in this chapter is an outline of the Mathematica package on shell diagrams and numerics.m (osdn) that was developed for the computations herein. The rest of the dissertation is devoted to explicit examples. In Ch. 3, the starting point is tree-level sYM amplitudes that have integral representations with residues that obey amplitude relations. These residues are shown to have corresponding residue numerators that allow a double copy prescription that results in mSUGRA residues. In Ch. 4, the two-loop four-point sYM amplitude is constructed in several ways, showcasing many of the techniques of Ch. 2; this includes an example of how to use osdn. The two-loop five-point amplitude is also presented in a pure integrand representation with comments on how it was constructed from one homogeneous cut of the amplitude. On-going work on the two-loop n-point amplitude is presented at the end of Ch. 4. In Ch. 5, the three-loop four-point amplitude is presented in the d log representation and in the pure integrand representation. In Ch. 6, there are several examples of four- through seven-loop planar diagrams that illustrate how considerations of the singularity structure of the amplitude underpin dual-conformal invariance. Taken with the previous examples, this is additional evidence that the structure known to exist in the planar sector extends to the full theory. At the end of this chapter is a proof that all mSUGRA amplitudes have a pole at
Are all maximally entangled states pure?
Cavalcanti, D; Terra-Cunha, M O
2005-01-01
In this Letter we study if all maximally entangled states are pure through several entanglement monotones. Our conclusions allow us to generalize the idea of monogamy of entanglement. Then we propose a polygamy of entanglement, which express that if a general multipartite state is maximally entangled it is necessarily factorized by any other system.
Sampling and Representation Complexity of Revenue Maximization
Dughmi, Shaddin; Han, Li; Nisan, Noam
2014-01-01
We consider (approximate) revenue maximization in auctions where the distribution on input valuations is given via "black box" access to samples from the distribution. We observe that the number of samples required -- the sample complexity -- is tightly related to the representation complexity of an approximately revenue-maximizing auction. Our main results are upper bounds and an exponential lower bound on these complexities.
Lisonek, Petr
1996-01-01
our classifications confirmthe maximality of previously known sets, the results in E^7 and E^8are new. Their counterpart in dimension larger than 10is a set of unit vectors with only two values of inner products in the Lorentz space R^{d,1}.The maximality of this set again follows from a bound due...
An ethical justification of profit maximization
Koch, Carsten Allan
2010-01-01
In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing b...
Alternative trailer configurations for maximizing payloads
Jason D. Thompson; Dana Mitchell; John Klepac
2017-01-01
In order for harvesting contractors to stay ahead of increasing costs, it is imperative that they employ all options to maximize productivity and efficiency. Transportation can account for half the cost to deliver wood to a mill. Contractors seek to maximize truck payload to increase productivity. The Forest Operations Research Unit, Southern Research Station, USDA...
Cohomology of Weakly Reducible Maximal Triangular Algebras
董浙; 鲁世杰
2000-01-01
In this paper, we introduce the concept of weakly reducible maximal triangular algebras φwhich form a large class of maximal triangular algebras. Let B be a weakly closed algebra containing 5φ, we prove that the cohomology spaces Hn(φ, B) (n≥1) are trivial.
Bandwidth utilization maximization of scientific RF communication systems
Rey, D. [Sandia National Lab., Albuquerque, NM (United States); Ryan, W. [New Mexico State Univ., Las Cruces, NM (United States); Ross, M.
1997-01-01
A method for more efficiently utilizing the frequency bandwidth allocated for data transmission is presented. Current space and range communication systems use modulation and coding schemes that transmit 0.5 to 1.0 bits per second per Hertz of radio frequency bandwidth. The goal in this LDRD project is to increase the bandwidth utilization by employing advanced digital communications techniques. This is done with little or no increase in the transmit power which is usually very limited on airborne systems. Teaming with New Mexico State University, an implementation of trellis coded modulation (TCM), a coding and modulation scheme pioneered by Ungerboeck, was developed for this application and simulated on a computer. TCM provides a means for reliably transmitting data while simultaneously increasing bandwidth efficiency. The penalty is increased receiver complexity. In particular, the trellis decoder requires high-speed, application-specific digital signal processing (DSP) chips. A system solution based on the QualComm Viterbi decoder and the Graychip DSP receiver chips is presented.
金维刚; 李勇; 印永华; 秦晓辉; 汪文达; 郭晓云
2016-01-01
Of the optimal operation problems of the ultra-high voltage (UHV) transmission corridors,how to select the appropriate transmission capacity and the bundle proportion of wind power and thermal power is especially important for economic and stable operation of power grids.In this paper,a planning method is developed.First,a comprehensive index system,including static security index,transient stability index,voltage stability index,economic operation index,and the power demand index,is established that takes into account the stability,security and economy of the receiving end system. Then based on these indices,the objectives of the mathematical model are defined with multi-objective functions.The non-dominant sorting genetic algorithm-Ⅱ is adopted to solve the multi-objective model.And the non-inferior solutions of the model are treated as transmission alternatives.Moreover,a decision method is adopted to rank the alternatives.Finally,the influences of the change in number of alternatives and different index values on the sorting results are analyzed via probabilistic sensitivity analysis.In addition,changes in the ranking results of schemes using different weighting and decision-making methods as well as the robustness of optimum scheme are analyzed and compared.A regional power network case study is presented to verify the necessity and rationality of the planning method proposed.%在特高压输电通道优化运行问题中，如何选择合适的输电容量和风火打捆配置方案对电网经济稳定运行尤其重要，为此文中提出一种规划方法。首先建立了考虑受端电网稳定性和经济性的静态安全指标、暂态稳定指标、电压稳定指标、经济运行指标和电力电量需求指标的指标体系，在此基础上，建立了多目标优化模型，并采用带精英策略的非支配排序遗传算法(NSGA-Ⅱ)进行求解，得到满足各约束条件的非劣解集，作为风火打捆输电的备选方案；
Inclusive fitness maximization: An axiomatic approach.
Okasha, Samir; Weymark, John A; Bossert, Walter
2014-06-07
Kin selection theorists argue that evolution in social contexts will lead organisms to behave as if maximizing their inclusive, as opposed to personal, fitness. The inclusive fitness concept allows biologists to treat organisms as akin to rational agents seeking to maximize a utility function. Here we develop this idea and place it on a firm footing by employing a standard decision-theoretic methodology. We show how the principle of inclusive fitness maximization and a related principle of quasi-inclusive fitness maximization can be derived from axioms on an individual׳s 'as if preferences' (binary choices) for the case in which phenotypic effects are additive. Our results help integrate evolutionary theory and rational choice theory, help draw out the behavioural implications of inclusive fitness maximization, and point to a possible way in which evolution could lead organisms to implement it. Copyright © 2014 Elsevier Ltd. All rights reserved.
Maximal Hypersurfaces in Spacetimes with Translational Symmetry
Bulawa, Andrew
2016-01-01
We consider four-dimensional vacuum spacetimes which admit a free isometric spacelike R-action. Taking a quotient with respect to the R-action produces a three-dimensional quotient spacetime. We establish several results regarding maximal hypersurfaces (spacelike hypersurfaces of zero mean curvature) in quotient spacetimes. First, we show that complete noncompact maximal hypersurfaces must either be flat cylinders S^1 x R or conformal to the Euclidean plane. Second, we establish a positive mass theorem for certain maximal hypersurfaces. Finally, while it is meaningful to use a bounded lapse when adopting the maximal hypersurface gauge condition in the four-dimensional (asymptotically flat) setting, it is shown here that nontrivial quotient spacetimes admit the maximal hypersurface gauge only with an unbounded lapse.
Advances in understanding paternally transmitted Chromosomal Abnormalities
Marchetti, F; Sloter, E; Wyrobek, A J
2001-03-01
Multicolor FISH has been adapted for detecting the major types of chromosomal abnormalities in human sperm including aneuploidies for clinically-relevant chromosomes, chromosomal aberrations including breaks and rearrangements, and other numerical abnormalities. The various sperm FISH assays have been used to evaluate healthy men, men of advanced age, and men who have received mutagenic cancer therapy. The mouse has also been used as a model to investigate the mechanism of paternally transmitted genetic damage. Sperm FISH for the mouse has been used to detect chromosomally abnormal mouse sperm, while the PAINT/DAPI analysis of mouse zygotes has been used to evaluate the types of chromosomal defects that can be paternally transmitted to the embryo and their effects on embryonic development.
SEXUALLY TRANSMITTED DISEASES： INCIDENCE AND DISTRIBUTION
王千秋
1996-01-01
The incidence of sexually transmitted diseases(STDs) increased from 26. 04 per 10000O in 1987 to 104. 81 per 100 000 in 1993 in selected areas of the country. Gonorrhea is by far the most common STD but its constituent ratio declined because of a rapid increase of nongonococcal uretheritis and genital warts during most recent years. The incidence of syphilis is relatively low and cases of congenital infection are noted. The wide spread of resistant Neisseria gonorrhaeae infection gives a challenge to the therapeutical and control strategies of STDs. Sexually transmitted Chlamydia trachomatis infections, an important cause of urethritis, cervicitis and pelvic inflammatory disease, is becoming common in uur country. Attention has been drawn on viral hepatitis in their means of transmission by sexually behaviors, and also, on the homosexuals, assumed to be the high risk group to catch STDs. Coordinated national efforts to control STDs in China have been taken.
Syndromes Associated with Sexually Transmitted Infections
Max Chernesky; David Patrick; Rosanna Peeling
2005-01-01
Excellent technologies have been developed to identify the specific microbial agents of chlamydia, gonorrhea, syphilis, herpes, chancroid, trichomoniasis, human papillomavirus and HIV infection. However, it is also crucial to recognize syndromes that may be caused by one or more sexually transmitted pathogens. When laboratory services are lacking or are inadequate to provide timely results to enable appropriate treatment, some patients must be managed and treated syndromically. Most Canadian ...
Molecular Diagnostics for Soil-Transmitted Helminths
O'Connell, Elise M.; Nutman, Thomas B.
2016-01-01
Historically, the diagnosis of soil-transmitted helminths (STHs) (e.g., Strongyloides stercoralis, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and Ascaris lumbricoides) has relied on often-insensitive microscopy techniques. Over the past several years, there has been an effort to use molecular diagnostics, particularly quantitative polymerase chain reaction (qPCR), to detect intestinal pathogens. While some platforms have been approved by regulatory bodies (e.g., Food and ...
Maximizing production rates of the Linde Hampson machine
Maytal, B.-Z.
2006-01-01
In contrast to the ideal case of unlimited size recuperator, any real Linde-Hampson machine of finite size recuperator can be optimized to reach the extreme rates of performance. The group of cryocoolers sharing the same size recuperator is optimized in a closed form by determining the corresponding flow rate which maximizes its rate of cold production. For a similar group of liquefiers an optimal flow rate is derived to maximize the rate of production of liquid cryogen. The group of cryocoolers sharing a constant and given flow rate is optimized by shortening the recuperator for reaching a maximum compactness measured by the cooling power per unit size of the recuperator. The optimum conditions are developed for nitrogen and argon. The relevance of this analysis is discussed in the context of practice of fast cooldown Joule-Thomson cryocooling.
Maximizing Cloud Providers Revenues via Energy Aware Allocation Policies
Mazzucco, Michele; Deters, Ralph
2011-01-01
Cloud providers, like Amazon, offer their data centers' computational and storage capacities for lease to paying customers. High electricity consumption, associated with running a data center, not only reflects on its carbon footprint, but also increases the costs of running the data center itself. This paper addresses the problem of maximizing the revenues of Cloud providers by trimming down their electricity costs. As a solution allocation policies which are based on the dynamic powering servers on and off are introduced and evaluated. The policies aim at satisfying the conflicting goals of maximizing the users' experience while minimizing the amount of consumed electricity. The results of numerical experiments and simulations are described, showing that the proposed scheme performs well under different traffic conditions.
Coordinated Scheduling and Power Control in Cloud-Radio Access Networks
Douik, Ahmed
2015-12-01
This paper addresses the joint coordinated scheduling and power control problem in cloud-enabled networks. Consider the downlink of a cloud-radio access network (CRAN), where the cloud is only responsible for the scheduling policy, power control, and synchronization of the transmit frames across the single-antenna base-stations (BS). The transmit frame consists of several time/frequency blocks, called power-zones (PZ). The paper considers the problem of scheduling users to PZs and determining their power levels (PL), by maximizing the weighted sum-rate under the practical constraints that each user cannot be served by more than one base-station, but can be served by one or more power-zones within each base-station frame. The paper solves the problem using a graph theoretical approach by introducing the joint scheduling and power control graph formed by several clusters, where each is formed by a set of vertices, representing the possible association of users, BSs, and PLs for one specific PZ. The problem is, then, formulated as a maximumweight clique problem, in which the weight of each vertex is the sum of the benefits of the individual associations belonging to that vertex. Simulation results suggest that the proposed crosslayer scheme provides appreciable performance improvement as compared to schemes from recent literature.
Are all maximally entangled states pure?
Cavalcanti, D.; Brandão, F. G. S. L.; Terra Cunha, M. O.
2005-10-01
We study if all maximally entangled states are pure through several entanglement monotones. In the bipartite case, we find that the same conditions which lead to the uniqueness of the entropy of entanglement as a measure of entanglement exclude the existence of maximally mixed entangled states. In the multipartite scenario, our conclusions allow us to generalize the idea of the monogamy of entanglement: we establish the polygamy of entanglement, expressing that if a general state is maximally entangled with respect to some kind of multipartite entanglement, then it is necessarily factorized of any other system.
An ethical justification of profit maximization
Koch, Carsten Allan
2010-01-01
In much of the literature on business ethics and corporate social responsibility, it is more or less taken for granted that attempts to maximize profits are inherently unethical. The purpose of this paper is to investigate whether an ethical argument can be given in support of profit maximizing...... behaviour. It is argued that some form of consequential ethics must be applied, and that both profit seeking and profit maximization can be defended from a rule-consequential point of view. It is noted, however, that the result does not apply unconditionally, but requires that certain form of profit (and...
Robust utility maximization in a discontinuous filtration
Jeanblanc, Monique; Ngoupeyou, Armand
2012-01-01
We study a problem of utility maximization under model uncertainty with information including jumps. We prove first that the value process of the robust stochastic control problem is described by the solution of a quadratic-exponential backward stochastic differential equation with jumps. Then, we establish a dynamic maximum principle for the optimal control of the maximization problem. The characterization of the optimal model and the optimal control (consumption-investment) is given via a forward-backward system which generalizes the result of Duffie and Skiadas (1994) and El Karoui, Peng and Quenez (2001) in the case of maximization of recursive utilities including model with jumps.
2017-01-01
This work focuses on the design of transmitting coils in weakly coupled magnetic induction communication systems. We propose several optimization methods that reduce the active, reactive and apparent power consumption of the coil. These problems are formulated as minimization problems, in which the power consumed by the transmitting coil is minimized, under the constraint of providing a required magnetic field at the receiver location. We develop efficient numeric and analytic methods to solve the resulting problems, which are of high dimension, and in certain cases non-convex. For the objective of minimal reactive power an analytic solution for the optimal current distribution in flat disc transmitting coils is provided. This problem is extended to general three-dimensional coils, for which we develop an expression for the optimal current distribution. Considering the objective of minimal apparent power, a method is developed to reduce the computational complexity of the problem by transforming it to an equivalent problem of lower dimension, allowing a quick and accurate numeric solution. These results are verified experimentally by testing a number of coil geometries. The results obtained allow reduced power consumption and increased performances in magnetic induction communication systems. Specifically, for wideband systems, an optimal design of the transmitter coil reduces the peak instantaneous power provided by the transmitter circuitry, and thus reduces its size, complexity and cost. PMID:28192463
Downlink scheduling of multiuser MIMO systems with transmit beamforming
SONG Xing-hua; WU Wei-ling
2008-01-01
This article deals with downlink scheduling for multiuser multiple-input multiple-output (MIMO) systems, where the base station communicates with multiple users simultaneously through transmit beamforming. Most of the existing transmission schemes for multiuser MIMO systems focus on optimizing sum rate performance of the system. The individual quality of service (QoS) requirements (such as packet delay and minimum transmission rate for the data traffic) are rarely considered. In this article, a novel scheduling strategy is proposed, where we try to optimize the global system performance under individual QoS constraints. By performing scheduling into two steps, namely successive user selection and power allocation, the scheduler can achieve efficient resource utilization while maintaining the QoS requirements of all users. Extensive simulations and analysis are given to show the effectiveness of the proposed scheduler.
Vulvovaginitis: promotion of condom use to prevent sexually transmitted disease.
LeVasseur, J J
1992-09-01
Many studies have suggested that merely warning people about the dangers of sexually transmitted diseases (STDs) and urging the use of condoms as protection will not result in widespread use of condoms. Regular condom use appears to be grounded in knowledge of its effectiveness, perception of STD risk, and belief in a partner's acceptance. But these are not the only barriers to condom use. Negotiating condom use often comes at a sensitive stage in intimate relationships, when individuals prefer to avoid such discussions and simply to trust the powerful and compelling feelings of mutual attraction. This review will consider (1) the effectiveness of condoms in preventing STD transmission, (2) barriers to the use of condoms, and (3) recommended strategies to promote acceptance and use of condoms by heterosexual women.
Closed form fourier-based transmit beamforming for MIMO radar
Lipor, John J.
2014-05-01
In multiple-input multiple-output (MIMO) radar setting, it is often desirable to design correlated waveforms such that power is transmitted only to a given set of locations, a process known as beampattern design. To design desired beam-pattern, current research uses iterative algorithms, first to synthesize the waveform covariance matrix, R, then to design the actual waveforms to realize R. In contrast to this, we present a closed form method to design R that exploits discrete Fourier transform and Toeplitz matrix. The resulting covariance matrix fulfills the practical constraints and performance is similar to that of iterative methods. Next, we present a radar architecture for the desired beampattern that does not require the synthesis of covariance matrix nor the design of correlated waveforms. © 2014 IEEE.
Power Scaling of Uplink Massive MIMO Systems With Arbitrary-Rank Channel Means
Zhang, Qi; Jin, Shi; Wong, Kai-Kit; Zhu, Hongbo; Matthaiou, Michail
2014-10-01
This paper investigates the uplink achievable rates of massive multiple-input multiple-output (MIMO) antenna systems in Ricean fading channels, using maximal-ratio combining (MRC) and zero-forcing (ZF) receivers, assuming perfect and imperfect channel state information (CSI). In contrast to previous relevant works, the fast fading MIMO channel matrix is assumed to have an arbitrary-rank deterministic component as well as a Rayleigh-distributed random component. We derive tractable expressions for the achievable uplink rate in the large-antenna limit, along with approximating results that hold for any finite number of antennas. Based on these analytical results, we obtain the scaling law that the users' transmit power should satisfy, while maintaining a desirable quality of service. In particular, it is found that regardless of the Ricean $K$-factor, in the case of perfect CSI, the approximations converge to the same constant value as the exact results, as the number of base station antennas, $M$, grows large, while the transmit power of each user can be scaled down proportionally to $1/M$. If CSI is estimated with uncertainty, the same result holds true but only when the Ricean $K$-factor is non-zero. Otherwise, if the channel experiences Rayleigh fading, we can only cut the transmit power of each user proportionally to $1/\\sqrt M$. In addition, we show that with an increasing Ricean $K$-factor, the uplink rates will converge to fixed values for both MRC and ZF receivers.
The rate of lactate removal after maximal exercise: the effect of intensity during active recovery.
Riganas, C S; Papadopoulou, Z; Psichas, N; Skoufas, D; Gissis, I; Sampanis, M; Paschalis, V; Vrabas, I S
2015-10-01
The aim of the present investigation was to determine the greater rate of lactate removal after a maximal rowing test using different intensities during active recovery. Thirty elite male rowers performed a simulated incremental exercise protocol on rowing ergometer to determine their maximal oxygen uptake and they divided into three equal sized group according to the type of the recovery that followed the assessment. The first group (N.=10) subjected to 20 min of passive recovery, while the second (N.=10) and the third (N.=10) groups performed 20 min of active recovery using the 25% and the 50% of each individual’s maximal power output, respectively. During the recovery period, every two min were performed measurements for the assessment of blood lactate, oxygen consumption and heart rate (HR). It was found that after 10 min of active recovery at 50% and 25% of maximal power output lactate concentration reduced by 43% and 15%, respectively, while during passive recovery lactate concentration found to be slightly elevated by 1%. It was also found that during recovery period, HR, oxygen consumption and pulmonary ventilation was significant elevated at higher exercise intensity compared to lower exercise intensity and passive recovery. It is concluded that in elite male rowers the active recovery provided higher rate of lactate removal compared to passive recovery. Moreover, active recovery at 50% of maximal power output had better results in lactate clearance compared to the active recovery of lower intensity (25% of maximal power output).
On Secure NOMA Systems with Transmit Antenna Selection Schemes
Lei, Hongjiang
2017-08-09
This paper investigates the secrecy performance of a two-user downlink non-orthogonal multiple access systems. Both single-input and single-output and multiple-input and singleoutput systems with different transmit antenna selection (TAS) strategies are considered. Depending on whether the base station has the global channel state information of both the main and wiretap channels, the exact closed-form expressions for the secrecy outage probability (SOP) with suboptimal antenna selection and optimal antenna selection schemes are obtained and compared with the traditional space-time transmission scheme. To obtain further insights, the asymptotic analysis of the SOP in high average channel power gains regime is presented and it is found that the secrecy diversity order for all the TAS schemes with fixed power allocation is zero. Furthermore, an effective power allocation scheme is proposed to obtain the nonzero diversity order with all the TAS schemes. Monte-Carlo simulations are performed to verify the proposed analytical results.
HEALTH INSURANCE: CONTRIBUTIONS AND REIMBURSEMENT MAXIMAL
HR Division
2000-01-01
Affected by both the salary adjustment index on 1.1.2000 and the evolution of the staff members and fellows population, the average reference salary, which is used as an index for fixed contributions and reimbursement maximal, has changed significantly. An adjustment of the amounts of the reimbursement maximal and the fixed contributions is therefore necessary, as from 1 January 2000.Reimbursement maximalThe revised reimbursement maximal will appear on the leaflet summarising the benefits for the year 2000, which will soon be available from the divisional secretariats and from the AUSTRIA office at CERN.Fixed contributionsThe fixed contributions, applicable to some categories of voluntarily insured persons, are set as follows (amounts in CHF for monthly contributions):voluntarily insured member of the personnel, with complete coverage:815,- (was 803,- in 1999)voluntarily insured member of the personnel, with reduced coverage:407,- (was 402,- in 1999)voluntarily insured no longer dependent child:326,- (was 321...
Maximizing throughput by evaluating critical utilization paths
Weeda, P.J.
1991-01-01
Recently the relationship between batch structure, bottleneck machine and maximum throughput has been explored for serial, convergent and divergent process configurations consisting of two machines and three processes. In three of the seven possible configurations a multiple batch structure maximize
Relationship between maximal exercise parameters and individual ...
Relationship between maximal exercise parameters and individual time trial ... It is widely accepted that the ventilatory threshold (VT) is an important ... This study investigated whether the physiological responses during a 20km time trial (TT) ...
Stochastic dynamics for reinfection by transmitted diseases
Barros, Alessandro S.; Pinho, Suani T. R.
2017-06-01
The use of stochastic models to study the dynamics of infectious diseases is an important tool to understand the epidemiological process. For several directly transmitted diseases, reinfection is a relevant process, which can be expressed by endogenous reactivation of the pathogen or by exogenous reinfection due to direct contact with an infected individual (with smaller reinfection rate σ β than infection rate β ). In this paper, we examine the stochastic susceptible, infected, recovered, infected (SIRI) model simulating the endogenous reactivation by a spontaneous reaction, while exogenous reinfection by a catalytic reaction. Analyzing the mean-field approximations of a site and pairs of sites, and Monte Carlo (MC) simulations for the particular case of exogenous reinfection, we obtained continuous phase transitions involving endemic, epidemic, and no transmission phases for the simple approach; the approach of pairs is better to describe the phase transition from endemic phase (susceptible, infected, susceptible (SIS)-like model) to epidemic phase (susceptible, infected, and removed or recovered (SIR)-like model) considering the comparison with MC results; the reinfection increases the peaks of outbreaks until the system reaches endemic phase. For the particular case of endogenous reactivation, the approach of pairs leads to a continuous phase transition from endemic phase (SIS-like model) to no transmission phase. Finally, there is no phase transition when both effects are taken into account. We hope the results of this study can be generalized for the susceptible, exposed, infected, and removed or recovered (SEIRIE) model, for which the state exposed (infected but not infectious), describing more realistically transmitted diseases such as tuberculosis. In future work, we also intend to investigate the effect of network topology on phase transitions when the SIRI model describes both transmitted diseases (σ 1 ).
Photonic-powered cable assembly
Sanderson, Stephen N.; Appel, Titus James; Wrye, IV, Walter C.
2013-01-22
A photonic-cable assembly includes a power source cable connector ("PSCC") coupled to a power receive cable connector ("PRCC") via a fiber cable. The PSCC electrically connects to a first electronic device and houses a photonic power source and an optical data transmitter. The fiber cable includes an optical transmit data path coupled to the optical data transmitter, an optical power path coupled to the photonic power source, and an optical feedback path coupled to provide feedback control to the photonic power source. The PRCC electrically connects to a second electronic device and houses an optical data receiver coupled to the optical transmit data path, a feedback controller coupled to the optical feedback path to control the photonic power source, and a photonic power converter coupled to the optical power path to convert photonic energy received over the optical power path to electrical energy to power components of the PRCC.
Simple technique for maximal thoracic muscle harvest.
Marshall, M Blair; Kaiser, Larry R; Kucharczuk, John C
2004-04-01
We present a modification of technique for standard muscle flap harvest, the placement of cutaneous traction sutures. This technique allows for maximal dissection of the thoracic muscles even through minimal incisions. Through improved exposure and traction, complete dissection of the muscle bed can be performed and the tissue obtained maximized. Because more muscle bulk is obtained with this technique, the need for a second muscle may be prevented.
MAXIMAL POINTS OF A REGULAR TRUTH FUNCTION
Every canonical linearly separable truth function is a regular function, but not every regular truth function is linearly separable. The most...promising method of determining which of the regular truth functions are linearly separable r quires finding their maximal and minimal points. In this...report is developed a quick, systematic method of finding the maximal points of any regular truth function in terms of its arithmetic invariants. (Author)
Maximal Subgroups of Skew Linear Groups
M. Mahdavi-Hezavehi
2002-01-01
Let D be an infinite division algebra of finite dimension over its centre Z(D) = F, and n a positive integer. The structure of maximal subgroups of skew linear groups are investigated. In particular, assume N is a normal subgroup of GLn(D) and M is a maximal subgroup of N containing Z(N). It is shown that if M/Z(N) is finite, then N is central.
Additive Approximation Algorithms for Modularity Maximization
Kawase, Yasushi; Matsui, Tomomi; Miyauchi, Atsushi
2016-01-01
The modularity is a quality function in community detection, which was introduced by Newman and Girvan (2004). Community detection in graphs is now often conducted through modularity maximization: given an undirected graph $G=(V,E)$, we are asked to find a partition $\\mathcal{C}$ of $V$ that maximizes the modularity. Although numerous algorithms have been developed to date, most of them have no theoretical approximation guarantee. Recently, to overcome this issue, the design of modularity max...
CMA Performance in CDMA Transmit Diversity System
ZHAO Jing-hua; FENG Guang-zeng
2005-01-01
Plenty of work have been done on Space-Time processing in which multiple transmit/receive antennas are used in conjunction with coding to exploit both spatial diversity and time diversity. Constant Mode Algorithm (CMA) is an efficient blind adaptive Multi-User Detection (MUD) algorithm for CDMA systems. In this paper, we put forward a novel receiver, which combines CMA blind adaptive Multi-user Detection with STBC technique, and compare the performances of the system using different CM algorithms including SDCMA (Steepest-Descent CMA), Standard Linearity Confine CMA(SLCCMA) and Least Squares CMA(LSCMA). Simulations have been done with multi-path Rayleigh channel.
Hydrostatic limits of 11 pressure transmitting media
Klotz, S.; Chervin, J.-C.; Munsch, P.; LeMarchand, G.
2009-04-01
We present a systematic and comparative study of the pressure-induced solidification of 11 frequently used pressure transmitting fluids using the ruby fluorescence technique in a diamond anvil cell. These fluids are 1 : 1 and 5 : 1 iso-n pentane, 4 : 1 deuterated methanol-ethanol, 16 : 3 : 1 deuterated methanol-ethanol-water, 1 : 1 FC84-FC87 Fluorinert, Daphne 7474, silicone oil, as well as nitrogen, neon, argon and helium. The data provide practical guidelines for the use of these fluids in high pressure experiments up to 50 GPa.
Reducing Transmitted Vibration Using Delayed Hysteretic Suspension
Lahcen Mokni
2011-01-01
Full Text Available Previous numerical and experimental works show that time delay technique is efficient to reduce transmissibility of vibration in a single pneumatic chamber by controlling the pressure in the chamber. The present work develops an analytical study to demonstrate the effectiveness of such a technique in reducing transmitted vibrations. A quarter-car model is considered and delayed hysteretic suspension is introduced in the system. Analytical predictions based on perturbation analysis show that a delayed hysteretic suspension enhances vibration isolation comparing to the case where the nonlinear damping is delay-independent.
Discourse on the values transmitted in universities Uganda ...
Discourse on the values transmitted in universities Uganda. ... suitability of the knowledge and values offered in African universities has been a matter ... It was found that material, social/ public, personal and religious values are transmitted to ...
Common Culex Mosquitoes Don't Transmit Zika Virus
... 161186.html Common Culex Mosquitoes Don't Transmit Zika Virus: Study These widespread insects do spread West Nile ... t appear to be able to transmit the Zika virus to people, researchers report. The researchers at Kansas ...
Location Based Throughput Maximization Routing in Energy Constrained Mobile Ad-hoc Network
V. Sumathy
2006-01-01
Full Text Available In wireless Ad-hoc network, power consumption becomes an important issue due to limited battery power. One of the reasons for energy expenditure in this network is irregularly distributed node pattern, which impose large interference range in certain area. To maximize the lifetime of ad-hoc mobile network, the power consumption rate of each node must be evenly distributed and the over all transmission range of each node must be minimized. Our protocol, Location based throughput maximization routing in energy constrained Ad-hoc network finds routing paths, which maximize the lifetime of individual nodes and minimize the total transmission energy consumption. The life of the entire network is increased and the network throughput is also increased. The reliability of the path is also increased. Location based energy constrained routing finds the distance between the nodes. Based on the distance the transmission power required is calculated and dynamically reduces the total transmission energy.
Maximal Frequent Itemset Generation Using Segmentation Apporach
M.Rajalakshmi
2011-09-01
Full Text Available Finding frequent itemsets in a data source is a fundamental operation behind Association Rule Mining.Generally, many algorithms use either the bottom-up or top-down approaches for finding these frequentitemsets. When the length of frequent itemsets to be found is large, the traditional algorithms find all thefrequent itemsets from 1-length to n-length, which is a difficult process. This problem can be solved bymining only the Maximal Frequent Itemsets (MFS. Maximal Frequent Itemsets are frequent itemsets whichhave no proper frequent superset. Thus, the generation of only maximal frequent itemsets reduces thenumber of itemsets and also time needed for the generation of all frequent itemsets as each maximal itemsetof length m implies the presence of 2m-2 frequent itemsets. Furthermore, mining only maximal frequentitemset is sufficient in many data mining applications like minimal key discovery and theory extraction. Inthis paper, we suggest a novel method for finding the maximal frequent itemset from huge data sourcesusing the concept of segmentation of data source and prioritization of segments. Empirical evaluationshows that this method outperforms various other known methods.
Natural selection and the maximization of fitness.
Birch, Jonathan
2016-08-01
The notion that natural selection is a process of fitness maximization gets a bad press in population genetics, yet in other areas of biology the view that organisms behave as if attempting to maximize their fitness remains widespread. Here I critically appraise the prospects for reconciliation. I first distinguish four varieties of fitness maximization. I then examine two recent developments that may appear to vindicate at least one of these varieties. The first is the 'new' interpretation of Fisher's fundamental theorem of natural selection, on which the theorem is exactly true for any evolving population that satisfies some minimal assumptions. The second is the Formal Darwinism project, which forges links between gene frequency change and optimal strategy choice. In both cases, I argue that the results fail to establish a biologically significant maximization principle. I conclude that it may be a mistake to look for universal maximization principles justified by theory alone. A more promising approach may be to find maximization principles that apply conditionally and to show that the conditions were satisfied in the evolution of particular traits.
2010-04-01
... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Good faith requests for transmission services and good faith responses by transmitting utilities. 2.20 Section 2.20 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY GENERAL...
Reliability and validity of the maximal anaerobic running test.
Nummela, A; Alberts, M; Rijntjes, R P; Luhtanen, P; Rusko, H
1996-07-01
Physically active men (n = 13) twice performed the Maximal Anaerobic Running Test (MART) on a treadmill and once the Wingate Anaerobic Test (WAnT) on a cycle ergometer. The MART consisted of n 20-s runs with 100-s recovery between the runs. The speed of the first run was 14.6 km.h-1 and the inclination 4 degrees. Thereafter, the speed was increased by 1.37 km.h-1 every run until exhaustion. During all tests oxygen uptake was measured breath-by-breath and blood samples were taken from the fingertip 40s after each run to determine the lactate concentration (BLa). Power at submaximal BLa levels and maximal power (P5mM, P10mM and Pmax, respectively) were calculated and P was expressed as the oxygen demand of running according to the American College of Sports Medicine equation. In the MART the Pmax was 108 ml.kg-1.min-1 and peak BLa was 15.6 mM. The reliability for the power indices in the MART were as follows: r = 0.92 (p cycle ergometer test measure slightly different qualities.
Sexually transmitted diseases treatment guidelines, 2015.
Workowski, Kimberly A; Bolan, Gail A
2015-06-05
These guidelines for the treatment of persons who have or are at risk for sexually transmitted diseases (STDs) were updated by CDC after consultation with a group of professionals knowledgeable in the field of STDs who met in Atlanta on April 30-May 2, 2013. The information in this report updates the Sexually Transmitted Diseases Treatment Guidelines, 2010 (MMWR Recomm Rep 2010;59 [No. RR-12]). These updated guidelines discuss 1) alternative treatment regimens for Neisseria gonorrhoeae; 2) the use of nucleic acid amplification tests for the diagnosis of trichomoniasis; 3) alternative treatment options for genital warts; 4) the role of Mycoplasma genitalium in urethritis/cervicitis and treatment-related implications; 5) updated HPV vaccine recommendations and counseling messages; 6) the management of persons who are transgender; 7) annual testing for hepatitis C in persons with HIV infection; 8) updated recommendations for diagnostic evaluation of urethritis; and 9) retesting to detect repeat infection. Physicians and other health-care providers can use these guidelines to assist in the prevention and treatment of STDs.
Sexually transmitted diseases treatment guidelines, 2010.
Workowski, Kimberly A; Berman, Stuart
2010-12-17
These guidelines for the treatment of persons who have or are at risk for sexually transmitted diseases (STDs) were updated by CDC after consultation with a group of professionals knowledgeable in the field of STDs who met in Atlanta on April 18-30, 2009. The information in this report updates the 2006 Guidelines for Treatment of Sexually Transmitted Diseases (MMWR 2006;55[No. RR-11]). Included in these updated guidelines is new information regarding 1) the expanded diagnostic evaluation for cervicitis and trichomoniasis; 2) new treatment recommendations for bacterial vaginosis and genital warts; 3) the clinical efficacy of azithromycin for chlamydial infections in pregnancy; 4) the role of Mycoplasma genitalium and trichomoniasis in urethritis/cervicitis and treatment-related implications; 5) lymphogranuloma venereum proctocolitis among men who have sex with men; 6) the criteria for spinal fluid examination to evaluate for neurosyphilis; 7) the emergence of azithromycin-resistant Treponema pallidum; 8) the increasing prevalence of antimicrobial-resistant Neisseria gonorrhoeae; 9) the sexual transmission of hepatitis C; 10) diagnostic evaluation after sexual assault; and 11) STD prevention approaches.
The psychological aspects in sexually transmitted infections.
Campolmi, Eleonora; Santosuosso, Ugo; Silvestri, Caterina; Giomi, Barbara; Zuccati, Giuliano
2016-04-01
Over the last years the number of sexually transmitted diseases has greatly increased. This can be attributed mainly to less rigidity in the gender role and to the ever growing sexual liberalization. Sexuality today as in the past, represents an important and complex dimension of the human being. With respect to the psychological area many authors think that there are specific personality traits that to a higher extent compared to others might push individuals to carry out inconsiderate behavior among which there has been found a higher risk of sexually transmitted diseases (STD). In the present paper preliminary data of a research carried out provides information about sexual habits among patients of the IST of Florence. A sample of 344 individuals, from 15 to over 70-year-old, Italians and strangers, has been asked to fill up a self-administered questionnaire. Through these data the psychological aspects at the base of sexual habits in our reference sample are highlighted even more clearly. Through the analysis of these data it will be possible to get a larger number of information that can be used for the building of psychological support experiences that take into account the individual differences among patients one finds through consultations and support. The psychological support is very important for a lot of patients who belong to the center and show inappropriate sexual behavior and exposed to risky sexual behavior.
[Risk of transfusional-transmitted infections].
Blejer, Jorgelina L; Carreras Vescio, Luis A; Salamone, Horacio J
2002-01-01
Although each donated unit of blood is tested for evidence of infection by specific agents, there are at least four potential reasons why transmission of these agents may still occur: a) the donor has negative laboratory test results during the early stages of infection, known as the window period, b) the existence of a chronic carrier state in which a clinically asymptomatic donor will persistently test negative on a screening assay, c) donors harbouring a mutant or atypical variant and d) laboratory errors when performing the screening tests. Measures to assure the safety of blood and blood components include use of voluntary donors, donor selection and questioning, laboratory testing for serological markers of infections, maintenance of registries of disqualified donors and, more recently, the introduction of direct testing for viral nucleic acids. All these measures must be accompanied by rigorous quality control systems. The potential risk of transfusion-transmitted infectious diseases can be estimated by reviewing the records of blood donations, the screening procedures and determining the prevalence of the serologic markers of infectious diseases. Accurate estimates of the risk of transfusion-transmitted infections are needed in order to monitor the safety of the blood supply and evaluate the yield and cost effectiveness of alternatives to allogeneic transfusion. Genomic screening for infectious agents, especially viruses, became possible with the development of various nucleic acid amplification techniques. They combine the advantages of direct detection of the organism with a sensitivity several orders of magnitude higher than that of traditional methods.
Phase-only nulling for transmit antenna
Hussain, Moayyed A.; Yu, Kai-Bor
1999-11-01
This paper describes a technique for transmit antenna nulling for low-cost large sparse phased array radar system. Radar system described includes an array of elemental antennas, each with a transmit/receive (T/R) module. The T/R modules are operated at or near maximum output to achieve maximum CD-to-RF efficiency. A phase controller controls the phase shift, which are imparted by each module to its signal, to form a mainbeam and its associated sidelobes. A perturbation phase generator adds phase shifts computed, to form wide nulls in the sidelobe structure. The nulls are achieved at very minimal loss of gain, in the order of fraction of a dB. The speed of obtaining these nulls in real time allows a rapid steering of these nulls in a hostile environment. The thinned aperture allow designing a light weigh mobile system. In radar context, these nulls may be placed on a source of ground clutter, a set of jammers or a set of undesirable radio sources.
Interference Alignment with Partially Coordinated Transmit Precoding
Yousafzai, Aimal Khan
2011-01-01
In this paper, we introduce an efficient interference alignment (IA) algorithm exploiting partially coordinated transmit precoding to improve the number of concurrent interference-free transmissions, i.e., the multiplexing gain, in multicell downlink. The proposed coordination model is such that each base-station simultaneously transmits to two users and each user is served by two base-stations. First, we show in a K-user system operating at the information theoretic upper bound of degrees of freedom (DOF), the generic IA is proper when $K \\leq 3$, whereas the proposed partially coordinated IA is proper when $K \\leq 5$. Then, we derive a non-iterative, i.e., one shot, IA algorithm for the proposed scheme when $K \\leq 5$. We show that for a given latency, the backhaul data rate requirement of the proposed method grows linearly with K. Monte-Carlo simulation results show that the proposed one-shot algorithm offers higher system throughput than the iterative IA at practical SNR levels.
Multiple routes transmitted epidemics on multiplex networks
Zhao, Dawei [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Shandong Provincial Key Laboratory of Computer Network, Shandong Computer Science Center, Jinan 250014 (China); Li, Lixiang [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Peng, Haipeng, E-mail: penghaipeng@bupt.edu.cn [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Luo, Qun; Yang, Yixian [Information Security Center, State Key Laboratory of Networking and Switching Technology, Beijing University of Posts and Telecommunications, P.O. Box 145, Beijing 100876 (China); National Engineering Laboratory for Disaster Backup and Recovery, Beijing University of Posts and Telecommunications, Beijing 100876 (China)
2014-02-01
This letter investigates the multiple routes transmitted epidemic process on multiplex networks. We propose detailed theoretical analysis that allows us to accurately calculate the epidemic threshold and outbreak size. It is found that the epidemic can spread across the multiplex network even if all the network layers are well below their respective epidemic thresholds. Strong positive degree–degree correlation of nodes in multiplex network could lead to a much lower epidemic threshold and a relatively smaller outbreak size. However, the average similarity of neighbors from different layers of nodes has no obvious effect on the epidemic threshold and outbreak size. -- Highlights: •We studies multiple routes transmitted epidemic process on multiplex networks. •SIR model and bond percolation theory are used to analyze the epidemic processes. •We derive equations to accurately calculate the epidemic threshold and outbreak size. •ASN has no effect on the epidemic threshold and outbreak size. •Strong positive DDC leads to a lower epidemic threshold and a smaller outbreak size.
Prevention of soil-transmitted helminth infection
Luciene Mascarini-Serra
2011-01-01
Full Text Available Soil-transmitted helminths (STHs form one of the most important groups of infectious agents and are the cause of serious global health problems. The most important STHs are roundworms (Ascaris lumbricoides, whipworms (Trichuris trichiura and hookworms (Necator americanus or Ancylostoma duodenale; on a global level, more than a billion people have been infected by at least one species of this group of pathogens. This review explores the general concepts of transmission dynamics and the environment and intensity of infection and morbidity of STHs. The global strategy for the control of soil-transmitted helminthiasis is based on (i regular anthelminthic treatment, (ii health education, (iii sanitation and personal hygiene and (iv other means of prevention with vaccines and remote sensoring. The reasons for the development of a control strategy based on population intervention rather than on individual treatment are discussed, as well as the costs of the prevention of STHs, although these cannot always be calculated because interventions in health education are difficult to measure. An efficient sanitation infrastructure can reduce the morbidity of STHs and eliminates the underlying cause of most poverty-related diseases and thus supports the economic development of a country.
Tun, F A Hla Myo; Naing, T C Zaw Min
2010-01-01
In this paper, the minimum channel gain flow with uncertainty in the demand vector is examined. The approach is based on a transformation of uncertainty in the demand vector to uncertainty in the gain vector. OFDM systems are known to overcome the impairment of the wireless channel by splitting the given system bandwidth into parallel sub-carriers, on which data-symbols can be transmitted simultaneously. This enables the possibility of enhancing the system's performance by deploying adaptive mechanisms, namely power distribution and dynamic sub-carrier assignments. The performances of maximizing the minimum throughput have been analyzed by MATLAB codes.
Radaydeh, Redha Mahmoud Mesleh
2010-01-01
The performance of transmit antenna selection for threshold-based maximal ratio combining (MRC) diversity receivers in the presence of multiple co-channel interfering signals is studied. The impact of imperfect channel estimation of desired user signals is considered, and the effect of phase and time misalignments between desired and undesired signals is incorporated in the analysis. Precise formulation for Nakagami-m faded interfering signals is presented. The analysis is applicable for arbitrary transmit antenna selection, which is based on the receiver combined signal-to-noise ratios (SNRs) or combined signal-to-interference-plus-noise ratios (SINRs) for different transmit channels. New expressions for the distribution of combined SINR and outage probability performance are derived considering SNR-based as well as SINR-based selection algorithms. The results can be used to study the performance of different system architectures under various channel conditions when the implementation complexity is of interest. ©2010 IEEE.
Transmit Array Interpolation for DOA Estimation via Tensor Decomposition in 2-D MIMO Radar
Cao, Ming-Yang; Vorobyov, Sergiy A.; Hassanien, Aboulnasr
2017-10-01
In this paper, we propose a two-dimensional (2D) joint transmit array interpolation and beamspace design for planar array mono-static multiple-input-multiple-output (MIMO) radar for direction-of-arrival (DOA) estimation via tensor modeling. Our underlying idea is to map the transmit array to a desired array and suppress the transmit power outside the spatial sector of interest. In doing so, the signal-tonoise ratio is improved at the receive array. Then, we fold the received data along each dimension into a tensorial structure and apply tensor-based methods to obtain DOA estimates. In addition, we derive a close-form expression for DOA estimation bias caused by interpolation errors and argue for using a specially designed look-up table to compensate the bias. The corresponding Cramer-Rao Bound (CRB) is also derived. Simulation results are provided to show the performance of the proposed method and compare its performance to CRB.
Information guided channel hopping with an arbitrary number of transmit antennas
Yang, Yuli
2012-10-01
In order to realize the information guided channel hopping, also known as spatial modulation, with more design flexibility, in this paper we propose a novel scheme that allows operation with an arbitrary number of transmit antennas. Once the number of transmit antennas is not a power of two, the antennas\\' symbols are mapped by different numbers of bits. Subsequently, constellations with different orders are exploited for the modulation of radiated symbols so as to guarantee that the total number of bits transmitted at each time slot remains the same. Furthermore, we introduce a decoding algorithm with low complexity for this design. Numerical results on bit error rate performance are provided and substantiate that the proposed scheme turns out to be a promising alternative to the design of information guided channel hopping. © 2012 IEEE.
Joint Power and Resource Allocation for Block-Fading Relay-Assisted Broadcast Channels
Shaqfeh, Mohammad
2012-01-01
We provide the solution for optimizing the power and resource allocation over block-fading relay-assisted broadcast channels in order to maximize the long term average achievable rates region of the users. The problem formulation assumes regenerative (repetition coding) decode-and-forward (DF) relaying strategy, long-term average total transmitted power constraint, orthogonal multiplexing of the users messages within the channel blocks, possibility to use a direct transmission (DT) mode from the base station to the user terminal directly or a relaying (DF) transmission mode, and partial channel state information. We show that our optimization problem can be transformed into an equivalent "no-relaying" broadcast channel optimization problem with each actual user substituted by two virtual users having different channel qualities and multiplexing weights. The proposed power and resource allocation strategies are expressed in closed-form that can be applied practically in centralized relay-assisted wireless netw...
Benkhelifa, Fatma
2015-05-01
In this paper, we investigate the simultaneous wireless information and power transfer (SWIPT) for a decode-and-forward (DF) multiple-input multiple-output (MIMO) relay system where the relay is an energy harvesting node. We consider the ideal scenario where both the energy harvesting (EH) receiver and information decoding (ID) receiver at the relay have access to the whole received signal and its energy. The relay harvests the energy while receiving the signal from the source and uses the harvested power to forward the signal to the destination. We obtain the optimal precoders at the source and the relay to maximize the achievable throughput rate of the overall link. In the numerical results, the effect of the transmit power at the source and the position of the relay between the source and the destination on the maximum achievable rate are investigated. © 2015 IEEE.
Gribov ambiguities at the Landau -- maximal Abelian interpolating gauge
Pereira, A D
2014-01-01
In a previous work, we presented a new method to account for the Gribov ambiguities in non-Abelian gauge theories. The method consists on the introduction of an extra constraint which directly eliminates the infinitesimal Gribov copies without the usual geometric approach. Such strategy allows to treat gauges with non-hermitian Faddeev-Popov operator. In this work, we apply this method to a gauge which interpolates among the Landau and maximal Abelian gauges. The result is a local and power counting renormalizable action, free of infinitesimal Gribov copies. Moreover, the interpolating tree-level gluon propagator is derived.
Tango's maximized excess events test with different weights
Kulldorff Martin
2005-12-01
Full Text Available Abstract Background Tango's maximized excess events test (MEET has been shown to have very good statistical power in detecting global disease clustering. A nice feature of this test is that it considers a range of spatial scale parameters, adjusting for the multiple testing. This means that it has good power to detect a wide range of clustering processes. The test depends on the functional form of a weight function, and it is unknown how sensitive the test is to the choice of this weight function and what function provides optimal power for different clustering processes. In this study, we evaluate the performance of the test for a wide range of weight functions. Results The power varies greatly with different choice of weight. Tango's original choice for the weight function works very well. There are also other weight functions that provide good power. Conclusion We recommend the use of Tango's MEET to test global disease clustering, either with the original weight or one of the alternate weights that have good power.
A proof that the maximal rank for plane quartics is seven
Alessandro De Paris
2015-12-01
Full Text Available At the time of writing, the general problem of finding the maximal Waring rank for homogeneous polynomials of fixed degree and number of variables (or, equivalently, the maximal symmetric rank for symmetric tensors of fixed order and in fixed dimension is still unsolved. To our knowledge, the answer for ternary quartics is not widely known and can only be found among the results of a master's thesis by Johannes Kleppe at the University of Oslo (1999. In the present work we give a (direct proof that the maximal rank for plane quartics is seven, following the elementary geometric idea of splitting power sum decompositions along three suitable lines.
Tu-Liang Lin
2016-08-01
Full Text Available Traditional sensor nodes are usually battery powered, and the limited battery power constrains the overall lifespan of the sensors. Recently, wireless power transmission technology has been applied in wireless sensor networks (WSNs to transmit wireless power from the chargers to the sensor nodes and solve the limited battery power problem. The combination of wireless sensors and wireless chargers forms a new type of network called wireless rechargeable sensor networks (WRSNs. In this research, we focus on how to effectively deploy chargers to maximize the lifespan of a network. In WSNs, the sensor nodes near the sink consume more power than nodes far away from the sink because of frequent data forwarding. This important power unbalanced factor has not been considered, however, in previous charger deployment research. In this research, a power balance aware deployment (PBAD method is proposed to address the power unbalance in WRSNs and to design the charger deployment with maximum charging efficiency. The proposed deployment method is effectively aware of the existence of the sink node that would cause unbalanced power consumption in WRSNs. The simulation results show that the proposed PBAD algorithm performs better than other deployment methods, and fewer chargers are deployed as a result.
Welfare-maximizing and revenue-maximizing tariffs with a few domestic firms
Bruno Larue; Jean-Philippe Gervais
2002-01-01
In this paper we compare the orthodox optimal tariff formula with the appropriate welfare-maximizing tariff when there are a few producing or importing firms. The welfare-maximizing tariff can be very low, voire negative in some cases, while in others it can even exceed the maximum-revenue tariff. The relationship between the welfare-maximizing tariff and the number of firms need not be monotonically increasing, because the tariff is not strictly used to internalize terms of trade externality...
Crosby, Richard A.; Danner, Fred
2008-01-01
Background: Estimates suggest that about 48% of nearly 19 million cases of sexually transmitted diseases (STDs) occurring annually in the United States are acquired by persons aged 15-24 years. The purpose of this study was to test the hypothesis that adolescents' attitudes about protecting themselves from STDs predict their laboratory-confirmed…
Maximizing Complementary Quantities by Projective Measurements
M. Souza, Leonardo A.; Bernardes, Nadja K.; Rossi, Romeu
2017-04-01
In this work, we study the so-called quantitative complementarity quantities. We focus in the following physical situation: two qubits ( q A and q B ) are initially in a maximally entangled state. One of them ( q B ) interacts with a N-qubit system ( R). After the interaction, projective measurements are performed on each of the qubits of R, in a basis that is chosen after independent optimization procedures: maximization of the visibility, the concurrence, and the predictability. For a specific maximization procedure, we study in detail how each of the complementary quantities behave, conditioned on the intensity of the coupling between q B and the N qubits. We show that, if the coupling is sufficiently "strong," independent of the maximization procedure, the concurrence tends to decay quickly. Interestingly enough, the behavior of the concurrence in this model is similar to the entanglement dynamics of a two qubit system subjected to a thermal reservoir, despite that we consider finite N. However, the visibility shows a different behavior: its maximization is more efficient for stronger coupling constants. Moreover, we investigate how the distinguishability, or the information stored in different parts of the system, is distributed for different couplings.
A Review Paper on Power Consumption Improvements in WSN
Mallika Mhatre
2016-06-01
Full Text Available : Wireless Sensor network (WSN is a network of low-cost, low-power, multifunctional, small size sensor nodes which are densely deployed inside a physical environment to collect, process and transmit the information to sink node. As Sensor nodes are generally battery-powered, it is necessary to balance between power consumption and energy storage capacity to sustain sensor node's operational life. Therefore one of the important challenge in WSN is to improve power consumption efficiently to prolong network lifetime by minimizing the amount of data transmissions throughout the network and maximizing node's low power residence time. In this paper, two energy optimization techniques, Cluster-Based energy efficient routing (CBER scheme and extension to IEEE 802.15.4 standard by dynamic rate adaption and control for energy reduction (DRACER protocol for wireless sensor networks has been reviewed. CBER technique increases network lifetime by reducing Hot Spot problem and end-to-end energy consumption using multi-hop wireless routing whereas DRACER protocol reduces network latency and average power consumption by minimizing network overhead using automatic data rate selection process. So, both of these techniques, if utilized in combination, it is possible to achieve very high energy efficiency in WSN.
Powering low-power implants using PZT transducer discs operated in the radial mode
Sanni, Ayodele; Vilches, Antonio
2013-11-01
This paper reports experimental results that are used to compare operation characteristics of lead zirconate titanate (PZT) piezoelectric ceramic discs operated in the radial mode. The devices are driven to radially vibrate at their lowest fundamental resonant frequency and thus transmit and receive power when immersed in a liquid phantom. A number of 1 mm × 10 mm (thickness × diameter) PZT discs are characterized experimentally within a propagation tank and results discussed. On the basis of these measured characteristics, a novel application is developed and reported for the first time. This consists of a tuned LC resonator circuit which is used at the receiving disc to maximize sensitivity as well as a Seiko start-up IC S-882Z which is employed to charge a capacitor that drives a PIC microcontroller (μC) once the voltage exceeds 2 V DC. We show that a mean input power of 486 mW RMS results in 976 μW RMS received over a range of 80 mm and that this is sufficient to periodically (every 60 s) power the μC to directly drive a red LED for 5 ms with a current of 4.8 mA/flash. This approach is suitable for low-power, periodically activated analogue bio-implant applications.
Optimal Energy Management for a Smart Grid using Resource-Aware Utility Maximization
Abegaz, Brook W.; Mahajan, Satish M.; Negeri, Ebisa O.
2016-06-01
Heterogeneous energy prosumers are aggregated to form a smart grid based energy community managed by a central controller which could maximize their collective energy resource utilization. Using the central controller and distributed energy management systems, various mechanisms that harness the power profile of the energy community are developed for optimal, multi-objective energy management. The proposed mechanisms include resource-aware, multi-variable energy utility maximization objectives, namely: (1) maximizing the net green energy utilization, (2) maximizing the prosumers' level of comfortable, high quality power usage, and (3) maximizing the economic dispatch of energy storage units that minimize the net energy cost of the energy community. Moreover, an optimal energy management solution that combines the three objectives has been implemented by developing novel techniques of optimally flexible (un)certainty projection and appliance based pricing decomposition in an IBM ILOG CPLEX studio. A real-world, per-minute data from an energy community consisting of forty prosumers in Amsterdam, Netherlands is used. Results show that each of the proposed mechanisms yields significant increases in the aggregate energy resource utilization and welfare of prosumers as compared to traditional peak-power reduction methods. Furthermore, the multi-objective, resource-aware utility maximization approach leads to an optimal energy equilibrium and provides a sustainable energy management solution as verified by the Lagrangian method. The proposed resource-aware mechanisms could directly benefit emerging energy communities in the world to attain their energy resource utilization targets.
Optical antenna gain. I - Transmitting antennas
Klein, B. J.; Degnan, J. J.
1974-01-01
The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM-00 mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.
Optical antenna gain. 1: transmitting antennas.
Klein, B J; Degnan, J J
1974-09-01
The gain of centrally obscured optical transmitting antennas is analyzed in detail. The calculations, resulting in near- and far-field antenna gain patterns, assume a circular antenna illuminated by a laser operating in the TEM(00) mode. A simple polynomial equation is derived for matching the incident source distribution to a general antenna configuration for maximum on-axis gain. An interpretation of the resultant gain curves allows a number of auxiliary design curves to be drawn that display the losses in antenna gain due to pointing errors and the cone angle of the beam in the far field as a function of antenna aperture size and its central obscuration. The results are presented in a series of graphs that allow the rapid and accurate evaluation of the antenna gain which may then be substituted into the conventional range equation.
Sexually Transmitted Disease and Male Infertility
Fode, Mikkel; Fusco, Ferdinando; Lipshultz, Larry
2016-01-01
CONTEXT: Theoretically, sexually transmitted diseases (STDs) have the potential to disrupt male fertility; however, the topic remains controversial. OBJECTIVE: To describe the possible association between STDs and male infertility and to explore possible pathophysiologic mechanisms. EVIDENCE...... ACQUISITION: We performed a systematic literature review in accordance with the PRISMA guidelines. PubMed, Embase, and the Cochrane Library were searched for articles published before January 1, 2016, using the MeSH terms for a variety of STDs and infertility. The search was restricted to human studies...... performed in men and published in English. Studies were included if they contained original data on a possible association or a cause-and-effect relationship between STD and male infertility. Studies were considered only if they included an appropriate control group and/or comprehensive laboratory data. Due...
Sexually Transmitted Diseases on Bipartite Graph
Wen, Luo-Sheng; Zhong, Jiang; Yang, Xiao-Fan
2009-01-01
We study the susceptible-infected-susceptible (SIS) epidemic model on bipartite graph. According to the difference of sex conception in western and oriental nations, we construct the Barabási Albert-Barabási Albert (BA-BA) model and Barabási-Albert Homogeneity (BA-HO) model for sexually transmitted diseases (STDs). Applying the rate equation approach, the positive equilibria of both models are given analytically. We find that the ratio between infected females and infected males is distinctly different in both models and the infected density in the BA-HO model is much less than that in the BA-BA model. These results explain that the countries with small ratio have less infected density than those with large ratio. Our numerical simulations verify these theoretical results.
Sexually Transmitted Diseases on Bipartite Graph
WEN Luo-Sheng; ZHONG Jiang; YANG Xiao-Fan
2009-01-01
We study the susceptible-infected-susceptible (SIS) epidemic model on bipartite graph. According to the dif-ference of sex conception in western and oriental nations, we construct the Barabasi Albert-Barabasi Albert (BA-BA) model and Barabasi-Albert Homogeneity (BA-HO) model for sexually transmitted diseases (STDs). Applying the rate equation approach, the positive equilibria of both models are given analytically. We lind that the ratio between infected females and infected males is distinctly different in both models and the infected den-sity in the BA-HO model is much less than that in the BA-BA model. These results explain that the countries with small ratio have less infected density than those with large ratio. Our numerical simulations verify these theoretical results.
Interviews with candidates for president transmitted
Wilson Gomes
2012-07-01
Full Text Available In election years, television interviews with presidential candidates, broadcast live, i.e. without the use of editing, have become an important genre of journalistic representation in Brazilian political campaigns. These interviews are conducted in network studios by well-known Brazilian news anchors. The fact that these interviews are transmitted directly to the electorate in an unedited form is generally offered as a guarantee of a genuine, authentic portrayal of the candidates themselves. The present work proposes that live network candidate interviews, rather than a means of political presentation on television, are actually an arena in which the institution of journalism attempts to use rhetorical and argumentative means to control the candidates’ discourse without relying on the traditional advantages conferred in daily news coverage.
Polyploidy Induction of Pteroceltis tatarinowii Maxim
Lin ZHANG; Feng WANG; Zhongkui SUN; Cuicui ZHU; Rongwei CHEN
2015-01-01
3%Objective] This study was conducted to obtain tetraploid Pteroceltis tatari-nowi Maxim. with excel ent ornamental traits. [Method] The stem apex growing points of Pteroceltis tatarinowi Maxim. were treated with different concentrations of colchicine solution for different hours to figure out a proper method and obtain poly-ploids. [Result] The most effective induction was obtained by treatment with 0.6%-0.8% colchicine for 72 h with 34.2% mutation rate. Flow cytometry and chromosome observation of the stem apex growing point of P. tatarinowi Maxim. proved that the tetraploid plants were successful y obtained with chromosome number 2n=4x=36. [Conclusion] The result not only fil s the blank of polyploid breeding of P. tatarinowi , but also provides an effective way to broaden the methods of cultivation of fast-growing, high-quality, disease-resilience, new varieties of Pteroceltis.
Quantum theory allows for absolute maximal contextuality
Amaral, Barbara; Cunha, Marcelo Terra; Cabello, Adán
2015-12-01
Contextuality is a fundamental feature of quantum theory and a necessary resource for quantum computation and communication. It is therefore important to investigate how large contextuality can be in quantum theory. Linear contextuality witnesses can be expressed as a sum S of n probabilities, and the independence number α and the Tsirelson-like number ϑ of the corresponding exclusivity graph are, respectively, the maximum of S for noncontextual theories and for the theory under consideration. A theory allows for absolute maximal contextuality if it has scenarios in which ϑ /α approaches n . Here we show that quantum theory allows for absolute maximal contextuality despite what is suggested by the examination of the quantum violations of Bell and noncontextuality inequalities considered in the past. Our proof is not constructive and does not single out explicit scenarios. Nevertheless, we identify scenarios in which quantum theory allows for almost-absolute-maximal contextuality.
The maximal process of nonlinear shot noise
Eliazar, Iddo; Klafter, Joseph
2009-05-01
In the nonlinear shot noise system-model shots’ statistics are governed by general Poisson processes, and shots’ decay-dynamics are governed by general nonlinear differential equations. In this research we consider a nonlinear shot noise system and explore the process tracking, along time, the system’s maximal shot magnitude. This ‘maximal process’ is a stationary Markov process following a decay-surge evolution; it is highly robust, and it is capable of displaying both a wide spectrum of statistical behaviors and a rich variety of random decay-surge sample-path trajectories. A comprehensive analysis of the maximal process is conducted, including its Markovian structure, its decay-surge structure, and its correlation structure. All results are obtained analytically and in closed-form.
Energy Band Calculations for Maximally Even Superlattices
Krantz, Richard; Byrd, Jason
2007-03-01
Superlattices are multiple-well, semiconductor heterostructures that can be described by one-dimensional potential wells separated by potential barriers. We refer to a distribution of wells and barriers based on the theory of maximally even sets as a maximally even superlattice. The prototypical example of a maximally even set is the distribution of white and black keys on a piano keyboard. Black keys may represent wells and the white keys represent barriers. As the number of wells and barriers increase, efficient and stable methods of calculation are necessary to study these structures. We have implemented a finite-element method using the discrete variable representation (FE-DVR) to calculate E versus k for these superlattices. Use of the FE-DVR method greatly reduces the amount of calculation necessary for the eigenvalue problem.
Absence of parasympathetic reactivation after maximal exercise.
de Oliveira, Tiago Peçanha; de Alvarenga Mattos, Raphael; da Silva, Rhenan Bartels Ferreira; Rezende, Rafael Andrade; de Lima, Jorge Roberto Perrout
2013-03-01
The ability of the human organism to recover its autonomic balance soon after physical exercise cessation has an important impact on the individual's health status. Although the dynamics of heart rate recovery after maximal exercise has been studied, little is known about heart rate variability after this type of exercise. The aim of this study is to analyse the dynamics of heart rate and heart rate variability recovery after maximal exercise in healthy young men. Fifteen healthy male subjects (21·7 ± 3·4 years; 24·0 ± 2·1 kg m(-2) ) participated in the study. The experimental protocol consisted of an incremental maximal exercise test on a cycle ergometer, until maximal voluntary exhaustion. After the test, recovery R-R intervals were recorded for 5 min. From the absolute differences between peak heart rate values and the heart rate values at 1 and 5 min of the recovery, the heart rate recovery was calculated. Postexercise heart rate variability was analysed from calculations of the SDNN and RMSSD indexes, in 30-s windows (SDNN(30s) and RMSSD(30s) ) throughout recovery. One and 5 min after maximal exercise cessation, the heart rate recovered 34·7 (±6·6) and 75·5 (±6·1) bpm, respectively. With regard to HRV recovery, while the SDNN(30s) index had a slight increase, RMSSD(30s) index remained totally suppressed throughout the recovery, suggesting an absence of vagal modulation reactivation and, possibly, a discrete sympathetic withdrawal. Therefore, it is possible that the main mechanism associated with the fall of HR after maximal exercise is sympathetic withdrawal or a vagal tone restoration without vagal modulation recovery. © 2012 The Authors Clinical Physiology and Functional Imaging © 2012 Scandinavian Society of Clinical Physiology and Nuclear Medicine.
Radaydeh, Redha Mahmoud
2014-02-01
This paper studies generalized single-stream transmit beamforming employing receive array co-channel interference reduction algorithms under slow and flat fading multiuser wireless systems. The impact of imperfect prediction of channel state information for the desired user spatially uncorrelated transmit channels on the effectiveness of transmit beamforming for different interference reduction techniques is investigated. The case of over-loaded receive array with closely-spaced elements is considered, wherein it can be configured to specified interfering sources. Both dominant interference reduction and adaptive interference reduction techniques for statistically ordered and unordered interferers powers, respectively, are thoroughly studied. The effect of outdated statistical ordering of the interferers powers on the efficiency of dominant interference reduction is studied and then compared against the adaptive interference reduction. For the system models described above, new analytical formulations for the statistics of combined signal-to-interference-plus-noise ratio are presented, from which results for conventional maximum ratio transmission and single-antenna best transmit selection can be directly deduced as limiting cases. These results are then utilized to obtain quantitative measures for various performance metrics. They are also used to compare the achieved performance of various configuration models under consideration. © 1972-2012 IEEE.
Maximizing band gaps in plate structures
Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard
2006-01-01
Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...... periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated...
Maximal and Minimal Congruences on Some Semigroups
Jintana SANWONG; Boorapa SINGHA; R.P.SULLIVAN
2009-01-01
In 2006,Sanwong and Sullivan described the maximal congruences on the semigroup N consisting of all non-negative integers under standard multiplication,and on the semigroup T(X) consisting of all total transformations of an infinite set X under composition. Here,we determine all maximal congruences on the semigroup Zn under multiplication modulo n. And,when Y X,we do the same for the semigroup T(X,Y) consisting of all elements of T(X) whose range is contained in Y. We also characterise the minimal congruences on T(X,Y).
Maximizing oil yields may not optimize economics
1987-03-01
The Los Alamos National Laboratory has used the ASPEN computer code to calculate the economics of different hydroretorting conditions. When the oil yield was maximized and a oil shale plant designed around this process, the costs turned out much higher than expected. However, calculations based on runs of less than maximum yields showed lower cost estimates. It is recommended that future efforts should be concentrated on minimizing production costs rather than maximizing yields. An oil shale plant has been designed around minimum production cost, but has not been able to be tested experimentally.
Maximal Inequalities for Dependent Random Variables
Hoffmann-Jorgensen, Jorgen
2016-01-01
Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X-k. Then a......Maximal inequalities play a crucial role in many probabilistic limit theorem; for instance, the law of large numbers, the law of the iterated logarithm, the martingale limit theorem and the central limit theorem. Let X-1, X-2,... be random variables with partial sums S-k = X-1 + ... + X...
Singularity Structure of Maximally Supersymmetric Scattering Amplitudes
Arkani-Hamed, Nima; Bourjaily, Jacob L.; Cachazo, Freddy
2014-01-01
We present evidence that loop amplitudes in maximally supersymmetric (N=4) Yang-Mills theory (SYM) beyond the planar limit share some of the remarkable structures of the planar theory. In particular, we show that through two loops, the four-particle amplitude in full N=4 SYM has only logarithmic ...... singularities and is free of any poles at infinity—properties closely related to uniform transcendentality and the UV finiteness of the theory. We also briefly comment on implications for maximal (N=8) supergravity theory (SUGRA)....
Blood detection in wireless capsule endoscopy using expectation maximization clustering
Hwang, Sae; Oh, JungHwan; Cox, Jay; Tang, Shou Jiang; Tibbals, Harry F.
2006-03-01
Wireless Capsule Endoscopy (WCE) is a relatively new technology (FDA approved in 2002) allowing doctors to view most of the small intestine. Other endoscopies such as colonoscopy, upper gastrointestinal endoscopy, push enteroscopy, and intraoperative enteroscopy could be used to visualize up to the stomach, duodenum, colon, and terminal ileum, but there existed no method to view most of the small intestine without surgery. With the miniaturization of wireless and camera technologies came the ability to view the entire gestational track with little effort. A tiny disposable video capsule is swallowed, transmitting two images per second to a small data receiver worn by the patient on a belt. During an approximately 8-hour course, over 55,000 images are recorded to a worn device and then downloaded to a computer for later examination. Typically, a medical clinician spends more than two hours to analyze a WCE video. Research has been attempted to automatically find abnormal regions (especially bleeding) to reduce the time needed to analyze the videos. The manufacturers also provide the software tool to detect the bleeding called Suspected Blood Indicator (SBI), but its accuracy is not high enough to replace human examination. It was reported that the sensitivity and the specificity of SBI were about 72% and 85%, respectively. To address this problem, we propose a technique to detect the bleeding regions automatically utilizing the Expectation Maximization (EM) clustering algorithm. Our experimental results indicate that the proposed bleeding detection method achieves 92% and 98% of sensitivity and specificity, respectively.
MULTIPLE TRELLIS CODED ORTHOGONAL TRANSMIT SCHEME FOR MULTIPLE ANTENNA SYSTEMS
无
2006-01-01
In this paper, a novel multiple trellis coded orthogonal transmit scheme is proposed to exploit transmit diversity in fading channels. In this scheme, a unique vector from a set of orthogonal vectors is assigned to each transmit antenna. Each of the output symbols from the multiple trellis encoder is multiplied with one of these orthogonal vectors and transmitted from corresponding transmit antennas. By correlating with corresponding orthogonal vectors, the receiver separates symbols transmitted from different transmit antennas.This scheme can be adopted in coherent/differential systems with any number of transmit antennas. It is shown that the proposed scheme encompasses the conventional trellis coded unitary space-time modulation based on the optimal cyclic group codes as a special case. We also propose two better designs over the conventional trellis coded unitary space-time modulation. The first design uses 8 Phase Shift Keying (8-PSK) constellations instead of 16 Phase Shift Keying (16-PSK) constellations in the conventional trellis coded unitary space-time modulation. As a result, the product distance of this new design is much larger than that of the conventional trellis coded unitary space-time modulation. The second design introduces constellations with multiple levels of amplitudes into the design of the multiple trellis coded orthogonal transmit scheme. For both designs, simulations show that multiple trellis coded orthogonal transmit schemes can achieve better performance than the conventional trellis coded unitary space-time schemes.
Maximizing the Effective Lifetime of Mobile Ad Hoc Networks
Hossain, M. Julius; Dewan, M. Ali Akber; Chae, Oksam
This paper presents a new routing approach to extend the effective lifetime of mobile ad hoc networks (MANET) considering both residual battery energy of the participating nodes and routing cost. As the nodes in ad hoc networks are limited in power, a power failure occurs if a node has insufficient remaining energy to send, receive or forward a message. So, it is important to minimize the energy expenditure as well as to balance the remaining battery power among the nodes. Cost effective routing algorithms attempt to minimize the total power needed to transmit a packet which causes a large number of nodes to loose energy quickly and die. On the other hand, lifetime prediction based routing algorithms try to balance the remaining energies among the nodes in the networks and ignore the transmission cost. These approaches extend the lifetime of first few individual nodes. But as nodes spend more energy for packet transfer, power failures occurs, within short interval resulting more number of total dead node earlier. This reduces the effective lifetime of the network, as at this stage successful communication is not possible due to the lack of forwarding node. The proposed method keeps the transmission power in modest range and at the same time tries to reduce the variance of the residual energy of the nodes more effectively to obtain the highest useful lifetime of the networks in the long run. Nonetheless, movement of nodes frequently creates network topology changes via link breaks and link creation and thus effects on the stability of the network. So, the pattern of the node movement is also incorporated in our route selection procedure.
A dual band wireless power and data telemetry for retinal prosthesis.
Wang, Guoxing; Liu, Wentai; Sivaprakasam, Mohanasankar; Zhou, Mingcui; Weiland, James D; Humayun, Mark S
2006-01-01
Inductive coupling is commonly used for wireless power and data transfer in biomedical telemetry systems. The increasing demand on the performance of medical devices requires high data rate and high power efficiency at the same time. If only one radio frequency carrier is used, it is difficult to achieve both high data rate and high power efficiency due to the competing requirements on carrier frequency and system-Q of the power and data transmission. We propose a dual band telemetry system to implement power and data transmission using different frequencies by allocating lower frequency for power transmission and higher frequency for data transmission. However, the magnetic coupling between the power carrier and data carrier will affect the operation of both links. In this paper, this interference is analyzed and design equations are derived, which are used to design coils to maximize the data signal level received at the implant side. A prototype of dual band telemetry for a retinal prosthetic device has been built and experimental results show that both power and data can be transmitted and high data rate can be achieved without compromising the power transmission efficiency.
Cycle-maximal triangle-free graphs
Durocher, Stephane; Gunderson, David S.; Li, Pak Ching;
2015-01-01
Abstract We conjecture that the balanced complete bipartite graph K ⌊ n / 2 ⌋ , ⌈ n / 2 ⌉ contains more cycles than any other n -vertex triangle-free graph, and we make some progress toward proving this. We give equivalent conditions for cycle-maximal triangle-free graphs; show bounds...
Robust Utility Maximization Under Convex Portfolio Constraints
Matoussi, Anis, E-mail: anis.matoussi@univ-lemans.fr [Université du Maine, Risk and Insurance institut of Le Mans Laboratoire Manceau de Mathématiques (France); Mezghani, Hanen, E-mail: hanen.mezghani@lamsin.rnu.tn; Mnif, Mohamed, E-mail: mohamed.mnif@enit.rnu.tn [University of Tunis El Manar, Laboratoire de Modélisation Mathématique et Numérique dans les Sciences de l’Ingénieur, ENIT (Tunisia)
2015-04-15
We study a robust maximization problem from terminal wealth and consumption under a convex constraints on the portfolio. We state the existence and the uniqueness of the consumption–investment strategy by studying the associated quadratic backward stochastic differential equation. We characterize the optimal control by using the duality method and deriving a dynamic maximum principle.
Maximizing the Motivated Mind for Emergent Giftedness.
Rea, Dan
2001-01-01
This article explains how the theory of the motivated mind conceptualizes the productive interaction of intelligence, creativity, and achievement motivation and how this theory can help educators to maximize students' emergent potential for giftedness. It discusses the integration of cold-order thinking and hot-chaotic thinking into fluid-adaptive…
The Winning Edge: Maximizing Success in College.
Schmitt, David E.
This book offers college students ideas on how to maximize their success in college by examining the personal management techniques a student needs to succeed. Chapters are as follows: "Getting and Staying Motivated"; "Setting Goals and Tapping Your Resources"; "Conquering Time"; "Think Yourself to College Success"; "Understanding and Remembering…
MAXIMAL ELEMENTS AND EQUILIBRIUM OF ABSTRACT ECONOMY
刘心歌; 蔡海涛
2001-01-01
An existence theorem of maximal elements for a new type of preference correspondences which are Qθ-majorized is given. Then some existence theorems of equilibrium for abstract economy and qualitative game in which the constraint or preference correspondences are Qθ-majorized are obtained in locally convex topological vector spaces.
DNA solution of the maximal clique problem.
Ouyang, Q; Kaplan, P D; Liu, S; Libchaber, A
1997-10-17
The maximal clique problem has been solved by means of molecular biology techniques. A pool of DNA molecules corresponding to the total ensemble of six-vertex cliques was built, followed by a series of selection processes. The algorithm is highly parallel and has satisfactory fidelity. This work represents further evidence for the ability of DNA computing to solve NP-complete search problems.
Maximal workload capacity on moving platforms
Heus, R.; Wertheim, A.H.
1996-01-01
Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main
Maximal workload capacity on moving platforms
Heus, R.; Wertheim, A.H.
1996-01-01
Physical tasks on a moving platform required more energy than the same tasks on a non-moving platform. In this study the maximum aerobic performance (defined as V_O2max) of people working on a moving floor was established compared to the maximal aerobic performance on a non-moving floor. The main qu
Maximizing Resource Utilization in Video Streaming Systems
Alsmirat, Mohammad Abdullah
2013-01-01
Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…
Maximizing throughput in an automated test system
朱君
2007-01-01
@@ Overview This guide is collection of whitepapers designed to help you develop test systems that lower your cost, increase your test throughput, and can scale with future requirements. This whitepaper provides strategies for maximizing system throughput. To download the complete developers guide (120 pages), visit ni. com/automatedtest.
The gaugings of maximal D=6 supergravity
Bergshoeff, E.; Samtleben, H.; Sezgin, E.
2008-01-01
We construct the most general gaugings of the maximal D = 6 supergravity. The theory is ( 2, 2) supersymmetric, and possesses an on-shell SO( 5, 5) duality symmetry which plays a key role in determining its couplings. The field content includes 16 vector fields that carry a chiral spinor representat
WEIGHTED BOUNDEDNESS OF A ROUGH MAXIMAL OPERATOR
无
2000-01-01
In this note the authors give the weighted Lp-boundedness fora class of maximal singular integral operators with rough kernel.The result in this note is an improvement and extension ofthe result obtained by Chen and Lin in 1990.
Maximizing the Range of a Projectile.
Brown, Ronald A.
1992-01-01
Discusses solutions to the problem of maximizing the range of a projectile. Presents three references that solve the problem with and without the use of calculus. Offers a fourth solution suitable for introductory physics courses that relies more on trigonometry and the geometry of the problem. (MDH)
Ehrenfest's Lottery--Time and Entropy Maximization
Ashbaugh, Henry S.
2010-01-01
Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…
Testing maximality in muon neutrino flavor mixing
Choubey, S; Choubey, Sandhya; Roy, Probir
2003-01-01
The small difference between the survival probabilities of muon neutrino and antineutrino beams, traveling through earth matter in a long baseline experiment such as MINOS, is shown to be an important measure of any possible deviation from maximality in the flavor mixing of those states.
Average utility maximization: A preference foundation
A.V. Kothiyal (Amit); V. Spinu (Vitalie); P.P. Wakker (Peter)
2014-01-01
textabstractThis paper provides necessary and sufficient preference conditions for average utility maximization over sequences of variable length. We obtain full generality by using a new algebraic technique that exploits the richness structure naturally provided by the variable length of the sequen
On the Hardy-Littlewood maximal theorem
Shinji Yamashita
1982-01-01
Full Text Available The Hardy-Littlewood maximal theorem is extended to functions of class PL in the sense of E. F. Beckenbach and T. Radó, with a more precise expression of the absolute constant in the inequality. As applications we deduce some results on hyperbolic Hardy classes in terms of the non-Euclidean hyperbolic distance in the unit disk.
Maximal Cartel Pricing and Leniency Programs
Houba, H.E.D.; Motchenkova, E.; Wen, Q.
2008-01-01
For a general class of oligopoly models with price competition, we analyze the impact of ex-ante leniency programs in antitrust regulation on the endogenous maximal-sustainable cartel price. This impact depends upon industry characteristics including its cartel culture. Our analysis disentangles the
How to Generate Good Profit Maximization Problems
Davis, Lewis
2014-01-01
In this article, the author considers the merits of two classes of profit maximization problems: those involving perfectly competitive firms with quadratic and cubic cost functions. While relatively easy to develop and solve, problems based on quadratic cost functions are too simple to address a number of important issues, such as the use of…
Ehrenfest's Lottery--Time and Entropy Maximization
Ashbaugh, Henry S.
2010-01-01
Successful teaching of the Second Law of Thermodynamics suffers from limited simple examples linking equilibrium to entropy maximization. I describe a thought experiment connecting entropy to a lottery that mixes marbles amongst a collection of urns. This mixing obeys diffusion-like dynamics. Equilibrium is achieved when the marble distribution is…
Maximally entangled mixed states made easy
Aiello, A; Voigt, D; Woerdman, J P
2006-01-01
We show that, contrarily to a recent claim [M. Ziman and V. Bu\\v{z}ek, Phys. Rev. A. \\textbf{72}, 052325 (2005)], it is possible to achieve maximally entangled mixed states of two qubits from the singlet state via the action of local nonunital quantum channels. Moreover, we present a simple, feasible linear optical implementation of one of such channels.
Maximizing Resource Utilization in Video Streaming Systems
Alsmirat, Mohammad Abdullah
2013-01-01
Video streaming has recently grown dramatically in popularity over the Internet, Cable TV, and wire-less networks. Because of the resource demanding nature of video streaming applications, maximizing resource utilization in any video streaming system is a key factor to increase the scalability and decrease the cost of the system. Resources to…
Maximizing scientific knowledge from randomized clinical trials
Gustafsson, Finn; Atar, Dan; Pitt, Bertram
2010-01-01
Trialists have an ethical and financial responsibility to plan and conduct clinical trials in a manner that will maximize the scientific knowledge gained from the trial. However, the amount of scientific information generated by randomized clinical trials in cardiovascular medicine is highly...
Maximal Heat Generation in Nanoscale Systems
ZHOU Li-Ling; LI Shu-Shen; ZENG Zhao-Yang
2009-01-01
We investigate the heat generation in a nanoscale system coupled to normal leads and find that it is maximal when the average occupation of the electrons in the nanoscale system is 0.5,no matter what mechanism induces the heat generation.
Understanding violations of Gricean maxims in preschoolers and adults.
Okanda, Mako; Asada, Kosuke; Moriguchi, Yusuke; Itakura, Shoji
2015-01-01
This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants' understanding of the following maxims was assessed: be informative (first maxim of quantity), avoid redundancy (second maxim of quantity), be truthful (maxim of quality), be relevant (maxim of relation), avoid ambiguity (second maxim of manner), and be polite (maxim of politeness). Sensitivity to violations of Gricean maxims increased with age: 4-year-olds' understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner), and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.
Understanding Violations of Gricean Maxims in Preschoolers and Adults
Mako eOkanda
2015-07-01
Full Text Available This study used a revised Conversational Violations Test to examine Gricean maxim violations in 4- to 6-year-old Japanese children and adults. Participants’ understanding of the following maxims was assessed: be informative (first maxim of quantity, avoid redundancy (second maxim of quantity, be truthful (maxim of quality, be relevant (maxim of relation, avoid ambiguity (second maxim of manner, and be polite (maxim of politeness. Sensitivity to violations of Gricean maxims increased with age: 4-year-olds’ understanding of maxims was near chance, 5-year-olds understood some maxims (first maxim of quantity and maxims of quality, relation, and manner, and 6-year-olds and adults understood all maxims. Preschoolers acquired the maxim of relation first and had the greatest difficulty understanding the second maxim of quantity. Children and adults differed in their comprehension of the maxim of politeness. The development of the pragmatic understanding of Gricean maxims and implications for the construction of developmental tasks from early childhood to adulthood are discussed.
Equidistant Linear Network Codes with maximal Error-protection from Veronese Varieties
Hansen, Johan P.
2012-01-01
Linear network coding transmits information in terms of a basis of a vector space and the information is received as a basis of a possible altered vectorspace. Ralf Koetter and Frank R. Kschischang in Coding for errors and erasures in random network coding (IEEE Transactions on Information Theory...... construct explicit families of vector-spaces of constant dimension where any pair of distinct vector-spaces are equidistant in the above metric. The parameters of the resulting linear network codes which have maximal error-protection are determined....
Throughput maximization for buffer-aided hybrid half-/full-duplex relaying with self-interference
Khafagy, Mohammad Galal
2015-06-01
In this work, we consider a two-hop cooperative setting where a source communicates with a destination through an intermediate relay node with a buffer. Unlike the existing body of work on buffer-aided half-duplex relaying, we consider a hybrid half-/full-duplex relaying scenario with loopback interference in the full-duplex mode. Depending on the channel outage and buffer states that are assumed available at the transmitters, the source and relay may either transmit simultaneously or revert to orthogonal transmission. Specifically, a joint source/relay scheduling and relaying mode selection mechanism is proposed to maximize the end-to-end throughput. The throughput maximization problem is converted to a linear program where the exact global optimal solution is efficiently obtained via standard convex/linear numerical optimization tools. Finally, the theoretical findings are corroborated with event-based simulations to provide the necessary performance validation.
Hanif, Muhammad
2017-03-20
We present a transmit antenna subset selection scheme for an underlay cognitive system serving multiple secondary receivers. The secondary system employs zero-forcing beamforming to nullify the interference to multiple primary users and eliminate inter-user interference to the secondary users simultaneously. Simulation results show that the proposed scheme achieves near-optimal performance with low computational complexity. Lastly, an optimal power allocation strategy is also introduced to improve the secondary network throughput.
Sexually transmitted diseases in children in India
Dhawan Jyoti
2010-01-01
Full Text Available Sexually transmitted diseases (STDs in children are not uncommon in India, though systematic epidemiological studies to determine the exact prevalence are not available. STDs in children can be acquired via sexual route or, uncommonly, via non-sexual route such as accidental inoculation by a diseased individual. Neonatal infections are almost always acquired intrauterine or during delivery. Voluntary indulgence in sexual activity is also an important factor in acquisition of STDs in childhood. Sexual abuse and sex trafficking remain the important problems in India. Surveys indicate that nearly half of the children are sexually abused. Most at risk children are street-based, homeless or those living in or near brothels. Last two decades have shown an increase in the prevalence of STDs in children, though most of the data is from northern part of the country and from major hospitals. However, due to better availability of antenatal care to majority of women, cases of congenital syphilis have declined consistently over the past two-three decades. Other bacterial STDs are also on decline. On the other hand, viral STDs such as genital herpes and anogenital warts are increasing. This reflects trends of STDs in the adult population. Concomitant HIV infection is uncommon in children. Comprehensive sex education, stringent laws to prevent sex trafficking and child sexual abuse, and antenatal screening of all the women can reduce the prevalence of STDs in children.