Simultaneous wireless information and power transfer with fixed and adaptive modulation

Activating Wireless Power Transfer (WPT) in Radio-Frequency (RF) to provide on-demand energy supply to widely deployed Internet of Everything devices is a key to the next-generation energy self-sustainable 6G network. However, Simultaneous Wireless Information and Power Transfer (SWIPT) in the same RF bands is challenging. The majority of previous studies compared SWIPT performance to Gaussian signaling with an infinite alphabet, which is impossible to implement in any realistic communication system. In contrast, we study the SWIPT system in a well-known Nakagami-m wireless fading channel using practical modulation techniques with finite alphabet. The attainable rate-energy-reliability tradeoff and the corresponding rationale are revealed for fixed modulation schemes. Furthermore, an adaptive modulation-based transceiver is provided for further expanding the attainable rate-energy-reliability region based on various SWIPT performances of different modulation schemes. The modulation switching thresholds and transmit power allocation at the SWIPT transmitter and the power splitting ratios at the SWIPT receiver are jointly optimized to maximize the attainable spectrum efficiency of wireless information transfer while satisfying the WPT requirement and the instantaneous and average BER constraints. Numerical results demonstrate the SWIPT performance of various fixed modulation schemes in different fading conditions. The advantage of the adaptive modulation-based SWIPT transceiver is validated.     

基于OrCAD/PSpice 9的电路多目标优化设计

提出了一种基于OrCAD／PSpice9的电路多目标优化设计方法，应用该方法可以对各目标参数问的互抗性进行定性分析，并有效地确定他们的权系数，从而实现电路的最佳设计。     

一种新的时空数据折中算法

2006年,Mukhopadhyay和Sarkar提出了一种新的时空数据折中算法,TMTO曲线为T3M7D8=N7,称为MS曲线。文章在MS方法的基础上,通过改变单向函数的使用次序,得到一种新的表结构。利用新的表结构,设计了时空数据折中算法,并得到TMTO曲线DTM2=N2。当D相似文献   

Adult aging effects on semantic and episodic priming in word recognition.

Two experiments compared automatic semantic and episodic priming effects in adult aging. In the 1st experiment, target words were semantically primed; in the 2nd experiment, targets were primed by repetition of semantically unrelated words. Both experiments involved a pronunciation task with response signals at fixed times following target onset. Consequently, priming was measured as improvement in the percentage of correct responses. Priming was also calculated with speed–accuracy measures of intercept and slope. Both types of priming effect were significant in the percentage correct and slope measures, but no age group differences were found. Furthermore, the magnitudes of the priming effects were equivalent. The age-resistant nature of semantic and episodic priming, as well as evidence for a common theoretical mechanism, is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Development of an Engineered Sugar Aminotransferase with Simultaneously Improved Stability and Non-Natural Substrate Activity to Synthesize the Glucosidase Inhibitor Valienamine

Sugar aminotransferases(SATs)catalyze the installation of chiral amines onto specific keto sugars,pro-ducing bioactive amino sugars.Their activity has been utilized in artificial reactions,such as using the SAT WecE to transform valienone into the valuable α-glucosidase inhibitor valienamine.However,the low thermostability and limited activity on non-natural substrates have hindered their applications.Simultaneously improving stability and enzyme activity is particularly challenging owing to the acknowledged inherent trade-off between stability and activity.A customized combinatorial active-site saturation test-iterative saturation mutagenesis(CAST-ISM)strategy was used to simultaneously enhance the stability and activity of WecE toward valienone.Fourteen hotspots related to improving the stability-activity trade-off were identified based on evolutionary conservation and the average mutation folding energy assessment of 57 residues in the active site of WecE.Positive mutagenesis and combinatorial mutations of these specific residues were accomplished via site-directed saturation mutagenesis(SSM)and iterative evolution cycles.Compared with those of the wild-type(WT)WecE,the quadruple mutant M4(Y321F/K209F/V318R/F319V)displayed a 641.49-fold increase in half-life(t1/2)at 40 ℃ and a 31.37-fold increase in activity toward the non-natural substrate valienone.The tri-ple mutant M3(Y321F/K209F/V318R)demonstrated an 83.04-fold increase in(t1/2)at 40 ℃ and a 37.77-fold increase in activity toward valienone.The underlying mechanism was dependent on the strengthened interface interactions and shortened transamination reaction catalytic distance,compared with those of the WT,which improved the stability and activity of the obtained mutants.Thus,we accomplished a general target-oriented strategy for obtaining stable and highly active SATs for artificial amino-sugar biosynthesis applications.     

改善快速晶闸管tq-U_TM折衷关系的研究

分析了影响快速晶闸管tq-U_TM折衷关系的主要因素,简要叙述改善这一关系的有效方法和措施,举例说明相关的设计考虑．实验结果验证了这一设计的合理性。     

Experiences with EDO: An evolutionary database optimizer

In this paper we introduce the database design tool EDO: an Evolutionary Database Optimizer. The term ‘evolutionary’ refers to a basic feature of the tool. After generating an initial pool of preliminary internal representations for a given conceptual data model, EDO allows a database designer to activate evolution strategies, modifying the preliminary internal representations into more desirable ones.

The quality of the internal representations found as yet is used to perform a guided walk through the solution space of alternative internal representations for the conceptual model under consideration. This quality (called fitness) takes into account the expected storage space and the expected average response time of a candidate internal representation.     

Assessing two new wearable input paradigms: The Finger-Joint-Gesture palm-keypad glove and the invisible phone clock

Text and digit entry speed of two wearable one-handed input paradigms, the Finger-Joint-Gesture palm-keypad glove and the Invisible Phone Clock, were benchmarked against traditional one-handed cellular phone keypad input in a repeated-measurement design employing 18 subjects using a 9-word sentence. No significant difference in error-corrected text entry speed (5.3 ec-wpm) was found. Digit entry speed was significantly faster (8.3 ec-wpm) and differed significantly between input paradigms. Furthermore, digit entry was fastest for the traditional cellular phone keypad and slowest for the Invisible Clock keypad. A prediction model based on Fitts' law slightly overestimated text entry speed for novice users. Another prediction model, where each movement time between successive keys was corrected for key repeat time for each specific input paradigm, predicted the experimental results more accurately. Thirteen of the subjects ranked the Invisible Phone Clock as 1^st choice. The subjects' mapping of the Ericsson cellular phone functions (YES, CLR, NO, <,> and Address Book) was not according to the designer's model, partly due to functional fixedness. The input paradigms could be suitable candidates for new fragmentised interfaces where wearability is the key issue.