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71.
Mihajlo C. Stefanovic Jelena A. Anastasov Aleksandra M. Cvetkovic Goran T. Djordjevic 《Wireless Communications and Mobile Computing》2015,15(18):2141-2149
The outage performance of the amplify‐and‐forward relaying strategies over mutually uncorrelated extended generalized‐K fading channels is addressed in this paper. The attention is dedicated to the analyses of the noise‐limited and also interference‐limited environment. The new analytical expression for outage probability of observed relaying system in the presence of thermal noise is derived using the method for approximating equivalent signal‐to‐noise ratio. In addition, the outage performance is studied for the dual‐hop system when only the single dominant co‐channel interference is inherent at the relay and destination node. The correctness of the proposed mathematical derivations is verified by simulations. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
72.
As technology scales toward deep submicron, the integration of complete system-on-chip (SoC) designs consisting of large number of Intellectual Property (IP) blocks (cores) on the same silicon die is becoming technically feasible. Until recently, the design-space exploration for SoCs has been mainly focused on the computational aspects of the problem. However, as the number of IP blocks on a single chip and their performance continue to increase, a shift from computation-based to communication-based designs becomes mandatory. As a result, the communication architecture plays a major role in the area, performance and energy consumption of the overall systems [Pasricha S, Dutt N. On-chip communication architectures: system on chip interconnect. Amsterdam: Elsevier Inc.; 2008, Kim J, Verbauwhede I, Chang MCF. Design of an interconnect architecture and signaling technology for parallelism in communication. IEEE Trans VLSI Syst 2007;15(8):881-94].This article presents a structure of a wrapper as a component of Code Division Multiple Access, CDMA, based shared bus architecture in a SoC. Two types of wrappers can be identified, master and slave. A master wrapper is located between the arbiter and CDMA coded physical interconnect, while a slave connects the CDMA coded bus with memory/peripheral module. In the proposal, only bus lines that carry address and data signals are CDMA coded. We implemented a pair of master-slave wrapper described in VHDL and confirmed its functionality using testbenches. Also we synthesized wrappers using a Xilinx Spartan and Virtex devices to determine resource requirements in respect to a number of equivalent gates, communication bandwidth, latency and power consumption. Specifically we involved a Design_Quality, DQ, metric for wrapper performance evaluation. A pair of master-slave wrapper seems to occupy appropriate space, in average 2000 equivalent gates, considering CPU cost of about 30,000 gates, what is less than 8% of hardware overhead per CPU. We also present experimental results which show that benefits of involving CDMA coding relates both to decreasing a number of bus lines and accomplishing simultaneous multiple master-slave connections at relatively low-power consumption and high communication bandwidth. Convenient range indices RW and RR to determine data transfer rate for Write and Read operations in multiprocessor bus systems that use TDMA and CDMA data transfer techniques. The obtained results show that increased data transfer latencies involved by CDMA data transfer are compensated by simultaneous master-slave transfers. 相似文献
73.
The complete structure of an AGV control system is described in the first part of this paper. The AGV control system is hierarchical and consists of five levels. The structure of one level does not depend on the structures of the other levels. This means that the control system depends on the design of the AGV at the lowest level only, at the actuator servo-control level and its coordination in realizing AGV primitive functions.The second part of the paper describes rules applicable to AGV steering. The structure of these rules depends on two groups of factors. The first group is dependent on information groups fed to the AGV processor by the position sensor. The second group of factors represents aims and conditions and AGV steering such as positioning accuracy, positioning time, allowed room for maneuver, the shape of the given trajectory, etc. The AGV steering rules contain sequences of primitive functions. These primitive functions are of such types as “turn left”, “straighten” (correct), “go straight on”, etc. Trajectory, as one of the basic factors, is defined at the level of controlling an elementary movement. The term “to control an elementary movement” means to select a transport road throughout the transport network and to code it using “elementary movement” such as “go straight” (relating to road section), “turn left” (relating to turning at a crossroad) etc.The results of the AGV steering simulation are presented in the third part of the paper. An exact kinematic AGV model used for stimulating control models is also presented. 相似文献
74.
MS Treuth GR Hunter T Kekes-Szabo RL Weinsier MI Goran L Berland 《Canadian Metallurgical Quarterly》1995,78(4):1425-1431
The purpose of this study was to examine the effects of a total body strength-training program on changes in total and regional body composition, in particular intra-abdominal adipose tissue (IAAT), in older women. Fourteen healthy older women (mean age 67 +/- 1 yr) exercised 3 times/wk for 16 wk. Strength was assessed by one-repetition maximum tests, with training intensity gradually increased to approximately 67% of one repetition maximum. Body composition was measured by hydrodensitometry and regional body composition was measured by computed tomography. Strength was significantly increased in the upper (51%) and lower body (65%). There was no significant change in body weight (64.4 +/- 2.7 vs. 64.2 +/- 2.7 kg), total body fat (38.7 +/- 1.4 vs. 38.0 +/- 1.6%) or fat-free mass (39.7 +/- 1.0 vs. 40.0 +/- 0.9 kg). However, after ST, there were significant reductions in IAAT (143.9 +/- 13.3 vs. 130.0 +/- 12.4 cm2), the IAAT-to-subcutaneous adipose tissue ratio (0.48 +/- 0.04 vs. 0.44 +/- 0.04), and midthigh subcutaneous adipose tissue (141.7 +/- 11.5 vs. 133.6 +/- 10.8 cm2) and an increase in midthigh muscle (52.9 +/- 2.6 vs. 58.0 +/- 2.0 cm2) (all P < 0.05). In conclusion, significant reductions in IAAT and an increase in strength and muscle area were observed after a strength-training program in healthy older women. These changes may be important in preventing the negative health outcomes associated with the age-related increase in intra-abdominal obesity. 相似文献
75.
Void-free Au-Sn eutectic bonding of GaAs dice and its characterization using scanning acoustic microscopy 总被引:1,自引:0,他引:1
A new technique to produce perfect bonding between GaAs dice and alumina substrates is reported. Utilizing this technique,
void-free bondings have been achieved consistently. The quality of the bonded devices is confirmed by a Scanning Acoustic
Microscope (SAM) having a spatial resolution of 25 μm. Thermal cycling between -25° C and 125° C, and thermal shock between
-196° C and 135° C, have been used to assess the reliability of the specimens. The SAM was used to study the variation of
the bonds in the tests. After the tests, the bonds show no sign of degradation and the GaAs dice did not crack. Shear test
has also been performed. All the well bonded specimens passed the shear test. The shear strength correlated very well with
the SAM images of the specimens taken before the test. 相似文献
76.
Relatives of 88 clients enrolled in a postacute rehabilitation program for the treatment of traumatic brain injury completed Section 1 of the Katz Adjustment Scale (KAS-R1). The items were subjected to a principal component analysis, which yielded 10 statistically significant component groups. Internal consistency as determined by Cronbach alpha ranged from 0.78 to 0.94. Moderate correlations were observed between several component groups, suggesting some overlap in components derived. Results suggest that the 127 items of the KAS-R1 form component groups that may represent categorically differentiated behavioral symptoms. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
77.
Leptin has been hypothesized to play an important role in energy balance by affecting both energy intake and energy expenditure. The purpose of our study was to determine the relationship between fasting serum leptin concentrations and measures of energy expenditure in prepubertal children. We measured total energy expenditure (TEE; by the doubly labeled water technique), resting energy expenditure (REE; after an overnight fast), activity energy expenditure (AEE; TEE-REE), body composition (by dual energy x-ray absorptiometry), and fasting serum leptin concentration (by RIA) in 76 children. Simple correlations showed that all measures of energy expenditure (TEE, REE, and AEE) were positively related to the serum leptin concentration (r = 0.50, P < 0.001; r = 0.45, P < 0.001; and r = 0.30, P < 0.01, respectively). However, after adjusting for body composition (fat-free mass and fat mass), gender, and ethnicity, serum leptin concentrations were not related to any measure of energy expenditure (TEE, P = 0.61; REE, P = 0.97; AEE, P = 0.65). These latter findings were further confirmed using structural equation models with leptin and energy expenditure as dependent variables, and fat-free mass and fat mass as independent variables. Results from these models showed no direct effect of leptin and no indirect effect of fat mass (through leptin) on any measure of energy expenditure, when a path between fat mass and energy expenditure was present in the model. Thus, our data do not support the hypothesis that the serum leptin concentration (independent of fat mass) is related to measures of energy expenditure in children. 相似文献
78.
Varela Maria L. R. Putnik Goran D. Manupati Vijay K. Rajyalakshmi Gadhamsetty Trojanowska Justyna Machado José 《Wireless Networks》2021,27(3):1587-1599
Wireless Networks - Integrated process planning and scheduling in networked manufacturing systems plays a crucial role nowadays and in the forthcoming context of Industry 4.0 to enable effective... 相似文献
79.
Zoran Jurkovic Goran Cukor Miran Brezocnik Tomislav Brajkovic 《Journal of Intelligent Manufacturing》2018,29(8):1683-1693
Support vector machines are arguably one of the most successful methods for data classification, but when using them in regression problems, literature suggests that their performance is no longer state-of-the-art. This paper compares performances of three machine learning methods for the prediction of independent output cutting parameters in a high speed turning process. Observed parameters were the surface roughness (Ra), cutting force \((F_{c})\), and tool lifetime (T). For the modelling, support vector regression (SVR), polynomial (quadratic) regression, and artificial neural network (ANN) were used. In this research, polynomial regression has outperformed SVR and ANN in the case of \(F_{c}\) and Ra prediction, while ANN had the best performance in the case of T, but also the worst performance in the case of \(F_{c}\) and Ra. The study has also shown that in SVR, the polynomial kernel has outperformed linear kernel and RBF kernel. In addition, there was no significant difference in performance between SVR and polynomial regression for prediction of all three output machining parameters. 相似文献
80.
Christopher J. Ferguson John ColwellBoris Mla?i? Goran MilasIgor Miklouši? 《Computers in human behavior》2011,27(3):1195-1200
The issue of potential media effects on psychological health of youth and young adults has been debated for decades. Research on media effects has not always been consistent. One issue that has been raised regards whether the relatively modest media effects found in some research might be explained through mediating personality variables. This hypothesis was examined in three samples of young adults: Mexican-Americans (n = 232), Croatians (n = 455) and English (n = 150). Results indicated that trait aggression was a consistent predictor of both violent crimes and depression across samples. General personality variables were less consistent predictors of violence, although neuroticism consistently predicted depression across samples. Media violence exposure did not predict negative outcomes except among Croatians for whom exposure to violent video games predicted fewer violent crimes, and exposure to television violence predicted increased violent crimes. 相似文献