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排序方式: 共有1816条查询结果,搜索用时 15 毫秒
11.
This study examines the relationships between care felt and engagement in innovative behaviors at work. We posit that when an individual perceives that coworkers care for him or her (i.e., care felt), this cultivates psychological conditions such as safety, meaningfulness, and availability, which result in a higher level of motivation and by implication engagement in innovative behaviors at work. A sample of 218 employees took part in the assessment of the relationship between the psychological conditions linked to care felt (measured at Time 1) and motivation and engagement in innovative behaviors (measured at Time 2). The results of structural equation modeling (SEM) indicate that care felt is positively linked to psychological conditions. The latter is positively related directly and indirectly (through motivation) to engagement in innovative behaviors. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
12.
Alejandro Israel Bautista-Castillo Luis Abraham Sánchez-Gaspariano Victor Rodolfo González-Díaz Carlos Muñiz-Montero Jose Miguel Rócha Pérez Alejandro Díaz-Sánchez 《Analog Integrated Circuits and Signal Processing》2017,90(2):383-388
The design and simulation of a 2nd harmonic based upconverter is introduced. With the proposed upconverter, it is possible to reach a good noise figure with power and area reduction. The design of the circuit was made with the UMC \(0.18\,\upmu \hbox {m}\) Mixed Mode/RF CMOS technology. However, the design methodology can be extended to a different CMOS process. According to the performance exhibited by the purposed mixer, it may be useful in wideband short-range communication technologies, such as certified wireless USB. 相似文献
13.
The effect of the ionosphere on remote sensing of sea surface salinity from space: absorption and emission at L band 总被引:2,自引:0,他引:2
The purpose of this work is to examine the effects of Faraday rotation and attenuation/emission in the ionosphere in the context of a future remote sensing system in space to measure salinity. Sea surface salinity is important for understanding ocean circulation and for modeling energy exchange with the atmosphere. A passive microwave sensor in space operating near 1.4 GHz (L-band) could provide global coverage and complement in situ arrays being planned to provide subsurface profiles. However, the salinity signal is relatively small and changes along the propagation path can be important sources of error. It is shown that errors due to the ionosphere can be as large as several psu. The dominant source of error is Faraday rotation but emission can be important 相似文献
14.
This article presents an approach to developing high quality tests for switch-level circuits using both current and logic test generation algorithms. Faults that are aborted or undetectable by logic tests may be detected by current tests, or vice versa. An efficient switch level test generation algorithm for generating current and logic tests is introduced. Clear definitions for analyzing the effectiveness of the joint test generation approach are derived. Experimental results are presented for demonstrating high coverage of stuck-at, stuck-on, and stuck-open faults for switch level circuits when both current and logic tests are used.This is expanded version of the work originally presented at the 1991 International Test Conference. 相似文献
15.
An indoor air quality monitoring system helps in the detection and improvement of indoor air quality. The monitoring systems presently available are very expensive. In this paper, we present a low-cost indoor air quality monitoring wireless sensor network system developed using Arduino, XBee modules, and micro gas sensors. The system is capable of collecting six air quality parameters from different locations simultaneously. We have also developed a linear least square estimation-based method for sensor calibration and measurement data conversion. In this paper, we present the detailed design of wireless air quality sensor node and the calibration method. The performance and usefulness of the system are demonstrated by comparing measurement results of our system with a professional-grade air quality measurement device. 相似文献
16.
Marie Held Abraham P. Lee Clive Edwards Dan V. Nicolau 《Microelectronic Engineering》2010,87(5-8):786-789
Although filamentous fungi live in physically and chemically complex natural environments that require optimal survival strategies, both at colony and individual cell level, their growth dynamics are usually studied on homogenous media. This study proposes a new research methodology based on the purposeful design, fabrication and operation of microfluidics structures to examine the temporal and spatial responses of filamentous fungi. Two model fungal strains, the wild type of Neurospora crassa – a commonly used model organisms – and the ro-1 mutant strain of this species impaired in hyphal growth and morphology, have been chosen to demonstrate the potential of this new methodology. Time-lapse observations of both species show that filamentous fungi respond rapidly to the physically microstructured environment without any detectable temporal or spatial adjustment period. Despite their genetic differences, and consequently different growth behaviour, both strains present efficient space-search strategies enabling them to solve the microsized networks successfully and in similar periods, thus demonstrating that the space-searching algorithms are robust and mutation-independent. Additionally, the use of the proposed methodology could put in evidence new biological mechanisms responsible for the apical extension of filamentous fungi, beyond the classical theory based on the central role of Spitzenkörper. 相似文献
17.
Semiconductor testing is aimed at screening fabrication defects that impact expected functionality. While catastrophic defects result in non working devices, parametric faults result in marginalities and are of increasing concern with deep sub-micron process technologies. This work presents a scheme to monitor Circuit-Under-Test (CUT) static bias current to identify catastrophic as well as parametric faults. All circuits require a deterministic amount of DC bias current which may vary outside the specifications when faults exist within the circuit. We propose a compensated current measurement Built-in-Current-Sensor (BICS) scheme, which can be used for sub-system level/circuit-level bias current measurements. The BICS provides accessibility to internal blocks and enables isolated parametric testing. Calibration routine enables process independence and provides robustness. The BICS is compatible with Very-Low-Cost Automatic Test Equipment (VLC-ATE), and can be used for detailed parametric testing in the production environment. 相似文献
18.
Luis Abraham Sánchez Gaspariano Clara Iliana Martínez Gómez José Miguel Rocha Pérez Jesús Ezequiel Molinar Solís Jesús Manuel Muñoz Pacheco Carlos Muñíz Montero Alejandro Díaz Sánchez 《Circuits, Systems, and Signal Processing》2013,32(2):415-431
In this paper, the synthesis, design, and implementation of a programmable phase shifter circuit for sinusoidal signals is presented. The proposed circuit, built-up herein with operational amplifiers (OPAMPs), high precision resistors and low voltage switches, consists of a digitally controlled amplitude attenuator in combination with a single-tone orthogonalizer. Experimental results agree with theoretical background: the attained phase range was 252° in 256 steps with a median step of 0.9°. The inaccuracy of the circuit was determined to be of 0.03 %. Contrary to other OPAMP approaches for sinusoidal signals reported in the literature and based on a first-order all-pass filter structure, the approximation suggested in this work is based on a different concept. The achieved results demonstrate the functionality of the system for the case of a sinusoidal signal with frequency of 1 kHz. Notwithstanding, the proposed architecture can be extended to operate at higher frequencies by using different building blocks with larger bandwidth. Furthermore, it can be extended as well to work out with other periodic input waveforms, like triangular shapes or square waves, with the use of an appropriate orthogonalizer. 相似文献
19.
Sudip Misra P. Venkata Krishna Kiran Isaac Abraham 《Wireless Personal Communications》2011,56(1):55-72
Providing effective medium access for wireless networks is a challenging task. Most of the existing protocols of IEEE 802.11
Medium Access Control (MAC) work towards the goal of achieving effective channel access by developing various backoff procedures.
In this paper, we make an attempt to develop a new medium access protocol named Learning Automata (LA) based Wireless Channel
Reservation (LAWCR). We use an LA approach to implement reservation for channel access for single hop wireless networks. Also,
sequence procedure is used to improve the reservation mechanism. The performance of the proposed LAWCR scheme show significant
improvements over the legacy DCF protocol with respect to important criteria such as the average time spent in the buffer
and the throughput. 相似文献
20.
We present a comprehensive evaluation of the temperature effects on the threshold current and the slope efficiency of 1.55 μm Fabry-Perot ridge-waveguide lasers between 20°C and 120°C. Experimental results are analyzed using the commercial laser simulator PICS3D. The software self-consistently combines two-dimensional carrier transport, heat flux, strained quantum-well gain computation, and optical waveguiding with a longitudinal mode solver. All relevant physical mechanisms are considered, including their dependence on temperature and local carrier density. Careful adjustment of material parameters leads to an excellent agreement between simulation and measurements at all temperatures. At lower temperatures, Auger recombination controls the threshold current and the differential internal efficiency. At high temperatures, the vertical electron leakage from the separate confinement layer mainly limits the laser performance. The increase of internal absorption is less important. However, all these carrier and photon loss enhancements with higher temperature are mainly triggered by the reduction of the optical gain due to wider Fermi spreading of electrons 相似文献