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排序方式: 共有621条查询结果,搜索用时 15 毫秒
1.
Kalai Selvan Ramalingam Karmegam Karuppiah Shiamala Devi Ramaiya Vivien How Enoch Kumar Perimal Hassan Sadeghi Naeini Sivasankar Sambasivam Kulanthayan KC Mani 《人机工程学与制造业中的人性因素》2019,29(5):426-434
Many occupations require workers to stand for long periods of time without proper interventions, which causes discomfort in the back and lower limbs. Therefore, this study aims to assess the effectiveness in alleviating body muscle discomfort during prolonged standing through the use of a calf massager. This study was conducted among male workers at a manufacturer with production line workers and the list was obtained from the HR Department and simple random sampling was done by number categorization. A total of 100 respondents (50 respondents for both the control and the experimental groups) participated in this study. The experiment took place in a room with a similar setup for the production line. Each respondent was requested to perform the simulated task for 2 hr. For the experimental group, the calf massager was turned on every 15 min. At every 15‐min interval after turning on the calf massager, respondents from both groups were required to evaluate their discomfort level on a Borg's scale CR‐10 questionnaire. The results showed that the level of body discomfort among respondents in the experimental group reduced (20–30%) compared with that of the control group. Multivariate analysis results revealed that the discomfort rating for the lower back, knees, thighs, calves, and feet was significantly lower (p < .05) among the experimental group compared with the control group. For lower body parts, the lower back region was statistically significant (p < .05) at the 90th, 105th, and 120th min; the thigh region was statistically significant (p < .05) at the 120th min; the knee region was statistically significant (p < .05) at the 105th and 120th min; the calf region was statistically significant (p < .05) at all minute intervals except the 15th and 45th min, while the feet region, was statistically significant at the 105th and 120th min. Therefore, this study indicates that calf massage treatment is capable of reducing body muscle discomfort during prolonged standing and highlights the significance of calf massage. 相似文献
2.
High slew-rate CMOS operational amplifier 总被引:1,自引:0,他引:1
A 0.8 /spl mu/m CMOS operational amplifier configuration with a slew rate in excess of 2 V/ns and a unity gain bandwidth of 55 MHz with a load capacitance of 15 pF is proposed. This employs a dynamic technique that turns on a large current source when the rate of change of input is larger than a pre-decided value. 相似文献
3.
M.S. Detrick G.N. Washington V.V. Subramaniam 《Mechatronics, IEEE/ASME Transactions on》2003,8(1):45-55
In this work, the diamond deposited by hot filament chemical vapor deposition (CVD) is polished using an atmospheric pressure plasma. In order to position the film relative to the plasma, a microactuator system is designed using a stack of domed piezoelectric actuators. A dynamic model based on the physical system is developed and the model parameters are measured experimentally. A system based on laser triangulation is used to measure the position of the diamond film relative to the plasma. Control techniques are used to reduce the oscillations during actuation and to eliminate the steady state positioning error. With the application of feedback control, the overshoot is reduced to 2% and the settling time is reduced to 0.3 s. A preliminary set of experiments is performed to relate process parameters to the final surface roughness of the diamond film. The parameters studied include the film's time of exposure to the plasma, the height of the film relative to the plasma, and the distance from the film to the center of the plasma. It is found that the optimum exposure time is 15 min and the reduction of surface roughness is greatest when the distance between the film and the plasma is at a minimum. The best results are obtained when the top of the film is even in elevation with the tip of the top electrode. The diamond film is translated laterally along the plasma. When feedback control is not used, there is no change in the surface roughness. With feedback control implemented, the surface roughness of the diamond film is reduced by 33%. 相似文献
4.
AH Lauber TJ Barrett M Subramaniam M Schuchard TC Spelsberg 《Canadian Metallurgical Quarterly》1997,272(39):24657-24665
The receptor-binding factor (RBF) for the avian oviduct progesterone (Pg) receptor (PR) has previously been shown to be a unique 10-kDa nuclear matrix protein that generates high affinity PR-binding sites on avian DNA. This paper describes the use of Southwestern blot and DNA gel shift analyses with RBF protein to identify a minimal 54-base pair RBF-binding element in the matrix-associated region (MAR) of the Pg-regulated c-myc gene promoter. This element contains a 5'-GC-rich domain and a 3'-AT-rich domain, the latter of which has a homopurine/homopyrimidine structure. The gel shift assays required the generation of an RBF-maltose fusion protein (RBF-MBP), which specifically binds this element and is supershifted when the anti-RBF polyclonal antibody is added. Computer analysis of the full-length amino acid sequence for RBF predicts a DNA-binding motif involving a beta-sheet structure at the N-terminal domain. Southern blot analyses using nuclear matrix DNA suggests that there are dual MAR sites in the c-myc promoter, which flank an intervening domain containing the RBF element. The co-transfection of this MAR sequence, containing the RBF element and cloned into a luciferase reporter vector, together with an RBF expression vector construct, into steroid treated human MCF-7 cells, results in a decrease of the c-myc promoter activity relative to control transfections containing only the parent vector of the RBF expression construct. These data suggest that a unique chromatin/nuclear matrix structure, composed of the RBF-DNA element complex which is flanked by nuclear matrix attachment sites, serves to bind the PR and repress the c-myc promoter. 相似文献
5.
Rett syndrome (RS), a neurodevelopmental disorder of unknown etiology occurring almost exclusively in females, is characterized by autistic-like behavior, motor dysfunction, loss of language skills, dementia, and microcephaly. This study is a follow-up and extension of a previously reported neuroimaging study of patients with RS. We replicated previously reported findings with a larger patient population, and the volumetric MRI analysis was extended to include an analysis of neuroanatomy of the posterior fossa. Twenty girls with RS were compared with individually age- and gender-matched normal controls. Patients with RS showed global reduction in gray- and white-matter volumes. The prefrontal, posterior-frontal, and anterior-temporal regions showed the largest bilateral decrease in gray-matter volume, whereas white-matter volume was uniformly reduced throughout the brain. We found confirmation for the preferential reduction in caudate nucleus volume. However, we observed no preferential reduction in midbrain volume despite a preferential reduction in the midsagittal area of this region. We also present an individual case comparison between monozygotic twins discordant for RS. 相似文献
6.
Sankaranarayanan S. Subramaniam S. 《Selected Areas in Communications, IEEE Journal on》2003,21(9):1399-1413
Multicasting is becoming increasingly important in today's networks. In optical networks, optical splitters facilitate the multicasting of optical signals. By eliminating the transmission of redundant traffic over certain links, multicasting can improve network performance. However, in a wavelength-division multiplexed (WDM) optical network, the lack of wavelength conversion necessitates the establishment of a single multicast circuit (light-tree) on a single wavelength. On the other hand, establishing several unicast connections (lightpaths) to satisfy a multicast request, while requiring more capacity, is less constrained in terms of wavelength assignment. The objective of the paper is to evaluate the tradeoff between capacity and wavelength continuity in the context of optical multicasting. To this end, we develop accurate analytical models with moderate complexity for computing the blocking probability of multicast requests realized using light-trees, lightpaths, and combinations of light-trees and lightpaths. Numerical results indicate that a suitable combination of light-trees and lightpaths performs best when no wavelength conversion is present. 相似文献
7.
Landmarks needed for detecting dental abnormalities in cephalometric analysis were selected from the digital image, and the angle values needed for dental analysis were calculated and stored in a database which is used for developing training dataset. Principal component analysis was applied for dimension reduction to get the desired feature vectors which are trained and tested using support vector machine and proximal support vector machine classifier to detect the dental abnormalities, the performance of the classifiers were also compared. 相似文献
8.
Hai-Feng Guo Mahadevan Subramaniam 《International Journal on Software Tools for Technology Transfer (STTT)》2014,16(4):437-455
A novel, model-based test case generation approach for validating reactive systems, especially those supporting richly structured data inputs and/or interactions, is presented. Given an executable system model and an extended symbolic grammar specifying plausible system inputs, the approach performs a model-based simulation to (i) ensure the consistency of the model with respect to the specified inputs, and (ii) generate corresponding test cases for validating the system. The model-based simulation produces a state transition diagram (STD) automatically justifying the model runtime behaviors within the test case coverage. The STD can further be transformed to produce an evolved symbolic grammar, which can then be used to incrementally generate a refined set of test cases. As a case study, we present a live sequence chart (LSC) model-based test generator, named LCT in short, for LSC simulation and consistency testing. The evolved symbolic grammar produced by the simulator can either be used to generate practical test cases for software testing, or be further refined by applying our model-based test generation approach again with additional test coverage criteria. We further show that LSCs can also be used to specify and test certain temporal system properties during the model simulation. Their satisfaction, reflected in the STD, can either be served as a directive for selective test generation, or a basis for further temporal property model checking. 相似文献
9.
Thermal and flow properties of unrefined oils from the heads of red or pink salmon were evaluated. Major thermal degradation
of the salmon oils occurred between 200 and 450°C. Red and pink salmon oils were completely decomposed at 533 and 668°C, respectively.
The phase transition of salmon oils occurred over a wide range of temperatures. The melting points of −69.6 to −0.36°C and
−64.7 to 20.8°C were observed for red and pink salmon oils, respectively. The enthalpy was 40 j/g for red salmon oil and 39
j/g for pink salmon oil. Specific heat capacity ranges of 0.8 to 1.6 and 1.3 to 2.3 j/g/°C were observed for red and pink
salmon oils, respectively. Both salmon oils exhibited Newtonian flow behavior. Red salmon oil required higher magnitudes of
energy (kj·mol−1) to flow than pink salmon oil. The viscosity of salmon oils was temperature-dependent and could be predicted by the Arrhenius
equation. 相似文献
10.
Ramalingam Shanmugam 《通讯和计算机》2013,(6):743-747
In this article, new probabilistic health-informatics indices connecting probabilities: Pr(A),Pr(B),Pr(A IB) and P r(A ]B-) are discovered, where .4 and B denote respectively the "ability of a hospital to treat anthrax patients" and "whether a hospital drilled to be prepared to deal with an adverse bioterrorism". These probabilistic informatics are not seen in any textbooks or journal articles and yet, they are too valuable to be unnoticed to comprehend the hospitals' preparedness to treat anthrax patients in an outbreak of bioterrorism. A demonstration of this new probabilistic informatics is made in this article with the data in the U.S. Government's General Accounting Office's report GA0-03-924. Via this example, this article advocates the importance of the above mentioned probabilistic-informatics for health professionals to understand and act swiftly to deal with public health emergencies. 相似文献