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排序方式: 共有1322条查询结果,搜索用时 15 毫秒
111.
112.
Il Seouk Park Chang Hyun Sohn 《International Communications in Heat and Mass Transfer》2011,38(8):1044-1049
An air core is generated during draining after rotating cylindrical tanks filled with liquid. Air cores have a complex flow structure including rotational motion and a change in the free surface shape. In addition, the generation and extinction of air cores are dependent on the initial rotating speed, the dimensions of the tank, and the liquid materials. This phenomenon is usually detected in various applications for different fields such as the flow in the tundish discharging process of the smelting process, the liquid fuel system of rockets, from the suction of pumps, and so on. In this study, the flow structures including the drain time, the change in the free surface shape, velocity field, and vorticity distributions are numerically and experimentally investigated. Both the numerically and experimentally results were in good agreement with each other with respect to the drain time. 相似文献
113.
Ji Yun Young Sohn Dong Kee Ko Han Seo 《Journal of Mechanical Science and Technology》2022,36(10):5087-5095
Journal of Mechanical Science and Technology - The importance of equipment technology for semiconductor mass production is growing as well as the exponential increase in demand for semiconductors.... 相似文献
114.
Kim Tae Wook Thein Wynn Shin Chang Yell Sohn Uy Dong 《Food science and biotechnology》2021,30(7):979-988
Food Science and Biotechnology - Chronic diabetes mellitus (DM) can cause liver dysfunction and other complications. As Humulus japonicus is known to have anti-inflammatory and antioxidative... 相似文献
115.
Beom-Seok KoJoon-Yong Sohn Young-Chang NhoJunhwa Shin 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2011,269(21):2509-2513
In this study, a versatile monomer, vinylbenzyl chloride (VBC) was radiolytically grafted onto a partially fluorinated ETFE and perfluorinated polymer PFA films. The VBC grafted films were treated with trimethylamine to prepare the alkaline anion exchange membranes (AAEMs). No significant differences in the ion exchange capacities and water uptakes were observed between the ETFE and PFA based AAEMs with similar degree of grafting (DOG). However, the distribution patterns of the graft chains over the cross-section of the ETFE and PFA based AAEMs were found to be quite different; the even distribution was observed from the ETFE based AAEMs while the uneven distribution was observed from the PFA based AAEMs. It was also found that the PFA based AAEMs have the higher ionic conductivity and chemical stability, compared to the ETFE based AAEMs. 相似文献
116.
117.
Sohn Insoo Gupta Someshwar C. 《International Journal of Wireless Information Networks》1999,6(2):59-66
With increasing need for capacity in mobilecellular communications, code division multiple accesshas been viewed as the technique to meet this goal.However, the conventional receiver suffers frommultiuser interference and the near-far effect. Toalleviate this problem, various multiuser receivers havebeen proposed. They have been shown to enhance theperformance of the conventional receiver with respect to capacity and interference rejection. Butthese receivers, intended for Gaussian noise channels,can fail in other environments such as impulsive noiseconditions. A possible solution is to exploit the advantages of neural networks. A neuralnetwork's ability to reject non-Gaussian noise can beutilized to implement multiuser receivers that rejectboth impulsive noise and multiuser interference.Following this logic, this paper considers nonadaptivemultiuser receiver and adaptive multiuser receiver basedon radial basis function neural networks. Simulations ofthese receivers show results that are superior to previously studied multiuser receivers, withrespect to practicality and performance. 相似文献
118.
Ellis R.D. Meitzler T.J. Witus G. Sohn E. Bryk D. Goetz R. Gerhart G.R. 《IEEE transactions on systems, man, and cybernetics. Part A, Systems and humans : a publication of the IEEE Systems, Man, and Cybernetics Society》2000,30(3):336-346
The visual task of detecting an approaching vehicle was modeled with a neurophysiologically motivated computational vision model, the National Automotive Center-visual perception model (NAC-VPM). The scientific literature documenting age-related changes in early vision was reviewed in relationship to the components of the NAC-VPM, and the model was fit to laboratory data from older observers. The model fit the older observers' data adequately, particularly when the data was partitioned into subsets based on viewing conditions. Model fits were compared to calibrations based on younger observers' data. The calibrations based on older observers were substantially different from calibrations based on younger observers, indicating that the model can capture age-related differences in visual perception. When calibrated to the older adults' data, the model successfully predicted conditions under which vehicle detection was particularly difficult for older adults 相似文献
119.
Nitric oxide (NO) has been proposed as an intercellular messenger mediating postsynaptic to presynaptic information transfer in the induction of long-term potentiation. A number of studies support the possible involvement of NO in synaptic plasticity. NO may have a role in synaptogenesis and synaptic plasticity in developing rat brain and may play a fundamental part in the process of regeneration, plasticity, and retargeting of axons following injury. We examined the possible role of NO on plasticity in the rat first somatosensory cortex with [14C]2-deoxyglucose (2-DG) autoradiography in rats treated daily with l-nitroarginine (l-NA) following neonatal unilateral vibrissae deafferentation. After 6 weeks of l-NA treatment, the local cerebral glucose utilization (LCGU) and the spatial extent of the metabolic activation following stimulation of the spared whisker was measured. NOS catalytic activity exhibited significant inhibition throughout the treatment period. Vibrissae deafferentation produced a small but not statistically significant increase of LCGU in the vibrissa activated C3 barrel, and l-NA treatment did not alter the activation of LCGU in the deafferented cortex following whisker stimulation. Additionally, l-NA treatment did not alter the area of metabolic activation on either the non-deafferented side or the deafferented side. Deafferentation produced a 298% increase in the metabolic representation of the spared C3 barrel following stimulation in the saline treated animals, a 257% increase in the chronically l-NA treated animals, and a 256% increase in the short-term treated animals, all with respect to the response in the non-deafferented cortex. Metabolic plasticity in the barrel cortex was not attenuated by l-NA treatment. These results show that nitric oxide does not play a major role on developmental cortical plasticity induced by vibrissae deafferentation in the rat. 相似文献
120.
Hyuek Jae Lee Manjin Sohn Kwangjoon Kim Hae Geun Kim 《Photonics Technology Letters, IEEE》1999,11(2):185-187
By exploiting pump-induced birefringence in addition to cross-gain modulation, we have obtained improved extinction ratio and reduced optical power penalties for a wavelength converter using a semiconductor optical amplifier. In the probe beam wavelength range of 1528-1566 nm, while extinction ratios and power penalties of a conventional wavelength converter are found to be 4.5-9.2 dB and -0.5-2.1 dB, those of the proposed converter are 6.6-10 dB and -0.7-1.0 dB, respectively. The proposed converter shows better performance for all wavelengths in the range examined for both extinction ratio and power penalty. Especially, more improvements have been obtained in the longer wavelength 相似文献