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991.
Pyung-Hoi Koo Jaejin Jang Jungdae Suh 《International Journal of Flexible Manufacturing Systems》2004,16(3):211-228
As manufacturing systems have grown in size and complexity, material flow control has become one of the key issues for system
efficiency, and determination of the number of vehicles required is an important issue in the design of the AGV (automatic
guided vehicle) systems for automated material flow control. In an AGV system, a part issues a delivery request for its transportation,
and then an empty vehicle is assigned based on a pre-determined vehicle selection rule and provides delivery service.
This research presents a fleet sizing procedure for an AGV system with multiple pickup and delivery stations. A queueing model
is used to estimate part waiting times. The fleet sizing procedure estimates the minimum number of vehicles needed to ensure
a predefined part waiting time limit. While most stochastic models assume first-come-first-served or random vehicle selection
rules for the selection of an empty vehicle, this model considers such additional rules as the nearest vehicle selection rule,
which is the most popular among all vehicle selection rules. The performance of the proposed model is examined through computational
experiments.
This work was supported by Korea Research Foundation Grant (KRF-2003-042-D20136). 相似文献
992.
Jang ZH Suh BJ Corti M Cattaneo L Hajny D Borsa F Luban M 《The Review of scientific instruments》2008,79(4):046101
We have developed a nonconventional broadband electron spin resonance (ESR) spectrometer operating continuously in the frequency range from 0.5 to 9 GHz. Dual antenna structure and the microwave absorbing environment differentiate the setup from the conventional one and enable broadband operation with any combination of frequency or magnetic field modulation and frequency or magnetic field sweeping. Its performance has been tested with the measurements on a 1,1-diphenyl-2-picrylhydrazyl (DPPH) sample and with the measurements on the single molecular magnet, V6, in solid state at low temperature. 相似文献
993.
In this paper, making the best use of the features of the electro-rheological (ER) valve, a two-port pressure control valve
using ER fluids is proposed and manufactured. The ER-Valve characteristics are evaluated by changing the intensity of the
electric field and the number of electrode. As only with electrical signal change to the ER-Valve in which ER fluid flowing,
ER fluid flow is controlled, so development of simple ER-Valves have been tried. The ER-Valves and pressure drop check method
are considered to be applied to the fluid power industry. Using the manufactured pressure control valve, a one-link manipulator
with FHA (Flexible Hydraulic Actuator) is driven. As a result, it is experimentally confirmed that the pressure control valve
using ER fluids is applicable to use in driving actuator. If it applies characteristics of the ER fluids, it will be able
to apply in the control system for the ER Valve which occurs from industrial controller. After having durability test, shear
stress increased regularly because of starch particles crushed by pump and particle size that was almost the same. Moreover,
Ra of copper electrode increased about 1.56 times rather than before those of performing durability test, and Rz increased
about 2.2 times. 相似文献
994.
S. Tajima R. Hauff W. -J. Jang A. Rykov Y. Sato I. Terasaki 《Journal of Low Temperature Physics》1996,105(3-4):743-748
The Zn-substitution effects on the c-axis optical spectra have been investigated for highly oxygenated YBa2 Cu3Oy crystals with y = 6.88 – 6.92. In the normal state, the Zn-substitution does not affect the high frequency conductivity but changes the -dependence of the scattering rate at low frequencies, leading to the increase in the dc resistivity in the c-direction. In the superconducting state, we observed a pronounced effect of Zn-substitution that a large number of unpaired carriers form a Drude-like absorption band within the gap, keeping the maximum gap amplitude unchanged. The missing area which gives the superfluid density is found to correlate with Tc. 相似文献
995.
Sehyun Lee Jae Young Jung Injoon Jang Daeil Choi Myeong Jae Lee Dong Wook Lee Jue-Hyuk Jang Jeong Hee Lee Haneul Jin Kyungmin Im Eungjun Lee Seung-hoon Kim Nam Dong Kim Soo-Hyoung Lee Yun Sik Kang Hee-Young Park Dongwon Chun Hyung Chul Ham Kug-Seung Lee Docheon Ahn Pil Kim Sung Jong Yoo 《Advanced functional materials》2021,31(16):2009241
Among the Pt group metals, Pd has been considered the most efficient for application in electrocatalysts as an alternative to Pt. Despite the comparable electrochemical activities of Pd and Pd-metal alloys, they are vulnerable to liquid acidic electrolytes, leading to degradation of catalytic activity. Pd–Ni alloys have been used to enhance catalytic activity because the electronic structure of Pd can be easily changed by adding Ni. In other studies, N atoms have been introduced for more stable M–Ni catalysts by inducing the formation of Ni4N species; however, the structural analysis and the role of nitrogen have not been fully understood yet. Herein, the Pd–Ni alloy nitride with a unique crystal structure shows a promising catalytic activity for oxygen reduction reaction (ORR). The nitride PdNi nanoparticles have a novel monolithic antiperovskite structure of chemical formula (PdxNi1−x)NNi3. The unique antiperovskite crystal (PdxNi1−x)NNi3 possesses superior ORR activity and stability, originating from the downshifted d-band center of the monolayer Pd/antiperovskite surface and the lower formation energy of the antiperovskite core nanocrystal. Consequently, (PdxNi1−x)NNi3, as a Pt-free Pd-based electrocatalyst, overcomes the stability issue of Pd under acidic conditions by achieving 99-times higher mass activity than commercial Pd/C, as shown by the durability test. 相似文献
996.
Trinh Thi Ly Jungmin Park Kyoo Kim Hyo-Bin Ahn Nyun Jong Lee Kwangsu Kim Tae-Eon Park Ganbat Duvjir Nguyen Huu Lam Kyuha Jang Chun-Yeol You Younghun Jo Se Kwon Kim Changgu Lee Sanghoon Kim Jungdae Kim 《Advanced functional materials》2021,31(17):2009758
Microscopic structures and magnetic properties are investigated for Fe5−xGeTe2 single crystal, recently discovered as a promising van der Waals (vdW) ferromagnet. An Fe atom (Fe(1)) located in the outermost Fe5Ge sublayer has two possible split-sites which are either above or below the Ge atom. Scanning tunneling microscopy shows √3 × √3 superstructures which are attributed to the ordering of Fe(1) layer. The √3 × √3 superstructures have two different phases due to the symmetry of Fe(1) ordering. Intriguingly, the observed √3 × √3 ordering breaks the inversion symmetry of crystal, resulting in substantial antisymmetric exchange interaction. The temperature dependence of magnetization reveals a sharp magnetic anomaly suggesting helical magnetism of the Fe5−xGeTe2 due to its non-centrosymmetricity. Analytical study also supports that the observed ordering can give rise to the helimagnetism. The work will provide essential information to understand the complex magnetic properties and the origin of the new vdW ferromagnet, Fe5−xGeTe2 for future topology-based spin devices. 相似文献
997.
Kang Won Lee Woojong Lim Min Soo Jeon Hanmin Jang Jehwan Hwang Chi Hwan Lee Dong Rip Kim 《Advanced functional materials》2022,32(1):2105882
The study of transparent daytime radiative cooling with no additional energy consumption is a promising area of research. Its applications include solar cells and building and automobile windows that are prone to heating issues. Ubiquitous applications necessitate the development of metamaterials with high mechanical flexibility in a scalable manner while overcoming translucence. In this study, visibly clear and flexible radiative cooling metamaterials have been developed using a newly designed optical modulator filled into randomly distributed silica aerogel microparticles in a silicone elastomer. The optical modulator effectively suppresses visible light scattering, thus enabling higher loading of silica aerogel microparticles while securing visible clarity. The significant suppression of the rise in temperature by the metamaterial is verified using both indoor and outdoor experiments. The visibly clear metamaterials deployed in solar cells and windows can effectively suppress the rise in temperature under solar irradiation, thereby mitigating the performance degradation of solar cells by heating issues and suppressing the rise in temperature of indoor air. 相似文献
998.
Virtual Reality - With the rapid developments and improvements in mobile technologies, mobile devices have become one of the primary interfaces of augmented reality technologies. In this study, we... 相似文献
999.
T. S. Jang 《Journal of scientific computing》2018,74(3):1504-1532
A fundamental question in computational nonlinear partial differential equations is raised to discover if one could construct a functional iterative algorithm for the regularized long-wave (RLW) equation (or the Benjamin–Bona–Mahony equation) based on an integral equation formalism? Here, the RLW equation is a third-order nonlinear partial differential equation, describing physically nonlinear dispersive waves in shallow water. For the question, the concept of pseudo-parameter, suggested by Jang (Commun Nonlinear Sci Numer Simul 43:118–138, 2017), is introduced and incorporated into the RLW equation. Thereby, dual nonlinear integral equations of second kind involving the parameter are formulated. The application of the fixed point theorem to the integral equations results in a new (semi-analytic and derivative-free) functional iteration algorithm (as required). The new algorithm allows the exploration of new regimes of pseudo-parameters, so that it can be valid for a much wider range (in the complex plane) of pseudo-parameter values than that of Jang (2017). Being fairly simple (or straightforward), the iteration algorithm is found to be not only stable but accurate. Specifically, a numerical experiment on a solitary wave is performed on the convergence and accuracy of the iteration for various complex values of the pseudo-parameters, further providing the regions of convergence subject to some constraints in the complex plane. Moreover, the algorithm yields a particularly relevant physical investigation of the nonlinear behavior near the front of a slowly varying wave train, in which, indeed, interesting nonlinear wave features are demonstrated. As a consequence, the preceding question may be answered. 相似文献
1000.
Min Seok Choi Howook Jeon Hyo Suk Kim Bo Hyun Jang Yoon Hee Lee Hoon Suk Park HyungWook Kim Dong Chan Jin 《Hemodialysis international. International Symposium on Home Hemodialysis》2017,21(1):E4-E8
Gabapentin is commonly used for controlling convulsions, restless pain syndrome, and pain in diabetic neuropathy. Common side effects include dizziness, somnolence, ataxia, peripheral edema, and confusion; gabapentin‐induced rhabdomyolysis is rarely reported. To date, the reported cases of gabapentin‐induced rhabdomyolysis have been associated with patients with multiple underlying diseases and assuming multiple medicines for various reasons. In this report, we describe a case of gabapentin‐induced rhabdomyolysis in a 32‐year‐old woman with no medical history. We also review related literature and discuss the possible mechanism and the association with other factors. This case shows that gabapentin can induce rhabdomyolysis in healthy patients and that clinicians must consider the possible association between gabapentin and rhabdomyolysis. 相似文献