• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.191.1-191.1
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• 2014

Crystallization has become the most popular technique for the separation of enantiomers since the Pasteur's discovery. To investigate mechanism of crystallization of chiral molecules, it is necessary to study self-assembled structures on two-dimensional surface. Here, we have studied two-dimensional self-assembled structures of an unnatural amino acid, (S)-${\beta}$-methyl naphthalen-1-${\gamma}$-aminobutyric acid (${\gamma}^2$-1-naphthylalanine) on Au(111) surface at 150 K using scanning tunneling microscopy (STM). At initial stage, we found two chiral honeycomb structures which are counter-clockwise and clockwise configurations in one domain. The molecules are arranged around molecular vacancies, dark hole. By further increasing the amounts of adsorbed ${\gamma}^2$-1-naphthylalanine, a well-ordered square packed structure was observed. In addition, we found the other structure that molecules were trapped in the pore of the hexagonal molecular assembly.

• Korean Management Science Review
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• v.18 no.2
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• pp.107-116
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• 2001

In the ring leading problem with demand splitting, traffic demands are given for each pair of nodes in an undirected ring network and a flow is routed in either of the two directions, clockwise and counter-clockwise. The load of a link is the sum of the flows routed through the link and the objective of the problem is to minimize the maximum link load on the ring. Recently, four different optimal a1gorithms have been developed for solving the problem. In this paper, we compare those algorithms in a single framework and conduct a computational study to evaluate the practical performance of those algorithms.

• Journal of the Korean Operations Research and Management Science Society
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• v.23 no.3
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• pp.49-62
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• 1998

In the ring loading problem, traffic demands are given for each pair of nodes in an undirected ring network with n nodes and a flow is routed in either of the two directions, clockwise and counter-clockwise. The load of a link is the sum of the flows routed through the link and the objective of the Problem is to minimize the maximum load on the ring. In the ring loading problem with integer demand splitting, each demand can be split between the two directions and the flow routed in each direction is restricted to integers. Recently, Vachani et al. ［INFORMS J. Computing 8 (1996) 235-242］ have developed an Ο(n$^3$) algorithm for solving this integer version of the ring loading problem and independently, Schrijver et al. ［to appear in SIAM J. Disc. Math.］ have presented an algorithm which solves the problem with ｛0,1｝ demands in Ο（n$^2$｜K｜ ) time where K denotes the index set of the origin-desㅇtination pairs of nodes having flow demands. In this paper, we develop an algorithm which solves the problem in Ο(n ｜K｜) time.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1678-1680
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• 1998

The purpose of this study is to obtain optimum arrangement of phase conductors in minimizing magnetic field from overhead transmission lines. Data of the transmission lines rated 345 kV of the KEPCO(Korea Electric Power Company)'s system were used. For a three phase-double circuit transmission line, low-reactance arrangement is optimum in minimizing magnetic fields. For a three phase-four circuit, optimum phase arrangement is a-b-c-b-a-c(lower two circuits, clockwise)/b-c-a-c-a-b(upper two circuits, clockwise).

• Ocean and Polar Research
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• v.21 no.2
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• pp.87-97
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• 1999

To estimate absolute transports by advection in the southwestern East Sea (Japan Sea), an inverse method was applied to CTD data obtained in July 1993. The relative velocities are calculated using the thermal wind equation. The inverse model was formulated to obtain a reference velocity based on the mass conservation in each of four vertical layers within a region enclosed by hydrographic sections and the coastal boundary. The flow patterns in the surface layer are clockwise and anti-clockwise in the regions south and northwest of Ulleung Island, respectively, and a strong northward flow appears in between them. In the second layer, the flow fields are generally weak. The inverse calculation yields the southward flow along the coast, and this suggests that the subsurface low salinity water in the Ulleung Basin is supplied by the southward transport along the east coast of Korea.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.87-94
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• 2009

Today's driver information system often features a rotary control type as a main controller for menu navigation. Population stereotype should be clearly understood in designing those systems to minimize the misunderstanding by the operator. This paper investigates stereotypes for rotary controlled menu interfaces and influences of contributing principles. A human factors experiment was conducted using various configurations of control-display layouts, cursor shapes/positions, and movement directions. The results showed that the control should be on the left of the display, with a rightward icon on the right side of the cursor, in order to match the stereotype. Regression analysis indicated that Warrick's principle was the most influential principle, followed by Icon shape, Icon position, Clockwise away, and Clockwise up principles. This study provides valuable information to designers of menu-based systems such as driver information systems and main control rooms that uses rotary controls.

• Proceedings of the IEEK Conference
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• 2002.07c
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• pp.2023-2026
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• 2002

This paper explains the study of controller design applied to SRM(Switched Reluctance Motor) concept. This controller executes controller algorithms via ${\mu}$-processor to increase stability and precise measurement, and VHDL (Very high speed integrated circuit Hardware Description Language) is designed to generate SRM driving signal. During initial period, SRM controller was designed to control .respective target RPM (Revolution per minutes) and PR (Proportional Integral Differential) coming from the PC(Personal Computer) monitor program, and receiving clockwise and counter-clockwise rotation signal and target RPM coming from the front panel, and receiving the location of rotational element and RPM generating from the position censor during activation period.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.124-131
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• 2015

Computational fluid dynamics (CFD) has been employed for the Heat exchanger efficiency of a counter flow heat exchanger. The Heat exchanger efficiency has been assessed by considering the computed Nusselt number and flow friction characteristics in the double pipes heat exchanger equipped with two types twisted-tapes: (1) single clockwise direction and (2) alternate clockwise and counterclockwise direction. Cold and hot water are used as working fluids in shell and tube side, respectively. Hot and cold water inlet mass flow rates ranging are between 0.04 and 0.25 kg/s, and 0.166 kg/s, respectively. The inlet hot and cold water temperatures are 54 and $30^{\circ}C$, respectively. The results obtained from the tube with twisted-tapes insert are compared with plain tube. Nusselt number and friction factor obtained by CFD simulations were compared with correlations available in the literature. The numerical results were found in good agreement with the results reported in literature.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.274-277
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• 2012

Large eddy simulation is applied to the turbulent flow and heat transfer in straight cooling passages with varying aspect ratio. The turbulent statistics of the flow and thermal quantities are calculated and the characteristics of Nusselt number are investigated. To scrutinize near-wall streamwise vortices, a conditional sampling technique is adopted. Clockwise and counter-clockwise rotating streamwise vortices are sampled and the probability density function of the vortex circulation Reynolds number and wall Nusselt number are calculated.

• ETRI Journal
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• v.41 no.3
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• pp.289-297
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• 2019

In this paper, a wideband, circularly polarized patch antenna is proposed that leverages the unidirectional resonant modes of a circular patch mounted on top of a grounded dielectric-ferrite substrate. The proposed antenna is fed via the proximity coupling method and several parasitically coupled patches are placed on a dielectric superstrate to enhance the impedance bandwidth of the antenna. The resonant modes of the structure rotate only in the clockwise or counter clockwise directions. In the frequency range where the effective permeability of the ferrite layer is negative, the resonance frequencies of these modes differ significantly, which produces a large axial ratio (AR) bandwidth. For the proposed antenna, the numerical results show the 10 dB impedance bandwidth to be around 44% and the 3 dB axial ratio bandwidth to be higher than 64%.