• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.158-165
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• 2002

This Paper deals with the headlamp lens surface temperature distribution of p/c headlamp using the three categories of H4 halogen bulbs. Glass is gradually replaced by P/C for the lens material off vehicle headlamp due to the weight reduction and stream lined body of a vehicle. With this trend, the newly established standards for a headlamp with a P/C lens in Europe requires that the heat generated by a bulb should not distort the lens surface. Also the requirements fur the bulb of a headlamp are being enforced in U.S.A & Europe. However, such requirements are not established yet in Korea. By using three kinds (60/55w, 100/90w, 130/90w) of H4 halogen bulbs in this experiment, the surface temperature distribution and Max. temperature on the lens were measured. The results of this study implies the necessity of requirement fur the bulb off headlamp.

• Transactions of the Korean Society of Automotive Engineers
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• v.8 no.6
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• pp.220-229
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• 2000

In the brake systems a proportioning valve which reduces the brake pressure at each wheel cylinder for anti-locking of rear wheels is closely related with the safety of vehicles. But, it is impossible for a present proportioning valve to exactly control brake pressure because mechanically it is an open loop control system. So, in this paper we describe a electronic brake pressure distribution system using a fuzzy controller in order to exactly control brake pressure using a close loop control system. The object of electronic brake pressure distribution system is to change an cut-in pressure and an valve slop of proportioning valve in order to obtain better good performance of brake system than with mechanical system.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.3
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• pp.614-620
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• 2009

The force distribution in multi-legged robots is a constrained, optimization problem. The solution to the problem is the set points of the leg contact forces for a particular system task. In this paper, an efficient and general formulation of the force distribution problem is developed using linear programming. The considered walking robot is a quadruped robot with a locked-joint failure, i.e., a joint of the failed leg is locked at a known place. For overcoming the drawback of marginal stability in fault-tolerant gaits, we define safety margin on friction constraints as the objective function to be maximized. Dynamic features of locked-joint failure are represented by equality and inequality constraints of linear programming. Unlike the former study, our result can be applied to various forms of walking such as crab and turning gaits. Simulation results show the validity of the proposed scheme.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.4
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• pp.660-668
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• 2007

In order to improve the efficiency of service restoration function in the current Distribution Automation System (DAS), in this paper it is proposed a more advanced and efficient service restoration approach using Multi-Agent technique based on distributed networks. In the current DAS, communication networks or protocol structures are centralized with communications between the central station and FRTU through 1:1 connection. In order to maintain the current systems and enhance the proposed Multi-Agent based service restoration scheme, a device of communication and intelligence, named MASX, is newly developed to make a FRTU as an agent to cooperate each others. the proposed system applied in a demo system for an distribution automation system and shows 8 times reduction of restoration time in restoration of blackouts.

• Fisheries and Aquatic Sciences
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• v.12 no.3
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• pp.240-248
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• 2009

Distribution and abundance of planktonic shrimps were studied in the southern sea of Korea from 1987 to 1991. Nine species of five genera belonging to three families were identified. Of these, Leptochela sydniensis and Lucifer intermedius were predominant species and Lucifer penicilifer and Lucifer typus were common species. Remaining five species, Acetes chinensis, Leptochela gracilis, Lucifer chacei, Process wheeleri and Sergestes similis occurred sporadically and rarely. The distribution pattern of planktonic shrimps varied with species and sampling periods. L. intermedius occurred abundantly along inshore waters. L. penicilifer and L. typus appeared in both inshore and offshore waters, but more abundantly in offshore waters under influence of the Tsushima Current. In conclusion, the distribution patterns of planktonic shrimps may be related with hydrographic characteristics and seasonality in the southern sea of Korea.

• Communications of the Korean Mathematical Society
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• v.19 no.1
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• pp.169-177
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• 2004

For a stationary field $\{X_{\b{j}},\b{j}{\;}\in{\;}{\mathbb{Z}}^d_{+}\}$ of associated random variables with distribution function $F(x)\;=\;P(X_{\b{1}}\;{\leq}\;x)$ we study strong consistency and asymptotic normality of the empirical distribution function, which is proposed as an estimator for F(x). We also consider strong consistency and asymptotic normality of the empirical survival function by applying these results.

• Earthquakes and Structures
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• v.11 no.3
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• pp.407-420
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• 2016

The aim of this study is to investigate the effect of vertical ground motion (VGM) on seismic behavior of reinforced concrete (RC) regular frame with construction joints, and determine more proper modeling method for cast-in-situ RC frame. The four-story RC frames in the regions of 7, 8 and 9 earthquake intensity were analyzed with nonlinear dynamic time-history method. Two different methods of ground motion input, horizontal ground motion (HGM) input only, VGM and HGM input simultaneously were performed. Seismic responses in terms of the maximum vertex displacement, the maximum inter-story drift distribution and the plastic hinge distribution were analyzed. The results show that VGM might increase or decrease the horizontal maximum vertex displacement depending on the value of axial load ratio of column. And it will increase the maximum inter-story drift and change its distribution. Finally, proper modeling method is proposed according to the distribution of plastic hinges, which is in well agreement with the actual earthquake damage.

• Smart Structures and Systems
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• v.12 no.6
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• pp.641-659
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• 2013

In this paper is studied the influence of the uncertain mass distribution over the floors on the choice of the optimal parameters of a hybrid control system for tall buildings subjected to wind load. In particular, an optimization procedure is developed for the robust design of a hybrid control system that is based on an enhanced Monte Carlo simulation technique and the genetic algorithm. The large computational effort inherent in the use of a MC-based procedure is reduced by the employment of the Latin Hypercube Sampling. With reference to a tall building modeled as a multi degrees of freedom system, several numerical analyses are carried out varying the parameters influencing the floors' masses, like the coefficient of variation of the distribution and the correlation between the floors' masses. The procedure allows to obtain optimal designs of the control system that are robust with respect to the uncertainties on the distribution of the dead and live loads.

• Microbiology and Biotechnology Letters
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• v.23 no.5
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• pp.499-505
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• 1995

Immobilization of anchorage-dependent animal cells was investigated using macroporous gelatin microcarriers developed in our laboratory. For the observation of the distribution of cells in macroporous beads, Vero-6 cells and CHO cells were cuttured and their distribution in macroporous beads was observed using a confocal microscope. In results, the final concentration of Vero-6 cells and CHO cells on macroporous beads was 2-3 times higher than that on commercial solid microcarriers (Cytodex-3). Also, macroporous microcarriers could hold cells in their macropores. Consequently, the pores protected cells against hydrodynamic shear. Based on Kolmogorov eddy length scale, the smaller eddies (80 $\mu $m) showed the detrimental effect on cells in macroporous beads as compared with 160 $\mu $m of eddies in conventional solid microcarriers.

• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.705-717
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• 2013

In this paper, we study the geometry of half lightlike submanifolds M of a semi-Riemannian manifold $\tilde{M}$ with a semi-symmetric non-metric connection subject to the conditions; (1) the characteristic vector field of $\tilde{M}$ is tangent to M, the screen distribution on M is totally umbilical in M and the co-screen distribution on M is conformal Killing, or (2) the screen distribution is integrable and the local lightlike second fundamental form of M is parallel.