• Natural Product Sciences
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• v.9 no.4
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• pp.220-222
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• 2003

Two new abietane diterpenes with rearranged skeleton; aegyptinol and aegyptinone C; have been isolated and identified for the first time from the anti-microbial petroleum ether extract of the roots of Salvia aegyptiaca L. Their chemical structures have been elucidated by interpretation of the detailed 1D-and 2D-NMR spectra, as well as other spectroscopic tools. In addition, full assignment of $^{13}C-NMR$ of aegyptinone B was also conducted for the first time.

• Journal of the Korean Institute of Telematics and Electronics C
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• v.34C no.10
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• pp.8-18
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• 1997

In FPGAs, we may use the property of the routing architecture for their routing compared to the routing in the conventional layout style. Especially, the Xilinx XC4000 series FPGAs have very special routing architecture in which the routing problem is equivalent to the two dimensional track assignment problem. In this paper, we propose a new FPgA detailed routing method by developing a two dimensional trackassigment heuristic algorithm. The proposed routing mehtod accept a global routing result as an input and obtain a detailed routing such that the number of necessary wire segments in each connection block is minimized. For all benchmark circuits tested, our routing methd complete routing results. The number of used tracks are also similar to the results by thedirect routing methods.

• Journal of Aquaculture
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• v.15 no.3
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• pp.139-143
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• 2002

Saringosterols have been isolated from the sponge Penares incrustans. The structure of these compounds have been determined by extensive 2-D NMR experiments such as $ ^1 H$ COSY, HMQC, and HMBC and by comparison with published data. Assignment for carbons of saringosterols for the first time has been done.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.3
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• pp.218-223
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• 2012

Maintenance and improvement of the graph connectivity is very important for decentralized multi-agent systems. Although the CBBA (Consensus-Based Bundle Algorithm) guarantees suboptimal performance and bounded convergence time, it is only valid for connected graphs. In this study, we apply a decentralized estimation procedure that allows each agent to track the algebraic connectivity of a time-varying graph. Based on this estimation, we design a decentralized gradient controller to maintain the graph connectivity while agents are traveling to perform assigned tasks. Simulation result for fully-actuated first-order agents that move in a 2-D plane are presented.

• The Journal of the Acoustical Society of Korea
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• v.23 no.2
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• pp.109-116
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• 2004

This paper deals with data association using 3 sets of passive linear array sonars (PUS) geometrically positioned in a Y-shaped configuration, but fixed in an underwater environment. The data association problem is directly transformed into a 3-D assignment problem, which is known to be NP-hard. For generic passive sensors, it can be sotted using conventional algorithms, while it in PLAS becomes a formidable task due to the presence of bearing ambiguity. In particular, we proposed data association method robust to bearing measurements errors by incorporating frequency information and analyze a region of ghost problem by geometrical relation PUS and target. We analyzed the effectiveness of the proposed method by representative simulation in multi-target.

• International Journal of Automotive Technology
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• v.8 no.2
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• pp.211-217
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• 2007

The wheel slip control systems are able to control the braking force more accurately and can be adapted to different vehicles more easily than conventional ABS (Anti-lock Brake System) systems. In realizing the wheel slip control systems, real-time information such as the tire braking force at each wheel is required. In addition, the optimal target slip values need to be determined depending on the braking objectives such as minimum braking distance and stability enhancement. In this paper, a robust wheel slip controller is developed based on the adaptive sliding mode control method and an optimal target slip assignment algorithm is proposed for maximizing the braking force. An adaptive law is formulated to estimate the braking force in real-time. The wheel slip controller is designed based on the Lyapunov stability theory considering the error bounds in estimating the braking force and the brake disk-pad friction coefficient. The target slip assignment algorithm searches for the optimal target slip value based on the estimated braking force. The performance of the proposed wheel slip control system is verified in HILS (Hardware-In-the-Loop Simulator) experiments and demonstrates the effectiveness of the wheel slip control in various road conditions.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5253-5270
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• 2016

With device-to-device (D2D) communications, an inactive user terminal can be utilized as a relay node to support multi-hop communication so that connective experience of the cell-edge user as well as the capacity of the whole system can be significantly improved. In this paper, we investigate the spectrum sharing for a cooperative relay assisted D2D communication underlying a cellular network. We formulate a joint relay selection and channel assignment problem to maximize the throughput of the system while guaranteeing the quality of service (QoS) requirements of cellular users (CUs) and D2D users (DUs). By exploiting coalition formation game theory, we propose two algorithms to solve the problem. The first algorithm is designed based on merge and split rules while the second one is developed based on single user's movement. Both of them are proved to be stable and convergent. Simulation results are presented to show the effectiveness of the proposed algorithms.

• Bulletin of the Korean Chemical Society
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• v.18 no.8
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• pp.861-864
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• 1997

Luminescence spectrum of Na3[Eu(ODA)3]·7H2O (ODA≡oxydiacetato) was measured at various temperatures. The characteristic band splitting within 5D0→7FJ (J = 1, 2, 3 and 4) were phenomenologically simulated by using crystal field theory. The set of crystal field parameters reproduces the emission lines in a satisfactory manner with a rms deviation of 21.4 cm-1. It leads the reliable assignment of the luminescence bands and the energy level scheme of 7FJ (J = 1, 2, 3 and 4) multiplets.

• Journal of Korean Society of Transportation
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• v.36 no.2
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• pp.155-168
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• 2018

In this study, we studied the directional pattern of entering the intersection from the intersection upstream link prior to predicting short future (such as 5 or 10 minutes) intersection direction traffic volume on the interrupted flow, and examined the possibility of traffic volume prediction using traffic assignment model. The analysis method of this study is to investigate the similarity of patterns by performing cluster analysis with the ratio of traffic volume by intersection direction divided by 2 hours using taxi DTG (Digital Tachograph) data (1 week). Also, for linking with the result of the traffic assignment model, this study compares the impact area of 5 minutes or 10 minutes from the center of the intersection with the analysis result of taxi DTG data. To do this, we have developed an algorithm to set the impact area of intersection, using the taxi DTG data and traffic assignment model. As a result of the analysis, the intersection entry pattern of the taxi is grouped into 12, and the Cubic Clustering Criterion indicating the confidence level of clustering is 6.92. As a result of correlation analysis with the impact area of the traffic assignment model, the correlation coefficient for the impact area of 5 minutes was analyzed as 0.86, and significant results were obtained. However, it was analyzed that the correlation coefficient is slightly lowered to 0.69 in the impact area of 10 minutes from the center of the intersection, but this was due to insufficient accuracy of O/D (Origin/Destination) travel and network data. In future, if accuracy of traffic network and accuracy of O/D traffic by time are improved, it is expected that it will be able to utilize traffic volume data calculated from traffic assignment model when controlling traffic signals at intersections.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2011.07a
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• pp.31-34
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• 2011

본 논문에서는 2D-3D 변환 후, 입체감 수정에 관련한 피드백 시스템과 그에 맞게 적용되는 적응적 관계식을 제안한다. 2D-3D 변환을 통해 우선 깊이 영상을 생성하고 이를 이용하여 깊이 영상 기반 렌더링(DIBR)을 통해 수평방향의 이동을 계산하여 좌영상과 우영상을 생성한다. 그러나 깊이 정보 기반 렌더링 후 사용자 선호에 따라 입체감을 수정할 필요가 있을 때 깊이 영상을 재생성 해야 하는 문제점이 발생하며 이를 극복하고자 피드백 시스템을 통한 두 개의 조절 파라메터를 소개 한다. 즉, 'Pull-in'혹은 'Push-away'의 입체감을 조절 할 수 있는 시차 이동식을 제안한다.