• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2005년도 추계학술대회 및 정기총회
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• pp.3-9
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• 2005

The recent notion of Network Centric Warfare (NCW) emphasizes the ability to distribute right information at the right time to maximize the combat effectiveness. Accordingly, in the modern combat system the importance of non-physical element, such as communication system is increasing. However, an NCW-support communication network system is expensive. Therefore, it is essential to develop a proper combat system evaluation method to establish an efficient NCW-support combat system. Traditionally, combat system effectiveness is measured in terms of physical elements such as men and fire power. Obviously, such method is hardly applicable to a modern combat system To overcome this difficulty, we propose an evaluation model based on CA (Cellular Automata) simulation. A set of preliminary combat simulations show that CA simulation may be promising in evaluating non-physical element of a modem combat system.

• Journal of information and communication convergence engineering
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• 제9권2호
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• pp.224-229
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• 2011

Cellular Automata is a discrete dynamical system that can be completely described in terms of local relation. For any given image, the system can save its features as well as increase or decrease the brightness of it locally through consideration of optimized transition in succession. These transitions in succession satisfy the function "Lyapunov" and have sequential movements. This study suggests the way of noise reduction for each image with the use of the Sequential Cellular Automata system. The mentioned transition in succession gives stable results with high-convergence performance to random noises and PSNR (Peak Signal-to-Noise Ratio) using histograms and MSE (Mean Square Error) for verification of effectiveness.

• Journal of Information Processing Systems
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• 제6권3호
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• pp.403-412
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• 2010

Multi-Relay Networks should accommodate mobile users of various speeds. The cellular system should meet the minimum residency time requirements for handover calls while considering an efficient use of available channels. In this paper, we design speed-sensitive handover under dynamic hierarchical cellular systems, in which mobile users are classified according to the mean speed of mobile users and each class has its cellular layer. In order to meet the minimum residency time, the cell size of each cellular layer is dynamically determined depending on the distributions of mean speeds of mobile users. Since the speed-dependent non-preferred cell can provide a secondary resource, overflow and take-back schemes are adopted in the system. We develop analytical models to study the performance of the proposed system, and show that the optimal cell size improves the blocking probability.

• 한국컴퓨터정보학회논문지
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• 제24권7호
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• pp.79-85
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• 2019

We investigate the D2D utility maximization in the cellular system. We focus on the non cooperative game theoretic approach to maximize the individual utility. Cellular system's perspective, interference from the D2D links must be limited to protect the cellular users. To accommodate this interference issue, utility function is first defined to control the individual D2D user's transmit power. More specifically, utility function includes the pricing which limits the individual D2D user's transmit power. Then, non cooperative power game is formulated to maximize the individual utility. Distributed algorithm is proposed to maximize the individual utility, while limiting the interference. Convergence of the proposed distributed algorithm is verified through computer simulation. Also the effect of pricing factor to SIR and interference is provided to show the performance of the proposed distributed algorithm.

• 한국컴퓨터정보학회논문지
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• 제24권5호
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• pp.19-26
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• 2019

In this paper, we consider the D2D Transmitter(Tx) and Receiver(Rx) pair assignment problem in the cellular system. Sharing the resource of the cellular system, D2D users may cause interference to the cellular system, though it is beneficial to improve the D2D user Capacity. Therefore, to protect the cellular users, D2D transmit power should be carefully controlled. Previously, optimal Tx-Rx assignment to minimize the total transmit power of users was investigated. Accordingly, the iterative algorithm to find the optimum Tx-Rx asignment was obtained. In this work, we consider the case where Tx group users becomes Rx group users, and Rx group users become Tx group users. We prove that the Tx-Rx assignment problem has the duality property. We present the numerical examples that show the duality between U-link and D-link.

• 한국통신학회논문지
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• 제28권7A호
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• pp.503-510
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• 2003

CDMA 셀룰라 시스템은 같은 시간에 같은 주파수를 모든 사용자들이 같이 사용하므로 자기 신호 외의 다른 사용자의 신호는 간섭으로 나타나 통신 품질에 영향을 미친다. 이 간섭의 양에 따라 단위 셀당 사용자 수로 정의되는 시스템의 용량이 결정되며 간섭량의 정확한 계산이 이루어져야 시스템 성능 평가를 정확히 할 수 있다. 본 논문은 임의의 겹(tiers) 구조를 갖는 다중 셀 구성의 CDMA 셀룰라 시스템의 타셀 간섭량을 계산하기 위해 Riemann-Zeta 함수를 이용하여 임의의 전파 감쇄 지수에도 적용할 수 있는 근사식을 제안하였고, 제안된 식의 수치 결과와 시뮬레이션 결과를 비교하여 그 효용을 살펴보았다. 제안된 근사식을 이용해 계산한 타셀 간섭량과 시스템 용량은 시뮬레이션을 통해 얻은 결과를 중심으로 상한과 하한을 이루고 있으며 겹 수에 따른 값의 변화가 평균 간섭 및 용량 계산치와 일치하는 결과를 얻었다. 제안된 타셀 간섭 근사식은 복합적인 전파 환경이 공존하는 계층셀(Hierarchical Cellular) 시스템에서의 간섭 및 용량 계산과 알고리즘 검증에 유용하게 사용될 수 있을 것으로 생각된다.

• 한국통신학회논문지
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• 제30권3A호
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• pp.203-208
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• 2005

To solve the cost problem of micro/picocell system, the fiber-optic cellular system was proposed. In this system, all channel elements are managed in Central Station, not in each base station. Also, all channel elements in a system can be dynamically assigned when the Spectrum Delivery Switch (SDS) is used. In this paper, we propose and analyze a new intergroup handoff scheme in the fiber-optic cellular system. The proposed scheme supports handoff with keeping current channel. Performance is evaluated with respect to the blocking probability and the handoff refused probability in both systems with SDS and without SDS. The numerical results show that the proposed scheme provides better performance than conventional soft handoff scheme.

• 안보군사학연구
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• 통권9호
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• pp.257-282
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• 2011

In this paper, we propose an architecture design of military operation system utilizing cellular networks. The main contribution of this paper is to provide a cost-effective military operation solution for ground forces, which is based on IT(information technology). By employing the cellular phones of officers' and non-commissioned officers' as the tools of operational communication, the proposed system can be constructed in the minimum duration and be built on the four components: command and control system, gateway, security system, and terminal(cell phone). This system is most effective for the warfare of limited area, but the effectiveness does not decrease under the total war covering the whole land of Korea. For the environmental change of near future, expanded architecture is also provided to utilize the functionalities of smart phones.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2000년도 THE THIRD INTERNATIONAL CONFERENCE ON AGRICULTURAL MACHINERY ENGINEERING. V.II
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• pp.295-299
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• 2000

We have developed bio-system derived algorithm: Leaf Cellular Automata(LCA). LCA are one form of cellular automata. LCA are reffered to activity of a leaf. LCA have four layers: the "CO$_2$ Layer", the "Stoma Layer", the "Starch Layer" and the "Water Layer". In order to evaluate this optimization algorithm, we used a pattern matching problem.

• 한국생산제조학회지
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• 제23권6호
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• pp.580-589
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• 2014

Demands for automation in the cell production process of IT products are becoming increasingly sophisticated. In particular, the dual-arm robot has drawn attention as a solution because it has a flexibility and works similarly to humans. In this paper, we propose an automation system for cellular phone packing processes using two dual-arm robots. Applied robots are designed with specifications to meet the requirements of cellular phone packing jobs. In addition, a robotic cell production system is proposed by applying a method of task allocation for efficient packing of cellular phones. Specifically, a task is assigned to reduce takt-time and to avoid collision between two robots. Finally, we discuss some experimental results that include the packing job of five unit boxes with seven kinds of accessories.