• IE interfaces
• /
• v.10 no.2
• /
• pp.1-13
• /
• 1997

The problem of the formation of machine-part cells in FMS is a very important issue at the planning and operating stages of FMS. This problem is inherently a combinatorial optimization problem, proven to be NP-complete(or, NP-hard). Among the several kinds of approaches which have been applied to solve the combinatorial optimization problems, the Simulated Annealing(SA) algorithm, a technique of random search type with a flexibility in generating alternatives, is a powerful problem solving tool. In this paper, the SA algorithm is used to solve machine cell-part family formation problems. The primary purpose of the study is to find the near-optimal solution of machine cell-part family formation problem, whare the product volume and number of operations are prespecified, that can minimize the total material handling cost caused by exceptional elements and intercell moves as much as possible. The results show that the SA algorithm is able to find a near-optimal solution for practical problems of the machine cell-part family formation.

• Journal of Institute of Control, Robotics and Systems
• /
• v.8 no.5
• /
• pp.425-433
• /
• 2002

After the removal of SA (Selective Availability), horizontal accuracy of 25m(2dRMS) is easily obtained using GPS (Global Positioning System). In this paper, the error characteristics without SA are analyzed and a navigation algorithm concerns this error characteristics is proposed to further improve the accuracy. The proposed method utilizes the relationship between elevation angle and errors that are remained after ionospheric and troposheric delay compensation. The relationship is derived from real measurements and used as a weighting matrix of weighted least squares estimator. Furthermore, a RAIM (Receiver Autonomous Integrity Monitoring) technique is included to remove abnormal measurements affected by multi-path or low SNR (Signal-to-Noise Ratio). It is shown that using the proposed method, more than 4 times accurate result, which is comparable with DGPS (Differential GPS), can be obtained from experiments with real data. Besides accuracy and reliability, the proposed method reduces large jumps in position and maintains better performance than a method using mask angle to completely remove satellites below this mask angle. Thus it is expected that the proposed method can be efficiently applied to land navigation where some satellites are blocked by building or forest.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.6C
• /
• pp.659-667
• /
• 2003

IPsec refers to a standardized set of security protocols and algorithms which can provide the integrity, the authentication and the confidentiality services for IP packets in the Internet. Between two security gateways, IPsec provides the access control, the connectionless Integrity, data origin authentication, the anti-replay, and the confidentiality services, not only to the IP layer but also to the upper layers. In this paper, we describe a VPN (Virtual Private Network) testbed configuration using the FreeS/WAN and analyze the ISAKMP messages exchanged between the linux security gateway during the IKE SA setup. Also, we describe our development of an IPSEC encryption verification tool which can be used conveniently by VPN administrators.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2012.07a
• /
• pp.343-346
• /
• 2012

추천 엔진의 지속적인 성능 향상을 위해서는 객관적 성능 평가가 이루어져야 하지만, 콘텐츠 추천 기술은 평가 데이터 구축이 어렵고 평가를 위한 심도 깊은 연구가 이루어지지 못하여 많은 어려움을 가지고 있다. 본 논문은 콘텐츠 추천 시스템의 객관적인 평가를 시스템 구축에 대한 연구이다. 추천 알고리즘의 효율적이고 객관적인 성능 평가를 위하여 기존 연구들을 분석하여 대표적인 성능평가 양식들을 구현하였다. 통계적인 평가를 위한 사용자 데이터를 수집하였으며 데이터 크기, 평가방식, 추천 알고리즘의 모듈 별 성능 추이를 쉽게 변경하고 관찰할 수 있도록 인터페이스를 설계하였다. 이러한 평가 시스템의 도입으로 콘텐츠 추천 알고리즘의 지속적인 성능 보완을 기대 할 수 있을 것이다.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.33B no.6
• /
• pp.149-155
• /
• 1996

In this paper, we designed binary phase grating with SA (simulated annealing) algorithm for image generation, and used LCTV(liquid crystal television) as phase modulator. We generated optical image using LCTV which controlled by personal computer in real time. Many parameters in SA algorithm are determined by average deviation of the cost function, not experimental method. It was confirmed that the LCTV could be used as a phase modulator through mach-zehnder interferometering experiment. The various optical images are generated in real itme by fourier transforming of the phase gratings on LCTV which is controlled by personal computer and they can be used for optical interconnection in a neural network and addressing information in a volume hologram etc.

• Proceedings of the KIEE Conference
• /
• 1998.07b
• /
• pp.623-625
• /
• 1998

This paper focuses on the fast convergence in nonlinear parameter optimization which is necessary for the fitting of nonlinear models to data. The simulated annealing(SA) and genetic algorithm(GA), which are widely used for combinatorial optimization problems, are stochastic strategy for search of the ground state and a powerful tool for optimization. However, their main disadvantage is the long convergence time by unnecessary extra works. It is also recognised that gradient-based nonlinear programing techniques would typically fail to find global minimum. Therefore, this paper develops a modified SA which is the SDS(Stochastic deterministic stochastic) algorithm can minimize cost function of optimal problem.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.11 no.6
• /
• pp.53-65
• /
• 2001

Authentication mechanism for W-CMDA IMT-2000 system is developed by 3GPP TSG SA WG3. We simulated the mechanism and algorithms. In this paper, we overview 3GPP authentication procedures and present results of our simulation. We validate the mechanism and parameters transmitted during authentication procedures and we also discuss parameters which are unclear in specification.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.53 no.8
• /
• pp.49-58
• /
• 2016

In designing heterogeneous architecture based application-specific network-on-chips (NoCs), the opportunities of performance improvement would be expanded when applying asynchronous on-chip communication protocol. This is because the wire latency can be configured independently considering the wirelength of each link. In this paper, we develop the delay model of link-wire-length in asynchronous NoC and propose simulated annealing (SA) based floorplan-aware topology generation algorithm to optimize link-wirelengths. Incorporating the generated topology and the associated latency values across all links, we evaluate the performance using the floorplan-annotated sdf (standard delay format) file and RTL-synthesized gate-level netlist. Compared to TopGen, one of general topology generation algorithms, the experimental results show the reduction in latency by 13.7% and in execution time by 11.8% in average with regards to four applications.

• Journal of Korea Multimedia Society
• /
• v.10 no.10
• /
• pp.1284-1294
• /
• 2007

In this paper, a blind nonlinear channel equalization is implemented by using a Modified Fuzzy C-Means (MFCM) algorithm. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.

• Proceedings of the Korea Inteligent Information System Society Conference
• /
• 2007.05a
• /
• pp.382-388
• /
• 2007

In this paper, a modified Fuzzy C-Means (MFCM) algorithm is presented for nonlinear blind channel equalization. The proposed MFCM searches the optimal channel output states of a nonlinear channel from the received symbols, based on the Bayesian likelihood fitness function instead of a conventional Euclidean distance measure. Next, the desired channel states of a nonlinear channel are constructed with the elements of estimated channel output states, and placed at the center of a Radial Basis Function (RBF) equalizer to reconstruct transmitted symbols. In the simulations, binary signals are generated at random with Gaussian noise. The performance of the proposed method is compared with that of a hybrid genetic algorithm (GA merged with simulated annealing (SA): GASA), and the relatively high accuracy and fast searching speed are achieved.