• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2007.11a
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• pp.112-115
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• 2007

본 논문은 퍼지추론을 통해 개체의 유사성과 적합도의 종합적 평가를 이용한 유전알고리즘의 선태연산자를 제안한다. 단일 집단을 가상적으로 임의의 n 개의 개체군을 나누고, 개체의 적합도와 유사도에 기반한 퍼지추론을 통해, 효율적인 계층화를 구성하고자 한다. 동시에 점진형(steady-state) 진화방식과 결합시켜 계층화된 군집내에서 개체들이 조기에 수렴하는 현상을 방지해 줄 수 있도록 하고, 적은 개체를 이용하여 효율적인 진화가 가능하도록 구현하였다. 2가지 기만적 문제에 대해서 다른 선태 연산자들의 결과와 비교하였으며, 만족할만한 성능을 얻었다.

• Proceedings of the Korean Information Science Society Conference
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• 2003.10a
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• pp.253-255
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• 2003

오늘날 많은 가전제품들은 다양화. 쌍방성, 효율성, 개방성등 정보화 시대의 주요 특징들과 접목되어 생산되고 있으며, 이중 모바일 제품군(Low End)은 각광받는 주류 제품이라 할 수 있다. 그러나 대부분의 모바일 제품들은 그 특성상 파일 시스템을 지원하지 못하고 있기에, 본 논문에서 모바일 제품의 운영체제로서 파일 시스템이 지원되지 않는 실시간 운영체제(RTOS- Real Time Operation System)를 선택하여 가상머쉰(VM-Virtual Machine)을 설계 및 구현하였다. 위의 지원을 위해 자바 클래스 파일을 C 언어 형태로 변환하여 VM 과 직접적으로 링크하는 방법인 프리링킹(Prelinking), 프리로딩(Preloading) 혹은 로마이징(ROMizing)이라고 알려져 있는 기법을 도입하였다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05b
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• pp.366-369
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• 2004

본 논문은 인터넷 상의 PC 군을 네트워크로 연동하여 가상의 컴퓨팅 인프라를 구성하려는 연구에 관한 것이다. 자원의 복제 및 공유를 통해서 컴퓨팅 인프라 전반에 걸친 신뢰성과 결함감내 능력을 향상시키는 P2P 네트워크가 활발히 연구되고 있다. 그러나 현재까지의 P2P 네트워크는 복제된 데이터의 일관성 유지를 위해 노드들 간에 필요한 통신 매커니즘에 대한 고려가 부족하다. 본 논문은 이런 문제를 해결하기 위해서 그룹 통신 방식을 제안하고 IP 멀티캐스트 방식을 응용한 Spanning Tree 방식의 링 구성을 통하여 P2P 네트워크에서 그룹통신을 지원하기 위한 메시지 전송방식을 설명하고 자원의 복제를 통한 신뢰성 향상 기법에 대해서 소개한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.490-491
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• 2014

쿠쿠 샌드박스(Cuckoo Sandbox)는 가상머신을 이용해 악성코드를 자동으로 동적 분석할 수 있는 도구이다. 우선 악성코드의 MD5값을 이용하여 VirusTotal을 이용해 종류를 분류하고, 쿠쿠 샌드박스로 악성코드 동적을 분석하여 결과파일을 이용해 악성코드에서 호출한 API들에 대한 정보를 추출하고, 다양한 종류별 악성코드 그룹에 대해서 API빈도를 종합하고, 또한 다른 종류군의 악성코드 그룹과 API 빈도를 비교해 특정 종류의 악성코드 그룹에 대한 특징적인 API를 찾아내어 향후 이런 특징 API들을 이용해 악성코드의 종류를 자동으로 판정하기 위한 방법을 제시한다.

• Clinics in Shoulder and Elbow
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• v.11 no.2
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• pp.158-164
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• 2008

Purpose: We compared the results of arthroscopic Bankart repair using metal and biodegradable anchor fixation. Materials & Methods: We reviewed 26 patients with anterior shoulder instability treated by arthroscopic Bankart repair from October, 2006, to March, 2007, 15 patients with metal anchors and 11 patients with biodegradable anchors. The average age was 27.4 years old (range: 17~55) and mean follow-up was 14 months (range: 12~17 months). Functional outcome was evaluated using the Korean Shoulder Score for Instability (KSSI), Rowe's Bankart Grading scale (RBGS), ASES score, and UCLA scores. Results: In the metal-anchor group, the improvements of mean KSSI, ASES, UCLA score, and RBGS were 20.6, 24.0, 4.0, and 45.5, respectively. In the biodegradable anchor group, improvements of mean KSSI, ASES, UCLA score, and RBGS were 21.0, 23.6, 4.6, and 48.9. The improvements in final outcomes were not significantly different (p>.05). One metal problem and one traumatic redislocation occurred in the metal group. Conclusion: Both techniques produced satisfactory outcomes in the treatment of traumatic anterior instability. The biodegradable anchor group could also avoid problems with metal anchors.

• Journal of Korean Society of Transportation
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• v.21 no.2
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• pp.71-82
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• 2003

The shortest path problems(SPP) are critical issues in the military logistics such as the simulation of the War-Game. However, the existing SPP has two major drawbacks, one is its accuracy of solution and the other is for only one solution with focused on just link cost in the military transportation planning models. In addition, very few previous studies have been examined for the multi-shortest path problems without considering link capacity reflecting the military characteristics. In order to overcome these drawbacks, it is necessary to apply the multi-shortest paths algorithm reflecting un-expected military incidents. This study examines the multi-shortest paths in the real networks using Shier algorithm. The network contains both military link capacity and time-based cost. Also, the modes are defined as a platoon(group) rather than unit which is used in most of previous studies in the military logistics. To verify the algorithm applied in this study. the comparative analysis was performed with various sizes and routes of network which compares with Dijkstra algorithm. The major findings of this study are as follows ; 1) Regarding the unique characteristics of the military transportation plan, Shier algorithm, which is applied to this study, is more realistic than Dijkstra algorithm. Also, the time based concept is more applicable than the distance based model in the military logistics. 2) Based on the results from the various simulations of this study the capacity-constraint sections appeared in each scenarios. As a consequence, the alternatives are necessary such as measures for vulnerable area, improvement of vehicle(mode), and reflection of separated-marching column in the military manuals. Finally. the limits and future research directions are discussed : 1) It is very hard to compare the results found in this study. which is used in the real network and the previous studies which is used in arbitrary network. 2) In order to reflect the real military situations such as heavy tanks and heavy equipment vehicles. the other constraints such as the safety load of bridges and/or the height of tunnels should be considered for the future studies.

• Nuclear Engineering and Technology
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• v.19 no.4
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• pp.317-324
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• 1987

The purpose of this work is to present a spatial neutron kinetics computational scheme for the analysis of space-dependent transients like rod ejection accident of pressurized water reactors. In this work modified Borresen's 1.5 group coarse mesh scheme was formulated for the neutronic computation of the space-dependent transients and applied to the analysis of hypothetical rod ejection accident of KNU no. 1 PWR core at BOC, HZP. The computational accuracy of the modified Borresen's scheme is examined by comparing calculations for core power and control rod worths with startup core physics test results. Effects of such parameters as ejected rod worths and number of delayed neution group ell transient results as well as computational efficiency are also examined. OB this basis it is suggested that the modified Borresen's method is a useful scheme for the analysis of spatial neutron transients of PWR's.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.6B
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• pp.517-526
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• 2006

In order to achieve high capacity and reliable link quality in wireless communication, the significant efforts should be concentrated on mitigating interference between cells. To solve the interference problem, the newly introduced concept of a Distributed Wireless Communication System (DWCS) can provide the capability of joint control of the signals at multiple cells. This paper proposes a new concept of virtual cell: the Dual Virtual Cell (DVC), and also proposes DVC employment strategy based on DWCS network. The proposed system manages two kinds of virtual cell. One is the Active Virtual Cell which exists for user's actual data traffic and the other is the Candidate Virtual Cell which contains a set of candidate antennas to protect user's link quality from performance degradation or interruption. The proposed system constructs DVC by using antenna selection method. Also, for multi-user high-rate data transmission, the proposed system introduces multiple antenna technology to get a spatial and temporal diversity gam and exploits space-Time Trellis Codes known as STTC to increase a spectral efficiency.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.10
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• pp.137-145
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• 2007

The purpose of this study is developing a virtual bicycle system for improving the ability of postural balance control for adults in various age groups. The system consists of an exercise bicycle that allows tilt in accordance with the postural balance of the subject in the system, a visual display that shows virtual road, and a visual feedback system. The rider of the system tries to maintain balance on the bicycle with a visual feedback of a virtual road while the pedaling speed, the heading direction, and various weight distribution information are updated to the subject as visual feedbacks in the display. A series of experiments were performed with various subjects to find the factors related to postural balance control in the system. The related parameters obtained were weight shift, magnitude of the deviation from the center of the virtual road, and variables related to the movement of the center of pressure. The results found that the ability to control postural balance in the system improved with the presentation of visual feedback information of the distribution of weight. It was also found that the general performance of the subject on balance in the system improved after ten days long training. The results show that the newly developed system can be used for the diagnosis of postural balance as well as for the stimulation of various senses such as vision and somatic sense in the field of rehabilitation training.

• Journal of the Korea Society for Simulation
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• v.23 no.4
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• pp.171-180
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• 2014

Our Automatic Replanning enables simulation entities to execute goal oriented behavior planning by dynamic behavior linking. Existing methods especially in Semi-Automated Forces (SAF) are mainly executing strict plans which are given at initial stage, thus they are not effective to cope with contingencies especially in a human in the loop simulation where humans interrupt. Moreover, those usually suffer from explosion of behavior combination in attempt to describe all possible countermeasures, and such combinations may be prone to being inconsistent to the situations. Our method generates behavior sequence in which behavior are linked from the goal in the manner of back-propagation. Each behavior has tags of pre/post-conditions. The tags are linked dynamically according to a certain contingency. The method is being applied to a national defense research project to show feasibility.