• Proceedings of the KIEE Conference
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• 2003.07d
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• pp.2495-2497
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• 2003

본 논문에서는 다수의 AGV를 이용한 물류자동화 시뮬레이션에 대해 연구하였다. 각각의 AGV가 독립적으로 명령을 수행하도록 가상의 AGV를 제안하고 이미 연구된 AGV의 주행경로 표현방법, 경로망 구성방법을 이용하였다. 작업요구시 주어진 작업을 가장 빨리 수행 할 수 있는 AGV를 선정하고 최적 경로 계획을 수행하였다. 그리고 작업을 수행 중인 AGV는 경로 합류점에서의 교착상태(dead lock)와 충돌이 발생할 수 있는데 이를 방지하기 위한 통제구역을 정의하고 교통제어를 수행하였다.

• Journal of KIISE:Computer Systems and Theory
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• v.32 no.10
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• pp.530-540
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• 2005

Virtual colonoscopy is an easy and fast method to reconstruct the shape of colon and diagnose tumors inside the colon based on computed tomography images. This is a non-invasive method, which resolves weak points of previous invasive methods. The path for virtual colonoscopy should be generated rapidly and accurately for clinical examination. However, previous methods are computationally expensive because the data structure such as distance map should be constructed in the preprocessing and positions of all the points of the path needs to be calculated. In this paper, we propose the automatic path generation method based on visibility to decrease path generation time. The proposed method does not require preprocessing and generates small number of control points representing the Path instead of all points to generate the path rapidly. Also, our method generates the path based on visibility so that a virtual camera moves smoothly and a comfortable and accurate path is calculated for virtual navigation. Also, our method can be used for general virtual navigation of various kinds of pipes.

• Journal of Korean Society of Transportation
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• v.17 no.2
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• pp.163-178
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• 1999

Conventional shortest path searching a1gorithms are based on the partial searching method such as Dijsktra, Moore etc. The a1gorithms are effective to find a shortest path in mini-modal condition of a network. On the other hand, in multi-modal case they do not find a shortest path or calculate a shortest cost without network expansion. To copy with the problem, called Searching Area Problem (SAP), a global searching method is developed in this paper with Genetic Algorithm. From the results of two examples, we found that the a1gorithm is useful to solving SAP without network expansion.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.111-120
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• 2003

A new stress path test method, which is more suitable f3r evaluating settlements of clay deposits, was introduced. This new method is basically based on back pressure equalization concept and makes it possible to estimate deformations corresponding to all points on a specific stress path by only one test. As a result, deformation characteristics of a clay deposit can be predicted by a few tests and the more practical application of stress path method can be realized. In addition, anisotropic deformation behaviors following arbitrary stress paths also can be experimentally measured by this test method. Experimental applicability of the proposed method was confirmed by performing various stress path tests on remolded kaolinite samples and the actual process to evaluate overall deformation characteristics and settlements was also presented.

• Journal of Distribution Research
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• v.14 no.2
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• pp.1-30
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• 2009

The purpose of this study is to investigate the direct and indirect modes of influences environmental dynamism exerts on opportunism, one of important relationship factors. This study particularly delves into the indirect modes of influence in terms of control strategy (control mechanism) and control structure (bureaucratic structuring). To this end, a survey research has been conducted of 200 suppliers in business relationships with Korean hypermarket retailers. An analysis of the collected data indicates that while environmental dynamism has a positive influence on the control mechanisms such as monitoring and incentives, it does not have a negative influence on the control structure such as participation. And then it has a positive influence on the opportunism of suppliers. In addition, participation has a negative influence on the opportunism, but monitoring and incentives do not have a negative influence on it. This study discusses how both retailers and their suppliers should respond to the domestic retail business environment with highly dynamic characteristics, in order to achieve a long-term win-win partnership with one another. It also presents ideas to retailers with regard to what kinds of management strategies and management efforts required to effectively control the opportunism of suppliers.

• Proceedings of the Korean DIstribution Association Conference
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• 2007.08a
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• pp.159-186
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• 2007

In today's world, the ability to adapt to the rapidly changing environment is fundamental to the survival and success of any organizations. This is particularly true for the Korean retailing industry which is in the throe of sweeping developments. Against the backdrop of an increasing importance of the environmental factors, it is imperative to look into what efforts are required of corporate enterprises in order to achieve successful long-term partnerships between and among the parties involved in the retail value chain. In spite of the critical importance of the need to understand the environmental factors and their influences on the retail value chain, a serious theoretical and empirical study into this subject has never been conducted. Moreover, previous research has overlooked the various mechanisms influencing the value chain in terms of ,control strategy' and 'control structure'. The purpose of this study is to investigate the direct and indirect modes of influences environmental dynamism exerts on opportunism, one of important relationship factors. This study particularly delves into the indirect modes of influence in terms of control strategy (control mechanism) and control structure (bureaucratic structuring). To this end, a survey research has been conducted of 200 suppliers in business relationships with Korean hypermarket retailers. The survey results show that environmental dynamism has a positive correlation with the opportunism of suppliers. In addition, the control mechanisms such as monitoring and incentives employed by retailers, in turn, have an indirect influence on the opportunism of suppliers. In other words, the monitoring of retailers has a positive correlation with the opportunism of suppliers, while the use of bureaucratic structuring has a negative correlation with opportunism. This study discusses how both retailers and their suppliers should respond to the domestic retail business environment with highly dynamic characteristics, in order to achieve a long-term win-win partnership with one another. It also presents ideas to retailers with regard to what kinds of management strategies and management efforts required to effectively control the opportunism of suppliers.

• The Transactions of the Korea Information Processing Society
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• v.2 no.3
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• pp.374-381
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• 1995

For designing radio communication systems, radio-channel effects must be considered in order to obtain the desired communication quality, transmitting power, transmission speed and bit error rate. In radio channel, one of major factors that degrade communication quality is multipath fading between transmitting and receiving points. Therefore, a channel model which can describe fading effects correctly is requested. This paper deals with the composition of the channel simulator model that describes multipath fading effects and delay times which occur in the channel. For the performance analysis of the proposed model, trandmitting signal is used in the simulation. From simulation results, it can be shown that probability density function. level crossing rates and average fading-duration time distribution of the faded receive signal are very similar with theoretic values.

• Proceedings of the Korean Information Science Society Conference
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• 2006.06b
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• pp.382-384
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• 2006

본 논문에서는 저해상도 한글 영상을 자소 단위로 분리하는 방법을 제안한다. 비디오 자막이나 저해상도 스캔 영상의 경우 자소간 획이 접촉되거나 잡영이 많이 포함되어 기존의 자소 분할 방법으로는 한계가 있다. 한자 문자열을 문자 단위로 분할하는데 사용된 비선형 분할 경로 알고리즘을 한글 낱자 영상에 적용하여 자소 단위로 분할한다. 기존의 분할 경로 알고리즘을 한글 자소 분할에 효과적으로 적용하기 위해서 우세점 탐지 알고리즘을 이용하여 자소간 접촉점을 찾고 이를 바탕으로 생성된 분할 경로에 따라 여러 개의 자소 후보 영상이 생성된다. 자소 영상을 자소 인식기로 인식한 결과 높은 인식률을 보이는 것을 실험을 통하여 확인하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.05a
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• pp.198-201
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• 2021

무인 항공기(UAV, Unmanned Aerial Vehicles)는 높은 기동성을 가지며 설치 비용이 저렴하다는 이점이 있어 홍수, 지진 등의 재난 재해 감시 시스템에 이용되고 있다. 재난 재해 감시 시스템에서 UAV는 지상에 위치한 사물인터넷(IoT, Internet of Things) 기기로부터 데이터를 수집하는 임무를 수행하기 위해 계획된 항로를 따라 비행한다. 이때 UAV가 정상 경로로 비행하기 위해서는 실시간으로 GPS 위치 확인이 가능해야 한다. 만일 UAV가 계산한 현재 위치의 GPS 정보가 잘못될 경우 비행경로에 대한 통제권을 상실하여 임무 수행을 완료하지 못하는 결과가 초래될 수 있다는 취약점이 존재한다. 이러한 취약점으로 인해 UAV는 공격자가 악의적으로 거짓 GPS 위치 신호를 전송하는GPS 스푸핑(Spoofing) 공격에 쉽게 노출된다. 본 논문에서는 신뢰할 수 있는 시스템을 구축하기 위해 지상에 위치한 기기가 송신하는 신호의 세기와 GPS 정보를 이용하여 UAV에 GPS 스푸핑 공격 여부를 탐지하고 공격당한 UAV가 경로를 이탈하지 않도록 대응하기 위해 연합학습(Federated Learning)을 이용하는 방안을 제안한다.

• Convergence Security Journal
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• v.23 no.5
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• pp.107-116
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• 2023

The management of professional manpower with expertise in performing specific tasks can be said to be a very important issue at the national level. Recently, interest in industrial technology protection experts continues to expand, but difficulties are growing due to the lack of policy evidence. Considering these points, this study conducted a fact-finding survey on personnel in charge of industrial technology protection, and through this, quantitative, qualitative, and job path analysis were performed for related job performers. These results are considered to be significant in that they can be used as basic information for fostering industrial technology protection experts in the future.