• 한국국방경영분석학회지
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• 제32권2호
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• pp.114-130
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• 2006

본 논문은 아인스타인 시뮬레이션모형을 활용하여 상륙전을 묘사하는 복잡계이론을 다룬다. 아인스타인모형은 지상전에서 창발적인 자기조직화를 실험하기 위한 행위자 기반 모델이다. 상륙전의 다양한 형태중 상륙기습, 상륙돌격작전을 아인스타인 모형을 이용 구축하였으며 다양한 입력요소의 변경을 통하여 공간적 요소와 정성적 요소에 따른 전투양상의 변화를 확인할 수 있다. 즉, 통신요소의 변경, 탐지센서의 변경, 병력 재배치, 병력의 분산과 집중, 정성요소의 변경 등을 통해서 기존 란체스터형 전투모형의 단점을 보완함과 동시에 다양한 형태의 전투에 대한 모의 가능성과 발전 가능성을 확인할 수 있다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.2346-2349
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• 2005

Distributed Autonomous Robotic System (DARS) is defined as a system that independent autonomous robots in the restricted environments infer their status from pre-assigned conditions and operate their jobs through the cooperation with each other. In the DARS, a robot contains sensor part to percept the situation around themselves, communication part to exchange information, and actuator part to do a work. Especially, in order to cooperate with other robots, communicating with other robots is one of the essential elements. Because Bluetooth has many advantages such as low power consumption, small size module package, and various standard protocols, Bluetooth is rated as one of the efficient communicating technologies which can apply to small-sized robot system. In this paper, we will develop Bluetooth communicating system for autonomous robots such as DARS robots. For this purpose, The Bluetooth communication system must have several features. The first, this system should be separated from other robot parts and operate spontaneously and independently. In other words, this communication system should have the ability to organize and maintain and reorganize a network scheme. The next, this system had better support any kinds of standard interfaces in order to guarantee flexible applicability to other embedded system. We will discuss how to construct and what kind of procedure to develop the network system.

• 정보교육학회논문지
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• 제2권2호
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• pp.189-200
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• 1998

웹의 교육적 활용은 학생의 흥미 유발 및 자발적 참여와 아울러 시공간의 제약을 넘어 최신의 정보를 얻을 수 있다는 장점으로 최근 교육 기관으로부터 많은 관심을 끌고 있다. 웹의 자료를 검색하여 원하는 정보를 찾아 교육에 활용하기 위한 연구가 다방변에서 진행되고 있다. 웹 자료의 단순한 활용에서 한 차원 높여 보다 조직적이고 통합적인 웹 기반 프로젝트에 대해 소개한다. 웹 기반 프로젝트의 특징은 프로젝트의 주제에 대한 폭 넓은 경험, 통합 교과교육, 창의성 개발, 협동심 배양, 세계화 교육 등을 꼽을 수 있다. 본 논문은 웹을 기반으로하는 프로젝트의 운영에 대한 개념을 설명하고 그 특성을 살려 어떠한 분야에 활용 할 것인지 논의하고 웹 프로젝트 설계의 기본 구조를 제안한다.

• 한국컴퓨터정보학회논문지
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• 제11권6호
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• pp.221-226
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• 2006

Ad Hoc 네트워크는 유선 네트워크와는 달리 이동성이 존재하는 노드들이 무선환경에서 상호 연결되어 네트워크를 구성한다. 이러한 형태는 라우팅과 서비스 운영환경에서 노드들의 단절 현상이 발생한다. 각 노드들의 위치 정보를 파악하면 이러한 현상을 회피하거나 복구할 수 있고, 일반적으로는 GPS를 이용하여 위치 정보를 파악하지만 구축과 관리가 복잡하고 고비용을 필요로 한다. 본 논문에서는 GPS를 사용하지 않고 전체 노드들이 가지고 있는 정보만을 이용하여, 이동 노드들의 전체적인 위치 정보를 나타내는 맵을 구성하는 방식을 제안하고 구현한다. 제안한 방식은 기존 시스템을 소프트웨어적으로 보완하므로 구축과 운영이 간단하고 구축비용을 절감할 수 있다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제11권3호
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• pp.1533-1556
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• 2017

The concept of trust in vehicular ad hoc networks (VANETs) is usually utilized to assess the trustworthiness of the received data as well as that of the sending entities. The quality of safety applications in VANETs largely depends on the trustworthiness of exchanged data. In this paper, we propose a self-organized distributed trust computing framework (DTCF) for VANETs to compute the trustworthiness of each vehicle, in order to filter out malicious nodes and recognize fully trusted nodes. The proposed framework is solely based on the investigation of the direct experience among vehicles without using any recommendation system. A tier-based dissemination technique for data messages is used to filter out non authentic messages and corresponding events before even going farther away from the source of the event. Extensive simulations are conducted using Omnet++/Sumo in order to investigate the efficiency of our framework and the consistency of the computed trust metrics in both urban and highway environments. Despite the high dynamics in such networks, our proposed DTCF is capable of detecting more than 85% of fully trusted vehicles, and filtering out virtually all malicious entities. The resulting average delay to detect malicious vehicles and fraudulent data is showed to be less than 1 second, and the computed trust metrics are shown to be highly consistent throughout the network.

• Child Health Nursing Research
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• 제8권1호
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• pp.110-120
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• 2002

A phenomenological study is conducted to investigate the experience of mothers with very low birth weight. Sample of 8 mothers participate. Seven theme clusters emerge when the formulated meanings were organized into categories. The participants are 8 mothers who gave birth in the general hospital located in Kyunggi-Province and still live there. The data are collected from the intensive interviews on the experience of mothers whose baby is very low birth weight infant. Data collection is through in depth personal interviews two or three times with each mother. On the basis of the meanings of the experience of mothers with very low birth weight infant, the seven essential themes have been obtained Theme 1:Being surprised and perplexed due to the unexpected sudden delivery Theme 2:Experiencing emotional pain such as anxiety, sorrow, fear, confusion and self-blaming caused by a small and feeble baby. Theme 3: Pouring all their time and efforts into the baby under the acute tension Theme 4:Undergoing intolerable difficulties in confronting reality `Theme 5:Raising the special infant into an normal one by themselves Theme 6: Being on the vigilance for their baby even though they can be relieved Theme 7:Finding out a reward for the difficulties they have experienced The results obtained in this study will enable us to comprehensively understand the experience by mothers whose baby is very low birth weight infant and furthermore to provide a new insight which helps baby.

• Child Health Nursing Research
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• 제14권2호
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• pp.176-185
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• 2008

Purpose: The purposes of this study were to investigate extent of backpack use and incidence of musculoskeletal pain, and to identify the relationship between backpack use and musculoskeletal pain. Method: A descriptive correlational study was conducted in one elementary school and one middle school in D city. Participants were 273 children, aged 12-14, who completed a self-administered questionnaire. Body weight, height, and backpack weight of participants were measured. Results: Mean backpack weight was 3.78 Kg and relative backpack weight (RBW) was 7.42%. Of backpack users, 23.8% carried more than 10% of their RBW and 9.2% carried more than 15%. Only 44.3% organized the contents in their backpack correctly. For more than three fourth of the students (76.2%), the bottom of backpack in the standing position drooped more than 10 cm below the waistline, and 46.3% complained of musculoskeletal pain. Use of a waist belt was significantly related to musculoskeletal pain. Conclusions: A considerable proportion of school children were not following guidelines for safe backpack use. Although the relationship between backpack use and musculoskeletal pain in this study was not significant, the fact that 46.3% of the students experienced musculoskeletal pain is very meaningful information. Further research is required to identify the risk factors of musculoskeletal pain among children.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.119-124
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• 2009

In this paper, we propose a novel approach to estimating the real-time moving trajectory of an object is proposed in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the input-output relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.226-231
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• 2002

The present study discusses the results of the controlled precipitation of HgTe nanocrystals in a PbTe semiconductor matrix and demonstrates its effectiveness in producing well-organized and crystallographically aligned semiconductor nanocrystals. Following the similar procedure used in metallic alloys, the semiconductor alloys are treated at 600$^{\circ}C$ for 48 hours, quenched and aged up to 500 hours at 300$^{\circ}C$ and 450$^{\circ}C$ to induce homogeneous nucleation and growth of HgTe nanocrystalline precipitates. Examination of the resulting precipitates using transmission electron microscopy (TEM) and high resolution TEM (HRTEM) reveals that the coherent HgTe precipitates form as thin discs along the {100} habit planes making a crystallographic relation of {100}$\sub$HgTe///{100}$\sub$PbTe/ and [100]$\sub$HgTe///[100]$\sub$PbTe/. It is also found that the nato-disc undergoes a gradual thickening and a faceting under isothermal aging up to 500 hours without any noticeable coarsening. These results, combined with the extreme dimension of the precipitates (4 nm in length and sub-nanometer in thickness) and the simplicity of the formation process, leads to the conclusion that controlled precipitation is an effective method for the preparation of the desirable quantum-dot nanostructures.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 학술대회 논문집 정보 및 제어부문
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• pp.478-480
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• 2005

The AIS(Automatic Identification System) transmits the position of ships and other information to prevent accidents which could occur in the sea. It has to be developed SOTDMA(Self-Organized Time Division Multiple Access) Algorithm which is important on wireless communication method for the AIS because It is based on ITU(International Telecommunication Union) M.1371-1 of the international standard therefore, we need to develop a performance evaluation simulator efficiently to develop and analyze SOTDMA Algorithm. This paper shows the method of designing it. Real ships access The VHF maritime mobile band but in this performance evaluation simulator several ship objects access the shared memory. Real ships are designed as the object and the wireless communication channel is designed as the shared memory. The ships apply for real virtual data which got from assistance hardware and The SOTDMA Algorithm driving state verifies the performance evaluation simulator by IEC(International Electrotechnical commission) 61993-2. After verifying results the performance evaluation simulator is correctly satisfied with IEC 61993-2. So we expect that it helps not only the AIS technology developed but also verify new SOTDMA Algorithm.