• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.5
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• pp.448-454
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• 2008

This paper deals with a behavior based decentralized control strategy for UAV swarming utilizing the artificial potential functions and the sliding mode control technique. Individual interactions for swarming behavior are modeled using the artificial potential functions. The motion of individual UAV is directed toward the negative gradient of the combined potential. For tracking the reference trajectory of UAV swarming, a swarming center is considered as the object of control. The sliding-mode control technique is adopted to make the proposed swarm control strategy robust with respect to the system uncertainties and the varying mission environment. Numerical simulation is performed to verify the performance of the proposed controller.

• Journal of the Korean Society for Precision Engineering
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• v.4 no.4
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• pp.1-5
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• 1987

어떤 산업이든 기계공업이 관여되지 않는 분야가 없듯이 공작기게가 관여되지 않는 기계공업은 생각할 수 없다. 이와같이 공작기계는 <기계를 만드는 기계> 라는 점에서 모든 산업분야의 근간을 형성하고 있으므로 공작기계의 품질과 성능은 곧 한나라의 기술수준을 가늠하는 척도로서 대표된다고 하여도 과언은 아 니다. 오늘날 선진국들은 수요자가 요구하는 다양한 초정밀공작기계까지도 만들고 있다. 크게는 우주개발에 서 항공기, 선박 및 자동차생산을 위시하여 건설장비, 전자 및 광학, 정밀화학, 각종 시험기기 등 공작기계의 손이 미치지 않은 곳이 없다. 이렇게 공작기계는 전산업에 걸쳐 크게 영향을 주고 있으며, 특히 최근의 산업 화 추세가 점차 자동화, 무인화, 초정밀첨단산업으로 비약함에 따라 공작기계의 역할은 더욱더 중요시되고 있 다. 우리나라 공작기계공업은 1960 년대의 이전 극히 영세한 중소기업중심의 보수공작기계부품 생산형태에서 1960 년대 후반부터 일부 범용기종의 생산이 시작되었으나 보다 본격화한 것은 1973 년 정부의 중화학공업육성 시책에 따라 대기업의 대거 참여로 공작기계제조업은 시설, 자산, 경영면에서 대형화 하였고, 동시에 선진국의 최신기술과 시설을 적기에 도입하므로써 품질향상, 신제품개발, 수출참여 등 공작기계공업 발전에 일대 전기를 마련하였다. 특히 '85 년에 들어서면서부터 3 저의 여파로 국내 자동차산업의 호황, 전자, 기계 및 관련수요 산업의 설비투자와 시설개체에 힘입어 공작기계생산도 활발하기 시작하여 그 어느때보다 생산기반혁신을 위한 구조적 대응책이 절실해지고 있다. 따라서 공작기계공업의 당면과제는 지속적인 기술개발과 품질향상으로 국산 화율을 제고시켜야 함은 물론, 이를 양산화하여 명실공히 선도산업으로서의 위치를 굳히고, 적어도 기계류의 수입국에서 기계류의 수출국으로 기치를 든 탈바꿈을 할때 비로소 불균형이 없는 흑자시대는 도래할 것이다.

• Journal of the Korea Computer Graphics Society
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• v.21 no.2
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• pp.1-10
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• 2015

In this paper, we propose an improved surface reconstruction method from an oriented point cloud. Our method is a classical least-square scheme, but is based on the 7-direction box-spline and the BCC (Body-Centered Cubic) lattice, which results in surfaces with superior quality and lower computational overhead, compared to other methods based on the B-splines on the Cartesian lattice. Specifically, when compared with two of the most popular techniques our method results in better surfaces but only takes ${\approx}53%$ computation time.

• The KIPS Transactions:PartD
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• v.10D no.4
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• pp.689-696
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• 2003

Criticality prediction models that determine whether a design entity is fault-prone or non fault-prone are used for identifying trouble spots of software system in analysis or design phases. Many criticality prediction models for identifying fault-prone modules using complexity metrics have been suggested. But most of them need training data set. Unfortunately very few organizations have their own training data. To solve this problem, this paper builds a new prediction model, KSM, based on Kohonen SOM neural networks. KSM is implemented and compared with a well-known prediction model, BackPropagation neural network Model (BPM), considering internal characteristics, utilization cost and accuracy of prediction. As a result, this paper shows that KSM has comparative performance with BPM.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.47 no.4
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• pp.419-427
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• 2011

Simulation technique for the fish behavior was applied to estimate fish school movement in the cage net. Individual-based fish behavior model (Huth and Wessel, 1991) was evaluated in a free area to understand the characteristics for the model, and the movement in the cage net was simulated by defining the fish reaction against the displacement of cage net. As a result, the distance to the net was not considerably changed and the space among fishes in cage net was slightly decreased by reducing the net space. Swimming area was, however, significantly affected by changing the net space and the relationship between swimming area and net displacement was theoretically estimated as y=-0.21x+1.02 ($R^2$=0.96). these results leads the conclusion that individual-based model was appropriated to describe the fish school reaction in the cage net and be able to use for evaluating the influence on cultured fish.

• Journal of Korean Library and Information Science Society
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• v.36 no.1
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• pp.459-477
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• 2005

The purpose of this study is to investigate a fundamental model for categories and relationships among concepts in library and information science field in order to construct an ontology based upon the knowledge construct of human being. Questionnaire and interview were involved for this study, The results shows that students' knowledge structure was different from KDC and DDC schemes. Students had an object oriented knowledge structure and provided four relationship models. These model could provide a fundamental data for ontology construction. Also, it shows that student academic grades influenced their knowledge structures.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.35-35
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• 2001

본 연구는 수정란이식기법에 의해 우량 한우 송아지를 대량 생산할 수 있는 기반조성을 위한 한우 수정란이식 최적모델을 개발하기 위해 실시되었다. 본 시험에 공시된 수정란은 우량한 한우의 체내수정란 및 체외수정란을 생산하여 좋은 배반포 수정란을 신선 혹은 동결란 상태로 이식에 공시하였다. 수란우는 정상 발정주기를 가진 경산우로 CIDR을 이용하여 발정을 동기화 하였고 이식시 직장검사로 황체의 크기를 검사하고 초음파진단기로 황체의 구조를 조사하여 정상인 개체에 수정란을 이식하였다. 수란우의 최적 선정조건을 구명하고자 혈중 호르몬 및 대사물질을 분석하였으며 얻어진 결과는 다음과 같다. 1. 총 397두의 수란우에 수정란을 이식하여 121두가 임신하여 평균 30.5%의 수태율을 얻었다. 2. 수란우의 황체의 크기 및 황체내 강 형성 유무와 수태율간에는 차이가 없었으나 혈중 progesterone 수준을 분석해 본 결과, progesterone 수준이 2.0 ng/$m\ell$ 이상일 경우 수태율이 46.6%로 높게 나타났다. 3. 수란우의 혈중 Total cholesterol은 90~110mg/㎗, BUN은 14~16 mg/㎗, Glucose 수준은 70~80 mg/㎗에서 가장 높은 수태율을 나타내어 이들 혈중 대사물질이 수태율에 영향을 미치는 것으로 나타났다.

• The Journal of Korea Robotics Society
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• v.6 no.1
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• pp.1-9
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• 2011

An increasing number of researches and developments for personal or professional service robots are attracting a lot of attention and interest industrially and academically during the past decade. Furthermore, the development of intelligent robots is intensively fostered as strategic industry. Until now, most of practical and commercial service robots are worked by remotely operated controller. The most important technical issue of remote control is a wireless communication, especially in the indoor and unstructured environments where communication infrastructures might be destroyed by various disasters. Therefore we propose a multi-robot following navigation method for securing the valid communication distance extension of the remote control based on WPAN(Wireless Personal Area Networks). The concept and implementation of following navigation are introduced and the performance verification is performed through real navigation experiments in real or test-bed environments.

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.129-151
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• 2017

Information modeling that is broadly applied in digital archiving process privides conceptual process that can be used to guide the creation of descriptions for the objects of preservation. However, it has faced with the limitations on substantially applying to the creation of preservation metadata records. This research proposes the concept of Resource Cluster in order to address these problems and efficiently describe the objects of preservation during digital archiving process. It also constructed Preservation Description Framework (PDF) based on RDF in order to substantially manifest preservation descriptions. This framework combines the structure of OAIS Reference Model and Functional Requirements for Bibliographic Records (FRBR) and can be an alternative approach to the creation of preservation metadata in more efficient and effective ways.

• Journal of Korea Multimedia Society
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• v.3 no.5
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• pp.470-478
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• 2000

Color images from various application areas have their own characteristics. Practical segmentation systems need specialized methods to death with the characteristics. In this paper. we propose a distributed genetic algorithm based segmentation method for color breast carcinoma cell images. To extract positive nuclei and negative nuclei from the cell images, a distributed genetic algorithm with improved genetic operations and an evaluation function is used. As initial values, representative colors from images are introduced to work well with the cell images. A test to verify the validity of the proposed method shows well-segmented images. This result suggests that the method is pertinent to be but into practical use for the images haying limited objects with limited colors.