• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.1
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• pp.8-14
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• 2020

According to the statistics provided by Korean Maritime Safety Tribunal for the year 2018, the majority of marine accidents in the past four years have occurred in fishing boats and small-sized boats. Negligent behavior resulting from not looking outside and non-compliance with navigation laws are the primary reasons behind ship collisions. Although safety education and training are reinforced to prevent such accidents, they still occur frequently. Hence, technical methods are continuously being developed to reduce ship collisions caused by human cause. The objective of this study is to reduce ship collisions by employing the WAVE communication system, which has short transmitting and receiving periods that can be incorporated for high-speed small-sized vessels. In this study, the suitability of the communication range was examined, and the appropriate range and timing for avoidance motion were accordingly selected, and a control algorithm based on the same was thereby designed. Consequently normal operation of the collision avoidance system was verified by connecting and simulating the proposed WAVE communication router-controller-steering equipment.

• Korean journal of communication and information
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• v.34
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• pp.275-305
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• 2006

The main research question of this paper is as follows: How can broadcasting both cause the crisis in democratic participation and yet also offer the solution? The contradiction in broadcast localism has never been adequately resolved in spite of regulation at all in practice, in that localism simply cannot account for the diversity of modern life and for the external forces that incorporate local communities into much larger economic and communications network. The concept of locality in local television, however, has been multiplied and enlarged in order to adjust to "time-space compression". Recently the local television have been "interface" combining and negotiating the globalization of media market and the decentralization of political power, the economies of scale and the activation of local democracy, consequently aiming at the horizontal-cooperative network instead of old vertical-dependent one.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.152-157
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• 2005

Hypophosphatemia rickets, also known as Vitamin D-resistant rickets(VDRR) and refractory rickets, is a form of rickets which is resistant to the usual doses of vitamin D. VDRR is characterized by decreased renal tubular reabsorption of inorganic phosphate and is easily diagnosed by a normal blood calcium, hypophosphatemia, and slightly elevated alkaline phosphatase. Clinical features of Hypophosphatemia rickets included lateral bowing deformities of the legs, short stature, scoliosis, and enlargement of wrist and ankles. Dental finding in patient with VDRR were spontaneous dental abscesses in caries free teeth and other dental findings included delayed eruption, delayed apical closure, thin and hypoplastic enamel, absent or poorly defined lamina dura, enlarged pulp chambers, and numerous accessory canals and pulp horns that extend up and into the dentinoenamel junction. we reported the clinical feature and treatment of VDRR child who was referred from the department of pediatrics for early loss of primary teeth and its treatment.

• Journal of the Korean Geographical Society
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• v.39 no.3
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• pp.374-390
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• 2004

This research analyzes the differentiation of the reproduction of the educational capital according to the residential area which is determined by the socio-economic status of parents. The results of the research show that: the reproduction of the educational capital of the region where highly educated people are segregated is very different from that of other regions in terms of the quantity and quality. The fact that one resides in a certain special area tends to determine the future of his child, so the boundary between the social groups is being intensified through the geographic concentration of the affluence and poverty. Gangnam Gu where the different educational capital is reproduced through the better educational environment tends to become the gated city which has the invisible but strong socio-economic barriers through the sharp rise of the housing(apartment) value and the concentration of highly educated people. Through the exclusion of other classes by the high price of the housing, only the residents within the barrier have access to the good educational facilities and services.

• 한국HCI학회:학술대회논문집
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• 2008.02b
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• pp.41-46
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• 2008

디지털 기술의 발전은 인간 생활에 큰 변화를 가져다주었다. 이와 같은 디지털 기술의 발전으로 변화된 인간 생활 중 가장 큰 변화는 기술의 발전 이전에 사용되던 각종 제품 및 도구들이 디지털 기술의 힘으로 새롭게 재탄생하고 있다는 점이다. 재탄생된 제품 및 도구들은 사람과 제품간의 경계를 무너뜨리고 서로 융합되고 있다. 이러한 제품들 중에서 대표적으로 Digital Mirror를 들 수 있다. 기존 인간 생활에서 사용되던 일반적인 Mirror가 최근 들어 Digital Mirror라는 새로운 형태의 제품으로 연구되어 지고 있다. 이러한 Digital Mirror는 일상생활 속에서 기존 거울을 대체하고 있으며, 인터렉티브 미디어 아트에서도 많이 응용되고 있다. 현재 Digital Mirror는 광고, 인터렉티브 아트 등의 분야에서 다양한 형태의 콘텐츠가 개발되고 있다. 하지만 Digital Mirror를 새로운 제품 산업군으로 확대하여 신사업을 창출하기 위해서는 수많음 사용자들의 욕구를 충족시킬 수 있는 인터렉티브한 콘텐츠 제작을 해야 한다. 본 연구에서는 Digital Mirror의 인터렉티브한 콘텐츠 제작을 목적으로, 기존의 인터렉티브한 콘텐츠 사례를 중점적으로 연구하여 새로운 콘텐츠 아이디어를 도출하였다. 아이디어를 통해 어린이 사용자를 타켓으로 새로운 사용경험을 제공해 줄 수 있는 컨셉을 정하여 인기 애니메이션 캐릭터를 사실적으로 체험할 수 있게 해주는 콘텐츠 제작방향을 설정하여 연구를 진행하였다. 또한 놀이와 참여, 상호작용을 통한 새로운 디지털 놀이 도구라는 개념으로 AR기술을 이용해 캐릭터를 좀더 사실적으로 체험 할 수 있도록 제작하였다. 어린이 사용자가 캐릭터 마커를 착용하고 Digital Mirror앞에 서게 되면 캐릭터 마커에 해당되는 3차원 입체영상 애니메이션 캐릭터가 어린이 사용자의 모습과 합성되어 사실적인 캐릭터 콘텐츠를 체험 할 수 있게 해 주는 콘텐츠이다. 어린이들에게 인기 있는 캐릭터를 3D로 제작하여 캐릭터 소스로 활용하였고 이를 효율적으로 사용할 수 있도록 어플리케이션 저작툴을 개발 완료하여 제작하였다. 그리고 평판 디스플레이를 이용하여 실제 Prototype 제작하였다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.5
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• pp.553-560
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• 2015

Fracture mechanics analysis for cracked pipes is essential for applying the leak-before-break (LBB) concept to nuclear piping design. For LBB assessment, crack instability and leak rate should be predicted accurately for through-wall cracked pipes. In a nuclear piping system, elbows are connected with straight pipes by circumferential welding; this weld region is often considered a critical location. Hence, accurate crack assessment is necessary for cracks in the interface between elbows and straight pipes. In this study, the stress intensity factor (SIF) and elastic crack opening displacement (COD) were estimated through detailed 3D elastic finite element (FE) analyses. Based on the results, closed-form solutions of shape factors for calculating the SIFs and elastic CODs were proposed for circumferential through-wall cracks in the abovementioned interfaces under internal pressure. In addition, the effect of the elbow on shape factors was investigated by comparing the results with the existing solutions for a straight pipe.

• The Transactions of the Korea Information Processing Society
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• v.6 no.6
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• pp.1635-1645
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• 1999

In this paper, an intelligent resynthesis technique for timing optimization at the architecture-level has been studied. The proposed technique can remedy the problem which may occur in combinational timing optimization techniques applied to circuits which have the hierarchical subblock structure at the architectural-level. The approach first tries to maintain the original hierarchical subblock while minimizing the longest delay of whole circuit. This paper tries to find a new approach to timing optimization for circuits which have hierarchical structure at architectural-level, and has verified its effectiveness experimentally. We claim its usefulness from the fact that most designers design the circuits hierarchically due to the increase of design complexity.

• Journal of the Korean Society for Library and Information Science
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• v.36 no.3
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• pp.115-132
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• 2002

This study is an examination of knowledge-based society's impact on knowledge, it's functions, and it's types in fields of humanities an social sciences. Knowledge-based society does not invalidate the definitive mechanism underpinning social coexistence today, but the importance of knowledge will increase greatly whereas the importance of the productive resources labor and capital will diminish. Therefore, knowledge-based society demands that we enter at this time into a discussion that takes new approaches to the knowledge. This study provides a doorway to a discussion of topics such as : Anticipating and characterizing the knowledge-based society, spectrum of fields of new types of knowledge for which typical differences can be ascertained, the interlinking of various disciplines in the respective field of knowledge, the new roles and types of knowledge in the fields of humanities and social sciences.

• Fire Science and Engineering
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• v.14 no.3
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• pp.1-5
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• 2000

In this paper, we analyzed the fire hazard of the ballast for fluorescent lamp used as the indoor lighting. In the result of being analyzed the ballast wire by stereo microscope, many melting points were discovered, it was impossible to judge a cause with the naked eye. In the Thermal-deteriorated ballast wire, elongation structure disappeared at above $700^{\circ}$, and it only showed the enlarged appearance of the copper particle. On the metallurgical microscope of short wire, as it was confirmed the regulation of the columnar structure and the void growth at the center of boundary-face, we found that electrical short-circuit generated. Also, it was confirmed the melted part on the analysis using SEM(scanning electron microscope). Not only CuL and Cuk line that is composition factor of copper but also OK line was observed uniformly on the spectra analysis using EDX(energy dispersive x-ray spectroscopy). It means that oxygen took part in reaction at the recombination process.

• Convergence Security Journal
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• v.20 no.3
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• pp.13-20
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• 2020

Recently, the need of researches and developments about WSN(Wireless Sensor Network) technologies, which can be applied to services that require continuous monitoring or services to specific areas where accesses are limited, has gradually increased due to their expansion of application areas and the improvement of the efficiency. Especially, in the defense field, researches on the latest IT technologies including sensor network areas are actively conducted as an alternative to avoid the risk factors that can be occurred when personnel are put in, such as boundary and surveillance reconnaissance and to utilize personnel efficiently. In this paper, we analyze the conditions for increasing the life span of sensing nodes that make up sensor network by applying clustering and location-based techniques and derived the factors for extending the life span of them. The derived factors include CH(Cluster Head) election scheme and optimal path selection from CH to BS(Base Station). We proposed final scheme using derived factors and verified it through simulation experiments.