• 해양환경안전학회지
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• 제24권2호
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• pp.253-259
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• 2018

2014년 2월 여객선의 타두재 상단 너트가 풀려 타가 작동하지 않은 사고가 발생하였다. 많은 여객과 화물의 이동을 목적으로 하는 여객선의 조타 장치 사고로 인한 인명사고는 통계에 의하면 2010~2016년 0명이지만 조타장치의 고장으로 선박의 요건인 이동성을 갖추지 못한다면 물살이 거센 해역이나 출입항 선박이 많은 협수로에서는 선박의 조종에 대한 제약으로 인명사고의 비율이 높은 전복 사고나 충돌 사고로 발전할 수 있다. "선박안전법" 및 관련 고시인 "강선의구조기준"에는 타판과 타심재의 체결에 관련된 내용은 기준화 되어있으나 타 빠짐의 원인이 되는 상부 타두재와 너트의 체결에 대해서는 별도의 법령이 없다. 사고 이후 한국선급은 강선규칙 5편 제7장에 결합방법에 대해 개정을 하였다. 목포항과 주변 섬을 운항하는 여객선 12척에 대한 현장조사 결과 대부분 C형타 2개가 설치된 구조였으며, 체결방법으로는 9척이 용접에 의한 체결 방법을 적용하고 있었고 선박 자체적으로 예방 점검을 위해 체결 개소에 접근하기 어려운 구조로 되어 있었다. 1년에 한 번씩 타를 들어 올리거나 빼내야 하는 여객선의 특성을 고려하여 동종 사고를 방지할 수 있는 방안에 대해서 NAS 3350 시험을 통해 검토하였다.

• International Journal of Control, Automation, and Systems
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• 제3권2호
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• pp.183-194
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• 2005

In this study, we introduce an advanced architecture of genetically optimized Hybrid Fuzzy Neural Networks (gHFNN) and develop a comprehensive design methodology supporting their construction. A series of numeric experiments is included to illustrate the performance of the networks. The construction of gHFNN exploits fundamental technologies of Computational Intelligence (CI), namely fuzzy sets, neural networks, and genetic algorithms (GAs). The architecture of the gHFNNs results from a synergistic usage of the genetic optimization-driven hybrid system generated by combining Fuzzy Neural Networks (FNN) with Polynomial Neural Networks (PNN). In this tandem, a FNN supports the formation of the premise part of the rule-based structure of the gHFNN. The consequence part of the gHFNN is designed using PNNs. We distinguish between two types of the linear fuzzy inference rule-based FNN structures showing how this taxonomy depends upon the type of a fuzzy partition of input variables. As to the consequence part of the gHFNN, the development of the PNN dwells on two general optimization mechanisms: the structural optimization is realized via GAs whereas in case of the parametric optimization we proceed with a standard least square method-based learning. To evaluate the performance of the gHFNN, the models are experimented with a representative numerical example. A comparative analysis demonstrates that the proposed gHFNN come with higher accuracy as well as superb predictive capabilities when comparing with other neurofuzzy models.

• Structural Engineering and Mechanics
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• 제63권6호
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• pp.713-723
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• 2017

As a new type of ballastless track, longitudinal continuous slab track (CST) has been widely used in China. It can partly isolate the interaction between the ballastless track and the bridge and thus the rail expansion device would be unnecessary. Compared with the traditional track, CST is composed of multi layers of continuous structures and various connecting components. In order to investigate the performance of CST on a long-span bridge, the spatial finite element model considering each layer of the CST structure, connecting components, bridge, and subgrade is established and verified according to the theory of beam-rail interaction. The nonlinear resistance of materials between multilayer track structures is measured by experiments, while the temperature gradients of the bridge and CST are based on the long-term measured data. This study compares the force distribution rules of ballasted track and CST as respectively applied to a long span bridge. The effects of different damage conditions on CST structures are also discussed. The results show that the additional rail stress is small and the CST structure has a high safety factor under the measured temperature load. The rail expansion device can be cancelled when CST is adopted on the long span bridge. Beam end rotation caused by temperature gradient and vertical load will have a significant effect on the rail stress of CST. The additional flexure stress should be considered with the additional expansion stress simultaneously when the rail stress of CST requires to be checked. Both the maximum sliding friction coefficient of sliding layer and cracking condition of concrete plate should be considered to decide the arrangement of connecting components and the ultimate expansion span of the bridge when adopting CST.

• 대한조선학회논문집
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• 제43권5호
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• pp.604-610
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• 2006

Common structural rules of JBP(Joint Bulker Project) and JTP(Joint Tanker Project), which will come into effect in 2006, invoke the necessity of the ultimate limit state(ULS) design for ship structures. Even though the many applications of ULS analysis have been performed for ship structures, there have few studies carried out for deck machineries and their supporting structures. Recently four major Korean shipbuilders(DSME, HHI, HHIC, SHI) jointly developed and proposed a new design standards for mooring fittings and also proposed the SWL (Safety Working Load) obtained based on the first yield criterion. In this study, various ultimate strength analyses were performed for bollards and their foundation structures whose yield strengths were quantified by the research consortium. Prior to performing the ultimate strength analyses, the numerical calculation method was substantiated with the test results provided in the joint work report. Based upon the results of this study, it can be concluded that the reinforcements to increase the yield strength are not always resulted in the enhancement of the ultimate strength. Furthermore, the additional production costs for the reinforcements can not be rewarded by the ultimate strength. Therefore, another alternative arrangements should be developed in the view point of ultimate strength.

• 대한조선학회논문집
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• 제35권2호
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• pp.63-73
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• 1998

최근 산적화물선의 빈번한 침몰사고 발생과 함께 산적화물선의 구조안전성 확보문제가 관심의 대상이 되고 있으며, IMO, 각국 선급협회를 중심으로 구조강도 강화작업이 진행되고 있다. 특히 IMO에서는 산적화물선 침몰사고의 주요 원인중의 하나로 지적되어 온 침수시 파형 횡격벽의 붕괴문제를 방지하기 위해 신조선박뿐만 아니라 기존선박에 대해서도 파형 횡격벽을 보강하도록 하는 규정의 제정을 서두르고 있다. 이 문제와 관련하여 보다 근본적으로는 파형 횡격벽의 최종붕괴 강도 평가방법이 확립되어 있지 않은 문제점이 있다. 본 연구에서는 탄소성 대변형 유한요소 해석기법을 적용하여 파형 횡격벽의 붕괴강도를 계산하기 위한 전용 프로그램을 개발하였으며, 구조모형실험 결과와의 비교를 통하여 개발한 프로그램의 정도와 유용성을 검증하였다.

• 한국수학사학회지
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• 제25권3호
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• pp.29-39
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• 2012

선형논리는 현대 증명이론의 산물로서 1987년 프랑스 Marseille대학 Jean-Yves Girard 교수가 프로그래밍 언어의 개발을 위해 직관주의 논리학 (Intuitional logic) 을 정교하게 보완하여 고안한 새로운 논리학이다. 그래서 선형논리의 연결사들은 정보배열 (Sequentiality)과 병행처리 (Parallel computation) 등 정보처리와 관련된 해석을 갖는다. 예컨대, A${\otimes}$B는 두 과정 A와 B를 차례차례 수행하는 것을 나타내고, A&B는 내적미결정과 관련되어 관찰자가 A 또는 B를 선택할 수 있으며, A${\oplus}$B는 외적인 미결정으로서, 관찰자는 A 또는 B라는 사실을 알지만 어느 것이 될지는 알지 못한다. 그리고 A${\wp}$B는 A과정과 B과정의 병행처리를 의미한다. 선형부정은 동시화(Synchronization)를 나타내어, 하나의 과정 A가 수행되기 위해서는 A와 $A^{\bot}$가 동시에 이루어져야 한다. 국내에 선형논리에 대한 연구가 활성화되지 않아서 이 글은 이에 대한 관심을 제고하기 위해 우선 선형논리의 통사론만을 취급했으며, 의미론과 증명망 등은 차후의 연구에서 다루고자 한다.

• 한국콘텐츠학회논문지
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• 제6권4호
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• pp.109-116
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• 2006

영웅스토리텔링의 기초인 '비범한 탄생', '낯선 세계로의 이입', '탐험, 모험', '영웅의 탄생', '귀환'의 순서는 게임 스토리텔링에서도 기초가 된다. 특히 이 과정 중 다음 단계로의 진입이 게임에서 Stage가 갖추어야 할 특성중 하나가 된다. 이때 영웅 스토리텔링의 관문이 가져야 할 특성은 크게 1) 외부적 한계 2) 내부적 한계의 극복으로 이루어져 있고 이에 대한 보상의 과정을 거쳐, 내부적 인정, 외부적 인정의 단계를 가지는데, 이것이 게임에서 핵심이 되는 중요한 특성이다. 또한 이 단계가 게임 스토리텔링으로 전이되면 다음과 같다. 1-5단계가 기반적 스토리로, 6-9단계가 게임 진행으로, 10-12는 게임의 규칙이나 장르로 변형된다. 본 논문에서는 게임에 적용 가능한 영웅 스토리텔링의 스토리 시스템화를 위하여, 게임 스토리텔링의 근간을 이루는 것이 영웅 스토리텔링이라는 것을 밝히고, 사례를 분석하여 게임에서의 영웅 스토리텔링의 모델을 도출하였다.

• 한국압력기기공학회 논문집
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• 제16권1호
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• pp.74-83
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• 2020

A number of so-called 'Type IV' cracking was reported to occur at the welded joints of the P91 steel or P92 steel reheat steam piping systems in Korean supercritical thermal power plants. The reheat steam piping systems are subjected to severe thermal and pressure loading conditions of coolant higher than 570℃ and 4MPa, respectively. In this study, piping analyses and design evaluations were conducted for the piping system of a specific thermal plant in Korea and suggestions were made how structural integrity could be improved so that type IV cracks at the welded joints could be prevented. Integrity evaluations were conducted as per ASME B31.1 code with implicit consideration of creep effects which was used in original design of the piping system and as per nuclear-grade RCC-MRx code with explicit consideration of creep effects. Comparisons were made between the evaluation results from the two design rules. Another approach with modification or reduction of the redundant supports in the piping systems was investigated as a tool to mitigate thermal stresses which should essentially contribute to prevention of Type IV cracking without major modification of the existing piping systems. In addition, a post weld heat treatment method and repair weld method which could improve integrity of the welded joint of P91 steel were investigated.

• 복식
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• 제57권9호
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• pp.161-176
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• 2007

The objectives of this study are to select and analyze unpublished wedding dresses in the 19th century, to investigate the design characteristics and making techniques of Victorian wedding dresses, and to examine the correlation between the wedding dress style and the fashion style in those days and the influence of the wedding dress style on contemporary's styles. The materials of this study were 9 wedding dresses owned by the Historical Costume and Textile Collection at the University of Connecticut in USA. The dresses were made during the mid and late Victorian Age. As for silhouette, the bustle style was popular in the 1870s and 1880s, and the hourglass style in the 1890s, and different from contemporary dresses there were no big differences in structural pattern and details between ordinary dresses and wedding dresses. In addition, colored wedding dresses were used until the mid and late Victorian Age, but since the wedding ceremony of Queen Victoria in 1840, white wedding dress was widely accepted and settled as the tradition of today's wedding dresses. While the Western dress style had been basically a one piece style, there appeared simple two piece designs in which the upper garment was separated from the lower one, from the mid Victorian Age. This is considered the reflection of those days' pragmatic social trend in dress style. It seems around 1875 when asymmetric design was first introduced in the Western dress style, which had been mostly symmetric. The asymmetric style that pursued atypical beauty, though not common during the late Victorian Age, shows a change in the typical Western dress style. With regard to dress making techniques, sewing machines were distributed widely during the early Victorian Age but they were not used in all parts of dress. Most of details and trimming works were done manually and some parts were attached and detached by hand sewing. In addition, not like today, there were no generalized rules of making such as the form of closings and composition.

• Asia pacific journal of information systems
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• 제16권4호
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• pp.49-70
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• 2006

In recent, Open markets are booming up rapidly. Open markets are one of the online marketplaces which mainly concentrated on spot transactions of commodities, and are differentiated from integrated internet shopping stores with market participants, trading rules and so on. This study investigated on factors affecting satisfaction with and preference on open markets by comparing open markets with integrated internet shopping stores, and aimed to figure out the reasons why open markets are growing up so rapidly and to forecast the future of open markets. To investigate the factors affecting buyers' satisfaction with and preference on internet shopping channel. I extracted several factors through literature reviews. The factors include the pros (cost saving and time saving), the cons (security concerns and privacy concerns), and decision making support suggested by Simon's research as well. Then, I constructed research model and related research hypotheses. To verify research hypotheses, I conducted field survey targeting on online buyers and analyzed research data using structural equation model. According to data analysis result, open markets have competitive advantages over integrated internet shopping stores with respect to cost saving, time saving, and decision making support. However, online buyers are still concerning privacy issues within open markets. In summary, buyers are considering that open markets are cheaper, faster, and more efficient internet shopping channel, compared with integrated internet shopping stores. However, open markets are required to dedicate to lessen buyers' privacy concerns to rebirth as more satisfying and preferable internet shopping channel and to prosper in the future.