• Korean Journal of Construction Engineering and Management
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• v.20 no.3
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• pp.39-45
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• 2019

Crew productivity in the construction industry is an important indicator of soundness and efficiency of work process, since all works in a site are conducted as groups of people. A survey was conducted in order to reveal importance and performance of major management factors affecting crew productivity in road bridge construction site using IPA. As a result of the analysis, it was found that 'Construction equipment' and 'Human resource related' factors among five major-categories are most important but with low performance. Furthermore, from another analysis with 27 factors of sub-categories, it is revealed that factors needed sustained attention are four, namely 'Just-in-time machinery delivery', 'Formation of a crew members', 'Skill of workers', and 'Site control and management', whereas those needed much more improvement are five, such as 'Machinery performance', 'Clearity of Design', 'Clearity of shop drawing', 'Timing of work instruction and approval', and 'Clearity of work instruction'. Findings from this study will enable road agencies as well as road construction experts to enhance crew productivity in a site.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.1
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• pp.10-23
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• 2009

In this paper we propose a novel mobile terminal software architecture supporting energy efficient handover operation in heterogeneous networks. Since the legacy proposals for L3 handover are mostly dependent on IETF Mobile IP which has some problems in movement detection mechanism and no considerations on nested heterogeneous network environment as a result they make serious overload on networks and terminals by performing unnecessary handover in such network environments. The proposed architecture has terminal-oriented network selection and switching architecture where a mobile terminal periodically monitors network status and selects the optimum network, and reduces energy consumption by making L3 handover of Mobile IP to the finally selected network. The network selection method first picks up some candidate networks by considering a terminal speed and power consumption estimation, and determines the final target handover network among the candidates after evaluating multiple factors including QoS required by a terminal, network status, user preference and terminal battery status. Finally we verify the functionality and performance of the energy efficient vertical handover architecture by means of adopting it into a real mobile terminal.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.6
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• pp.207-213
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• 2014

In this paper, we propose Bluetooth based on efficient indoor-emotion-lighting control system. The proposed Bluetooth based on indoor-emotion-lighting control system was designed to be automatically controlled by the motion sensor light and using a Bluetooth module may be controlled to light up or mobile PC, wall pad. In addition, It was designed the LED lighting On/Off control the environment according to Humidity, the temperature, illumination, motion sensors. System based on the bluetooth is automatic control possible using the illumination sensor, and by selecting the desired lighting partial control can be designed. The experimental efficiency results of the proposed indoor-emotion-lighting control system were designed to provide an internal environment adapted to a resident, were able to maximize the energy savings, have reduced power consumption than the traditional simple On/Off control system.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.2135-2139
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• 2007

현재 한국농촌공사에서는 농업용수의 효율적인 관리를 위하여 물관리자동화사업을 시행하고 약 8만ha를 대상으로 418개의 수리시설을 전동화하였다. 물관리자동화사업에서의 물관리는 공급자 위주로서 이미 결정되어진 물의 양을 시기에 따라 적절하게 공급하여 주며 이를 계측하고 제어하기 위한 시설이다. 그러나 현재 실제로 물관리가 일어나는 곳을 말단포장으로서 급수물꼬의 개폐에 따라 농업용수의 공급과 단절이 이루어지고 있다. 이러한 사실에 착안하여 본 연구에서는 급수물꼬를 논의 담수심에 따라 자동으로 개폐시키는 자동물꼬, 논의 담수심과 수로의 유황상황을 체크하여 정보전달을 수행하는 수로수위측정 및 담수심 측정장치, 상기의 논과 수로의 유황정보에 의하여 논에 물을 공급하는 태양광 전동수문, 수로의 수위증감에 따라서 수로의 수압을 일정하게 형성시켜 용수공급을 원활하게 해주며 또 기존의 제수문과는 다르게 항상 수위를 일정하게 유지하면서도 하류방향으로 물을 공급해주는 무동력 자동수문을 개발하여 시스템으로서 구성하여 설치하였다. 현재 담수심 측정 및 수로수위측정장치로부터의 정보전달은 무선으로 하며 이 정보를 기초로 하여 태양광 전동수문의 모터제어부에서 판단을 하여 수문의 개폐를 지시한다. 또한 무동력 자동수문의 경우에는 부력부가 별도로 설치되어 있어서 주수부를 통하여 수로내 수위와 같은 레벨로 물이 유입되고 이를 플로트가 감지하여 수문비 후방에 설치되어 있는 밸런스 웨이트를 제어하여 수문을 개폐한다. 본 무동력 자동수문은 수위를 유지하는 설정수심을 자유로이 변경할 수 있도록 주수부를 개량하였으며 부력부에 오물유입이 되지 않도록 스크린을 주수부의 물유입장소에 설치하였다. 현재까지 시스템의 작동상황에 대한 성능은 양호하다. 다만 향후의 문제점으로서 시스템이 설치된 지역과 설치되지 않은 지역과의 용수사용량을 비교분석하는 작업으로 본 시스템의 경제적 효과 및 효율성을 증명할 필요가 있으며 본 시스템의 실용화시 시스템 사용방안에 대해서는 대규모 평야부와 저수지 지구의 물공급특성이 다르기 때문에 이를 감안한 시스템 구성을 할필요가 있다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.10
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• pp.2080-2089
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• 2015

In 3D video compression, a disparity vector (DV) pointing a corresponding block position in an adjacent view is a key coding tool to exploit statistical correlation in multi-view videos. In this paper, neighboring block-based disparity vector (NBDV) is shown with detail algorithm descriptions and coding performance analysis. The proposed method derives a DV from disparity motion vector information, obtained from spatially and temporally neighboring blocks, and provides a significant coding gain about 20% BD-rate saving in a texture-video-first-coding scheme. The proposed DV derivation method is adopted into the recent 3D video coding standards such as 3D-AVC and 3D-HEVC as the state-of-the-art DV derivation method.

• Economic and Environmental Geology
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• v.36 no.6
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• pp.557-561
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• 2003

It is important to find out a new material having high removal efficiency for the harmful algal blooms because the dispersion of Hwangto in a large amount to the sea water may bring some ecologically unfavorable problems. For this purpose, the efficiency of several natural and synthetic mineral species for the mitigation of algal blooms was measured. The mixing ratio of monominerals and the sea water with 3,000∼5,000 cells/$m\ell$ of Cochlodinium polykrikoides was 10 g/${\ell}$ and the removal ratio was measured by counting the living cells after the dispersion time of 10, 30 and 60 min., respectively. According to the experimental results, the removal ratio by illite, kaolinite, montmonmorillonite, red mud, Na-A type of zeolite ranged 84-92% after 1hr of contact time, which is comparable to that of Hwangto. The size of above monominerals ranged 3∼50${\mu}m$. Meanwhile, the amorphose material and hematite with the size of 50∼100 nm showed excellent removal ratio of more than 99% after 30min. of dispersion. The results of the study showed that the removal ratio was not related to the chemical composition and pH of the minerals applied but to the grain size. The experimental results strongly suggest that the main mitigation mechanism would be the contact and coagulation.

• Korean Journal of Cognitive Science
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• v.2 no.2
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• pp.405-428
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• 1990

Language has a social function to communicate information. Linguists have gradually paid their attention to the function of language since the nineteen sixties, especially to the relationship of form, meaning and the function. The relationship could be more clearly grasped through disciyrse-based analysis than through sentence-based analysis. Many researches were centered on the discourse functional notion of topic. In the early 1970's the subject was defined as the grammatiocalized topic the topic as a discrete single constituent of the clause. In the late 1970's several lingusts including Givon suggerted that the topic was not an atomic, disctete entity, and that the clause could have more than one topic. The purpose of the present study is, following Givon, to study grammatical coding devices of topic and to measure the relative topic continuity/discontinuity of participant argu, ents in Korean narratives. By so doing, I would like to shed some light on effective ways of communicating information. The grammatical coding devices analyzed are the following eight structures: zero-anaphora, personal pronous, demonstrative pronouns, names, noun phrases following demonstratives, noun phrases following possessives, definite noun phrases and indefinite referentials. The narrative studied for the count was taken from the KoreanCIA chief's Testiomny:Revolution and Idol by Hyung Wook Kim. It was chosen because it was assumed that Kim's purpose in the novel was to tell a true story, which would not distort the natural use of language for literary effect. The measures taken in the analysis wre those of 'lookback', 'persistence', ambiguity'. The first of these, 'lookback', is a measure of the size of gap between the previous occurrence of a referent and its current occurence in the clause. The meausure of persistence, which is a measure of the speaker's topocal intent, reflects the topic's importance in the discourse. The third measure is a measure of ambiguity. This is necessary for assessing the disruptive effects that other topics within five previous clauses may have on topic identification. The more other topics are present within five previous clauses, the more difficult is the task of correct identification of a topic. The results of the present study show that the humanness of entities is the most powerful factior in topic continutiy in narrative discourse. The semantic roles of human arguments in narrative discourse tend to be agents or experiences. Since agents and experiences have high topicality in discourse, human entities clearly become clausal or discoursal topics. The results also show that the grammatical devices signal varying degrees of topic continuity discontinuity in continuous discourse. The more continuous a topic argument is, the less it is coded. For example, personal pronouns have the most continutiy and indefinite referentials have the least continutiy. The study strongly shows that topic continuity discontinutiy is controlled not only by grammatical devices available in the language but by socio-cultural factors and writer's intentions.

• Journal of Energy Engineering
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• v.18 no.3
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• pp.163-168
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• 2009

This paper describes the homogeneous charge compression ignition (HCCI) engine for a new concept. HCCI engines are being considered as a future alternative for diesel and gasoline engines. HCCI engines have the potential for high indicated thermal efficiency under part load and very low NOx emissions. The objective of this paper is to clear the effects of exhaust gas recirculation (EGR) rate on the HCCI. For this purpose, a 4-cylinder, compression ignition engine was converted into a HCCI engine This work has been run with propane and butane fuels at a constant speed.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.463-466
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• 2004

본 연구는 조선 LNG선의 탱크를 제작하는 공장의 관리 및 운영을 지원하는 제조실행 시스템(MES : Manufacturing Execution Sys- tem)의 개발에 대한 내용이다. 본 연구대상 공장에는 가공과 조립라인이 있으며, 가공라인에서는 소재를 가공하고, 조립라인에서는 가공된 소재를 가공하고, 조립라인에서는 가공된 소재를 용접으로 최종 조립한다. 본 연구 대상 공장의 주요 관리 및 운영에 대한 관점은 장비의 고장 방지와 효율극대화, 납기 준수 및 최종 용접 후 결함 최소화 등이다. 이에 본 연구에서는 공장을 체계적으로 관리 운영하기 위해 공정관리와 장비관리 기능을 통합한 제조실행 시스템을 개발하였다. 공정관리는 일정계획 수립, 관리에서부터 작업자 배치 및 입${\cdot}$출고 관리 등의 역할을 수행하고, 장비관리는 장비 모니터링, 장비와 작업 이력 데이터 추출 및 집계, 장비보전 관리, 장비별 작업지시 등의 역할을 수행한다. 본 연구의 개발 시스템은 MSSQL Sever 데이터베이스와 Visual Basic, C++ Builder로 개발되었다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.54-55
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• 2017

본 연구는 항만에 설치된 방사선감시기의 검색기능 극대화를 위하여 방사선감시기의 검색환경을 분석하고 물류흐름 관점에서 운영환경 개선방안 도출을 목적으로 한다. 본 연구 목적 달성을 위해 원자력안전위원회에서 제시한 방사선 위험화물의 수입 물동량 분석을 수행하여 방사선감시기 설치 타당성을 확보하였다. 문헌조사와 현장 전문가 인터뷰를 통해 항만의 방사선감시기 설치환경 및 운영에 따른 물류 장애요인을 분석하였다. 또한, 항만 내 방사선감시기 설치가 가능한 위치를 3단계(본선하역작업, 야드 이송 및 적재 작업, 게이트 반출)로 구분하여 각 위치별 장 단점을 분석하고 최적의 감시기 설치 위치를 도출하였다. 연구결과, 감시기 설치 위치 단계별 비용, 물류흐름, 관리 운영적 측면을 고려하였을 때, 게이트 반출 단계가 방사선 감시기 설치를 위한 최적위치로 적합한 것으로 확인하였다. 방사선감시기의 운영최적화 방안으로는 첫째, 반출 게이트 내부의 2차 검색부지 확보를 통해 게이트 통과 전 방사선감시기를 통한 화물 검색이 이루어질 수 있도록 해야 한다. 둘째, 화물인도지시서(Delivery Order: D/O)를 활용한 신속한 화물정보 파악을 통해 물류흐름의 방해요인을 제거 할 수 있음을 알 수 있다.