• International Journal of Naval Architecture and Ocean Engineering
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• 제12권1호
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• pp.440-454
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• 2020

To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC.

• 한국환경복원기술학회지
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• 제21권6호
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• pp.1-13
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• 2018

Mapping radiation heat flux of urban area is essential for urban design and landscape planning. Because controlling urban geometry and generating green space are important urban design strategies for reducing urban heat, urban planner and designer need to recognize the micro urban heat distribution for adequate urban planning. This study suggests a new methodology for mapping urban radiation heat flux in a micro scale considering buildings and trees' shade. For doing that, firstly, we calculate net radiation for each urban surfaces (building, road (not shaded, building shaded, tree shaded), ground (not shaded, building shaded, tree shaded), tree (not shaded, building shaded)). Then, by multiplying the area ratio of surfaces to the net radiation, we can obtain the radiation heat flux in micro-scale. The estimated net radiation results were found to be robust with a $R^2$ of 90%, which indicates a strong explanatory power of the model. The radiation heat flux map for 12h $17^{th}$ August explains that areas under the building and tree have lower net radiation heat flux, indicating that shading is a good strategy for reducing incident radiation. This method can be used for developing thermal friendly urban plan.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.311-321
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• 2022

In the buildings with long spans and high floors, such as logistics warehouses and semiconductor factories, it is difficult to install supporting posts under beams during construction. Therefore, the size of structural members becomes larger inevitably, resulting in a significant increase in construction costs. Accordingly, a prestressed hybrid wide flange (PHWF) beam with hollowed steel webs was developed, which can reduce construction costs by making multiple openings in the web of the steel member embedded in concrete. However, since multiple openings exist and prestress is introduced only into the bottom flange concrete, it is necessary to identify the shear resistance mechanism of the PHWF beam. This study presents experimental shear tests of PHWF beams with hollowed steel webs. Four PHWF beams with cast-in-place (CIP) concrete were fabricated, with key variables being the width and spacing of the steel webs embedded in the concrete and the presence of shear reinforcing bars, and web-shear tests were conducted. The shear behavior of the PHWF beam, including crack patterns, strain behavior of steel webs, and composite action between the prestressed bottom flange and CIP concrete, were measured and analyzed comprehensively. The test results showed that the steel web resists external shear forces through shear deformation when its width is sufficiently large, but as its width decreased, it exerted its shear contribution through normal deformation in a manner similar to that of shear reinforcing bars. In addition, it was found that stirrups placed on the cross section where the steel web does not exist contribute to improving the shear strength and deformation capacity of the member. Based on the shear behavior of the specimens, a straightforward calculation method was proposed to estimate the web-shear strength of PHWF beams with CIP concrete, and it provided a good estimation of the shear strength of PHWF beams, more accurate than the existing code equations.

• Architectural research
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• 제19권2호
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• pp.35-43
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• 2017

In South Korea, problems such as low fertility, aging population, and income polarization have recently become more serious. In this time of social change, it is necessary to examine the current changes occurring to residences in order to improve the stability and health of residential areas. The purpose of this study is to investigate the changes of residential areas that occurred between 2000 and 2010 based on detached houses, which are the foundation of residential areas in Seoul. Changes in residential areas can be observed by examining changes in the type of housing and the characteristics of the residents. Since the type of housing and the characteristics of the residents change in the same area, it is necessary to study them together, not as individual elements. Census data is suitable for this purpose, because it can show the changes that have occurred to the housing type and the residents' characteristics within the neighborhood unit. Among the census output areas identified as residential areas based on detached houses, six sites were selected as the case study area based on the rate of change of detached houses. From the result of the case study using the census data, the study area was categorized into three regional types: (i) an urban development and redevelopment area; (ii) an area with a concentration or increasing number of detached houses; (iii) an area with an increasing number of multi-family houses based on detached houses.

• 한국BIM학회 논문집
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• 제7권3호
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• pp.21-30
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• 2017

In order to meet current AEC(Architecture, Engineering, Construction) industrial demand, BIM related NCS(National Competency Standards)'s study module in architectural design and construction has been created and it has been applied into the NCS-based curriculum of Specialized High Schools and Meister High Schools from March 2016. Therefore, the goal of this study is to identify the limitations BIM education in the Specialized High School and to find out the improvement plan for activation. Analysis of previous research literature and current education curriculums in the Specialized High School, and questionnaire survey of related teachers have been conducted. Finally, this paper investigated the case of BIM education in 'S' Technical High School where BIM education is carried out. This paper suggests the following three points in conclusion: 1) Updated curriculum reflecting NCS and industrial demand is necessary, 2) Continuing BIM education for teachers and financial support is necessary to get the qualified teaching capacity, 3) Curriculum reflecting BIM's possibilities needs to be developed across the interdisciplinary subjects to maximize its effect.

• Journal of Computing Science and Engineering
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• 제6권1호
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• pp.67-78
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• 2012

People are willing to spend more for their health. Traditional medical services are hospital-centric and patients obtain their treatments mainly at the clinics or hospitals. As people age, more medical services are needed to exceed the potentials of this hospital-centric service model. In this paper, we present the design and implementation of CardioSentinal, a 24-hour heart care and monitoring system. CardioSentinal is designed for in-home and daily medical services. It mainly focuses on the outpatients and elderly. CardioSentinal is an interdisciplinary system that integrates recent advances in many fields such as bio-sensors, small-range wireless communications, pervasive computing, cellular networks and modern data centers. We conducted numerous clinic trials for CardioSentinal. Experimental results show that the sensitivity and accuracy are quite high. It is not as good as the professional measurements in hospital due to harsh environments but the system provides valuable information for heart diseases with low-cost and extreme convenience. Some early experiences and lessons in the work will also be reported.

• 로봇학회논문지
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• 제11권4호
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• pp.256-261
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• 2016

An insect-like flapping-wing flying-robot should be able to produce flight forces and control moments at the same time only by flapping wings, because there is no control surface at tail just like an insect. In this paper, design principles for the flapping mechanism and control moment generator are briefly explained, characteristics measured force and moment generations of the robot are presented, and finally controlled flight of the flying robot is demonstrated. The present insect-like robot comprises a lightweight flapping mechanism that can produce a flapping angle larger than $180^{\circ}$ and a control moment generator that produces pitch, roll, and yaw moments by adjusting location of the trailing edges at the wing roots. The measured force and moment data show that the control input angles less than $9^{\circ}$ would not significantly reduce the vertical force generation. It is also observed that the pitch, roll, and yaw control moments are produced only by the corresponding control input. The simple PID control theory is used for the controlled flight of the flying robot, controlling pitch, roll, and yaw motions. The flying robot successfully demonstrated controlled flight for about 40 seconds.

• 국제초고층학회논문집
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• 제2권4호
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• pp.293-314
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• 2013

Double-Skin Façade (DSF), which is a kind of passive indoor environmental control technique, is effective way to control environmental loads while maintaining the transparency especially in perimeter zone and hence the adoption example of DSF keep increasing recently. The objective of this study was to perform a field survey of air quality environment with natural ventilation through DSF and thermal environment within office building with six stories during a mild climate period in Japan. Moreover, to understand the comprehensive environmental performance of the target building, questionnaire survey was conducted to subjectively evaluate the productivity and satisfaction with the environmental factors in office space. In this field measurement, there was a positive correlation between the DSF internal ventilation flow and the amount of solar radiation on the DSF normal surface; the primary driving force for ventilation in the DSF was considered to be the buoyancy force caused by solar radiation. The results of questionnaire survey with regard to productivity level indicated the need for improvement in the thermal (temperature) and spatial environment (room size and furniture placement).

• 한국정보과학회 언어공학연구회:학술대회논문집(한글 및 한국어 정보처리)
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• 한국정보과학회언어공학연구회 2006년도 제18회 한글 및 한국어 정보처리 학술대회
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• pp.262-267
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• 2006

대화 인터페이스 시스템(dialogue interface system)은 인간과 컴퓨터의 상호작용을 위한 도구로서 자연언어(natural language)를 사용하여 정보를 공유하거나 특정 업무를 수행하는 프로그램이다. 대화 인터페이스 시스템에 대한 기존의 연구들은 영역 의존적인 스크립트나 계획 추론을 위한 계획 지식을 이용해 왔다. 스크립트 모델(script model)은 제한적인 실용시스템 개발을 위해 주로 연구되었고 계획에 기반한 모델은 대화의 원리를 이해하는 분야에서 주로 연구되어 왔다. 그러나 기존의 모델들은 시스템 확장이 매우 어려우며 예측하지 못한 사용자 발화에 대하여 대응이 어렵기 때문에 매우 제한적인 영역이나 정해진 형태의 대화만을 처리할 수 있다. 본 논문에서는 이런 단점들을 보완하기 위하여 통계에 기반한 다 영역(multi-domain) 대화 모델을 제안한다. 제안된 시스템은 각 작업들에 대하여 해당 작업에 적합한 영역 모델(domain model)을 잘 알려진 프레임 구조를 따르면서 사용자 의도 파악과 시스템 의도 생성에 통계적 방법을 사용한다. 이러한 하이브리드 형태의 구조 덕분에 제안된 시스템은 영역 확장성과 이식성이 뛰어나다는 장점을 가진다.

• 상하수도학회지
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• 제33권1호
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• pp.43-53
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• 2019

In the Geumho River, 4-nitrophenol has been detected, thus it is necessary to investigate the contamination sources in order to prevent the release of this compound. However, the research to estimate the potential source is regarded as complicated research. In this study, the distributions of 4-nitrophenol were simulated and the contribution of the potential sources was estimated using a numerical model(HydroGeoSphere; HGS) and the measuring data of 4-nitrophenol from 2013 to 2017. The altitude data, the land cover data, the flow rates of the tributaries and wastewater treatment plants, and the decay rate of 4-nitrophenol was used as the input data. The results of this research showed that the contribution rates of potential contamination sources in the upstream area were higher than that of the downstream area. Most of the upstream area is the agricultural area, it seemed that 4-nitrophenol was originated from the pesticides. In order to achieve more specific location of sources, an intensive investigation in the upstream is required.