• 한국지반공학회논문집
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• 제24권7호
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• pp.25-36
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• 2008

평면변형률 시험기는 실제 지반의 파괴 거동을 보다 근사하게 모사할 수 있다는 장점 때문에 평면변형률 조건을 구현하려는 목적 외에도 흙의 국부적인 변형을 포함하는 전체적인 파괴거동을 관찰하기 위한 목적으로 활용되고 있다. 그러나 대부분의 평면변형률 시험은 시험기 제작과 시험 수행의 어려움 때문에 바닥판이 고정된 단부 구속하에서 수행되는 경우가 일반적이다. 최대 주응력 면의 단부 구속은 주응력 면에 추가적인 전단응력을 유발시켜 의도된 전단 거동을 저해하므로, 시험 결과가 실제 현장에서 발생하는 전단 거동과 다를 수 있다. 본 연구에서는 바닥판 구속을 제어할 수 있는 평면변형률 시험기를 이용하여 단부 구속 여부에 따른 두 가지 시험을 주문진 표준사에 대하여 수행하였다. 시료의 국부적인 변형을 포함하는 전체적인 거동을 측정하기 위해 외부 LVDT와 함께 디지털 이미지 코릴레이션 기법(DIC)을 적용하였다. 평면변형률 시험기의 투명한 측면판을 통하여 서로 다른 시간에 촬영된 두 개의 디지털 이미지를 본 기법으로 해석하여 응력-변형률 거동과 하중 증가에 따라 나타나는 시료 내부 모든 위치에서의 국부적 변형 거동을 파악하였다. 이로써 단부 구속 여부에 따라 발생하는 평면변형률 조건하에서 사질토의 파괴면 형성과 발달과정 그리고 변형 메커니즘을 규명하였다.

• 전자통신동향분석
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• 제35권6호
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• pp.107-118
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• 2020

The smart city agenda aims to solve various problems arising in cities and promote the welfare and happiness of citizens by utilizing the new technologies of the 4th Industrial Revolution. Smart city policies have been promoted at the national level, but until now, policy implementations have not been effective enough to fundamentally affect citizens. To realize a more realistic and practical smart city, it is necessary to examine the problems occurring in the city in depth and set the direction and tasks of the smart city accordingly. Therefore, this study specifies the issues and problems faced in 12 sectors, including manufacturing, logistics, medical care, and safety. Next, by referring to the existing literature, a future smart city integration model is proposed that can respond to these problems. That is, future smart cities should create detailed services with enhanced efficiency, sustainability, strong risk management, safety, and satisfaction as the main goals. This study is meaningful in that it suggests a vision and tasks of smart cities that can solve problems in various sectors in a form that can be felt by the citizens.

• International Journal of Internet, Broadcasting and Communication
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• 제12권1호
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• pp.130-136
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• 2020

There are many problems that occur currently in agriculture industries. The problems such as unexpected of changing weather condition, lack of labor, dry soil were some of the reasons that may cause the growth of the plants. Condition of the weather in local area is inconsistent due to the global warming effect thus affecting the production of the crops. Furthermore, the loss of farm labor to urban manufacturing jobs is also the problem in this industry. Besides, the condition for the plant like air humidity, air temperature, air quality index, and soil moisture are not being recorded automatically which is more reason for the need of implementation system to monitor the data for future research and development of agriculture industry. As of this, we aim to provide a solution by developing IoT-based platform along with the irrigation for increasing crop quality and productivity in agriculture field. We aim to develop a smart garden system environment which the system is able to auto-monitoring the humidity and temperature of surroundings, air quality and soil moisture. The system also has the capability of automating the irrigation process by analyzing the moisture of soil and the climate condition (like raining). Besides, we aim to develop user-friendly system interface to monitor the data collected from the respective sensor. We adopt an open source hardware to implementation and evaluate this research.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2011년도 제42회 하계학술대회
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• pp.344-345
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• 2011

A necessity to a superconducting cable in power transmission systems have been growing more and more due to high power density in urban areas and rapid increase of power demand. In view of these situation, it is a noteworthy fact that superconducting cable has remarkable advantages, such as lower power loss and 3-5 times higher power transmission capacity, compared with conventional power cable. For the last a few years, long-term reliability tests had been carried out in the KEPCO PT Center, and now it has been installed in KEPCO's real power grid for demonstrating commercial operation. This paper deals with the test results of dielectric properties performed at manufacturing factory for the joint box, termination and core of HTS cable system and whole system connected in real power grid.

• 한국건설관리학회논문집
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• 제5권1호
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• pp.80-87
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• 2004

본 연구에서는 건설 프로젝트에 대한 공급사슬 관리 측면에서의 분석을 통하여, 프로젝트를 구성하는 전반적 구성 요소들에 대한 심층적인 이해와 이의 개선 방안을 다루고 있다. 이러한 건설 공급사슬 관리 차원의 효율성 향상을 도모코자, 본 연구에서는 미국의 일반적인 고층 사무 빌딩 프로젝트에 참여하는 실제 공급사슬 구성원들과의 인터뷰를 통하여, 건설 프로젝트 관리에 대한 공급사슬 관리 맥락에서의 정성적인 분석을 시행하였다. 본 연구는 전기 및 기계 분야 공급사슬을 중심으로 하여, 공급사슬을 구성하는 하도급 업체, 공급자, 제조업체 및 유통업자의 역할을 조사 하였고, 아울러 원도급 업체가 프로젝트 관리 상에 직면할 수 있는 문제점들에 대하여도 파악하였다. 이를 토대로 본 연구에서는 크게 프로세스 재구성(restructuring)과 자동화(automation)라는 개념에 의거한 개선 방안들을 제안하였으며, 인터뷰를 통해 조사된 현황 파악 척도 및 인센티브 제도와의 조율 방안을 제시 하였다.

• 한국식생활문화학회지
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• 제13권2호
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• pp.119-126
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• 1998

This study was carried out to give some help for housewives recognizing the desirable purchase of processed foods and food additives. This results were abtained as follows; In case of purchase action for processed foods of housewives confirmation of manufacturing date was the highest point(4.62). When housewives bought processed foods they considered the taste of them as first, and frequencies of processed foods intake showed the ratio of 46.6%, also it was shown to be used once a week. The order for use of processed foods were milk, milk products(butter, cheese, yoghurt, lactic bacterium beverage) 40.2% >canned foods 22.6% >meat products(ham, sausage, bacon) 20.9% > jelled fish 16.3%. Most of housewives wanted to have the knowledge and information for food additives at the highest point(4.11). The interest about food additives of housewives was shown to the order of synthetic preservative 3.86 >chemical seasoning 3.74 >synthetic sweetener 3.59 >synthetic coloring agent 3.53. Also, it was shown to be thought that the hazard factors effected on food safety were agricultural chemical residue(30.9%), environmental pollution(25.2, food additives(23.0%), and microorganism contamination(20.9%).

• 한국자동차공학회논문집
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• 제10권2호
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• pp.166-173
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• 2002

The wheel bearing hub unit is developed type of wheel bearing unified with the hub parts. It has advantage of reducing the weight and the number of components. And, it also improves uniformity of manufacturing quality, In order to design the wheel bearing hub units, many techniques are used such as load analysis, structure analysis and bearing characteristics analysis and so forth. These techniques need highly accurate load conditions founded on service conditions. In this study, to design the wheel bearing hub units used widespread in passenger cars, the service load was measured through driving tests on the public roads and in the special events. The public roads are classified into highway, intercity road, rural road, urban road, and unpaved road so as to know what the characteristics of the road loads are. The results of the tests showed that the wheel force was relative to the lateral acceleration, and also could be calculated from the lateral acceleration. The lateral acceleration was measured from 0.0G to 0.6G in general driving on the public roads, with different distributions in each road type. In special events, the maximum lateral acceleration was measured from 0.8G to 1.3G.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2006년도 춘계학술논문 발표대회 제6권1호
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• pp.107-110
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• 2006

In this study, recently it is urgently required that recycle promotion of construction and demolition waste concrete because urban development is accelerated and redevelopment project is rapidly expanded, production quantity of construction and demolition waste concrete is being increased. On the other hand, it is urgently required that problem solution of demand and supply unbalance of fine aggregate because the sea sand is restricted by exhaustion of river sand and intensification of environment influence evaluation. Therefore, it tries to conform in time necessity, there is the objective of this study to provide the fundamental data about the re-application as the comparison and analysis the quality present condition for the recycled fine aggregate in the inside and outside of the country. At the same time it will be able to improve the quality of the recycled fine aggregate waste as investigating the physical nature and a quality present condition of the recycled fine aggregate from construction waste.

• 토지주택연구
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• 제10권3호
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• pp.77-87
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• 2019

In Korea, the modular construction method was applied to the construction of facilities such as military barracks and school dormitories, beginning with the pilot project of Seoul New Elementary School in 2003. In 2017, public modular houses were supplied to Busan(Yongho-dong) and Seoul(Gayang-dong), and modular housing is expected to continue to be supplied in the future. However, there is no clear construction standard for the modular housing construction yet, and there are few cases where the infill modular system is applied. Therefore, this study established the work breakdown structure and proposed a standard process focusing on the infill modular system applied to the construction of Dujeong-dong modular house in Cheonan. Level 1 of the work breakdown structure by construction stage of Infill modular was defined as modular manufacturing, assembly, and finishing process. Level 2 was defined as preparation, modular production, modular infill, modular fixing, floor plastering, building finishing, and other site finishing. Level 3 is defined as 57 detailed unit work of infill modular construction. The standard process of infill modular is proposed for the assembly stage that is commonly applicable to infill modular housing construction. The results of this study can be used for the process plan, transportation plan, lifting plan of modular housing construction.

• 한국가구학회지
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• 제23권4호
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• pp.381-387
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• 2012

Utilization of underground floor is becoming the main issue of our society to maximize and diversify the potential of recent urban space. It has brought about the changes of underground floor. Recently there are lots of huge bookstores in these underground floor. Bleach, adhesive and ink used for manufacturing books pollute indoor air in bookstore. Therefore, the purpose of this study is to analyze indoor air quality in these large bookstores. Concentrations of carbon dioxide and formaldehyde in three large bookstores in Seoul were measured by presence and type of books and distance of main entrance which is well-ventilated. According to the data, space that places lots of volumes measured higher concentration of formaldehyde than that of non-existence books. Children's book section was measured more concentration of formaldehyde than other book section. Closer main entrance near outside, lower concentration of formaldehyde was measured. Concentration of carbon dioxide was affected by the number of people in bookstore.