• Structural Engineering and Mechanics
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• 제6권1호
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• pp.77-93
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• 1998

Some design formulas and design procedures for single and multiple tuned liquid column dampers (TLCDs) are proposed in this study. Previous studies show that if the properties of the TLCD system are properly selected then the TLCD could be as effective as the traditional tuned mass dampers. In addition, the TLCD system offers advantages such as flexibility in terms of installation, little maintenance required, and potentials for multiple usage, etc., which are incomparable by other mechanical types of dampers. In this paper, a set of optimal properties such as length and head loss of a TLCD system are derived under the assumption that the building vibrates in a dominate mode and is subjected to Gaussian white noise excitation. A design procedure for a single TLCD system will be illustrated and discussed. Due to the nonlinearity in the damping term, the TLCD system is sensitive to the loading intensity. This loading sensitivity could limit the application range of the TLCD system. It will be shown in this paper that such a nonlinear effect can be reduced by using multiple TLCDs. As a demonstrative example, the control effects on a flexible building modeled as a single degree-of-freedom system subjected to white noise excitation will be analyzed and discussed using single or multiple TLCDs.

• 벤처창업연구
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• 제7권2호
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• pp.63-76
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• 2012

기술혁신제품에 대한 사업화의 성공 여부는 소비자가 제품을 선택하여 이용하는 정도에 달렸다. 따라서 기술혁신제품 사용자의 수용의도와 사용행위에 영향을 미치는 요인에 대한 연구는 매우 중요하다. 본 연구는 기술혁신제품인 클라우드 컴퓨팅을 대상으로 기술혁신제품의 사업화에 영향을 미치는 요인을 제시하고자 하였다. 기존 연구들은 TAM 모형을 확장하면서 태도와 사용행위를 제외하고 수용의도만 검증하였지만, 본 연구에서는 태도와 사용행위 그리고 소비자의 개인적 특성을 중요한 영향요인으로 포함하였다. 연구 결과 첫째, 개인특성의 자기효능감은 지각된 사용용이성과 수용의도에, 지각된 비용은 지각된 유용성과 지각된 사용용이성에 각각 정(+)의 영향 미치는 것으로 나타났다. 둘째, 클라우드 컴퓨팅의 시스템특성인 보안성은 수용의도에, 혁신성은 사용용이성에 정(+)의 영향을 미치는 변수로 확인되었다. 셋째, 사용자들의 활용특성인 지각된 유용성은 수용 및 사용행위에 정(+)의 영향을 미치며, 지각된 사용용이성은 지각된 유용성에 정(+)의 영향을 미치는 것으로 확인되었다. 본 연구는 클라우드 컴퓨팅에 의한 서비스가 대중적으로 확산되지 않은 현시점에서 수용 및 사용행위에의 영향변수를 제시함으로서 정책적 방향 및 사업화 전략에 의미 있는 결과를 제공하였다.

• 한국태양에너지학회 논문집
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• 제36권6호
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• pp.47-59
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• 2016

As the usage of sun tracking system in solar energy utilization facility increases, requirement of more accurate computation of sun position has also been increased. Accordingly, various algorithms to compute the sun position have been proposed in the literature and some of them insist that their algorithms guarantee less than 0.01 degree computational error. However, mostly, the true meaning of accuracy argued in their publication is not clearly explained. In addition to that, they do not clearly state under what condition the accuracy they proposed can be guaranteed. Such ambiguity may induce misunderstanding on the accuracy of the computed sun position and ultimately may make misguided notion on the actual sun tracking system's sun tracking accuracy. This work presents some comments related to the implementation of sun position computational algorithm for the sun tracking system. We first introduce the algorithms proposed in the literature. And then, from sun tracking system user's point of view, we explain the true meaning of accuracy of computed sun position. We also discuss how to select the proper algorithm for the actual implementation. We finally discuss how the input factors used in computation of sun position, like time, position etc, affect the computed sun position accuracy.

• 한국산업정보학회논문지
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• 제22권4호
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• pp.11-18
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• 2017

본 논문은 소비자에게 공급되는 수돗물의 공급시설(Water Supply Network)에 IoT 기술을 활용하여 소비자의 물 사용량을 원격으로 검침하고, 공급시설의 누수를 줄여서 원가를 절감하는 스마트 물관리(Smart Water Management) 기술의 적용효과를 검증하였다. SWM 실증모형은 수돗물 공급시설에 원격 누수감지센서, 스마트 미터링(Smart Metering), 초소형 멀티센서를 설치하고, 원격에서 운영현황을 실시간으로 감시하고 소비자에게 수돗물 사용량과 수질을 스마트폰 앱으로 제공하였다. 이때, 소비자가 수돗물 사용량 정보를 이용하여 수돗물을 아껴 쓰는지, 수돗물 수질정보를 이용하여 직접 음용하는지를 조사하였다. 특히, 본 연구에서는 SWM을 실증 적용함으로써 공급시설의 유수율 향상, 수돗물 음용률 향상, 소비자 민원 감소, 운영비용 절감, 수돗물 사용량 절감이 달성되는지를 검증하는데 목적이 있다. 또한 수돗물 공급시설의 IoT 센서, 운영자 모니터링 시스템, 이상발생시 탐사복구 솔루션이 융합된 하나의 SWM 모델을 수립하였으며, 관련 기술 개발을 통해 국내 물산업을 육성하고, SWM을 선진수준으로 확산하였다는데 의의가 있다고 하겠다.

• 한국지역사회생활과학회지
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• 제15권3호
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• pp.3-14
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• 2004

This study examined how product characteristics and system characteristics have affected user's economic, psychological and operating satisfaction and intention of repurchase in Internet shopping malls. The results of the study were as follows: First, it showed that product characteristics and user satisfaction have significant differences; the ability to recognize economic and psychological user satisfaction differs according to the characteristics of the product. It also showed that the degree of psychological and operating user satisfaction varies according to the convenience of order and payment as well as the convenience of the system and customer service. Second, it was found that economic, psychological and operational user satisfaction had an effect on customer's intention to repurchase. This study, focusing on particular variants of on-line shopping, found that characteristics of product and system had a great impact on user satisfaction and intention to repurchase. For the firms who run internet shopping malls, therefore more attention should be directed to the convenience of products and system problems in their services since it is so easy for customers to move to another shopping site with a simple click. The result of such an investigation may lead customers to repurchase by increasing their satisfaction with the shopping services.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2009년도 하계학술발표대회 논문집
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• pp.1049-1054
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• 2009

Sustainable housing design can contribute to dramatically reduced energy usage and can be applied to all new building projects. This paper explores the potential in Korea of applying available energy efficient building technologies. The objective was to determine the degree of energy reduction that can easily be achieved in new building design. The pilot project is providing some prototypes with display units which incorporate principles of sustainable design and performance utilizing the eco-design objectives. This building challenges ingrained preconceptions about system designs for four energy saving levels(40%, 60%, 80% and zero energy) and exposes barriers to low energy buildings posed by new standards and guidelines.

• 설비공학논문집
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• 제26권7호
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• pp.322-328
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• 2014

Return piping is used in a solar combi-system for heating and hot water supply. When the temperature of the lower side of a storage tank is low due to hot water usage, the returned hot water after heating is mixed with the lower side cold water of the tank, and the useful energy is reduced. We studied the degree of thermal stratification in the tank, using either a diffuser or a manifold to prevent mixing. Using the diffuser, mixing starts from the bottom of the storage tank. On the other hand, the manifold has the marked effect of preventing mixing. As a result of experiments with changing the diameter and number of holes in the manifold, the optimum condition is 8.5 mm diameter and 96 holes, under the condition of 0.3 lpm.

• 드라이브 ㆍ 컨트롤
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• 제9권2호
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• pp.46-53
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• 2012

This paper explains how eliminating contamination from the manufacturing processes will lead to better product quality and hence the need for reworking, a trouble free commissioning period and greatly improved production efficiency. All of these will reduce costs and energy usage. It will also ensure that the product is delivered to the customer in a condition that will ensure improved reliability and longer life, again reducing both energy and other operating costs. Correctly designing the contamination control measures will achieve and maintain the level of fluid cleanliness that is required by the end user. The filter is critical to cleanliness management and should be selected with the same degree of thought and consideration as for other major components. This paper explains the role that Cleanliness Management plays in the reducing the carbon footprint of systems and processes by making them perform more efficiently for longer periods. It also examines two differing ways of selecting filters to incorporate the features of newer designs, and shows how significant savings in the costs of ownership can be achieved using these approaches.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.175-178
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• 2007

Valves has been used widely in various industries. There are many purposes for valve usage in a piping system. One of them is to control the flow rate. For a design of ball valves, it is important to know the characteristics of flows inside a ball valve. In this study, the computation fluid dynamics were conducted to observe flow velocity, flow coefficient and pressure distribution using CFX 10 according to the valve angles and uniform incoming velocity.

• 한국시뮬레이션학회:학술대회논문집
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• 한국시뮬레이션학회 2005년도 춘계학술대회 논문집
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• pp.154-159
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• 2005

In this paper, We used the microphone unlike existing urodynamic inspection which diagnoses the LUTS(lower urinary tract symptoms) and proposed sound measurement the method which the urination happens and apply at a blockade diagnosis. To analyze the blockade degree, We made the experiment set to modeling the Lower Urinry System of the human body and made the microphone of the stethoscope form for the measurement of the urinary sound which the urination happens. We used PC for the analysis of the urinary sound to be measured and implemented the analysis program to use the MATLAB. Hereafter, An analysis result usage, The Practical use will be possible as one of new inspection methods's.