• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.25 no.7
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• pp.398-405
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• 2013

Small and medium-size buildings employ a multi-distributed individual air-conditioning system that utilizes package air conditioners instead of centralized cooling systems, which can allow easier building management and maintenance, along with a diversification of facility use. Inverter driven system heat pumps have been developed to achieve not only an easy distribution control, allowing free combination of indoor units with different models and different capacities, but also wide applications to intelligent air conditioning. However, the control algorithms of the system heat pump are limited in the open literature, due to complicated operating conditions. In this paper, an inverter-driven system heat pump having two indoor units with electronic expansion valves (EEV) was simulated in the cooling mode. An integral optimum regulating controller employing the state space control method was also simulated, and applied to the system-heat pump system, to obtain efficient control of the MIMO (multi input multi output) system. The simulation model for the controller yielded satisfactory prediction results. The new control model can be successfully utilized as a basic tool in controller design.

• Journal of Environmental Impact Assessment
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• v.21 no.6
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• pp.927-939
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• 2012

Cool roofs are currently being emerged as one of important mechanism to save energy in relation to the building. Although green roof has already gained nation-wide recognition as a typical method of energy saving in the roof, this approach did not provide a realistic evidence that is economically feasible in terms of installation cost. This research is primarily intended to compare installation cost between the two techniques. This research proposes a comparative evaluation framework in a more objective and quantitative way for an installation cost between the two techniques. Kyungpook National University (KNU) was selected as a survey objective and an exhaustive and realistic comparison of installation cost between the two techniques was conducted, based on Life Cycle Cost analysis (initial investment cost, maintenance cost, dismantling and waste disposal expense). It was possible to identify that installation cost of cool roofs is 4.7 times cheaper than that of green roof. Also present value based on probabilistic approach was identified as 0.25 (4.95) higher than the installation cost on the assumption of constant price and interest. It is expected that much more installation cost for the large scale green roof will be required since small-size green roof selected as a survey objective in this study could be operated under less initial installation and maintenance condition.

• Journal of Biomedical Engineering Research
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• v.36 no.4
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• pp.86-94
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• 2015

In order for medical devices to be used outside hospital, they have to be not only of small size but also power consumption has to be kept at low level. This study investigates the feasibility of application of ADS1298 ECG single-chip solution developed by Texas Instruments Inc. for use in development of a new platform for diagnostic resting ECG. To prove the feasibility of commercial products based on the ADS1298 chip, the performance of the ADS1298 chip was measured in terms of input impedance, common mode rejection, frequency response, and input dynamic range using the testing method under the suitability criteria of the IEC 60601-2-25 standard. Result of the this study shows that commercialization of the ECG products based on the ADS1298 ECG single-chip solution that satisfies the international standards would be possible, if the manufactures take the filter characteristics into account in building a new platform for diagnostic resting ECG.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.24 no.6
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• pp.710-717
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• 2015

Projection stereolithography is an additive manufacturing method that uses beam projection to cure the photo-reactive resin used. The light source of a cross-section layer-form illuminates photo-curable resin for building a three-dimensional (3D) model. This method has high accuracy and a fast molding speed because the processing unit is a face instead of a dot. This study describes a Scalable Projection Stereolithography 3D Printing System for improving the accuracy of the stereolithography. In a conventional projection 3D printer, when printing a small sized model, many pixels are not used in the projection or curing. The proposed system solves this problem through an optical adjustment, and keeps using the original image as possible as filling the whole projection area. The experimental verification shows that the proposed system can maintain the highest level of precision regardless of the output size.

• Journal of the Korean Home Economics Association
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• v.42 no.9
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• pp.213-235
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• 2004

This study investigated the Infant Institutional Household (IIH) for the care of infants. The purpose was to provide basic information needed to raise Korea's birth rate and to design higher level nursing facilities which can satisfy working mothers who are presently offered few facilities. To achieve this purpose. IIM was divided into 7 sub-functional stations : planning-management, marketing, materials-management, business-management, man power-management, financial-management and control etc. The results are as follows : 1. Kind of facilities : Infants'(full responsibility) Institutional Household. 2. Number of infants : total 19 babies. 3. Ratio of infants to teachers : one to one (Contained assistance teachers) 4. Installing region : convenient traffic place - in Seoul. 5. Building site and kind : the first floor space of 60pyung (198㎡) in the Apartment complex which . contained many apartments of small size. 6. Nursing time : 24-hour day care in weekdays Age of object : age from 1month to 24months old babies(after his/her birth). 7. Kind of services and Cost : mother-like care, cost includes nursing-fee, a deposit and admission-fee. 8. Economic Condition and managing direction : pursuit limited profits with nursing-fee, admission-fee, a loan and national (or self -government of direct) supplementary funds.

• The Journal of Sustainable Design and Educational Environment Research
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• v.7 no.1
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• pp.29-38
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• 2008

The purpose of this study was to discuss how traditional construction practices could be applied to school buildings. The spatial arrangement and constituents of Seoweon and Hyanggyo buildings were analyzed, and the spatial arrangement and ground plans of current schools were analyzed as well. As a result, it's found that how the characteristics of traditional architecture should be reflected in today's school design is one of critical matters that need an immediate attention. Based on the case study, there are some suggestions about the application of traditional construction techniques to school buildings: (1) The link between internal and external spaces should be stressed. The type of spatial configuration the could ensure nature accessibility is required. (2) The use of environment-friendly materials is recommended, and classrooms should be arranged in a way to let them function as multipurpose educational spaces. (3) It's not advisable to construct school buildings according to the sung-Confucianistic construction techniques of traditional educational institutions, but there should evidently be a change in tasteless school buildings, They should be built in small size and in consideration of harmony with nature and ecosystem, and boarding schools should be constructed in a more careful and discreet manner.

• Journal of the military operations research society of Korea
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• v.28 no.1
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• pp.115-135
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• 2002

The limits of current DN(Defense networks), private and closed network, become to reality; for Example, high expense of construction and maintenance of networks, restriction of new subscribers on DN. Therefore, a network using web environment that reflect fast development of If and IS(Information Security) technology is demanded for MND. Meeting the requirement of reliable IS system and extension and improvement of DN using common network, we can reduce the expense to extend, maintain, repair DN, form the environment that makes military business cooperate better with civil company and government agency, advance implementing Defense computing and networking service for field small size units that was a exception of Defense digitalization. But it is essential to construct DN based on common network that there are security requisites; confidentiality, integrity, availability, efficiency, log, backup, restoration, that have to be realized at demanding level for IS. This thesis suggested four measurements; replacement DN with common network to resolve the requirements of building new network and improvement of performance for private DN, linkage with common network for new requirement, distribution of traffic using common network, configuration of DN using Internet and Proposed a refinement of IS management organization to treat security threat of common network flexibly, and LAN IS standard model of DN based on the web environment.

• Journal of the Korean Society of Safety
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• v.22 no.1 s.79
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• pp.7-12
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• 2007

There are two kinds of design process for sprinkler system. one is pipe schedule system and the other is hydraulically designed system. We have inefficient results when we design by hydraulically designed system because the design process for sprinkler system is restricted by domestic fire code. Therefore, it is essential to do an introduction of hydraulically designed system which is based on engineering for enhancing reliability and efficiency of sprinkler system. This study presents points at issue by comparing and studying design standards of sprinkler system from Korea, Japan and NFPA, and presents improvement plans of national fire safety code of sprinkler system by processing, comparing and analyzing designs according to piping schedule and hydraulically designed system about domestic objects. Installation standards of sprinkler system have to be applied not by object buildings but by hazard classification. It is hard to design an efficient sprinkler system for fire control when water supply requirement of sprinkler systems allocated according to a size of a building because the same purpose but other buildings may request more water requirement or less. We should sublate the pipe schedule system from national fire safety code and need to introduce the hydraulically designed system. The pipe schedule system presents easy access because it is based on the forecasted engineering calculations but it is applied to only small buildings like NFPA due to its low reliability.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4580-4586
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• 2013

Many school buildings are not applied seismic code because of small size structures. But it must be designed to show enough structural performance when subject to earthquake due to the fact that most of school buildings are generally used as public shelters when the natural disasters. In this study, the seismic risk of the reinforced concrete school building structure which is the most common types of school structures was evaluated by using the seismic performance evaluation methods. As a result, model structures don't have enough seismic performance.

• Journal of Drive and Control
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• v.15 no.4
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• pp.81-90
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• 2018

Indoor construction site such as building demolition sites, tunnel, vinyl house, and cattle shed are subject to various risk factors such as falling stones, soot and bad odors. However, most of the mini excavators have no cabin that can protect the driver from such risk factors. Therefore, researches on remote control technology of construction equipment are actively conducted as a method for protecting the driver from the risk factors occurring in the working environment. For effective remote control, it is necessary to be able to control the travelling and work using a portable small transmitter. However, due to the limitation of the size of the transmitter, complex operation control is required to control two or more actuators with a single joystick. Also, it is essential to check how remote control characteristics change in various environments such as distance, signal strength, obstacle. Therefore, in this study, an algorithm that can control two actuators simultaneously with a single joystick signal was developed, and a communication method suitable for indoor and outdoor mini construction equipment by analyzing experimentally how the remote control characteristics vary according to various work environments and telecommunication methods proposed.