• Journal of Communications and Networks
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• v.12 no.5
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• pp.480-491
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• 2010

Along with the wide acceptance of IEEE 802.11 wireless local area network (WLAN), new applications such as Internet protocol (IP) telephony over WLAN are fast emerging today. For battery-powered IP phone devices, the life time extension is a key concern for the market acceptance while today's 802.11 is not optimized for snch an operation. In this paper, we propose a novel idle mode operation, which comprises paging, idle handoff, and delayed handoff. Under the idle mode operation, a mobile host(MH) without any active session does not need to perform handoff within a predefined paging area (PA). Only when it enters a new PA, an idle handoff is performed. The proposed idle mode allows an MH without traffic to extend its life time. We develop a new analytical model in order to comparatively evaluate our proposed scheme. The numerical resnlts demonstrate that the proposed scheme outperforms the existing schemes with respect to power consumption.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.11a
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• pp.149-150
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• 2011

Recently, Goverment's Energy-saving policy in Korea as 'Green Growth' is very remarkable effort. By intensive poliicies, the private is encouraged to participate in policy. Especially, it is very important in the field of architecture and we have to work for construction of law system. However, these efforts of the government buildings for energy efficiency in use stage is as mandatory system that may occur in the construction phase and the enviromental impact of greenhouse gas reductions is not affected. For this reason, Assess the amount of the energy consumption and CO₂ emissioont of Government Buildings in 2010 ordered by PPS(Public Procurement Service) in the construction phase and suggest to recognize the need for legal restrictions.

• Journal of The Korean Digital Architecture Interior Association
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• v.3 no.1
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• pp.59-62
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• 2003

The death from suffocation due to the gas from various disaster is frequent very and it occurs. Specially only from the company which treats the gas and only the enterprise which maintains the gas the many greeting accident occurs. Also accidents could occur when working around the toxic gas without one's noticing Therefore a development of the portable gas ditectoror is very essential. Specially with development of design and the new product of the electric chemical sensor might help reducing the many accidents. From the side which protects a worker's life, it isn't just simple equipment but also it must be connected directly to life saving is very important. Therefore, the key technical contents of development must be focused on sensor which is simple and easy to carry and able to detect varieties of toxic gas. So, this study is about the product design which is simple and easy to carry and to use.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.5
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• pp.558-563
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• 2014

In order to reduce the risk of deaths from hypothermia at sea, this paper suggests the performance criteria of life rafts for small fishing vessels less than 20 m in length. In our country, the life rafts are not used and have no performance criteria. This research compared the performance criteria of the domestic, foreign, international standards, and the performance comparison between foreign life rafts and the user-friendly valise prototype(2 & 4 persons) which is developed by this study. As a result, it is considered to be appropriate that ISO 9650-1 can be applied to the life rafts for offshore fishing vessels while a milder criteria can be applied to the life rafts for coastal fishing vessels.

• Food Science and Biotechnology
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• v.14 no.4
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• pp.446-449
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• 2005

Two single-magnetron heating systems (SM-HS), each with a helical glass heat exchanger and a cylindrical cavity, were combined to make a two-magnetron-in-series heating system (2MS-HS) in order to increase the heating capacity. A comparison using water showed that the heating performance of the 2MS-HS was increased by two-fold as compared to that of the SM-HS, resulting in energy saving of 7.0% in 2MS-HS. Pasteurization test of 2MS-HS conducted with model food (LB broth contaminated with Bacillus subtilis) showed two-fold higher treatment capacity compared to SM-HS. Relationships between outlet temperature of the processed food, flow rate, and residence time in the 2MS-HS were established for water. Optimum pasteurization capacity was 17 s, $73^{\circ}C$, at flow rate of 280 ml/min. The 2MS-HS could be applied to the small-scale pasteurization of liquid food.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.22 no.4
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• pp.234-240
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• 2010

In October 2009, the Ministry of Land Transport and Maritime Affairs noticed 'Environment-friendly housing construction standards and performance' to build energy saving environment-friendly housings (Green Homes) for the reduction of energy consumption and carbon dioxide emission. In this study, the $CO_2$ emissions were evaluated during the life cycle of the existing apartments which were built in 1980's and Green Home apartment. $LCCO_2$ was evaluated by dividing the life cycle into three stages which are construction, maintenance and destruction stage. $CO_2$ emission from the materials for improving insulation performance was estimated by Input-output analysis. As a result, in 40 year-life cycle of $84\;m^2$ apartment, 400.68 T-$CO_2$ was emitted from 1980's apartment, on the other hand 231.02 T-$CO_2$ was emitted from Green Home apartment.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.581-584
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• 2005

A district heating(DH) system supplies environmentally-friend heat and is appropriate for reduction of energy consumption and/or air pollutions. The objectives of this paper are to systematize data processing of transition temperature, investigate its effects on fatigue life of DH pipes and optimization for size of DH pipes. A relational database management system as well as reliable fatigue life evaluation procedures is established for Korean DH pipes. Also, since the prototypal evaluation results satisfied both cycle-based and stress-based fatigue criteria. Through the optimum design process, the cross section diminished 18.64% and the CUF diminished 23.35%. So, it can be used as useful information in the future for optimal design, operation and energy saving via setting of efficient condition and stabilization of water temperature.

• Research in Community and Public Health Nursing
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• v.30 no.4
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• pp.550-559
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• 2019

Purpose: The purpose of this study was to verify the effects of the integrated dementia managing programme for the elderly with mild dementia in which the physiological, cognitive, emotional, sociological and spiritual aspects have considered. Methods: This study employed non-equivalent control group pre-post tests with the repeated measure design. The subjects of the study were 39 elderly with mild dementia (20 in the experimental group and 19 in the control group) who have admitted to two nursing homes in B city. The data were analyzed by repeated measures ANOVA. Results: There were significant interactions between two groups and times in self-efficacy (p=.011), cognitive function (p<.001), depression (p=.005), spiritual well-being (p=.002), and quality of life (p=.037). The integrated dementia managing programme of this study showed significant positive effects on the quality of life for the elderly with mild dementia. Conclusion: On considering the current trends of aging and increasing number of the elderly with dementia, this integrated programme would be highly recommended to be used in nursing homes for the elderly with mild dementia, and contribute to improving their quality of life, and saving the social and medical expenses as well.

• KIEAE Journal
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• v.12 no.1
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• pp.105-112
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• 2012

When a building is planned and designed, the design should be able to minimize the cost during the whole life cycle of the building. This study has begun to analyze LCC about the alternative design which is applicable to renewable energy facility construction. It is reviewed domestic and foreign papers about the trend of LCC technology and it is determined the analytical method to analyze the LCC of renewable energy. Regarding the review of alternatives, it is chosen the three alternatives which are able to designed combing the renewable energy facilities and it is performed the LCC analysis about each alternative. Alternative 1 is Photovoltaic + Solar Thermal + Photovoltaic /Wind Power, Alternative 2 is Geothermal + Photovoltaic, and Alternative 3 is Photovoltaic + Solar Thermal. The LCC analysis is present value method, its analytical period is 40 years and it is applied 3.2% of real discount rate. As a result, it is proved that Alternative 1 and Alternative 3 are not able to collectible the early investment cost during the analytical period and Alternative 2 is analyzed that its pay-back period of early investment cost is about 31 years. As the final outcome of this study on case analysis, it is more advantageous to use the combination of Geothermal and Photovoltaic energy than to use the other combination in LCC aspect.

• Journal of the Korean Wood Science and Technology
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• v.38 no.5
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• pp.399-404
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• 2010

A new green home designed to save money while at the same time saving the environment with some of the finest green features available in the market. Composite column composed of structural steel and structural glued laminated timber is avery Eco-friendly building products for design building because that use recycled or second hand. For compare to compressive strength of structural glued laminated timber (glulam), structural steel, and composite column (steel-glulam), tested compressive strength of each specimen. 1) structural glued laminated timber : Theoretical compressive strength is 151.6 kN similar to elastic limits. 2) structural steel (H type) : Theoretical compressive strength is 148.2 kN little under the elastic limits. 3) structural steel (D type) : Theoretical compressive strength is 147.3 kN upper than the elastic limits. 4) composite column : Actual elastic limits are about 600 kN. Result in, composite column improve compressive strength of Structural steel column and provide structural stability of the building.