• Journal of the Architectural Institute of Korea Structure & Construction
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• v.35 no.11
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• pp.181-188
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• 2019

The purpose of this study is to evaluate the cooling energy saving effects of CRAH supply air temperature(SAT) and design flow rate changes when applying air-side economizer in the data center. MLC(Mechanical Load Component), which is cooling performance indicator of data center, was used to assess the effectiveness of cooling energy savings. It was computed with energy simulation (DesignBuilder) to evaluate the cooling energy performance of 8 different alternatives in a data center. The MLC was 0.31~0.32 regardless of CRAH supply temperature without air-side economizer, and 0.15 to 0.19 value with air-side economizer. That is, cooling energy can be reduced by approximately 40~55% when applying economizer. As the CRAH SAT and design flow rate changed, the MLC values were 0.16 to 0.18 and 0.15 to 0.19, respectively.

• Journal of the Korean Operations Research and Management Science Society
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• v.36 no.3
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• pp.61-74
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• 2011

The objective of this study is to evaluate the effects of sharing uncertain yield information with a downstream supply chain player. We are interested in understanding how the amount of yield uncertainty affects the supply-side benefits and/or costs, which has not been considered in the literature, in addition to the customer-side benefits. With that purpose, this work evaluates a supplier who provides yield information in comparison with another supplier who shares no information. We simulate an order-up-to type heuristic policy that is adapted from the literature and reasonably modified to represent yield information sharing with error. From the simulation study, we argue that the customer would experience cost reduction, but the cost for supplier's inventory is increasing when sharing yield information. Furthermore, the amount of benefits and costs are situational and affected by level of yield uncertainty and demand variance. Based on the simulation study, we finally make several recommendations for the supply-side approaches to yield information sharing.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.149-151
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• 2005

Recently, power supply-demand instability due to the dramatic increase in power usage suchas air-conditioning load at summertime has brought forecasts of decrease in power supply capability. Therefore improving the load factor through systematic load management, in other words, Direct Load Control became necessary. Direct Load Control(DLC) system is kind of a load management program for stabilization of electric power supply-demand. It's purpose is limiting the demand of the demand side selected at peak load or other time periods. The paper presented a Design of Direct Load Controller for control the amount of power demand in demand side. The proposed Controller is cheaper and has ability of storing more power data than pre-existing device.

• THE INTERNATIONAL COMMERCE & LAW REVIEW
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• v.38
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• pp.229-262
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• 2008

With the introduction of supply chain management concept, the nature of a firm is fundamentally changed. Control is no longer based on direct control of the business processes, but rather based on integration across member organizations in the supply chain. Firms are trying to achieve a competitive edge by managing their supply chain performance to gain advantages in cost and service differentiation. The supply chain elements of a sea port involves ILSP (Inbound Logistics Service Provider) at the input side and OLSP (Outbound Logistics Service Provider) at the output side. The goal of sea port is to satisfy the needs of different parties, both upstream and downstream, in the chain with greater effectiveness and efficiency than it's competitors. In this context, the purpose of this paper is to derive conceptualization of the SCP (Supply Chain Performance) in the sea port from literature review on the previous researches and to tackle their theoretical and practical implications. The paper deals with conceptualizing SCP in sea port using the SCOR (Supply Chain Operation Reference) model. It incorporates both the effectiveness and efficiency aspects of performance measurement. And it also recognizes customer related reasons for measuring performance.

• Journal of the Korean Home Economics Association
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• v.29 no.1
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• pp.51-58
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• 1991

This study was conducted to investigate the dietary and nutritional status supplied by group feeding for blue color and white color in Seoul and Kyunggi area. The results are summarized as follows : 1. Blue color and white color of the average food supply per person per day was 1370.0g. Blue color of the total fool supply was consisted of 35.1% grain, 44.1% vegetables. White color of the total fool supply was consisted of 31.8% grain, 44.0% vegetable. The amount of milk product, fruit and fat supply were very small. 2. Blue color and white color of the ratio of main dish and side dish supplied was 69 : 31, 60.0 : 39.7. 3. Main dish all is rice. Side dish ard kinds of soupes and Jigeai Johngol in the two groups. In the kind of side dish white color much more than blue color. Dessert are scarcely supplied in the two groups. 4. The mean daily supplies of energy and 9 nutrients were above the level of the R.D.A. Blue color and white color of the mean daily amount of energy supply was 2653.0㎉ 3022.6㎉. Blue color and white color of the ratio of carbohydrate, protein, and fat supplied was 68.4%, 18.6%, 13.1%, and 62.1%, 20.9%, 17.0%. 5. Blue color and white color of the average feeding cost amounts to 460won, 812won per meal. 6. Blue color; There were high correlations in supply amoung energy, protein, fat. Carbohydrate, calcium, iron, riboflavin, niacin. White color; There were high correlation in supply amoung energy, protein, carbohydrate, calcium, iron, thiamin, riboflavin, niacin, vit-C.

• Environmental Engineering Research
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• v.16 no.1
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• pp.19-27
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• 2011

This paper introduces an approach to identify the total energy consumption with subsequent $CO_2$ emissions, for both industrial and non-industrial sectors. Statistical data for 2005 were compiled in a national account system to construct an energy input-output table for investigating the influence between energy demand and supply activities. The methodological approach was applied to South Korea. Twelve types of energy and fifteen industrial and non-industrial sectors are formed as the compartments of the input-output table. The results provided quantitative details of the energy consumption and identified the significant contributions from each sector. An impact analysis on the $CO_2$ emissions for the demand side was also conducted for comparison with the supply side.

• Proceedings of the KSR Conference
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• 2006.11a
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• pp.209-218
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• 2006

This paper presents the comparison and analysis of the power supply system of a Maglev train and conventional electric railway. Even though all Maglev trains have batteries on their vehicles, electric power supply from the ground side is necessary for levitation, propulsion, on-board electrical equipment, battery recharging, and so on. At low speeds up to $100{\sim}150(km/h)$, the Maglev train, generally, uses a mechanical contact, a current collector as same as conventional electric railway. However, at high speeds, the Maglev train can no longer obtain power from the ground side by using a mechanical contact. Therefore, high speed Maglev trains use their own way to deliver the power to the vehicle from the ground. In this paper, the power supply systems of the german, japanese, and korean low- and high-speed Maglev trains have been reviewed.

• Journal of information and communication convergence engineering
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• v.3 no.4
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• pp.184-186
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• 2005

The effect of power supply noise on the phase noise of a ring oscillator is studied. The power supply noise source in series with DC power supply voltage is applied to a 3 stage CMOS ring oscillator. The phase noise due to the power supply noise is modeled by the narrow band phase modulation. The model is verified by the fact that the spectrum of output of ring oscillator has two side bands at the frequencies offset from the frequency of the ring oscillator by the frequency of the power supply noise source. Simulations at several different frequency of the power supply noise reveals that the ring oscillator acts as a low pass filter to the power supply noise. This study, as a result, shows that the phase noise generated by the power supply noise is inversely proportional to the frequency offset from the carrier frequency.

• Journal of The Korean Digital Architecture Interior Association
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• v.9 no.2
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• pp.57-65
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• 2009

Housing Re-Development business is to improve the environment of old residential area and secure insufficient infrastructure facilities for the public, and to provide housing of fine quality for the individuals and it is taken as an opportunity for the individuals to be able to increase their property. However, it is true that the benefits from the redevelopment has not offered to the original dwellers who has lived there for a long time. This research studies the related systems of the Rental House Redevelopment Supply Service and is to present the schema to raise resettlement rate through the investment on the rate of tenants who chose the rental house and their specific characters. This study is to present the reform measures about the following 3 problems, on the basis of prior theoretical studies which deals with the common factors having low rate to move in the rental house of the tenants. (1) Physical side, the problem of supply structure, which is not appropriate Housing Supply Structure, (2) Psychological side, the problem of socially excluded rental house residents (3) Economical side, low re-settlement rate of tenants caused from the unreasonableness of the estimated rental value. This study presents that the compulsory rental housing supply rate should be changed to the gross area not from the number of households, and the supply of rental houses should correspond to the household size of tenants through prior demand survey. Secondly, it proposes the housing complex layout for intermixing to solve the social problems to allow a housing for sale and rental houses mixing in a building. And it proposes that the rental value should be calculated considering the neighboring value and in the long run, it should be calculated considering the tenants' income instead construction cost estimate. Also, it should be arranged to provide an opportunity to create income through resident welfare center improvement and provide self-sufficiency functions leading residents to participate in the residential area's repairing and maintenances.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.4
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• pp.179-186
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• 2015

In this study, the actual energy consumption of the secondary side District Heating System (DHS) with different hot water supply temperature control methods is compared. The two methods are Outdoor Temperature Reset Control and Outdoor Temperature Predictive Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side system, the results show that the Outdoor Temperature Predictive Control method saves more energy. In general, the Outdoor Temperature Predictive Control method lowers the supply temperature of hot water, and it reduces standby losses and increases the overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, the Outdoor Temperature predictive Control method saves about 6.6% of energy when compared to the Outdoor Temperature Reset Control method. Also, it is found that at partial load condition, such as during daytime, the fluctuation of hot water supply temperature with Outdoor Temperature Reset Control is more severe than that with Outdoor Temperature Predictive Control. Thus, it proves that Outdoor Temperature Predictive Control is more stable even at partial load conditions.