• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.26-28
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• 2007

To estimate reasonable load factor of power system both supply side and demand side of views should be considered. In the case of this study the demand side is considered and it is supposed that load curves depends on the load factor. The key point of this study is that the cost of demand-side management program per kW and/or kWh should be calculated.

• The Transactions of the Korean Institute of Power Electronics
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• v.4 no.1
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• pp.105-110
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• 1999

This paper describes the inverter driven air-condetioner with power factor correction (PFC) circuit. By adopting PFC in the rectifier, we can reduce harmonic injection into power line, improve the efficiency and lower the total system cost compared to conventional inverter only. Also, system performance is improved by stabilizing the output voltage of PFC. In this paper, detailed design procedures for PFC are given, and the several merits with PFC are verified through the simulation and experiment.

• International Commerce and Information Review
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• v.6 no.3
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• pp.123-136
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• 2004

In recent years, although far behind, the "e-Trade (B to G)" is propelled vigorously in Japan. But the diffusion of the "e-Trade" among companies (B to B) represented by bolero.net does not meet expectation. This paper carried out the questionnaire survey to the enterprises, which adopt bolero.net and examined why the diffusion is stagnated to the measures for its future spread. As a result, the top 3 adoption factors are: (1) Transaction climate, (2) Top management support, and (3) Operational improvement. In other words, it depends that top management has the will, which adopts e-trade positively among the reliable business partners and the operational performances can improve efficiently by carrying e-trade. We would like to clarify what will be crucial to spur the diffusion in the future. Based on the findings from the result, the concrete key points to promote the spread are to be indicated as follows: (1) Improve the scores of "Cost" and "Competitive pressure" (2) Improve the institutional factor.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.241-242
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• 2015

According to globalization of world economy on distribution and sales, logistics and transportation parts are play important role. Especially, it important to know and study how to choose right transport route and which is the key factor of route choice model in multimodal transport system. Thus this study aims to consider 4 main factors: cost, delivery time, freight, and logistics service factors additionally dividing into 13 sub factors and object is forwarders between Mongolia and Korean freight transport. The survey is based on AHP through interview with company officials. The paper provides empirical insights about current status of Mongolian forwarders and difference of the important factors between transportation modes. Result shows that time factor is role factor to choose transport route and then cost factors. Additionally, this study shows 2 different route choose factors between air transport and shipping transport forwarders.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.2
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• pp.144-149
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• 2016

This paper presents a power control method of high-speed single-phase BLDC motor. Most electric appliances require a power factor corrector (PFC) to mitigate grid current harmonics. However, the reactive components and power semiconductors in the PFC increase system cost and dimension. In this paper, a new motor drive system for a high-speed single-phase BLDC motor is proposed, which can decrease grid current harmonics without PFC by directly manipulating motor power and eliminating bulky electrolytic dc-link capacitor. Given that the proposed motor power control method does not require motor current controller, no current sensor is necessary. Moreover, the proposed algorithms can be easily implemented using a low-cost micro-controller. The effectiveness of the proposed power control method is verified by experiments.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.669-672
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• 2001

Generally, previous converter is divided into two categories to get high power factor and good output regulation. These two categories can be combined a category with a main switch. These converter is called Single Stage PFC Converter. This approach has good electrical characteristics of high power factor and fast output voltage regulation. The cost and size are important factor to design the converter in low power system. Even single stage can reduce the size and cost, but this approach needs to have additional circuit like control, PWM circuit. To improve these demerits, Top switch is one of good choice In reduce and size in low power single stage converter. Because it has the ability of current limit, thermal protection, oscillator, control circuit as well as a main switch ability.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.284-286
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• 2004

When Power market is restructured, we have an argument with selecting Transmission loss factors. First, we determine the method of calculating Transmission loss factor using OPF (Optimal Power Flow) or PF (Power Flow Equation). Then, we decide that we applicate the factor which are identical value all the year or which are floating Transmission loss factor every each hour. In this study, we accomplish the method of computing Transmission cost in competitive market.

• Korean Journal of Construction Engineering and Management
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• v.12 no.5
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• pp.127-136
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• 2011

The purpose of this study is analyzed the importance ratio factors of sales price for apartment building construction projects. For this Study, Nine apartment buildings that sold in Seoul, Gyenggi, Chuncheong is selected. The study suggested eight influence factors through interview with experts, research related references, and analysis of cases. Based on those factors, Importance analysis is performed by using AHP method. The result of this study are as follows: 1) Influence factors of sales price are drawn as cost, site, housing, transportation, region, ground, policy, investment factor. 2) In the case of Seoul, The priority order of price influence factors consist of investment factor(16.0%), policy factor(14.6%), and cost factor(13.9%). In the case of Gyenggi, The priority order of sales price influence factors consist of region factor(15.9%), transportation factor(13.8%), and investment factor(13.4%). In the case of Chungcheong, The priority order of sales price influence factors consist of region factor(17.1%), transportation factor(16.4%), and housing factor(14.9%).

• Journal of Korean Society for Quality Management
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• v.49 no.2
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• pp.213-231
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• 2021

Purpose: This study intends to provide decision-making information to improve efficiency by analyzing the management efficiency of smart greenhouse business entities and identifying factors that affect the efficiency based on input and output. Methods: The subjects of analysis were business entities for cultivating strawberries in smart greenhouses in Jeolla region (northern and southern Jeolla provinces), and the analysis focused on the management performance of the 2019-2020 crop period (year). Data Envelopment Analysis(DEA) was applied as an analysis method for efficiency analysis, Quantile Regression(QR) analysis was applied as a factor affecting the efficiency. Results: The reason for the efficiency gap between business entities was that there were many business entities that did not minimize the input cost at the current level of output, and the area where the variance among business entities was large was the fixed cost per 10a. In the results of the affecting factor analysis, it was found that the seed-seedlings cost, fertilizer cost, other material cost, and employment and labor cost had a negative (-) effect on the efficiency, and that the repair and maintenance cost had a positive (+) effect. Conclusion: Therefore, to achieve the efficiency of scale, it is necessary to reduce the input scale to an appropriate level. In the case of business entities with low efficiency by quartile, the seed-seedlings, fertilizer, and other material costs reduce expenditures, and repair maintenance costs can improve efficiency by increasing expenditures.

• Ecology and Resilient Infrastructure
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• v.9 no.3
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• pp.174-182
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• 2022

The existing cost calculation standard for the implementation project to manage total maximum daily loads calculates cost by considering the area scale and the population based on the basic cost. This method renders it difficult to calculate cost when the detailed characteristics of a business are considered. Therefore, in this study, we proposed a costing method that applied the standard fee calculation, reflecting the area scale, a number of human and livestock, wastewater discharge facilities, etc. And, through the review of related order cases, the suitability of factors affecting the implementation project is verified and the appropriateness of the cost calculation method is verified.