• 조명전기설비학회논문지
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• 제21권7호
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• pp.117-123
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• 2007

제조업에서 생산설비에 사용되는 중요한 에너지원 중 하나는 전력에너지이며, 에너지 다소비 업종의 생산설비 즉, 플랜트에서는 사용하는 에너지의 절감과 효율 운전은 매우 중요한 관심사항이다. 본 논문에서는 생산 플랜트의 한 공정에서 가장 빈번히 사용되는 유도전동기를 모델로 하여 실제 진단, 계측을 통하여 측정값을 얻고, 기존의 운전 중인 설비들을 고효율 기기로 교체하였을 경우의 경제성을 분석하였다. 이를 위해서 현재 운전 중인 설비와 고효율설비로 교체하였을 경우에 대하여 각각 설비들의 연간 운전비용과 자본회수계수에 의한 연간 투자비용을 계산하였고, 이를 합산한 연간 총 운용비용을 비교하여 고효율설비의 경제적 타당성을 입증하였다.

• 한국산학기술학회논문지
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• 제18권12호
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• pp.400-413
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• 2017

출소 후 건전한 사회복귀를 위해서는 법무보호대상자(이하 보호대상자)들은 반드시 진로자본을 회복해야 하는 과제를 안고 있다. 그들의 진로적응 실패는 개인은 물론 사회안전망에 불안을 가중시킬 수 있기 때문에 진로자본 회복에 대한 연구는 매우 중요하다. 본 연구를 위해 한국법무보호복지공단에서 지원을 받고 있는 보호대상자 10명에 대해 심층 인터뷰를 진행하였다. 질적 내용분석 방법으로 보호대상자들의 진로자본 손상에 따른 어려움과 그 어려움을 극복하기 위한 노력, 극복하는데 도움이 된 요인, 직업생활에 적응하기 위한 요건 등 진로 주제를 심도 있게 분석하였다. 분석 결과 보호대상자들은 수감생활로 진로자본 손상을 경험하며, 사회적 자기에 대한 부정적인 개념, 사회적 낙인의 두려움, 자기에 대한 평가절하가 진로자본 회복과정에서 자신감 결여와 소극적인 태도로 나타났다. 또한 부정적 평가에 대한 두려움 등이 사회적 관계를 더욱 어렵게 하는 요인이었다. 한편, 진로자본 회복과정에서 사회적 지지는 긍정적인 영향을 미친 것으로 나타났다. 특히 배우자, 고용주, 가족, 친구들의 정서적 지지가 가장 큰 도움이 된 것으로 분석되었다. 직업적응을 위한 노력으로 진로에 대한 적극적이고 주도적인 태도와 긍정적인 자세가 중요하며 가족관계, 사회적 관계에서의 긍정적인 평가와 인정, 진로 성공경험 등이 일에 대한 자신감 상승으로 나타났다. 종합하면 진로자본 회복과정에서 역기능적 신념은 부정적인 영향을 미치고, 사회적 지지는 긍정적으로 영향을 미치는 것으로 분석되었다.

• 대한전기학회논문지:전력기술부문A
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• 제49권5호
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• pp.199-204
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• 2000

This paper presents new approaches for the calculation for the calculation of each user's wheeling prices based on the economic analysis method with focus on the postage stamp rule. The suggested postage stamp rules can overcome the following problems embedded in the conventional accounting-costs-based methods such as the volatileness of wheeling prices depending deprieciation methods, emerging the wheeling free-riders due to the difference between accounting life-time and technical life-time, price discrimination between firm and non-firm network users, etc. To solve these problems we suggest new postage stamp rules employing capital recovery factor for investment costs treatment and applying technical life-time. Furthermore, we have suggested a new formulation for non-firm wheeling users based on the wheeling energies. In the case study, the results of suggested postage stamp methodologies are compared with those of conventional approaches.

• 플랜트 저널
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• 제17권2호
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• pp.48-53
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• 2021

900 MW 복합화력발전소의 경우 소내 부하의 대부분은 회전기기이며 저역률로 운전되고 있고 역률 저하는 무효전력을 증가시켜 기기의 효율 저하 및 불필요한 소내 전력을 소비하는 원인이 된다. 본 연구에서는 이러한 문제점을 해결할 수 있는 방안인 무효전력을 흡수 및 제거하는 무효전력보상장치를 6.9 kV 소내 모선에 설치하여 운전함으로써 그에 대한 결과를 제시하고자 한다. 본 시스템의 적용 결과 우선 회전기기의 역률이 0.22로 개선 및 소내 부하전력량 1.4% 감소됨을 확인하였고 발전기 열효율 0.1%, 발전출력810 kW 증가함을 알 수 있었다. 다음으로 투자비 1.5억 원 대비 소내 전력손실비용 2억 원/년 감소 및 매출액 10억 원/년 증가로 경제성 있음으로 분석되었고 향후 건설 및 운영 시 비용절감이 가능함을 확인하였다.

• International Journal of Computer Science & Network Security
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• 제22권3호
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• pp.67-76
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• 2022

COVID-19 struck labor markets around the world, exposing and exacerbating the gender inequalities within the human capital structure. The last, in its turn, jeopardizes the return of the national economies to the growth trajectory undermined by pandemic impact. The authors assume that COVID-19 disproportionately affected the employment rates of women and men, which led to increased gender inequality in the labor market, which, in turn, affected GDP growth rates in the EU. To prove this hypothesis two research questions are discovered: 1) whether there was a different correlation between the number of COVID-19 cases in the EU and indicators of the labor market for women and men; and 2) whether there was a link between the growth of gender inequality in the EU labor market and the GDP dynamics in these countries. The analysis of the correlation between the number of cases of COVID-19 and indicators of the labor market in the EU revealed faster growth of women's unemployment rates compared to men's ones as the COVID-19 incidence unfolded. Multiple linear regression and factor analysis have been used to investigate the influence of gender inequality in the labor market on GDP dynamics. Despite the methodological limitations, the proposed model is both a sound argument and an analytical basis in favor of gender-responsive economic recovery backed by the systematic and consistent gender equality policy of a government.

• 전기학회논문지
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• 제59권6호
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• pp.1046-1052
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• 2010

In residential house, photovoltaic (PV) system among various alternatives in renewable energy system is the most efficient and feasible solution for reducing energy consumption and electricity cost. However, relatively high initial cost make people reluctant to install PV system in their houses. Therefore, in the initial state for PV system installation in the house, it is very important to decide proper capacity of the PV system considering the expected energy usage and solar energy supplying condition with the house. This paper proposes a novel optimization model for deciding appropriate capacity of the PV system for residential house. The objective function of the model is to minimize the annual cost including electricity bill, operation and maintenance cost, and annual fixed cost calculated from the initial installation cost based on capital recovery factor (CRF). The model also shows the optimal inclining angle of PV panels of the system. In this paper, we estimate the PV output using PVWATTS (PV simulator of Office of Energy Efficiency and Renewable Energy) and find optimal solutions by Sequential Quadratic Programming (SQP) method using MATLAB software. The proposed approach is finally applied to a residential model house in Gangneung, Gangwon-Do and verified its feasibility for adopting to PV system design for residential houses.

• 한국태양에너지학회 논문집
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• 제31권6호
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• pp.23-31
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• 2011

The wind energy is one of the most prospective resources in renewable energy. However, the WTGS shouldn't be installed indiscriminately because the power system can be negatively influenced by a variable and uncertain nature of the wind energy. It is the reason why it has to be limited to install the WTGS thoughtlessly mentioned above that support the importance of the maximum penetration limit of wind power. It may required that power system operators suggests a new way of power system operation as percentage of the WTGS increase in the existing power system. The wind power is fixed in a limited area, so using rate of the wind power will be increased by installing additional WTGS. In this paper, we have studied on economic evaluation of the wind capacity increased by restricting the output of the WTGS as the way to increase the wind capacity.

• 한국식생활문화학회지
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• 제35권2호
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• pp.156-166
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• 2020

In this study, 594 questionnaires administered to men and women residing in the capital metropolitan area who work night shifts were analyzed in order to study the effect of health information cognition on healing needs in accordance with the type of food selection criteria of the night worker. The results of confirmatory factor analysis in deriving food selection type identified four categories, a safety seeking type, a food exploratory type, a habitual seeking type, and a rational type, and the cognition types on health information were classified into physical cognition and psychological cognition. The need for healing, which was the investigated factor, was found to have a high correlation between questionnaire items with high reliable consistency. The results of this study were as follows. First, the food selection types of safety seeking type and habitual food seeking type had significant positive effects on the cognitive level of physical health information, and food exploratory type and habitual seeking type had significant positive effects on the cognitive level of psychological health information. In addition, it was shown that food exploratory type and rational type had significant positive effects on healing needs. As a result of this study, it was found that the cognition level of physical and psychological information was different according to food selection type, and the higher the cognitive level, the higher the healing needs. In particular, the result that the level of psychological health information significantly affected healing needs signifies that there is a demand to develop programs and menus that satisfy various needs related to healing and recovery from fatigue. In addition, further interest and study on the health and healing of night workers are required.

• 대한토목학회논문집
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• 제32권4D호
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• pp.357-366
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• 2012

기존의 품셈과 지방세법은 건설중장비가 수 년에 걸친 감가상각 대상임에도 불구하고, 물가지수를 제대로 반영하지 못하고 있다. 이에 본 연구에서는, 법인세법과 지방세법 및 기업회계기준서를 분석하여 국내 감가상각제도의 특징과 상각방법을 정리하여 제시하였고, 경제성 이론이 반영된 건설중장비 자본회수계수를 제시하였고, 정액법과 정률법을 사용하여 표준품셈을 기준으로 한 감가상각과 세법을 기준으로 한 감가상각 사례를 제시하였다. 개선방안으로는, 건설중장비의 자발적 사용기간 신청제도와 현행제도와의 관계를 설명하고 도입을 제안하였으며, 국내물가지수를 기초로 월단위 기계경비 감가상각율표를 개발하여 제공하였으며, 그 적용방안을 예시하였다. 또한, 제안한 방안의 장점과 단점을 분석하여 연구의 적용한계와 차후 개선방향도 제시해 보았다. 본 연구를 통해 품셈과 세법에 보다 합리적이고 객관적인 현실성을 반영할 수 있을 것으로 판단된다.

• 한국수소및신에너지학회논문집
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• 제30권1호
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• pp.21-28
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• 2019

Reversible solid oxide fuel cell (ReSOC) system was integrated with waste steam for electrical energy storage in distributed energy storage application. Waste steam was utilized as external heat in SOEC mode for higher hydrogen production efficiency. Three system configurations were analyzed to evaluate techno-economic performance. The first system is a simple configuration to minimize the cost of balance of plant. The second system is the more complicated configuration with heat recovery steam generator (HRSG). The third system is featured with HRSG and fuel recirculation by blower. Lumped models were used for system performance analyses. The ReSOC stack was characterized by applying area specific resistance value at fixed operating pressure and temperature. In economical assessment, the levelized costs of energy storage (LCOS) were calculated for three system configurations based on capital investment. The system lifetime was assumed 20 years with ReSOC stack replaced every 5 years, inflation rate of 2%, and capacity factor of 80%. The results showed that the exergy round-trip efficiency of system 1, 2, 3 were 47.9%, 48.8%, and 52.8% respectively. The high round-trip efficiency of third system compared to others is attributed to the remarkable reduction in steam requirement and hydrogen compression power owning to fuel recirculation. The result from economic calculation showed that the LCOS values of system 1, 2, 3 were 3.46 ¢/kWh, 3.43 ¢/kWh, and 3.14 ¢/kWh, respectively. Even though the systems 2 and 3 have expensive HRSG, they showed higher round-trip efficiencies and significant reduction in boiler and hydrogen compressor cost.