• 한국산학기술학회논문지
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• 제22권3호
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• pp.1-12
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• 2021

MVDC 배전기술은 현재 급격하게 도입되고 있는 태양광전원의 접속지연 문제를 해결하기 위한 효과적인 대안으로 평가되고 있지만, DC 배전망용 기기들을 개발해야 하므로 DC 배전망의 구축비용은 경제적인 측면에서의 문제점을 가지고 있다. 따라서, 본 논문에서는 태양광전원의 수용을 위한 MVDC 배전망의 도입 타당성을 평가하기 위하여, 태양광전원 단지를 용량에 따라 규모별로 정의하고, 이를 수용하기 위한 배전망을 건설하는 경우에 대하여 규모별로 수용성 모델을 제시한다. 이 모델은 배전망의 전원공급방식에 따라 AC 및 DC 배전망으로 구분되며, 수용할 태양광전원 단지의 용량에 따라 수백 MW급은 대규모, 수십 MW급은 중규모, 수 MW급은 소규모로 정의된다. 또한, 본 논문에서는 AC 및 DC 배전망의 건설비, 전력변환설비의 교체비, 운용비로 구성된 비용요소와 태양광전원의 발전수익에 따른 전력량 요금 및 REC 요금으로 구성된 편익요소를 고려하여 MVDC 배전망의 경제성평가 모델링을 제시한다. 이를 바탕으로 현재가치 환산법과 원금균등상환 방식을 이용하여 MVDC 배전망의 경제성을 평가한 결과, 태양광전원의 수용 규모에 따라 일정 연계거리 이후에서는 DC 배전망의 구축비용이 기존의 AC 배전망보다 경제적임을 알 수 있어, 본 논문에서 제시한 경제성평가 모델링의 유용성을 확인하였다.

• Advances in Computational Design
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• 제3권1호
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• pp.17-34
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• 2018

Tall buildings are categorized as important structures because of the large number of occupants and high construction costs. The choice of competent lateral load resisting systems in tall buildings is of crucial importance. Bracing systems have long been an economic and effective method for resisting lateral loads in steel structures. However, there are some potential adverse aspects to bracing systems such as the limitations they inflict on architectural plans, uplift forces and poor performances in compression. in order to eliminate the mentioned problems and for cost optimization, in this paper, six 20-story steel buildings and frames with different types of bracing, i.e., conventional, mega-scale and buckling-restrained bracing (BRB) were analyzed. Linear and modal push-over analyses were carried out. The results pointed out that Mega-Scale Bracing (MSB) system has significant superiority over the conventional bracing type. The MSB system is 25% more economic. Some other advantages of MSB include: up to 63% less drift ratio, up to 38% better performance in lateral displacement, up to 100% stiffer stories, and about 50% smaller uplift forces. Moreover, MSB equipped with BRB attests even a better seismic behavior in the aforementioned parameters.

• 한국의류학회지
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• 제25권2호
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• pp.228-236
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• 2001

Economic crisis in Korea since December 1997 had tremendously affected consumer behavior. This study examined consumer perception of the economic crisis and investigated its impacts on consumer ethnocentrism and purchase behaviors of foreign products. Two product categories of clothing and cosmetics were selected fro empirical testing. Data were obtained from a questionnaire survey to female consumers in Korea during September 1998, and 468 responses were analyzed. The consumer perception of the economic crisis(PCEP) scale was developed for the study. Correlation and regression analyses revealed: 1) the positive relationship between PCEP and consumer ethnocentrism(ETHN); 2) the positive effects of attitude toward foreign products(ATTI) on actual purchase of foreign products since the economic crisis(PB) and on purchase intention of foreign products(PI) for both clothing and cosmetics; 3) the negative effect of ETHN on PI for both product categories; and 4) the negative effects of PCEP on PB and PI for clothing.

• International Journal of Contents
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• 제3권3호
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• pp.20-25
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• 2007

Standards impact the economy in various ways. Moreover, intense competition exists between a variety of standards in this era of globalization. This paper quantifies the economic effect of multiple standards in the Information Communications and Technology (ICT) sector. Thus, it identifies and specifies which standard applies when economic gains exist. A model is developed which quantifies the magnitude of the economic effect of multiple standards as compared with a single standard or no standard. The model allows for both the micro- and macroeconomic gains from standardization to be quantified. Preliminary estimates indicate that at the macro level the multiple standards multiplier is approximately three. That is for every dollar invested, the gain is on the order of three dollars. Although not as robust. preliminary results indicated a similar economic gain at the micro level Overall, multiple standards dominate a single standard. This paper applies the model to IMT-2000, an example of multiple standards, to demonstrate this approach to quantify the standards economic effect.

• International Journal of Computer Science & Network Security
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• 제22권2호
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• pp.9-14
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• 2022

The main purpose of the study is to determine the main features of the socio-economic development of the countries of the world under the influence of the digital economy and COVID-19. The modern world has already taken the first step towards a fundamentally new technological, economic and social reality. However, the challenges facing the modern industrial society cannot be overestimated. We are talking about changing the global socio-technological order, the consequence of which is a complete reformatting of the systems familiar to us, the formation of new social and economic strategies. the technological paradigm is immediately changing, management models and social norms are changing, large-scale demographic shifts are taking place. As a result of the study, key aspects of socio-economic development in the digital economy were identified.

• 신재생에너지
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• 제20권1호
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• pp.15-25
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• 2024

This study analyzes the economic feasibility of agrivoltaics in South Korea. The key findings are as follows. It was ascertained that an amendment to the Farmland Act, which currently has an 8-year permit period, is necessary to ensure the economic feasibility of agrivoltaic projects. Furthermore, economic feasibility improves when agrivoltaic projects are financed, as against cases without financing. Furthermore, the availability of low-interest loans through financial support programs significantly enhances economic feasibility. Scaling up projects leads to cost savings due to economies of scale, while community-based agrivoltaic initiatives generate higher revenue through the acquisition of additional Renewable Energy Certificates. These factors can help improve the economic feasibility of agrivoltaic projects. These incentives are emphasized as they can serve as a source of funding to foster community acceptance of agrivoltaic projects.

• 대한자원환경지질학회:학술대회논문집
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• 대한자원환경지질학회 2000년도 춘계공동학술발표회
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• pp.145-145
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• 2000

• 한국의류학회지
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• 제38권2호
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• pp.137-146
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• 2014

The practice of sustainability is an important subject to integrate into the management, product planning, manufacturing by textile and fashion companies as well as consumption by end-users. This study shows an evaluation scale designed to assess the practical cases in order to suggest efficient and systematic methods to fulfill the practice of sustainability in textile and fashion companies. First, companies should practice environmental sustainability to use eco-friendly material and cleaner production, protect the environment, and save natural resources. Second, social sustainability is required to fulfill social responsibility and ethical needs. Third, companies should perform various innovative activities, transparency in management, fair competition and economic contribution in the local community in order to maintain economic sustainability to survive in industry. Finally, cultural sustainability should be fulfilled by textile and fashion companies as part of the intellectual-cultural industry in a way that increases the importance of ethnic and cultural diversity. Textile and fashion companies should fulfill four environmental, social, and economic cultural sustainable subjects in a balanced method to accomplish sustainability. The concerns and practices of environmental sustainability are comparatively highly rated due to the analysis of the evaluation scale. However, cultural sustainability (a need of the times) is poorly rated and needs more attention. Therefore, the evaluation scale can be used as a standard tool to fulfill the sustainability of companies and brands from the viewpoint of improving poor and insufficiently sustainable items as well as balancing sustainability management.

• Korean Chemical Engineering Research
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• 제55권5호
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• pp.609-617
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• 2017

목질계 바이오매스는 바이오 연료 및 바이오 화학제품 생산을 위한 재생 가능 자원이다. 푸르푸랄(furfural, FF)은 목질계 바이오매스의 헤미셀룰로스로부터 화학적 촉매전환으로 유도되는 주요한 플랫폼 케미칼이다. 테트라히드로푸르푸릴 알코올(Tetrahydrofurfuryl alcohol, THFA)은 FF의 유도체로 열적 화학적 안정성을 지닌 친환경 용매로 이용 가능하다. FF를 THFA로 전환하는 실험적 연구가 다수 존재함에도 불구하고, FF로부터 THFA의 대량생산에 관한 경제적 실현가능성에 관한 연구는 거의 수행되지 않았다. 개발된 전환기술의 상용화 단계에서 기술적 병목점 확인과 스케일업 문제의 해결을 위한 정보를 얻기 위해 실증플랜트 규모의 연구가 필요하다. 본 연구에서는 FF의 THFA로의 화학적 촉매전환에 대해 공정 시뮬레이션 및 기술경제성 평가가 수행되며, 3가지 단계(통합 공정 디자인, 열 통합, 경제성 평가)를 거친다. 실험연구 결과를 기반으로 전환공정과 분리공정을 포함하는 실증플랜트 규모의 통합공정이 설계된다. FF 처리량은 일일 255톤이며, FF로부터 THFA로의 수율은 63.2~67.9 mol%이다. 통합공정에 대해 열 통합을 수행하여 가열요구량을 최초 대비 14.4~16.4% 감소시킬 수 있었다. 최종적으로 경제성 평가를 통해 전체 공정의 주요 비용원을 분석하고 THFA의 최소판매가격을 결정하였다. 개발된 공정에서 생산되는 THFA의 최소판매가격은 1톤당 2,120~2,340 달러로, 현재 THFA의 시장 가격에 근접한다.

• Journal of Electrical Engineering and Technology
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• 제3권3호
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• pp.320-330
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• 2008

This paper presents an improved dynamic programming (IDP) approach to solve the economic power dispatch problem including transmission losses in power systems. A detailed mathematical derivation of recursive dynamic programming approach for the economic power dispatch problem with transmission losses is presented. The transmission losses are augmented with the objective function using price factor. The generalized expression for optimal scheduling of thermal generating units derived in this article can be implemented for the solution of the economic power dispatch problem of a large-scale system. Six-unit, fifteen-unit, and forty-unit sample systems with non-linear characteristics of the generator, such as ramp-rate limits and prohibited operating zones are considered to illustrate the effectiveness of the proposed method. The proposed method results have been compared with the results of genetic algorithm and particle swarm optimization methods reported in the literature. Test results show that the proposed IDP approach can obtain a higher quality solution with better performance.