• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.1-12
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• 2021

Technologies for an MVDC(medium voltage direct current) distribution system are being considered as an effective alternative to overcome the interconnection delay issues of PV systems. However, the implementation of a DC distribution system might lead to economic problems because of the development of DC devices. Therefore, this paper deals with the scale of a PV plant based on its capacity and proposes hosting-capacity models for PV systems to establish a network to evaluate the feasibility of an MVDC distribution system. The proposed models can be classified as AC and DC distribution systems by the power-supply method. PV systems with hundreds of MW, dozens of MW, and a few MW can be categorized as large-scale, medium-scale, and small-scale models, respectively. This paper also performed modeling for an economic evaluation of MVDC distribution system by considering both the cost of AC and DC network construction, converter replacement, operation, etc. The profit was composed of the SMP and REC rate of a PV plant. A simulation for economic evaluation was done for the MVDC distribution system using the present worth and equal-principal costs repayment method. The results confirmed that the proposed model is a useful tool to evaluate economic issues of a DC distribution system.

• Advances in Computational Design
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• v.3 no.1
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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.

• Journal of the Korean Society of Clothing and Textiles
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• v.25 no.2
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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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• v.3 no.3
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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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• v.22 no.2
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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.

• New & Renewable Energy
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• v.20 no.1
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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.

• Proceedings of the KSEEG Conference
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• 2000.04b
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• pp.145-145
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• 2000

• Journal of the Korean Society of Clothing and Textiles
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• v.38 no.2
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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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• v.55 no.5
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• pp.609-617
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• 2017

Lignocellulosic biomass is a renewable resource for production of biofuels and biochemicals. Furfural (FF) is an important platform chemical catalytically derived from the hemicellulose fraction of biomass. Tetrahydrofurfuryl alcohol (THFA) is a FF derivative and can be used as an eco-friendly solvent with thermal and chemical stability. Despite large numbers of experimental studies for catalytic conversion of FF to THFA, few research have conducted on the economic feasibility for large-scale THFA production from FF. At the stage of assessment of the potential for commercialization of conversion technology, a large-scale process study is required to identify technological bottleneck and to obtain information for solving scale-up problems. In this study, process simulation and technoeconomic evaluation for catalytic conversion of FF to THFA are performed, as the following three steps: integrated process design, heat integration, and economic evaluation. First, a large-scale process including conversion and separation processes is designed based on experimental results. When the FF processing rate is 255 tonnes per day, the FF-to-THFA yields are 63.2~67.9 mol%. After heat integration, the heating requirements are reduced by 14.4~16.4%. Finally, we analyze the cost drivers and calculate minimum selling price of THFA by economic evaluation. The minimum selling price of THFA for the developed process are $2,120~2,340 per tonne, which are close to the current THFA market price.

• Journal of Electrical Engineering and Technology
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• v.3 no.3
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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.