• Prospectives of Industrial Chemistry
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• v.20 no.5
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• pp.37-45
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• 2017

현재 국내 건설기계 부품의 대부분이 수명 시간이 도래한 중고 장비가 동남아시아 등지로 재제조 되지 않고 수출되거나 폐기되고 있다. 이를 재제조함으로써 자원순환이란 관점에서의 많은 경제적 환경적 이점들을 충족하고자 하며, 선진국들과 중국도 일찍이 건설기계 부품 재제조 사업을 장려하고 있다. 재제조 사업은 부가가치가 높아 여러 국가의 유명 완성차 업체가 직접 참여하여 재제조함으로써 많은 건설 시공사와 수요처들에게 판매하고 있고, 수익성도 높아 완성차 제조 기업 중 재제조 사업으로 총 매출 중 20%를 차지할 만큼 적극적이다. 그러나 국내는 이제 2016년 건설기계 부품 재제조 협회를 창립하면서 음성적으로 재제조하여 왔던 기업을 양성화함은 물론 기반 인프라 구축을 통하여 선진 기업과의 조속히 격차를 줄여 나가고 있다. 또한 재제조에 대한 공정 기술을 개발함과 동시에 전국 인프라 구축을 통하여 산업의 활성화를 꾀하고자 건설기계 부품 산업의 발전 전략을 수립하여 본 기고에 제시하여 보았다.

• Journal of Energy Engineering
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• v.23 no.2
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• pp.102-113
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• 2014

This study analyzes whether the value-added structure of Korean bioenergy industry exhibits a virtuous cycle through the value chain(VC) within bioenergy firms, using a regression analysis based on a survey to Korean bioenergy companies. As a result, in Korean bioenergy companies, the R&D outputs positively influence an increase in production, and a decrease in production costs positively influences an increase in profit rates per sales. However, the government's supports for R&D is analyzed neither to lead an increase in corporates' R&D investments, nor to contribute to an increase in their R&D outputs. In addition, it turns out that an increase in production does not contribute to a decrease in production costs. Besides, it is analyzed that an increase in profit rates per sales does not contribute to an increase in production or an increase in the R&D investments. The virtuous cycle of the value chain in Korean bioenergy firms is, therefore, estimated to be weak. This study has a policy implication to need further efforts to create the virtuous cycle in the VC of Korean bioenergy industry.

• International Area Studies Review
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• v.15 no.3
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• pp.239-261
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• 2011

The cyclicality of productivity has been one of the essential issues in macroeconomics. Since Solow(1957) developed the dominant approach to the measurement of productivity growth, Solow's approach, which assumes the perfect competition, the constant returns to scale, and the full use of input factor has been modified particularly in Hall's(1990) and Basu's(1996) works. Their researches take account of market power, returns to scale, and variable factor utilization. This paper establishes the empirical model based on Hall's(1990) and Basu's(1996) models, estimates 4 types of Solow's reidual in manufacturing and 2 service industries over the period 1975:1-2010:4, and analyzes the cyclicality of measured productivity. The result proved the measured productivity to be procyclical in manufacturing industries and electricity and water industry, and in contrast to the Basu's, the variable factor utilization transformed the countercyclicality of measured productivity into its procyclicality in the Korean economy.

• Journal of Industrial Convergence
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• v.20 no.4
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• pp.23-30
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• 2022

Recently, with the development of artificial intelligence (AI) and deep learning, the importance of conversational artificial intelligence chatbots is being highlighted. In addition, chatbot research is being conducted in various fields. To build a chatbot, it is developed using an open source platform or a commercial platform for ease of development. These chatbot platforms mainly use RNN and application algorithms. The RNN algorithm has the advantages of fast learning speed, ease of monitoring and verification, and good inference performance. In this paper, a method for improving the inference performance of RNNs and applied algorithms was studied. The proposed method used the word group expansion learning technique of key words for each sentence when RNN and applied algorithm were applied. As a result of this study, the RNN, GRU, and LSTM three algorithms with a cyclic structure achieved a minimum of 0.37% and a maximum of 1.25% inference performance improvement. The research results obtained through this study can accelerate the adoption of artificial intelligence chatbots in related industries. In addition, it can contribute to utilizing various RNN application algorithms. In future research, it will be necessary to study the effect of various activation functions on the performance improvement of artificial neural network algorithms.

• Korean Chemical Engineering Research
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• v.55 no.6
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• pp.837-845
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• 2017

A recirculating integrated system composed of a fluidized biofilter filled with waste-tire crumb media fixed with return sludge from wastewater treatment facility of D dyeing industrial center, and a UV/photocatalytic reactor packed with calcined $TiO_2$ coated-glass beads as photocatalyst-support, was constructed and was run to treat authentic textile-dyeing wastewater from D-dyeing industrial center, which was mixed with an alkaline polyester-weight-reducing wastewater and a wastewater from sizing process. As a result, its total removal efficiency(RE(tot)) of $COD_{cr}$ and colors were ca. 81% and 55%, respectively. The synergy effect of the recirculating integrated system to enhance total removal efficiency(RE(tot)) of $COD_{cr}$ and colors were evaluated at most ca. 7% and 3%, respectively. The fluidized biofilter and the UV/photocatalytic reactor were responsible for ca. 94% and 6% of the total $COD_{cr}$ removal efficiency, respectively, and were also responsible for ca. 86% and 14% of the total color-removal efficiency, respectively. Thus, the degree of the UV/photocatalytic reactor-unit process's contribution to RE(tot) of color, was about 2.4 times of that to RE(tot) of $COD_{cr}$. Therefore, the UV/photocatalytic reactor facilitated the more effective elimination of colors by breaking down the chemical bonds oriented from colors of dyes such as azo-bond, than $COD_{cr}$. In addition, the effect of the removal efficiency of each unit process(i.e., the fluidized biofilter or the UV/photocatalytic reactor) of the recirculating integrated system on RE(tot) of $COD_{cr}$ and colors, was analysed by establishing its model equation with an analytic correlation.

• Journal of the Korean Geographical Society
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• v.38 no.6
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• pp.863-886
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• 2003

Internet is the most important element in the emergence of the Internet economy, which derives the creation of new firms and employment, and brings about the new ways of marketing and business. The emergence of the Internet economy and the rapid growth of the Internet industry have a great deal to changes in the spatial economy. Korea has experienced a rapid growth of the Internet industries, but few geographical studies have been done to explain the impact of the development of the Internet industries on the spatial economy. This research explored how Korea has developed as a nation of the strong Internet economy in terms of driving forces by demand and supply side. This research tried to build a data set for the Internet industries with the introduction of a new classification scheme and a measurement. The most important finding from this research was the spatial concentration of the Internet industries toward Seoul at the national level and toward the Gangnam area within Seoul. The rise of Internet industries has added attractiveness to Seoul which enjoys a kind of cumulative and circular advantages.

• Journal of Digital Convergence
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• v.13 no.12
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• pp.13-21
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• 2015

Ongoing advances in wireless broadband technologies can affect all of industrial society. As new wireless broadband technologies emerge, they will improve competition between established industries and their current services and produce new industries and new converged services. This paper analyzes the trend of next-generation wireless broadband and suggests ways of activating the industry further. To this end, we analyze the trend for previous wireless broadband industries and find out three influential factors (content, wireless network technology, and service) that will produce the continued growth of wireless broadband. Using these three factors, we propose a network technology-driven growth model. Based on that model, we offer activation plans for next-generation wireless broadband industries. This study thus provides an insightful perspective for next-generation wireless broadband industries by establishing additional useful guidelines for developing wireless broadband industries in the future.

• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.49-57
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• 2013

Recently, recycling of the industrial by-products has been an important issue of the Yeosu bay, where large industrial complex is located. Major industrial by-products which are produced from Yeosu industrial complex area are phosphogypsum and flyash, which are about 82% and 10% of the 1.6 million tons industrial by-products. Moreover since the Yeosu industrial complex is located at seaside, phosphogypsum has been pointed as cause of serious environmental contaminant from the regional society. Therefore recycling study can't be delayed anymore. In this paper, artificial aggregate was manufactured by non-sintering process from industrial byproducts - e.g., phosphogypsum and slag - as a geotechnical drainage material. To show the feasibility of the artificial aggregate as a geotechnical drainage material, geotechnical experiments including particle size analysis, permeability test, and large scale direct shear test were carried out. Test results show that the permeability of the artificial aggregates range from $6.94{\times}10^{-1}cm/sec$ to $8.86{\times}10^{-1}cm/sec$, which is much larger value than those are required for the drainage material from the construction specification in Korea, and the friction angle of the artificial aggregate is as large as that of sand in water immersion conditions. From the test results, it was concluded that artificial aggregate made from industrial by-products can be used successfully as a geotechnical drainage material.

• Journal of the Korean Recycled Construction Resources Institute
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• v.12 no.1
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• pp.82-93
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• 2024

Since the cement industry generates more than 60 % of CO₂ during the clinker production process, supplementary cementitious materials are used worldwide to reduce CO₂ efficiently. Mainly used supplementary cementitious materials such as blast furnace slag and fly ash, which are used in various industries including the cement industry, concrete admixtures, and ground solidification materials. However, since their availability is expected to decrease in the future according to the carbon neutrality strategy of each industry, new supplementary cementitious materials should be used to achieve the cement industry's goal for increasing the additive content of Portland cement. Limestone is a material that already has a large amount in the cement industry and has the advantage of high grinding efficiency, so overseas developed countries established Portland limestone cement standards and succeeded in commercialization. This study was an experimental study conducted to evaluate the possibility of utilizing domestic PLC, the effect of fineness and replacement ratio on the physical properties of cement was investigated, and the environmental impact of cement was evaluated by analyzing CO₂ emissions.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 1998.05a
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• pp.57-62
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• 1998

미분탄 연소로는 산업현장, 특히 화력발전플랜트에서 널리 사용되는 설비로서 국내외의 많은 현장에서 적용되고 있다. 이에 따라 연소로내의 난류유동장과 연소현상 등에 대한 이해 및 이를 설계에 응용하고자 하는 노력들이 진행되고 있다. 특히 연소로내의 복사열전달 특성의 이해를 통한 연소로 크기 결정 및 수순환 해석, 화로출구온도 계산에 의한 대류전열부 설계 등에 적용하고자 시도하고 있다. (중략)