• 한국지열·수열에너지학회논문집
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• 제13권4호
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• pp.21-30
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• 2017

Recently, It has increased the importance of building energy saving. Pipe insulation as well as building envelope insulation is to improve energy efficiency and reduce the energy loss. However, there continues to use the old standard for pipe insulation that is one of the most important elements in energy savings in buildings. The purpose of this study is to propose suitable pipe insulation thickness for reducing building energy use. The study also reviews pipe insulation thickness standard in accordance to Korea standard, ASHRAE 90.1 and BS5422 and analyzed through thermal simulation. As a result, it is necessary to apply the performance design method of the pipe insulation thickness to reduce the energy loss of the piping.

• 방사선산업학회지
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• 제5권2호
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• pp.159-164
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• 2011

A variety of natural polymers have been used as tissue engineering scaffolds, drug delivery system, and cosmetic materials due to their higher biocompatibility and water uptake. As a major component of extracellular matrix, hyaluronic acid consisting of D-glucuronic acid and N-acetylglucosamine has been popularly used as a hydrogel material. Even though it has good properties to be used in the tissue engineering and cosmetic industry, its higher viscosity has limited a potential use in a variety of applications; only low content should be applied in preparing above products. In the present study, we investigated the effect of electron beam irradiation on the properties of hyaluronic acid. Hyaluronic acid paste containing low contents of water changed to solution after electron beam irradiation ranging from 1 to 10 kGy, which didn't exhibit any alteration of surface properties and morphological change after freeze-drying. However, its viscosity was significantly decreased as absorbed dose increased, which was approximately one by hundred in comparison with the viscosity of original hyaluronic acid solution with same concentration. In addition, it can still interact with positive charged chitosan generating polyelectrolyte complex. Therefore, only viscosity was decreased after electron beam irradiation, whereas other properties of hyaluronic acid maintained. Consequently, these hyaluronic acids with lower viscosities can be used in a variety of applications in tissue engineering, drug delivery, and cosmetic industry.

• 방사선산업학회지
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• 제5권2호
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• pp.131-135
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• 2011

In this study, we fabricated the HDPE and ${\alpha}-Al_2O_3$ composites with PE-g-MA as a function of the ${\alpha}-Al_2O_3$ nanopowder weight ratios. The electron beam irradiations on HDPE/${\alpha}-Al_2O_3$ composites were carried out over a range of absorbed doses from 20 to 200 kGy to make three-dimensional network structures. The mechanical properties were characterized using UTM for confirming the changes of the flexural strength and tensile strength. It was observed that the mechanical properties of HDPE were enhanced by the addition of ${\alpha}-Al_2O_3$. However, the strength of the 5 wt% ${\alpha}-Al_2O_3$ added composites decreased due to the nano-powder aggregation. The mechanical properties of composites were increased as increasing the electron beam irradiation up to 150 kGy. We believed that the electron beam irradiated HDPE/${\alpha}-Al_2O_3$ composites can be a good candidate for a variety of industrial applications.

• 방사선산업학회지
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• 제6권2호
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• pp.159-164
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• 2012

Bacterial cellulose (BC) is generated from citrus gel by Gluconacetobacter hansenii TL-2C. BC has good properties such as high-burst pressure, high-water contact and the ultrafine highly nanofibrous structure of mimic natural extracellular matrix (ECM) for tissue engineering. In this study, acrylic acid (AAc) was grafted onto BC surfaces under aqueous conditions using gamma-ray irradiation, and then immobilized gelatin onto AAc-g-BC. The characterization of scaffolds was performed by scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), toluidine blue O (TBO) assay. Morphology of gelatin and AAc incorporation onto BC nanofibers did not changed. Our study suggests that gelatin-immobilized BC nanofibers scaffold has a potentiality to fabricate 3D nanofibrous scaffolds for tissue engineering.

• 방사선산업학회지
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• 제6권1호
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• pp.11-15
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• 2012

This study confirmed the cytotoxicity and anti-inflammatory activities of natural herbal extracts (HE) including Eucommia ulimoides and Ulmus davidiana against human mast cell (HMC-1). HE was extracted with distilled water (at $75^{\circ}C$) and then freeze-dried for 5 days. Finally, the HE was sterilized by gamma radiation with $^{60}Co$ ${\gamma}$ source at room temperature. Cytotoxicity of the HE against HMC-1 cell was measured using cell counting kit-8 (CCK-8) assay. In addition, inflammatory cytokines such as $TNF-{\alpha}$, IL-6 and IL-8 were evaluated by ELISA kit on the HMC-1 cells with calcimycin A23187 and phorbol 12-myristate 13-acetate (PMA). The results showed that HE had no toxicity and reduced $TNF-{\alpha}$, IL-6, IL-8 response on HMC-1 cells.

• 디지털융복합연구
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• 제8권4호
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• pp.47-57
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• 2010

본 연구의 목적은 광주지역에서 신재생에너지 산업의 인력양성방안에 대한 효과적인 정책적 대안을 제시하고자 하였다. 오늘날 우리나라의 경제는 새로운 발전모형을 찾아야 하는 사회 경제발전의 패러다임의 변화를 맞이하고 있다. 이러한 흐름에 부응하여 본 논문은 광주지역이 녹색성장인력양성이라는 목적 달성을 위해 가장 적합한 지역이라는 것을 제시하였다. 첫째, 신재생에너지산업을 활성화하기 위해 천혜의 자연환경을 갖추었다는 것이다. 둘째, 새로운 산업을 추동하기위해 우수한 인적자원을 보유하고 있다는 것이다. 따라서, 신재생에너지산업을 활성화하기 위한 장 단기적인 다양한 인력 양성정책을 추진할 필요가 있다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.1-7
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• 2015

The industry has rapidly growth and energy supply technology advanced are become main factor which to contribute of the harmonic losses. This problem is one aspect that may affect the capability of the transmission line and also to the efficiency of electricity. This paper proposes a new scheme to allocate the cost pertaining to transmission loss due to harmonics. The proposed method, called as Generalized Harmonic Distribution Factor, uses the principle of proportional sharing method to allocate the losses among the transmission users especially for industry consumers. The IEEE 14- and 30 bus test system is used to compare the proposed method with existing method. The results showed that the proposed method provided a scheme better in allocating the cost of transmission loss, which could encourage the users to minimize the losses.

• Asia Pacific Journal of Business Review
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• 제2권1호
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• pp.21-52
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• 2017

Nowadays every technology is becoming smarter. Consequently, intensive use of ICT in the whole industries and cities enables a sustainable approach to meet enormous productivity, efficiency, transparency and conservation of natural recourses. Likewise, the role of ICT in terms of controlling, monitoring in the energy industry allows integrating potential renewables, bulk energy conservation and reliable optimized operation in the entire system. In this paper outlines challenging issues in renewable energy integration in Mongolia and proposes potential recommendations and conclusions. The author investigated the main technologies used in energy industry mainly smart grid, challenges and policy aspect in Mongolian energy sector by using the primary and secondary approach with case studies and literature based methodologies. Based on the policy aspect and current implementation of smart grid, the paper tries to address the readiness for the main application and future potential ICT driven applications. Furthermore, it concluded that ICT convergence is demanded to overcome the current vulnerabilities and significant momentum to leave behind by using its potential energy recourses and favorable geographical state. Policymakers may find this study useful, as it answers the question of whether ICT investment can ultimately reduce energy consumption and may aid in future planning. Even tough, in order to develop a smart grid and integrating renewables firstly set an appropriate market structure, ICT will key enabler to make energy system more profitable and sustainable. Regarding the result of this study, ICT deployment contribution is a huge demand for future opportunities energy in Mongolia.

• 기술혁신학회지
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• 제19권4호
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• pp.822-847
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• 2016

미래 산업 유지를 위하여 세계적으로 지속가능한 에너지의 중요성이 부각되고 있다. 다양한 신재생 에너지 중 수소에너지는 청정에너지로서 각광받고 있다. 이에 본 연구는 수소에너지산업 인프라 구축시에 필요한 전략 수립을 위하여 SWOT/AHP 분석을 적용하였다. 우선 수소에너지 산업 인프라 구축시 요구되는 요인들을 추출하였고, SWOT matrix를 재구성하기 위하여 전문가의 의견을 조사하였다. 쌍대비교를 하여 개발된 요인들의 상대적 중요도를 알기 위하여 AHP 분석을 실시하였다. SWOT 분석과 AHP 분석을 적용하여 얻은 연구 결과를 기초로 하여 향후 수소에너지산업 인프라와 관련된 전략 계획의 수립 방안을 제시하였다.

• 에너지공학
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• 제18권2호
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• pp.75-86
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• 2009

본고는 한국 에너지 기업의 기술수준을 세계 최고수준과 대비하고, 이러한 기술수준을 결정하는 요인들을 기술경제이론과 경영자원의존이론을 통해 살펴보았다. 한국 에너지기업의 세계최고수준 대비 기술수준은 기술경제적 요인인 규모의 경제효과와 전방기업과 후방기업간 협력적 관계 등에 의해 긍정적 영향을 받고 있는 것으로 분석되었다. 반면, 국내시장의 경쟁정도, 연구개발투자 비중, 연구개발인력 비중 등은 국내 에너지기업의 세계 최고수준 대비 제품기술수준에 영향을 미치치 못하고 있는 것으로 분석되고 있다. 이 분석에서 얻을 수 있는 정책적 시사점은 한국 에너지기업의 기술수준을 제고하기 위해서는 국내시장을 더욱 경쟁적으로 전환해야 하며, 연구개발투자와 연구개발인력 등을 확충하고 부가가치사슬 상에서 전방기업과 후방기업 간 공동발전을 촉진하는 정책을 추진할 필요가 있다는 것이다.