• Feed Journal
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• v.2 no.5
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• pp.74-79
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• 2004

최근 3년간 세계 식량 재고량이 매년 1억톤 가량씩 감소하면서 세계적인 식량위기가 다시 화두가 되고 있는 21세기를 살아가는 우리에게 먹고 사는 문제는 고민해야 될 과제임이 분명하다. 특히 식량 자급률이 경제성장에도 불구하고 계속 30% 내외로 극히 불안정한 우리나라의 입장에서 보면 농축산업분야에 종사하는 이들은 미래에 대한 무한 책임감을 느끼지 않을 수 없다. (중략)

• Proceedings of the KAIS Fall Conference
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• 2004.11a
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• pp.80-82
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• 2004

본 논문에서는 폐목재의 재활용을 위한 파쇄기의 경계조건과 하중조건을 적용하여 유한요소법에 의한 ANSYS로 구조해석과 모달해석을 수행하여 변위(displacement), 응력(stress), 변형률(strain)을 구하고 구조적 타당성을 검토하였다. 이는 안전성을 고려한 설계의 기초자료가 되며 고유진동수(natural frequency)를 구하여 모터의 회전을 제어함으로서 공진(resonance) 현상을 피하는데 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2000.10b
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• pp.146-148
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• 2000

본 논문은 최근 물리적인 업무공간의 확보에 많은 비용을 부담해야 하는 상황에서 웹기반의 가상 오피스 시스템인 Extranet을 활용하여 정보의 공유와 정보전달을 위한 다양한 매체로서 활용이 가능하도록 구현하였다. 업무 전반에 인터넷의 이용률이 급격히 증가하며 업무 담당자간, 작업 그룹간의 원활한 커뮤니케이션 시스템이 필요하게 되었다. 영상을 이용한 다자간 통신 시스템의 경우 하드웨어 시스템의 확장으로 높은 추가 비용이 필요하다. 최근 커뮤니케이션의 도구로 다양한 형식의 통신 수단을 이용하고 있으나 정보의 저장과 재활용의 측면에서 많은 문제점을 가지고 있다. 이러한 문제점을 해결하기 위하여 웹 기반의 통신망을 작업 그룹간의 Extranet System을 설계하고 구현하였다.

• Clean Technology
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• v.25 no.4
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• pp.289-295
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• 2019

Though the usage of vinyls and plastics produced from fossil fuels has been increasing in the world, the eco-friendly domestic disposal or recycling of waste vinyls has to be executed because the migration or importation of waste vinyls or waste plastics are globally prohibited. Even though the eco-friendly domestic disposal or recycling of waste vinyls and waste plastics should be developed, promising eco-friendly recycling methods are few because there are extraneous substances in waste vinyls and waste plastics. Also, conventional incineration and landfill methods result in secondary contamination and then increase disposal costs. Therefore, the selective elimination of extraneous substances or other materials included in waste vinyls and waste plastics could make valuable recycling or reuse possible. In particular, the novel hybrid process in which crushing and screening are simultaneously conducted in a rotary kiln type reactor can domestically maximize the material recycling or reuse. In this study, the feasibility study for a crushing/screening hybrid process developed in Korea was performed and evaluated in case of thermal recycling (TR) and material recycling (MR). The effect of various subsidies on economic efficiency was especially evaluated by means of domestic recycling plans. The incentive revenues from waste vinyl recycling and the incineration share of waste vinyls affected the net present values and internal rate of returns of the hybrid process.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.317-324
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• 2020

Plastic wastes generated from domestic waste are separated by mixed discharge with foreign substances, and the cost of the separation and screening process increases, so recycling is relatively low. In this study, as a fundamental study for recycling mixed plastic wastes generated from domestic waste into concrete aggregates, changes in concrete properties according to the plastic waste types and the substitution rate were evaluated experimentally. The mixed plastic waste aggregate(MPWA) was found to have a lower density and a higher absorption rate compared to the coarse aggregate with good particle size distribution. On the other hand, the single plastic waste aggregate(SPWA) was composed of particles of uniform size, and both the density and the absorption rate were lower than that of the fin e aggregate. It was found that the MPWA substitution concrete did not cause a material separation phenomenon due to a relatively good particle size distribution even with the largest amount of plastic waste substitution, and the amount of air flow increased little. The compressive strength and flexural strength of the PWA substitution concrete decreased as the amount of substitution of the PWA increased due to the low strength of the PWA, the suppression of the cement hydration reaction due to hydrophobicity, and the low adhesion between the PWA and the cement paste. It was found that the degree of deterioration in compressive strength and flexural strength of concrete substituted with MPWA having good particle size distribution was relatively small.

• Resources Recycling
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• v.29 no.2
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• pp.28-36
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• 2020

To enhance the recycling rate of wasted glass bottles toward recycled aggregates, the study would decide optimal comminution equipment based on the particle size distribution, aspect ratio and equipment energy analysis. The impact, compress and abrasion is type of generated force by comminution. So, hammer crusher, shredder, roll crusher and ball mill have been selected because they have characteristic which is each type of force. As a result of the particle size analysis of each product, only the shredder product satisfied concrete and asphalt aggregate quality standard condition. Also, as a result of aspect ratio analysis using Imaging software program (Image J, National institute of health), most of size fraction is confirmed under 1.6 value. It was confirmed that the product has low dangerousness and satisfying to shpage index. Also, the particle reduction ratio against input energy of shredder product was the most high. Therefore, we can decide that the optimal equipment which applicable for comminuting waste glass bottle in certain particle size under 10mm is shredder. The result of study will make contribution to increasing energy efficiency of comminution processing and competitiveness of product.

• Journal of the Korea Concrete Institute
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• v.19 no.2
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• pp.233-239
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• 2007

The main objective of this study was to evaluate the effect of recycled PET fiber made from waste PET bottle on the control of plastic shrinkage cracking of cement based composites. PET is blown as a plastic material and used in a variety products such as a beverage bottle. However, waste PET bottles are thrown after the usage, raising huge problems in terms of the environment. Thus, the research on the method to recycle the PET bottles indicates important aspects in environment and economy. The method to recycle waste PET bottles as a reinforcing fiber for cement based composites is one of effective methods in terms of the recycle of waste PET bottles. In this research, the effect of recycled PET fiber geometry and length on the control of plastic shrinkage was examined through thin slab tests. A test program was carried out to understand the influence of fiber geometry, length and fiber volume fraction. Three type of recycled PET fibers including straight, twist crimped and embossed type. Three volume fraction and two fiber length were investigated for each of the three fiber geometry. Test results indicated that recycled PET fibers are effective in controlling plastic shrinkage cracking in cement based composites. In respect to effect of length of fiber, longer fiber was observed to have efficient cracking controlling with low volume fraction in same fiber geometry while shorter fiber controled plastic shrinkage cracking efficiently as addition rate increase. Also, embossed type fibers were more effective in controlling plastic shrinkage cracking than other geometry fiber at low volume fraction. But, for high volume fraction, straight type fibers were most effective in plastic shrinkage cracking controlling in cement based composites.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.545-546
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• 2009

This study was performed to prove the possibility of utilizing short plastic fibers made for recycled polyethylene terephthalate (RPET) as a structural material. To measure of crack control capacity, restrained drying shrinkage cracking test was performed. In order to verify the capacity of RPET fiber, it was compared with poly propylene (PP) fiber, most widely used short synthetic fiber, for fiber volume fraction of 0%, 0.5%, 0.75%, and 1.0%.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.366-370
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• 2010

허니컴 코아 구조는 강성과 강도가 뛰어나 건축물의 내장재 등 많은 분야에서 활용되고 있다. 특히 허니컴 종이는 생산 단가가 낮으며 재활용이 가능하여 환경오염을 일으키지 않는다. 그러나, 종이 재료의 특성상 화재에 취약하여 난연화 할 필요가 있다. 본 연구에서는 방화문 내장재 및 포장재에 보편적으로 사용되는 허니컴 중이의 난연 처리 방법에 따른 난연 성능을 평가하였다. 연구 대상으로는 난연종이로 제작된 허니컴과 실험실에서 제작된 방염 필름을 부착한 허니컴, 난연제 함침을 통해 제작된 허니컴, 난연제 함침 후 방염 필름을 부착한 허니컴을 포함해 총 4종에 관한 난연 성능을 비교하였다. 그 결과, 난연제를 함침한 허니컴 종이가 가장 낮은 열방출률을 보여주었으며, 방염 필름 부착은 착화 시간 지연에는 효과가 있었으나 열방출률에 부정적인 영향을 미치는 것으로 확인되었다.

• Proceedings of the Korean Information Science Society Conference
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• 2001.10a
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• pp.292-294
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• 2001

제품 개발을 담당하는 부서에서, 다양한 이유로 핵심인력이 빠져나간다. 이때마다 제품개발 현장에서는 심각한 지식 누수현상이 나타나게 된다. 따라서, 지식 누수 현상을 방지하기 위한 방법은 기업 내부에 존재하는 핵심인력의 노하우를 형식지로 저장해 관리하는 것이다. 제품을 개발을 담당하는 부서에는 수많은 문서들이 존재한다. 특히 품질 관리 문서는 제품개발과 관련된 핵심인력의 노하우가 농축되어있는 지식이다. 그래서 많은 기업에서는 기업내부에서 발생하는 그 지식을 관리하고 재활용하고자, 문서관리를 위한 시스템을 도입, 사용하고 있다. 그러나 설계 지식의 공유를 지원하는 시스템을 갖추었어도, 단순히 설계지식을 저장해놓은 경우가 많아, 개발자는 필요한 자료를 다시 선정해야 하는 문제가 발생한다. 이는 개발자에게 있어서 부담이 되며, 풍부한 지식활용률을 떨어뜨리게 만드는 한 요인이 된다. 본 논문에서는 이 문제를 해결하기 위해, 온톨로지를 기반으로 문서를 분류하고, 이 온톨로지에 정의된 키워드를 바탕으로 새로운 지식을 자동적으로 추론하여, 제품에 대한 기술적 지식을 가지고 검색하게 함으로서 필요 없는 검색 결과를 최소화 하고, 설계자의 지식 활용률을 높이고자 하였다.