• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.179-182
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• 2008

It needs to consider of turns during a path-finding on real road network. Because a car is delayed by waiting a traffic signal and decreasing speed when drived in a turn road such as cross road and slip road. If a straightness of a path is increased, a real cost of traveling should be able to decrease. An older method, the algorithm with Turn Heuristic, considered of this case. The algorithm, that differently gave weights to left, right and U-turns, improved a straightness of a path, but increased a cost of exploring. In this paper, we propose a improved Turn Heuristic Algorithm. Proposed algorithm uses Dynamic Turn Heuristic. It is able to more decrease a cost of exploring than older method by using the Turn Heuristic in a part of path-finding.

• 한국HCI학회:학술대회논문집
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• 2006.02a
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• pp.1093-1098
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• 2006

VR 엔진은 일부 입력장치에 대해서만 제한적으로 지원하기 때문에, 개발자가 원하는 입력장치를 사용하지 못하는 경우가 있으며, 가격 또한 고가이기 때문에 특수한 입력장치를 사용하기 위해, 다른 VR 엔진이나 별도의 옵션을 구매하기에는 경제적인 부담이 많이 든다. 이러한 문제를 해결하기 위해 본 논문에서는 개발자가 사용하고자 하는 입력장치와 VR 엔진의 호환을 위한 랩퍼 클래스를 제안한다. 개발한 랩퍼 클래스는 VR 엔진에서 조이스틱을 제어할 수 있는 조이스틱 클래스와 USB 캠을 통하여 영상을 획득하기 위한 USB 캠 클래스이다. 조이스틱 클래스는 입력장치 클래스를 상속받은 후 DirectX 를 이용하여 입력장치를 셋업 하고, 입력장치의 데이터 값을 처리한 후 VR 엔진의 API 로 값을 넘겨주기 전에 후킹하여 조이스틱을 제어할 수 있다. USB 캠 클래스는 VFW(Video for Window)를 사용하여 캠의 영상을 획득하여 버퍼에 저장한 후 VR 엔진의 디스플레이 버퍼에 값을 넘겨서 캠의 영상을 VR 엔진에서 디스플레이 할 수 있다. 이러한 방법을 통해 조이스틱, USB 캠 같은 입력장치를 VR 엔진과 호환할 수 있으며, 다른 종류의 입력장치에 대하여서도 본 연구에서 개발한 랩퍼 클래스를 상속받아 사용할 수 있다. 본 논문에서 사용한 VR 엔진은 Vega Prime 엔진이며, Vega Prime 엔진의 API 에 개발한 랩퍼 클래스를 추가하여 드라이빙, 영상인식 시뮬레이터를 개발한 결과, 효과적이고 경제적으로 입력장치의 연동이 가능함을 확인할 수 있었다.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.317-326
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• 2007

We propose more enhanced heuristic for the GOSST(Grade of Services Steiner Minimum Tree) problem in this paper. GOSST problem is a variation of Steiner Tree problem and to find a network topology satisfying the G-Condition with minimum network construction cost. GOSST problem is known as one of NP-Hard or NP-Complete problems. In previous our research, we proposed a heuristic employing Direct Steiner Point Locating strategy with Distance Preferring MST building strategy. In this paper, we propose new Steiner point locating strategy, Zigzag Steiner point Locating strategy. Through the results of out experiments, we can assert this strategy is better than our previous works. The Distance Zigzag GOSST method which hires the Distance Preferring MST building strategy and Zigzag Steiner point Locating strategy defrays the least network construction cost and brings 31.5% cost saving by comparison to G-MST, the experimental control and 2.2% enhancement by comparison to the Distance Direct GOSST method, the best GOSST method in our previous research.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.385-388
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• 1996

Accumulation of soil chemical components in plastic-house is serious problem in Korea. This study was carried out to solve the problem by comparing the contents of soil chemical properties in plastic-house with that of upland field. The content of organic matter and available $P_2O_5($ in plastic-house soil were higher than that of upland field. Particularly, organic matter content in plastic-house soil (43g/kg) was 1.7times higher than that of upland soil (26g/kg), and content of available $P_2O_5($ (893mg/kg) in plastic-house: soil was 4.9 times higher than that of upland soil(183mg/kg). The content of exchangeable K, Ca and Mg in plastic-house soil were 0.5, 6.8 and 1.6cmol/kg and that of upland field soil were 0.5, 2.3 and 2.5cmol/kg, respectively.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.9 no.4
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• pp.309-317
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• 2015

In this paper, we proposed the standard test specification for safety and function of hiking stick for the elderly. We have concluded nine factors representing specification of hiking stick through analysis of hiking patents and research papers, products survey of business market, case studies for damaged hiking stick and expert surveys. To test the factors, we designed three different kinds of apparatus to examine twist resistance, stick and tip durability and stick straightness. The sample of hiking sticks purchased from market based on Naver sales ranking top to fifteenth. As a result, we concluded six-standard test specification based on eccentric load, adjustable parts load, hand strap load, basket load, tip load and pull load of hiking stick.

• The Journal of the Korea Contents Association
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• v.7 no.11
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• pp.182-192
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• 2007

The plastic furniture made of new materials has enriched and broadened our everyday life not only through development of manufacture but also through consumptions since 1960's. In relation as well to the need of reducing energy consumption and contributing to environment, the weight of plastic materials has raised concerns in recently. Our rapidly changing lifestyle demands a new design that meet recognition of inflection. In conclusion, as we are preparing to enter into the 21st Century, we should go forward with hope and do so with dispatch-dazzling all of us with boldness, thinking imaginatively, transform indifference into action, moving things to the next level in plastic industries. From this study we have found that it would be useful to understand that the development of technological plastic materials for seat furniture has enabled designers to create more and more sophisticated design in our millennium life.

• Journal of Biomedical Engineering Research
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• v.20 no.5
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• pp.609-616
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• 1999

심폐바이패스시 발생할 수 있는 튜브 마모 및 파쇄는 롤러펌프의 반복되는 압박에 의해 롤러펌프에 장착된 튜브 내벽에 균열이 생기고 이로 인해 미세한 비생물적 조각들이 혈액중으로 떨어져 나가는 현상을 말하는데, 임상적으로 치명적인 색전증을 초래할 수 있다. 그러나 아직 롤러펌프 튜브로 사용되는 PVC 및 실리콘 튜브 중 어느 쪽이 마모 및 파쇄 관점에서 더 우수한지는 체계적으로 밝혀지지 않고 있다. 이에 본 연구는 두 종류의 튜브를각각 일정 기간 롤러펌프에 장착하여 작동시킨 뒤 튜브내외면을 육안 및 주사형 전자현미경으로 관찰하였다. 즉 PVC 및 실리콘 튜브 (내경 1/2 인치의)들을 미리 정해진 폐쇄도 조절에 의해 폐쇄 회로 심폐비이패스 롤러펌프 헤드에 장착시키고 4.500ml/min에서 각각 4차례씩 1,2,4,6 시간 작동시켰다. 파쇄에 의한 색전 관찰 실험에서는 회로 중간에 동맥여과기를 설치하고 각각 6,9시간 씩 롤러펌프를 작동시켰다. 실험 후 튜브 및 여과기들을 수거한 후 육안 및 주사형 전자현미경 분석을 시행하였다. 실험후 튜브 및 여과기들을 수거한 후 육안 및 주사형 전자현미경을 분석을 시행하였다. 튜브 외부의 육안 관찰 결과 일반적으로 실라스틱 튜브에서의 외부 마모가 PVC 튜브에 비해 현저하였다. 주사형 전자현미경 관찰에서 PVC 튜브에서의 홈은 좁으면서 경계선이 뚜렷한 특징을 보였고 3시간 이상 롤러와 접촉한 튜브들에게서는 깊은 균열이 간헐적으로 관찰되었다. 반면, 실라스틱에서의 홈은 좁으면서도 경계선이 뚜렷한 특징을 보였고 3시간 이상 롤러와 접촉한 튜브들에게서는 깊은 균열이 간헐적으로 관찰되었다.반면 실라스틱에서의 튜브들에서는 홈이 상대적으로 넓고 경계가 덜 명확했으며, 특징적으로 V 자 모양의 융기부들이 간헐적으로 관찰되었다. 실라스틱 및 PVC 튜브 모두에서 50u 전후의 Craters 가 간헐적으로 관찰되었다. 여과기의 여과망에 대한 주사형 전자현미경 분석 결과 실라스틱과 PVC 튜브 실험군 모두에서 색전입자로 의심되는조각들이 발견되었으나 두군간 정량적 비교는 어려웠다. 결론적으로 롤러펌프에 의한 튜브 마모 및 파쇄현상은 실리콘 및 PVC 튜브의 재질에 따라 그 양상에는 차이가 있으나 임상적인 측면에서는 어느 쪽도 상대적인 우수성이 입증되지 못하였다.

• Resources Recycling
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• v.17 no.1
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• pp.43-50
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• 2008

In this study, we carried out the research on triboelectrostatic separation for materials separation of PET & Nylon recovered to waste plastic beer bottle. From the research on charging characteristic for choice of charging materials, it was found that PMMA was optimum charging material to make high charging amount with opposite polarity for PET & Nylon in waste plastic beer bottle. Therefore, we manufactured a charger of pipe line and cyclone type using PMMA material for separation of PET and Nylon. At optimum test conditions that used PMMA pipe line and cyclone charger developed in this study, we developed a triboelectrostatic separation technique that can separate PET plastic up to grade of 99.6% and recovery of 88.2%. We established new separation technology that can recycle the PET and Nylon recovered from waste plastic beer bottle.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.425-432
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• 2021

In this paper, We produced supporting for ginseng cultivation facilities as a material recycling product of CPW(Complex Plastic Wastes, CPW) from households. And we analyzed the characteristics of material recycling products according to the amount of r-LDPE(Recycled low density polyethylene, r-LDPE) used. As a result, as the amount of recycled LDPE used increa sed, the tensile strength a nd elonga tion of ma teria l recycled products using CPW increa sed, but a sh decrea sed. When the recycled r-LDPE usage is 5% or more, the physical properties of the material recycling product using CPW stably satisfy the quality standard (GRM 3093-2021) of supporting for ginseng cultivation facilities.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.59-64
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• 2011

Clogging in drainage pipe is one of the important problems, so it needs a remedy urgently. Recently, scale in drainage pipe is removed by water jet cleaning and other treatment. But these treatments need much cost and regular management. The principal component of scale in drainage pipe is $CaCO_{3}$. It was observed the setting of $CaCO_{3}$ by some kind of analysis such as SEM, XRD, visual and weight measuring analysis to solve these problems and prevent setting formation in drainage pipe. As a result, in case of magnetic, particle shape of $CaCO_{3}$ is changed Aragonite from Calcite. Also in case of Quantum Stick, the amount of scale is reduced by expert inspector's result. As a whole, Magnetic treatment and Quantum Stick have the effect for protecting of scale precipitation.