• 한국잠사곤충학회지
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• 제54권1_2호
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• pp.17-22
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• 2016

사육환경은 아메리카동애등에(Hermetia illucens) 의 산란에 직접적으로 영향을 준다. 본 연구에서는 아메리카동애등에 성충사육상의 크기와 산란처에 따른 산란 선호성을 조사하였다. 성충사육상의 높이를 2 ｍ로 고정시키고 가로 세로의 길이만 다르게 제작하였으며 20,000 개체의 성충을 사육상에 투입하였다. 평균 난괴수는 가로, 세로 길이가 $4{\times}4m$인 사육상에서 평균 895.4 난괴, $2{\times}1m$ 사육상에서 876.3 난괴 그리고 $1{\times}1m$ 사육상에서 62.3난괴를 산란하였다. 아메리카동애등에 성충사육상의 재질에 따른 산란난괴수를 비교한 결과 모기장망사육상에서는 820.7 난괴를 산란하였고 비닐재질사육상에서는 604.3 난괴를 산란하였다. 성충산란처의 종류별로는 갈색골판지에 평균 41.0 난괴 녹색 플로랄폼은 326.6 난괴를 산란하였으며, 녹색테이프를 붙인 골판지에는 135.2 난괴를 산란하였다. 산란처로 플로랄폼과 갈색 골판지에 플로랄폼을 겹친 산란처에서는 유사한 산란결과로 평균 64.7과 57.7난괴를 산란하였다. 산란처 구멍의 직경이 6 mm와 4 mm에서는 29.0과 48.2 난괴를 산란했다.

• 펄프종이기술
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• 제39권5호
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• pp.52-57
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• 2007

Corrugated fiberboard is a representative packaging material because of high compressive strength and stiffness in spite of light weight. The flutes of corrugated fiberboard are various depending on the height and the number per unit length of flute. The corrugated fiberboard with microflute like E, F or G with low height less than 1.5 mm has developed. Because it has some advantages including higher stiffness and lower requirement of fiber than carton board, it has a possibility to replace folding box board. Its consumption has been increased with the various applications like graphic packaging. As microflute has the different geometry from other conventional flutes, it can show the different behavior in testing and it may require a new testing method. In this study, we evaluated the edgewise compressive strength of the corrugated fiberboard with microflute according to ISO and other standard test methods. And the effect of specimen shape and platen compression rate was examined. From this study, we found that ISO methods was suitable and reasonable methods for corrugated fiberboard with microflute.

• 대한기계학회논문집
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• 제18권4호
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• pp.1019-1030
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• 1994

Natural convection heat transfer from a horizontal ice cylinder immersed in quiescent cold pure water was studied experimentally. The experiment was conducted for the ambient water temperatures ranging from $2.0^{\cric}C$ to $10.0^{\circ}C$. The flow fields around an ice cylinder and its melting shapes were visualized and local Nusselt numbers obtained. Especially, its attention was focused on the density maximum effects and stagnation point Nusselt number. From the visualized photographs of flow fields, three distinct flow patterns were observed with the ambient water temperature variation. The melting shapes of ice cylinder are various in shape with flow patterns. Steady state upflow was occured at the range of $2.0^{\circ}C \leq T_{\infty} \leq 4.6^{\circ}C$ and steady state downflow was occured at $T_{\infty} \geq 6.0^{\circ}C$. In the range of $4.7^{\circ}C < T_{\infty} < 6.0^{\circ}C$, three-dimensional unsteady state flow was observed. Especially, the melting shapes of ice cylinder have formed the several spiral flutes for the temperatures ranging from $5.5^{\circ}C$ to $5.8^{\circ}C$. For upflow regime, the maximum stagnation point Nusselt number exists at $T_{\infty} = 2.5^{\circ}C$ and as the ambient water temperature increases the Nusselt number decreases. At ambient water temperature of about $5.7^{\circ}C$, Nusselt number shows its minimum value.

• 대한치과의사협회지
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• 제53권2호
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• pp.132-142
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• 2015

Purpose : The objective of this research was to investigate an optimization of drill design factors for implant stability and efficacy through comparative evaluation by the cutting time, heat generation and initial stability. Materials and Methods : Three design factors were considered for the purpose of drill design optimization; the number of flute(2 flute, 3 flute), helix angle($15^{\circ}$, $25^{\circ}$) and drill tip shape(straight, 2-phase). Design factors were selected through comparative evaluation by temperature change, cutting time and ISQ value. Results : Heat generation and cutting time are influenced by all design factors(p<0.05). Drill tip shape was the only factors which influenced to the largest initial stability(p<0.05). Conclusion : Drills with 2 flutes, 2-phase formed drill tip, and 25 degrees of helix angle exhibit a better performance than other design.

• 한국산학기술학회논문지
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• 제14권7호
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• pp.3151-3157
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• 2013

본 연구에서는 전자부품 및 소형 플라스틱제품에서 많이 사용하는 리브(rib) 가공에 있어 기존 플렛형 2날(2F)공구와 외날형 공구(1F)의 비교실험을 통해 다음과 같은 결과를 얻었다. 직선가공의 표면거칠기 및 공구마모는 기존 플렛형의 스트레이트 구조를 갖는 공구가 좋은 결과를 보였다. 깊이 7mm 리브 가공이 기존 공구에 비해 개발공구의 표면거칠기가 약 50%정도 양호하게 나타났다. 가공시간 또한 리브 형상별 차이는 있을 수 있으나, 기존 공구에 비해 약 3배 정도 빠르게 가공할 수 있었다.