• 농업과학연구
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• 제43권2호
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• pp.240-248
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• 2016

Radish is a common vegetable consumed in Korea, Japan, and China. Radish Breeding has been conducted based on morphological properties, such as shape and color. Recently, physicochemical properties of radish are attracting more attention from breeders to develop cultivars for the retail market. In this study, major components of radish were determined and their relationship with textural property analyzed. Sixty-six radish cultivars were selected and divided into white head (WH) and green head (GH) according to their head color. The cutting forces of GH and WH groups were $2.17{\pm}0.34kg$ and $2.31{\pm}0.36kg$, respectively (P > 0.05). The starch contents of GH and WH were $3.75{\pm}0.39g\;per\;100g$ (dry basis) and $4.24{\pm}0.62g$, respectively. Cellulose contents in both groups were similar at 12.3-12.4 g per 100 g (dry basis). Pearson correlation coefficients between cutting force, cellulose content, and starch content ranged from -0.33-0.326 which does not demonstrate any strong correlation between these components. Therefore, no relationship was found between the cutting force and the starch content or the cellulose content for the cultivars analyzed in this study. As the first intensive study on the texture and the major components of radish, these results could provide valuable information for radish breeding if further studies on taste and nutrient components are conducted.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.373.1-373
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• 2002

Impact is the most common type of dynamic loading conditions that give rise to impulsive forces and affects the vibrational characteristics of mechanical systems. Since the impact force and response are measured indirectly through the sensors, it is difficult to predict the impact force and acceleration. In this study, contact force model based on the Hertz law is proposed in order to predict the impact force correctly. (omitted)

• 동력기계공학회지
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• 제16권3호
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• pp.64-68
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• 2012

Because the magnetic bearing supports levitating body without contact, wear, noise and vibration are very small comparing with mechanical bearings, it is very useful to high revolution machinery. In general, the magnetic attractive force function that is proportional to square of control current(x), and inversely proportional to square of an air gap(i) has been widely used. This paper proposed the new magnetic attractive force function that is proportional to cube of the control current, and inversely proportional to square of the air gap. The function was optimized to minimize the cost function that is the percentage of deviation about the change of a proportional constant(k), using the experimental data, ie, control currents and air gaps.

• Structural Engineering and Mechanics
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• 제59권6호
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• pp.973-992
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• 2016

A direct and relatively simple method for controlling nodal displacements and/or internal bar forces has been developed for prestressable structural assemblies including complex elements ("macro-elements", e.g., the pantographic element), involving Matrix Condensation, in which structural matrices being built up from matrices of elementary elements. The method is aimed at static shape control of geometrically sensitive structures. The paper discusses identification of the most effective bars for actuation, without incurring violation in bar forces, and also with objective of minimal number of actuators or minimum actuation. The advantages of the method is that the changes for both force and displacement regimes are within a single formulation. The method can also be used for adjustment of bar forces to either reduce instances of high forces or increase low forces (e.g., in a cable nearing slack).

• 시큐리티연구
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• 제24호
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• pp.125-146
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• 2010

이번 11월에 서울에서 개최되는 G20 정상회의는 전 세계적 경제위기 도중에 치러진다는 점에서 매우 중요한 의미를 가지는 것으로 평가되고 있다. 그러나 이전의 G20 정상회의와 마찬가지로 서울 정상회의시에도 대규모 반세계화 집회시위가 있을 것으로 예상된다. 그러므로 이번 정상회의의 경호경비를 책임지고 있는 우리 경찰은 회의에 참가하는 각국 정상의 안전을 보장하고 원활한 회의진행을 위하여 이러한 반세계화 집회시위에 효과적으로 대처해야 할 것이다. 본 연구에서는 2009년 G20 런던 정상회의 도중 경찰의 물리력에 의해 사망한 이안 톰린슨(Ian Tomlinson) 사건을 문헌조사를 통해 사례분석하고, 이를 바탕으로 G20 서울 정상회의에 적용 가능한 집회시위 경비방안을 제시하였다. 사례분석결과, G20 런던 정상회의시 영국경찰은 집회시위 대응과 관련하여 물리력 사용에 대한 기준 및 훈련부족, 언론에 대한 미숙한 대처, 시위대와의 의사소통 부족, 케틀링(Kettling) 기법의 남용, 경찰관 인식표 미착용 등의 문제점을 가지고 있었던 것으로 밝혀졌다. 본 연구에서는 이러한 분석결과에 근거하여 평화시위의 유도, 물리력 사용의 기준 확립과 훈련의 강화, 언론 및 시위대와의 의사소통 증진, 경찰관의 책임성 향상 등을 G20 서울 정상회의시의 집회시위 경비방안으로 제시하였다.

• 한국초전도ㆍ저온공학회논문지
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• 제11권2호
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• pp.15-19
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• 2009

Bulk $YBa_2Cu_3O_{7-{\delta}}$ (YBCO) superconductor was manufactured with the top-seeded melt grown method. The 9, 16, and 25 holes, as small as 0.7mm in diameter, parallel to the c-axis were mechanically drilled. Magnetic flux mapping and levitation force were measured and compared to estimate the influence of multiple holes on the magnetic properties of YBCO superconductor at 77K. According to the measurements, the maximum magnetic flux density obtained from the plain sample was 2.48kG, while the maximum magnetic flux density of the sample with 25 holes was low as around 2.29kG. The levitation force measured on the sample with 9 holes increased from 91N to 105N. The levitation force measured on the samples with 9 holes is relatively higher than the plain sample without any holes. In this case, increase of the levitation force in the perforated samples could be explained by enhancement of the cooling efficiency more effectively. We investigated that the magnetic properties of YBCO superconductor were strongly influenced by the artificial holes.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.1051-1052
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• 2013

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.1089-1090
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• 2011

• 대한치과보철학회지
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• 제38권2호
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• pp.214-225
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• 2000

The purpose of this study was to investigate the effects of investing conditions on the marginal discrepancy of conical telescope outer crown with Co-Cr-Ti alloy(Dentitan) and to compare the marginal discrepancy and the retention force of outer crowns using different pattern materials(plastic foil, casting wax, pattern resin). To evaluate the effects of investing conditions on the marginal discrepancy, patterns with plastic foil were invested under three different liquid/powder ratio conditions using phosphate bonded investment(Univest-nonprecious): standard, 10% decreased and 10% increased. At each liquid/powder ratio condition, metal ring was lined with single or double layers of ceramic ring liner. The marginal discrepancy of outer crown at different investing conditions was measured by ${\times}100$ compact measuring microscope(STM5, Olympus, Japan). For measurement of the marginal discrepancy and the retention force of outer crown using different pattern materials, the investing condition of 10% decreased liquid/powder ratio and double layers of ring liner was selected because this investing condition resulted in the best fit of outer crown. Marginal discrepancy was measured in the same way above and retention force on universal testing machine. Under the conditions of this study, the following conclusions were drawn: 1. The thickness of ring liner had more influence on the marginal discrepancy of outer crown than the liquid/powder ratio, and the acceptable marginal fitness could not be expected at the investing condition directed by investment manufacturer 2. There were no differences in the marginal discrepancy of outer crown among three different pattern materials(P>0.05). 3. Casting wax showed the greatest retention force(1640g) of outer crown, followed by pattern resin(1110g), plastic foil(820g). However, there was no significant difference between plastic foil and pattern resin(P>0.05). 4. Plastic foil showed the least variation in marginal discrepancy and retention force.

• 한국식품저장유통학회지
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• 제13권5호
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• pp.538-542
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• 2006

가온재배한 한라봉감귤의 분포도, 물리화학적 품질특성을 검토하였다. 한라봉은 과중 $250{\sim}400g$이 90%를 차지하는데 비하여, 한라봉 변이종인 M16A 품종에서는 나무나이가 어리고 열매솎기의 영향으로 결실 정도가 낮아 $400{\sim}450g$을 중심으로 한 큰 과일의 분포가 상대적으로 많았다. M16A의 과일크기가 한라봉에 비하여 컸지만 껍질두께는 오히려 3.29mm로 한라봉의 3.51mm에 비해 얇고 과육과 밀착되어 있었다. 중간 위치에 달려있는 한라봉의 경도가 832.8 g-force에 비하여 M16A가 994.7 g-force로 높아 단단한 형태를 보였으며, 과육율도 3% 정도 높았다. 당도와 산 함량은 한라봉이 $12.20{\sim}12.98^{\circ}Brix$와 $1.08{\sim}1.14%$, 그리고 M16A가 $1.48{\sim}12.63 ^{\circ}Brix$와 $0.92{\sim}1.00%$이었다. 비타민 C 함량은 한라봉에서 $71.30{\sim}78.77mg/100g$, 그리고 M16A에서 $64.40{\sim}68.01mg/100g$이었다. 과육의 위치에 따라 성분 함량이 차이가 있었으며, 밑 부분으로 갈수록 당도가 높았다. 상부에 달려있는 과일은 크기가 컸으며 껍질이 두껍고 과육율이 낮았으며 경도도 높았다. 그리고 당도와 산 함량이 모두 높았으며, 이는 일조량이 상대적으로 많은 결과로 보인다.