• Korean Journal of Agricultural Science
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• v.43 no.2
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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.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11a
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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)

• Journal of Power System Engineering
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• v.16 no.3
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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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• v.59 no.6
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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).

• Korean Security Journal
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• no.24
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• pp.125-146
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• 2010

The G20 summit is the premier forum for international economic cooperation and it will be held in Seoul in November 2010. However, protests are expected during the Seoul summit, as a part of the deepening global war against capitalism. The Korean Police need to deal with these protests effectively in order to provide security to the participating leaders and make the meeting run on wheel as planned. The current study attempts to analyze the death of Ian Tomlinson who died in the context of a heavily policed protest during 2009 G20 London summit. There are number of unique features regarding this incident, such as the public scrutiny of police conduct through video footage, the police use of excessive force, and the process to hold the police to account for misconduct. This incident caused serious damages to the public's faith in the British police. Based on the analysis, this study found that during the G20 London summit British police had the problems such as the lack of the clear standards on the use of force, improper training in the use of force, poor communications with the media and protesters, inappropriate use of the close containment tactic, and the failure to display police identification. Therefore, this study suggests the inducement of peaceful protests, the adoption of a set of standards on the use of force, public order training that is more directed and more relevant to the public order challenges facing the Korean police, improvement of the communication with the media and protesters, enhancement of individual officer's accountability as public order policing strategies for G20 Seoul summit meeting. However, the most fundamental principle is that Korean police must place a high value on tolerance and winning the consent of the public.

• Progress in Superconductivity and Cryogenics
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• v.11 no.2
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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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.1051-1052
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1089-1090
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• 2011

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.2
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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.

• Food Science and Preservation
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• v.13 no.5
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• pp.538-542
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• 2006

Physicochemical properties and positional distribution of Hallabong Tangor (Citrus Kiyomi ${\times}$ ponkan) cultivated in heated greenhouse were investigated. About 90% of Hallabong produce fruit within the range of $250{\sim}400g$ fruit weight on a tree, larger fruits were mainly consisted of $400{\sim}450g$ in M16A, a variant species of Hallabong, due to younger tree and fruit thinning. Nevertheless fruit sizes of M16A were larger than Hallabong, and peel thickness of M16A (3.29 mm) was thinner than that of Hallabong (3.51 mm). Hardness of m6h was 994.69g-force, compared to 832.8 g-force of Hallabong on the average. Soluble solids and acid content of Hallabong were $12.20{\sim}12.98^{\circ}Brix$ and $1.08{\sim}1.14%$, while those of M16A were $1.48{\sim}12.63^{\circ}Brix$ and $0.92{\sim}1.00%$, respectively. Vitamin C content of Hallabong was $71.30{\sim}78.77 mg/100 g$, compared to $64.40{\sim}68.01mg/100g$ in M16A. Soluble solid in the part of stem was lower than that of end part among the same segment. Fruit size in the upper part of the tree was larger, the peel was thicket and flesh ratio was lower than the middle or lower part. However, soluble solids and acid content were high, due to cumulative sunshine during cultivation.