• 한국유체기계학회 논문집
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• 제18권3호
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• pp.46-52
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• 2015

Pump-turbine system is widely used by the hydropower industry for stabilizing the electrical grid in the vast growing economy of most developed countries. This study only investigates the Fluid-structure Interaction (FSI) analysis of the pump-turbine system at various operating conditions. The FSI analysis can show how reliable each component of the system is by providing the engineer with a better understanding of high stress and deformation points, which could reduce the lifespan of the pump-turbine. Pump-turbine components are categorized in two parts, pressurized static parts and movable stressed parts. The fixed parts include the spiral casing, top and bottom cover, stay vane and draft tube. The movable parts include guide vanes and impeller blades. Fine hexahedral numerical grids were used for CFD calculation and fine tetrahedral grids were used for structural analysis with imported load solution mapping greater than 90 %. The maximum equivalent stress are much smaller than the material yield stress, and the maximum equivalent stress showed an increasing tendency with the varying of operating conditions from partial to excessive at both modes. In addition, the total deformation of all the operating conditions showed a small magnitude, which have quite small influence on the structural stability. It can be conjectured that this system can be safely implemented.

• 한국산학기술학회논문지
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• 제18권4호
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• pp.334-340
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• 2017

신뢰도는 열차, 비행기, 여객선과 같이 시스템에 한번 고장이 발생한 경우 치명적인 결과로 이어져 시스템에서 중요한 설계 요인으로 고려되어진다. 상당히 높은 신뢰도를 요구하는 시스템에서 시스템의 신뢰도를 향상시키는 방법에는 다양하게 있지만, 부품의 중복은 시스템 신뢰도를 향상시키기 위한 효율적인 방법으로 알려져 있다. 신뢰도를 높이기 위해 부품을 중복하는 경우에는 어떤 부품을 몇 개를 중복해야 하는지를 시스템 신뢰도 측면과 비용, 기타 설계자원 측면에서 고려하여야 한다. 본 연구에서는 직렬 구조를 가지는 다계층 시스템에 대한 중복할당의 방법을 다룬다. 다계층시스템에 대한 정의를 설명하고, 제약된 설계비용에서 시스템 신뢰도를 최대화하기 위한 중복 부품의 선정과 중복수량을 최적화하는 방법을 다룬다. 특히, 다계층 시스템에서 경로집합 중에 단 하나의 품목만 중복이 가능한 경우에 대해서 다루며, 유효한 해를 찾기 위한 방법을 제시한다. 최적화를 위해 뻐꾸기 탐색 알고리즘을 적용한다. 뻐꾸기 탐색 알고리즘에서는 다계층시스템의 중복할당 최적화를 위한 탐색절차, 이웃해의 탐색 방법, 해의 표현 등을 제시한다. 수치예제를 통해 기존에 유전알고리즘과 뻐꾸기 탐색 알고리즘의 성능을 비교한다.

• International Journal of Precision Engineering and Manufacturing
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• 제6권2호
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• pp.12-18
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• 2005

A geometric compensation of thin-walled molded parts in reverse engineering is presented. Researches in reverse engineering have focused on the fitting of points to curves and surfaces. However, the reconstructed model is not the geometric model because the molded parts have some dimensional errors in measurements and deformation during molding. Geometric information can give an improved accuracy in reverse engineering. Thus, measurement data must be compensated with geometric information to reconstruct the mathematical model. The functional and geometric concepts of the part can be derived from geometric information. LSM (Least square method) is adopted to determine the geometric information. Also, an example of geometric compensation is given to improve the accuracy of geometric model and to inspect the reconstructed model.

• 품질경영학회지
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• 제18권1호
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• pp.96-115
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• 1990

This study suggest a plan for a small and medium auto parts enterprises in Ulsan Industrial Complex to do cooperation activity for management rationalization. To derive the plan, it is considered that characteristics of auto parts industry, existing status of cooperation activity, and faced problems of the small and medium enterprises in Ulsan area. Suggested plan may be well used for basic information of auto parts company's cooperation, and may contribute to expand cooperation activity.

• 한국정밀공학회지
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• 제18권5호
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• pp.177-185
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• 2001

This paper describes a machine-vision-based prototype system for automatically feeding engine-mount parts to a swaging machine which assembles engine mounts. The system developed consists of a robot, a feeding device with two cylinders and two photo sensors, and a machine vision system. The machine vision system recognizes the type of different parts being fed from the feeding device and estimates the angular difference between the inner-hole center of the part and the point predetermined for assembling. The robot then picks up each part and rotated it through the estimated angle such that the parts are well assembled together as specified. An algorithm has been developed to recognize different part types and estimate the angular difference. The test results obtained for a set of real specimens indicate that the algorithm performs well enough to be applied to prototype system.

• 한국의류산업학회지
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• 제6권1호
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• pp.109-113
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• 2004

The present study attempted to consider the effects of cutting lines in the knee parts of slacks on the clothing pressure and comfort. The study compared and analyzed the pressure imposed to the body in a stooping position and the consequent sensations felt by the wearer according to the slack shapes. The conclusion was drawn as follows: The pressure imposed by the slacks to the body is greater on the two points slightly upper and lower from the knee point than on the knee point itself, regardless of the slack shapes. Clothing pressure was lower in the slacks with 10 cm-wide and 14 cm-wide cutting lines in the knee parts than those with 18 cm-wide cutting lines. Subjective sensations felt in the knee parts were analyzed according to slacks shapes. As a result, it was found that slacks without cutting lines on the knee parts or with sewing lines far from the knee points were more comfortable. In slacks construction, the use of cutting lines in the knee parts can decrease pressure imposed to the knee area or improve the comfort of the slacks. When designing slacks, however, overall appearance should be considered and the weakness of cutting line that makes legs look shorter should also be complemented.

• 한국약용작물학회지
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• 제18권6호
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• pp.373-378
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• 2010

In order to obtain basic data for utilization of the aerial parts of Cnidium officinale Makino (APCO), the antioxidant properties of the aerial parts and rhizomes of C. officinale were measured using DPPH and ABTS radicals, and nitrite scavenging assays. The ethyl acetate (EA) fraction prepared from the aerial parts of APCO showed the strongest antioxidant activities, and contained high level of total phenolic compounds (325.81 mgTE/g) and flavonoids (259.16 mgRE/g). The concentrations for 50% reductions ($RC_{50}$) values of the DPPH and ABTS radicals, and nitrite by the EA fraction of APCO were $11.27\;{\mu}g/m{\ell}$, $14.34\;{\mu}g/m{\ell}$, and $10.26\;{\mu}g/m{\ell}$, respectively. APCO exhibited approximately 3-9 times higher antioxidant activity than rhizomes of C. officinale. The antioxidant capacities of APCO were positively correlated with its total phenolic contents. Therefore, it was concluded that the aerial parts of C. officinale can be a useful and cost-effective source of natural antioxidant for food or cosmetics.

• Fisheries and Aquatic Sciences
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• 제8권4호
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• pp.189-194
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• 2005

Protein, lipid classes, and fatty acid composition, including n-3 highly unsaturated fatty acids (HUFAs), were analyzed in the soft parts, which we differentiated as the adductor muscles and 'other portions,' from the cultured pearl oyster after the pearl was harvested and before the nucleus was grafted to evaluate the nutritional qualities of the soft parts. Total lipid content was higher in the other portions of the soft parts ($1.25-1.26\%$) than in the adductor muscles ($0.58­0.65\%$) in both pearl oyster samples, whereas protein content was higher in the latter ($15.5­18.7\%$) than in the former ($11.2-13.9\%$; P<0.05). The percentage of total lipids (TLs) consisting of phospholipids (PLs) was higher in the adductor muscles ($60.4-68.3\%$) than in the other portions ($40.6-47.0\%$), but the percentage of nonpolar lipids (NLs) was higher in the other portions of the soft parts. The prominent lipid classes were free sterol (FS) and triglyceride (TG) in the NLs and phosphatidylcholine and phosphatidylethanolamine in the PLs. The adductor muscles contained high levels of FS and all PL classes, while the other portions contained high levels of all NL classes, especially TG (but not FS; P<0.05). The prominent fatty acids were 22:6n-3 ($17.2-24.9\%$), 16:0 ($8.35-15.8\%$), 20:5n-3 ($7.95-14.9\%$), 18:0 dimethyl acetal (DMA, $4.79-13.5\%$), 18:0 ($4.50-6.16\%$), and 20:4n-6 ($4.36-5.43\%$). The percentages of 22:6n-3, 20:4n-6, and 18:0 DMA were higher in the adductor muscles than in the other portions of both pearl oyster samples, while those of 20:5n-3 and 16:0 were higher in the other portions (P<0.05). The levels of these food components were similar to those of other bivalves or were higher, especially the protein content, indicating that the soft parts of pearl oysters, which are currently wasted, have food value.

• 대한물리치료과학회지
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• 제7권2호
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• pp.615-628
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• 2000

This report is to study on the progress on which foot arch and planta has been changed according to body type based on 4 tilting of scapular & ilium. This study has been carried out to help contribute to some basic information like these. One was to find out how to assess and analysize the deformity of feet and ankle joint which may have the most impact on ideal alignment of anatomical posture. The other was to figure out how to diagnose and treat the deformity to get to the restoration. The results of this study is as followings; 1. The findings which had been made from 22 persons(50%) having left scapular and ilium forward tilt are as follows. 1) On the longitudinal length of the planta left parts of 18 persons(82%) are longer than the right one. On the transversel length of the planta right parts of 17 persons(77%) are longer than the left one. 2) On the size of medial longitudinal arch the left parts of 20 persons(91%) are more wider than the right one. 3) On the sign of supinated foot, the left parts of 18 persons(82%) are more common than the right one. 4) On the thickness of big toe, the left parts of 14 persons(64%) are thicker than the right one. 2. The findings which had been made from 15 persons(34%) having right scapular and ilium forward tilt are as follows. 1) On the longitudinal length of the planta right parts of 11 persons(73%) are longer than the left one. On the transversel length of the planta left parts of 13 persons(87%) are longer than the right one. 2) On the size of medial longitudinal arch the right parts of 13 persons(87%) are more wider than the left one. 3) On the sign of supinated foot, the right parts of 12 persons(80%) are more common than the left one. 4) On the thickness of big toe, the right parts of 7 persons(47%) are thicker than the left one. 3. The findings which had been made from 3 persons(7%) having left scapular and right ilium forward tilt are as follows. 1) On the longitudinal length of the planta right parts of 2 persons(67%) are longer than the left one. On the transversel length of the planta left parts of 2 persons(67%) are longer than the right one. 2) On the size of medial longitudinal arch the right parts of 3 persons(100%) are more wider than the left one. 3) On the sign of supinated foot, the right parts of 2 persons(67%) are more common than the left one. 4) On the thickness of big toe, the left parts of 2 persons(67%) are thicker than the right one. 4. The findings which had been made from 4 persons(9%) having right scapular and left ilium forward tilt are as follows. 1) On the longitudinal length of the planta left parts of 3 persons(75%) are longer than the right one. On the transversel length of the planta right parts of 2 persons(50%) are longer than the left one. 2) On the size of medial longitudinal arch the left parts of 3 persons(75%) are more wider than the right one. 3) On the sign of supinated foot, the left parts of 3 persons(75%) are more common than the right one. 4) On the thickness of big toe, the left parts of 3 persons(75%) are thicker than the right one.

• 한국식품영양과학회:학술대회논문집
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• 한국식품영양과학회 2004년도 Annual Meeting and International Symposium
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• pp.224-231
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• 2004

Vitamin U levels in 26 kinds of food plants are well known to healthy vegetables in Asian or Western countries were determined. Spinach showed the highest level of 452.04 mg/kg and in order Pack-choi (343.18 mg/kg) > Kale (234.18 mg/kg) > Somssukbujaengi (197.66 mg/kg) > leaf mustard (196.21 mg/kg) > aralia bud (192.50 mg/kg)> broccoli (189.03 mg/kg) >Asparagus (187.35 mg/kg). Among Korean wild medicinal plants, Sumssukbujaengi showed the highest value followed by Sanmanul (a kind of wild garlic) level of 143.46 mg/kg. For Chinese cabbages and cabbages, vitamin U showed different levels according to the parts of plant such as core, middle, outward leaves. In both samples, middle parts of leaves including midribs contained the highest level of vitamin U. The level of vitamin U was dependent on the part of the plant sample and cultivars. Leaf parts of turnip and white radish showed higher value of 84.82 mg/kg and 124.62 mg/kg than those of roots which were in order of middle (112.39 mg/kg), top (84.84 mg/kg) and bottom (84.61 mg/kg) portions in the white radish. In the analysis of amino acids, we didn't find either distinctive relationship between methionine and vitamin U synthesis or significant connection various free amino acids and vitamin U level in food plants.