• Journal of the Korean Society of Safety
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• v.30 no.5
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• pp.108-113
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• 2015

Plastic injection moulding machine is widely used for many industrial field. It is classified into mandatory safety certification machinery in Industrial Safety and Health Act because of its high hazard. In order to prevent industrial accidents by plastic injection moulding machine, it is necessary for designer to identify hazardous factors and assess the failure modes to mitigate them. This study tabulates the failure modes of main parts of plastic injection moulding machine and how their failure has affect on the machine being considered. Failure Mode & Effect Analysis(FMEA) method has been used to assess the hazard on plastic injection moulding machine. Risk and risk priority number(RPN) has been calculated in order to estimate the hazard of failures using severity, probability and detection. Accidents caused by plastic injection moulding machine is compared with the RPN which was estimated by main regions such as injection unit, clamping unit, hydraulic and system units to find out the most dangerous region. As the results, the order of RPN is injection unit, clamping unit, hydraulic unit and system units. Barrel is the most dangerous part in the plastic injection moulding machine.

• Nuclear Engineering and Technology
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• v.30 no.1
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• pp.8-16
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• 1998

In this work a method to detect the vibrational peak and to decide the vibrational mode of detected peak for core internal vibration monitoring system which is particularly concerned on the core support barrel (CSB) and fuel assemblies is developed. Flow induced vibration and aging process in the reactor internals cause unsoundness of the internal structure. In order to monitor the vibrational status of core internal, signals from the ex-core neutron detectors are transformed into frequency domain. By analyzing transformed frequency domain signal, an analyst can acquire the information on the vibrational characteristics of the structures, i.e., vibration frequencies of each component, vibrational level, modes of vibration, and the causes of the abnormal vibration, if any. This study is focused on the development of the automated monitoring system. Several methods are surveyed to define the peaks in power spectrum and fuzzy theory is used to automatic detection of the vibrational peaks. Fuzzy algorithm is adopted to define the modes of vibration using the peak values from fuzzy peak recognition, phase spectrum, and coherence spectrum.

• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.854-858
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• 2008

최근 도시 및 단지 개발시 자연적인 물순환체계 구축에 대한 관심과 수요가 증가하고 있는 추세이다. 서울시를 비롯한 각 지자체에서도 빗물관리시설 적용과 관련된 조례를 제시하고 있으며, 건교부나 환경부에서도 수자원의 확보와 복원을 위한 빗물관련 법규 제정의 움직임을 보이고 있다. 또한 일부 지자체들은 도시 및 단지 개발시 빗물관리시설의 적용을 전제로 사업승인을 하는 등 수자원확보와 수순환복원을 위해 빗물관리에 대한 관심이 높아지고 있다. 특히 최근 문제시되는 물부족 현상에 대비해 대체수자원으로써 빗물의 저류와 침투를 통한 직 간접적인 활용은 수자원 확보에 있어 하나의 대안이 될 수 있다. 이에 본 연구에서는 공동주택단지를 대상으로 하여 빗물관리시설중 침투정과 침투트렌치 적용에 따른 유출저감효과를 분석하였다. 본 연구에서는 대상지점으로 표준이 될 수 있는 공동주택단지를 선정하고, 대상지점 내 적용이 가능한 곳에 기존 집수정과 우수관을 대신하여 침투정과 침투 트렌치를 가상으로 적용하였다. 침투정과 침투트렌치는 표준의 것을 적용하는 것으로 하고, '빗물 저류침투기술협회(일(日))'의 시설별 설계침투량 계산을 통해 침투정과 침투트렌치 적용에 따른 대상지점에 우수유출량을 합리식으로 계산하였다. 그리고 대상지점의 개발전 유출량과 개발후 유출량(집수정, 우수관적용), 개발후 유출량(침투정, 침투트렌치적용)의 비교를 통해 빗물관리시설의 적용에 따른 유출저감효과를 분석하였다.

• The International Journal of Costume Culture
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• v.4 no.3
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• pp.229-240
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• 2001

The purpose of the present study was to analyze the acceptance level of forecasted information of casual wear in tate 1990s in Korea and the way of utilizing fashion trends information by casual wear industries. The Present study was implemented by content analysis and descriptive survey using questionnaire and interview. Trends information in fashion journals published by fashion institute and articles in daily newspapers were analyzed in terms of fashion image, color, fabric, and silhouette. The data collected from questionnaire and interview with 113 fashion specialists were analyzed through frequency, percentage. The results indicated that among the forecasted information regarding fashion image, romantic and feminine images showed a high level of acceptance to national brand women's casual wear in the late 1990s, while mannish image showed a low level of acceptance. For men's casual wear in the same time period, androgynous trends appeared most frequently, not only in forecasted information, but also in actual trend. it was forecasted that yellow, white, and gray would be in trend and those colors appeared frequently in actual trend. On the other hand pastel tone appeared much more frequently than forecasted. Natural, thin - transparent (S/S) and stretch fabrics (F/W) were in actual trend as it was forecasted. Fit and Pare (woman), and long and slim (man) silhouettes were in actual trend as if was forecasted, but barrel silhouette appeared only in forecasted information. Most of the information forecasting fashion trends for next season were applied to the product planning of the season, right after the information comes out.

• Preventive Nutrition and Food Science
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• v.11 no.1
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• pp.61-66
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• 2006

The objective of this study was to compare the color and microstructure of powder, redness, brownness, and antioxidative activity in extruded ginseng, white ginseng and red ginseng extracts. The colors of extruded dry ginseng powder (moisture content 30%, barrel temperature $110^{\circ}C$, and screw speed 200 rpm) were similar to those of red ginseng. Intact cell wall structure was examined in dried root ginseng at $70^{\circ}C$ (A), white ginseng with skin (D), white ginseng without skin (E), and red ginseng (F) under a scanning electron microscope. The cell wall was not detected in samples B and C (dry ginsengs extruded with 25% and 30% moisture contents, respectively). Intact starch granules were detected in samples A, D, and E under a scanning electron microscope. Melted starch granules were detected in samples B, C, and F. Colors (L, a, b) of 50% EtOH extracts were similar in samples C and F. Browniness and redness of extracts were high in extruded dry ginseng and red ginseng extracts. Extruded dry ginseng (B) showed higher electron donation ability and phenolic content than the other samples.

• Journal of the Korea Institute of Military Science and Technology
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• v.12 no.3
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• pp.259-265
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• 2009

In the traditional percussion locks of small arms, a firing pin is struck by a hammer rotating on a single center of rotation, which makes the percussion mechanism simple and reliable. In order to strike the firing pin by the hammer, however, the firing pin should be located within the radius of rotation of the hammer. As the distance between the striking point of the firing pin and the center of rotation of the hammer becomes longer, the radius of rotation of the hammer should also be increased, which results in the increase of the volume and weight of the small arms because the hammer needs the more space for its operation inside of the small arms. In this paper, a link type percussion lock was newly proposed in order to overcome the limitation of designing small arms when using traditional percussion locks, as mentioned above. The link type percussion lock was modeled by using multi-body dynamics software and designed to satisfy the requirements such as striking force level of the hammer exerting on the firing pin enough to detonate the percussion cap of ammunitions and the safety on the accidental drop. It was applied to the newly developed dual-barrel weapon system, in which the weight and overall length are important design factors, and verified by durability test and drop test on the ground.

• Proceedings of the Korean Geotechical Society Conference
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• 2005.03a
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• pp.308-319
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• 2005

Piezo-ceramics are special materials which transform energy between mechanical and electrical forms. Bender-elements are composite materials consisting of thin piezo-ceramics and elastic shims, and are widely used as actuators and transducers in the field of electronics, robotics, autos and mechatronics utilizing the effectiveness of energy transformation capability. In geotechnical engineering, commercial bender-elements are used in laboratory as source and receiver in the measurements of soil stiffness. The elements were built by using various metal shims sandwiched between piezo-ceramics and coating over the composite in the research. A pair of elements were buried in a concrete block and used as source and receiver to measure the stiffness of the concrete. The test results were verified by comparing with the resonant column testing results. In a preliminary stage of the development of an in-situ seismic testing equipment using bender-elements for soft clay materials, shear waves were generated and measured by burying the elements in the barrel of kaolinite and water mixture. The measured shear wave signals were so distinct for the first-arrival pick that applicability of the elements in the field measurements is very promising.

• Journal of computational fluids engineering
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• v.6 no.3
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• pp.32-40
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• 2001

Viscous solutions of supersonic jet impinging on a flat plate normal to the flow are simulated using three-dimensional Navier-Stokes solver. The jet impinging flow structure exhibits such complex nature as shock shell, plate shock and Mach disk depending on the flow parameters. Among others, the dominant parameters are the ratio of the nozzle exit pressure to the ambient pressure and the distance between the nozzle exit plane and the impinging plane. In the present study, the nozzle contour and the pressure ratio are held fixed, while the jet impinging distance is varied to illuminate the characteristics of the jet plume with the distance. As the plate is placed close to the nozzle at 3D high, the computed wall pressure at or near the jet center oscillates with large amplitude with respect to the mean value. Here D is the nozzle exit diameter. The amplitude of wall pressure fluctuations subsides as the distance increases, but the maximum mean pressure level at the plate is achieved when the distance is about 4D high. The frequency of the wall pressure is estimated at 6.0 kHz, 9.3 kHz, and 10.0 kHz as the impinging distance varies from 3D, 4D, to 6D, respectively.

• Journal of the Korean Society of Visualization
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• v.15 no.1
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• pp.53-63
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• 2017

Sonic and supersonic jets include many complicated flow physics associated with shock waves, shear layers, vortices as well as strong interactions among them, and have a variety of engineering applications. Much has been learned from the previous researches on the sonic and supersonic jets but quantitative assessment of these jets is still uneasy due to the high velocity of flow, compressibility effects, and sometimes flow unsteadiness. In the present study, the sonic jets issuing from a convergent nozzle were measured by PIV and Schlieren optical techniques. Particle Image Velocimetry (PIV) with Olive oil particles of $1{\mu}m$ was employed to obtain the velocity field of the jets, and the black-white and color Schlieren images were obtained using Xe ramp. A color filter of Blue-Green-Red has been designed for the color Schlieren and obtained from an Ink jet printer. In experiments, two types of sonic nozzles were used at different operating pressure ratios(NPR). The obtained images clearly showed the major features of the jets such as Mach disk, barrel shock waves, jet boundaries, etc.

• Journal of Yeungnam Medical Science
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• v.10 no.2
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• pp.493-505
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• 1993

The congenital cutis aplasia mainly occurs in head, sometimes involving the skull and dura mater. It's cause and the rate of falling ill are not known yet, it is the disease that rate of death is high by the infection, such as, the injured vascular hemorrhange of meningitis. Craniosynostosis is the disease the appears the skull as well as the facial deformity with growing, has from the developmental difficiency, visual distibance, motor disturbance, convulsion to the neurologic impairment of mental retardation, and accompanies the each characteristic deformity following the suture fused. Satisfactory results was achieved by local flap surgery and conservative treatment on the infant, diagnosed as the congenital cutis aplasia, case 1 Also successful treatment experiences of craniosynostosis(oxycephaly, brachycephaly, trigonocephaly, cloverleaf deformity) through the frontal bone advancement and the barrel stave asteotomy, were reviewed & pursues and investigates the intracranial volume of before and after of surgery, and then reports with the literature investigation.