• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.344-354
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• 2015

In order to study the development of partial discharge (PD) under typical protrusion defects in gas-insulated switchgear, we applied step voltages on the defect and obtained the ${\varphi}-u$ and ${\varphi}-n$ spectrograms of ultra-high frequency (UHF) PD signals in various PD stages. Furthermore, we extracted seven kinds of features to characterize the degree of deterioration of insulation and analyzed their values, variation trends, and change rates. These characteristics were inconsistent with the development of PD. Hence, the differences of these features could describe the severity of PD. In addition, these characteristics could provide integrated characteristics regarding PD development and improve the reliability of PD severity assessment because these characteristics were extracted from different angles. To explain the variation laws of these seven kinds of parameters, we analyzed the relevant physical mechanism by considering the microphysical process of PD formation and development as well as the distortion effect generated by the space charges on the initial field. The relevant physical mechanism effectively allocated PD severity among these features for assessment, and the effectiveness and reliability of using these features to assess PD severity were proved by testing a large number of PD samples.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1163-1171
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• 2004

The variation of spark plug location have one of the effects on combustion characteristics. Several parameters of the effect on combustion characteristics are shape of combustion chamber, the spark plug position, turbulence flow and so on. This paper presents an experimental study according to variation of spark plug protrusion and PDA valve which have effects on characteristics of combustion and emission in single cylinder gasoline engine. Also, this paper emphasized that combustion stabilization was making by way of the reinforcement of the turbulent flow with the PDA valve. A feasibility and necessity of combustion pressure based cylinder spark timing control according to spark plug protrusion has been examined. So, this was obtained COV$\_$imep/ and the mass fraction burned(MFB) and the specific fuel consumption(sfc). Using the results of the test, the effects of the variable spark plug location and PDA valve can be improved fuel consumption and be available for the combustion stability.

• 대한지리학회지
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• 제35권1호
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• pp.17-38
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• 2000

The marine terraces often offer come important clues to understand the topographic development during the Quaternary and the present landforms in korea. We examined the mechanism of the marine terraces formation along the coast from Samjung-Ri(community), Guryongpo-Eup(county) to Haseo-Ri, Yangnam-Myun(county), Gyungju-Si(city). Among the various but unique factors of the given coastal environment, which should contribute to the marine terraces formation together, we focused on five possible factors for the present stydy. Geologic difference in bedrocks, protrusion degree of coastiline, topological relief of sea-bottom, fluvial characteristics on land, and pattern of the waves appeared to act cooperatibely on the terrace formation of Southeastem coast in korea, while the fluvial characteristics seemed play a significant but localized role in it. Wide distribution of middle surfaces on the coast of Samjungri-Janggilri could be due to the concentration of the high waves and the weakness of the Tertiary volcanic rocks. For the sporadic distribution of the terraces on the coast of Gupungri-Gyewonri, it seemed attributable to the erosion -susceptible weak bedrock, the coastline of inner bay, shallow sea-bottom with the gentle relief, and other fluvial characteristics with the low divides. Together with the geologic difference in bedrock, other factors including protrusion degree of coast, topological relief of sea-bottom, and the transportation loads by the stream Daejongchon are believed to act cooperatively on the mechanism of the marine terraces formation on the coast of Duwonri-Upchonri.

• 대한정형도수물리치료학회지
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• 제1권1호
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• pp.75-83
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• 1995

Traction is the treatment of choice for a small nuclear protrusion. The nucleus is soft and can be influenced by suction. Traction provides a method of improving on recumbency-the only effective treatment before traction was devised. The intention is to achieve rapid reduction by distraction the joint surfaces mechanically-a positive purpose-instead of merely avoiding the compression of the upright posture by putting the patient to bed and leaving him there. Recumbency, usually successful in the end, wastes an endless amount of the patient's time and money. Traction carries the further advantage of enabling the patient to be up and about, attending to his bussiness, during treatment. Traction brings the joint surfaces much farther apart than just lying in bed, a greater centripetal force acts on the protruded part of the nucleus. Traction has three beneficial effects; 1. Suction : a sub-atmospheric pressure induces a centripetal effect on the contents. 2. Distraction : increases the distance between the articular edges. X -rays have shown an increase in width of the joint of 2.5 mm. 3. Ligamentous tightening : the posterior longitudinal ligament tightens which then exerts centipetal force on a central protrusion.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2004년도 학술대회지
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• pp.31-36
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• 2004

In this paper, fretting wear tests were conducted in air at room temperature (RT) and in water at high temperature and high pressure (HTHP) environment to analyze the wear characteristic. As for the supporting condition between the tube and spring/dimple, the gap of 0.2 mm in air at RT and the normal force of 10 N and the slip of $50\;{\mu}\;m$ in water at HTHP were applied. Four different shapes of spring/dimple specimen (type A, B, C, D) were used. Detail eaxamination of wear scar was also performed using SEM micrographs. As a result, in the case of the spring of truncated wedge, severer wear occurs than the others. Protrusion part was found and larger in air at RT. It is thought that the difference in the wear volume and the protrusion is caused by the different wear mechanism corresponding to the different environment.

• 대한치과교정학회지
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• 제15권1호
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• pp.105-114
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• 1985

In order to obtain the basic data of the movements of the mandible for orthodontic treatment and gnathosurgery of cleft individuals, the ranges and shapes of the movements of the mandible were measured in frontal, sagittal, and horizontal view with Saphon Visi-Trainer CII, in 19 adult cleft lip and palate individuals. The subjects included 5 BCLP, 9 UCLP, and 5 CLA patients. The measurements were compared with the values of normal individuals reported by Kang 1. Frontal view. The mean values for maximal laterotrusion were almost the same as those previously reported for the normal individuals. Mandibular deviation in maximal opening was usually toward the right, while it was mainly toward the left in normal individuals. Typical shield was formed only in the CLA group. 2. Sagittal view; The mean value for maximal protrusion was not different from that of normal group and antero-posterior deviation showed a significant difference. The angle of maximal protrusion and horizontal plane was less than that of normal group. 3. Horizontal view; The mean values for maximal laterotrusion and protrusion were not different from those of the normal group. The angle of the laterotrusion and horizontal plane was larger in the left and smaller in the right.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.1018-1020
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• 2013

PCB 제작 분야에서 TCP와 COF에서는 전기적인 특성검사만으로 자동화를 이루어지고 있으며, 실제 단락 및 돌기(근사단락) 형태의 데이터 불량 등에 대해서는 노동력을 동원해 불량을 검출하고 있는 실정이다. 본 논문에서는 영상처리에 의해 국부지역패턴 분석법에 기초한 검출기법을 제안한다. 제안한 방법은 히스토그램보정, 공간위치보정 및 최대왜곡좌표를 구하는 전처리 과정을 포함하여, 지역기반의 패턴분석법이 적용된다. 모의실험을 통하여 제안한 방식은 기존의 영역기반의 검출기법에 비해 성능이 개방 및 근사개방 결함 검출에서 크게 성능을 개선할 수 있음을 보인다.

• 한국의류산업학회지
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• 제15권3호
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• pp.414-422
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• 2013

This study identifies the foot shapes of elderly men by classifying foot types according to the shapes of sole of foot and analyzing individual characteristics. The subjects were 269 elderly men over 60 years of age. Their right feet were measured indirectly with a 2D scanner. The anthropometric measuring items consisted of 38 items that were estimated on the right foot of each subject. The 2D scan data were analyzed by various statistical methods such as factor analysis, ANOVA and cluster analysis using the statistical program SPSS 19.0. A total of 8 factors were extracted through a factor analysis and these factors represent 77.83% of total variance. The 8 factors were: ball and lateral foot protrusion, ball gradient, medial foot protrusion, anterior and posterior foot length ratio, lateral ball length, heel size, toes breadth, and foot length, that explained 77.83% of the total variance. A total of 4 clusters (as their sole type) were categorized using 8 factor scores by cluster analysis. Type 1 was classified as H-type(toes width, foot width, heel width uniform and medial malleolus and lateral malleolus almost no protrusion). Type 2 was classified as V-type(foot width and toes width, wide and heel width narrow). Type 3 was classified as A-type(foot width and heel width, wide but toes width narrow, protruded inside). Type 4 was classified as D-type(protruded outside).

• Anatomy and Cell Biology
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• 제50권1호
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• pp.41-47
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• 2017

This study investigated the topographic relationships among the eyeball and four orbital margins with the aim of identifying the correlation between orbital geometry and eyeball protrusion in Koreans. Three-dimensional (3D) volume rendering of the face was performed using serial computed-tomography images of 141 Koreans, and several landmarks on the bony orbit and the cornea were directly marked on the 3D volumes. The anterior-posterior distances from the apex of the cornea to each orbital margin and between the orbital margins were measured in both eyes. The distances from the apex of the cornea to the superior, medial, inferior, and lateral orbital margins were 5.8, 5.8, 12.0, and 17.9 mm, respectively. Differences between sides were observed in all of the orbital margins, and the distances from the apex of the cornea to the superior and inferior orbital margins were significantly greater in females than in males. The anterior-posterior distance between the superior and inferior orbital margins did not differ significantly between males (6.3 mm) and females (6.2 mm). The data obtained in this study will be useful when developing practical guidelines applicable to forensic facial reconstruction and orbitofacial surgeries.

• 한국임상수의학회지
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• 제40권1호
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• pp.38-43
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• 2023

This study compared the degree of disc degeneration of intervertebral disc between normal disc and disc disease using Magnetic Resonance images of tholacolumbar and lumbar vertebrae in dogs. The sample population consisted of 72 dogs and 188 intervertebral discs. These dogs were divided into four groups according to MRI criteria: normal, disc protrusion, disc extrusion, and fibrocartilaginous embolism. The Pfirrmann classification developed by Pfirrmann for use in human medicine was used to assess the degree of disc degeneration. Statistical analysis revealed that disc diseases had a significant difference in the degree of disc degeneration compared to normal discs in the intervertebral disc. Fibrocartilaginous embolism was found to have a relatively low disc degenerative change compared to two other disc disease groups, disc protrusion and disc extrusion. Disc degeneration in the disc extrusion group was slightly higher than that in the disc protrusion group, although the difference between the two groups was not statistically significant.