• 대한두경부종양학회지
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• 제31권1호
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• pp.34-38
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• 2015

Progressive transformation of germinal centers(PTGC) is a rare benign lymph node enlargement characterized by chronic lymphadenopathy and the presence of germinal centers with fused and expanded mantles within a lymph node that are 3-5 times the size of a typical reactive follicle. Although PTGC is reported in 3.5-10% of chronic lymphadenopathy, head and neck surgeons do not often experience this condition and its clinical implications. Althoug PTGC is benign disease, it could not be excluded the association with other malignant lymphoid diseases. Therefore, periodic follow up of PTGC patient could be required. We report two cases at this study ; a 16 years old man who visited out-patient clinic due to palpable mass of right cervical area, several months ago, and a 35 years old man who visited out-patient clinic for evaluating right cervical mass. Both of two patients were diagnosed with PTGC. In this study, we focus on the clinic-pathologic features of this uncommon disease along with other literature reviews.

• 한국안전학회지
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• 제15권2호
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• pp.103-110
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• 2000

This paper deal with the stability evaluation and suggestion of progressive failure slope in biotite granite area of Andong. Based on geological site investigation and field test, stability analysis of slope was performed in conjunction with limit equilibrium methods and stereographic projection. Additionally, initial design and construction procedure was critically evaluated. Series of the slope stability analysis reveals the detection of local wedge and plane failure under the current slope condition. It is additionally appeared that a certain synthetic behavior of circle and plane failure exists on the right spot where the overall failure's going in progress. In order to construct more stable slope based on the suitability for the real state of the slope circumstances, this study issues a solution to eliminate the primary factors which cause the instability, by means of the grade of weathering and RMR classification of rock mass.

• 소성∙가공
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• 제23권8호
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• pp.501-506
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• 2014

Progressive shearing with blanking dies is commonly employed to produce large quantities of tiny sheet metal electronic parts. Sheet metal pins, which are narrow and long, that are sheared with a progressive die set are often twisted. The twist in the sheet metal pins, which usually occurs in the final shearing operation, generally decreases with increasing blank holding force. The blank holding forces in all shearing operations are not the same because of different shearing positions and areas. In the current study, the optimal layout of the springs in a progressive die set to minimize the twist of the sheet metal pin is proposed. In order to find the holding force acting on the tiny narrow blanks produced with the proposed springs during the shearing process, the equivalent area method is used in the structural analysis. The shearing of the sheet-metal pin was simulated to compute the twist angle associated with the blank holding force. The constraint condition satisfying the pre-set blank holding force from the previous shearing operations was imposed. A design of experiments (DOE) was numerically implemented by analyzing the progressive die structure and by simulating the shearing process. From the meta-model created from the experimental results and by using a quadratic response surface method (PQRSM), the optimal layout of the springs was determined. The twist of sheet metal pin associated with the optimal layout of the springs found in the current study was compared with that of an existing progressive die to obtain a minimal amount of twist.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.1012-1016
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• 2002

This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in Auto-LISP on the Auto-CAD with a personal computer and is composed of four main modules, which are input and shape treatment, flat pattern layout, strip layout, and die layout modules. The system is designed by considering several factors, such as bending sequences by fuzzy set theory, complexities of blank geometry, punch profiles, and the availability of a press equipment. Strip layout drawing generated in the strip layout module is presented in 3-D graphic forms, including bending sequences and piercing processes with punch profiles divided into for external area. The die layout module carries out die design for each process obtained from the results of the strip layout. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.735-739
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• 2001

This paper describes a research work of developing computer-aided design of a product with bending and piercing for progressive working. An approach to the system for progressive working os based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theorise, experimental results and the empirical knowledge of field experts. the system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of three main modules, which are input and shape treatment, flat pattern layout and strip layout modules. Strip layout of the system is designed by using fuzzy set theory. Process planning is determinated by fuzzy value according to several rules. Strip layout drawing generated in strip layout module is presented in 3-D graphic forms, including bending sequences and piercing processes with punch profiles divided into for external area. Results obtained using the modules enable the manufacturer for progressive working of electric products to be more efficient in this field.

• 한국환경과학회지
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• 제12권2호
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• pp.195-199
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• 2003

This landscape design is a work for which we selected the square of Sejong Center for the Performing Arts as a object area, drew inhuman factors, and tried to restore them to human environment. This plan assumes that excessive urban environment results from disorder and man can keep it in order and restore it to human environment through the progressive process of speculation. In this plan, we included the least parking space and nearby roads in the object area to maximize the location feature and the symbol of cultural space, and planned that the object area may play its role of open space in the downtown. To grant the symbol of culture space, we established the progressive process of speculation and the relationship of mu, heaven and earth, and culture, geometrically diagrammatized it, combined the circular and rectangular lines derived from it, and suggested a plan. Urban environment will continue to change in the future. However, as long as it is not ensured that the change will progress upward, city would be far from human environment anyhow. Effects to display inhuman space overlooked in the downtown and restore it to human environment for citizen and location for man, should continue.

• 한국정밀공학회지
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• 제15권6호
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• pp.22-32
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• 1998

This paper describes a research work of developing a computer-aided design of irregularly shaped-sheet metal product with bending and piercing operation for progressive working. An approach to the CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of five main modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, and strip-layout module. Based on knowledge-based rules, the system is designed by considering several factors, such as radius and angle of bend, material and thickness of product, complexities of blank geometry and punch profile, and availability of press. This system is capable of unfolding a formed sheet metal part to give flat pattern and automatically account for the adjustment of bend allowances to match tooling requirements by checking dimensions and the best utilization ratio of blank-layout within bending production feasibility area which is beyond ${\pm}30^{\circ}$ degrees intersecting angle between grain flow and bending edge line and which is suitable to progressive bending operation. Also the strip-layout drawing generated by a bending and a piercing operation according to punch profiles divided into automatically for external area of irregularly shaped-sheet metal product is displayed in graphic forms.

• Journal of Ecology and Environment
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• 제29권3호
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• pp.265-275
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• 2006

대구 인접지역 삼림식생에 대한 진행천이의 메카니즘과 잠재자연식생을 추정하였다. DCA 에 의한 요인 분석에서는 해발 고도 및 습도구배에 따라 각 군락의 특성이 결정되는 것으로 나타났으며, 토양의 수분 함량과 유기물 함량 및 전질 소량은 군락이 발달함에 따라 높아지는 것으로 나타났다. 종관 연관분석에서는 2개의 종집단으로 크게 구분되었으며, 이들 두 집단의 유형을 결정하는 요인은 기온 및 토양의 수분 요인으로 판단되었다. 특히, 두 종집단은 천이의 진행에 따라 종조성이 달라지는 군락의 발달단계를 보여주는 것으로 보이며, 생활형 조성도 이를 뒷받침하였다. 입지요인 및 종조성에 따라 소나무 군락, 굴참나무군락, 상수리나무군락 및 떡갈나무군락은 졸참나무군락이나 신갈나무군락으로 각각 천이가 진행될 것으로 예측되었다. 본 조사지역의 잠재자연식생은 종조성, 토양환경 및 지형요인에 의하여 산지 중 상부의 신갈나무군락, 계곡부의 고로쇠나무-까치박달군락, 산지 중 하부는 졸참나무군락 의 3개 유형으로 구분되었다. 그리고 신갈나무군락과 고로쇠나무-까치박탈군락은 현존 식생이면서 잠재자연식생이며, 소나무군락은 현재의 종조성 및 해발 영역을 토대로 신갈나무군락과 졸참나무군락으로 각각 발달할 것으로 예측되었다.

• 한국농촌건축학회논문집
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• 제2권2호
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• pp.11-22
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• 2000

The structure and space construction of local houses and its form of shape were under the influence of the character of locality and times. Each area makes an distinctive culture by spreading the developed culture to an undeveloped area. Frequent interchange were formed between Samcheok and Bonghwa district for a long time ago. But the change of life zone by progressive traffic makes it to a strange area. Accordingly this study clarify the changed shape and form of local houses by selecting and put it on record an scattered along the road of old times.

• 한국항공우주학회지
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• 제47권4호
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• pp.256-265
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• 2019

본 논문에서는 평직물 CFRP로 제작한 직교 격자 쉘의 굽힘 하중에 의한 점진적 손상 연구를 수행하였다. 직교 격자는 복합재 바닥면과 함께 경화하여 제작하였다. 굽힘을 받는 직교 격자 쉘의 점진적 손상 해석은 Hashin-Rotem 파손 기준과 Matzenmiller-Lubliner-Taylor (MLT) 모델으로 비선형 유한요소법을 이용하여 수행하였다. 또한, 직교 격자 쉘에 대한 3점 굽힘 시험을 수행하였으며, 시험 결과와 해석 결과를 비교하였다. 변형률과 변위에 대한 시험과 해석 결과는 유사하게 나타났다. 손상 영역은 점진적 손상 해석으로 예측하였으며, 육안 검사와 초음파 비파괴 검사를 통해 측정한 결과와 비교하였다.