• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1148-1153
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• 2003

An adequate method for the prediction of machining errors is essential to improve productivity and product quality. But it is known that there is a remarkable difference between values calculated by conventional roughness model and measured values of actual machined surfaces under high efficient cutting condition. This paper introduces the theoretical analysis of characteristic lines of cut remainder to evaluate a geometrical surface roughness accurately. In this study, analytic equations of the characteristic lines are derived from the surface generation mechanism of ball end milling considering the actual trochoidal trajectories of cutting edges. The predicted results are compared with the results of conventional roughness model.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.66-69
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• 2003

This paper presents the procedures for the evaluation of the maximum surface roughness and the shapes of the cut remainder employing the ridge method. The shapes and the heights of the cut remainder are estimated by overlapping adjacent ridges in consideration of the various machining parameters: the feedrate. the path interval. The maximum surface roughness in plane cutting modes are derived as a function of the maximum effective cutter radius, R$\_$eff,max/. and the path interval ratio, $\tau$$\_$fp/, The predicted results are compared with the values estimated by the conventional roughness model.

• 한국정밀공학회지
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• 제21권1호
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• pp.51-60
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• 2004

Ball-end milling is one of the most common manufacturing processes for the parts with sculptured surface. However, the conventional roughness model is not suitable for the evaluation of surface texture and roughness under highly efficient machining conditions. Therefore, a different approach is needed for the accurate evaluation of machined surface. In this study, a new method, named ‘Ridge method’, is proposed for the effective prediction of the geometrical roughness and the surface topology in ball-end milling. Theoretical analysis of a machined surface texture was performed considering the actual trochoidal trajectories of cutting edge. The characteristic lines of cut remainder are defined as three-types of ‘Ridges’ and their mathematical equations are derived from the surface generation mechanism of ball-end milling process. The predicted results are compared with the results of conventional method. The agreement between the results predicted by the proposed method and the values calculated by the simulation method shows that the analytic equations presented in this paper are useful for evaluating a geometrical surface roughness of ball -end milling process.

• 화약ㆍ발파
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• 제26권2호
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• pp.29-37
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• 2008

도로 및 철도 건설에서 적용되는 터널의 단면크기는 $50m^2$에서부터 $200m^2$의 중 대단면 터널이 주를 이루고 있으나, 전력구, 통신구, 광산용 터널, 용수를 위한 도수로터널 등 특수한 용도로 설계, 시공되고 있는 터널에서는 $20m^2$이하의 단면크기를 갖는 경우가 많다. 소단면 터널의 경우에는 협소한 작업공간으로 인하여 적용공법 뿐만 아니라 장비의 사용 또한 제약을 받게 되어 작업효율이 저하되고 공사기간이 늘어나게 되는 등 여러 가지 문제점을 안고 있다. 특히, 에멀젼 폭약을 사용하는 발파에서 먼저 기폭된 발파공의 충격압력에 의해 인접공의 폭약이 예비압축되어 사압현상을 일으키고 잔류약을 발생시키는 사례가 종종 발생하고 있다. 사압현상은 발파의 실패와 함께 2차적인 사고의 위험요인이 될 수 있으므로 이를 방지하기 위한 대책을 수립하여야 한다. 기존 문헌을 통하여 사압현상의 원인과 발생 가능성을 검토하였고, 사압현상이 발생한 소단면 터널현장을 대상으로 그 대책을 수립하여 적용하였다. 심발방법을 변경하여 전단의 충격압력을 견딜 수 있는 공간격을 확보하고 뇌관의 초시간격을 적절하게 배치한 발파패턴을 적용한 결과, 사암현상을 억제하고 잔류약의 발생을 감소시켜 계획 굴진장을 확보하였으며 파쇄석의 크기를 감소시키는 등 양호한 결과를 얻을 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6591-6594
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• 2015

Background: Mantle-cell lymphoma (MCL) is a unique entity of peripheral B-cell lymphoma that has a discrete morphologic, immunologic, and genetic phenotype, with more common 'classic' and less frequent 'blastoid' and 'pleomorphic' variants, associated with an aggressive clinical course. The aim of this study was to analyze proliferation (Ki-67) indices of 'classic' (c-MCL) and 'blastoid' (b-MCL) variants of a cohort of MCL and to suggest cut off values for the Ki-67 proliferation index in these two subsets. Materials and Methods: MCL cases diagnosed over $4{\frac{1}{2}}$ years at Section of Histopathology, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi were retrieved and reviewed. Ki-67 labelling was scored and analysed. Results: A total of 90 of cases of MCL were scrutinized. Mean age ${\pm}SD$ was $60.2{\pm}12.5$ years and the male to female ratio was 4:1, with 67 (75%) cases of c-MCL and 23 (25%) cases of b-MCL. Most samples were lymph node biopsies (n=68), whereas the remainder were from various extranodal sites The mean Ki-67 proliferation index was $29.5%{\pm}14.4%$ in classic variants and $64.4{\pm}15.2%$ for the blastoid variant, the difference being statistically significant (p = 0.029). Conclusions: It was concluded that differential cut-off values of Ki-67 labeling may be used in more objective way to reliably classify MCL into classic or blastoid variants by diagnostic pathologists. We propose a < 40 proliferative index to be suggestive of c-MCL and one of > 50 for the blastoid variant.

• 대한기관식도과학회:학술대회논문집
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• 대한기관식도과학회 1976년도 제10차 학술대회연제 순서 및 초록
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• pp.90.3-90
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• 1976

식도이물에 의한 식도천공은 날카로운 이물에 의한 예가 대부분이며 드물게 이물의 장기잔류에 의한다. 저자들은 8개월된 소아에서 한쪽 끝이 낚시모양으로 된 길이 20cm 굵기 3mm 정도의 철사를 연하하여 낚시 모양의 끝은 제1 식도협착부에서 식도를 천공하고 경부 좌측의 종창을 초래하였으며 철사의 반대쪽 끝은 입밖으로 나와 있는 흥미있는 식도이물 1례를 경 청하였다. 식도경검사하에서 이물제거를 시도하였으나 실패하여 경부절개하에 낚시모양의 끝은 잘라서 제거하고 나머지는 식도경검사하에 제거한 후 약 4주일동안 금식 및 tube feeding으로 치유되었다.

• Journal of Chest Surgery
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• 제10권1호
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• pp.7-17
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• 1977

The increasing frequency of post-tracheostomy stenosis parallels the increase in the incidence of tracheostomy. The development of stenosis of trachea following the operation of tracheal tumor or tracheostomy is a very serious complication. The continuing need for an adequate tracheal substitute has not been answered, despite the necessities of excision and reconstruction of the trachea to keep for effective ventilation. Experimental tracheal reconstuction, with a prosthesis of heavy Marlex mesh and pericardium, _ vas performed in twelve dogs. Five to six tracheal ring circumferential defects were created and were bridged with heavy Marlex mesh fashioned into a tube of suitable diameter. Group A: A prepared cylinder of Marlex mesh was anastomosed outside the cut ends of the trachea. Group B: The external surface of the prepared cylinder of Marlex mesh was completely covered with suitably sized patch of pericardium and overlapped all margin of the Marlex mesh by 2 to 3 mm in each direction. Group C: The internal surface of the prepared cylinder of Marlex mesh was covered with suitably sized patch of pericardium and overlapped all margin of the Marlex mesh by 2 to 3 mm in each direction. The results of this exepriment were as follow: 1. In group A and B, the graft was well bridged with new granulation and fibrous tissue, and the lumen of trachea kept good patency for effective ventilation.. The interstices of Marlex became uniformly infiltrated with young well vasculated connective tissue. Epithelization has not yet occurred at 4 weeks in each group, but there were evidences of new growing mucosa at grafted site in 6 weeks. The remainder of the prosthesis was completely covered with glistening epithelium and the underlying fibrous tissue became more matured with little inflammation. These findings were more striking in group B than group A. 2. In group C, the covered pericardium was necrotized with stenosis of the lumen of grafted site due to poor blood supply.

• 한국의상디자인학회지
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• 제10권2호
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• pp.139-147
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• 2008

This study aims to investigate and analyze sewing methods according to the shape of the inner collar among women's jeogories in order to understand such sewing techniques, which has emerged during modern Korea, and has utilized diversly for the shape of the jeogori's inner collar and as part of the inner collar. The study was conducted on relics possessed between 1900 to 1990, or 515 pieces of jeogories. Jeogories were classified into single-layered and double-layered jeogories according to the shape of their composition. Inner collar shapes of jeogories have also been categorized. It was found that single-layered jeogories comprise 49 inner collars with shapes identical to those of the outer collars. Double-layered jeogories comprise of the following three types: 43 pieces of godae close, 18 pieces in which the inner collar of the outer bodice are cut without a connecting line and the inner collar of the godae and inner bodice are suspended, and 405 pieces in which the share of the inner collar is identical to that of the outer collar. From the shapes of inner collars mentioned above, the following sewing methods have been derived: 1. To sew the inner collar of single-layered jeogories, a seaming technique had been used. 2. Among the inner collars of a double-layered jeogori, godae close was sewn with only a short part of the godae by using a lining, and then finished with overage and blind stitches. Godae close was a covenient way to attach inner collars, and also saved much time. 3. Inner collars with shapes identical to the outer collar are divided into two groups: those with outer collars cut out fellowing the cloth without seam and shifted towards the linings and used as an inner collar, and those with outer collars made of outer linings and inner collar of inner linings. To sew the collar, paste and needlework had been employed, where the methods of needlework were divided into blind stitch, overage stitch, and catch stitch. In sewing with paste, only godae was blind stitched or overage stitched, and the remainder had been painted with paste or the collar had been finished with heated soldering iron after the entire inner collar was painted with paste.

• Journal of Chest Surgery
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• 제12권4호
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• pp.324-335
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• 1979

During the period of 4 years from August 1975 to August 1979 one hundred and forty seven cases of lung cancer were seen at Paik Foundation Hospital in Seoul, Korea. Among these 147 cases, 104 patients had primary carcinoma of the lung and the remainder was metastatic carcinoma to the lung. Among these 104 primary carcinoma patients, 73 cases were proven histologically as primary carcinoma of the lung. There were three cases of alveolar cell carcinoma [Table 1 ]. This clinical observation is based on those 73 cases including three case reports of the alveolar cell carcinoma. 1. Peak incidence was observed in the 5th decade of life. Male to female ratio was 2 to 1 [Fig. 1]. 2. Pathological classifications were as follows: epidermoid carcinoma, 24 cases [32.9%]; undifferentiated carcinoma, 20 cases [27.4%]; adenocarcinoma, 15 cases [20.5%]; bronchioloalveolar carcinoma [5.5%] and positive cytology, 10 cases [13.7%] [Fig. 2]. 3. Evidence of inoperability was observed in 55 patients [75% of the 73 cases] [Table 3]. 4. Among those 73 cases, operability was evaluated in 18 patients or 25%. One patient refused operation and 17 patients [23.6%] were explored. In 11 [15%] out of 17 patients, thoracotomies were performed. Six cases were pneumonectomies and 5 cases were lobectomies or bilobectomies [Fig. 3]. 5. First case of alveolar cell carcinoma was a 46 year-old housewife complaining of cough and hemoptysis for one year. The plain chest X-ray and bronchogram showed characteristic pictures as Figures 4 and 5. A pneumonectomy was carried out. Histologically, a beautiful alveolar carcinoma consisted of the characteristic tall columnar epithelial cells, which were lining the alveolar spaces as seen in Figures 6, 7, 8, and 20. 6. In the second case of 41 year old male, predominant clinical feature was single, well defined mass in the right lower lobe [Fig. 10 and 11] on chest X-ray. Bilobectomized specimen showed fragile, soft and hard tissue containing mucoid secretions and focal yellowish necrosis with pigmentation on cut surface [Fig. 12]. Slides showed tumor cells lined up along the alveolar septa with papillary projections [Fig. 13 and 14]. 7. Third case of alveolar cell carcinoma was a 50-year-old housewife with hemoptysis. An outstanding clinical picture was a round to lobulated mass in the right upper lobe [Fig. 16]. She is living now, 2 years and 1 month post-operatively, but has arrived at terminal stage with military nodular disseminations to the contralateral lung [Fig. 19].