• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.263-266
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• 1998

Several constraints in machine duplication cost, machining capability, cell space capacity, intercell moves and exceptional elements(EEs) are main problems that prevent achieving the goal of ideal Cellular Manufacturin System (CMS) environment. Minimizing intercell part traffics and EEs are the main objective of the cell formation problem as it's a critical point that improving production efficiency. Because the intercell moves could be changed according to the sequence of operation, it should be considered in assigning parts and machines to machine cells. This paper presents a method that eliminates EEs under the constraints of machine duplication cost and cell space capacity attaining two goals of minimizing machine duplications and minimizing intercell moves simultaneously. Developing an algorithm that calculates the machine duplications by cell-machine incidence matrix and part-machine incidence matrix, and calculates the exact intercell moves considering the sequence of operation. Based on the number of machine duplications and exact intercell moves, the goal programming model which satisfying minimum machine duplications and minimum intercell moves is developed. A linear programming model is suggested that could calculates more effectively without damaging optimal solution. A numerical example is provided to illustrate these methods.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.465-471
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• 2000

The flow characteristics around an elliptic cylinder with axis ratio of AR=2 located near a flat plate were investigated experimentally to study the interaction between the cylinder wake and the turbulent boundary layer. The pressure distributions on the cylinder surface and on the flat plate were measured with varying the angle of attack of the cylinder. In addition, the velocity profiles of wake behind the cylinder were measured using a hot-wire anemometry As the angle of attack increases, the location of peak pressure on the windward and leeward surfaces of the cylinder moves toward the rear and front of the cylinder, respectively. At positive angles of attack, the position of the minimum pressure on the flat plate surface is moved downstream, but it is moved upstream at negative angles of attack. With increasing the angle of attack, the vortex shedding frequency is gradually decreased and the critical angel of attack exists in terms of the gap ratio. By installing the elliptic cylinder at negative angle of attack, the turbulent boundary layer over the flat plate is disturbed more than that at positive incidence. This may be attributed to the shift of separation point on the lower surface of the cylinder according to the direction of the angle of attack.

• 산업공학
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• 제12권1호
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• pp.10-18
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• 1999

Job shop manufacturing environments are using the concept of cellular manufacturing systems(CMS) which has several advantages in reducing production lead times, setup times, work-in-process, etc. Utilizing the similarities between cell-machine, part-machine, and the shape/size of parts, CMS can group machines and parts resulting in improved efficiency of this system. However, when grouping machines and parts in machine cells, there inevitably occurs exceptional elements(EEs), which can not operate in the same machine cell. Minimizing these EEs in CMS is a critical point that improving production efficiency. Constraints in machine duplication cost, machining process technology, machining capability, and factory space limitations are main problems that prevent achiving the goal of maintaining an ideal CMS environment. This paper presents an algorithm that minimizes EEs under the constraints of machine duplication cost and factory space limitation. Developing exceptional operation similarity(EOS) by cell-machine incidence matrix and part-machine incidence matrix, it brings the machine cells that operate the parts or not. A mathematical model to minimize machine duplication is developed by EOS, followed by a heuristic algorithm in order to reflect dynamic situation resulting from minimizing exceptional elements process and the mathematical model. A numerical example is provided to illustrate the algorithm.

• 대한기계학회논문집B
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• 제24권7호
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• pp.976-983
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• 2000

The flow characteristics around an elliptic cylinder with axis ratio of AR=2 located near a flat plate were investigated experimentally to study the interaction between the cylinder wake and the turbulent boundary layer. The pressure distributions on the cylinder surface and on the flat plate were measured with varying the angle of attack of the cylinder. In addition, the velocity profiles of wake behind the cylinder were measured using a hot-wire anemometry As the angle of attack increases, the location of peak pressure on the windward and leeward surfaces of the cylinder moves toward the rear and front of the cylinder, respectively. At positive angles of attack, the position of the minimum pressure on the flat plate surface is moved downstream, but it is moved upstream at negative angles of attack. With increasing the angle of attack, the vortex shedding frequency is gradually decreased and the critical angle of attack exists in terms of the gap ratio. By installing the elliptic cylinder at negative angle of attack, the turbulent boundary layer over the flat plate is disturbed more than that at positive incidence. This may be attributed to the shift of separation point on the lower surface of the cylinder due to the presence of a ground plate nearby.

• Tuberculosis and Respiratory Diseases
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• 제60권4호
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• pp.464-468
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• 2006

폐종괴로 발현하는 M. kansasii 감염은 흔하지 않으며 기관지 탄분섬유화증을 동반한 M. kansasii 폐감염에 대한 보고는 아직 없었다. 기저질환 없이 면역력이 정상인 비흡연자에서 우하엽의 폐종괴로 발현하고 기관지 탄분섬유화증을 동반한 M. kansasii 폐감염에 대하여 표준 치료로 호전되고 있는 증례를 경험하였기에 보고하는 바이다.

• Tuberculosis and Respiratory Diseases
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• 제58권6호
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• pp.600-606
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• 2005

Background : The development of bronchoscopic equipment along with the precision of radiographic techniques had reduced the mortality rate of patients with tracheobronchial foreign bodies but has been no change in the incidence of tracheobronchial foreign bodies since their introduction. The aim of this study was to assess the clinical characteristics of a tracheobronchial foreign body aspiration and to evaluate the efficacy of the treatment modality in children and adults. Methods : This is a retrospective review of 64 patients who underwent bronchoscopic procedures for the treatment of aspirated foreign bodies from December 1994 through March 2004 at the Chonnam national university hospital. Results : There were 47 males and 17 females, aged from 1 month to 78 years. Most of the patients had no underlying illness except for one patient with a cerebrovascular accident that contributed to the foreign body aspiration. The most common symptom was cough, which was noted in 54 patients (84.3%). The other presenting symptoms were dyspnea (48.8%), fever (20.3%), sputum (14%), vomiting (7.8%), and chest pain (4.6%). Those whose tracheobronchial foreign bodies were diagnosed more than 2 days after the aspiration (21 patients) were more likely to have pneumonia than those whose foreign bodies were diagnosed within 2 days (p = 0.009). Foreign bodies were visualized in the plain chest radiographs in 12 cases (18.8%), while others showed air trapping (21, 32.8%), pneumonia (15, 23.4%), atelectasis (7, 10.9%), and normal findings (9, 14.1%). The foreign bodies were more frequently found in the right bronchial tree (36) compared with the left bronchial tree (22, p = 0.04). In order to remove the foreign bodies, twenty (31.2%) cases were removed using flexible bronchoscopy, while 42 (65.6%) and 2 (3.2%) cases required rigid bronchoscopy and surgery, respectively. Conclusions : Tracheobronchial Foreign body aspiration had a bimodal age distribution in the infancy and old age around 60 years. They were found more frequently in the right bronchial tree. In addition, patients whose foreign bodies were diagnosed more than 2 days after the aspiration were more likely have a infection. Rigid bronchoscopy is the procedure of choice for uncooperative children and for those with foreign bodies lodged deeply in the small bronchial tree.

• 식물병연구
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• 제21권4호
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• pp.268-272
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• 2015

마늘 세균점무늬병은 국내에서 제주지역 난지형 마늘에서 Pseudomonas syringae pv. morri에 의해 발생하는 세균병해로 주요 병해 중 하나이다. 본 연구는 자연로그를 취한 이항분산에 대한 관측분산의 회귀모델인 binary power law를 이용하여 포장 내 병 발생의 공간분포 특성을 분석하였다. 회귀식의 기울기(b) 값이 1.361로 기준치인 1보다 커 세균점무늬병은 공간적으로 집중분포하고 있었다. 축차표본조사법은 평균이병주율($p_m$)의 추정과 요방제수준($p_t$) 이상 또는 이하 여부를 판단할 수 있도록 개발하였다. 본 연구결과는 기존의 조사지점수 고정 조사 방법에 비해 조사비용 면에서 더 효율적인 동시에 조사결과의 정확도를 더 높일 수 있을 것으로 판단된다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1989-1993
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• 2013

Background: Lung cancer is the most frequent cancer among men and second highest among women overall, including in Turkey. Cigarette smoking is the most important etiologic factor for the development of cancer in both men and women. Objective: To determine the lung cancer incidence in Northeastern Anatolia Region of Turkey with a focus on clinical properties, cancer subtypes, the relationships of tumors with cigarette smoking and radiological properties of the lesions. Materials and Methods: In a retrospective study design, 566 lung cancer cases diagnosed at the Pathology Department of Ataturk University in Erzurum over the last seven years extending from January 2006 to June 2012 were investigated. The results were compared with statistical analyses. Results: The most common histopathological subtype of primary bronchogenic carcinoma in our study was found to be the squamous cell carcinoma, 46.1% (261 out of 566), and the second was small cell lung carcinoma 15.7% (89 out of 566). Based on our data, an overall male predominance was noted with a male/female ratio of 6.1/1. While 296 (52.2%) of the patients were found to be smokers at the time of diagnosis, 125 (22.0%) were nonsmokers and 145 (25.6%) were ex-smokers. Smoking status was found to have a strong correlation with primary lung cancer (p<0.05), and there were significant differences between males and females (p<0.001). Conclusion: Although relative prominence of subtypes of lung cancers differ between Turkish and other populations, lung cancer overall remains as an important health problem in Turkey. Our findings stress the critical need for effective cancer prevention programs such as anti-smoking campaigns.

• 한국임상수의학회지
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• 제34권2호
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• pp.126-131
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• 2017

This study investigated the incidence rate of umbilical hernia (UH) in pig farms and examined the effect of using them as breeding pigs on reproductive traits. The occurrence of UH ranged from 0.1% to 3.0% in pig farms investigated. UH pigs were found in almost all farms except for a single farm in Jeju Island. Spontaneously occurring UH pigs were selected and used for cross breeding tests. UH-related crosses and their progeny showed significant (P < 0.05) differences in gestation period, the numbers of piglets born and alive, and body weights at birth and $21^{st}$ day comparing to those of the control population. UH-related crosses showed longer gestation period, reduced numbers of piglets, and lighter body weights than those from the control population. Interestingly, reduced number of piglets was about one fourth, suggesting that UH inheritance might play a critical role as a lethal gene during embryogenesis. In addition, UH incidence rate in UH-related crosses was significantly (P < 0.05) higher than that in the control except for UH-cross3. However, in the progeny of control cross, a pig also had UH appearance, indicating that porcine UH might be inherited in recessive inheritance mode. Taken together, the results of this study indicate that UH is one of recessively inherited genetic defect that occurs at ordinary times in pig farms, suggesting that the use of UH animals as sire and/or dam may lead to economic losses due to increased gestation period, reduced numbers of piglets born and alive, and lower growth rates after birth of pigs.

• Journal of Pharmaceutical Investigation
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• 제31권1호
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• pp.7-12
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• 2001

Amphotericin B (AmB) is a drug of choice for the treatment of systemic fungal diseases, but its use is considerably limited due to a high incidence of toxicity, particularly nephrotoxicity. It has been demonstrated that the toxicity of AmB is caused by self-aggregated species of the drug and that unaggregated (monomeric) drug is nontoxic but still expresses antifungal activity. Poly (ethylene oxide) (PEO) is a water-soluble polymer, which may impact the aggregation state of AmB. We have studied the aggregation state of AmB as a function of PEO molecular weight and concentration. At 3,000 and 8,000 g/mole, there was minimal or no change of critical aggregation concentration (CAC) of AmB regardless of the concentration of polymer. By contrast at 20,000 g/mole, the CAC of AmB strikingly increased to 24.3 and $37.5\;{\mu}M$ at 5.0% and 10 % w/v of polymer, respectively. The critical overlap concentration (COC) of PEO 20,000 g/mole was 5.5%. It appears that an interaction between monomeric AmB and polymer coil increases above the COC, competing with self-aggregation of the drug. Accordingly, the degree of aggregation of AmB stayed low and the toxicity became less. There was no such effect at 3,000 and 8,000 g/mole of PEO, owing perhaps to small dimensions in comparison to AmB. Based upon these findings, less toxic AmB formulation may be developed by a pharmaceutical technique such as solid dispersion system containing both AmB and PEO 20,000 g/mole.