• 대한기계학회논문집A
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• 제21권12호
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• pp.1984-1991
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• 1997

Recently burr technology is rising in the fields of the precision manufacturing and the high quality machining, deburring has treated as a difficult problem on going to the high efficiency, automation in the FMS. Removal of burr with various shapes, dimensions and properties couldn't be standardized and has depended on manual treatment. Especially, deburring for cross hole inside owing to passing through out perpendicular to a main hole is more difficult, the electrochemical method is proper as its solution at practical aspects. Burr elimination in the cross hole drilling of governor shaft used in the automobile engine so far has been worked by a manual post-processing by a skillful worker, which becomes a factor of productivity-down and cost-up so that improvement of machining process is needed. Therefore, for the high efficiency and automation of internal deburring in the cross hole, development of electrochemical deburring technology is needed. So, the new process in the burr treatment is supposed. In this study, characteristics of electrochemical deburring through experiments were identified and factors such as electrolytic gap and electorlytic fluid contributed to removal burr height were analyzed. Also, deburring efficiency and electrolytic performance for cross hole were examined according to electrolytic current and electrochemical deburring condition corresponding to acquired edge quality was found out.

• 대한기계학회논문집B
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• 제25권12호
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• pp.1721-1729
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• 2001

The performance of gas turbines is decreased as their operating hours increase. Fouling in the axial compressor is one of main reasons for the performance degradation of gas turbine. Airborne particles entering with air at the inlet into compressor adhere to the blade surface and result in the change of the blade shape, which is closely and sensitively related to the compressor performance. It is difficult to exactly analyze the mechanism of the compressor fouling because the growing process of the fouling is very slow and the dimension of the fouled depth on the blade surface is very small compared with blade dimensions. In this study, an improved analytic method to predict the motion of particles in compressor cascades and their deposition onto blade is proposed. Simulations using proposed method and their comparison with field data demonstrate the feasibility of the model. It if found that some important parameters such as chord length, solidity and number of stages, which represent the characteristics of compressor geometry, are closely related to the fouling phenomena. And, the particle sloe and patterns of their distributions are also Important factors to predict the fouling phenomena in the axial compressor of the gas turbine.

• Restorative Dentistry and Endodontics
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• 제45권1호
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• pp.7.1-7.9
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• 2020

Objectives: This study was performed to assess the anatomy of mandibular first molars. Materials and Methods: In this in vivo study, cone-beam computed tomography (CBCT) volumes of 312 bilateral intact first mandibular molars from 156 patients (79 men and 77 women; average age, 35.6 ± 11.2 years) were investigated in terms of the direction of each canal's curvature in the buccolingual and mesiodistal dimensions (direction of the position of the apex in relation to the longitudinal axis of the root), the presence of an isthmus (a narrow, ribbon-shaped communication between 2 root canals) in 3 segments (0-2, 2-4, and 4-6 mm) from the apex), and the presence and number of accessory canals (smaller canals besides the main root canals, connecting the pulp to the periodontium). Data were analyzed statistically (α = 0.05). Results: Mesiolingual canals were mostly buccally and distally inclined, while mesiobuccal and distolingual canals were mostly distally curved. Isthmuses were more common in younger patients (χ² test, p < 0.05). The average numbers of accessory canals in the apical, middle, and coronal segments were 9.9 ± 4.2, 6.9 ± 2.9, and 9.3 ± 3.0 canals per segment, respectively (analysis of variance, p < 0.001). Age and sex were not associated with the number of accessory canals (p > 0.05). Conclusions: The complex anatomy of these teeth deserves attention during non-surgical or surgical endodontic treatment. Around the apex, isthmuses might be more prevalent in younger and female individuals.

• 한국의류학회지
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• 제16권4호
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• pp.443-455
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• 1992

The purpose of this study is to verify the theoretical model on the clothing satisfaction. Research problems are as following; 1. To identify a causal model on the clothing satisfaction. 2. To examine the causal model by the brand levels. 3. To examine the causal model by the consumer characteristics. The empirical study of the above research problems is carried out by the longitudinal survey. The subjects selected for the final analysis are 362 women living in Seoul and Pusan. The results of our analysis are as following; 1. The main causal course of the clothing satisfaction is that the brand level and the consumer expectation $\rightarrow$ the expectation $\rightarrow$ the perceived performance ($\rightarrow$ the disconfirmation) $\rightarrow$ the clothing satisfaction. Those relevant variables explain $70\%$ of the clothing satisfac-tion variance. Especially, the influence of the perceived performance appears to be greater than that of the disconfirmation. 2. According to our analysis, the expectation influences the clothing satisfaction indirectly through the perceived performance. Especially, the normative expectation exhibits the contrast effect on the disconfirmation, while the predictive expectation exhibits the assimilation effect on the perceived performance. 3. The clothing satisfaction model differs by the brand levels (high price brand vs. moderate price brand) and by the consumer involvement levels (high involvement vs. low involvement). The relevant variables explain $65\%$ of the clothing satisfaction variance in the high price brand, while they explain $77\%$ in the moderate price brand. In the high involvement group, the relevant variables explain $78\%$ of the clothing satisfaction variance and $60\%$ in the low involvement group. In both involvement groups, the most critical direct variable is the perceived perfor-mance. In conclusion, we find that the clothing satisfaction can be explained by three constructs, the expectation, the perceived performance and the disconfirmation. The hypothesis that the two dimensions of the expectation explain the clothing satisfaction better is empirically supported in our study. Finally, we find that the clothing satisfaction models differ between two brand levels and consumer involvement levels.

• 한국문헌정보학회지
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• 제43권4호
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• pp.307-326
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• 2009

자기효능감 개념은 Bandura가 이론화한 이후에 교육, 심리, 경영 등의 분야에서 활발하게 적용되어 왔으며 이를 구체적으로 측정하고자 하는 노력은 관련된 척도의 개발로 나타났다. 하지만 일반적인 자기효능감 척도는 문헌정보학 영역의 상황을 반영하지 못한 점이 있어 정보문해 상황에서의 자기효능감을 보다 잘 표현하고 측정할 수 있는 도구의 개발이 요구되어 왔다. 본 연구는 기존에 유일하게 제시된 척도인 터키의 연구자 Kurbanoglu의 ILSES 척도를 평가하였다. 7개 구성 요소 아래 40문항으로 만들어진 ILSES 척도를 검증하기 위해 400명이 넘는 서울 시내 대학생을 대상으로 설문을 시행하였고 신뢰성 분석과 요인분석을 통해 척도를 평가하였다. 분석의 결과 ILSES 항목들은 비교적 높은 내적 신뢰도를 보인 반면 Kurbanoglu의 연구에서 도출된 요인과 상당히 다른 요인이 도출되었다. 본 연구에서 도출된 6개의 정보문해 자기효능감 요인은 우리나라 대학생들의 정보탐색 및 이용의 독특한 경향을 보여주는 요소들이 포함되어 있다. 한편 도출된 여섯 개의 요소에 대해 문헌정보학 전공자와 비전공자, 저학년과 고학년 사이에서 자기효능감 평균값의 차이는 거의 없는 것으로 나타났다.

• 한국정밀공학회지
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• 제15권3호
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• pp.18-23
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• 1998

This paper describes a research work of developing a computer-aided design of blanking and piercing for irregular-shaped sheet metal products. 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 four main modules, which are input and shape treatment, flat pattern layout, production feasibility check, 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 the dimensions and relationships of parts of the folded product. Also this system can carry out a process planning which is obtained from results of irregular shape of product that was successful in production feasibility check module according to flat pattern layout and generate strip layout drawing in graphic forms. The developed system provides its efficiency for flat pattern layout, and strip layout for the irregularly shaped sheet metal products.

• 터널과지하공간
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• 제11권3호
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• pp.248-256
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• 2001

실린더 컷은 터널 굴착단면의 크기에 관계없이 널리 이용된다. 본 연구에서는 발파당 굴진장을 중대시키기 위하여 종래의 방법과 다른 새로운 방법을 제안하였다. 이 방법의 새로운 패턴은 그림과 같으며, 각 단계별로 상세한 저항선, 공간간격은 별도 그림과 같다. 새로운 실린더 컷 방법과 종래의 방법과의 결과는 다음과 같다. 종래 방법은 굴진장이 천공장의 90∼95%인데 비하여 새로운 방법은 대체로 99.5%이다. 비장약량이 1.363kg/㎥에서 1.297로 약 5% 감소되며, 비천공장이 2.393 m/㎥에서 2.130으로 약 8%o감소 된다. 그밖에 지반진동, 비산, 파쇄암의 크기 등이 종래 방법에 비하여 우수함을 확인하였다.

• 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.

• 보건행정학회지
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• 제18권3호
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• pp.1-17
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• 2008

The measurement and management of patient satisfaction has become one of the key issues in the last two decades. Hospitals must thoroughly understand the needs of their customers and design products and health services that meet and exceed their expectations. The importance-performance analysis(IPA) is a widely used analytical technique that yields strategies for managing customer satisfaction in a variety of applications. IP A is a two-dimensional grid based on customer-perceived importance of quality attributes and attribute performance. Depending on the interplay of these two dimensions, four strategies can be derived. The aim of this study is to develop the management strategies for improving patient satisfaction in university hospitals using the I-P analysis. The attributes on inpatient service quality in 4 university hospitals was investigated using the Martilla and James(l977)' s a mean adjusted I-P grid where the axes of the grid cross at the average rating point of all items. The patient satisfaction questionnaires were completed by 600 hospital inpatients. The main statistical methods are path analysis and IPA with SPSS 12.0 and AMOS 4.0 statistical softwares. The two attributes, physician and medical service, administrative staff kindness attributes position in first quadrant(Keep Up the Good domain). The nurse and nursing service attributes position in second quadrant(Possible Overkill domain). The two attributes, convenience of check-in service, facilities and physical environment position in third quadrant(Low Priority domain). Finally the quality of inpatient service(food etc.) attributes position in fourth quadrant(Concentrate Here domain). These findings show various implications on the development of strategies in university hospitals in the future. It was determined that quality of inpatient service(food etc.) need to concentrate more on investments. These investments include a taste, price, proper provision of food service and quick response of pain management. A low priority was given to investment in streamlining the check-in process of inpatient and hospital facilities and physical environment in the long run.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제7권5호
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• pp.475-488
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• 2001

최근 인터넷을 사용하는 사용자 수가 급격하게 늘어나면서 웹페이지를 효과적으로 디자인하기 위한 여러가지 방법론들이 제시되고 있다. 하지만 이러한 방법론은 웹페이지 디자인 요소 중 기능적 디자인 요소에 치중할 뿐, 감성적 디자인 요소에 대한 과학적 근거를 마련해 주지는 못했다. 본 연구에서는 웹페이지 디자인 요소 중 사용자의 감성에 소구하는 요소를 중심으로 웹페이지 디자인에 대한 감성 과학적 연구를 진행하였다. 이를 위해 본 연구에서는 먼저 감성어휘분석을 통해 사용자가 일반적으로 웹페이지를 보고 느끼는 13개의 감성 차원을 도출하였다. 다음으로 13개 감성차원을 실제 디자이너는 어떤 디자인 요소를 사용하여 구현하는지를 실험실 실험을 통해 분석하였으며, 이를 통해 웹페이지의 디자인 요소를 평가할 수 있는 코딩스킴(Coding Scheme)을 도출하였다. 그리고 실험실 실험을 통해 제작된 52개의 웹페이지를 중심으로 웹페이지의 디자인 요소를 분석하였으며, 동시에 설문조사를 통해 동일한 52개의 웹페이지에 대해 사용자들은 13개 감성 차원을 어느 정도를 느끼는지를 분석하였다. 그리고 이 두 데이터를 이용하여 사용자의 감성에 주요한 영향을 미치는 e자인 요소를 제시하였다. 따라서 본 연구는 사용자에게 특정 감성 차원을 느끼게 하기 위해서 어떤 디자인 요소를 사용해야 하는가에 대한 과학적인 근거를 제시하였다.