• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.10
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• pp.1612-1620
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• 2004

This study presents methods to estimate elastic-plastic crack opening displacement (COD) fur circumferential through-wall cracked pipes for the Leak-Before-Break (LBB) analysis of pressurized piping. Proposed methods are based not only on the GE/EPRI approach but also on the reference stress approach. For each approach, two different estimation schemes are given, one for the case when full stress-strain data are available and the other fur the case when only yield and ultimate tensile strengths are available. For the GE/EPRI approach a robust way of determining the Ramberg-Osgood (R-O) parameters is proposed, not only fur the case when detailed information on full stress-strain data is available but also for the case when only yield and ultimate tensile strengths are available. The COD estimates according to the GE/EPRI approach, using the R-O parameters determined from the proposed R-O fitting procedures, generally compare well with the published pipe test data. For the reference stress approach, the COD estimates according to the method based on both full stress-strain data and limited tensile properties are in good agreement with pipe test data. In conclusion, experimental validation given in the present study provides sufficient confidence in the use of the proposed method to practical LBB analyses even though when information on material's tensile properties is limited.

• International Journal of Highway Engineering
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• v.15 no.5
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• pp.217-226
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• 2013

PURPOSES : Under the capacity conditions with balanced approach flows, roundabouts give less delay than existing signalized intersections; however, flows over 450 vehicles/hour/lane with unbalanced approach flow conditions, roundabouts efficiency drops due to the short time difference between the critical gap and the follow-up headway. The purpose of this study is developing a roundabout Signal Metering operation method by considering approach lanes degree of saturation. METHODS : A four-way-approach with one-lane roundabout is selected to compare the Signal Metering performance for the case of 16 different unbalanced flow conditions. Based on these traffic conditions, the performance is evaluated for 64 different cases of Signal Metering combinations by using SIDRA software. A degree of saturation(V/C ratio) sum for two adjoined approaches is used for the performance index of choosing Metered Approach and Controlling Approach. RESULTS : When the V/C ratio sum is 0.29~0.81 and Metered Approach flow is less than Controlling Approach flow, the average delay saving per vehicle is about 7 seconds; however, after this rage the delay saving decreases gradually until the V/C ratio sum reaches around 1.0. The range of V/C ratio sum 0.93~1.09 provides average delay saving per vehicle about 3 seconds. In case of V/C ratio sum is grater than 1.0 and the flows of Metered Approach is grater than Controlling Approach, the average delay per vehicle increases 3~11 times respectively. CONCLUSIONS : As expected, the Signal Metering provides substantial improvements in delay saving for the case of V/C ratio sum is 0.3~1.0 under the traffic flow conditions of Metered Approach is less than Controlling Approach.

• Knowledge Management Research
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• v.9 no.4
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• pp.143-156
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• 2008

The main purpose of this study is to suggest a way that how government innovation ecosystem can be successfully managed by applying neuro-cybernetics approach. Innovation ecosystem is not a rare phenomenon around us. Especially national innovation managed by government relies on heavily innovation ecosystem. Unfortunately discussions of successful management of this ecosystem are rare. This study strongly urged necessity of such management by observing the case of introduction of CDMA mobile communication technology in Korea. Neuro-cybernetics was suggested as one alternative approach for the such management.

• Journal of The Korean Association For Science Education
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• v.23 no.4
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• pp.331-340
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• 2003

This paper presents a case study of the student's culture as a component of conceptual ecology that affects discussions and discourses in the science classroom. The present study was conducted using a naturalistic approach, mainly through observing a science class of a middle school in Seoul, Korea, and through semistructured interviews. The case showed that the science classroom culture can be identified in four aspects: (1) knowledge; (2) the teacher; (3) classmates; and (4) self. These cultural aspects were strongly related to each other and functioned as constraints in discussions and discourses of the science classroom. For successful discussions and discourses, it is necessary to consider students' cultural aspects: epistemological views on knowledge, the teacher-student and student-student relationships, and the role of self in the discussions and discourses.

• Proceedings of the Korean Society for Language and Information Conference
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• 2005.06a
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• pp.143-150
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• 2005

• The Mathematical Education
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• v.57 no.4
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• pp.433-452
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• 2018

The purpose of this study is to provide implications for improvement of mathematics textbook based on discursive approach to textbook analysis that complementarily combines a communicational approach to cognition and social semiotics. For this purpose, we reconstructed an analytic framework for discursive approach to written discourses of Korean textbook and CMP, and applied it to our analysis. Results show that several characteristics in meanings were developed by the use of words and visual mediators. First, in the case of ideational meaning, there were qualitative and quantitative differences between vocabularies used and between information addressed by visual mediators. Second, in the case of structural meaning, an offer and application of procedure was emphasized in a Korean textbook, whereas expectation and selection experiences of diverse possibilities for problem solving was underlined in CMP. In the case interpersonal meaning of student-author, imperative instructions were paid attentions in a Korean textbook. In contrast, students' interdependence and active participation were stressed in CMP. Therefore, this study addressed ideas about how to analyze mathematics textbooks based on integrated meanings developed by the use of words and visual mediators. In addition, it distributes implications for improvements of Korean mathematics textbooks through the analytic framework of both mathematical meanings and interpersonal meanings of student-author.

• Journal of Information Technology Applications and Management
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• v.22 no.1
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• pp.109-130
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• 2015

This study aims to provide the results of a case study, based on the action research approach, in which an user-oriented management system for enterprise information systems operational performance is successful developed and applied. This study performs the research and summarizes the results by adopting 5-step approach of action research, i.e., diagnosing, action planning, action taking, evaluating and specifying learning. The most important lessons learned from the study include (1) operation performance measures should be established to be shared by the management and users; (2) evaluation and improvement activities should be performed continually; and (3) formula to calculate the measure should be evolved so that improvement initiatives can be identified. The results of the study are expected to provide the companies intending to develop a management system for enterprise information systems operational performance with the practical and useful information. In addition, it is expected to suggest the research results that can be utilized as a basis for future research in this area.

• Journal of Information Technology Applications and Management
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• v.14 no.3
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• pp.1-14
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• 2007

Recently. interests in IT Service Management (ITSM) are increasing internationally as well as domestically. In order to realize the benefits from ITSM, it is necessary to institutionalize it as a culture of the organization through effective change management. One of the most promising approach of effective change management is a Six Sigma technique. In this study, we analyze a success case in which 6 Sigma was applied to Service Desk function which is one of the most important functions of ITSM. Through the analyses, this study aims to propose a feasible and specific approach to institutionalize ITSM. To accomplish the objective. the study analyzed specific methods of application of 6 Sigma to ITSM. performance of the project and future directions based on interview and project document/deliverable review. This study could not provide detailed performance measures due to lack of previous research on this topic and difficulty of obtaining quantitative data. However. this study has contributed to proposing a direction to institutionalize ITSM in organizations by analyzing a feasibility of 6 Sigma in implementing ITSM.

• Archives of Plastic Surgery
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• v.35 no.2
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• pp.152-158
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• 2008

Purpose: Mandibulotomy approach and mandible sparing approach are most common methods for oropharyngeal cancer surgery. Good surgical view and convenience of flap inset are advantages of mandibulotomy approach but deformity of mandible contour, postoperative malocclusion and radionecrosis are its limitations. To make up for the limitations, mandible sparing method is commonly performed, but limited surgical view and difficulties of flap inset are the weak points of this approach. The purpose of the study is to compare mandibulotomy and mandible sparing approaches in postoperative complications and progression of the treatment in oropharyngeal cancer operation and reconstruction. Methods: Single reconstructive microsurgeon operated for oropharyngeal cancer patients with different surgeons of head and neck department who prefer mandibulotomy and mandible sparing approach respectively, and we compared the frequency of postoperative complication, operation time, duration of hospitalization and recurrence rate between two different surgical approaches. Results: Mandibulotomy approach was used in 18 patients and mandible sparing approach was used in 15 patients. In mandibulotomy approach, there happened one case of teeth injury and one case of necrosis of skin and gingiva, but there happened no malocclusion and radionecrosis. In mandible sparing approach, there were 3 cases of fistula and 2 cases of infection which are significantly higher than mandibulotomy approach. There were no significant differences between early regional recurrence and duration of hospitalization. Conclusion: In this study we compared two different methods for the surgical approach in oropharyngeal cancer surgery. As mandible sparing approach has difficulties of limited surgical view, it can be used for the limited indications of anterior tongue and mouth floor cancer. Mandibulotomy approach has advantages of good surgical view and convenience of flap inset. In this method preservation of gingival tissue, watertight fashion suture, delicate osteotomy and plate fixation to maintain occlusion are the key points for the successful results.

• International Journal of Quality Innovation
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• v.7 no.3
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• pp.98-106
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• 2006

Nowadays, agro-firms are confronted with competition from global suppliers in both domestic and export markets. Such competition in sustainable agro-operations is expected to intensify. The survival of these firms in developing countries urgently requires a significant transformation to be competitive. This paper discusses the rationale of adopting a national innovation (NI) approach from an industry-wide perspective. In order to attain sustainable agro-operations in developing countries, the approach stresses appropriate scientific and technological applications and effective linkages of technology transfer via the network between public and private institutions, universities and other research institutions. Central to this approach is the development of the agro-industrial sector whereby agri-chains are formed. An illustrated case of the NI approach is presented with respect to a small island developing state, the Republic of Trinidad and Tobago.