• Title/Summary/Keyword: Case Study Approach

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A Case Study of Enhancing Flame Retardancy of Mixture Material (혼합물 소재의 난연성 향상을 위한 실험연구 사례)

  • Byun, Jai-Hyun;Jung, Chun-Sik;Kim, Donghak;Park, Kyu-Hwan
    • Journal of Korean Society for Quality Management
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    • v.47 no.3
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    • pp.631-639
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    • 2019
  • Purpose: In this paper we present a case study of applying quick and easy experimental design approach to develop a Halogen free flame retardant material for cellular phone charger cable. Methods: We employ sequential experimentation of mixture design, verification design, and factorial design. A quick and easy approach is adopted based on data investigation and graphical method instead of strict statistical analysis, which helped enhancing smooth communication with the engineers and speeding up the development process. Results: Flame retardant material in pellet type produced from the optimal condition is transported to the customer and tested, to pass the customer retardancy criteria. Conclusion: The quick and easy experimental design approach is considered to be useful in this case study.

A CLINICAL STUDY ON THE APPLICATION OF LABIO-MANDIBULOTOMY APPROACH FOR ORAL AND OROPHARYNGEAL TUMORS (구강 및 구인두종양수술시 구순-하악골이단 접근법의 이용에 관한 임상적 연구)

  • Pyo, Sung-woon
    • Maxillofacial Plastic and Reconstructive Surgery
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    • v.21 no.2
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    • pp.225-230
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    • 1999
  • The labiomandibulotomy approch to the oral cavity and oropharygeal region was first described by Roux in 1836 and become popular for oral and oropharyngeal tumors in cases where there are no clinical and radiological signs of mandible invasion. Anterior labiomandibulotomy and swing procedure provides excellent access and facilitate a mandibular resection and subsequent repair. In last two years, 8 cases of oral and oropharyngeal tumors were treated by this approach at the Dept. of Oral & Maxillofacial Surgery, Holy Family Hospital, Catholic University of Korea. And we analyzed postoperative complications as well as functional evaluations, and the results were as follows; In 4 cases, marginal mandibulectomy were combined with labiomandibulotomy and in case of malignancies, neck dissection was performed simultaneously. In almost case, plate and miniscrew fixation was used for osteotomy sites. Histologic evaluation of the resection margins of the specimens revealed tumor free in all cases. The postoperative complications were occured in 3 cases, one case of nonunion, one case of orocutaneous fistula, and one case of wound dehisence. Occlusal stability, jaw movement and swallowing function were acceptable postoperatively in 3 months. From above results, we concluded that, this approach not only provides wide exposure, permitting radical removal of benign and malignant lesions but also preserves function with minimal complications.

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A Study about Measurement Model of Long Term Performance in Stock Split (주식분할의 장기성과 측정 모델에 대한 연구)

  • Shin, Yeon-Soo
    • The Journal of Information Technology
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    • v.9 no.3
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    • pp.77-89
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    • 2006
  • The event study analyzes returns around event date at a time. Event study provides estimation periods and cumulative returns. Stock split announcements are generally associated with positive abnormal returns. It is important to investigate the responses of stocks to new information contained in the announcements of stock splits. So It is important to study the long term performance in the case of Stock Split. This Study forced to two approach method in evaluating the performance, the event time portfolio approach and calendar time portfolio approach. The event time portfolio approach exists the CAR model, BHAR model and WR model. And the calendar time portfolio approach has the 3 factor model, 4 factor model, CTAR model, and RATS model.

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An Anterosuperior Deltoid Splitting Approach for Plate Fixation of Proximal Humeral Fractures

  • Shin, Dong-Ju;Byun, Young-Soo;Cho, Young-Ho;Park, Ki-Hong;Yoo, Hyun-Seong
    • Clinics in Shoulder and Elbow
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    • v.18 no.1
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    • pp.2-7
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    • 2015
  • Background: The purpose of this study was to evaluate the usefulness and safety of the anterosuperior deltoid splitting approach for fixation of displaced proximal humeral fractures by analyzing the surgical outcomes. Methods: Twenty-three patients who could be followed-up for at least 8 months after the treatment of displaced proximal humeral fractures through the anterosuperior deltoid splitting approach were enrolled. We evaluated the reduction of the fractures and surgery-related complications at the last follow-up using X-ray results and clinical outcomes comprising the University of California at Los Angeles (UCLA) scoring system and the Korean Shoulder Society (KSS) score. Results: At the last follow-up of patients treated using the anterosuperior deltoid splitting approach for internal fixation of proximal humeral fractures, we found 22 cases (95.6%) of bone union, a mean UCLA score of 28.3 (range, 15 to 34) and a mean KSS score of 82.1 (range, 67 to 95). Various surgery-related complications were noted; a case of varus malunion after fracture displacement, a case of nonunion, a case of delayed union, two cases of impingement, and a case of partial axillary nerve injury, which recovered completely through the follow-up. Conclusions: Plate fixation using the anterosuperior deltoid splitting approach could be another reliable option for treating displaced proximal humeral fractures.

Application of Dynamic Probabilistic Safety Assessment Approach for Accident Sequence Precursor Analysis: Case Study for Steam Generator Tube Rupture

  • Lee, Hansul;Kim, Taewan;Heo, Gyunyoung
    • Nuclear Engineering and Technology
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    • v.49 no.2
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    • pp.306-312
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    • 2017
  • The purpose of this research is to introduce the technical standard of accident sequence precursor (ASP) analysis, and to propose a case study using the dynamic-probabilistic safety assessment (D-PSA) approach. The D-PSA approach can aid in the determination of high-risk/low-frequency accident scenarios from all potential scenarios. It can also be used to investigate the dynamic interaction between the physical state and the actions of the operator in an accident situation for risk quantification. This approach lends significant potential for safety analysis. Furthermore, the D-PSA approach provides a more realistic risk assessment by minimizing assumptions used in the conventional PSA model so-called the static-PSA model, which are relatively static in comparison. We performed risk quantification of a steam generator tube rupture (SGTR) accident using the dynamic event tree (DET) methodology, which is the most widely used methodology in D-PSA. The risk quantification results of D-PSA and S-PSA are compared and evaluated. Suggestions and recommendations for using D-PSA are described in order to provide a technical perspective.

Assessment of Public Engagement Approach in Various Project Stages: The Case Study of Central Market, Hong Kong

  • Wong, Crystal;Chan, Icy;Lam, Lily;Zayed, Tarek;Sun, Yi
    • International conference on construction engineering and project management
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    • 2020.12a
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    • pp.267-277
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    • 2020
  • The present research evaluates the public engagement approach in various project stages. Hong Kong had long been criticized as top-down and executive-led jurisdiction by overlooking the importance of cultural heritage and public concerns on public projects. It was suggested to the government to engage public and provide sufficient public consultation. Thereby, the government announced a series of revitalization and conversion measures in Policy Address in 2008. To carry out the measures, there were voices, because of diverse and sometimes conflicting interests, over the effect of revitalization project. On the other hand, studies reveal that there are benefits of revitalization and enhancement of public engagement approach. In pursuit of the subject, the present research aims at studying the Central Market as a case study pilot project. In October 2009, the Policy Address announced that the Central Market be revitalized. Tasked to implement the project, Urban Renewal Authority (URA) continued to adopt the people-oriented approach as the guiding principle in its core business and in heritage preservation and revitalization so as to create a sustainable development. Between government and the public, URA acts as a bridge for communication. As between URA and the public, URA conducted public consultation, set up an ad-hoc committee in January 2016 to be in charge of the project and will continuously inform the government and public with the updates and project progress. The main objectives of the present research are to assess the advantages and challenges in different stages of public engagement approach, to evaluate the engagement system, to give a comprehensive view for participation of stakeholders, and to find out effective strategies to enhance civil engagement. Research was achieved through interviews to key persons in the project, questionnaire that was distributed to community and experts in the field. Case Study of the Central Market was studied and investigated using different sources, such as newspapers, journals, etc, to evaluate the degree of public engagement in the project. Both detailed qualitative methodological approaches of interview, questionnaire, and case study, act as a synergy to demonstrate the research objectives and provide the comprehensive perceptions on the revitalization project. The results show that public participants in revitalized project have generated considerable value enhancements to social-cultural, environmental, political and economic aspect. This study provides valuable insights that the public participation can make positive contribution to sustainability in the city. The findings indicate that no any single system is flawless therefore seeking both public opinions and professional advices are also important as a comprehensive approach to achieve higher sustainability of the building.

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A New Hybrid Strategy for the Optimization of Xhemical Processing System

  • Cho, In-Ho;Yoon, En-Sup
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.848-855
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    • 1989
  • By structural comparison of process optimization strategies based on Simultaneous Modular Approach, they can be classified into two groups : the Sequential Module Based Approach and the Two-Tier Approach. The Sequential Module Based Approach needs rigorous models and a set of accurate solutions are guranteed. However, it requires large amount of computation time. In the Two-Tier Approach composed of rigorous and simplified models, optimization calculation uses simplified models, therefore comparatively smaller amount of computation time is required but the obtained solutions may not be accurate. These optimization problems were somewhat improved by the alternate application of the two strategies. In this study, improved optimization strategy is suggested, in which Jacobian Matrix is modified to accomodate the strong points of above mentioned strategies. The results of case study show that this approach is superior to the other strategies.

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Changes of Floor Plans in the Entry and Transfer Spaces of Single Detached Houses - A Case of the City of Chungju, Checheon and Wonju - (진입과 전이공간 특성에 따른 단독주택 평면류형 변화 연구 - 충주시, 제천시, 원주시 사례를 중심으로 -)

  • 신동규
    • Journal of the Korean housing association
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    • v.14 no.4
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    • pp.39-48
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    • 2003
  • The purpose of this study was to analyze the changes of floor plans in the entry and transfer spaces of single detached houses. The sample size was 185 households in Chungju, Jechon and Wonju Which are small cities in the central region of Korea. The results of the study are as follows: Firstly, the approach and transfer spaces show various changes and those are important factors which symbolize the housing plane typology transformations of the research areas. Secondly, the approach direction to the indoor space was more adopted a front approach in 1960's and 1970's, it is a side approach in 1980's, and a back side approach in 1990's. Thirdly, as the stage of the transfer space increased, the detached house planes have been changing to the direction, the depth of space comes to be deep, spatial function to be fixed, and privacy of bed rooms to be increased.

A study on the H_$\infty$ robust controller of induction motors (유도전동기의 H_$\infty$강인제어에 관한 연구)

  • 김민찬;박승규;진승오
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.1448-1451
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    • 1997
  • In this paper, a speed control of nin-servo induction motor is considered. In this case, it is difficult to satisfy precise control performance. SO H.inf. robust controller is designed for this problem by usign polynomial approach and Youla parameterization.

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The Effects of Postural Control based on Bobath Approach for Body Schema and Visual Perception of Middle Cerebral Artery Infarcts : Case Report (보봐스 개념에 기초한 중대뇌동맥 경색 환자의 자세조절이 신체도식과 시지각에 미치는 영향 : 단일사례연구)

  • Lee, Dae-Hee;Ro, Hyo-Lyun
    • Journal of the Korean Society of Physical Medicine
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    • v.4 no.3
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    • pp.193-200
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    • 2009
  • Purpose:In this study is to verify the effects postural control training based on Bobath approach for body schema and visual perception on Middle Cerebral Artery(MCA) Infarcts. Methods:The subject was a 46 years old man with MCA infaction, lives in B city. An AB design for a single-subject research was used for this study. The procedures consisted of 1 time of baseline phase(A), 20 times of treatment phase(B). We applied the Bobath approach at the subject. Treatments included to facilitate trunk alignment and stability, and to train weight bearing and shifting, to facilitate pelvis movement, and to train walk especially stance phase and assist up-down stairs locomotion in environment similar to actual daily life. Results:With this treatment, the majority of body schema and visual perception and postural control was improved in treatment phase compared with in baseline phase. Therefore, this study supported the effectiveness of postural control training based on Bobath approach for body sechma and visual perception of hemiplegia. Conculusion:This study is integrated postural control training with Bobath approach that are widespread for hemiplegia and measured outcomes based on individualized therapy goals. Consequently the study is suggested the meaning of quality effectiveness of Bobath approach.

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