• Title/Summary/Keyword: Open Problem

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A Study on Fault Model end Performance Evaluation under Power Switch Open Fault in an Inverter-Driven Permanent Magnets Synchronous Motor (영구자석 동기전동기 구동 인버터 스위치의 개방 고장에 의한 제어 특성해석 및 고장모델 연구)

  • Kim, Kyeong-Hwa;Choi, Dong-Uk;Gu, Bon-Gwan;Jung, In-Soung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.6
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    • pp.40-51
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    • 2009
  • To analyze influences under open faults in switching devices of the PWM inverter and under the isolation between the inverter and motor terminal, a faulty model for the inverter-driven permanent magnet synchronous motor is presented. Even though the conventional dq motor model obtained through the transformation of phase voltage model is widely used to analyze and control AC motor, it can not be used under open faults in switching devices since the 3-phase balanced condition is no longer hold under the open fault and it is not easy to obtain motor input voltages in open phase from the pole voltage. To deal with this problem, a faulty model for an inverter-driven permanent magnet synchronous motor is derived by using the line voltage of motor according to switch open, which can be effectively used for performance evaluation of the diagnostic algorithm. The validity of the proposed faulty model is verified through comparative simulations and experiments using DSP TMS320F28335.

A Selection Model for Open Source Software Reuse (재사용을 목적으로 한 오픈소스 모바일 컴포넌트 선정 절차)

  • Sohn, Hyo-jung;Lee, Min-gyu;Seong, Baek-min;Kim, Jong-bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.10a
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    • pp.71-74
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    • 2014
  • Mobile apps have been developed actively using open source software recently. Tend to be used much more than the component of the functional role on the ground that the reuse of components for the User Interface is an open source implementation of the mobile component is easy. The problem is to apply as an open source mobile components selected for this reason all of the existing two studies. It is an open source software selection process and selection procedures shelf components. We revise to conform to existing mobile components selected for the study on open source software selection process in this paper. Can help increase the productivity of the mobile app development by the open source components to meet the functional requirements when developing mobile apps that can be easily retrieved and presented the selection process of this study is effective.

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Space Efficiency Improvement for Open Access Library -Focused on Book-storage Space of Academic Libraries in Province Area- (개가식 도서관의 공간효율 제고 방안 -지역 대학도서관 서고 공간을 중심으로-)

  • Ahn, Joon Suk
    • Journal of the Korean Institute of Rural Architecture
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    • v.17 no.4
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    • pp.67-74
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    • 2015
  • Due to an inability to accommodate for the rapidly increasing number of printed materials, Korean academic libraries are facing serious space shortage problems. Very few academic institutions have the funds to expand existing libraries or construct new facilities in order to accommodate the influx of printed materials. Despite not having the luxury to create new space, many establishments continue to implement the open access system. Seeing that such a system is only user friendly when used in a spacious facility, the maintenance of the open access system is unreasonable. Only few libraries consider the space efficient closed access system which helps to resolve storage space shortage. In the current state of the problem, improving the efficiency to which books are stored in existing storage areas within a library facility is the only appropriate solution. Enacting methods to improve physical space utilization within a fixed volume library facility will undoubtedly diminish the space shortage issue at hand. In this article, several space efficiency improvement approaches are discussed. Methods of book storage plan re-layout (floor, plan, ceiling, height, bookshelf design), book arrangement possibilities, and the reduction of the physical volume of reserved materials are each examined.

A Study on the Open Access Model for Scholarly Communication (정보공유적 모델 기반의 학술커뮤니케이션에 대한 연구: 저작권을 중심으로)

  • 정경희
    • Journal of the Korean Society for information Management
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    • v.19 no.4
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    • pp.384-399
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    • 2002
  • The ownership of scholarly communication, i.e. copyright is very important to solve the problem of access to many academic journals in network environment. The purpose of this article is to give a conceptual model for the open access based scholarly communication. The main point of this model is for the authors of research paper to retain copyright on their works and to license the work whenever it is reproduced or redistributed for non-profit use with academic purpose. And library have to construct full text journal databases under this open access license.

Clinical Experience of Cleft Lip and/or Palate Repair in Complex Congenital Heart Disease (선천성 복잡심장병 환아의 구순 구개열의 치험례)

  • Koh, Kyung Suk;Lee, Sang Hyuk;Eom, Jin Sup
    • Archives of Plastic Surgery
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    • v.32 no.3
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    • pp.385-388
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    • 2005
  • In cleft lip and/or palate patients with the complex congenital heart diseases, surgical repair of the cleft lip and/or palate has been postponed after the open heart surgery because the heart problem of the patient might cause more complications associated with anesthesia and surgery. There has been little report about experiences in the surgical management of these patients and optimal time of surgical intervention. Authors are introducing the experiences of performing corrective surgery of cleft lip and/or palate in the patients with congenital heart diseases before and after the open heart surgery. We managed five patients from May 1992 to March 2004. Two patients were male and the rest were female. One of them had cleft lip alone and others had cleft lip and palate. Two of them underwent delayed cleft lip and/or palate surgery after open heart surgery, and the rest had immediate intervention for cleft lip and/or palate. There was no complication during the operation and postoperative period. There would be no need to delay the corrective surgery of the cleft lip and/or palate after the open heart surgery, if solid medical team approach was available with the pediatric cardiologist and the anesthesiologist.

Surgical Treatment of Empyema with Bronchopleural Fistula (기관지 흉막루의 외과적 치료)

  • 신형주
    • Journal of Chest Surgery
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    • v.23 no.4
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    • pp.750-757
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    • 1990
  • Empyema with bronchopleural fistula is an uncommon, but serious problem. Early diagnosis and adequate drainage of the empyema cavity are well established principles for the initial management of this condition and will enable patient to recover from the toxic effects of loculated pus. 37 patients of empyema with bronchopleural fistula were treated at the department of the chonbuk National University Hospital between 1981 and 1988. The age group of fifty and sixty decades occupied 64.8%. Bacteriologic cultures of the pus were postive in 56.8%. The most common organism of the culture was staphylococci(42.9%). And the others were Pseudomonas(19%). Klebsiella(14.3%), and E. doli. No growth of pathologic organism was reported 43.2%. 24 patients of empyema with bronchopleural fistula were nonoperative causes : There were 10 pulmonary tuberculosis, 3 abscess, 9 ascending infection, one bronchiectasis and one tumor, respectively. The remaining 13 were occurred as postoperative complications ; pneumonectomy in 6, lobectomy in 4, decortication in 2, and lobectomy with segmentectomy in 1. When used as the initial mode of drainage, closed thoracostomy was performed to almost all of the patients, but 4 patients were died during this treatment. Main operations were performed except 4 died patients ; open thoracostomy in 21, open thoracostomy with myoplasty in 3, decortication in 5, decortication with resection in 3, and completion pneumonectomy in 1. Open thoracostomy was performed in 21 patients which results were favorable except one death. Permanent open thoracostomy is an old but still useful minor operation in patients with empyema with bronchopleural fistula. The overall mortality rate was 15% (6 patients) and the causes of the death were respiratory insufficiency or sepsis, or both.

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Arthroscopic and open reduction for ankle fractures (족관절 골절에 대한 관절경적 정복술과 관혈적 정복술)

  • Kim, Dong-Heon;Chang, Byeong-Chun;Lee, Jae-Sung
    • Journal of Korean Foot and Ankle Society
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    • v.2 no.2
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    • pp.82-87
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    • 1998
  • The ankle is a complex structure supporting the entire musculoskeletal system during standing and walking. And so the goals of operative treatment for ankle fractures are to obtain an anatomical reduction that is maintained by stable fixation, resulting in a healed fracture and recovery of normal function. The 64 patients who had ankle fractures were treated by arthroscopic reduction(20 cases) and open reduction (43 cases) in Konkuk university hospital from February 1991 to October 1997 and the results were analyzed in clinical and radiological aspects. The following results were obtained. According to the criteria of Meyer, arthroscopic assisted reduction group had good or excellent results in 18 cases (90%) and open reduction group good or excellent in 35 cases (83%). The difference of the results was not significant statistically, but arthroscopic assisted reduction technique has several advantages over open technique; the best assessment of articular surface, lower wound problem, postoperatively faster rate of rehabilitation and minor discomfort.

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Sharing Product Data among Heterogeneous PDM Systems Using OpenPDM (서로 다른 PDM 시스템 간에 OpenPDM을 이용한 제품데이터의 교환)

  • Yang, Jeong-Sam;Han, Soon-Hung;Mun, Du-Hwan
    • Korean Journal of Computational Design and Engineering
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    • v.13 no.2
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    • pp.89-97
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    • 2008
  • Today's manufacturing environment is becoming a distributed manufacturing process in which a unique and specialized technological background is required in specific domains rather than having a single company execute all the manufacturing processes. This phenomenon is especially true in the automotive industry, where the sharing of product data between companies is rampant; however, this kind of interoperability causes many problems. When each company has its own method of managing product data, the sharing of product data in a distributed environment is a major problem. A data translator module or a data mapping module had to be developed for the exchange of data in heterogeneous systems of product data management (PDM); moreover, this type of module must be continually changed and improved due to the fact that PDM systems change for many reasons. In addition, the growth in corporate partnerships deepens the burden of developing and maintaining this module and creates further data exchange problems due to the increasing complexity of the system. This paper introduces a way of exchanging product data among heterogeneous PDM systems through the use of OpenPDM, which is a kind of virtual data warehouse. The implementation of a PDM integrating system is also discussed with respect to the requirement for a logical integration of product data which are physically distributed.

A Study on the Mathematical Communication Focused on the Students' Level of Mathematical Understanding (학생들의 학습 수준에 따른 수학적 의사소통의 특징 -개방형 문제를 활용한 소집단 협동학습을 중심으로-)

  • Kim, Yeon-Ju;Na, Gwi-Soo
    • Journal of Elementary Mathematics Education in Korea
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    • v.13 no.2
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    • pp.141-161
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    • 2009
  • Mathematical Communication ability can be more developed through sharing thoughts with others. Therefore when we instruct students in math, it is very important for teachers to provide them with opportunity to communicate mathematically. So this study provided open-ended problems in small-group collaborative learning. And we analyzed students' mathematical communication focused on the student's level of understanding. Furthermore, to improve students' mathematical communication ability, this study tries to attract the factors that we should consider the exact date for inserting the open-ended problems into a course of math and the student's level of understanding for selecting suitable open-ended problems.

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A study on the estimate criteria of the business service fee of open source software (오픈소스 소프트웨어 서비스의 비즈니스 대가 산정 기준에 대한 연구)

  • Shim, Ho-sung;Lee, Jae-yun;Chun, Sam-hyun;Kim, Jong-bae
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.63-65
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    • 2014
  • Open source software has a feature that offers its service by the subscription method without getting a license fee. Therefore, this business style needs a different form of estimate criteria from other proprietary software, which is paid by license fees and maintenance service fees. However, consumers, including the public sector, don't understand this feature. This problem has kept the open source software business from attaining prosperity. I would like to provide a model for the estimate criteria that can apply to the open source software business by investigating and developing various advanced research and market examples.

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