• Title/Summary/Keyword: Operating Experiences

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Online Automatic Gauge Controller Tuning Method by using Neuro-Fuzzy Model in a Hot Rolling Plant

  • Choi, Sung-Hoo;Lee, Young-Kow;Kim, Sang-Woo;Hong, Sung-Chul
    • 제어로봇시스템학회:학술대회논문집
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    • 2005.06a
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    • pp.1539-1544
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    • 2005
  • The gauge control of the fishing mill is very important because more and more accurately sized hot rolled coils are demanded by customers recently. Because the mill constant and the plasticity coefficient vary with the specifications of the mill, the classification of steel, the strip width, the strip thickness and the slab temperature, the variation of these parameters should be considered in the automatic gauge control system(AGC). Generally, the AGC gain is used to minimize the effect of the uncertain parameters. In a practical field, operators set the AGC gain as a constant value calculated by FSU (Finishing-mill Set-Up model) and it is not changed during the operating time. In this paper, the thickness data signals that occupy different frequency bands are respectively extracted by adaptive filters and then the main cause of the thickness variation is analyzed. Additionally, the AGC gain is adaptively tuned to reduce this variation using the online tuning model. Especially ANFIS(Adaptive-Neuro-based Fuzzy Interface System) which unifies both fuzzy logics and neural networks, is used for this gain adjustment system because fuzzy logics use the professionals' experiences about the uncertainty and the nonlinearity of the system. Simulation is performed by using POSCO's data and the results show that proposed on-line gain adjustment algorithm has a good performance.

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Development of the closed-loop Joule-Thomson cryoablation device for long area cooling

  • Lee, Cheonkyu;Park, Inmyong;Yoo, Donggyu;Jeong, Sangkwon;Park, Sang Woo
    • Progress in Superconductivity and Cryogenics
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    • v.15 no.3
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    • pp.40-48
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    • 2013
  • Cryoablation device is a surgical instrument to produce the cooling effect to destroy detrimental biological tissue by utilizing low temperature around 110 K. Usually, this device has the concentrated cooling region, so that it is suitable for concentrated and thick target. Accordingly, it is hard to apply this device for the target which is distributed and thin target. In this study, the design procedure of a closed-loop cryoablation device with multiple J-T expansion part is developed for the treatment of incompetent of great saphenous vein. The developed cyoablation device is designed with the analysis of 1-dimensional (1-D) bio-heat equation. The energy balance is considered to determine the minimum mass flow rate of refrigerant for consecutive flow boiling to develop the uniform cooling temperature. Azeotropic mixed refrigerant R410A and zeotropic mixed refrigerant (MR) of R22 ($CHClF_2$) and R23 ($CHF_3$) are utilized as operating fluids of the developed cryoablation device to form the sufficient temperature and to verify the quality of the inside of cryoablation probe. The experimental results of R410A and the zeotropic MR show the temperature non-uniformity over the range are $244.8K{\pm}2.7K$ and $239.8K{\pm}4.7K$ respectively. The experimental results demonstrate that the probe experiences the consecutive flow boiling over the target range of 200 mm.

The Development of US Navy's Maritime Strategy and the ROK's Tasks with a Focus on the Roles of Aircraft Carrier (미(美) 해군의 해양전략 발전과 우리의 과제 - 항모운용을 중심으로 -)

  • Kwon, Young-Il
    • Strategy21
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    • s.41
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    • pp.30-51
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    • 2017
  • Neighboring powers in the Korean Peninsula have started to develop and operate aircraft carriers or equivalent forces to cope with rising North Korean nuclear and missile threats and also to show its national might. For example, the United States has added a aircraft carrier from the 3rd fleet to western pacific theater of operation, while Peoples Republic of China is undergoing operational test of Liaoning as well as preparing for christening of its 2nd aircraft carrier. Japan is flexing its muscle as well by deploying Izumo capable of operating F-35B to Southeast Asia to participate in multilateral exercises starting this year. It is a high time to know more about aircraft carriers or similar types in terms of maritime strategy and history. The U.S. has had by far the vast amount of experiences in utilizing aircraft carrier that it would be beneficial for us to examine U.S. perspectives and its application in the Korean Peninsula. It will provide us with insights to understand and predict what it would be like in times of crisis in the Korean Peninsula in the perspective of aircraft carrier's involvement. This paper intends to show some aspects of future conflicts in the Korean Peninsula and how the ROK Navy can best be ready for such situation. For research purpose, U.S. maritime strategy has been developed in stages ; establishment phase, WWI phase, WWII phase, Cold war phase, post Cold war phase. Each phase includes such factors as threats, strategic concept, applications, and ways to improve maritime strategy. Finally, the role of aircraft carrier based on past history as well as future conflict shines the importance to have power projection capabilities for the ROK Navy. The intrinsic nature of the navy in the world is to project power ashore just as history proved it.

A Study on the Operations of School Safety Experience Education Space (초등학교 안전체험교육 공간 운영 방안에 관한 연구)

  • Lee, Geun-Im;Lee, Yong-Hwan
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.16 no.3
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    • pp.61-68
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    • 2017
  • The purpose of this study is to suggest the necessary measures for the school safety experience education space to provide the elementary school students with the ability to provide safety education through experiences routinely and repeatedly. For this purpose, we investigated the conditions of safety experience in Jeollabuk-do and the case of other cities as a factor for operating the school safety experience educational space. In order to clarify the appropriateness of this, a questionnaire was conducted for the teachers in the local area. As a result of the analysis, it was found that the use of two classrooms in the place and the scale in the operation of the school safety experiential education space should be sought in various places such as hall, multipurpose room, and gymnasium according to the school condition. Experiential areas should be operated by elementary school students customized, but specialized facilities or large scale should be used for professional safety experience facilities. For efficient operation, the base school wanted to be located in a place where accessibility of other school students was easy, and that a school with sufficient space would be selected.

Emergency Surgical Management of Traumatic Cardiac Injury in Single Institution for Three Years

  • Joo, Seok;Ma, Dae Sung;Jeon, Yang Bin;Hyun, Sung Youl
    • Journal of Trauma and Injury
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    • v.30 no.4
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    • pp.166-172
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    • 2017
  • Purpose: Thoracic traumas represent 10-15% of all traumas and are responsible for 25% of all trauma mortalities. Traumatic cardiac injury (TCI) is one of the major causes of death in trauma patients, rarely present in living patients who are transferred to the hospital. TCI is a challenge for trauma surgeons as it provides a short therapeutic window and the management is often dictated by the underlying mechanism and hemodynamic status. This study is to describe our experiences about emergency cardiac surgery in TCI. Methods: This is a retrospective clinical analysis of patients who had undergone emergency cardiac surgery in our trauma center from January 2014 to December 2016. Demographics, physiologic data, mechanism of injuries, the timing of surgical interventions, surgical approaches and outcomes were reviewed. Results: The number of trauma patients who arrived at our hospital during the study period was 9,501. Among them, 884 had chest injuries, 434 patients were evaluated to have over 3 abbreviated injury scale (AIS) about the chest. Cardiac surgeries were performed in 18 patients, and 13 (72.2%) of them were male. The median age was 47.0 years (quartiles 35.0, 55.3). Eleven patients (61.1%) had penetrating traumas. Prehospital cardiopulmonary resuscitations (CPR) were performed in 4 patients (22.2%). All of them had undergone emergency department thoracotomy (EDT), and they were transferred to the operating room for definitive repair of the cardiac injury, but all of them expired in the intensive care unit. Most commonly performed surgical incision was median sternotomy (n=13, 72.2%). The majority site of injury was right ventricle (n=11, 61.1%). The mortality rate was 22.2% (n=4). Conclusions: This study suggests that penetrating cardiac injuries are more often than blunt cardiac injury in TCI, and the majority site of injury is right ventricle. Also, it suggests prehospital CPR and EDT are significantly responsible for high mortality in TCI.

A Development of Design Guidelines for the Negative Pressured Isolation Units Controlling Severe Respiratory Infectious Disease (중증 호흡기 감염병 진료를 고려한 음압격리병동부의 건축계획)

  • Kwon, Soon Jung;Yoon, Hyungjin
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.22 no.3
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    • pp.45-56
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    • 2016
  • Purpose: The MERS(Middle East Respiratory Syndrome) outbreaks in Korea highlighted dramatically the failings of traditional hospital environment for controlling or preventing infections among both patients and healthcare workers. MERS is transmitted by droplets that can be airborne over a limited area. The point should be emphasized that MERS in South Korea was predominantly a hospital-acquired (not a community-acquired) infection, because approximately 93% of MERS cases were resulted from exposure in hospital settings. This paper tries to suggest the design guidelines of negative pressured isolation ward for the sake of proper control of severe respiratory infectious diseases. Methods: Literature survey on the design guideline and regulations of airborne infection wards in Korea, Europe U.K. and CDC of U.S. have been carries out. 4 special infection wards in Hongkong, Germany, Japan and Korea have been surveyed in order to make the best use of the experiences related to facility design and operations. Results: Operating system influencing the facility design, space organizations of infectious ward including required space and zoning, and circulations of patients, staffs and materials are proposed. Implications: The results of this paper can be the basic data for the design of the airborne infection ward and relevant regulations. Afterwards in-depth study such as the development of space standards for the single bedroom, locker room and so on could be explored.

ELECTROSURGERY IN DENTAL PRACTICE-A CASE REPORT (Electrosurgery를 이용한 치료증례)

  • Yoon, Jae-Woong;Lee, Sang-Hoon;Lee, Kwang-Soo;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.3
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    • pp.631-639
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    • 1996
  • Electrosurgical technique have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Electrosurgery is a surgical procedure performed on soft tissue utilizing controlled high frequency electricaI(radio-frequency) currents in the range of 1,500,000 to 7,500,000 cyclesper second. The radio-frequency energy used in electrosurgery is able to cut and coagulate tissue because it focuses the energy at the small, active electrode. Advantages of electrosurgery for soft-tissue management during dental procedures include improved hemostasis, ease of tissue modification, improved visibility and so on, but adverse healing responses-including necrosis of soft tissue and sequestration of alveolar bone-have been reported. The present report provides examples of treatment of soft tissue and pulp tissue of primary teeth by electrosurgery. The results are as follows; 1. Electrosurgical techniques can be used for various procedures in pedodontics. 2. Electrosurgical procedures provide improved hemostasis and visibility in the operating field, which enable to remove, reshape, and contour soft tissues easily. 3. In pulpotomy technique, it was difficult to expect the variable pulpal response based on the degree of heat accumulation and the conditions of pulp tissues. Therefore, electrosurgical pulpotomy could not be considered as a method superior to formocresol pulpotomy. 4. A greater degree of dexterity and experiences in manipulation of the electrode is required compared with the conventional scalpel surgery.

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A Study on Performance Level for Universal Precautions on Blood-Borne Infections among Nurses in Hospitals (임상 간호사의 혈액매개감염 주의지침에 대한 수행정도)

  • An, Ji-Yeon;Lee, Young-Mi;Song, Jung-Hee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.16 no.1
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    • pp.92-100
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    • 2010
  • Purpose: This study was conducted to investigate the cognition level and the performance level of universal precautions on blood-borne infections and to analyze related-factors on the performance level for universal precautions among the nurses. Method: A total of 166 nurses participated in the survey. We performed multiple linear regression to assess the related-factors on the performance level for universal precautions. Result: The mean scores of cognition and performance level for universal precautions were 65.61(${\pm}8.74$) and 53.98(${\pm}8.42$) respectively. The mean score of the cognition level was significantly lower than the performance level in all items. The cognition level was associated with the working field. The performance level was highest for nurses working over 36 years, nurses in university hospitals, and nurses in the operating room. The cognitive level for universal precautions, education level, exposure to blood-borne infection, family's income, and marital status significantly predicted the performance level for universal precautions in the multiple linear regression model (Adjusted $R^2=0.42$). Conclusion: The cognition level for universal precautions is the strongest predictor on the performance level for universal precautions. An integrated approach should incorporate training experiences to improve cognition and perception of risk on universal precautions for preventing blood-borne infections.

Designing a Web-based Operation Management System for Supporting Clerical Works in Camp (웹기반의 캠프 사무운영 시스템의 설계)

  • Kim, Jun-Woo;Lee, Jang-Hee
    • The Journal of the Korea Contents Association
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    • v.10 no.3
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    • pp.326-336
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    • 2010
  • Camps that provide students with edutainment and cooperative work experiences gain a great popularity worldwide. Accordingly, many camp programs with a variety of subjects and contents have been developed and introduced. The operations managements related to the camp, however, has not been nearly dealt with and the camp staffs in practical camp programs have had heavy burden of clerical works during the camp. To address this problem, this study designed a new operation system for clerical works in camp (OSCWC) for consistently managing associated data by its database and automatically providing camp-related documents via internet. In this study, we validated its effectiveness by applying an its web-based prototype to real data of previous camp case. The camp staffs can handle significant camp-related works and enhance the quality of camp program by reducing miscellaneous works through the use of OSCWC. As a result, the system will help to reduce total operating cost of camp.

Endoscopic Surgery for Pituitary Tumor

  • Kim, Dong-Hyun;Kim, Kyu-Hong;Cho, Young-Woon;Kim, Joon-Soo;Lee, In-Chang;Bae, Sang-Do
    • Journal of Korean Neurosurgical Society
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    • v.37 no.1
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    • pp.20-24
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    • 2005
  • Objective: The purpose of this study is to assess the efficacy and advantages of an endoscopic endonasal approach for the treatment of pituitary tumors. Methods: We retrospectively analyzed the records of 31 patients with pituitary tumors having endoscopic endonasal surgery between March 1999 and August 2003. Results: Among 31 patients with pituitary adenomas, 25 (81%) patients exhibited gross total removal of tumor on postoperative MRI within 3 days after surgery. Among 6 patients removed subtotally, 2 had only radiosurgery, 3 have had periodic follow-up MRIs and one patient with large extended tumor (grade IV, Stage E) had secondary transcranial removal of tumor before radiosurgery. Postoperative complications included cerebrospinal fluid leak in 2 patients, sinusitis in 1 patient, and one patient died due to unexpected intracerebral hemorrhage on 5 days after surgery. Besides considerable experiences with this approach are needed because of narrow working channel to the sella turcica, the results of our study showed following advantages of this procedure: visualization of areas not seen with the operating microscope, elimination of oronasal complications, more functional and cosmetic outcome, and shortened operative time and hospital stay. Conclusion: The authors consider that endoscopic endonasal transsphenoidal approach provides good results with minimal invasion for patients with pituitary tumors.