• Title/Summary/Keyword: Changes

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FAULT-TREE-BASED RISK ASSESSMENT FOR DYNAMIC CONDITION CHANGES

  • Kang, Hyun-Gook;Jang, Seung-Cheol
    • Nuclear Engineering and Technology
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    • v.39 no.2
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    • pp.123-128
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    • 2007
  • In order to apply a static fault-tree (FT) method to a system or a plant whose configuration changes dynamically, condition gates and a post processing method are used to effectively accommodate these changes. An operator's performance change, which can be caused by these configuration changes, should also be considered to assess the risk to a plant in a more realistic manner. This study aims to develop an integrated framework to accommodate various configuration changes and their effect on an operator’s performance by using the FT model. We applied a condition-based human reliability assessment (CBHRA) method to consider various conditions endured by an operator. That is, we integrated the CBHRA method with the conventional post processing method for modeling the system configuration changes. The effect of the condition monitoring systems installed in a plant is also considered. In this study, we show an example application of the integrated framework to a probabilistic safety assessment for the shutdown phase of a nuclear power plant.

Clinical importance of TMJ Osteoarthritis in Dental Practice (임상가를 위한 특집 3 - 치과진료에서 악관절 골관절염의 중요성)

  • Tae, Ilho;Song, Yunheon;Kim, Youn Joong
    • The Journal of the Korean dental association
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    • v.51 no.2
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    • pp.92-98
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    • 2013
  • Osteoarthritis is one of the most common degenerative disease in the temporomandibular joints(TMJ). Structural changes in the osseous structure is associated with destructive changes such as erosion, flattening and other bony changes. Destructive degenerative changes quite often cause shortening of the condyles which eventually produces the changes in the occulsion and the facial profile which require orthorgnathic surgery and/or orthodontic treatment by the dental professional. The dentists need to understand the nature and the pathophysiology of the osteoarthritis in the TMJ for the better dental treatment, especially in orthodontic and prosthodontic treatment. The possibility of serious complication can not be avoided after any dental treatment is given to the patient if osteoarthritic changes in the TMJ is under progression as undiscovered.

A Study on the Changes of the Suburban Rural Houses. - focusing on the Houses in Samga 3 Ri, YongIn-Gun, KyungKi-Do - (도시근교 농촌주택의 변화에 관한 연구 -경기도 용인군 삼가3리를 중심으로 -)

  • 윤정숙;전영미
    • Korean Journal of Rural Living Science
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    • v.8 no.1
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    • pp.35-43
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    • 1997
  • The Purpose of this research was to investigate the physical changes of village, the architectural changes of houses and to find out the resident's needs of housing in suburban rural houses. Samga 3 Ri, Yong-In, KyungKi-Do was chosen for this study. The previous research, conducted in 1987 by using a field survey method, was compared with this study. 1) The study showed that the physical changes of village include an increase in the number of rooms and nonagricultural population, and variety of house types. Therefore, social intimacy, reallocation of houses according to residents' occupations, and apartments for non-agricultural population should be considered in planning village. 2) It is found that the resident's needs were to increase the number of rooms, expansion of space, and to modernize kitchin systems. The investigation on newly constructed houses indicated that residents' needs were two-story houses, changes of spaces - the number of bathrooms, private bedroom adjacent to An-bang.

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Animal Models of Alzheimer's Dementia (알쯔하이머 치매의 동물모형)

  • Woo, Sung-Il
    • Korean Journal of Biological Psychiatry
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    • v.6 no.2
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    • pp.149-152
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    • 1999
  • Transgenic mice models of Alzheimer's disease were produced by overexpressing APP(amyloid precursor protein) mutant and presenilin mutant genes using the promotors that induced neuronal expression. The neuropathologies, electrophysiological changes and behavioral changes that were demonstrated in these transgenic mice models were amyloid changes, gliotic changes, A-beta increases, deficit in LTP(long-term potentiation) and behavioral changes. Some or all of the above changes were found in each transgenic mice model. These models generally showed amyloid neuropathology but they usually lacked the neurofibrillary tangles. So, they can be regarded as partial models of Alzheimer's disease. The development of them is undoubtedly the great progress toward future research.

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통신서비스 산업의 경쟁전략 분석을 위한 진화모형

  • 이승규;손병규;최성철
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 1997.10a
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    • pp.207-210
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    • 1997
  • The drastic structural changes in telecommunications industry are imposing new strains on operators, regulators and customers. Many researchers have offered diverse frameworks for the changes from the perspectives of sociology, technology, and/or economics. However, there have been few attempts to document the competitive phenomena from management perspectives because of the technological complexities and dynamism in the fundamental transition of competition. In this study, we examine competitive environment in telecommunications industry, and identified five structural elements; telecom operator, competitors, regulation, suppliers, and customer demand. The suggested framework is used to provide a basis for explaining the changes in the characteristics of individual elements and the interactions among them. The dynamic industry-specific changes will be explained through an evolutionary model. We specify the characteristics of progressive stages and the determinants of the evolution. Changes are reviewed in terms of five criteria; regulations and competitions, value chain, technology, customers demand, and internal operations. The result of this study will be useful in analyzing and predicting industry structure and major participants' strategic behaviors and decision patterns. This study can alse be extended to other industries facing dynamic structural changes.

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Studies on Oral Toxicity of Eumcheonyijin-tang in Rats (음천이진탕의 안정성에 관한 실험적 연구)

  • 김영미;최해윤;김종대
    • The Journal of Korean Medicine
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    • v.21 no.3
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    • pp.199-208
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    • 2000
  • Objectives : In order to investigate the toxicity of rats after oral administration of Eumcheonyijin-tang extract. Methods : The experimental animals were subdivided into control, short term administration group, and long term administration group. With changes of gross appearance, the histological changes of liver and kidney were observed. Blood chemical indexes used in this study were AST, ALT, total bilirubin, albumin, BUN and creatinine in serum. Results : In the long term administration group, histological changes were detected in the liver as centrolobular disposition of fatty tissue(adipose cell), and in serum test, AST, ALT increased at 21 days after administration group, serum total bilirubin were increased 21, 28 and 35 days after administration group. So it seems to induce toxicity. Kidneys of the long term administration group revealed histological changes : increasing of connective tissue and pyknosis of glomerulus cell were observed at 28 days after administration group, and in serum test, significant changes of albumin, BUN, and creatinine were admitted. So it seems to induce toxicity. Conclusions : In long term administration of Eumcheonyijin-tang toxicity was induced.

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A Method for Engineering Change Analysis by Using OLAP (OLAP를 이용한 설계변경 분석 방법에 관한 연구)

  • Do, Namchul
    • Korean Journal of Computational Design and Engineering
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    • v.19 no.2
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    • pp.103-110
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    • 2014
  • Engineering changes are indispensable engineering and management activities for manufactures to develop competitive products and to maintain consistency of its product data. Analysis of engineering changes provides a core functionality to support decision makings for engineering change management. This study aims to develop a method for analysis of engineering changes based on On-Line Analytical Processing (OLAP), a proven database analysis technology that has been applied to various business areas. This approach automates data processing for engineering change analysis from product databases that follow an international standard for product data management (PDM), and enables analysts to analyze various aspects of engineering changes with its OLAP operations. The study consists of modeling a standard PDM database and a multidimensional data model for engineering change analysis, implementing the standard and multidimensional models with PDM and data cube systems and applying the implemented data cube to core functions of engineering change management, the evaluation and propagation of engineering changes.

Evaluation of Mandibular Condylar Bony Changes in Temporomandibular Disorders using Polytome-U Images (Polytome-U 촬영법을 이용한 측두하악관절증의 하악과두 골변화 관찰)

  • Nah Kyung-Soo
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.28 no.2
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    • pp.321-327
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    • 1998
  • The author examined bone changes from 1274 poly tomographic images of 182 temporomandibular joints which showed symptoms of temporomandibular disorder and the following results were obtained; 1. The number of temporomandibular joints which showed bone changes were 64 (35.2%) among 182 joints. 2. The age and sex distribution of 64 joints which had bone changes showed the prevalence of female (90.6%) and third decade (25.0%) followed by fourth (21.2%) and second decade (17.2%). 3. The 252 images which showed bone changes consisted of 56 images from lateral side (22.2%). 118 images from center (46.8%) and 78 images from medial side (30.9%). 4. The most frequently observed bone changes were flattening (22.7%) followed by sclerosis (19.3%) and cortical unsharpness (19.3%)

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Cardiac systolic time intervals and heather index measured by impedance cardiography during postural changes (체위변화시 심장의 수축기 시간간격 및 Heather Index의 변화)

  • 고성경;김창규;김덕원
    • Journal of the Ergonomics Society of Korea
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    • v.11 no.1
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    • pp.67-79
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    • 1992
  • Cardiac systolic time intervals (STLs) and Heather index (HI) were used to access changes in left ventricular function of six male subjects exposed to postural changes,$0^{\circ}C$, ${\pm}2^{\circ}C$, ${\pm}45^{\circ}C$, ${\pm}90^{\circ}C$, Significant prolongation of the pre-ejection period (PEP) and PEP/ LVET ratio, shortening of the left ventricular ejection time (LVET), STI, HI and $1/PEP^{2}$were observed during exposure to both $+45^{\circ}C $ and $+90^{\circ}C $But the values measured during $-45^{\circ}C $ and$-90^{\circ}C $ were reversed. Changes in fluid shift, filling volume, preload, after load and sympathetic activities may account for the observed findings. Early response of cardiac foctions was recorded using impedance cardiography. This method is very simple but accurate. Thus it will be useful in this aerospace and work physiology. In conclusion, STIs appear to provide reliable noninvasive method for examining changes of cardiac function during exposure to postural changes.

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A Study on the Effects of Meditative Respiration Training on the Changes of Stress Hormones (명상호흡 수련이 스트레스성 호르몬에 미치는 영향에 관한 연구)

  • Park, Sang-Kyu
    • The Korean Journal of Emergency Medical Services
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    • v.8 no.1
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    • pp.47-55
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    • 2004
  • The purpose of this study were to investigate the effect of meditative respiration training for 6weeks on the changes of ACTH and Cortisol which are stress hormones in 10 male workers. The results of this study were as follows : 1. After meditative respiration training for 6weeks, the changes of heart rate, respiratory rate, SBP, DBP were slightly decreased. 2. After meditative respiration training for 6weeks, the changes of ACTH hormone were significantly decreased(p<.01). 3. After meditative respiration training for 6weeks, the changes of cortisol hormone were significantly decreased(p<.05). The above conclusions suggested that short-term meditative respiration training was an effective training method to changes mental emotional states and physiological stress hormone level affirmatively. Further, the future researches must analyze the physiological and psychological characteristics affecting mental health synthetically and develop meditative respiration program suitable to the various items and classes, especially EMT.

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