• 제목/요약/키워드: Outcome Expansion

검색결과 96건 처리시간 0.026초

Use of Adaptive Meshes in Simulation of Combustion Phenomena

  • Yi, Sang-Chul;Koo, Sang-Man
    • 한국결정성장학회:학술대회논문집
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    • 한국결정성장학회 1996년도 제11차 KACG 학술발표회 Crystalline Particle Symposium (CPS)
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    • pp.285-309
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    • 1996
  • Non oxide ceramics such as nitrides of transition metals have shown significant potential for future economic impact, in diverse applications in ceramic, aerospace and electronic industries, as refractory products, abrasives and cutting tools, aircraft components, and semi-conductor substrates amid others. Combustion synthesis has become an attractive alternative to the conventional furnace technology to produce these materials cheaply, faster and at a higher level of purity. However he process os highly exothermic and manifests complex dynamics due to its strongly non-linear nature. In order to develop an understanding of this process and to study the effect of operational parameters on the final outcome, numerical modeling is necessary, which would generated essential knowledge to help scale-up the process. the model is based on a system of parabolic-hyperbolic partial differential equations representing the heat, mass and momentum conservation relations. The model also takes into account structural change due to sintering and volumetric expansion, and their effect on the transport properties of the system. The solutions of these equations exhibit steep moving spatial gradients in the form of reaction fronts, propagating in space with variable velocity, which gives rise to varying time scales. To cope with the possibility of extremely abrupt changes in the values of the solution over very short distances, adaptive mesh techniques can be applied to resolve the high activity regions by ordering grid points in appropriate places. To avoid a control volume formulation of the solution of partial differential equations, a simple orthogonal, adaptive-mesh technique is employed. This involves separate adaptation in the x and y directions. Through simple analysis and numerical examples, the adaptive mesh is shown to give significant increase in accuracy in the computations.

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Anatomical analysis of the resected roots of mandibular first molars after failed non-surgical retreatment

  • Yoon, Jiyoung;Cho, Byeong-Hoon;Bae, Jihyun;Choi, Yonghoon
    • Restorative Dentistry and Endodontics
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    • 제43권2호
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    • pp.16.1-16.9
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    • 2018
  • Objectives: Understanding the reason for an unsuccessful non-surgical endodontic treatment outcome, as well as the complex anatomy of the root canal system, is very important. This study examined the cross-sectional root canal structure of mandibular first molars confirmed to have failed non-surgical root canal treatment using digital images obtained during intentional replantation surgery, as well as the causative factors of the failed conventional endodontic treatments. Materials and Methods: This study evaluated 115 mandibular first molars. Digital photographic images of the resected surface were taken at the apical 3 mm level and examined. The discolored dentin area around the root canal was investigated by measuring the total surface area, the treated areas as determined by the endodontic filling material, and the discolored dentin area. Results: Forty 2-rooted teeth showed discolored root dentin in both the mesial and distal roots. Compared to the original filled area, significant expansion of root dentin discoloration was observed. Moreover, the mesial roots were significantly more discolored than the distal roots. Of the 115 molars, 92 had 2 roots. Among the mesial roots of the 2-rooted teeth, 95.7% of the roots had 2 canals and 79.4% had partial/complete isthmuses and/or accessory canals. Conclusions: Dentin discoloration that was not visible on periapical radiographs and cone-beam computed tomography was frequently found in mandibular first molars that failed endodontic treatment. The complex anatomy of the mesial roots of the mandibular first molars is another reason for the failure of conventional endodontic treatment.

Expandability of Cephalic Veins after Brachial Plexus Block in Arteriovenous Fistula Formation for Hemodialysis

  • Chun, Sangwook;Ryu, Jae-Wook;Ryu, Kyoung Min;Seo, Pil Won
    • Journal of Chest Surgery
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    • 제54권1호
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    • pp.31-35
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    • 2021
  • Background: Arteriovenous fistula (AVF) for hemodialysis is essential for patients with end-stage renal disease. However, it is difficult to maintain AVF reliably. It is vitally important to select proper blood vessels for AVF formation. In a previous study, a minimum diameter of 3 mm for the autologous vein was proposed. However, patients who did not meet the minimum vascular diameter before anesthesia, but fulfilled other criteria, showed satisfactory venous dilatation after brachial plexus block (BPB). This study investigated the extent of vein expansion by BPB and the surgical outcomes of dilated veins after BPB. Methods: Sixty-one patients who underwent AVF formation using an autologous vein between August 2018 and December 2019 were included in the study. The clinical characteristics of the patient groups, hemodynamic parameters including the diameter of blood vessels before and after BPB, and complications were investigated. Based on the venous diameter measured by sonography before anesthesia, patients were divided into group A (26 patients) and group B (35 patients), with venous diameters <3 mm and ≥3 mm, respectively. Results: The venous diameter expanded after anesthesia by 41% overall, by 62% in group A, and by 25% in group B. This difference between groups A and B was statistically significant (p=0.001). No other variables showed statistically significant differences. Conclusion: Sufficient venous dilatation was observed after BPB. Therefore, if the vein is sufficiently dilated after BPB, even in patients with a pre-anesthesia venous diameter <3 mm, surgery may still be performed with an expected desirable outcome.

지반의 공간적 변동성을 고려한 확률론적 해석기법에 관한 연구 (A Study on the Probabilistic Analysis Method Considering Spatial Variability of Soil Properties)

  • 조성은;박형춘
    • 한국지반공학회논문집
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    • 제24권8호
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    • pp.111-123
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    • 2008
  • 지반공학 문제는 많은 불확실한 요인을 내포한다. 이러한 불확실성 중 일부는 해석 수행과정에 필요한 지반 물성의 변동성과 관련이 있다. 본 연구에서는 지반물성의 공간적 변동성을 고려한 확률론적 해석을 수행할 수 있는 절차를 제시하였다. 제시된 방법은 유한차분 해석기법과 랜덤필드 이론을 확률론적 해석기법에 통합하게 된다. 지정된 입력 확률분포함수와 자기상관함수를 따르는 non-Gaussian 랜덤필드를 생성하기 위하여 Karhunen-$Lo{\grave{e}}ve$ 전개법을 사용하였다. 생성된 랜덤필드를 이용하여 확률론적 응답을 얻기 위해 Monte Carlo 시뮬레이션을 수행하였다. 지반의 공간적인 변동성에 기인하는 불확실성의 효과를 연구하기 위하여 대상 기초의 침하량과 지지력에 대한 일련의 해석을 수행하였다. 해석결과는 지반공학 문제에서 불확실성을 고려할 수 있는 관점을 제시하며 확률론적 평가의 결과에 미치는 지반물성의 공간적 변동성의 중요성을 보여준다.

문학 경제학 -사용가치에서 교환가치로의 전이 (Economics of Literature: Transfer of 'Worth' to 'Value')

  • 양병현
    • 영어영문학
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    • 제55권5호
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    • pp.767-792
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    • 2009
  • The two fields, economics of art and literature, tend to be put together as part of cultural economic studies; yet the former has been widely popular as compared to the latter. Economics of art has been known as part of social science which studies art economically. Similarly, economics of literature is likely to be an interdisciplinary study of literature and economics. Literature is suggested usually to reflect the economic base of a society as a form of its superstructure in view of classical Marxism; so, it is interesting to see social, economic activities, such as individual values and social institutions, income, price and opportunity cost, in a particular way of analyzing economic ideas in literature. Capital seems to have an innate property of self-expansion in literature; this property thus features actual economic life since in capitalism money is the universal value between persons and literary works. Specifically, the field of economics of literature starts with such ideas: economics of literature is part of cultural economics; and economics of literature deals with the economic value of literature. Putting interdisciplinary fields of literature and economics together, this study is to examine the economic value of literature in which Karl Marx talked about commodities with exchange value, use value, and fetishism. The exchange value is commercial worth, the actual exchange value of a publication; yet, the use value is innate worth, the aesthetic use value of literature. With commodity fetishism, profit seems not as the outcome of a social relation, but of a work- "reification" as the would-be Marxists suggest. As a commodity, the literary work appears to be able to animate life and power in reality. As a result, this paper asserts that social, economical activities in literature as we may apply to the study of economics of literature increase its economic value, implying commercial and innate worth, as the capital in the marketplace.

Exploring the Impact of Appetite Alteration on Self-Management and Malnutrition in Maintenance Hemodialysis Patients: A Mixed Methods Research Using the International Classification of Functioning, Disability and Health (ICF) Framework

  • Wonsun Hwang;Ji-hyun Lee;Se Eun Ahn;Jiewon Guak;Jieun Oh;Inwhee Park;Mi Sook Cho
    • Clinical Nutrition Research
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    • 제12권2호
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    • pp.126-137
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    • 2023
  • Hemodialysis (HD) patients face a common problem of malnutrition due to poor appetite. This study aims to verify the appetite alteration model for malnutrition in HD patients through quantitative data and the International Classification of Functioning, Disability, and Health (ICF) framework. This study uses the Mixed Method-Grounded Theory (MMGT) method to explore various factors and processes affecting malnutrition in HD patients, create a suitable treatment model, and validate it systematically by combining qualitative and quantitative data and procedures. The demographics and medical histories of 14 patients were collected. Based on the theory, the research design is based on expansion and confirmation sequence. The usefulness and cut-off points of the creatinine index (CI) guidelines for malnutrition in HD patients were linked to significant categories of GT and the domain of ICF. The retrospective CIs for 3 months revealed patients with 3 different levels of appetite status at nutrition assessment and 2 levels of uremic removal. In the same way, different levels of dry mouth, functional support, self-efficacy, and self-management were analyzed. Poor appetite, degree of dryness, and degree of taste change negatively affected CI, while self-management, uremic removal, functional support, and self-efficacy positively affected CI. This study identified and validated the essential components of appetite alteration in HD patients. These MM-GT methods can guide the selection of outcome measurements and facilitate the perspective of a holistic approach to self-management and intervention.

생쥐배아의 부화와 탈각에 미치는 Pronase의 영향 (Effect of Pronase Treatment on Mouse Embryos: Improving Hatching and Hatched Rates)

  • 문신용;최성미;김희선;류범용;오선경;서창석;김석현;최영민;김정구;최규홍;이진용
    • Clinical and Experimental Reproductive Medicine
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    • 제27권4호
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    • pp.345-351
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    • 2000
  • Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

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장래교통수요예측을 고려한 도로 유지관리 방안 (Road Maintenance Planning with Traffic Demand Forecasting)

  • 김정민;최승현;도명식;한대석
    • 한국도로학회논문집
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    • 제18권3호
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    • pp.47-57
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    • 2016
  • PURPOSES : This study aims to examine the differences between the existing traffic demand forecasting method and the traffic demand forecasting method considering future regional development plans and new road construction and expansion plans using a four-step traffic demand forecast for a more objective and sophisticated national highway maintenance. This study ultimately aims to present future pavement deterioration and budget forecasting planning based on the examination. METHODS : This study used the latest data offered by the Korea Transport Data Base (KTDB) as the basic data for demand forecast. The analysis scope was set using the Daejeon Metropolitan City's O/D and network data. This study used a traffic demand program called TransCad, and performed a traffic assignment by vehicle type through the application of a user equilibrium-based multi-class assignment technique. This study forecasted future traffic demand by verifying whether or not a realistic traffic pattern was expressed similarly by undertaking a calibration process. This study performed a life cycle cost analysis based on traffic using the forecasted future demand or existing past pattern, or by assuming the constant traffic demand. The maintenance criteria were decided according to equivalent single axle loads (ESAL). The maintenance period in the concerned section was calculated in this study. This study also computed the maintenance costs using a construction method by applying the maintenance criteria considering the ESAL. The road user costs were calculated by using the user cost calculation logic applied to the Korean Pavement Management System, which is the existing study outcome. RESULTS : This study ascertained that the increase and decrease of traffic occurred in the concerned section according to the future development plans. Furthermore, there were differences from demand forecasting that did not consider the development plans. Realistic and accurate demand forecasting supported an optimized decision making that efficiently assigns maintenance costs, and can be used as very important basic information for maintenance decision making. CONCLUSIONS : Therefore, decision making for a more efficient and sophisticated road management than the method assuming future traffic can be expected to be the same as the existing pattern or steady traffic demand. The reflection of a reliable forecasting of the future traffic demand to life cycle cost analysis (LCCA) can be a very vital factor because many studies are generally performed without considering the future traffic demand or with an analysis through setting a scenario upon LCCA within a pavement management system.

문화재 활용 사업 모니터링 및 평가 - 2016년 살아 숨 쉬는 향교·서원 만들기 사업을 중심으로 - (A Monitoring and Evaluation on the Project for Utilization of Cultural Property - Focused on the Project "Living and Breathing Hyanggyo·Seowon" in 2016 -)

  • 박동석
    • 한국전통조경학회지
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    • 제35권3호
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    • pp.94-104
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    • 2017
  • 본 연구는 문화재청이 2016년도에 지역문화재 활용사업으로 추진하는 살아 숨 쉬는 향교 서원문화재 만들기 사업의 예산지원을 받은 전국 77개 향교 서원문화재 활용 사업을 대상으로 문화재 활용에 대한 이해를 갖고 있는 전문 인력을 중심으로 전문가 현장평가 및 컨설팅과 일반인 모니터링 그리고 관람객 만족도 조사를 진행하였다. 이에 사업의 계획 운영 실적 성과 연차별 특별지표 부문에 종합평가는 모두 양호 수준으로 나타났다. 사업의 종합적인 성과 중 우수한 점으로는 첫째, 지역의 문화재 향유권 신장, 둘째, 지역 내 문화재 활용 인적 네트워크 확대, 셋째, 지역 내 커뮤니티 공간으로 활용, 넷째, 자유학기제 연계 사업을 통한 문화재 활용 교육콘텐츠의 다양화 등이 있었다. 반면 미흡한 점으로는 첫째, 프로그램 품질 저하, 둘째, 사업계획 대비 실행 부족, 셋째, 지자체의 관심 및 참여 미흡, 넷째, 홍보부족, 다섯째, 자유학기제의 경우 지역 문화재 특성이 반영된 교육콘텐츠 부족 등이 있었다. 사업의 발전 방안으로는 첫째, 향교 서원문화재의 특성을 살린 프로그램 개발, 둘째, 외국인 대상 프로그램 개발, 셋째, 전문 인력 양성, 넷째, 홍보 확대, 다섯째, 새로운 강의 기법 개발, 여섯째, 지역 내 열린 공간으로 활용, 일곱째, 공간별 활용 계획, 여덟째, 평가제도 개선, 아홉째, 관람객 의견 반영 강화, 열 번째, 사업별 집중 컨설팅을 제안하였다.

학교급식의 관리와 효과에 대한 초등교사들의 태도 분석 (Analysis of Elementary School Teachers' Attitude Toward School Food Service Management and Effect)

  • 김학현
    • 한국학교ㆍ지역보건교육학회지
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    • 제1권1호
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    • pp.61-82
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    • 2000
  • The purpose of this study was to find out the general problems of school food service and to explore a way to improve it, by examining elementary school teacher's consciousness and attitude toward it that gave a big impact on children's development of food habit. For attaining the purpose, the following research questions were posed : 1) What's elementary school teacher attitude toward school food service management? 2) What's elementary school teacher attitude toward school food service effect on children? 3) What's elementary school teacher opinion about how to develop school food service? The subjects of study were 328 male or female teachers who served at elementary school in urban and rural area, including eup, myon, or farming and fishing villages, Kyonggi province. A questionnaire survey was conducted over them. The conclusions were as follows: 1) Teacher Attitude Toward School Food Service Management Concerning food service place, the subjects were more satisfied at food service room(73.3%) than at classroom(23.0%). They responded that food service room was more effective, than classroom, for food transportation, distribution and post-arrangement. Their satisfaction at food service place was significantly different. The older teachers considered personnel management and cooking room's sanitary management to be more efficient, and their age made a significant difference to their consciousness of these things. Many teachers(63.1%) thought the measures to prevent and manage group food poisoning were relatively efficient. The male teachers expressed more affirmative view on the efficiency of school food expense management and menu preparation than female teachers, and there was a significant disparity between male and female teachers. 2) Elementary School Food Service Effect School food service was thought to be very effective for physical growth(74.1%) and physical strength improvement(70.1%). Teachers at smaller school revealed more affirmative response toward school food service effect on correcting an unbalanced diet, and older teachers considered its effect on nutrition knowledge acquisition and learning outcome to be more great. Teachers at larger school put less value on its effect on table manners, and school size produced a significant difference. The number of teachers who thought school food service generally raised parent concern and support for school(36.6%) was a little more than that of teachers who didn't think so(15.2%). And the number of teachers who didn't consider its effect on improving parent food life to be good(29.3%) was slightly more than that of teachers who did. 3) School Food Service Reform Measure What's most urgently needed for better school food service management appeared to be an expansion of facilities concerned, followed by more effective food distribution and transport, cooking room's better sanitary management, more successful food poisoning prevention and management, more effective food expense management, and an increase of food service personnel in the order named. The most effective means of school food service education was found to be a creation of link system to family, followed by a development of school food service education program, a development of teaching materials, an insertion of school food service in curriculum, and teacher education in the order named.

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