• 제목/요약/키워드: second-order expansion

검색결과 323건 처리시간 0.028초

Research on the calculation method of sensitivity coefficients of reactor power to material density based on Monte Carlo perturbation theory

  • Wu Wang;Kaiwen Li;Yuchuan Guo;Conglong Jia;Zeguang Li;Kan Wang
    • Nuclear Engineering and Technology
    • /
    • 제55권12호
    • /
    • pp.4685-4694
    • /
    • 2023
  • The ability to calculate the material density sensitivity coefficients of power with respect to the material density has broad application prospects for accelerating Monte Carlo-Thermal Hydraulics iterations. The second-order material density sensitivity coefficients for the general Monte Carlo score have been derived based on the differential operator sampling method in this paper, and the calculation of the sensitivity coefficients of cell power scores with respect to the material density has been realized in continuous-energy Monte Carlo code RMC. Based on the power-density sensitivity coefficients, the sensitivity coefficients of power scores to some other physical quantities, such as power-boron concentration coefficients and power-temperature coefficients considering only the thermal expansion, were subsequently calculated. The effectiveness of the proposed method is demonstrated in the power-density coefficients problems of the pressurized water reactor (PWR) moderator and the heat pipe reactor (HPR) reflectors. The calculations were carried out using RMC and the ENDF/B-VII.1 neutron nuclear data. It is shown that the calculated sensitivity coefficients can be used to predict the power scores accurately over a wide range of boron concentration of the PWR moderator and a wide range of temperature of HPR reflectors.

A Study on Korean Male Cosmetics Analysed Through The Newspaper Articles From 2000 To 2010

  • An, Jin-Kyung;Hong, Na-Young
    • International Journal of Costume and Fashion
    • /
    • 제11권1호
    • /
    • pp.63-83
    • /
    • 2011
  • This study aims to prove the changes, development and social background of Korean male cosmetics over the period of 2000-2010. There were total 574 articles written about male make-up and cosmetics in Chosun Daily, Joongang Daily and Donga Daily, which are the top three Korean local daily newspapers in terms of sales revenue for that period. These articles were analyzed together with social background research from various books and daily newspapers. The analysis of articles was divided into different categories; such as foundation cosmetics, color cosmetics, hair, and the social background. It was found that the articles related to foundation cosmetics were written the most, the articles related to male appearance management were second, articles on other items including how to manage the skin being the least. As for the social background of Korean male cosmetics, first of all, a change in social recognition can be pointed out. The traditional understanding of gender roles has changed, men's appearance management has started to be regarded as a competitive talent, and at the same time, the esthetic viewpoint for men also has changed. One example is the newly made popular term, "flower-handsome man", which shows the new trend of favoring males with nice skin. Second, the expansion of mass culture can be pointed out. As consumers can get information and fashion trends easier and faster, the fashion spreads fast, and this has led to the generalization and popularization of the sense of beauty. Third, the development of scientific technology and medical science can be pointed out. Thanks to the progress in those areas. the extension of youthfulness has become possible and the cosmetics industry was also affected greatly, as shown in the market spread of functional products for anti-ageing and wrinkle control as the interest in anti-ageing has grown. There are benefits from the development of scientific technology, but the problem of environmental pollution has appeared due to machinery and industrialization and thus the issue of well-being has been raised. Rising interest in naturalism, pro-environmentalism and organic cosmetics has influenced the cosmetics industry. In addition, the quantity of ultraviolet rays exposed to our skin has increased due to the air pollution caused by the destruction of environment, leading to increased usage of sun block lotion. Lastly, the influence of consumer society and the expansion of consumerism culture can be pointed out. In the modern society, consumption acts not only as the use of products and services but it also has an important role of mediating individuals with others and the society. The market for male cosmetics has been expanding and the number of men putting on make-up has been increasing rapidly. Therefore, this study is meaningful in that the analysis of the mode of change and the social background are an essential process in order to provide a direction for the future market for male cosmetics.

Alumina와 zirconia가 치과용 코아 도재의 물리적 성질에 미치는 영향에 관한 실험적 연구 (AN EXPERIMENTAL STUDY OF THE EFFECT OF ALUMINA AND ZIRCONIA ON MECHANICAL PROPERTIES OF DENTAL CORE PORCELAIN)

  • 신현수;이상진;이근우
    • 대한치과보철학회지
    • /
    • 제31권3호
    • /
    • pp.317-349
    • /
    • 1993
  • This study investigated the effect of filler particle size and weight% on mechanical properties of dental core porcelain. In alumina, variation in particle size and weight% and in zirconia, variation in weight%, all specimens were tested three-point bending strength, transmittance, thermal expansion coefficient, porosity and shrinkage and observed with SEM and analysed with X-ray diffractometer. In order to develop shrink-free porcelain, after firing alumina only, glass wasinfiltrated. And aluminum was added to alumina with the expanding character of aluminum oxidize into alumina, and was followed by second firing of glass infiltration procedure. Then mechanical properties were observed. The results of this study were obtained as follows. 1. The bending strength of zirconia was higher than that of alumina, and $5{\mu}m$ alumina had highest strength in variation of particle size of alumina. Except for $5{\mu}m$ alumina, increased with weight%, bending strength increased up to 80% and decreased at 90%. In case of glass infiltration, bending strength was slight higher than 80% and 90% of $5{\mu}m$ alumina. 2. Transmittance increased with increase of shrinkage, decrease of porosity, and with increase of filler size and had no direct correlation with weight%. 3. Thermal expansion coefficient of alumina group was $7.42\sim8.64\times10^{-6}/^{\circ}C$ and that of zirconia group was $9.83\sim12.11\times10^{-6}/^{\circ}C$ and the latter was higher than the former. 4. In x-ray diffraction analysis, alumina group and zirconia group increased $Al_2O_3$ peak and $t-ZrO_2$ peak with increase of weight%. The second phase(cristobalite peak) was observed in zirconia 40% group. 5. Porosity of zirconia was lower than that of alumina and $5{\mu}m$ alumina group had many pores with SEM. In case of low filler content, fracture occurred in glass and high filler content, in glass and filler. In case of aluminum addition to alumina, small oxidised aluminum was observed. 6. Zirconia group had high shrinkage than alumina group, and mixed group of alumina group had high shrinkage. In case of glass infiltration, shrinkage decreased and aluminum addition to alumina group was almost shrink-free.

  • PDF

환경경영 통합 리더 프로그램의 개발과 효과에 관한 연구 (A Study on the Development and Educational Effect of the Environmental Management Integrated Leader Program)

  • 정연돈
    • 한국환경교육학회지:환경교육
    • /
    • 제10권2호
    • /
    • pp.249-268
    • /
    • 1997
  • This Study developed 'Environment Management Integrated Leader(EMIL)' program and evaluated the effect of the Program. The procedure of EMIL program development is as follows; 1) Identifying the training needs Through the interview and discussion with corporate environmental staff and research members, training need are collected. 2) Setting the training objectives 30 objectives are developed through specifying and organizing the training needs. 3) Determining the scopes of the program This program consists of the four scopes. First, the scope of Environmentally Acceptable Management is developed based on ISO 14000 and certification of environmentally friendly business. Second, the scope of Environmentally Acceptable Technology includes air pollution, water pollution, solid wasted management, and pollution prevention. Third, the scope of Integrated Environmental Management focuses on master plan, green marketing, green production, and green accounting. Finally, the scope of Integrated Environmental Concepts focuses on food pollution, environmental activities, and bio-diversity. 4) Selecting the training methods Various methods are used such as off-site visits, exercises, case study, workshop, discussion, role-playing as well as lecture. 5) Implementing the program 49 trainees participated the program for 6weeks. All trainees are working for D. Company Group. 6) Measuring training effects To evaluate the effects of the program, pre-post training evaluation method is used. The results are highly significant at all 4 scopes by the p<.01. This study has some implications in order to establish the environmental management climate. First, the development of new environmental education program for management is necessary. Second, Vast investment are required. Third, more systematic approaches are desired in environmental education. Lastly, more customized program development and implementation to fit in industries will accelerate the expansion of environmental concept.

  • PDF

우리나라 소년범(少年犯) 교정교육(稿正敎育)의 실태(實態) 문제점(問題點) (A Study of Correctional Education for Juvenile Delinquents in Korea)

  • 김경회
    • 시큐리티연구
    • /
    • 제1호
    • /
    • pp.1-16
    • /
    • 1997
  • Nowdays the prison is the only correctional for juvenile delinquents not to be the second offenders in Korea. Originally the correctional education aims to let criminals go back to the society as a decent citizen after correcting them and prevent them from comminitting crimes repeatedly. Being considered to increase the second offenders in juvenile delinquency, the purpose of this study is to investigate the actual condition and problems of juvenile correctional education in Korea and to find out the solution of problems. First of all, this study examines the actual condition of the juvenile delinquency in Korea. The number of juvenile crimes has been increased from 1985 to 1995. In 1997, the current education in correctinal institutions for juvenile delinquents is inferior to that of developed countries. On the basis of this investigation, improvement plans which will be fit for the circumstances in Korea are suggested. The conclusion of this study are summarized as follows 1. Correctional institutions will be improved to accommodate the proper number of convicts. 2. Correctional officers should be qualified proffessinals who can achieve the aim of correctional education successfully. 3. In order to cultivate he social adaptability of convicts, the expansion of open prison is needed. 4. It is neccessary to classify convicts by means of moderized and scientific methods. 5. Correctinal education consist of various practical courses on jobs, After complenting these vocatinal training, the convict can obtain certificates. 6. The government has to has to plan policies that the released convicts can get jobs for living. 7. Owing to keeping prisons sanitary, it is very helpful for convicts to have thebelief that they are not abandoned by the member of their society. 8. Convicts are given opportunities to participate religious activities by their free-will. If above improvement plans are sufficiently accomplished, correctinal education will obtain good results, It is also effective to minimize the repetition of offence by ex-convicts.

  • PDF

목질 바이오매스의 활용에 대한 동향 분석 - 목질 바이오매스의 생산·공급, 그리고 활용을 중심으로 - (Analysis on the Trend of the Utilization of Woody Biomass - Production, supply, and practical use of woody biomass -)

  • 안병일;김철환;이지영;심성웅;조후승;이경선;이지영
    • 펄프종이기술
    • /
    • 제44권4호
    • /
    • pp.32-42
    • /
    • 2012
  • Wood biomass including forest residues, waste wood, and construction residuals has been widely generated in Korea, but forest biomass from the National Forest Management Operation Project plays a big role in generating wood biomass. Unfortunately the promotion policy of woody energy organized by the Forest Service in Korea concentrates more on demand creation rather than on supply expansion. Therefore, in order to utilize insufficient wood resources effectively, it is greatly required to develop uses for maximizing their added value. In particular, more attention to the use of the second generation biomass has been paid in foreign countries because there is a threshold that the first generation biomass cannot produce enough biofuel without threatening food supplies and biodiversity. In Korea, wood pellets are regarded as the alternative clean fuels to oils and coals that emit green house gases into the atmosphere. However, using wood as pellet raw materials can not be an economic way because the value of wood disappears right after burning in the boiler in spite of its contribution to the decrease of carbon emission. Differently from wood pellets, kraft pulping process using woody biomass produces black liquor as a by-product which can be used to generate electricity, bioenergy and biochemicals through gasification. Thus, it can be more economical to make a torrefaction of lignocellulosic biomass such as low-quality wood and agricultural leftovers as raw materials of pellets.

전국민 의료보험 실시에 따른 사회전체 순편익 분석 (Economic Benefits of Implementing National Health Insurance by Measurement of Changes in the Consumer's Surplus)

  • 김한중;이해종
    • Journal of Preventive Medicine and Public Health
    • /
    • 제22권3호
    • /
    • pp.398-405
    • /
    • 1989
  • A change in the consumer's surplus was measured in order to evaluate the social benefit to be derived from expanding health insurance to the entire population. The most refined and correct way to measure a project's net benefit to society is to determine a change in the consumer's surplus. Benefits from introducing the health insurance program to the uninsured people can be classified into two elements. The first is the pricing-down effect(E1) which results from applying the insurance price system, which is lower than the actual price, to the uninsured patients. The second effect(E2) is a decrease in actual payment because an insured patient pays only a portion of the total medical bill(copayment). We collected medical price information from the data banks of 93 hospitals, and obtained information of medical utilization by referring to the results of other research and from data published by the Korean Medical Insurance Societies. The total net benefit was estimated as \214 billion, comprising the first effect(E1) of \57 billion and the second effect(E2) of \157 billion. The price elasticity of physician visits is less than that of hospital admissions: however, benefits from the increase in physician visits are greater than those from hospital admissions because there are considerably more of physician visits than hospital admissions. The sensitivity analysis also shows the conclusion that expansion of the health insurance program to the entire population would result in a positive net benefit. Therfore, we conclude that the National Health Insurance Program is socially desirable.

  • PDF

풍력발전기를 포함하는 전력계통에서의 신뢰도 기반 HVDC 확충계획 (Probabilistic Reliability Based HVDC Expansion Planning of Power System Including Wind Turbine Generators)

  • 오웅진;이연찬;최재석;윤용범;김찬기;임진택
    • 전기학회논문지
    • /
    • 제67권1호
    • /
    • pp.8-15
    • /
    • 2018
  • New methodology for probabilistic reliability based grid expansion planning of HVDC in power system including Wind Turbine Generators(WTG) is developed in this paper. This problem is focused on scenario based optimal selection technique to decide best connection bus of new transmission lines of HVDC in view point of adequacy reliability in power system including WTG. This requires two kinds of modeling and simulation for reliability evaluation. One is how is reliability evaluation model and simulation of WTG. Another is to develop a failure model of HVDC. First, reliability evaluation of power system including WTG needs multi-state simulation methodology because of intermittent characteristics of wind speed and nonlinear generation curve of WTG. Reliability methodology of power system including WTG has already been developed with considering multi-state simulation over the years in the world. The multi-state model already developed by authors is used for WTG reliability simulation in this study. Second, the power system including HVDC includes AC/DC converter and DC/AC inverter substation. The substation is composed of a lot of thyristor devices, in which devices have possibility of failure occurrence in potential. Failure model of AC/DC converter and DC/AC inverter substation in order to simulate HVDC reliability is newly proposed in this paper. Furthermore, this problem should be formulated in hierarchical level II(HLII) reliability evaluation because of best bus choice problem for connecting new HVDC and transmission lines consideration. HLII reliability simulation technique is not simple but difficult and complex. CmRel program, which is adequacy reliability evaluation program developed by authors, is extended and developed for this study. Using proposed method, new HVDC connected bus point is able to be decided at best reliability level successfully. Methodology proposed in this paper is applied to small sized model power system.

Adaptable Center Detection of a Laser Line with a Normalization Approach using Hessian-matrix Eigenvalues

  • Xu, Guan;Sun, Lina;Li, Xiaotao;Su, Jian;Hao, Zhaobing;Lu, Xue
    • Journal of the Optical Society of Korea
    • /
    • 제18권4호
    • /
    • pp.317-329
    • /
    • 2014
  • In vision measurement systems based on structured light, the key point of detection precision is to determine accurately the central position of the projected laser line in the image. The purpose of this research is to extract laser line centers based on a decision function generated to distinguish the real centers from candidate points with a high recognition rate. First, preprocessing of an image adopting a difference image method is conducted to realize image segmentation of the laser line. Second, the feature points in an integral pixel level are selected as the initiating light line centers by the eigenvalues of the Hessian matrix. Third, according to the light intensity distribution of a laser line obeying a Gaussian distribution in transverse section and a constant distribution in longitudinal section, a normalized model of Hessian matrix eigenvalues for the candidate centers of the laser line is presented to balance reasonably the two eigenvalues that indicate the variation tendencies of the second-order partial derivatives of the Gaussian function and constant function, respectively. The proposed model integrates a Gaussian recognition function and a sinusoidal recognition function. The Gaussian recognition function estimates the characteristic that one eigenvalue approaches zero, and enhances the sensitivity of the decision function to that characteristic, which corresponds to the longitudinal direction of the laser line. The sinusoidal recognition function evaluates the feature that the other eigenvalue is negative with a large absolute value, making the decision function more sensitive to that feature, which is related to the transverse direction of the laser line. In the proposed model the decision function is weighted for higher values to the real centers synthetically, considering the properties in the longitudinal and transverse directions of the laser line. Moreover, this method provides a decision value from 0 to 1 for arbitrary candidate centers, which yields a normalized measure for different laser lines in different images. The normalized results of pixels close to 1 are determined to be the real centers by progressive scanning of the image columns. Finally, the zero point of a second-order Taylor expansion in the eigenvector's direction is employed to refine further the extraction results of the central points at the subpixel level. The experimental results show that the method based on this normalization model accurately extracts the coordinates of laser line centers and obtains a higher recognition rate in two group experiments.

LRM 노멘을 수용하기 위한 전거제어시 고려사항에 관한 연구 (A Study on Considerations in the Authority Control to Accommodate LRM Nomen)

  • 이미화
    • 한국도서관정보학회지
    • /
    • 제52권1호
    • /
    • pp.109-128
    • /
    • 2021
  • 본고에서는 LRM 노멘 개체를 수용하기 위한 전거제어시 고려사항을 모색하고자 문헌연구, RDA 규칙분석, 국내 목록 전문가 의견조사를 실시하였다. 그 결과 전거제어를 위해 노멘의 속성 요소, 목록기술, MARC 전거포맷 측면에서 고려사항을 제안하였다. 첫째, 노멘의 속성으로 LRM 노멘의 유형, 스킴, 이용대상자, 이용맥락, 참고정보원, 언어, 문자, 문자변환과 RDA에서 추가한 식별상태, 주기, 구분불가한 이름지시자의 기술을 가능한 상세히 기술해야 한다. 둘째, 노멘의 속성요소 및 관계요소를 기술하기 위해 목록규칙인 RDA에 제시된 대로 비구조화, 구조화, 식별자, IRI로 기술하며, 이중 구조화된 기술을 위해서는 어휘인코딩스킴(VES), 스트링인코딩스킴(SES)이 작성되어야 한다. 또한, 전거형접근점에 대한 구조 및 우선 이름/표제에 대한 목록 규칙도 마련되어야 한다. 셋째, LRM 노멘을 반영할 수 있도록 MARC 21 전거포맷을 마련하기 위해 Maxwell의 확장(안)을 바탕으로 추가 확장 방안을 제안하였다. (1) 노멘 마다 속성이 입력될 수 있도록 4XX, 5XX에 속성이 기술되어야 하며, 1XX, 5XX와 4XX에 기술될 노멘의 속성을 구분하였다. (2) 노멘 속성으로 유형, 언어, 문자, 문자변환, 이용맥락, 유효기간을 기술하기 위해서는 MARC 21내에 표시기호 및 식별기호가 추가되어야 한다. 이에 368, 381, 377의 식별기호 확장과 이용맥락과 유효기간을 기술하기 위한 표시기호를 추가할 것을 제안하였다. 본고에서 제안한 LRM 노멘을 위한 전거제어시 고려사항은 국내에서 LRM을 반영한 전거제어 방안을 마련하는 기반이 될 것이다.