• Title/Summary/Keyword: equation of higher degree

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A Study on the Use of Hierarchical Elements for Incompressible Flow Computations (비압축성 유동계산을 위한 계층 요소 사용에 대한 연구)

  • Kim, Jin-Whan
    • Proceedings of the KSME Conference
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    • 2001.06e
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    • pp.422-429
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    • 2001
  • A two dimensional hierarchical elements are investigated for a use on the incompressible flow computation. The construction of hierarchical elements are explained through the tensor product of 1-D hierarchical functions, and a systematic treatment of essential boundary values has been developed for the degrees of freedom corresponding to higher order terms. The numerical study for the poisson problem showed that the present scheme can increase the convergence and accuracy of finite element solutions, and can be more efficient than the standard first order with many elements. Also, for Stokes and cavity flow cases, solutions from hierarchical elements showed better resolutions and future promises for higher order solutions.

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Development of Structural Equation Model for Causal Relationships Among the Risk Factors of Arteriosclerosis (동맥경화증 위험요인들간의 인과관계에 대한 구조모형 구축)

  • 오현수;서화숙
    • Journal of Korean Academy of Nursing
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    • v.29 no.6
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    • pp.1192-1207
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    • 1999
  • The purpose of this study was to clarify the dynamic relationships among risk factors of arteriosclerosis and to develop and examine a model which could explain this relationship clearly. Data were collected from medical records of 400 male clients who visited a university hospital located in Inchon for physical examinations, from May 1996 to December 1996. Data were analyzed using the LISREL (Linear Structural Relationship) 8 program. To test the fitness of the hypothesized model, chi-square, RMSR (root mean square residual), GFI (goodness of fit index), CN (critical number) and Q-plot were used. Most of the fitness measurements, except the chi-square showed that the hypothesized model complimented the real data. According to the results, there were trends that obesity and hyperlipidemia were prevalent in heavier smokers, higher alcohol intakers, and groups who excercised less. Also, hypertension was more prevalent in older age, higher alcohol intaker, and higher serum lipid level groups. In contrast to the hypothesis, alcohol intake did not significantly affect serum lipid levels. This might be due to the serum lipid measurements (total cholesterol and trigryceride) used in this study to estimate hyperlipidemia. The direct effect of smoking on hypertension was not significant. However, the total effect of smoking on the hypertension was significant since indirect effects of smoking on hypertension, such as obesity and hyperlipidemia, were significant. The total effect of obesity on hypertension was significant since the indirect effect of obesity on hypertension via hyperlipidemia was significant, although the direct effect of smoking on hypertension was not significant. The degree of explaining hyperlipidemia with smoking, exercise, and obesity was high (60%), however, the degree of explaining obesity with age, smoking, alcohol intake, and exercise was very low (7%). On the basis of these results, high risk factors of arteriosclerosis such as hypertension, hyperlipidemia, or obesity are either directly or indirectly correlated each other. Therefore, it is difficult to predict outcomes for increasing or decreasing the risk factors by simply modulating a factor. Smoking, alcohol, and exercise both directly and indirectly affected major risk factors of arteriosclerosis. Therefore, correcting these variables is required to decrease risk factors. Finally, the relationship among other risk factors which have been known to be related with arteriosclerosis (diet, stress or hereditary) should be clarified in further studies.

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Clinical study on the improvement degree of Bell's palsy with DITI (DITI를 이용한 안면신경마비환자의 호전도에 대한 임상적 고찰)

  • Sung, Byung-Gon;Park, Min-Chul;Lim, Kyu-Sang
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.13 no.2
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    • pp.190-199
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    • 2000
  • We had studied the relationship between the difference of average temperature of Meridian points of left and right face taken by DITI on 1st hospital day and the improvement degree of facial mucles on the patients of Bell's palsy after 10 days treatment. The clinical data and thermographic imaging were analyzed on the 42 cases of Bell's palsy who were treated in the Chunju Oriental Medicine Hospital of Wonkwang University from May to November 1999, and we selected 29 cases within 10 day-onset and the following results were obtained. 1. Assuming the difference of the muscle scores' sums very attending day from after 10 days treatment is improvement degree, and presuming the improvement degree is y, and the mean difference of average temperature between normal and abnormal facial side is x, we can infer the equation of the first degree as following [ y = 2.62 + 2.16 x ]. 2. This means that the higher temperature of nerve falsy side than normal side, the better consequence of treatment we can obtain.

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Development of Multi-body Dynamics Analysis Program with Constraints using CFEM (CFEM을 이용한 구속조건이 있는 다물체 운동해석 프로그램 개발)

  • Park, Sun-Ho;Lee, Seung-Soo
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.40 no.2
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    • pp.101-107
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    • 2012
  • In this study, Constraint Force Equation Methodology (CFEM) is used to develop a multi-body dynamic analysis program with constraints. Seven constraint models are implemented to analyze constraint motions of multiple bodies. The augmented equations with the constraints are solved with the 4th order Runge-Kutta method for higher degree of accuracy. The analysis code is verified by comparing the analysis results of the motion of bodies with various constraints to published results.

Ductility Demand of Precast Coupled Shear Wall (프리캐스트 병렬 전단벽의 연성도 해석)

  • 홍성걸;김영욱
    • Journal of the Earthquake Engineering Society of Korea
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    • v.3 no.2
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    • pp.29-40
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    • 1999
  • This study presents a simplifled calculation method for required ductility of coupling beams in precast coupled shear walls at preliminary seismic design stages. Deflection of precast coupled shear walls based on a continuum approach is combined with inelastic gap opening of horizontal connection of panels to provide a relationship between the system-level ductility and the element-level ductility in a precast coupled shear wall. The equation proposed herein for ductility requirement for coupling beams shows that higher stiffness and lower strength of coupling beams result in high ductility reuqirement. The equation also shows that the ductility requirement is proportional to the degree of gap opening of the story in question. However, the coupling beam ductility in higher stories are not affected by gap openings of horizontal connections of panel.

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A Study on Cable Lifetime Evaluation Based on Characteristic Analysis of Insulation Resistance by Acceleration Factor of the Arrhenius Equation (아레니우스 방정식의 가속인자를 만족하는 절연저항특성 분석에 의한 케이블 수명평가 연구)

  • Um, Kee-Hong;Lee, Kwan-Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.5
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    • pp.231-236
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    • 2014
  • With the development of industry these days, the demand for electric power increases and the larger capacity for power transfer is required. The scales of facilities should become larger; and the relative systems are required to operate with a higher degree of reliability. Therefore, stabilization of electric power systems is an important issue. The high degree of reliability required in the process of production and supply of electric power is an essential part of industrial society. Accident such as blackouts causes a hugh amount of economic losses to the high-tech industrial society dependent upon electric power. In this paper, in order to determine a stable operation of high-voltage power cable, used as a unique means of delivering electric power generated at a power station, we figure out the time rate of change of insulation resistance following a decay accelerating factor Arrhenius equation. With the data from the insulation resistance, we can determine the lifetime of power cable in operation.

Spirituality's Impact on Posttraumatic Interpersonal Relation Regarding the Distribution of Negative Affect (부정적 정서 유통에 따른 대인관계 문제의 영성효과: 트라우마를 중심으로)

  • LEE, Eunsung;CHOI, Choongik
    • Journal of Distribution Science
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    • v.17 no.5
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    • pp.103-111
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    • 2019
  • Purpose - This paper aims to examine a spirituality's impact on the posttraumatic interpersonal relationships of family violence with a structural equation model(SEM). This article starts with the research idea that family violence experience bring about negative emotion in terms of interpersonal relationship leading to the distribution of negative affect in social relationship. The research question of this study pinpoints on how family violence experience affects interpersonal relationship problems and how spirituality affects interpersonal relations problems. Based on the idea, we attempts to deal with spirituality's impact as a driving factor of transforming the distribution of negative affect. Research design, data, and methodology - The structural equation modelling(SEM) is employed as a analysis method of this study. SEM provides a chiefly cross-sectional statistical modelling method, and moreover it allows multiple variables to be associated with a latent variable in this analysis. 300 samples from Seoul, Gyeonggy and Gangwon are selected in the survey. We chose available 271 among them. Results - The results verify that trauma have placed an negative impact on personal relations. The study results also shows that the more serious get the degree of family violence trauma, the worse become interpersonal relationship problems. What is more interesting is that the degree of trauma's impact on interpersonal relation problems in male is higher than that of trauma's impact in female. It is mainly attributed to the fact that women are superior to men in terms of empathy ability and interpersonal relationship orientation. It can be noted that the well-managed spirituality will be able to make a great contribution towards reducing the degree of trauma caused by interpersonal relationships. Conclusions - The study results demonstrates that family violence have negative impacts on spirituality, while spirituality have an positive impacts on reduction the problems of interpersonal relationship. It has been found out that family violence trauma may cause negative affectivity in personal relations, which can distribute negative impacts regarding interpersonal relationship in society. This study also supports that spirituality will be able to function well as a helper, which may reduce the distribution of negative affect in society.

An Investigation of the Use of Hierarchical Elements for Incompressible Flow Computations (비압축성 유동계산을 위한 계층 요소 사용의 검토)

  • Kim, Jin-Hwan;Jeong, Chang-Ryul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.26 no.9
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    • pp.1209-1217
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    • 2002
  • The use of a two dimensional hierarchical elements are investigated for the incompressible flow computation. The construction of hierarchical elements are explained by both a geometric configuration and a determination of degrees of freedom. Also a systematic treatment of essential boundary values has been developed for the degrees of freedom corresponding to higher order terms. The numerical study for the poisson problem shows that the computation with hierarchical higher order elements can increase the convergence rate and accuracy of finite element solutions in more efficient manner than the use of standard first order element. for Stokes and Cavity flow cases, a mixed version of penalty function approach has been introduced in connection with the hierarchical elements. Solutions from hierarchical elements showed better resolutions with consistent trends in both mesh shapes and the order of elements.

A study on the settlement of earth dam by the changes of the density (흙댐의 밀도변화에 의한 압밀침하에 대한 연구)

  • 윤충섭
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.28 no.3
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    • pp.89-98
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    • 1986
  • This study was carried out for the settlement and camber of earth dam by the changes of the density. The testing material was taken five kinds of Soil used as banking material and it was compacted by 100, 95, 90, 85 and 80% compaction degree. The results of the settlement of earth dam whose height ranges from 10m to 50m are as follows. 1.The more the fine particle (n) increases, the higher the liquid limit (WL) and the lower the dry density (rd) becomes as follows; rd=2. 22-0. 0052n (gr/cm$_3$) rd=2. 394-0. 0164WL rd=2. 185-(5. 8n-2. 5WL)X10-$_3$ 2. The higher the optimum moisture content (Wo) becomes, the lower the density becomes as follows; rt,=2. 68-0. 028Wo rd=2. 578-0. 04Wo 3. 3.Most of the consolidation occurs immediately by loading and the more the fine particle increases, the lower the coefficient of consolidation becomes. 4.The more the fine particle increases and lower the compaction degree (D) becomes,the lower the pre-consolidation load (Pc) becomes but on the contrary the compression index (Cc) becomes higher. Those equation is as follows. Pc=3. 32-(4. 3n-3. 0D) X10-2 (kg/cm$^2$) Cc=0. 41+(1. 33n-4. 44D) X10-$^3$ 5.The more the consolidation load (P) increases, the lower the coefficient of volume change (mv) becomes with mv=ap-b, the higher the consolidation ratio (u) becomes with U= (0. 6~1. 35)PO.4 6.The more the fine particle (n) increases, the more the settlement of dam occurs with U=anb and 60-80% of the settlement occurs under construction. 7.The camber of dam has higher value in condition that has more fine particle, poorer compaction and higher height of dam. In the dam construction about twice value of table 7 is required for dam safety.

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An Empirical Study on the Factors Affecting e-Learning Learners Satisfaction (e-Learning 학습자 만족도 영향요인에 관한 연구)

  • Seo, Chang-Gab;Lee, Seok-Yong
    • The Journal of Information Systems
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    • v.18 no.3
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    • pp.1-25
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    • 2009
  • As many universities introduce e-Learning classes as formal courses, numerous research topics relating to c-Learning such as, defining e-Learning, identifying factors affecting successful e-Learning deployment and examining relationships between the factors in e-Learning classes need to be focused on. However, most researches thai have been undertaken only consider the positive side or right functional dimension. This can result in e-Learning dissemination at universities being overlooked. In accordance with this indispensability, the negative factors, which are potentially inherent in e-Learning learner's perception and affect personnel e-Learning acceptance in university classes need 10 be acknowledged. The purpose of this study was to identify the negative factors affecting personnel e-Learning acceptance and to analyze the interrelation among the factors in this research model. The two independent variables avoidable convenience and reliant convenience, based on pilot test results, and self-efficacy and perceived playfulness, based on the relevant literature, are used to examine the research model. The research problem was tested with data collected from 446 respondents in 12 universities. This study developed and empirically analyzed a model representing the relationship by using the Structural Equation Model. The major findings of this study are, firstly, that the higher reliant convenience is negatively affecting the degree of system use and learner satisfaction, whereas avoidable convenience is only affecting the learner satisfaction. Secondly, the higher self-efficacy and stronger perceived playfulness affects the degree of system use as well as learner satisfaction. Finally, the degree of system use affects the learner satisfaction.