• 대한토목학회논문집
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• 제41권2호
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• pp.101-111
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• 2021

전단마찰 시험체는 재하형태에 따라 압축재하와 인장재하 시험으로 구분된다. 인장재하 시험의 경우에는 외력으로 작용하는 수직방향 인장력에 의하여 전단응력 및 수직방향 인장응력이 유발된다. 이 연구에서는 압축장 이론을 이용하여 인장재하 시험체의 전단전달강도를 평가하였으며, 2축-응력 상태의 콘크리트 최대 압축강도의 변화를 고려하기 위하여 수정압축장이론, 연화트러스모델의 구성방정식을 사용하였다. 타당성 검증을 위하여 과거 연구자들에 의해 수행된 직접전단강도 실험값들과 압축장 이론을 이용하여 구한 값들을 비교한 결과, 비균열 인장재하 시험체의 경우 예측값과 실측치가 대체적으로 잘 일치함을 확인하였다. 또한 콘크리트 스트럿의 유효압축강도를 고려한 전단강도 평가식을 제안하고, 기존 문헌에 수록된 실험결과와 비교함으로써 제안식의 적용 가능성을 검증하였다.

• Communications for Statistical Applications and Methods
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• 제8권1호
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• pp.193-207
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• 2001

When designing a test set, we need to consider constraints on items that are deemed important by item developers or test specialists. The constraints are essentially on the components of the test domain or abilities relevant to a given test set. And so if the test domain could be represented in a more refined form, test construction would be made in a more efficient way. We assume that relationships among task abilities are representable by a causal model and that the item response theory (IRT) is not fully available for them. In such a case we can not apply traditional item selection methods that are based on the IRT. In this paper, we use entropy as an uncertainty measure for making inferences on task abilities and developed an optimal item selection algorithm which reduces most the entropy of task abilities when items are selected from an item pool.

• 영어어문교육
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• 제18권1호
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• pp.171-195
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• 2012

While noticing that there is insufficient interest in the assessment of EFL learners' vocabulary levels or sizes, the researchers developed two tests identical in form (Forms A and B) to assess the lexical knowledge of Korean university learners at the $1^{st}{\sim}10^{th}$ 1,000 word bands by adapting a pre-established vocabulary levels test (VLT). Of equal concern was to investigate if the VLT was equally a valid and reliable instrument to be used on measuring the lexical knowledge of EFL learners. The participants were 804 university freshmen enrolled in a General Education English Course from four different colleges. The learners were asked to respond to either Form A or B. While scores generally fell towards the lower frequency bands, multiple regression found the Korean College Scholastic Ability Test (CSAT) to be a significant variable for predicting the learners' vocabulary sizes. From a methodological perspective, however, noticeable differences between Forms A and B could be found with item response theory analysis. The findings of the study provide suggestions on how future VLT for testing EFL learners may have to be redesigned.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2000년도 춘계학술대회논문집
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• pp.831-836
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• 2000

In this study, the Rayleigh inextensional theory and extensional theory for thin shells was employed to predict the natural frequencies of the hemi-spherical shell with free and simply. supported boundary condition. The frequencies and mode shapes from theoretical calculation were compared with those of commercial finite element code, ANSYS. In order to validate the theory, modal test was also performed by impact test and FFT analysis. Modal test and FEM analysis of the free, simply supported and clamped boundary condition was also carried out.

• 대한간호학회지
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• 제35권6호
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• pp.1044-1053
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• 2005

Purpose: This study was aimed to evaluate the effects of a maternal education program based on the temperament theory on the temperamental goodness-of-fit between mother and child. Method: The research method was a nonequivalent, control group, non-synchronized design and the experimental period was from May 10, 2004 to July 24, 2004. The subjects were mothers who had children 3-4 years old who registered in eight kindergartens or infant schools in M city. Among the total 94 subjects, 47 were allocated as an experimental group and 47 were a control group. Using the SPSS/WIN 10.0 program, the data was analyzed by a Chi-square test, and t-test. Result: 1. After treatment with a maternal education program based on the temperament theory, the experimental group significantly decreased in scores for perceived children's behavior problems in comparison to the control group(t=-4.01, p<.001). 2. After treatment with a maternal education program based on the temperament theory, the experimental group did not significantly decrease in scores for parenting stress in comparison to the control group(t=-.85, p=.40). 3. After treatment with a maternal education program based on the temperament theory, the experimental group did not significantly decrease in scores for rejective parenting behaviors in comparison to the control group(t=-1.32, p=.19). Conclusion: A maternal education program based on the temperament theory is a useful intervention to decrease perceived children's behavior problems.

• 대한간호학회지
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• 제32권1호
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• pp.16-27
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• 2002

This study was conducted to develop and test the hypothetical model which explains smoking cessation behavior was established based on the Triandis' interpersonal behavior theory. Method: The data were collected from the 400 university student smokers enrolled in the universities located in Seoul and Kyung-In province. The study was analyzed by path analysis with LIESREL 8 program. Results: All of the fit statistics, except the Chi-square value, it showed the hypothetical model was well fitted to the data. Benefit, affect, and social influences related to smoking cessation behavior had significant direct effect on intention to smoking cessation as shown in the study of the hypothetical model. Perceived barrier and the physiologic arousal related to smoking cessation had significant direct effects on performing smoking cessation behavior, whereas numbers of previous attempts to quit smoking and intention to smoking cessation did not.

• Asia pacific journal of information systems
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• 제28권2호
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• pp.133-153
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• 2018

This study investigates responses to privacy concerns by analyzing the psychological and behavioral characteristics related to the disposition toward invoices of courier service users. To this end, we develop a theoretical framework by combining stimulus response theory, communication privacy management theory, the theory of reasoned action, and the theory of planned behavior. Based on the theoretical framework, we analyze the relationships between social influence, privacy propensity, privacy control, privacy risk, privacy concern, invoice disposition intention, and invoice disposition behavior in the context of courier services. To test our hypotheses, we survey courier service users in the U.S. and Korea. Using a structural equation model, we test the relationships among these various factors for the courier service users of the two countries. Results have distinct implications for the psychological and behavioral characteristics concerning the disposal of courier invoices and enable understanding of the characteristics of courier service customers of the two countries.

• 유통과학연구
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• 제13권9호
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• pp.47-57
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• 2015

Purpose - The aim of this paper is to investigate the explanatory power of the Pecking-order theory (the cost of financing increases with asymmetric information) among Korean retail firms from the perspective of debt capacity. According to the Pecking-order theory, a firm's first preference is to use internal funds for its capital needs, its next preference is the issuance of debt, and its last preference is the issuance of equity; this is due to the information asymmetry problem between existing shareholders and investors. However, prior empirical studies, such as Lemmon and Zender (2010), argue that the entire sample test for the Pecking-order theory could be misleading due to the different levels of debt issuance capability of each of the individual firms; in fact, they confirm that the explanatory power of the Pecking-order theory improves after taking into account the differences in debt capacity of the U.S. firms they examined. This paper implements a case study approach among Korean retail firms to examine the relationship between debt capacity and the explanatory power of the Pecking-order theory in Korea. Research design, data, and methodology - This study uses the sample of public retail firms on the Korea Composite Stock Price Index (KOSPI) from the time period of 1990 to 2013. We gather related financial and accounting statements from the financial information firm WISEfn. Credit rating information is provided by the Korea Investor Service. We employ the models of Lemmon and Zender (2010) and Son and Kim (2013) to measure a firm's debt capacity. Their logit models use the rating dummy variable as a dependent variable and incorporate other firm characteristics as independent variables to estimate debt capacity. To test the Pecking-order theory, we adopt variants of the financing deficit model of Shyam-Sunder and Myers (1999). In the test of the Pecking-order theory, we consider all of the changes in total debt obligations, current debt obligations, and long-term debt obligations. Results - Our main contribution to the literature is our confirmation of the predicted relationship between debt capacity and the explanatory power of the Pecking-order theory among Korean retail firms. The coefficients on financing deficits become greater as a firm's debt capacity improves. This is consistent with the results of Lemmon and Zender (2010). The coefficients on the square of the financing deficits are also negative for the firms in the largest debt capacity group, which is also consistent with the predictions in prior literature. Conclusions - This study takes a case study approach by examining Korean retail firms. We confirm that the Pecking-order theory explains the capital structure of retail firms more appropriately, after taking into account the debt capacity of each firm. This result suggests the importance of debt capacity consideration in the testing of the Pecking-order theory. Our result also implies that there has been a potential underestimation of the explanatory power of the Pecking-order theory in existing studies.

• 수산경영론집
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• 제45권1호
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• pp.1-16
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• 2014

The study attempts to show that the theory of critical environmental variation quantum(CEVQ) has a sound logical basis and empirical support. It is well known that the theory of critical environmental variation quantum is derived from the theory of biological probability distibution function and the central limit theorem(CLT) in statistics. The study uses the case study of fisheries damages compensation caused br the public marine construction undertaken in the area do Anjeong Bay in the city of Tongyeong for empirical test of theory of CEVQ. The results shows that the CEVQ theory perfoms a good job in measuring quantatively fjsheries damages caused by outflow of cold water due to the operation of LNG company since 2002. Therefore the study proves that the CEVQ theory is a good theory having internal consistency and empirical applicability.

• Structural Engineering and Mechanics
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• 제75권4호
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• pp.487-496
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• 2020

Most of the previous works on numerical analysis of galloping of transmission lines are generally based on the quasisteady theory. However, some wind tunnel tests of the rectangular section or hangers of suspension bridges have shown that the galloping phenomenon has a strong unsteady characteristic and the test results are quite different from the quasi-steady calculation results. Therefore, it is necessary to check the applicability of the quasi-static theory in galloping analysis of the ice-covered transmission line. Although some limited unsteady simulation researches have been conducted on the variation of parameters such as aerodynamic damping, aerodynamic coefficients with wind speed or wind attack angle, there is a need to investigate the numerical simulation of unsteady galloping of two-dimensional iced transmission line with comparison to wind tunnel test results. In this paper, it is proposed to conduct a two dimensional (2-D) unsteady numerical analysis of ice-covered transmission line galloping. First, wind tunnel tests of a typical crescent-shapes iced conductor are conducted firstly to check the subsequent quasisteady and unsteady numerical analysis results. Then, a numerical simulation model consistent with the aeroelastic model in the wind tunnel test is established. The weak coupling methodology is used to consider the fluid-structure interaction in investigating a two-dimension numerical simulation of unsteady galloping of the iced conductor. First, the flow field is simulated to obtain the pressure and velocity distribution of the flow field. The fluid action on the iced conduct at the coupling interface is treated as an external load to the conductor. Then, the movement of the conduct is analyzed separately. The software ANSYS FLUENT is employed and redeveloped to numerically analyze the model responses based on fluid-structure interaction theory. The numerical simulation results of unsteady galloping of the iced conduct are compared with the measured responses of wind tunnel tests and the numerical results by the conventional quasi-steady theory, respectively.