• Journal of the Korean Geosynthetics Society
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• v.16 no.2
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• pp.1-10
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• 2017

This study carried out several laboratory tests such as water tank settlement test and two-dimensional water flow test to investigate settlement and scour characteristics of a square-shaped hybrid reef which was reinforced with geogrid. In addition, numerical analysis was also performed to find out scour characteristics of the square-shaped hybrid reef with different placement types (type A; straight placement type, type B; zigzag placement type). Laboratory test results indicated that settlement and scouring depth significantly reduced in hybrid reefs reinforced with geogrid, compared with those without reinforcement. Two-dimentional water flow tests and numerical test results also showed that scouring depth and flow velocity of placement type A more decreased than those of type B.

• Journal of Korean Tunnelling and Underground Space Association
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• v.11 no.3
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• pp.213-221
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• 2009

This paper presents the concrete placement method of tunnel lining to improve the concrete lining quality such as cavities, cracks of the concrete lining. In order to perform this study, the occurred cracks initially in the concrete lining are reviewed and analyzed. From the review, the improvement methods to minimize the defects of concrete lining are suggested. To confirm the efficiency of new concrete placement approaches and the scale of tunnel section, two types of the scaled model tests are carried out and analyzed in model scales of 1/20 and 1/7. The 1/20 scaled model tests are carried out using the existing experimental rigs. The 1/7 scaled model tests are carried out in new test rigs developed in this study. The concrete placement rates obtained from the experimental results are analyzed and compared with themselves. In the existing concrete placement method, 1/20 scale model test than 1/7 scale model test have increased concrete placement rates but It is clearly found that two kinds of experimental studies show the similar results in improvement methods and good agreement with new concrete placing approach.

• Smart Structures and Systems
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• v.4 no.4
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• pp.465-492
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• 2008

Proper pretest planning is a vital component of any successful vibration test on engineering structures. The most important issue in dynamic testing of many engineering structures is arriving at the number and optimal placement of sensors. The sensors must be placed on the structure in such a way that all the important dynamic behaviour of a structural system is captured during the course of the test with sufficient accuracy so that the information can be effectively utilised for structural parameter identification or health monitoring. Several optimal sensor placement (OSP) techniques are proposed in the literature and each of these methods have been evaluated with respect to a specific problem encountered in various engineering disciplines like aerospace, civil, mechanical engineering, etc. In the present work, we propose to perform a detailed characteristic evaluation of some selective popular OSP techniques with respect to their application to practical civil engineering problems. Numerical experiments carried out in the paper on various practical civil engineering structures indicate that effective independence (EFI) method is more consistent when compared to all other sensor placement techniques.

• International Journal of Highway Engineering
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• v.20 no.1
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• pp.97-105
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• 2018

PURPOSES : Asphalt concrete pavement is damaged by various causes such as traffic and environmental loads. The distressed pavement should be maintained by various methods to provide a comfortable and safe pavement for the driver. This study evaluates the effect of adding a mixing procedure to enhance the mixture quality in the hot in-placement recycled asphalt pavement method, which is an asphalt-pavement maintenance method. METHODS : Various test methods such as Marshall stability and dynamic stability, were employed to estimate the recycled asphalt mixture with and without an additional mixing, using the hot in-placement recycled asphalt pavement method. RESULTS : The mixture samples used in this study were taken before and after the addition of the mixer in the hot in-placement recycled asphalt pavement method (HIR) at field construction sites in GongJu and JinJu in South Korea. The test results of both mixtures satisfied the asphalt-mixture standard specifications. CONCLUSIONS : This study confirmed that adding a mixer in the HIR method results in a well-mixed new asphalt mixture, rejuvenator, and reclaimed asphalt mixture.

• English Language & Literature Teaching
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• v.12 no.3
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• pp.147-166
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• 2006

This study investigates the effect of misplacement in a written Computer-delivered ESL Placement Test (CEPT) context. The study aims to address the following two research questions: a) which scoring rubric features cause the misplacement of ESL learner's writing scores? and b) which scoring rubric features improve ESL learner's writing scores? Thirty-four international examinees took the test and participated in surveys at the University of Illinois. Twelve examinees of them attended the CEPT workshop test. In the workshop test, they carried out self-evaluation on their first essays using a scoring rubric and compared with expert raters' results. After the workshop, the examinees responded to a survey and interview. For the first research question, the results of the survey and interview addressed that the majority disagreed with the raters' rating results. The self-evaluation results also indicated that their misunderstanding of organization feature caused the misplacement. For the second question, the CEPT workshop scores were improved due to the score improvement in the organization feature while the contribution of other features to the total scores was little. Most of the examinees pointed out that a lesson on the scoring rubric enhanced their understanding of the writing features of the rubric so that their placement scores were generally improved.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.54 no.12
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• pp.567-572
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• 2005

This paper presents a scheme to design optimal placement of phase-shifting transformers for power system congestion problems. A good design of phase-shifting transformers placement can improve total transfer capability in interconnected systems. In order to find the optimal placement of phase-shifting transformers, the power flows of the interesting transmission lines are evaluated using sequential quadratic programming technique. This algorithm considers power balance equations and security constraints such as voltage magnitudes and transmission line capacities. The proposed scheme is tested in 10 machines 39 buses and IEEE 57 buses systems. Test result shows that the proposed method can find the optimal placement of phase-shifting transformers to solver power system congestion problems.

• Journal of Engineering Education Research
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• v.16 no.4
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• pp.15-20
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• 2013

The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.

• Journal of Engineering Education Research
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• v.14 no.2
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• pp.51-59
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• 2011

The wide range of the Freshmen English placement test scores implies the necessity of differentiating classes. However without a careful and detailed plan, there could be trial and error which would cause harmful and complicated troubles to students. This paper will report a case of grouping Freshmen for English classes at the Engineering College of a provincial university. The main procedures include preparing and executing the placement test, grouping classes, preparing and executing a common final test, preparing grading policy, and reporting. Each procedure is going to be explained and evaluated to improve the quality of English classes and the ability of students at the Engineering College.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1401-1408
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• 2013

Kim and Kim (1992) proposed typical nonparametric method for umbrella alternative in randomized block design with replications. In this paper, We consider a test procedure for umbrella alternatives in a randomized block design using extension of the two sample placement tests described in Orban and Wolfe (1982) and treatment tests described in Kim (1999). We perform a Monte Carlo study to compare the empirical powers of the test statistics for underlying distributions.

• Human Ecology Research
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• v.53 no.4
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• pp.341-350
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• 2015

This study explored the determinant variables influence of Chinese consumers' purchase intention towards products featured in Korean TV dramas vis-$\grave{a}$-vis product placement (PPL). We invited 248 Chinese adult consumers who had watched Korean TV dramas in last twelve months to participate in this survey. Data analyses were conducted by Cronbach's ${\alpha}$ reliability test, confirmatory factor analysis, t -test, analysis of variance and hierarchical multiple regression with SPSS ver. 21.0 and AMOS ver. 21.0. We chose PPL effects, product quality perceptions, and product trust as main independent variables. The empirical analysis results demonstrate that female (versus male) and frequency of (or longer time) watching dramas resulted in higher perceived consumer PPL effects, product quality, trust and purchase intention. The positive effects of the product quality and product trust on purchase intentions were confirmed. There are additional mediation effects of product quality perceptions and trust on the relationship between consumer demographic characteristics (gender), TV drama watching conditions (frequency and time) and purchase intention. This research can help Korean corporations produce effective advertising by indicating how PPL affects Chinese consumer consumption behavior. The results are useful for the Chinese government and consumer organizations to improve the domestic consumption environment by developing effective TV drama PPL policies.