• 한국수학교육학회지시리즈C:초등수학교육
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• 제3권2호
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• pp.115-131
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• 1999

The purpose of this study is to examine meaning, factors, and diagnostic method of underachievers in mathematics and to propose the idea of the individualized teaching method for underachievers. For the first purpose, previous literatures on underachievers are reviewed. For the second purpose, this study described the procedure of developing the individualized instructional program, and the method of diagnosing and prescribing errors in mathematics. In the future, individualized instructional program need to be developed based on correct diagnosis of factors effecting under achievement for the effective teaching of underachievers.

• 소성∙가공
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• 제24권3호
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• pp.161-166
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• 2015

The finite element method has been widely used in the analysis of ring rolling. For ring rolling it requires a high computational expense due to the non-steady state material flow characteristics of the process. The high computational expense causes the finite element analysis to be impractical for industrial applications. In the current study, we aim to develop a practical implicit finite element modeling method for ring rolling. This method uses a step-wise steady state assumption and is called the “Stepped method”. The stepped method divides the whole process time of unsteady-state flow model into a finite number of steady-state models. It then solves the process at several specific time steps until convergence is reached. In order to confirm the performance and validity of the newly proposed stepped method, the result from the stepped method were compared to the results from a Lagrangian finite element method and to results from experiments reported in the literature.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.99-104
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• 2006

Accurate flow rate distribution has been become a very important part for controling of air change rate since the introduction of house ventilation system. An inappropriate selection of fan due to Incorrect prediction of friction loss makes waste energy. The purpose of this study is to recognize applicability of T-Method at house ventilation system by comparing experiment with T-method, The result of this study is as follows Flow rate is small amount in a house, so duct size must be accurate. And duct design with Equal Friction Loss Method presented large error range. Equal friction loss method is not fit to applicate small amount air flow rate. T-Method predicts accurate flow rate comparatively in a house ventilation system. Error range was 3.5%.

• 복식
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• 제41권
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• pp.185-206
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• 1998

The purpose of this study was to improve productivity for maximum effects with the present equipments and staff. This study compared and analyzed the mea-sured time by using stop watch method and MTM, which was the new measuring method. The flow and results of this study were as follows: 1. This study investigated the theoretical background the efficiency for production management, and the way of productivity improvement through documentary research. 2. Setting up the standard flow on the experi-mental company production, making out a process chart and measuring the actual working hour. 3. The study measured the allowance time applying work sampling. 4. Each process of the movement analysis was filmed by video to use basic data. 5. MTM analysis was taken by choosing 10 processes from front bodice according to the basic movement of MTM. Through the results, this study exclude unneccesary movements and suggest a method for working ways. 6. Using the actual working hour measured by a stop watch calculated the pitch time and presumed the amount of daily productivity. 7. The result of the work sampling came out as 38% of allowance rate. It was 13% higher than the standard amount of woman's jacket allowance rate, which was 25%. The most influencing factor was work discussion. That was because there were commuication problem of the work way between the operator and leader. More adequate use of flow table and level passing table was needed. There were the problems that inappropriate places and sizes made the distance of movements longer and often needed more adjustment of works and surroundings. To prevent breakdowns equipments check ups were necessary before works. 8. The results of MTM analysis were as follow : the time was reduced 40% than the actual measured time by a stop watch. This was because the leveling of the operator was included in the real calculation. Also, leveling was included in MTM analysis and all the conditions were standarized. Therefore MTM method was a scientidic measuring way of establishing the standard time. The presented method of this study, suggested an ideal method eliminating unneccesary motions, and presented standardization of works. Improvement of working methods, work condition and simplifying motions in each 10 processes reduced the working time from total 656 seconds to 301 seconds. 9. The way and time of working was linked together in the MTM analysis methods. Thus data from MTM help suggest not only establishing standard time but also establishing stan-dard work. Plus it includes various ability for improvements of working ways. So it is an objective method which can be widely used in other work studies. 10. The function of a time study is to determine the amount of work produced with a given method. The work rate is used to establish the cost of labor. The wage of worker must be calculated per unit time which is deter-mined before the time study is made. This study tried to introduce the incentive rule for deciding wages according to the standard time by MTM method.

• 한국실내디자인학회논문집
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• 제22권2호
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• pp.186-193
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• 2013

In the commercial space, the modern consumers want to consume not only product but also culture. Thus, the modern commercial space tries to induce the customer's concern and purchase to the differentiated design. The introduction of this 'the natural element' delivers the pleasure and stability to the consumer buying process and availability is enlarged. Therefore, the purpose of study is gain that expression and characteristic method of the natural element in the commercial space. The detailed study method are as follows. First, the study looks into the natural element expression tendency in the modern space. Second, the expression type of the natural element was classified as 'Reappearance', 'Transformation', and 'Fuse' based on the preceding research. And according to the content of the expression type, subdivided method of 'Inclusion' and 'Replication' of 'Reappearance' and method of 'Imitation' and 'Association' of 'Transformation' and method of 'Juxtaposition' and 'Combine' of 'Fuse'. Third, the result of analyze the characteristic of expression of the natural element of the besides the commercial space case 20 place is as follows. First, 'Inclusion' of 'Reappearance' introduced the external scenery or planned garden as the inside through the opening. 'Replication' is used for decorative purposes or functional purposes as the natural element. 'Imitation' of 'Transformation' imitated the form, pattern, and color of the natural element and was mainly expressed in the wall and objet. The method of 'Association' expressed the concept of the natural element for the whole of the space and a portion of the wall and objet repetitively. As for 'Juxtaposition', mixture of 'Reappearance' had a good visual effect, because it can be obtained the external-internal nature. As for 'Combine', mixture of 'Replication' and 'Imitation' was the most common method. Thus, the study results are expected to be utilized as base date in designing the commercial with development of the natural element application method.

• 한국도서관정보학회지
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• 제28권
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• pp.93-135
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• 1998

The purpose of this study was to compare the effectiveness of programmed instruction versus lecture and discussion method on the knowledge of basic reference sources among undergraduate library and information science students. The hypotheses of the study were: 1. Programmed instruction will be more effective than the lecture/discussion method with regard to academic achievement. 2. There will be a significant difference in learning time between the experimental and the control groups. Seventy-eight library and information science students were participated m the study from the two universities in Chungchong Province. A programmed instruction manual, including 4-types of reference sources-dictionary, encyclopaedia, bibliography, indexes and abstracts, 40-item multiple choice post-test, and a questionnaire for the students' attitude toward programmed instruction were developed specifically for this research. The post-test only control-group design was selected for this experimental study. Students were given instruction on the specific reference titles in dictionary, encyclopedia, bibliography, indexes and abstracts. The control group was instructed by the lecture and discussion method while the experimental group completed a programmed instruction manual by themselves. Both the control and the experimental group were tested right after the instruction of 4-types of reference sources. In addition, a questionnaire asking students' attitude toward programmed instruction was administered to the experimental group. The findings from this study are summarized as follows: 1. The results showed that there were no significant difference in the mean of the post test score between the two groups. Therefore, programmed instruction is viable as an alternative method of instruction in the teaching of reference sources. 2. There was a significant difference in the mean of time spending for the leaning of bibliography, indexes and abstracts between the two groups. Accordingly, programmed instruction proved to be more efficient than the conventional lecture/discussion method in terms of learning time. 3. Students showed positive response to programmed instruction and evaluated it very interesting and challenging. In conclusion, the programmed instruction method was just as effective as the lecture/discussion method in the teaching of reference sources. And students' attitude toward the programmed instruction was favorable enough to secure a continued use of this method for the teaching of reference sources.

• 한국건설관리학회논문집
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• 제18권5호
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• pp.3-10
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• 2017

HBS 슬래브는 PSC슬래브 상부에 경량체를 설치하고 이웃하고 있는 PSC슬래브의 두 개 리브가 현장 토핑 콘크리트에 의해 형성된 현장 리브와 결합함으로서 동일축상에서 단일 부재로 거동하는 공법이다. 본 연구의 목적은 PSC 슬래브 공법에 관하여 실험적 연구를 통하여 기존 공법과의 성능 비교를 구현 하는 것이다. 본 연구에서는 기존 공법의 한계를 개선하는 공법으로 HBS 슬래브를 개발하였으며 그 우수성을 검증하기 위하여 기존 공법과의 성능 비교를 시행하고자 한다. 기존 공법과의 구조 성능 비교는 HBS 슬래브의 실험적 연구를 통하여 휨성능 및 전단에 대한 구조 성능과 PC보와 HBS 슬래브의 접합 성능을 검토하였으며, 이론적 방법을 통하여 기존 공법과 비교를 수행하고자 한다.

• 설비공학논문집
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• 제2권3호
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• pp.243-255
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• 1990

The objective of this study is to present an efficient measurement method of the effective thermal diffusivity for the fibrous insulation material. The non-linear parameter estimation (NPE) method is adapted for this analysis because of its accuracy and its results are compared with those by other direct methods such as CTP, CHP and STD method. A experimental system is constructed with bell-jar vaccum chamber, diffusion pump, tube type furnace, control unit and data acquisition system included with A/D converter and IBM XT/AT personal computer. The typical results obtained from this study are as follows; 1) NPE method can be recommended as an useful and accurate method to measure the effective thermal diffusivity of insuation material because it is shown that the measurement error compared with those by other direct methods is reduced for standard material, NBS-1450b. 2) NPE method can minimize the effects of ill-measured temperature due to external disturbance, because the final value is found by point to point estimating. 3) NPE method dose not depend on the kinds of heat flux, since the surfac temperature are used to estimate the thermal diffusivity. 4) With NPE method, compared with the steady state method, a measuring time and a sample size could be reduced.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2001년도 학술논문발표회
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• pp.99-117
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• 2001

In the past, The selection of individual method of construction was done by head of construction site or an experienced person very frequently. By doing this, The wrong selection of construction method without exact adjudication of construction site situation lead to increasing of cost and extension of construction term. Finally it will effect all over the construction process. Especially, In case of Underground construction in the beginning, there are a lot of a variable factor and it also effect on the entire construction process and it need rely careful process. The purpose of this study is to present the best suitable methodology fer selection of construction method by considering potential risk of construction method and variables together with external condition for Underground construction. The purpose of this study is to select the most suitable construction method by analysing potential conditions(Construction site situation and Client. Request in designing) To do this, We prepared arrangement rule to arrangement conditions for construction method. And then make Checklist the analyzing construction method. Though above process, To expect the risk of individual construction method using above risk checklist and using Analytic Hierarchy Process among Multiple-Criteria Decision Making, the professional opinions is to be adapted. By doing this, It can lead and select the most suitable considering method considering the data which get from risk density test.

• 국제강구조저널
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• 제18권5호
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• pp.1508-1524
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• 2018

Hysteretic energy dissipating devices (HEDDs) have been increasingly applied to building construction to improve the seismic performance. The seismic responses of such damped structures are significantly affected by HEDD's structural properties. An accurate investigation on the propagation of HEDD's structural properties is required for reasonable evaluation of the seismic performance of a structure. This study aims to develop simplified methods that can estimate the collective uncertainty-propagation to the seismic response of damped structures employing HEDDs. To achieve this, three- and six-story steel moment-resisting frames were selected and the propagations of the individual HEDD's property-uncertainties were evaluated when they are subjected to various levels of seismic demand. Based on the result of individual uncertainty-propagations, a simplified method is proposed to evaluate the variation of seismic response collectively propagated by HEDD's property-uncertainties and is verified by comparing with the exact collective uncertainty-propagation calculated using the Monte Carlo simulation method. The proposed method, called as a modified SRSS method in this study, is established from a conventional square root of the sum of the squares (SRSS) method with the relative contributions of the individual HEDD's property-uncertainty propagations. This study shows that the modified SRSS method provides a better estimation than the conventional SRSS method and can significantly reduce computational time with reasonable accuracy compared with the Monte Carlo simulation method.