• 한국구조물진단유지관리공학회 논문집
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• 제2권2호
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• pp.195-201
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• 1998

The purpose of this study is to evaluate the flexural strengthening effects of RC beams reinforced with carbon fiber sheets (CFS) in variable of strengthening amount and anchorage length of CFS. This study can be summarized as follows ; The CFS shares the tensile stress such as rebar during loading test. Also, as the strengthening amount of CFS is increased, the maximum flexural strength of RC beams reinforced with CFS is increased. Therefore, it is confirmed that the CFS's strengthening method is very effective to improve the flexural strength of RC beams. The maximum flexural strength of RC beams with CFS is determined by bond failure between CFS and concrete surface. So, the evaluation of CFS's strengthening effect can be calculated using the tensile stress of CFS which is peeling. When the anchorage length of CFS is increased, the ductility of RC beams is increased because of delaying the peeling of CFS. But, in case of same anchorage length of CFS, when the strengthening amount of CFS is increased, the ductility is decreased. Therefore, it is considered that the anchorage of CFS in the end zone is necessary.

• Wind and Structures
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• 제29권5호
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• pp.313-321
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• 2019

The wind blowing at high velocity in an open storage yard leads to wind erosion and loss of material. Fence structures can be constructed around the periphery of the storage yard to reduce the erosion. The fence will cause turbulence and recirculation behind it which can be utilized to reduce the wind erosion and loss of material. A properly designed fence system will produce lesser turbulence and longer shelter effect. This paper aims to show the applicability of Support Vector Machine (SVM) to predict the recirculation length. A SVM model was built, trained and tested using the experimental data gathered from the literature. The newly developed model is compared with numerical turbulence model, in particular, modified $k-{\varepsilon}$ model along with the experimental results. From the results, it was observed that the SVM model has a better capability in predicting the recirculation length. The SVM model was able to predict the recirculation length at a lesser time as compared to modified $k-{\varepsilon}$ model. All the results are analyzed in terms of statistical measures, such as root mean square error, correlation coefficient, and scatter index. These examinations demonstrate that SVM has a strong potential as a feasible tool for predicting recirculation length.

• 대한치과교정학회지
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• 제49권3호
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• pp.150-160
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• 2019

Objective: This study aimed to analyze the effect of changing various parameters of the bone-borne rapid palatal expander (RPE) using the finite element method (FEM). Methods: In eight experimental groups, we investigated the effect of the number, position, and length of miniscrews; positional changes of the expander; and changes in the hook length on maxillary expansion. In finite element analysis, we compared the magnitude and distribution of stress, and the displacement changes following expansion of the bone-borne RPE. Results: When we compared the number and position of miniscrews, placing miniscrews in the anterior and posterior sides was advantageous for maxillary expansion in terms of stress distribution and displacement changes. Miniscrew length did not significantly affect stress distribution and displacement changes. Furthermore, anteroposterior displacement of the expander did not significantly affect transverse maxillary expansion but had various effects on vertical changes of the maxilla. The maxilla rotated clockwise when the miniscrews were placed in the anterior region. The hook length of the expander did not show consistent results in terms of changes in stress distribution and magnitude or in displacement changes. Conclusions: The findings of this study suggest that changes in the location and length of the miniscrews and displacement of the bone-borne RPE could affect the pattern of the maxillary expansion, depending on the combination of these factors.

• 수산해양기술연구
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• 제48권1호
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• pp.51-58
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• 2012

As a basic study to improve hooking ability of long line fishing gear, which is widely used around Jeju-do coast, the researcher performed hooking experiment of parrot fish by manufacturing and installing 7 kinds of model long line fishing gears, whose thickness of branch line are different and 8 kinds of model long line fishing gear, whose length of branch line are different, in indoor circular aquarium, which is installed for the model experiment of thickness and length of branch line that are various by fishing implement and improper. The hooking rate depending on thickness and length of branch line was calculated and the effect of thickness and length of branch line on hooking rate was analyzed. Its results are as follows. When branch line was thin and long, high hooking rate appeared. In the scope of value setting, the relationship between thickness ($B_t$) of branch line and total hooking rate ($Th_r$) can be shown as following formula as. In the scope of value setting, the relationship between length ($B_t$) of branch line and total hooking rate ($B_t$) can be shown as $Th_r=-20.83B_t+26.04$. Through Pearson correlation analysis, the coefficient of correlation between thickness of branch line and hooking rate was -0.718. Therefore it showed significance in 0.01 significance level. Through Pearson correlation analysis, the coefficient of correlation between length of branch line and hooking rate was 0.431. Therefore it showed significance in 0.01 significance level.

• 한국의상디자인학회지
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• 제13권3호
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• pp.89-103
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• 2011

The purpose of this study is to analyze the formative characteristics of accordion pleats shown in 10/11 S/S London, Paris, New York collection and evaluate the differences of visual image by variations in the width of pleats and the length of the accordion pleats skirt. The stimuli are 21 samples: 7 variations of the width of pleats and 3 variations of the length of skirt. The data has been obtained from 43 fashion design majors. The data has been analyzed by Factor Analysis, Anova, Scheffe's Test. The results of the study are as follows: Accordion pleats was first introduced by Marriano Fortuny. He published delphos dress by creating silk pleats manufacturing technique and it was recognized as the best pleats work. Since then, pleats with synthetic fiber characteristics were used by many fashion designers. Accordion pleats were used in various items including one-peice, skirt and pants in collection of 2010 and 2011. The design of accordion pleats skirt used different width of pleats, length of the skirt and materials. The visual image by the width of pleats and the length of skirt are composed of 3 factors : dearness, attractiveness and elegance. In these factors, dearness factor is estimated by the most important factor. The accordion p1eats skirt is most attractive and dear when the width of pleats is the shortest, 1/8", and the width of 4/8" and 5/8" follows. The accordion pleats skirt is most attractive and dear when the length of skirt is similar to that of mini-skirt, and the skirt was estimated to be elegant as the skirt gets longer. When the length of skirt is in between, the skirts were estimated to be ambiguous in all visual images. The interaction effect of visual image according to the changes in width of pleats and skirt length of accordion pleats skirt was seemed to have significant differences by factors, and the main effect had great differences in all factors.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2002년도 추계 학술발표회 논문집
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• pp.197-201
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• 2002

The healthy worker effect is an important issue in occupational epidemiology. We proposed a new statistical method to test the relationship between exposure and time to death in the presence of the healthy worker effect. In this study, we considered the healthy worker hire effect to operate as a confounder and the healthy worker survival effect to operate as a confounder and an intermediate variable. The basic idea of the proposed method reflects the length bias-sampling caused by changing one's employment status. Simulation studies were also carried out to compare the proposed method with the Cox proportional hazards models. According to our simulation studies, both the proposed test and the test based on the Cox model having the change of the employment status as a time-dependent covariate seem to be satisfactory at an upper 5% significance level. The Cox models, however, are inadequate with the change, if any, of the employment status as time-independent covariate. The proposed test is superior in power to the test based on the Cox model including the time-dependent employment status.

• Structural Engineering and Mechanics
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• 제76권1호
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• pp.27-56
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• 2020

In this paper, the deflection and buckling analyses of porous nano-composite piezoelectric plate reinforced by carbon nanotube (CNT) are studied. The equations of equilibrium using energy method are derived from principle of minimum total potential energy. In the research, the non-local strain gradient theory is employed to consider size dependent effect for porous nanocomposite piezoelectric plate. The effects of material length scale parameter, Eringen's nonlocal parameter, porosity coefficient and aspect ratio on the deflection and critical buckling load are investigated. The results indicate that the effect of porosity coefficient on the increase of the deflection and critical buckling load is greatly higher than the other parameters effect, and size effect including nonlocal parameter and the material length scale parameter have a lower effect on the deflection increase with respect to the porosity coefficient, respectively and vice versa for critical buckling load. Porous nanocomposites are used in various engineering fields such as aerospace, medical industries and water refinery.

• 한국전기전자재료학회논문지
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• 제11권1호
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• pp.26-32
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• 1998

We have studied how the characteristics degradation between effective mobility and field effect mobility of gate channel in p-MOSFET's affects the gate channel length being follow by increased stress time and increased drain-source voltage stress. The experimental results between effective and field-effect mobility were analyzed that the measurement data are identical at the point of minimum slope in threshold voltage, the other part is different, that is, the effective mobility it the faster than the field-effect mobility. Also, It was found that the effective and field-effect mobility. Also, It was found that the effective and field-effect mobility of p-MOSFET's with short channel are increased by decreased channel length, increased stress time and increased drain-source voltage stress.

• 대한가정학회지
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• 제41권9호
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• pp.135-148
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• 2003

The purpose of this study was to examine the effect of clothing colors, clothing styles on women's body image perception. The experimental design was 2${\times}$2${\times}$9(perceiver's gender ${\times}$clothing styles${\times}$clothing colors) factorial design with between-subjects design. Subjects were 320 college students in the metropolitan area of Seoul. Perceiver's gender, clothing styles, and clothing colors gave a significant influence on the 3 variables of shoulder, the upper half of the body, and bust. Shoulder and the upper half of the body had an interaction effect by clothing styles and clothing color. Perceiver's gender gave a significant influence on hip size, length of leg, height, clothing styles did a significant influence on hip size, length of leg, height, and slender figure. Clothing colors gave a significant influence on length of leg, height, and slender figure. Length of leg and slender figure had an interaction effect by perceiver's gender and clothing styles. Hip size had an interaction effect by perceiver's gender and clothing color. Hip size had an interaction effect by clothing styles and clothing color. The results of this study support that coloration of clothing and clothing style affects perception of stimulus persons wearing apparel.

• 복식문화연구
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• 제21권2호
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• pp.220-233
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• 2013

This study examined regarding the moderating effect of length of relationship in the relationship among the antecedent variables (i.e., specific investment, opportunistic behavior, communication, uncertainty, interdependence, power imbalance, shared value, and flexibility) of trust and commitment, trust and commitment and firm performance and relationship satisfaction. A total of 128 apparel manufacturers participated in this study. Flexibility exerted the most positive effect on trust in short-term relationship, followed by specific investment. And opportunistic behavior was found to exert negative effect on trust. Commitment was found to be most negatively affected by power imbalance, followed by interdependence. Trust was shown to be significantly affected by communication, shared value and flexibility in short-term relationship. In the case of long-term relationship, commitment was shown to be significantly affected by uncertainty, interdependence, power imbalance and flexibility. Firm performance was positively affected by both trust and commitment. As for the effect of trust and commitment on relationship satisfaction, relationship satisfaction was also affected by both trust and commitment. In case the length of relationship, firm performance was affected by both trust and commitment. As for the effect of trust and commitment on relationship satisfaction, relationship satisfaction was also affected by both trust and commitment. The result of this research provides valuable data for making a concrete suggestion regarding the strategy for improving trust and commitment for the sake of the desirable relationship between apparel manufacturers and contractors.