• Speech Sciences
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• v.5 no.1
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• pp.49-62
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• 1999

This study is concerned with the educational program Visual Analysis Tool (VAT) for sound development for foreign intonation using personal computer. The VAT can run on IBM-PC 386 compatible or higher. It shows the spectrogram, waveform, intensity and the pitch contour. The system can work freely on either waveform zoom in-out or the documentation of measured value. In this paper, intensity and pitch contour information were used. Twelve French sentences were recorded from a French conversational tape. And three Korean participated in this study. They spoke out twelve sentences repeatly and trid to make the same pitch contour - by visually matching their pitcgh contour to the native speaker's. A sentences were recorded again when the participants themselves became familiar with intonation, intensity and pauses. The difference of pitch contour(rising or falling), pitch value, energy, total duration of sentences and the boundary of rhythmic group between native speaker's and theirs before and after training were compared. The results were as following: 1) In a declarative sentence: a native speaker's general pitch contour falls at the end of sentences. But the participant's pitch contours were flat before training. 2) In an interrogative: the native speaker made his pitch contours it rise at the end of sentences with the exception of wh-questions (qu'est-ce que) and a pitch value varied a greath. In the interrogative 'S + V' form sentences, we found the pitch contour rose higher in comparison to other sentences and it varied a great deal. 3) In an exclamatory sentence: the pitch contour looked like a shape of a mountain. But the participants could not make it fall before or after training.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.753-756
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• 2008

Recently, construction work period reduction is a very important topic of construction business circles. Because that is just big cost reduction. There is an important part of construction to decide the removal time of form. For prediction strength for removal form, P type schmidt hammer method and maturity method is used that. In case early strength prediction of maturity method, that is problem. Because setting duration of concrete is not proper considering. So this experimental study is a coefficient(A) of maturity method.

• Korean Chemical Engineering Research
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• v.55 no.2
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• pp.214-219
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• 2017

In this work, we fabricated PS-b-P4VP block copolymer membranes from self-assembly and non-solvent induced phase separation (SNIPS), which combines the block copolymer self-assembly and conventional NIPS process. While previous studies mostly focused on the fabrication of well-defined structures, we systematically examined various processing parameters such as polymer concentration, solvent evaporation duration, solvent composition, and humidity, to optimized the membrane structures. As a result, the morphology of PS-b-P4VP membranes was optimized at a certain polymer concentration in solution and composition of volatile solvent at low humidity conditions, resulting in SNIPS separation membranes with well-defined nanopores on the surface, 75% of membrane porosity, and 18% of surface porosity.

• Journal of the Korea Institute of Building Construction
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• v.16 no.2
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• pp.151-159
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• 2016

Tower crane (T/C) is one of the major equipment that is highly demanded in construction projects. Especially, most high-rise building projects require T/C to perform lifting and hoisting activities of materials. Therefore, lifting plan of T/C needs to reduce construction duration and cost. However, most lifting plan of the T/C in construction sites has still performed depending on experience and intuition of the site manager without systematic process of rational work. Dependency structure matrix (DSM) is useful tool in planning the activity sequences and managing information exchanges unlike other existing tools. To improve lifting plan of T/C efficiently, this study presents a framework for the scheduling T/C using DSM through the case study in real world construction site. The results of case study showed that the scheduling T/C using DSM is useful to optimize the T/C lifting plan in terms of easiness, specially in the typical floor cycle lifting planning.

• Women's Health Nursing
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• v.7 no.3
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• pp.382-392
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• 2001

The purpose of this study is to investigate breast-feeding and breast-feeding health behavior among korean first-time mothers and to provide basic data for promoting breast- feeding. Data were collected by interview or self report from 444 first-time mothers who visited health clinic center in the area of metropolitan, medium or small city, countryside. and whose infants were under 12 months old from January 2001 to February 2001. The results show that breast-feeding was 31.5% in a week after childbirth, 25.8% in 4 weeks after childbirth, 22.7% in 2 months, 17.8% in 3 months, 14.3% in 6 months, 2.5% in 12 months after childbirth. Breast-feeding rate was very low in Korea and the duration of breast-feeding was very short. Breast-feeding health behavior did not show significant differences by general characteristics of the subjects except area. The subjects in the health clinic center with MCN project did better breast feeding health behavior than the subject in the health clinic center without MCN project. To raise breast-feeding rate, several strategy could be suggested. Systemic education about importance and advantages of breast-feeding and desirable breast-feeding method should be provided to pregnant women and postpartum women. Childbirth leave in the work should be prolonged, and supportive facility such as nursery room should be installed for working mothers. Hospitals should follow the guideline of 'Baby Friendly Hospital Initiative' which was provided by UNISEF and WHO, including rooming-in after delivery.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.5
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• pp.510-519
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• 2013

In this study, the spray characteristics of a pressure swirl atomizer classified into a liquid sheet-type swirl nozzle for Urea-SCR system were investigated experimentally with the variation of injection pressure. The length to diameter ratio ($l_o/d$) of the nozzle was 3.1, and the swirler was set inside the nozzle tip to give injecting fluid angular momentum. The injection duration of the nozzle was controlled by PWM (pulse width modulation) modes. The development processes of the spray were imaged by a 2-D PIV system, and the change of spray angle was measured. The atomization characteristics, including axial velocity and SMD, were measured using a 2-D PDA system with the injection pressures at room temperature and ambient pressure conditions. As the experimental results, the injection pressure had a significant impact on the spray structure showing a different shape around the spray leading edge, and the smaller SMD was observed with increasing injection pressures, which was similar to that of the previous work.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2017.05a
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• pp.604-605
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• 2017

The present work aims at visualization of the supersonic air jet flows discharged from C-D nozzles. In the present experiments, Prticle Image Velocimetry (PIV) was employed to specify the jet flow field quantitatively, and a color Schlieren optical method was applied to observe the same jets qualitatively. The $0.5{\mu}s$ duration of spark light source was used for Schlieren and it can be controled as $0.5{\mu}s$, $1{\mu}s$, $2{\mu}s$ and focusing mode. The convergent-divergent nozzles were used to generate the jet flow with the design Mach number of 2.0, 2.2. Nozzle pressure ratios (NPRs) were varied from 5 to 8. A good comparison of the jet size and shock location from the Schlieren images with the PIV quantitative values is obtained. The obtained images clearly showed the major features of the under-expanded jet, over-expanded jet, sound wave, turbulent eddies and so on.

• Korea journal of population studies
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• v.20 no.2
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• pp.5-42
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• 1997

This study contributes to understanding women's labor market behavior by focusing on a particular set of labor force transitions - labor force withdrawal and entry during the period surrounding the first birth of a child. In particular, this study provides a dynamic analyses, using longitudinal data and event history analysis, to conceptualize labor force behaviors in a straightforward way. The main research question addresses which factors increase or decrease the hazard rates of leaving and entering the labor market. This study used piecewise Gompertz model, following the guide of the non-parametric analysis on the hazard rates, which allowed relatively detailed description on the distribution of timing of leave and entry to the labor market as parameters of interest. The results show that preferences and structural variables, as well as economic considerations, are very important factors to explain the labor market behavior of women in the period surrounding childbirth.

• Korea journal of population studies
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• v.20 no.2
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• pp.43-66
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• 1997

This work examines reemployment processes through the use of event history unemployment data in the United States. Two aspects of these processes, the duration of unemployment and changes in the reemployment rate, are modelled and analyzed in terms of individual characteristics and their structural positions in the labor market. The secondary labor market is a competitive market in which unemployment occurs because people quit their jobs to devote more time in search for better jobs. Using search theory, the rate of reemployment has a positive time dependence as the searcher lower her reservation wage with the passage of time. By contrast, the primary market is characterized by long-term employment relations which reduce voluntary turnovers but generate layoffs temporarily. Relying on contract theory, because workers on temporary layoffs wait for recall, reemployment rates have a constant time dependence. Empirical results of unemployment durations indicate that reemployment processes are influenced by individual's positions in dual labor market structures. While the analysis suggests that the amount of search reemployment seems to be positively related to the degree of competitiveness of a market, somewhat weaker results are noted in the search reemployment processes in competitive markets.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.288-293
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• 2013

Purpose: Number of arthroscopic surgery is gradually increasing with development of its equipment and technique. Arthroscopic ankle surgery performed with the traction device has various complications and need more time for preparation. We investigated whether the complication rate increased when surgery was performed without the traction device, and compared the complication rate of arthroscopic surgery with the traction device. Materials and Methods: From January 2009 to June 2012, arthroscopic ankle surgery was performed without the traction device in four hundred eleven cases. There were two hundred sixty-one males and one hundred fifty females. The average age at operation was 35 years (range, 17-56), and the average follow up period was 28 months (range, 12-41). Postoperative symptoms and complications were checked. Results: There were difficulties performing arthroscopic surgery without the traction device in five cases with severe traumatic osteoarthritis. However, after burring and shaving, we had enough space to work on. Superficial peroneal nerve symptom was found in two cases, grooving of talus was found in 11, and saphenous vein injury was found in five. Since preparing for the traction device was unnecessary, we were able to save time with the mean duration of surgery of 50 minutes (range, 30-120). Conclusion: With only manual traction, we could explore the entire ankle joint without damage on cartilage. Yet, skilled arthroscopic technique will be necessary for arthroscopic surgery without the traction device.