• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.4
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• pp.558-567
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• 2020

This study examined the defect characteristics of fuel flow proportioner-mounted structures to analyze the causes of structural defects during aircraft operation. System vibrations and single component vibrations that occur during aircraft operations are usually the cause of structural defects. The fuel flow proportioner causes a defect in the support structure due to the vibration caused by the pressure change caused by the sudden increase in the flow rate. Defects in the support structure of the fuel flow proportioner are not correlated directly with the cracking of the maneuver, and flight time according to aircraft operation analysis is related to the use of A/B. The structural reinforcement configuration was confirmed through static and life analysis of the cracks of the bracket mounted under the fuel flow proportioner for improvement of the defect. An analysis of the reinforcement revealed a minimum structural strength of +0.15. Structural life analysis confirmed that the stress acted on the site under 15Ksi. The fatigue life was confirmed to be more than 7,700 Cycles.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.61-62
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• 1993

고분자 분리막의 투과성과 선택성을 향상시키기 위하여 IPN막, 고분자/액정 복합막을 다양한 기능을 가진 재료가 개발되고 있다. 본 연구에서는 알칼리메탈이온을 분리하기 위하여 고분자 지지체에 운반체로써 crown ether(macro-cyclic polyether)류를 분산시킨 고분자/운반체 복합박막을 제조하였다. 고분자/운반체 복합박막은 고분자와 운반체의 혼합용액을 수면에 전개시켜 제조하였다. 고분자는 PVC(M.W 60000, Aldrich), PS(M.W 280000, Aldrich)와 CA(M.W 30000, Sigma)를 사용하였고, 운반체로는 crown ether 중 $K^+$이온과 선택성을 가지는 18-Crown-6(Sigma)를 사용, 고분자와 18-Crown-6의 증량분을 달리하는 혼합용액을 제조하였다. 이때 용매는 Tetrahydrofuran를 사용하였다. 수면에 생성된 박막을 다공성 지지막에 적층시킨 후 감압 건조시켜 복합막을 제조하였다. 고분자와 운반체가 혼합되어 있는 용액의 점도와 표면장력을 각각 fluid spectrometer와 tensionmeter를 사용, 용액이 수면위에서 완전한 막을 형성하면서 분산될 수 있는지 조사하였으며, 고분자 지지체에 분산 고정된 운반체의 분산형태와 표면농도를 조사하기 위하여 ESCA를 이용하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.12
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• pp.1229-1235
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• 2015

Scaffold fabrication technology using a 3D printer was developed for damaged bone tissue regeneration. A scaffold for bone tissue regeneration application should be biocompatible, biodegradable, and have an adequate mechanical strength. Moreover, the scaffold should have pores of satisfactory quantity and interconnection. In this study, we used the polymer deposition system (PDS) based on fused deposition modeling (FDM) to fabricate a 3D scaffold. The materials used were polycaprolactone (PCL) and alginic acid sodium salt (sodium alginate, SA). The salt-leaching method was used to fabricate dual pores on the 3D scaffold. The 3D scaffold with dual pores was observed using SEM-EDS (scanning electron microscope-energy dispersive spectroscopy) and evaluated through in-vitro tests using MG63 cells.

• Women's Health Nursing
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• v.7 no.2
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• pp.188-202
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• 2001

This study was designed to investigate the effect of one-to-one labor support on labor pain, labor stress response, childbirth experience and neonatal status for primipara by a quasi experiment (nonequivalent control group pretest-posttest design), from April 30, 1999 to February 20, 2000. The subjects of this experiment consisted of eighty two primipara with single gestation, full term, uncomplicated pregnancies. Forty one were in the experimental group and forty one in the control group. Their mean age was 25.95 years, their mean gestation period was 39.9 weeks. A caring package of one-to-one labor support had three components. Physical support consisted of massage, back pressure, touch. Emotional support was provided by a continuous nurse's presence, acceptance and encouragement. Informational support involved teaching breathing skills, relaxation skills and knowledge about the labor process. Data assessed labor pain, pulse rate and blood pressure to measure labor stress response. Also, in measuring the value of labor stress response, plasma epinephrine, plasma norepinephrine and serum cortisol were measured. In the 24 hours after birth, the data for the postpartum mother's childbirth experiences was collected. Umbilical cord arterial blood pH, one minute and five minute Apgar score were measured after birth. Data was analyzed by t-test, $x^2$-test, repeated measures ANOVA, ANCOVA with SAS Program. The results were as follows; 1. Labor pain was significantly low in the experimental group(P=.016). 2. No significant group effects were found, but significant time effects were found for plasma epinephrine, norepinephrine, serum cortisol, pulse rate and blood pressure. 3. The childbirth experience of the experimental group was significantly more positive than the control group (P = .005). 4. The umbilical cord arterial blood pH of the experimental group was significantly higher than the control group(P=.014). There was no significant difference between the two groups in neonatal one minute and five minute Apgar scores. In conclusion, these findings indicate that one-to-one labor support could be effective in decreasing labor pain, and increasing positive childbirth experiences, also increasing the neonatal umbilical cord arterial blood pH for primipara. So, one-to-one labor support could be applied as an effective nursing treatment for primipara.

• Management & Information Systems Review
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• v.31 no.1
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• pp.89-116
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• 2012

This paper is an empirical study for the listed manufacturing companies in the Korea Stock Exchange during the sample period(2001-2010). The research is based on the target adjustment model(Shyam-Sunder and Myers(1999)) and the pecking order model(Frank and Goyal(2003)), and is aimed at reflecting the critical viewpoint of Chirinko and Singha(2000). An analysis in the model of Shyam-Sunder and Myers(1999) shows the value is too low to support the pecking order model in view of the following results. A target adjustment coefficient value is between 0 and 1, and is significant variable and explanatory power is very high, while deficit-in-funds coefficients close to 0. In addition, the result of an empirical test following the methodology used by Frank and Goyal(2003) does not support the pecking order theory.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.82-84
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• 2005

본 논문에서는 기존의 멀티미디어 연관 규칙 알고리즘인 Max occur 알고리즘에서 추출한 빈발 항목 집합의 결과들에 대하여 빈발 항목 집합들끼리의 공간적인 연관 관계를 고려하기 위챈 공간 데이터 마이닝의 대표적인 공간 분할 방법인 그리드 셀 기반으로 곰간 분할 지수(spatial facotr)인 SF를 이용한 이미지 공간 연관 규칙 마이닝 방법을 제시한다. 또한 최소 공간 지지도를 적용하여 이미지 데이터에서 반복적으로 발생하는 항목과 항목간의 공간 관계를 통해 이미지 연관 규칙을 마이닝 하는데 보다 유효한 알고리즘을 제안한다.

• KEPCO Journal on Electric Power and Energy
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• v.3 no.1
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• pp.65-72
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• 2017

This study analyzed causal relationship between electricity consumption and economic output (GDP) for Korea from 2001 to 2014 employing the vector error-correction model estimation by manufacturing sector. The results of unit-roots tests show that all sectoral GDP and electricity consumptions were not stationary. And cointegration tests show that processed foods, Wood Pulp Paper, electricity apparatus, Precision Medical sectors had a linear combinations in the long run between electricity consumptions and economic growth. With respect to the direction of causality, manufacturing sector has a uni-directional running from economic output (GDP) to electricity consumption in short term. The results of study show that sectoral causal relation were different each other in short term and long term. These findings imply that electricity demand management policy focusing on efficiency improvement is necessary to minimize negative impacts on economic growth and to adopt suitable structural policies can induce energy conservation.

• Women's Health Nursing
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• v.4 no.3
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• pp.297-308
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• 1998

The purpose of this study was to define whether NSILQ is useful for the nursing student in supporting women labor room(Nursing Support in Labor Questionnaire). The retrospective study was conducted to identify the helpfulness of nursing student support behaviors as perceived by women in Labor. This sample of 152 women completed two data collection instruments : a demographic & obstetric questionnaire(12) and NSILQ(20). The data were analyzed by Cronbach alpha, descriptive statistics, t-test, ANOVA with SAS program. The result of this study are as follows. 1. All of NSILQ nursing behaviors were perceived as helpful in this study. The total mean of perceived score was $3.4{\pm}0.90$. 2. According to the type of nursing support, the mean of Affect(AT) care was $3.48{\pm}0.79$, the mean of Aid(AD) care was $3.37{\pm}0.82$, the mean of Affirmation(AM) care was $3.35{\pm}0.90$. Among the type of care, the AD care was 52.2%, and the most helpful one. 3. The significant characters of nursing support are antenatal care numbers and husband with or not in labor process. In the group of score of nursing support, the number of antenatal care was low(F=3.90, P=0.02). The score of the group husbands in labor process was higher.(T=4.55, P=0.001). 4. The significant characters of influencing on nursing support required are the person who helped and whether women has job or not. 5. The highest numbers of wanting nursing support are Aid cares(74.3%). The care the women wanted mostly was Aid cares (74.3%; pain control in labor(56.6%), physical comfort(6.6%), coach in labor(3.9%), explain of dilatation(1.3%) in rank.

• Journal of the Korean Geosynthetics Society
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• v.17 no.4
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• pp.73-79
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• 2018

In the west coast, south coast, and river basin, the use of geotextile mats has been increasing to improve the soft ground for making industrial facilities space and farmland. As an initial step to improve the vast and soft ground, the geotextile mats are laid and bonded to increase the bearing capacity of the wide ground for supporting construction equipment. Seam strength of geotextile mats exert a force only about 50% of the tensile strength of the fabric, which causes problems such as uplift and sinking in the soft ground. In this study, various types of geosynthetic matting techniques were investigated and the tensile strength of each method was compared and analyzed. Numerical analysis shows that stress increment in the ground due to the overburden load decreases when the seam strength of the geosynthetics mats is increased. When the seam strength was increased to 60, 70 and 80%, the bearing capacity of ground by geotextile mat was increased.

• Polymer(Korea)
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• v.25 no.4
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• pp.476-485
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• 2001

In this study, we tried to design and synthesize using natural polymers (hyaluronic acid and sodium alginate) and also to make some kinds of scaffolds as sponge type for reducing the burst effect of loaded drug from them. Photo-dimerizable group was incorporated to hyaluronic acid and degradable hydrogel was prepared by the UV radiation of the polymer. The pore size and its distribution of scaffold were controlled by changing microsphere production conditions such as solution concentration and spraying pressure. It was found that drug release behavior from synthesized scaffolds was affected by hybridization of two naturally originated polymers (cinnamoylated tetrabutylammonium hyaluronate: CHT and cinnamolylated sodium alginate: CSA) and the obtained scaffolds were degraded in fairly long time (about 2 months) under in vitro environment. Therefore, we expect that obtained scaffolds can be applicable for the tissue regeneration scaffolds in the fields of orthopaedic surgery.