• The Korea Swine Journal
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• v.27 no.4 s.308
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• pp.151-154
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• 2005

• The Korea Swine Journal
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• v.27 no.5 s.309
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• pp.112-118
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• 2005

• The tire
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• s.75
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• pp.3-14
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• 1978

• The Journal of the Korea Contents Association
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• v.14 no.6
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• pp.162-173
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• 2014

Among OECD countries, Korea is the only country which has continuously recorded total birthrate below 1.3 person for over 10 years. Since 2006, the Korean government has promoted the population policy in full scale. But, the fertility rate which became low has not shown any sign to go up again. Thus, Korea can be understood as having fallen into 'low fertility trap'. Such a low fertility can cause serious problems such as weakening of national competitive power and even survival of the country. In Korea, due to studies and finding jobs among young women, their childbirths are kept being postponed. In some cases, poor working conditions where women work can cause physical conditions not appropriate for pregnancy. Thus, it is very important to let childbearing women, pregnant women take care of their health. Accordingly, conscious of this low fertility era, this study examined major international organizations and countries' health promoting strategies-with focus on motherhood and suggested some methods to effectively improve health for motherhood.

• Elastomers and Composites
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• v.46 no.2
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• pp.132-137
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• 2011

In the present investigation, thermal aging behavior of H-NBR/NBR blend with various H-NBR content was investigated. Mixture of dicumyl peroxide and sulfur were used as a curing agent. The influence of the thermal aging of the H-NBR/NBR blends on the solid state properties such as tensile strength, elongation at break, hardness and abrasion resistance was investigated. Tensile strength was increased with increasing H-NBR content, while abrasion resistance was decreased. Both elongation at break and hardness were not affected by the addition of H-NBR. The properties such as hardness, tensile strength and elongation at break of the aged samples were lower than unaged samples. However, the rate of deterioration of those properties was decreased by increasing the H-NBR content, which indicated that improved thermal aging behavior was obtained by the addition of H-NBR. Abrasion loss was increased with increasing aging time, but it became less by the addition of H-NBR addition.

• Journal of East-West Nursing Research
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• v.23 no.2
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• pp.134-141
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• 2017

Purpose: The purpose of this study was to investigate the effects of the maternal health care program on pregnant women's depression, maternal role self-confidence and delivery self-efficacy in a public health center. Methods: This study used a non-equivalent control group quasi-experiment design attempted to verify the effectiveness of maternal health care program. In the experimental group (39 participants), maternal health care program was applied for 120 minutes for 8 weeks, and the control group (40 participants) was provided with a booklet for maternal health care. Data collection was conducted from September 20, 2015 to November 30, 2015. Data were analyzed using ${\chi}^2-test$, Fisher's exact test and t-test. Results: The maternal health care program showed a significant effect on maternal role self-confidence and delivery self-efficacy compared to control group. Conclusion: The maternal health care program conducted at the public health center was found to be effective in improving maternal role self-confidence and delivery self-efficacy. Further development of a program to mediate the depression of the expectant mothers is needed.

• Proceedings of the Korean Vacuum Society Conference
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• 2000.02a
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• pp.190-190
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• 2000

침질탄화처리는 표면경화처리의 화학열처리 종류로서 지난 수 십년동안 많이 사용된 방법이며 값싼 철강재료 즉 보통탄소강, 저합금강 등에 내마모성, 내부식성 및 내피로성 향상에 사용되어 왔다. 그리고 자동차 부품, 기계류 부품, 공업용 공구 등에 적용할 수 있으며 염욕 및 가스를 매체로 사용한다. 침질 탄화처리는 질소와 탄소가 동시에 철재료로 확산 침투하여 최표면에 탄질화물의 화합물층을 형성하고 화합물층 아래에 확산층을 형성하는데 일반적으로 화합물층이 단상의 $\varepsilon$화합물일 때 내마모성과 내부식성을 확산층이 내피로성질을 향상시킨다. 이러한 염욕과 가스 침질탄화 처리에도 불구하고 플라즈마 화학열처리는 가스방법에 비해 현저하게 가스 소모량이 적고 에너지 효율이 높으며 현제 문제시되는 환경오염이 전혀 없기 때문에 크게 각광받고 있다. 현재 플라즈마 침진탄화처리에 많은 연구를 하였음에도 불구하고 단상의 $\varepsilon$화합물층을 형성시키는 어려운 문제점으로 남아 있으며 대부분의 화합물층은 최표면의 $\varepsilon$상과 ${\gamma}$'상으로 구성되어 있고 이러한 혼합상의 화합물층은 $\varepsilon$상과 ${\gamma}$'상의 방위가 서로 불일치하기 때문에 마모시에 미소크랙을 유발시켜 내마모성을 저하시키는 요인으로 작용한다. 따라서 본 연구에서는 CH4 가스를 사용하여 내마모성과 내부식성을 향상시키는 단상의 $\varepsilon$화합물층 생성가능성을 고찰하고자 하였다. 침진탄화 처리시간을 변화시켰을 때 화합물층의 생성은 ${\gamma}$'상으로부터 시작되고 $\varepsilon$상은 즉시 ${\gamma}$'상을 소모하면서 생성되어 일정시간이 지난 후 $\varepsilon$상은 안정화되며 질소가스농도가 증가할수록 화합물 층내의 $\varepsilon$상분율은 역시 증가하였다. 한편 CH4 가스농도는 처리되는 강종에 따라 차이를 보이며 적정 CH4 가스농도를 초과시에는 $\varepsilon$상 생성은 억제되고 시멘타이트상이 생성되었다.

• Clean Technology
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• v.15 no.1
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• pp.16-22
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• 2009

In this study, a fiber reinforced plastic (FRP) pipe with superior wear resistance was developed to replace the fly ash pipe of cast iron. Wear test was performed with various combinations of SiC filler and resin materials of unsaturated polyester, vinylester, epoxy, and phenol. Test results of ASTM D4060 showed the optimal combinations of resin, filler size, and resin/filler ratios. Test results of comparison between FRP and cast iron showed the possibility to replace cast iron pipe with the FRP pipe. Field test executed to compare the wear resistance between cast iron pipe and developed FRP pipe showed the superiority of the FRP pipe.

• Journal of Korea Foundry Society
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• v.18 no.6
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• pp.586-592
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• 1998

2.3%C-26%Cr-1%Ni-0.5%Mo 조성의 아공정 백주철을 여러형태로 열처리를 한 후 잔류오스테나이트함량(Vr), 거시 및 미소경도 그리고 내마찰마모성사이의 상호관계를 연구하였다. 주방상태에서의 Vr가 70.2%인 반면 열처리시편들의 경우 0.3-65.4%의 분포를 나타내었다. 초기마모구간 이외에는 마찰마모량과 마모시간과의 사이에 직선적 관계가 얻어졌으며 그 직선의 기울기(Rw)를 내마모성의 비교시 지표로 사용하였다. Rw는 주방상태에서 $2.77{\times}10^{-2}\;mg/s$로 가장 낮았으며 l173k에서 18ks동안 균질화 열처리만 한 시편의 경우 $4.12{\times}10^{-2}\;mg/s$로 내마모성이 가장 열악하였다. 주방상태에서 내마모성이 가장 좋은 이유는 마찰마모시 오스테나이트가 가공경화를 일으켜 마르텐사이트로 변태되었기 때문으로 여겨진다. 미소경도는 HV 358-HV 756, 거시경도는 이 보다 높은 HV 529-HV 785의 분포를 나타내었는데 이는 거시경도의 측정시 공정탄화물인 $M_7C_3$가 포함되었기 때문이다. 가장 높은 미소 및 거시경도는 1323k에서 7.2ks동안 오스테나이화열처리한 시편에서 얻어졌으며 주방상태의 시편이 가장 낮은 경도치를 나타내었다.

• Child Health Nursing Research
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• v.10 no.1
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• pp.117-125
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• 2004

Purpose: The research was conducted to investigate the experience of maternal role attainment of mothers of premature infants admitted in NICU and to conceptualize the phenomena. Method: The grounded theory method was utilized for data collection and analysis. 8 mothers of premature infants were selected and in-depth interview was performed. Paradigm model was utilized for data analysis and presentation. Result: The central category was 'unstable maternal identity'. The properties of the core phenomena was 'ambivalent feeling to baby' 'negative emotion' 'commitment to baby'. The loss of control due to premature delivery was the causal condition. contextual condition was the 'perceived threats' due to severity of the premature infant and uncerainty of the baby's life. The mother's health status, economic status, and familial and social support was recognized as intervening conditions during the process of maternal role attainment. The strategic action/interactions were emotion-focused coping, reappraisal of the situation, problem-focused coping, and information seeking. The consequence was the maternal role attainment with competence and expectation. Conclusion: The process of maternal role attainment was affected by threats due to severity of the baby and intervening factors and interaction strategy. Further research is recommended to develop adequate intervention method during the process of maternal role attainment.