• 한국재료학회지
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• 제23권4호
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• pp.250-254
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• 2013

In order to increase the toughness of ZTA(zirconia toughened alumina) ceramics, the present study focused on rearrangement and densification of particles according to the particle size of the parent material. When rough alumina was used for production of ZTA, densification behavior was observed in the specimen sintered at a temperature over $1550^{\circ}C$. However, it was found that the densification behavior was occurred in the specimen sintered at $1450^{\circ}C$ when fine alumina powder was used. High relative density exceeding 98% was obtained when fine alumina powder was mixed with 15 wt% of 3Y-TZP and sintered at $1600^{\circ}C$. Also, a hardness of 1820.2 Hv was obtained when a specimen containing 10 wt% of 3Y-TZP was sintered at $1600^{\circ}C$. In the case of 3Y-TZP containing rough alumina powder that had been sintered the hardness value was around 1720.3 Hv. It was predicted that an improved toughening effect in ZTA could be achieved by using finer alumina powder as the parent material.

• 가정과삶의질연구
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• 제29권5호
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• pp.121-140
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• 2011

The purpose of this study is to understand how the economic conditions and needs of single-parent families are different between single-mother and single-father families, and also how they are dependent on household composition. The data for this study were drawn from the 1st Korea Welfare Panel Study and analyzed by frequencies, means, ${\chi}^2$, t-test, F-test, and logistic regression with the STATA 9.1 program. The major findings are as follows: (1) Single-parent families are more likely to live in a three-generation household than married couple families. (2) The composition of a three-generation household of single-parent families is affected by sex, age, education, type of marital disruption, the type of employment of single parents and the age of the last-born child. (3) The income-to-needs ratio is not significantly different depending on the sex of the single parents and their household composition. However, material hardship is significantly low in three-generation household single-parent families. (4) There are differences between three-generation single-parent families and independent single-parent families in income sources: The ratio of public transfer to total incomes is higher in three-generation households than independent households, while the ratio of private transfer to total incomes is higher in independent households.

• 한국생활과학회지
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• 제20권4호
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• pp.745-757
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• 2011

The purpose of this study was to explore status of mathematical interactions between parent and child and use of mathematical materials at home. For this purpose, questionnaires were developed. The framework of the questionnaires consisted of mathematics education content domains. 276 parents(4-5 year old children) in J Province responded to the questionnaires, which were analyzed according to the level of home income, the mother's work conditions and the mother's level of education. The results were as follows: First, between parent and child mathematical interaction at home showed a 2.84 score in average and frequency of mathematical interaction expressed in the domains of 'Understanding of regularity', 'Measurement', 'Growing number sense', 'Space and shapes', 'Organizing data and showing results'. The domains of 'Growing number sense', 'space and shapes', and 'measurement' showed significant difference only by mother's level of education. The higher the mother's level of education, the more frequent the mathematical interaction between parent and child. Second, the use of mathematical materials showed an average score of 1.18, which means mathematical materials were practically not used at home. Also, the use of mathematical materials showed a slightly significant difference when measures against the levels of home income and the mother's level of education. The results showed a significant difference in parent-child mathematical interactions, and the possession and use of mathematical materials when measures against by level of home income and the mother's work conditions. Therefore, the results of this study suggest that the parent education program for mathematical interaction to apply at home and mathematics curriculum to be connected early in childhood education institution and home should be developed for parents.

• 대한기계학회논문집A
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• 제24권12호
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• pp.3096-3103
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• 2000

High temperature material properties of a welded joint were experimentally studied. Tensile and creep properties were measured for each part of weld metal. HAZ(heat affected zone) and parent metal at 538$^{\circ}C$. HAZ metal was obtained by a simulated heat treatment. Results showed that the order of tensile strength is weld>HAZ> parent both at 24$^{\circ}C$ and at 538$^{\circ}C$. Creep resistance was also the highest for weld metal and lowest for parent metal. Creep rupture life curves were obtained and converted to Monkman-Grant relation which is useful for life assessment. Use of the data obtained in this study is discussed.

• 부모자녀건강학회지
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• 제22권1호
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• pp.1-9
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• 2019

Purpose: The purpose of this study is to develop educational material for parents of hospitalized preschool children who receive nebulizer therapy treatment. The educational material is aimed at providing information on the correct use of nebulizer. Methods: The development of educational material was based on the ADDIE model and consists of an A4-sized leaflet and a video. Results: The leaflet included basic information, procedures, and cautionary information for nebulizer therapy, as well as frequently asked questions. The one minute and fifty second video is accessed via QR code and provides step-by-step instruction on nebulizer therapy. Conclusion: This study recommends that the educational leaflet and video developed for nebulizer therapy use be provided to parents of preschool children hospitalized in the pediatric ward.

• 대한조선학회논문집
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• 제40권3호
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• pp.54-60
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• 2003

Fatigue strength of offshore structures or ship structures is significantly decreased due to corrosive environment condition such as sea water and/or coal, crude oil of cargoes, compared to that of on shore structures. In corrosive environment, fatigue strength of structures also depends on characteristics of weld material heat affected zone(HAZ). In this research work, rotary bending fatigue tests of parent material and HAZ of TMCP steel were performed in order to investigate the initiation and propagation of cracks both in air and in NaCl solution. Comparison of fatigue strength In relation with the salinity of NaCl were carried out as well. According to the test results weld material or HAZ of TMCP steel showed higher fatigue strength than that of the parent material. The fatigue strength of TMCP steel decreases drastically in NaCl solution compared to that of in air environment. In particular, more reduced fatigue strength is observed in 1% NaCl solution than in 3% NaCl solution.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2010년도 춘계학술발표대회
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• pp.27.2-27.2
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• 2010

In recent years, there is a strong requirement of low cost, stable microelectro mechanical systems (MEMS) for resonators, microswitches and sensors. Most of these devices consist of freely suspended microcantilevers, which are usually made by the etching of some sacrificial materials. Herein, we have attempted to use Si nanowires, inherited from the parent Si wafer, as a sacrificial material due to its porosity, low cost and ease of fabrication. Prior to the fabrication of the Si nanowires silver nanoparticles were continuously formed on the surface of Si wafer. Vertically aligned Si nanowires were fabricated from the parent Si wafers by aqueous chemical route at $50^{\circ}C$. Afterwards, the morphological and structural characteristics of the Si nanowires were investigated. The morphology of nanowires was strongly modulated by the resistivity of the parent wafer. The 3-step etching of nanowires in diluted KOH solution was carried out at room temperature in order to control the fast etching. A layer of $Si_3N_4$ (300 nm) was used for the selective fabrication of nanowires. Finally, a freely suspended bridge of zinc oxide (ZnO) was fabricated after the removal of nanowires from the parent wafer. At present, we believe that this technique may provide a platform for the inexpensive fabrication of futuristic MEMS.

• 대한가정학회지
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• 제48권4호
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• pp.13-24
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• 2010

The aims of this study were to investigate relation the effects of parent-children relationship on marriage attitude among unmarried persons and to utilize the findings as source material in assessing changes to marriage and family value. In total 654 unmarried persons above the age of 20 in this study. A survey format was used to asked questions, and collected data were subjected to descriptive and comparative analysis using the SPSS(Version 15.0) program. The results were as follows. Among socioeconomic variables, religion was significantly relate to marriage attitude(p < .001). Parent-child relationship and psychological separation was significantly related to marriage value(p < .05). Specifically, high psychological separation from mother, and relationship with father was related to more positive marriage attitudes. Finally, effective socioeconomic variables in marriage attitude were religion, job, psychological separation from mother and father.

• 대한가정학회지
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• 제47권6호
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• pp.91-108
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• 2009

The aim of this study was to assist the development of parenting-aid policies by analyzing information from life perspectives, family system theory, and integrated family policy perspectives. For this purpose, we conducted a literature using a variety of sources including internet sites, laws, published material related to current parenting-aid policies. Based on analyses we formulated four agendas: empowering parent competency, supporting diverse family parenting, guaranteeing parent's rights, and supporting parenting of dual-income families parenting. The results were as follow: Firstly, for empowering parent competency, we proposed the development of family relationship empowerment programs including family life cycle and children-raising support services. Secondly, for diverse family parenting, we proposed access to integrated parenting-aid programs dependent on family types. Thirdly, for guaranteeing parent’s rights, we proposed the supporting of child raising costs and tax returns to families with children, and provide child allowances. Finally, for dual-income family parenting, we proposed that schools and communities must recognize that dual-income families are a universal family type, establish family friendly business culture, and to develop a more democratic domestic family-relationship. This policy proposed a new paradigm where parents must be recognized as partners and stakeholder in development of family related policies. Ultimately, such policies will contribute to increased birth rate and development of a more respectful society.

• 한국아동복지학
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• 제55호
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• pp.1-29
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• 2016

본 연구는 서울아동패널 3차년도 데이터를 활용하여 가구소득이 아동의 학업성취에 미치는 영향을 확인하고, 그 과정에서 부모의 시간적 물질적 투자가 매개효과를 지니는지를 살펴보았다. 그 결과, 가구의 소득은 아동의 학업성취에 통계적으로 유의한 정적인 영향을 미치는 것으로 나타났다. 특히 가구소득과 아동 학업성취의 관계를 설명하는 구체적인 매개 경로를 파악하기 위해 부모의 시간적 투자와 물질적 투자가 아동의 학업성취에 미치는 영향을 분석하였다. 그 결과, 부모의 물질적 투자를 나타내는 변수들(인지적 자극물 제공, 교과 외 활동 투자)을 통해 가구소득이 아동의 학업성취에 미치는 영향이 매개되는 것을 확인할 수 있었다. 그러나 부모의 시간적 투자를 나타내는 변수들(부모와의 외부활동, 부모의 학교생활 관여)에서는 통계적으로 유의한 매개효과가 확인되지 않았다. 이러한 결과를 바탕으로 교육불평등에 대한 사회복지 영역에서의 정책적 실천적 개입 방안을 제언하였다.