• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.23 no.7 s.166
• /
• pp.1094-1103
• /
• 1999

Ice-plugging of tube in nuclear power plant has been widely used for the purpose of preventing flow of the tube temporarily like a valve. Most common plugging method employs Liquid Nitrogen Gas of $-196^{\circ}C$. According to the change of tube materials and its dimension, the thermal stress caused from the application of the frozen gas can be varied. In this research, a series of experiments have been carried out to inspect the effect of tube geometry on thermal stresses induced due to ice-plugging. Two typical dimension of stainless and mild steels of 3 and 6 inch diameters were used for the experiments. Each critical spots were checked using strain rosette gages. Another inspection was made on the pressure and temperature of the fluid. It is shown that significant thermal stress level which can cause plastic deformation of failure has not been noticed in this series of experiments.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.13 no.2
• /
• pp.43-50
• /
• 2007

The production, distribution, and consumption of Korean medicinal herbs have increased every year because of an increase of health considerations. But there are no sufficient standardization procedures in packaging and distribution systems related to these herb products. The standardization of packaging material and dimension could be a good addition for establishing proper quality control methods for Korean medicinal herbs. Medicinal herbs deteriorate under physical, chemical and biological hazards such as oxidation, textural change under high moisture content, color change by light, sanitation problems by insect invasion and contamination. Packaging standardization with proper functional packaging materials is critical to ensure the qualities of medicinal herbs. Also, storage and distribution efficiencies can be improved by achieving packaging dimension standardization. This review summarizes recent research trends related to quality evaluation methods and major quality deterioration factors of Korean medicinal herbs. This paper also offers reviews on some of problems and challenges in current packaging and distribution systems of medicinal herb industries and briefly suggests advanced quality control methods through packaging standardization.

• Journal of Korea Foundry Society
• /
• v.13 no.6
• /
• pp.547-554
• /
• 1993

Aluminum alloy matrix composites reinforced with various amounts of $Al_2O_3$ short fibers have been produced by rheo-compocasting accompanied by hot pressing. When composites reinforced with fibers are produced by rheo-compocasting, S-L process is the most effective method for homogeneous dispersion of fibers. A sound composites with the improved orientation(3 dimension${\rightarrow}$2 dimension) of the fibers and increased volume fraction of them have been fabricated through the hot pressing of the casted composites. Fibers are broken down when rheo-compocasting, hot pressing, and $T_6$ treating. Among them fibers are broken down most heavily in the hot pressing. And even in the case of the composite reinforced with 30 vol% fibers, which showed the hardest fiber break down, aspect ratio(11.6) is higher than critical aspect ratio(10.7). The fiber strengthening effect in the composites has showed upto 573K. As the test temperature increases to the range of 573K, the effect has been higher. The fracture of composites is controlled by fiber from room temperature to 473K, but the fracture of composites is controlled by interface between fiber and matrix alloy above 473K.

• Journal of the Korean Society of Manufacturing Process Engineers
• /
• v.13 no.4
• /
• pp.7-12
• /
• 2014

A transparent poly methyl methacrylate (PMMA) optical micro-pyramid array-pattern is designed and fabricated using an injection modeling technique. The device's optical characteristics are tested and analyzed theoretically. In the optical pattern generated using the fabricated PMMA pattern, the components, due to not only refraction but also diffraction, are observed simultaneously. Wave optic modeling and analysis reveals that the energy ratio between the diffraction and refraction in the optical pattern are dependent on the critical dimension of the optical pattern such that the refraction and diffraction tend to be directly and inversely proportional to the pattern dimension, respectively.

• Journal of the Korean Physical Society
• /
• v.73 no.11
• /
• pp.1760-1763
• /
• 2018

To attain power generation with body heat, the thermal resistance matched design of the thermoelectric generator was the principal factor which was not critical in the case of thermoelectric generator for the waste heat generation. The dimension of thermoelectric legs and the number of thermoelectric leg-pairs dependent output power performances of the thermoelectric generator on the human wrist condition was simulated using 1-dimensional approximated heat flow equations with the temperature dependent material coefficients of the constituent materials and the dimension of the substrate. With the optimum thermoelectric generator design, thermoelectric generator modules were fabricated by using newly developed fabrication processes, which is mass production possible. The electrical properties and the output power characteristics of the fabricated thermoelectric modules were characterized by using a home-made test set-up. The output voltage of the designed thermoelectric generator were a few tens of millivolts and its output power was several hundreds of microwatts under the conditions at the human wrist. The measured output voltage and power of the fabricated thermoelectric generator were slightly lower than those of the designed thermoelectric generator due to several reasons.

• Journal of the Korean Home Economics Association
• /
• v.41 no.10 s.188
• /
• pp.149-171
• /
• 2003

This study was carried out as a basic fundamental research to propose a theoretical framework for Home Economics curriculum. This research employed the Delphi Method to reach a consensus with the experts in each related educational field of study for putting forth a newly proposed theoretical framework of a Home Economics curriculum. The finally proposed theoretical framework will definitely play a crucial role in establishing a standard framework for educational goals and curriculum content for Home Economics curriculum since it is put forth with a strong agreement from a high proportion of the expert groups. Results on the nature and characteristics of, structural framework of curriculum contents, and literacy through Home Economics were drawn from the 3-round Delphi survey: 1. Home economics has a liberal and practical-critical nature and it promotes enhancement of quality of life through a practical problem-solving process in maintaining family life. 2. The structural framework of the home economics curriculum contents is organized with three-dimensional components of content area (dimension 1), process area (dimension 2), focus of organizing content (dimension 3). 3. One's empowering capability through home economics education is proposed: inquiring knowledge and understanding phenomena for future society, solving practical problems in family life, developing higher order thinking skill, cultivating a positive attitude and a values system toward life.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.30 no.3
• /
• pp.238-245
• /
• 2014

In order to create denture occlusion that is functional, comfortable and balanced, it is necessary to both determine a vertical dimension of occlusion that is in harmony with the patient's musculature and to record a relatively repeatable jaw relation position. This require clinical skill to establish an accurate, verifiable and reproducible vertical dimension of occlusion (VDO) and centric relation (CR). Correct vertical relation depends upon a consideration of several factors, including muscle tone, inter-dental arch space and parallelism of the ridges. Centric relation is considered to be a repeatable position from which all opening and lateral mandibular movements begin and recording this position is a critical step in the fabrication of dentures. Any errors made while taking maxillo-mandibular jaw relation records will result in denture that are uncomfortable. The purpose of this paper is to review a very simple and efficient technique for accomplishing these two important steps in denture fabrication.

• Korean Journal of Child Studies
• /
• v.4
• /
• pp.23-35
• /
• 1983

The purpose of this study is to systematize the theory of the father-child relationship by analyzing the father's role and father-child interaction. The results of this study are as followings: (1) The oedipal period 3 to 5 years is a critical in development of the father-child relationship. Father absence is assumed in infancy but it is denying because the father participates in Child- rearing activity. (2) The Father's role is symbolized instrumental role traditionally and culturally but it is appropriate that we think the father's role to be androgynous concepts. Instrumental role as well as expressive role is expected to father's role. (3) The role of the father is supplementary mother's role. The father provides economic, emotional support and helps the balanced child- rearing. This indirect role of the father is very important. (4) The father influences child development, and his role is to be sex-role model to contrieve personality internalize moral development. But it is needed more empirical study to clarify father's effects on child development. (5) The amount of time that fathers spend with their children is less than mothers, but it is not assumed that difference of this amount of time do not differently influence to the children. (6) There are much similarity that difference between father-child interaction and mother- child interaction. Qualitative difference in interaction is response style. A responsive style of the father is physical intellectual instructive but mother's is verbal. (7) The effects of the father to a child must be analyzed on dyadic dimension and triadic dimension of family network. In triadic dimension, father influences mother- child relationship, mother to response sensitively, husband-wife relation.

• Korea journal of population studies
• /
• v.34 no.3
• /
• pp.55-84
• /
• 2011

This study initiated with the intention to reveal the social consultations and fissures through a comparative analysis on generational characteristics by indicating occupation-related identities with the concept of social identity supported by theoretical resources. According to the three dimensions of social identity which are evaluation, potency and activity, there was more generational agreement rather than difference toward occupation-related identities. Among the 44 identities, only evaluation dimensions on minister, congressman, plane captain, farmer and potency dimensions on CEO of a major companies, professor, medical doctor, nurse, celebrity, shaman, unemployed person were statistically significant. For 'Leader and Professional', the respondents in their 50's gave high scores in both evaluation and potency dimensions. On the other side, the 30's had negative viewpoints while the 20's and 40's had neutral perspectives. For the potency dimension, the age groups were divided into the 20's, 30's and 40's, 50's; having the younger generations underestimate the potency dimension of such categories. Also for the 'General Occupation', 20's and the 30's relatively devaluated with more distinctive degree toward evaluation dimensions. For religion, 20's and 30's were positive toward buddhist monks while the 40's and 50's were more favorable with priests. For the non-economically active population, the lifetime cycle influenced each generations. When performing a two dimensional analysis toward the 'Leader and Professional' with evaluation and potency on each axis, the 50's highly evaluated both evaluation and potency dimension of such identities. However, for the 40's, 30's and 20's, the average value fell while the focus of the distribution deepened. The 30's had negative perspective toward the evaluation dimension while the 20's reflected critical attitude toward the potency dimension.

• Journal of Christian Education in Korea
• /
• v.70
• /
• pp.11-35
• /
• 2022

The purpose of this article is to suggest nine types of educational ministry based on the practical theology in Christian Education. For the purpose this article emphasizes an individual dimension including church, society dimensions. An individual dimension is based on the spirit of post digital era within sociocultural area in different with personal-existential area of the philosophical and theological perspective and life cycle theology area of the developmental psychological perspective. Post digital era means the humanization of digital, digital friendly, and emotional digital cultural characteristics. Post digital generation means child, youth, young adults those who are accustomed with post digital cultural of the post digital era. The educational ministry for the post digital generations categorized into nine types according to correlation with individual, church, and society as a field of ministry and critical scientific method, critical confessional method, and critical correlational method as an interdisciplinary which are composed of Christian tradition and contemporary science. Representative key competencies of nine types in the educational ministry are media literacy, relational identity, communication, high touch, discipleship, making and using media, integrative vocation, collaboration abilities, and home, school, and social resilience in relation with multicultural generations.