• Journal of the Korean housing association
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• 제17권6호
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• pp.55-63
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• 2006

The purpose of this study is to investigate the change of kitchen in a single detached house in Jeonju city after 70's. Oral life history method which has 12 women's personal narratives and 17 women's personal narratives with written reports was used as a research method of this study. The results of the study were obtained as follows: 1) It was beginning about late 1970 year that heating system and cooking place were separated in a house. 2) Many kitchens were reconstructed for indoor stand-up work place from late 1970's to the early 1980's. 3) There were major factors such as heating system, cooking fuel, and work center in the change of kitchen in old houses. 4) The kitchen toward the center with a living room was appeared in the floor plan of modem house after 1990's. The symbolic words of the indoor kitchen that work for women were 'warmness' and 'convenience'.

• Journal of Families and Better Life
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• 제22권1호
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• pp.153-167
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• 2004

The purpose of this study was to investigate the difficulties, conflicts, and communications between female-headed single parents and their children, their child rearing methods and attitude, and the political suggestions for the welfare in those families. The in-depth interviews were conducted for 7 women in Gyonggi-Do and Chungnam-Do on March 3-27, 2003. The interviewees were selected for the mothers whose children were enrolled either elementary schools or middle schools. The contents of interviews were receded to be analyzed by qualitative method. The results were as follows; first, female-headed single parent families were in low economic status with unstable employment condition. Secondly, women in that families were confronted with psychological problems because of their multiple roles and low income. Third, although they had a controlled child rearing method, they used much reinforcement and praise. Thirdly, they were in need of the aids for the basic life such as housings and their children's private institute expenses. Finally, they required the repealing of an existing birthright system.

• Journal of Family Resource Management and Policy Review
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• 제24권4호
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• pp.21-37
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• 2020

This study focuses on the leisure activities of young, single-person households. Data collection involved selecting and interviewing eight cases. The results are as follows: 1. The leisure activities of young, single people are divided between weekdays and weekends. 2. Important factors affecting these leisure activities are time, money, and cognition. 3. Respondents maintain their work-life balance by focusing on weekdays and weekends, they work and study intensively on weekdays and spend their time and money on leisure and rest on weekends. 4. Young people want a chance to meet and share their experiences with others. This point must be central to planning the Healthy Family Support Center program.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제16권5호
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• pp.3633-3642
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• 2015

Single-base propellants contain a single energetic component: nitrocellulose. Accurate predictions of propellant shelf-life should result in cost savings in terms of human and material resources. This study derived an optimized kinetic model reaction order that described stabilizer consumption and estimated propellant shelf-life. High temperature accelerated aging tests gave an optimum reaction order value of 1.15481, from which the minimum standard error of a linear regression estimate of 16.284 was obtained. At normal storage temperature of $21-30^{\circ}C$, propellants should have a safe shelf-life of 140 years, and a minimum of 35 years. It is necessary to consider the temperature range in ammunition storage areas to predict propellant shelf-life more accurately.

• Transactions of the Korean Society of Mechanical Engineers A
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• 제26권3호
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• pp.471-478
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• 2002

In real structures, multi-spot welded joints are more frequently used than a single-spot welded joint. Most researches, however, have been focused to a single-spot welded joint until now. In this paper, the fatigue behavior of multi-spot welded joints are investigated using the finite element solutions of the multi-spot welded specimens. The local strain approach is used rather than the stress intensity factor approach to estimate the fatigue life since the former is quite simple and straightforward. It is found that the fatigue behavior of multi-spot welded joints is different from that of single-spot welded joints. The local strain approach is still applicable to multi-spot welded joints.

• International Journal of Stem Cells
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• 제16권3호
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• pp.342-355
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• 2023

Background and Objectives: Osteoblasts are derived from bone marrow mesenchymal stem cells (BMMSCs) and play important role in bone remodeling. While our previous studies have investigated the cell subtypes and heterogeneity in osteoblasts and BMMSCs separately, cell-to-cell communications between osteoblasts and BMMSCs in vivo in humans have not been characterized. The aim of this study was to investigate the cellular communication between human primary osteoblasts and bone marrow mesenchymal stem cells. Methods and Results: To investigate the cell-to-cell communications between osteoblasts and BMMSCs and identify new cell subtypes, we performed a systematic integration analysis with our single-cell RNA sequencing (scRNA-seq) transcriptomes data from BMMSCs and osteoblasts. We successfully identified a novel preosteoblasts subtype which highly expressed ATF3, CCL2, CXCL2 and IRF1. Biological functional annotations of the transcriptomes suggested that the novel preosteoblasts subtype may inhibit osteoblasts differentiation, maintain cells to a less differentiated status and recruit osteoclasts. Ligand-receptor interaction analysis showed strong interaction between mature osteoblasts and BMMSCs. Meanwhile, we found FZD1 was highly expressed in BMMSCs of osteogenic differentiation direction. WIF1 and SFRP4, which were highly expressed in mature osteoblasts were reported to inhibit osteogenic differentiation. We speculated that WIF1 and sFRP4 expressed in mature osteoblasts inhibited the binding of FZD1 to Wnt ligand in BMMSCs, thereby further inhibiting osteogenic differentiation of BMMSCs. Conclusions: Our study provided a more systematic and comprehensive understanding of the heterogeneity of osteogenic cells. At the single cell level, this study provided insights into the cell-to-cell communications between BMMSCs and osteoblasts and mature osteoblasts may mediate negative feedback regulation of osteogenesis process.

• Genomics & Informatics
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• 제14권1호
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• pp.29-33
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• 2016

A retron is a bacterial retroelement that encodes an RNA gene and a reverse transcriptase (RT). The former, once transcribed, works as a template primer for reverse transcription by the latter. The resulting DNA is covalently linked to the upstream part of the RNA; this chimera is called multicopy single-stranded DNA (msDNA), which is extrachromosomal DNA found in many bacterial species. Based on the conserved features in the eight known msDNA sequences, we developed a detection method and applied it to scan National Center for Biotechnology Information (NCBI) RefSeq bacterial genome sequences. Among 16,844 bacterial sequences possessing a retron-type RT domain, we identified 48 unique types of msDNA. Currently, the biological role of msDNA is not well understood. Our work will be a useful tool in studying the distribution, evolution, and physiological role of msDNA.

• Journal of Korean Society of Industrial and Systems Engineering
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• 제24권68호
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• pp.1-7
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• 2001

A probabilistic model for fatigue life of a structural component is derived when the component is in a variable-amplitude loading environment. The physical mechanism which governs fatigue failure is used to model the fatigue life. Especially, the judgement of rotational symmetry in the-stress-intensity-factors results in the probability distribution for fatigue life. The probability distribution is related to the familiar truncated Gaussian distribution, which has a single parameter with a direct physical meaning.

• Journal of Family Resource Management and Policy Review
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• 제27권2호
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• pp.35-47
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• 2023

The purpose of this study was to understand family changes and dynamics of and to suggest institutional/policy-level tasks for coping with them, by paying attention to changing family values of single-person households and their caring work performed in everyday life. This study selected 11 single-person households residing in Ulsan by considering their age and marital status, and analyzed their overall daily lives, family values, and the characteristics of household work and caring. The characteristics of these single-person households in Ulsan, not only showed the coexistence of "simplicity, but instability" when maintaining and living their own lives, but also showed the ambivalent characteristics of family values by showing a gap between the perception and reality of diversity. In regard to family life, the participants complained of difficulties in "caring and relationship of family of origin" and the "economic factors", and notably showed the "dual value system". For a more stable life, the single-person households were forming social networks to relieve a sense of isolation and loneliness, and to recover relationships, instead of limiting themselves to only the traditional method of family formation. Thus, it would be possible to respond to family changes when changes are promoted in each area of "the perception of life", "family life", and the "family & social relationship", and this research suggests policy-level tasks based on the results of this study.

• Journal of Microbiology and Biotechnology
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• 제27권5호
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• pp.965-974
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• 2017

The single-chain variable fragment (scFv) against lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) is a promising molecule for its potential use in the diagnosis and immunotherapy of atherosclerosis. Producing this scFv in several milligram amounts could be the starting point for further engineering and application of the scFv. In this study, the abundant expression of the anti-LOX-1 scFv was attempted using Escherichia coli (E. coli) and Brevibacillus choshinensis (B. choshinensis). The scFv had limited soluble yield in E. coli, but it was efficiently secreted by B. choshinensis. The optimized fermentation was determined using the Plackett-Burman screening design and response surface methodology, under which the yield reached up to 1.5 g/l in a 5-L fermentor. Moreover, the properties of the scFvs obtained from the two expression systems were different. The antigen affinity, transition temperature, and particle diameter size were 1.01E-07 M, $55.2{\pm}0.3^{\circ}C$, and 9.388 nm for the scFv expressed by B. choshinensis, and 4.53E-07 M, $52.5{\pm}0.3^{\circ}C$, and 13.54 nm for the scFv expressed by E. coli. This study established an efficient scale-up production methodology for the anti-LOX-1 scFv, which will boost its use in LOX-1-based therapy.