• 대한가정학회지
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• 제34권5호
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• pp.49-66
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• 1996

The purpose of this study is to identify how the households invest in their children as a human capital. In addition, contributing factors to households' human capital investment was examined. The results of this study are as follows; First, Average number of children 2 children of surveyed housewives, full time housewives had more time spent for children than working counterparts. The former spent 6.8 hours a day with the latter 4.98 hour a day while both of them shared the most time in nonphysical care of their children. meanwhile, money paid for children was that full time housewife family spent 1,014,000 and a working housewife family paid 974,000. Second, In the full time housewives, total amount of time housewives spend for their children was greatly influenced by the income, the age of the youngest child, and emotional value. The housewives' educational level, life cycle, and an income were a significant impact on money investment. Total investment was influenced by the housewives' educational level, life cycle, income, and the number of children.

• Asian Pacific Journal of Cancer Prevention
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• 제17권4호
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• pp.1891-1898
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• 2016

Imperata cylindrica, a tall tufted grass which has multiple pharmacological applications is one of the key ingredients in various traditional medicinal formula used in India. Previous reports have shown that I. cylindrica plant extract inhibited cell proliferation and induced apoptosis in various cancer cell lines. To our knowledge, no studies have been published on the effect of I. cylindrica leaf extract on human oral cancers. The present study was undertaken in order to evaluate the anticancer properties of the leaf extract of I. cylindrica using an oral squamous cell carcinoma cell line SCC-9 as an in vitro model system. A methanol extract from dried leaves of I. cylindrica (ICL) was prepared by standard procedures. Effects of the ICL extract on the morphology of SCC-9 cells was visualized by microscopy. Cytotoxicity was determined by MTT assay. Effects of the ICL extract on colony forming ability of SCC-9 cells was evaluated using clonogenic assay. Cell cycle analysis was performed by flow cytometry and induction of apoptosis was determined by DNA fragmentation assay. The ICL extract treatment caused cytotoxicity and induced cell death in vitro in SCC-9 cells in a dose-dependent manner. This treatment also significantly reduced the clonogenic potential and inhibited cell proliferation by arresting the cell cycle in the G2/M phase. Furthermore, DNA fragmentation assays showed that the observed cell death was caused by apoptosis. This is the first report showing the anticancer activity of the methanol extracts from the leaves of I. cylindrica in human oral cancer cell line. Our data indicates that ICL extract could be considered as one of the lead compounds for the formulation of anticancer therapeutic agents to treat/manage human oral cancers. The natural abundance of I. cylindrica and its wide geographic distribution could render it one of the primary resource materials for preparation of anticancer therapeutic agents.

• Journal of Photoscience
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• 제10권2호
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• pp.195-198
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• 2003

In the cellular response to DNA damaging agents, cells undergo cell cycle arrest or apoptosis against irrepairable DNA damage. RpS3 is known to function as UV DNA repair endonuclease III and ribosomal protein S3. In this study, we used normal and rpS3-overexpressed 293T cells to examine the role of rpS3 in response to DNA damaging agents. When 293T cells transfected with rpS3 were irradiated with UV, the pattern of cell cycle was dramatically changed in comparison with un-transfected 293T cells. We also found that the expression of rpS3 in normal cells was increased by treatment with DNA damaging agents. By means of Western and Northern blot analyses in rat tissues, we showed the expression pattern of rpS3 protein and its mRNA. These data suggest that DNA repair and cell cycle arrest are interrelated to each other through rpS3, and the increased expression of rpS3 seems to regulate the cell cycle arrest by DNA damaging agents.

• 한국안전학회지
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• 제22권2호
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• pp.59-66
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• 2007

As the need of handling heavy materials increases, various cranes are used in industries. However, the effectiveness of crane also entails industrial accidents such as falling, constriction etc. In fact, the number of fatal accidents caused by crane is still high in Korea. To find out the causes of the accidents in terms of human error, we developed a man-machine system model that consists of two axes; human information processing and crane life cycle. In the human information processing dimension, we simplified it as five functions; sensing and perception, decision making and memory, response etc. In the crane life cycle dimension, we divided it into nine phases; design, production, operation etc. For the 152 fatal accident records during 1999-2006 years, we classified them into 45 cells made by two axes. Then we identified the preceding causes of the classified crane accident based on performance shaping factors. As the results of statistical analysis, the overall trend of crane fatal accidents was described. For the cause analysis, wrong decision making in work plan phase shows the highest frequency. Next, the poor information input in crane operation followed in accident frequency. In ergonomics view, the problems of interface design in displays and controls made 11.8% of fatal accidents. Following the analysis, several ergonomic design guidelines to prevent crane accidents were suggested.

• 디자인학연구
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• 제12권2호
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• pp.97-106
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• 1999

환경오염이라는 인류의 총체적 위기는 인간 중심적 패러다임을 인간과 자연의 공존을 목표로 하는 생태학적 패러다임으로 변화시켰고, 이에 따라 디자이너 역시 인류의 과제인 환경문제 해결에 동참하지 않을 수 없게 되었다. 이러한 사회적 책임과 디자이너 자신의 윤리적 책임은 디자인 방향을 환경을 위한 디자인(Design For Environment)으로 전환하게 하였다. 본 연구는 디자인을 통한 환경 문제 해결이라는 측면에서 그 하나의 실마리를 제공하는 것에 그 목적이 있다. 즉, 제품의 조형에서 내구적 속성을 파악하여 이를 제품에 부가함으로써, 경제적 손실과 환경오염을 줄이는데 기여할 수 있을 것이라는 것이다. 제품의 형태를 결정짓는 디자이너의 입장에서 제품 조형의 내구적 속성을 파악하여 이를 제품에 부여한다는 것은 제품의 수명(Product Life Cycle)을 연장시키는 데 도움을 줌으로써, 제품의 폐기를 유보시킬 수 있을 뿐 아니라 제품이 제 수명을 다하기도 전에 새로운 형태의 제품에 밀려 폐기되는 일을 감소시켜 과잉 생산에서 오는 에너지 낭비와 자원의 소모를 막고, 오염물질의 방출과 쓰레기를 줄여 환경오염을 최소화시킬 수 있는 것이다. 이것은 기본적으로 기업의 과도한 경쟁 의식에 의한 무분별한 제품개발과 소비자의 소비 지향적인 태도에 반발하는 것이다. 이 가정 위에서 제품 조형의 내구적 속성을 밝히는 것이 이 논문의 궁극적 목표라 하겠다.

• 한국주거학회논문집
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• 제21권3호
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• pp.115-124
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• 2010

The environment which has been destroyed for the national growth since 1960's would seem to offer infinite resources to human, but now, the existence of human being is threatened by the development thoughtless for the environment. The World Powers have concentrated on green growth with eco-friendly resource since the end of 20th century. Korea suggested that the vision was the low carbon for green growth in 2008. It is necessary to supply Long-Life Housing in the green technology in terms of the sustainable housing development based on various life style, life cycle of the residences, the restrain remodeling and redevelopment in construction. This study is aim to establish the development of maintenance process to make continuous inhabitation of Long-Life Housing that has the separated SI for maintenance, durability, variability and remodeling. The maintenance for Long-Life Housing is very important to have more than 50~70 years the long term of life cycle in comparison with Housing. Also, the roles of manager and user are important parts in Long-Life Housing. The present maintenance for Housing is shift and repair works by the routine maintenance and demage. However, The maintenance for Long-Life Housing should consider movement and flexibility. In addition, Long-Life Housing requires the proper process of maintenance because it is different from Housing in housing concept, design and constructions stage. Therefore this study shows the efficient maintenance process for Long-Life Housing.

• 대한인간공학회지
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• 제27권1호
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• pp.37-43
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• 2008

A lot of models have been developed for prevention of human errors. Nevertheless most of them failed to attract attention of industry which has been looking for an integrative model that can show practical countermeasures as well as causal factors of human errors. This research aimed to develop a comprehensive model that can mainly be applied to industrial fields. Therefore, in the model, it was tried to explain sequences of an operator's information process that might cause human errors on one hand, and life cycle stages of facilities involved when human errors occur on the other hand. This model was validated by using a typical accident case. With the comprehensive model presented in this research, one could follow up the sequence of human errors caused by operators, and errors made at the design stage which might cause accidents could be tracked. As a consequence, it is expected that much attention would be paid to preventing human errors in industrial fields since safety personnel can easily find out cause of human errors throughout life cycle stages of man-machine facilities if utilizing the suggested model.

• 한국기계가공학회지
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• 제14권1호
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• pp.1-8
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• 2015

Productivity of machining using machine tools is affected by cutting conditions such as cutting speed, feedrate and depth. However, undesirable conditions that lengthen the machining cycle and shorten the tool life occur frequently because determination of cutting condition is known to depend on human experience. This paper presents a method of cycle reduction by removing undesirable conditions. For cycle reduction, maximum cutting load is determined using commercial FEM simulation code. The feedrate in the NC program is altered based on a predetermined cutting load value. To make a decision on the proposed effectiveness, a simulation is performed for the brake hub parts of an automobile. From the evaluation, it was found that the cycle reduction was under 15%.

• Molecules and Cells
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• 제24권3호
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• pp.424-430
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• 2007

The biological effects of low-dose radiation have been investigated and debated for more than a century, but its cellular effects and regulatory mechanisms remain poorly understood. This study shows the human cellular responses to low-dose radiation in CCD-18 Lu cells, which are derived from normal human lung fibroblasts. We examined a colony-forming assay for cell survival by ionizing radiation. Live cell counting and cell cycle analysis were measured for cell proliferation and cell cycle progression following low-dose irradiation. We examined Raf and Akt phosphorylation to determine the proliferation mechanism resulting from low-dose radiation. We also observed that p53 and p21 were related to cell cycle response. We found that 0.05 Gy of ionizing radiation enhanced cell proliferation and did not change the progression of the cell cycle. In addition, 0.05 Gy of ionizing radiation transiently activated Raf and Akt, but did not change phospho-p53, p53 and p21 in CCD-18 Lu cells. However, 2 Gy of ionizing radiation induced cell cycle arrest, phosphorylation of p53, and expression of p53 and p21. The phosphorylation of Raf and Akt proteins induced by 0.05 Gy of ionizing radiation was abolished by pre-treatment with an EGFR inhibitor, AG1478, or a PI3k inhibitor, LY294002. Cell proliferation stimulated by 0.05 Gy of ionizing radiation was blocked by the suppression of Raf and Akt phosphorylation with these inhibitors. These results suggest that 0.05 Gy of ionizing radiation stimulates cell proliferation through the transient activation of Raf and Akt in CCD-18 Lu cells.

• Environmental Engineering Research
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• 제25권1호
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• pp.52-61
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• 2020

The article examines the impact differences between producing concrete and asphalt. Both materials are widely used in the construction industry. Construction activities account for a large portion of greenhouse gases. Therefore, it is important to consider the Life Cycle Analysis (LCA) to reduce environmental impacts. In this study, the material processes were inputted into an LCA program called SimaPro. The database used for the study was Ecoinvent as it is one of the major databases within SimaPro. The materials were compared against impacts per kg of material produced as the functional unit. Each process was created using the materials, energy and transportation required to produce the materials. Waste streams were also included in the process to determine the impacts after the product was done with its useful life. Using the ReCiPe method, an LCA was conducted. Midpoint and endpoint categories were examined for both the productions. The processes had similar results for the human health and ecosystems categories; however asphalt was marginally higher for both. Asphalt had exceeded concrete in the resource impact category by 100 mPt. The results indicate that concrete is the more sustainable building material. Determination of various impacts of the materials is important for material selection.