• Journal of Korean Association for Spatial Structures
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• v.23 no.2
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• pp.61-68
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• 2023

A two-hour fire-resistance PC hollow slab for residential use was developed to secure structural and fire-resistance performance and to be applied to the general building and apartment housing markets. Compared to the existing hollow slab, in order to secure the same or better structural performance and economic feasibility by reducing the quantity, it was attempted to secure the fire resistance performance by reducing the concrete filling rate in the cross section and adjusting the thickness of the upper and lower flanges by optimizing the hollow shape in the cross section of the slab. For structural performance evaluation, experiments were performed on PC hollow slabs by varying the member thickness and the presence or absence of overlaid concrete, and all of the experimental results showed that the design strength was sufficiently exhibited and that stability during construction was possible. The developed synthetic PC hollow slab has secured fire resistance and residential performance so that it can be applied to all buildings, and it is intended to be immediately applied to the field.

• Journal of the Korea Concrete Institute
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• v.20 no.1
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• pp.43-50
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• 2008

This paper presents experimental and analytical results on the long-term behavior of the reinforced recycled aggregate concrete beams under sustained loading. In this experimental program, three beams with different conditions of aggregates replacement (natural aggregate 100%, recycled coarse aggregate 100%, recycled fine aggregate 50%) were subjected to the sustained flexural loading that was a half of the nominal flexural capacity over a period of 1 year. The beam were designed with net span of 2,000 mm and rectangular cross-section of 170 mm width and 170 mm effective depth. The beams were instrumented and monitored to observe the change in the long-term behavior due to creep and shrinkage of concrete under sustained loading. The predictions of long-term deflection by ACI code, Branson, Mayer, Neville, EMM and AEMM were compared with the experimental results. From the experimental results, the reinforced concrete beams with recycled aggregates showed the same performance as that of a beam with natural aggregate. The proposed method to predict the long-term deflections of reinforced recycled aggregate concrete beams gives a good estimation for experimental results.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.7
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• pp.3341-3355
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• 2016

Background: A recent WHO data report on mortality attributable to tobacco use including cigarette smoking indicated a very high burden of deaths in Asia and that people often initiate smoking as early as young adolescents. The objectives of this study were to systematically review peer-reviewed articles on cigarette smoking initiation among Asian adolescents and to develop a conceptual model of factors influencing smoking initiation by integrating all relevant factors based on existing data. Materials and Methods: Following a PRISMA guideline, a systematic review of articles published between 2005 and June 2015 was conducted using 5 databases on cigarette smoking initiation among adolescents (aged 10-19 years) living in Asia. We summarized the main findings of each study according to our research questions and data that emerged during the data extraction process. Analysis and categorization were based on the TTI and TPB models and classification of factors extracted from the study, were as follows: personal factors, social factors, broader environmental factors, mediators, and intention to initiate smoking and smoking behavior. Results: Of 1,227 identified studies, only 20 were included in this review. Our findings found that the mean age of cigarette smoking initiation ranged from 10 to 14 years and those who are more likely to initiate smoking are male, older adolescents, adolescents with low parental SES, individuals with low parental monitoring, low parental education level and having no discussion on smoking at home, those living in public housing and those exhibiting health-risk behavior. Our study also revealed that the risk of smoking initiation increased when they are exposed to smokers, influenced by peers, exposed to tobacco advertisements, receive pocket money, have lack of knowledge about smoking, have poor school performance, have a family conflict and have psychological problems. The conceptual model developed demonstrated complex networks of factors influencing initiation. Conclusions: This systematic review presents various factors influencing smoking initiation of the Asian adolescents and provides a conceptual framework to further analyze factors. Future studies should have a standard measure of smoking initiation, should analyze interactions and the intensity of relationships between different factors or variables in the conceptual model. This will in turn consolidate the understanding of the different factors affecting smoking initiation and will help to improve interventions in this area.

• Fire Science and Engineering
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• v.32 no.5
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• pp.112-121
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• 2018

In the present study, a group of subjects consisting of "Fire Professional Engineers" was selected to examine the effects of life safety awareness and safety behaviors of the subjects on life safety through an analyses of the descriptive statistics, factors, reliability, and correlation; simple regression and three-stage regression analyses on mediation were also carried out based on the hypotheses developed. The results showed that the degree of safety behavior increased by 72.1% in accordance with the increased safety awareness of fire professional engineers; the life safety was also increased by 61.5% and 64.5% by the increases in safety awareness and safety behavior of fire professional engineers, respectively. In addition, the safety behaviors demonstrated a partial mediatory effect in the relationship between safety awareness and life safety. All hypotheses (H1, H2, H3, H4), established for the present study, were accepted based on statistical verifications that justified an amendment of the Acts pertinent to firefighting service focusing on life safety; the data are expected to be exploited to reflect significance of life safety.

• Journal of the Society of Disaster Information
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• v.19 no.1
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• pp.161-172
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• 2023

Safety education delivered to construction workers in a lecture manner has limitations in concentration and immersion, so delivery power and interest are low. In order to improve unstable behavior through education and prevent safety accidents, it is necessary to change the paradigm to hands-on education. Purpose: Experiential safety education aims to contribute to preventing accidents for construction workers by quickly recognizing risks, improving emergency response skills, and verifying the effectiveness of pre- and post-learning. Method: Based on a survey of workers who experienced the same work environment as the actual construction site, an opinion survey on the pre- and post-safety experience education and a variable measurement tool were planned, and a research hypothesis was established. Results: The Bayesian theory and MC simulation analysis were used to analyze the structural equation model, and the change in construction worker behavior was confirmed through the intended safety (A), non-experiential education in the sub-area of anxiety (B), average, standard deviation, and minimum and maximum values. Conclusion: The effect of education and industrial accidents are reduced only when construction workers are motivated to participate.

• Journal of Consumption Culture
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• v.15 no.1
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• pp.93-118
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• 2012

The purpose of this study was to examine the effect of a householder's working type on household saving from the perspective of precautionary saving behavior theory and the determinants of household saving by householder's working type. The data for this study was from the 2009 year of the Korea Welfare Panel Survey (KOWEPS), consisting of 2,463 households with householders whose working type was regular or non-regular employment(temporary, daily or public work). OLS regression analyses and Chow-tests were performed. In the regression analyses, the dependent variables for household saving were precautionary saving and precautionary asset. Precautionary saving was operationalized with the amount of average monthly saving and the ratio of average monthly saving to average monthly disposable income, and precautionary asset was operationalized with the amount of financial assets and the ratio of financial assets to net assets. The independent variables were household income, household assets, householder's working type(regular, non-regular), householder's age, sex, education level and marriage status, income level, the number of household members, housing type, debt, and public transfer income. Monthly average total consumption expenditures for household income, and net assets for household assets, the existence of spouse for marriage status, poverty for income level were used. Public transfer income was classified into three, social insurance, basic assistance and government assistance. For the analyses, Stata 11.0 version was used. The results are as follows: Householder's working type was significantly related to the precautionary saving behavior of a household. However, the precautionary saving and the precautionary asset of a household with a householder in non-regular working type was lower than those of a household with a householder in regular working type. This result is not consistent with the expectation from the perspective of precautionary saving behavior that the saving of a household with a householder in non-regular working type is expected to be higher than that of a household with a householder in regular working type. According to the analyses of the determinants for precautionary saving behavior by householder's working type, monthly average total consumption expenditures, debt, net assets, poverty, the number of household members, basic assistance were statistically significant variables. The positive relation of basic assistance to precautionary saving(the amount of average monthly saving and the ratio of average monthly saving)is a noteworthy result in the analyses of the determinants for household saving by householder's working type. The above results suggest the followings. First, it is easy to predict the unstability of economic life of a household with a householder in non-regular working type because of relatively low precautionary saving and precautionary asset. The reason for the low precautionary saving and the low precautionary asset may be a low current income of the household in spite of its willingness to save. If this reasoning is possible, it suggests that policies are needed for households with householders in non-regular working type to save. Second, the relatively low precautionary saving and precautionary asset of a household with a householder in non-regular working type suggest also their long-term economic stability. This suggests they need to try a long-term financial planning even though they have limitations to save for future because of their low current income. It is necessary to develop the financial planning for the households with unstable incomes. Third, the determinants for precautionary saving behavior by householder's working type were mostly the ones which reflect the economic condition of a household. This suggests that the economic condition of a household is a core factor for household saving. Consequently, it emphasizes the efforts for a household to acquire the adequate level of income for saving. Forth, the positive relation of basic assistance to precautionary saving(the amount of average monthly saving and the ratio of average monthly saving) suggests the possibility for a household to accumulate the precautionary saving and the precautionary asset in the channel of basic assistance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.12
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• pp.232-241
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• 2016

Among city parks, children's parks are more accessible than other parks in the city, and there are many users. They are used not only for children's playgrounds, but also for relaxation and leisure spaces for local residents. On the other hand, as a result of focusing on the quantitative increase by the engineering division by the Urban park Act, the consideration of the users of various classes is insufficient. The purpose of this study was to analyze the actual use of children parks in single - family housing and communal housing areas, and to identify the problems and future directions of the use of children parks. For this purpose, a case study and a document survey were conducted. First, through scholarship research, the theoretical review and the present situation were summarized based on the data, such as the papers and research reports related to the existing children's park. The status of the location, facilities and management were then identified through interviews and site visits with the children's park management staff. As a result, the children's park was utilized as a leisure space with high accessibility in the living area. As a result, the residence time of most users was within 1 hour to 2 hours. In particular, use by elderly people was higher than the use by children. Therefore, it would be desirable to design the future planning of the children's parks and to plan the arrangement in accordance with the future - oriented multi - purpose neighborhood type children's park.

• Journal of the Korean Geotechnical Society
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• v.29 no.8
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• pp.37-51
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• 2013

An energy pile encases heat exchange pipes to exchange thermal energy with the surrounding ground formation by circulating working fluid through the pipes. An energy pile has many advantages in terms of economic feasibility and constructability over conventional Ground Heat Exchangers (GHEXs). In this paper, a coil-type PHC energy pile was constructed in a test bed and its thermal performance was experimentally and numerically evaluated to make a preliminary design. An in-situ thermal response test (TRT) was performed on the coil-type PHC energy pile and its results were compared with the solid cylinder source model presented by Man et al. (2010). In addition, a CFD numerical analysis using FLUNET was carried out to back-analyze the thermal conductivity of the ground formation from the Ttype PHC energy RT result. To study effects of a coil pitch of the coil-type heat exchange pipe, a thermal interference between the heat exchange pipes in PHC energy piles was parametrically studied by performing the CFD numerical analysis, then the effect of the coil pitch on thermal performance and efficiency of heat exchange were evaluated. Finally, an equivalent heat exchange efficiency factor for the coil-type PHC energy pile in comparison with a common multiple U-type PHC energy pile was obtained to facilitate a preliminary design method for the coil-type PHC energy pile by adopting the PILESIM2 program.

• Korean Journal of Occupational Health Nursing
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• v.9 no.2
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• pp.94-109
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• 2000

The chances of disease pattern increased the importance of Health-promoting Lifestyle and a large part of the Health-promoting Lifestyle is associated with individual's habit. Health-promoting Lifestyle among nurses is very important because nurses could be a role model of patients and possibly influence many patients. The purpose of this study was oat on1y to assess how hospital nurses practice their Health-promoting Lifestyle but also to identify those affecting determinants. The subjects were 392 nurses working at 3 different hospital in Seoul. These data were collected by self administered questionnaire from April 27 to May 20, 2000. This study examined Health-promoting Lifestyle using In Sook Park's model, individual characteristics. Behavior-specific Cognitions and Affect factors using Pender's model and tried to fine out their relationships. The instruments used in this study were Health-promoting Lifestyle Profile developed by In Sock Park(1995). Likert's four-point scale was used also in this research. The percentage, mean standard deviation, AVNOVA, Pearson's correlation coefficient and multiple regression in the SAS package were used to analyze the data. The results of this study were as follows; 1. 52.3% of sample were aged between 25 and 29, 67.1% were single, 55.6% were university graduates, 51.8% earned 1.5 to 2.0 million won, 57.9% slept for d to 8 hours, 74.5% stated they were healthy. 2. 32.7% of sample worked in surgical gird department, 82.4% worked in 3 shift, 26.3% have been working as nurses for 5 to 7 years. Average score of Perceived self-efficacy was 3.63, Perceived benefits of action was 3.25, Social support was 2.75, and Perceived barriers to action was 1.87 which was the lowest score. 3. The average score if the performance in Health-promoting Lifestyle variable was 2.45 which was lower than previous study. The sanitary life Was 3.18 which was the highest score, harmonious relationship 3.13, emotional support 2.90. The variable with the highest degree of performance was the sanitary life, whereas the one with the west degree was the health diet. 4. There were no significant difference in perceived benefits of action with individual's a character, but in Perceived bait his of action there were significant differences with age(p<.01), marital status(p<.05), housing(p<.05), and Perceived health status(p<.05). In Perceived self-efficacy, there were significant differences with educational level(p<05), sleeping hours(p<.05), and BMI(p<.05). In Social support here were significant difference with housing and sleeping hours.

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.349-359
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• 2011

The consolidation behavior of soft clay is controlled mainly by its compressibility and deformation characteristics. Soil permeability depends on various soil characteristics, including the soil type and anisotropy. The coefficient of permeability of soft clay is determined by using a laboratory test (the Oedometer test) or a piezocone test. The latter test is useful for estimating the permeability characteristics from $c_h$ and $k_h$ by performing an excess pore-pressure dissipation test. This study seeks to validate an existing theoretical formula in applying it to marine clay, and to assess the relation between $k_h/k_c$ and the mechanical properties of soft clay. Piezocone tests and laboratory tests were performed using sediment from the Yellow Sea and from the South Sea near Korea. We compared $k_h/k_v$ values obtained using the piezocone test and using laboratory consolidation tests. The obtained values are similar to the values obtained by Jamiolkowski et al. (M application); therefore, the latter values are recommended to be used as $k_h/k_v$.