• Journal of the Korean Geotechnical Society
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• v.18 no.4
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• pp.339-347
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• 2002

An in-situ experiment was performed to evaluate the pullout resistance capacity of chains which is used as a reinforcement of reinforced earth wall. It was also considered that chain was combined with a bar or L-type steel angle by the transverse reinforcement member in the experiment. About 80 pullout tests were peformed with varying the lengths of chain(2.0m, 2.5m, and 3.0m), the combination of each transverse members(chain only, chain＋bar, or chain＋angle), and the vertical placement of reinforcements. In the case that uses a chain only and a chain combined with bar, the maximum displacement was about 150mm and load continuously increased to the ultimate tensile strength of chain, and then tension failure of chains occurred. But in the case of a chain combined with angle, the displacement decreased to about 100mm and so it was expected that this combination can constrain the displacement of chain. On the other hand, comparing the yielding pullout load measured in the field to that calculated by theoretical equation, it is shown that measured values are 1.2~3.0 times greater than those of calculated values according to the length of chain, normal vertical stress, and the combination of chain with transverse members. However, the difference in the increment of yielding pullout load between bar and angle is not clear but it appears almost the same increment. It is expected that chain can be safely used as reinforcements of reinforced earth wall, although a theoretical estimation of the pullout resistance capability of chain is too conservative.

• The Korean Journal of Community Living Science
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• v.27 no.2
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• pp.245-263
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• 2016

This study was conducted to investigate the thermoregulatory behavior of young males in terms of self-identified thermal tolerance. We recruited 436 male students from Seoul ($24.0{\pm}4.6yr$ in age, $175.3{\pm}5.5cm$ in height, $70.1{\pm}10.6kg$ in body mass, and $23.0{\pm}2.7$ in BMI) in accordance with four types of self-identified thermal tolerance: 1) tolerable of both cold and heat, BCH (N=15); 2) heat tolerable only, HTO (N=118); 3) cold tolerable only, CTO (N=162); and 4) neither cold nor heat tolerable, NCH (N=141). The questionnaire consisted of 55 questions regarding preference to cold or heat environment, seasonal thermoregulatory behaviors including clothing habits, seasonal sleeping environments, health care/physical fitness, and anthropometric items. The results showed that: 1) BCH preferred less auxiliary heating devices, gloves/hats, or thermal underwear in winter and had very few experiences with cold/heat injuries or catching a cold, whereas NCH showed the opposite behavior and experiences as BCH; 2) thermoregulatory behaviors were not symmetrical between summer and winter. Most male students preferred cold beverage/foods to using cooling devices to lower body temperature in summer, whereas auxiliary heating devices were preferred to warm beverage/foods to maintain body temperature in winter; 3) thermoregulatory behaviors of NCH had more items in common with HTO than CTO, while the behaviors of BCH were more closely related to CTO than the behaviors of BCH were more closely related to CTO than HTO. Overall, we confirmed that thermoregulatory behaviors were apparently classified by self-identified thermal tolerance, and such behaviors could be adjusted by improving cold or heat tolerance.

• Korean Journal of Community Nutrition
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• v.18 no.4
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• pp.386-401
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• 2013

This study was conducted to analyze traditional aspects of school lunch menus in Korea. We conducted a content analysis of menu-related contents included in guidelines for school lunch programs provided by 16 city and provincial education offices. In addition, the data of 10,495 menus for the third week of December 2010 and March, July, October 2011 from 557 elementary, middle, and high school were analyzed by school grade, area, and province. The results showed that there were no specific and detailed guidelines for menu planning in terms of traditional food culture in most of the guidelines for school lunch programs. However, the basic traditional menu composition was maintained in school lunch menus. The percentage of menus including rice and Kimchi was 97% and 95%, respectively, and that including Korean soup was about 72%. However, the frequency of serving Namul, Korean seasoned vegetable dish, accounted for only about 52% of the menus. The percentage of the menus following the traditional food group pattern including such five food groups as rice, Korean soup, Kimchi, Namul, and optional Korean side dish was only about 35%. The percentage of the menus following the traditional food group pattern excluding Namul from the five food groups accounted for about 30%. The traditional food group score, calculated by allocating 1 point to each of the five food groups was 4.06 out of 5 points on average. Elementary schools and schools in rural area and in Jeolla-do province served traditional menus more frequently. In conclusion, school lunch programs need to consider establishing traditional foods-based standards and relevant guidelines for school lunch, particularly for high schools and schools in urban areas and in some provinces.

• Journal of Korean Tunnelling and Underground Space Association
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• v.21 no.6
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• pp.749-762
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• 2019

In recent years, in urban areas, underground of roads are being promoted in order to resolve traffic congestion and to secure green spaces, and due to the low ratio of large vehicles, they are planned or constructed as road tunnels for small cars only. In addition, the tunnels being built in the city is a tendency to be enlarged to play the role of main roads. Accordingly, the capacity of the ventilation system is increasing and various ventilation methods are required, and the importance of maintenance after the completion of the tunnel such as the operating cost of the ventilation system is emphasized. Therefore, the need for optimization of the operation stage for reducing the power consumption of the ventilation system and the study of the ventilation system operation control logic is increasing. In this study, the study on the necessity of the optimization of operation stage and control logic of the ventilation system was carried out to realize the energy-saving operation for the small car only passing through tunnels which is applied of ① jet fan and combination ventilation system (② jet fan + air purifying equipment, ③ jet fan + vertical shaft, ④ jet fan + supply air semi-transverse). As a result of this study, there can be various operating combinations in the case of the combined ventilation system, and even though the amount of ventilation air is the same, the operating power varies greatly according to the operating combinations. It was found that operating the axial fan first rather than the jet fan first operation method has an effect on power saving.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2597-2606
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• 2014

Background: There is a scarcity of information about the proportion of the adult Saudi population that meet the recommended guidelines of physical activity (PA) to reduce cancer risk. Moreover, their awareness about the role of PA in cancer prevention is unclear. Objectives: This cross-sectional study aimed at estimating the proportion of adult Saudis meeting the PA guidelines, specifically those recommended by American Cancer Society (ACS) for cancer prevention, and to assess the public awareness about the role of PA in cancer prevention. Materials and Methods: Using a multistage sampling method, 2,127 adult Saudis of both genders were recruited from 6 urban and 4 rural primary health care centers in Al Hassa, Saudi Arabia. Participants were personally interviewed to gather information about their sociodemographic characteristics, searching activity about PA and cancer, and the time spent in leisure time PA (moderate and vigorous)/week using the Global Physical Activity Questionnaire with show cards. Finally, items about the role of PA in cancer risk reduction were inquired. Results: Of the included participants, 11.6% met the recommendations for cancer prevention (${\geq}45$ minutes of moderate-vigorous PA activity/${\geq}5$ days/week or 225 minutes/week). Multivariate regression showed that being male (AOR=1.49, CI=1.09-2.06), <20 years of age (AOR=3.11, CI=2.03-4.76), and unemployed (AOR=2.22, CI=1.57-3.18) were significant predictors for meeting PA recommendations for cancer prevention. Only 11.4% of the sample indicated correctly the frequency and duration of PA required for an average adult to be physically active and while >70% of them indicated the role of PA in prevention of hypertension, coronary heart disease and lowering elevated blood cholesterol, only 18.6% and 21.7% correctly mentioned the role of PA in reducing colon and breast cancer risk, respectively. Poor knowledge was found among those with less than college education and aged ${\geq}50$ years. The level of knowledge was significantly positively correlated with total leisure time PA of the participants. Conclusions: A minority of adult Saudis in Al Hassa was aware about the role of PA in cancer prevention and engaged in sufficient LTPA for cancer risk reduction benefits, highlighting the need for public health actions to include policies and programs that address factors deterring their participation in LTPA and increasing their awareness with remedies to manage the prevalent misconceptions.

• Geophysics and Geophysical Exploration
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• v.9 no.1
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• pp.102-107
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• 2006

Recently, rapid developments in computer hardware have enabled reverse-time migration to be applied to various production imaging problems. As a wave-equation technique using the two-way wave equation, reverse-time migration can handle not only multi-path arrivals but also steep dips and overturned reflections. However, reverse-time migration causes unwanted artefacts, which arise from the two-way characteristics of the hyperbolic wave equation. Zero-lag cross correlation with diving waves, head waves and back-scattered waves result in spurious artefacts. These strong artefacts have the common feature that the correlating forward and backward wavefields propagate in almost the opposite direction to each other at each correlation point. This is because the ray paths of the forward and backward wavefields are almost identical. In this paper, we present several tactics to avoid artefacts in shot-domain reverse-time migration. Simple muting of a shot gather before migration, or wavefront migration which performs correlation only within a time window following first arriving travel times, are useful in suppressing artefacts. Calculating the wave propagation direction from the Poynting vector gives rise to a new imaging condition, which can eliminate strong artefacts and can produce common image gathers in the reflection angle domain.

• Journal of Agricultural Extension & Community Development
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• v.20 no.2
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• pp.407-429
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• 2013

Although rural areas account for more than 80% of the total land area of South Korea, most of them are deteriorated and living environment is inconvenient. In addition, the migration of young generation to urban areas and ageing have reduced the population and caused not only cavitation phenomena of villages but also stagnant communities. As for one of the rural areas, the seat of Myeon Office located in Oesan-myeon, Buyeo-gun, Chungcheongnam-do, this study presented not a plan only for strengthening hub functions but the methodology of the complex development plan in consideration of the regional characteristics in the comprehensive improvement project in seat of Myeon Office. From the perspective of enhancing the function of the seat of Myeon Office, it is inevitable to establish plans based on hardware. However, empowerment of the residents in the targeted areas also works as an important factor. In other words, each project promoted by the plan will be mainly operated by the local residents. Therefore, it is necessary to establish a management system of this. The success or failure of the established plan is based on the accurate survey of the issues of the targeted areas and demand, and this depends on participation and positive response of the residents of the targeted areas. That is, the method as a 'local community network' is required in order to increase the effect of resident participation in the planning area.

• Journal of Korea Spatial Information System Society
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• v.9 no.3
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• pp.17-24
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• 2007

The noise problem is one of the major problems associated with large cities and is considered important factor not only in maintenance but also in development of cities. Accordingly, the noise map is being increasingly used in city planning and design. However, the existing two-dimensional noise maps only show regional, planar distribution of noise. This study presented a method to build a data model for analyzing and visualizing noise levels at fine scale considering the vertical distribution of noise in a building. By expanding the 2D topology concept used in conventional GIS to 3D, it suggested a 3D GIS data model that makes 3D spatial queries, analyses and visualization possible and applied the proposed approach to building a 3D noise information system. By building and testing the system, the study showed different functionalities including 3D spatial queries and 3D visualization of noise levels varying temporally or according as the height of sound-proof walls. In each case, the population exposed to noise was quantitatively computed to illustrate the potential in the areas of city planning and design.

• Journal of the Korean Society of Safety
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• v.15 no.2
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• pp.111-117
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• 2000

In this study, the bearing capacity behavior of strip footing located above a continuous cavity in sand was investigated experimentally. The model footing test was performed in a model box made by using raining method in sand. The model footing test results were compared with those obtained from theoretically proposed equations. The results of the analysis indicate that there is a critical region under the footing. For strip footing, there exists a critical depth below which the presence of the cavity has negligible influence on the footing performance. Only when the cavity is located within this region will the footing performance be significantly affected by the presence of the cavity. The size of the critical region depends on several factors such as footing shape, soil property, cavity size and cavity shape. When the cavity is located within the critical region, the bearing capacity of the footing varies with various factors, such as the size and location of the cavity and the depth of foundation. Based on the experimental study, the following conclusions were induced. 1. The ultimate bearing capacity due to the eccentricity of a underground cavity increases at the rate of the small rather than that due to the depth of a underground cavity. This indicates that the bearing capacity of a strip footing is influenced on the depth rather than the eccentricity of a underground cavity. 2. The critical $depth(D/B)_{cr}$, by underground cavity in sand soil ground that is made by the relative density($D_r$)=55%, 65%, 75%, approaches a range of about 8~10 in case of W/B=1, and about 11~13 in case of W/B=2. 3. In case of the relative density($D_r$) 75%, the most outstanding differential settlement trend is shown in the depth of 4~8cm regardless of the size of cavity, namely, when the value of D/B is 1~2. Therefore, a underground cavity influences on not only the decrease of the bearing capacity but also the differential settlement of a strip footing.

• Korean Journal of Community Nutrition
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• v.11 no.4
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• pp.469-478
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• 2006

In order to investigate the adolescent's beverage drinking pattern and its related ecological factors, a questionnaire survey was conducted with the subjects of 920 middle and high-school students,450 boys and 470 girls, residing in 4 cities of the Chungnam area. Of the subjects 65% liked, or liked very much, beverages and only 3.7% did not like beverages. They drank beverages 4.3 $\pm$ 4.0 times a week on average, but 10.4% of them drank beverages more than twice a day. Male students drank more frequently than the females. The intake frequency of carbonated drinks was 1.7 $\pm$ 2.3 a week which was about 40% of the total beverages. However, more students drank mainly ion beverages (33.6%) than carbonated drinks (28.7%). As the students took more balanced food and ate more regularly, their beverage drinking frequency decreased and those taking carbonated drinks also tended to decrease. The more frequent the students took fast food, the more frequent they drank carbonated beverages. The drinking frequencies for beverages or carbonated beverages were also less in students eating cooked rice with sidedishes as breakfast than in students eating others. The drinking frequency for carbonated drinks showed significant correlations with the students' activities such as the time spent using computers and watching TV got longer, the drinking frequency for soft drinks was also higher. When nutritional knowledge was higher, drinking frequency for carbonated drinks got lower. In conclusion, to make the adolescents improve their attitudes toward drinking beverages and to prevent excessive drinking of carbonated drinks, they should be educated not only on the nutritional knowledge and the proper intake of beverages, but also on good dietary habits including balance, regularity, and types of meals. Proper snacking and fast food consumption also should be taught. Since ion beverages were taken more frequently than carbonated drinks among adolescents, further study is recommended on the impact of excessive intake of ion beverages.