• The Journal of Korean Society for School & Community Health Education
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• v.6
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• pp.1-16
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• 2005

This study was conducted to the middle and high school students in some Seoul and Kyunki areas to identify the smoking behavior characteristics among adolescences. A self-administered survey was conducted to the 2nd grad students in 4 middle schools and 6 high schools and the survey Questionnaire included general characteristics, smoking and drug use history, the close people's smoking and drug use, smoking and drug abuse prevention education, smoking intention, and smoking attitude. A total of 2,452 youths finished the survey (1,182 middle school students and 1,270 high school students). Current smoking students were 14.6%, the ex-smokers were 5.5%, and the never smokers were 85.4%. Majority of students smoked less than 5 bars of cigarettes and their first smoking experiences were related to their family members (siblings, parents, and relatives), friends, advertisement in order. Other GYTS countries reported the similar sources of the smoking start and friend was prior smoking start factor to the other sources. The students who wanted to Quit smoking were 6.7% and the students who ever had tried to Quit smoking were 9.1%. The major reasons of Quitting smoking were for their health and for their financial burden. Approximately 60% learned about smoking and drug abuse in their regular school classes, 8.4% were in the special school activities, and 7.9% were in the class closing time sometimes in order. The students who learned in any regular class were smaller in the high school students than in the middle school students. The learning experiences in school of other GYTS countries were similar to that of Korea. In conclusion, students' smoking was affected not only by the preventive activities in school but also by the close people's behaviors and care in this study; therefore, the active partnership between school and family must be a strong strategy for youth's smoking prevention.

• Journal of the Korean Society of Food Culture
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• v.24 no.1
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• pp.1-9
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• 2009

The purpose of this research was to investigate consumers' perceptions of foods that are most compatible with traditional Korean liquors. The study participants were a total of 402 customers who visited traditional Korean bars. Thirty-eight percent of the participants drank alcohol once or twice a week, and overall, 79% drank with friends or co-workers. Forty-three percent spent 30,000-40,000 won on alcoholic drinks, and half of them frequently drank distilled Soju whereas 27% drank beer. Those who drank traditional Korean liquor chose to do so because they viewed it as good for their health and the beverage was tasty. Participants selected Yakju/Baekseju (47.5%), Bokbunjaju (21.1%), and Takju/Makgeoli (8.2%) as the most compatible Korean traditional liquors with Korean traditional foods. The most compatible foods with Yakju were identified as Haemulpajeon (11.8%), Dubukimchi (9.8%), and Bossam/Suyuk/Pyeonyuk (7.5%). Bokbunjaju was viewed as a good match with Jangeogui (8.1%), Hunjeori (6.5%), and Saengseonhoe (6.4%). The respondents perceived Deodeokgui (6.7%), Saengseonhoe (5.9%), and Dubukimchi (5.6%) as the most compatible foods with Yakju with mushrooms. Chengju was viewed as a good pairing with Eomuktang (9.2%), Altang/Maeuntang (7.2%), and Saengseonhoe (6.8%). The respondents thought Takju went well with Haemulpajeon (17.7%), Dubukimchi (14.2%), and Kimchijeon (11.7%). And finally, Altang/Maeuntang (11.8%), Samgyeopsalgui (8.7%), and Honghaptang/Jogaetang (8.1%) were mentioned as the most compatible foods with distilled Soju.

• Corrosion Science and Technology
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• v.14 no.2
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• pp.99-105
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• 2015

The structures of reinforced concrete have been extensively increased with rapid development of industrial society. Futhermore, these reinforced concretes are easy to expose to severe corrosive environments such as seawater, contaminated water, acid rain and seashore etc.. Thus, corrosion problem of steel bar embedded in concrete is very important in terms of safety and economical point of view. In this study, specimens having six different coating thickness (W/C:0.5) were prepared and immersed in flowing seawater for five years to evaluate the effect of coating thickness and immersion time on corrosion property. The polarization characteristics of these embedded steel bars were investigated using electrochemical methods such as corrosion potential, anodic polarization curve, and impedance. At the 20-day immersion, the corrosion potentials exhibited increasingly nobler values with coating thickness. However, after 5-yr. immersion their values were shifted in the negative direction, and the relationship between corrosion potential and coating thickness was not shown. Although 5-yr. immersion lowered corrosion potential, 5-yr. immersion did not increase corrosion rate. In addition, after 5-yr. immersion, the thinner cover thickness, corrosion current density was decreased with thinning coating thickness. It is due to the fact that ease incorporation of water, dissolved oxygen and chloride ion into a steel surface caused corrosion and hence, leaded to the formation of corrosion product. The corrosion product plays the role as a corrosion barrier and increases polarization resistance. The corrosion probability evaluated depending on corrosion potential may not be a good method for predicting corrosion probability. Hence, the parameters including cover thickness and passed aged years as well as corrosion potential is suggested to be considered for better assessment of corrosion probability of reinforced steel exposed to partially or fully in marine environment for long years.

• Journal of Wetlands Research
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• v.14 no.1
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• pp.139-146
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• 2012

Stream ecosystems carry out significant functions such as water purification, especially denitrification. However, rapid landuse change since industrialization has altered ecological functions of streams. In this study, we aimed to investigate denitrification rates and their determinant factors in streams with different landuse patterns, and how denitrification rates vary with microtopology within streams. Ten fifth streams of each landuse were selected, and each stream was divided into four microtopological sites within streams - riparian zone, subsoil, and both head and tail parts of sand bars. In situ denitrification rates and physicochemical properties of soil were examined. Denitrification rates of agricultural, urban, and forest streams were $289.62{\pm}70.69$, $157.01{\pm}37.06$, $31.38{\pm}18.65mg$ $N_2O-N\;m^{-2}\;d^{-1}$ respectively. There were no significant differences in denitrification rates depending on microtopology, but the rates in riparian zone were the highest, and the rates in the head parts of sandbars were lower than those of tail parts. The determinant factors for denitrification rates included water temperature, silt and clay contents of soil, inorganic nitrogen, and organic carbon, and these factors all showed positive correlations with denitrification rates. Through this study, we find that landuse pattern in watershed region affects denitrification rates that is one of considerable functions of streams. In addition, estimation of denitrification rates taking into account for microtopology would contribute to developing ecological management and restoration strategy of streams.

• Journal of the Korea Concrete Institute
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• v.28 no.5
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• pp.555-562
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• 2016

The objective of the present study is to evaluate the shear transfer capacity of transverse reinforcement at the concrete interfaces with smooth construction joint. The transverse reinforcing bars were classified into two groups: V-type for the arrangement perpendicular to the interface and X-type for inclined-crossing arrangement. The transverse reinforcement ratio at the interface varied from 0.0045 to 0.0135 for V-type and 0.0064 to 0.0045 for X-type. The mechanism analysis proposed for monolithic concrete interface, derived based on the upper-bound theorem of concrete plasticity, was modified to evaluate the shear friction capacity of concrete interfaces with smooth construction joint. Test results showed that the specimens with X-type reinforcement had lower amount of relative slippage at the interface and higher shear friction capacity than the companion specimens with V-type reinforcement. This observation was independent of the unit weight of concrete. The mean and standard deviation of the ratios between the experimental shear friction strength of smooth construction joints and predictions obtained from the proposed model are 1.07 and 0.14, respectively.

• Korean Journal of Applied Biomechanics
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• v.14 no.2
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• pp.27-40
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• 2004

The objective of this study is to identify the kinematic variables of giant swing backward to handstand as well as individual variations of each athlete performing this skill, which in turn will provide the basis for developing suitable training methods and for improving athlete's performance in actual games. For this end, 3 male athletes, members of the national team, who are in ${\Box}{\Box}H{\Box}{\Box}$ University, have been randomly chosen and their giant swing backward to handstand performance was recorded using two digital cameras and analyzed in 3 dimensional graphics. This study came to the following conclusion. 1. Proper time allocation for giant swing backward to handstand are: Phase 1 should provide enough time to attain energy for swing track of a grand round movement. The phase 3 is to throw the body up high in the air and stay in the air as long as possible to smoothen up the transition to the next stage and the phase 4 should be kept short with the moment arm coefficient of the body reduced. 2. As for appropriate changes of locations of body center, the phase 1 should be comprised of horizontal, perpendicular, compositional to make up a big rotational radius. Up to the Phase 3 the changes of displacements of vertical locations should be a good scale and athlete's body should go up high quickly to increase the perpendicular climbing power 3. When it comes to the speed changes of body center, the vertical and horizontal speed should be spurred by the reaction of the body in Phase 2 and Phase 3. In the Phase 4, fast vertical speed throws the body center up high to ensure enough time for in-the-air movement. 4. The changes of angles of body center are: in Phase 2, shoulder joint is stretching and coxa should be curved up to utilize the body reaction. In the Phase 4, shoulder joint and coxa should be stretched out to get the body center as high as possible in the air for stable landing. 5. The speeds of changes in joints angles are: in the Phase 2 should have the speed of angles of shoulder joints increase to get the body up in the air as quickly as possible. The Phase 3 should have the speed of angles in shoulder joint slow down, while putting the angles of a knee joint up to speed as quickly as possible to ensure enough time for in-the-air movement.

• Journal of Korea Water Resources Association
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• v.44 no.9
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• pp.765-776
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• 2011

Flood discharge capacity in a dam downstream reach has been decreased after dam construction because of the river cross section reduction impacted by farm lands, sand-bars and parking lots, etc. in river flood plains. Those obstacles being in the river inside areas have caused negative influences to the dam operation policy. Therefore, the dam downstream river improvement work associated with the dam operation improvement plan is under construction for removing reduction factors on the dam effective storage, assuring flood safety in the dam downstream river and incrementing dam operation benefits. But the project has issued some problems such as project feasibility, economic evaluation, cost allocation and benefit share, etc. Since a dam enterpriser has not committed such kind of project before, it is necessary to set up an objective analysis process and a quantitative financial valuation. This study examines the measurable economic benefits and the cost allocation of the project for the fairness between benefit owners (central government and water electricity enterprisers). As a result, the total economic benefit from 3 dams (Imha, Daechung and Youngdam Dam) accounts for 14.41 Billion Won/year. The financial valuation of K-water as a project enterpriser is approximately estimated at 40% of the total value and the government is 60%.

• Economic and Environmental Geology
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• v.32 no.5
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• pp.445-454
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• 1999

The Sanjeon Au-Ag deposit consists of three subparallel hydrothermal quartz-calcite veins which filled fault-related fractures (generally $N20^{\circ}$ to 35"W-trending and $70^{\circ}$ to $80^{\circ}$ SW-dipping) within quartz porphyry. The vein mineralization shows an apparent variation of mineral assemblages with paragenetic time: (1) early, white quartz + pyrite + arsenopyrite + brown sphalerite, (2) middle, white (vein) to clear quartz (vug) + base-metal sulfides + electrum + argentite, (3) late, calcite + pyrite + native silver. Mineralogic and fluid inclusion data indicate that gold-silver minerals were deposited at temperatures from 2l $0^{\circ}$ to $250^{\circ}$ with salinities of 4 to 5 wt. % equiv. NaCl and log fS2 values from -14.0 to -12.2 atm. The linear relationship between homogenization temperature and salinity data indicates that gold-silver deposition was a result of meteoric water mixing. Ore mineralization occurred at pressure conditions of about 70 bars, which corresponds to the mineralization depths of about 260 m to 700 m. There is a remarkable decrease of the calculated 1)180 values of water from 1.3 to -9.7%0 in hydrothermal fluid with increasing paragenetic time. This indicates a progressive increase of meteoric water influx in the hydrothermal system at the Sanjeon deposit. Oxygen-hydrogen, sulfur, and carbon isotope values of hydrothermal fluids indicate that the ore mineralization was formed largely from meteoric waters with the contribution of sulfur and carbon from a deep igneous source.

• Korean Journal of Food Science and Technology
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• v.8 no.2
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• pp.113-118
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• 1976

For this study, from July to December in 1975, the total of 160 samples of packaged ice creams(75 samples of carton, 50 samples of cone, and 35 samples of bar), manufactued by five different plants, were collected at markets in Seoul city area. And the chemical composition and microbial quality of those were analyzed and compared with each other samples. The results obtained are as follows: 1. The average milk fat contents of ice cream samples were 6.28% in carton, 6.42% in cone and 4.94% in bar. 2. The average total solid contents of ice cream samples were 33.45% in carton, 34.22% in cone and 29.46% in bar. 3. The average total protein contents of ice cream samples were 3.45% in carton, 3.16% in cone and 2.42% in bar. 4. The average milk solids-not-fat contents of ice cream samples were 10.46% in carton, 8.52% in cone and 7.72% in bar. 5. The average milk lactose contents of ice cream samples were 6.42% in carton, 5.57% in cone and 4.94% in bar. 6. The average crude ash contents of ice cream samples were 0.86% in carton, 0.78% in cone and 0.67% in bar. 7. The average Reichert-Meissl values of ice cream samples were 28.82 in carton, 27.85 in cone and 25.97 in bar. 8. In the both experiments of standard plate count and coliform count, the samples of ice cream in cone and carton showed lesser numbers than those in the form of bars. Of a total 160 samples examined, 6 samples gave standard plate counts of over 40,000/ml and 14 samples gave coliform counts of over 10/ml.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.6
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• pp.455-463
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• 1998

RCCA(rod cluster control assembly) End-Tip suffers from neutron irradiation and constant vibration due to high-speed internal flow of primary coolant during plant operation. Such operating conditions cause the RCCA end-tip crackings around tile circumferential weldment of the end-tip, and in some cases, the defective end-tips were completly broken loose. However, no reliable inspection techniques for end-tip crackings were developed in the past, although some techniques exist for inspecting RCCA control rod wears. Therefore, NDE group at KEPRI has developed an ECT technique for the detection and the sizing of the end-tip crackings. The technique uses a specially designed surface-riding probe that can detect size of circumferential crackings with an accuracy of ${\pm}5.31%$ RMS error. This paper describes the ECT instrumentation including the ECT probes, calibration bars, as well as technical approaches.