• Journal of the Korea Concrete Institute
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• v.17 no.2 s.86
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• pp.179-189
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• 2005

Corrosion of steel due to chloride attack is a major concern in reinforced concrete structures which are located in the marine environments. In this case, Fick's 2nd law has been used for the prediction of chloride diffusion related with service life of concrete structures. However, those studies were confined mostly to the single deterioration due to chloride only, although actual environment is rather of combined type. The purpose of the present study is, therefore, to explore the influences of carbonation to chloride attack in concrete structures and to investigate the validity of Fick's law to chloride attack combined carbonation. The test results indicate that the chloride ion profiles from Fick's law using the diffusion coefficient of immersion tests is not reflected the effect of separation of chloride ions in carbonation region but valid in sound region in case of combined action. On the other hand, the chloride ion profiles from Fick's law using the diffusion coefficient of Tang and Nilsson's method coincide with test results under dry-wet condition but not under combined condition. The results of present study may Imply that the new method for the measurement of diffusion coefficient is required to predict the chloride ion profiles in case of combined action at early.

• 대한공업교육학회지
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• v.39 no.1
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• pp.247-261
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• 2014

Education about invention in elementary schools has thus far be conducted mostly through special activities and talented activities rather than through normal curricula. However, with the implementation of the 2007 amended curricula, invention education was reflected as a normal subject unit in the practical subject (technology and home economics) curricula, thereby laying groundwork for invention education being able to be provided through normal subject classes. Thus, at the time when invention education has been reflected as a normal subject unit, it is meaningful to research the effects of elementary school students' experience in invention education on their invention attitudes. This study sought to research the effects of elementary school students' experience or non-experience in invention education on their invention attitudes, targeting those in regional talent private schools who did not take invention talent classes, those who received invention education, and those who did not receive invention education at all. The conclusion of this study is outlined as follows. First, students' experience in invention education proved to be positive in boosting their invention attitude, and continued invention education experience like with students in regional talent invention schools significantly boosted their invention attitudes. Second, considering that students' actual experience in invention education had positive effects on their invention attitudes, the reflection of invention education in the amended curricula was found to be very desirable in improving elementary students' attitudes about invention. Third, according to gender, male students' invention attitude level was found to be higher than that of female students, suggesting that male students more worked on computers, electronic (smart) devices and machines in daily life, leading them to further develop invention attitudes.

• Journal of the Korean Society of Safety
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• v.31 no.3
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• pp.143-155
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• 2016

Recently, a massive loss of life and property is occurring in Korea due to traffic accidents, with the rapid increase in cars. For improvement of traffic safety, the Korea Transportation Safety Authority intensively analyzes accident data in local governments with low traffic safety index, performs a field investigation to extract problems and offers local governments improvements for problems, by conducting the 'Special Survey of Actual Conditions of Traffic Safety' each year, starting 2008. But local governments cannot strongly push forward the improvement projects due to the limited budget and the uncertainty of the improvement plan effects. Therefore, this study suggested a model which applied the Utility concept to the AHP theory, in order to efficiently decide a priority of the improvement plans in accident black spots in consideration of the limited budget of local governments. The number of accidents in each spot for improvement and accident severity, traffic volume, pedestrian volume, the improvement project cost and the accident reduction effect were chosen as evaluation factors for deciding a priority, and data about the improvement plan costs and the accident reduction effects, traffic accidents and traffic volume in the spots to undergo the special research on the real condition of traffic accident in the past were collected from the existing studies. Then, regression analysis was carried out and the Utility Curve of each evaluation factor was computed. Based on the AHP analysis findings, this study devised a priority decision method which calculated the weight and the utility function of each evaluation factor and compared the total utility values. The AHP analysis findings showed that among the evaluation factors, accident severity had the biggest importance and it was followed by the improvement plan cost, the number of accidents, the improvement effect, traffic volume and pedestrian volume. The calculated utility function shows a rise in utility, as the variables of the 5 evaluation factors; the number of accidents, accident severity, the improvement plan effect, traffic volume and pedestrian volume increase and a fall in utility, as the variables of the improvement plan cost increase, since the improvement plan cost is included in the budget spent by a local government.

• Korean Journal of Agricultural and Forest Meteorology
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• v.19 no.4
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• pp.270-279
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• 2017

Regional assessment of crop productivity using a gridded simulation approach could aid policy making and crop management. Still, little effort has been made to develop the systems that allows gridded simulations of crop growth using ORYZA 2000 model, which has been used for predicting rice yield in Korea. The objectives of this study were to develop a series of data processing modules for creating input data files, running the crop model, and aggregating output files in a region of interest using gridded data files. These modules were implemented using C++ and R to make the best use of the features provided by these programming languages. In a case study, 13000 input files in a plain text format were prepared using daily gridded weather data that had spatial resolution of 1km and 12.5 km for the period of 2001-2010. Using the text files as inputs to ORYZA2000 model, crop yield simulations were performed for each grid cell using a scenario of crop management practices. After output files were created for grid cells that represent a paddy rice field in South Korea, each output file was aggregated into an output file in the netCDF format. It was found that the spatial pattern of crop yield was relatively similar to actual distribution of yields in Korea, although there were biases of crop yield depending on regions. It seemed that those differences resulted from uncertainties incurred in input data, e.g., transplanting date, cultivar in an area, as well as weather data. Our results indicated that a set of tools developed in this study would be useful for gridded simulation of different crop models. In the further study, it would be worthwhile to take into account compatibility to a modeling interface library for integrated simulation of an agricultural ecosystem.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.9
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• pp.5931-5941
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• 2015

It should be given the opportunity to acquire information about the health of infants for a new type of way of life with the passage of time, of which the internet is a lot of people are required to use the media in the modern world. So, we want to find out the status of kindergarten teachers' internet utilizing and how to utilize the internet health information on field. The purpose of this study is to explore the direction of improvement. We produce this research based on a precedent study about perception and actual condition of health information utilizing. The objects of this study are 180 kindergarten teachers working in Dae-jeon and most of them have experience of searching health information through internet. The collected data calculated frequency and percentage with SPSS 18.0 program. As a result, first, kindergarten teachers think the information of infants' health is relatively important, still they obtain it from the Internet. But they feel a difficulty in finding the proper information because it takes so much time. Second, they utilize the Internet whenever necessary to find health information and they could find it. However, health information obtained from the Internet, have not been unexpectedly useful. Therefore, training about the content of infant's health and utilizing method of internet health information is needed.

• Journal of Navigation and Port Research
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• v.35 no.6
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• pp.477-482
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• 2011

Solar flares have the 11-year cycle and release a large energy which may produce coronal mass ejections (CME). The NOAA (National Oceanic and Atmospheric Administration) predicted that the sun spot activity will be maximized in 2013-2014. A strong solar flare can cause the disturbance of global positioning system including various communication of TV, radio broadcasting. The actual solar storm in 1989 caused power outages in Canada during 9 hours and about 600 million people had experienced a blackout. Such a solar storm can shorten the GPS satellite's life span about 5 to 10 years which can resulted in economic loss considering the amount of multi-billion won. This paper analyzed the influence of recent X-class solar storm occurred on 15th of February about 10:45 this year that was reached Korea (Bohyun observatory) on 18th of February about 10:30 (01:30 - UTC), and compared with the data before and after a week. The proton data of 18th of February considered that the solar storm reached on earth showed a fluctuation compared to the data before and after a week. The positioning results at Daejeon and Seoul of Korea also showed higher positioning error compared to the data before and after a week results.

• The KIPS Transactions:PartC
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• v.8C no.6
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• pp.831-838
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• 2001

Mobile information service aims to provide some degree of effective information for real life activities of mobile users. Due to the user mobility and actual realism, it becomes very important technical issue to support an adaptive information service methodology to current situations of the terminal and/or user. This paper deals with a prefetching scheme for location-aware, out of the various context-aware which can be considered in mobile information service. It makes use of the velocity-based mobility model to shape the terminal and/or user's mobility behavior. Based on the moving speed and direction, the prefetching zone is proposed to define the number of prefetched information, so as to limit effectively the prefetched information whilst to preserve the location-aware adaptability. Using a simulator, the proposed scheme has been evaluated in the effectiveness point of view. The idea in this paper is expected to be able to extended to the other mobile service contexts, such as service time, I/O types of mobile terminals, network bandwidth.

• The Journal of Pediatrics of Korean Medicine
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• v.21 no.3
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• pp.125-143
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• 2007

Objective The purpose of this study was to investigate health and life style of pediatric outpatients who visited the oriental hospital. Methods The study was composed of 363 students from elementary school, middle school and high school who visited the pediatrics department in $\bigcirc\;\bigcirc$ university oriental medicine hospital between 2005 and 2006. Results 1. The group wasconsisted with 56% of male and 44% of female student and for the age distribution, 7.4% were elementary school students, 55.6% were middle school students, and 36.9% were high school students. 2. Usually the eldest child tends to visit hosipital more than the younger ones. 3. More than a half of those students' parent had University education or beyond that. 4. There were more students who had below the level of the height-weight curve than in the higher level. 5. The average study hours of the students were 3.67 hours. An average sleep hours was 6.18 hours. An average exercise hour was 1.16 hours and an average time for watching TV was 1.71 hours. 6. Many students had hard time to concentrate on the studying for a long time. 7. For the question about the reason why they got the poor grade, they answered because of the lower concentration, and they didn't put much effort on the studying. The most they concern about was their grade. 8. Most of the students who visited the clinic said they did not feel refreshed when they woke up in the morning, and, many of them said that they don't feel okay. 9. More than an half of the students wear glasses. 10. More than an half of the students answered that they often catch a cold when the weather changes a lot. 11. A lot of them had some digestive problems. 12. As they getting older, they said they often feel back pain and shoulder pain. 13. Many students felt irritated and got mad easily. Many of them felt bored about their study and stressed out because of their tests and the university entrance exams. 14. Most of the female students answered that they have irregular period or cramps. 15. 21% of them usually skip breakfast. 16. Many students enjoyed snacks. Most of them enjoyed snacks after school. As they go into higher grade, they would like to eat at night especially cookies, bread and fruits. Conclusions Further studies with larger sample size of students will be neededfor accurate results, and it would be better if we can compare the conditions of the students before treatments and after those.

• Journal of the Korean Society for Library and Information Science
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• v.49 no.3
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• pp.209-231
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• 2015

The main purpose of this study is to develop and apply a means of connecting reading movement and Newspaper In Education (NIE) activities utilizing the voluntary participation and cooperation of local school districts and autonomous government entities. This is necessary to revitalize or systematize the environmental social life of reading newspapers and NIE activity. Literary or inquiry research will be initiated in this study in order to quantify the current or actual conditions of this connection, delineating the basic objectives of this study, and determining the developmental directions for continuing this study as related to the connection of reading movement and NIE activity. Anticipated study activities or major tasks are as follows. First, develop a variety of intended programs and learning materials necessary for each. Secondly, develop and establish corresponding online data and educational programs. Thirdly, a "cooperation" system must be established and training programs implemented reinforcing these ideas. And, lastly (and to gain wider acceptance), starting a public relations campaign to show or illustrate the benefits of this study and these intended research activities. In conclusion, if a connection between reading movement and NIE activity are fully established and periodically adjusted by means of continuing discussions on the merits or concerns based on the study findings, the full potential of the reading movement connection with NIE activity will be realized and achieved to its truest meaning and/or highest order.

• Journal of Korean Society of Forest Science
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• v.78 no.2
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• pp.228-241
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• 1989

The objectives of this study are to identify flood disasters resulted from heavy rainstorm including earth and stone-debris avalanches and also to develope the scientific data to be needed for establishing the landslide-related disaster prevention countermeasures. For this study, 5 Gun (district) regions including Booyeo, Seochun, Gongju, Boryung, and Chungyang in Chungchongnam-do of the central part of Korea, in which severe landslide damages have been triggered during 3 days from July 21 to July 23, 1987, were investigated. Mostly, landslides having death of human lives triggered from 6 a.m, to 8 a,m. on July 22, and the principal factor was proved to be the continuous heavy rain ; the continuous rainfall of internal region for 3 days measured about 300-673 mm. The structural measures for slope failure prevention countermeasures at the hollow part of upper hillslope should be required. Natural drainage network on slopes should not be disturbed in case of land use alteration, such as a chestnut planting work on hillslopes behind the houses particularly. There are so many problems in recognition of landslide disaster prevention countermeasures including evacuation exercises. More actual education of countermeasures for control of flood and landslide should be put to practice through "civil defense education" and "inhabitants' meeting." In this context, existing Erosion Control Stations of 13 regions established in each Province should not be reduced. The designation criterion and surveying processes of "Landslide Prone Site" published by Forest Administration should also be improved scientifically.