• Journal of the Korean Society of School Health
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• v.22 no.1
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• pp.49-59
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• 2009

Purpose: The aim of this study was to identify the factors related with the intention of smoking abstinence among elementary students in a metropolitan city in Korea. Methods: All the elementary schools in the city were stratified by region, and then schools as a primary sampling units (PSU) were selected by probability proportional to size (PPS) sampling. One class per grade was sampled randomly from 5th and 6th grade in the sampled schools from October to December in 2004. The students completed a standardized self-administered questionnaire anonymously. A total number of 1,712 respondents who did not smoke was included in the final analysis. The dependent variable was an intention of smoking in the future, and it was dichotomized into 'absolutely confident in smoking abstinence' and 'others'. The risk of non-absolute confidence in smoking abstinence was calculated with simple and multiple logistic regression, which were conducted with STATA 9.0 by a design-based analysis considering strata variable, PSU, and sampling weight. Results: In the final model of multiple logistic regression analysis, those who were more likely to have non-absolute confidence in smoking abstinence were male students (OR=2.66, p<0.001); barely attending religious services (OR=3.32, p=0.002) or having no religion (OR=1.95, p=0.027); exposure to environmental tobacco smoke outside home 1${\sim}$2 days per week (OR=1.60, p=0.013); having friends who smoked (OR=1.93, p=0.011); non-absolute confidence in refusing to smoke (OR=5.35, p<0.001); having relatively less negative attitude (OR=2.88, p<0.001), positive attitude (OR=2.35, p<0.001), and indifference (OR=4.05, p=0.034) toward peer smoking; not good relationship with mother (OR=1.52, p=0.016). Conclusion: The factors related with non-absolute confidence in smoking abstinence were coincided with those of smoking among children. The results of this study suggest the smoking prevention education should be applied to the children more actively, especially who are not confident in smoking abstinence in the future.

• Nuclear Engineering and Technology
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• v.43 no.6
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• pp.583-592
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• 2011

The radiological characteristics for waste classification were assessed for neutron-activated decommissioning wastes from a CANDU reactor. The MCNP/ORIGEN2 code system was used for the source term analysis. The neutron flux and activation cross-section library for each structural component generated by MCNP simulation were used in the radionuclide buildup calculation in ORIGEN2. The specific activities of the relevant radionuclides in the activated metal waste were compared with the specified limits of the specific activities listed in the Korean standard and 10 CFR 61. The time-average full-core model of Wolsong Unit 1 was used as the neutron source for activation of in-core and ex-core structural components. The approximated levels of the neutron flux and cross-section, irradiated fuel composition, and a geometry simplification revealing good reliability in a previous study were used in the source term calculation as well. The results revealed the radioactivity, decay heat, hazard index, mass, and solid volume for the activated decommissioning waste to be $1.04{\times}10^{16}$ Bq, $2.09{\times}10^3$ W, $5.31{\times}10^{14}\;m^3$-water, $4.69{\times}10^5$ kg, and $7.38{\times}10^1\;m^3$, respectively. According to both Korean and US standards, the activated waste of the pressure tubes, calandria tubes, reactivity devices, and reactivity device supporters was greater than Class C, which should be disposed of in a deep geological disposal repository, whereas the side structural components were classified as low- and intermediate-level waste, which can be disposed of in a land disposal repository. Finally, this study confirmed that, regardless of the cooling time of the waste, 15% of the decommissioning waste cannot be disposed of in a land disposal repository. It is expected that the source terms and waste classification evaluated through this study can be widely used to establish a decommissioning/disposal strategy and fuel cycle analysis for CANDU reactors.

• Journal of the Korean Vacuum Society
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• v.9 no.3
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• pp.237-241
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• 2000

The structural, electrical and etching characteristics of Al alloy thin film with low impurity concentrations AlNd deposited by using do magnetron sputtering deposition are investigated for the applications as gate bus line in the TFt-LCD panel. And ITO thin film was deposited on AlNd, then the contact resistance was measured by Kelvin resistor. The deposited thin films show the decrease of resistivity and the increase of grain size after the RTA at $300^{\circ}C$ for 20 min. Moreover, the resistivity of AlNd does not show appreciable grain size dependence after RTA. It is concluded that the decrease of resistivity after RTA is due to the increase of grain size. The annealed AlNd is found to be hillock free. The etching profiles of AlNd was good and the minimun contact resistance was about $110\;{\mu\Omega}cm$. Calculation results reveal that the AlNd (2wt.%) thin film can be applicable to 25" SXGA class TFT-LCD panels.

• Journal of the korean society of oceanography
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• v.32 no.4
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• pp.163-170
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• 1997

Some CMP gathers acquired from shallow marine seismic reflection survey in offshore Korea do not show the hyperbolic trend of moveout. It originated from so-called swell effect of source and streamer, which are towed under rough sea surface during the data acquisition. The observed time deviations of NMO-corrected traces can be entirely ascribed to the swell effect. To correct these time deviations, a residual statics is introduced using Genetic Algorithms (GA) into the swell correction. A new class of global optimization methods known as GA has recently been developed in the field of Artificial Intelligence and has a resemblance with the genetic evolution of biological systems. The basic idea in using GA as an optimization method is to represent a population of possible solutions or models in a chromosome-type encoding and manipulate these encoded models through simulated reproduction, crossover and mutation. GA parameters used in this paper are as follows: population size Q=40, probability of multiple-point crossover P$_c$=0.6, linear relationship of mutation probability P$_m$ from 0.002 to 0.004, and gray code representation are adopted. The number of the model participating in tournament selection (nt) is 3, and the number of expected copies desired for the best population member in the scaling of fitness is 1.5. With above parameters, an optimization run was iterated for 101 generations. The combination of above parameters are found to be optimal for the convergence of the algorithm. The resulting reflection events in every NMO-corrected CMP gather show good alignment and enhanced quality stack section.

• Journal of Yeungnam Medical Science
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• v.12 no.2
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• pp.393-399
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• 1995

Mandibular retrusion showing the facial problem with a marked maxillarry incisors protrusion and chin deficiency, resulting in a highly convex profile is uncommon in Korea.. The large incisor overjet and deep-bite create functional limitations and unpleasing esthetic result. The majority of theses cases are susceptible to correction by orthodontic therapeutic methods. But severe Class II retrognathic cases in which orthodontic treatment alone has not been capable of achieving good results. Orthognathic surgery offers several approaches. In this case, mandibular advancement by bilateral sagittal split ramus osteotomy and augmentation genioplasty has a special surgical problems. The suprahyoid muscle gorup are lengthened if the body of the mandible is surgically repositioned anteriorly. Instability of results and relapse return to original position shoud predicted during post-surgical muscular readjustment.. To maintain maximum correction with this technique, it is suggested that the mandibular body be well rotated forward at time of surgical intervention and overcorrected anteriory as much as possible. So, the authors report the case with review of concerned literature.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.73-73
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• 2009

In this sutdy, a new class ACA(Anisotropic Conductive Adhesive) with low-melting-point alloy(LMPA) and self-organized interconnection method were developed. This developed self-organized interconnection method are achieved by the flow, melting, coalescence and wetting characteristics of the LMPA fillers in ACA. In order to observe self-interconnection characteristic, the QFP($14{\times}14{\times}2.7mm$ size and 1mm lead pitch) was used. Thermal characteristic of the ACA and temperature-dependant viscosity characteristics of the polymer were observed by differential scanning calorimetry(DSC) and torsional parallel rheometer, respectively. A electrical and mechanical characteristics of QFP bonding were measured using multimeter and pull tester, respectively. Wetting and coalescence characteristics of LMPA filler particles and morphology of conduction path were observed by microfocus X-ray inspection systems and cross-sectional optical microscope. As a result, the developed self-organized interconnection method has a good electrical characteristic($2.41m{\Omega}$) and bonding strength(17.19N) by metallurgical interconnection of molten solder particles in ACA.

• International Journal of Naval Architecture and Ocean Engineering
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• v.3 no.3
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• pp.208-215
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• 2011

A full-scale field trial in ice-covered sea is one of the most important tasks in the design of icebreaking ships. The first Korean icebreaking research vessel 'ARAON', after her delivery in late 2009, had a sea ice field trial in the Arctic Sea during July-August, 2010. This paper describes the test procedures and data analysis on the icebreaking performance of the IBRV ARAON. The data gathered from the icebreaking performance test in the Chukchi Sea and the Beaufort Sea during the Arctic voyage of ARAON includes the speed and engine power of the ship as well as sea ice thickness and strength data. The air temperature, wind speed and heading of the ship were also measured during each sea ice trial. The ARAON was designed to break 1 m thick level ice with a flexural strength of 630kPa at a continuous speed of 3knots. She is registered as a KR POLAR 10 class ship. The principal dimensions of ARAON are 110 m, 19 m and 6.8 m in length, breadth and draft respectively. She is equipped with four 3,500kW diesel-electric main engines and two Azipod type propulsion motors. Four sea ice trials were carried out to understand the relationship between the engine power and the ship speed, given the Arctic ice condition. The analysis shows that the ARAON was able to operate at 1.5knots in a 2.5m thick medium ice floe condition with the engine power of 5MW, and the speed reached 3.1 knots at the same ice floe condition when the power increased to 6.6MW. She showed a good performance of speed in medium ice floe compared to the speed performance in level ice. More detailed analysis is summarized in this paper.

• Journal of the Korea Society of Computer and Information
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• v.19 no.11
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• pp.73-79
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• 2014

In the period of rising the importance of software education, unplugged activities has drawn attention as one of the various educational approaches. It has a good reputation in educational effectiveness and usefulness in an aspect of learning the principle of computer science. This paper proposes the tool that allows unplugged learning contents to be used in the web based on HTML5 in order to enhance its merits and accessibilities. The proposed tool is easy to access because it is operated on the level of web browser with no plug in or extra application programs. In addition, as a learner focused contents aiming at interaction on the web environment, it is well organized for school class room.

• Hwankyungkyoyuk
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• v.13 no.1
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• pp.75-86
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• 2000

The purpose of this study is to analyze the content of environmental inquiry activities and values of elementary school students written in their reports of the Energy Environment Inquiry Activity Contest which is a unit contest of the Youth Science Festival held annually in Korea and get some ideas for the valuable way of Korean environmental education. 10 teams' reports were gathered and the locality, class study area, inquiry theme, inquiry method and values were analyzed and introduced as case studies to get some insights to teach elementary school students environmental values through inquiry activities of science subject approach. Each teams set various inquiry themes in the content domain of energy resources and earth environment conservation focusing on each team's geographical characteristics and occurring environmental problems in their local areas. There were 16 sentences representing technocentrism and 12 sentences representing ecocentrism. 5 of 10 teams showed both of technocentrism and ecocentrism in their reports. But their was only scientific knowledge without any environmental values in one team's report. Inquiry activity is a good teaching-learning method to develop environmental literacy. There should be environmental values involved as far as it is the environmental inquiry activities using environmental subject matter. The result of this study proposes that environmental educators should actively intervene for inquirers to set a stage in the whole process to search for an alternative to solve environmental problems involved in their project activities. The reason is because the environmental education in the elementary school is established to operate by the infusion way into various subjects already existed in the Korean curriculum.

• Journal of Neurogastroenterology and Motility
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• v.24 no.4
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• pp.584-592
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• 2018

Background/Aims There is uncertainty about how to measure outcomes reported by patients in gastroesophageal reflux disease (GERD). This study was conducted to develop an instrument and to determine of the definition of respondent for a patient reported outcomes to assess the efficacy of a treatment used for GERD treatment. Methods A structural process has developed a self-evaluation questionnaire for GERD (SEQ-GERD); health-related quality of life questionnaire for GERD (GERD-QOL) was translated through cross-cultural validation. Two-week reproducibility was evaluated and construct validity was assessed by correlating the SEQ-GERD with the Patient Assessment of Gastrointestinal Disorders (PAGI-SYM), the reflux disease questionnaire (RDQ), and GERD-QOL. Changes in SEQ-GERD scores were compared to assess the discriminative validity following 4 weeks of proton pump inhibitor administration. Results A total of 83 Korean patients were included (mean age $46{\pm}14$ years, females 61.4%). The internal consistency of the 19-item SEQ-GERD was good (alpha = 0.60-0.94) and the test-retest reliability was high (intra-class correlation coefficient = 0.67-0.95). The SEQ-GERD highly correlated with the GERD domain of the PAGI-SYM (correlation coefficient r = 0.894, P < 0.001), the RDQ-GERD (r = 0.877, P < 0.001), and GERD-QOL (r = -0.536, P < 0.05). SEQ-GERD scores significantly varied according to the overall treatment effectiveness scale of drug responsiveness and significantly decreased after drug treatment (mean differences according to the overall treatment effectiveness scale, P = 0.020). Conclusion This study supports that SEQ-GERD is reliable and valid, and can be used to evaluate the treatment response in patients with GERD.