• Journal of The Korean Association For Science Education
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• v.34 no.8
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• pp.703-718
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• 2014

This study sought to investigate learning progressions for astronomical systems which synthesized the motion and structure of Earth, Earth-Moon system, solar system, and the universe. For this purpose we developed ordered multiple-choice items, applied them to elementary and middle school students, and provided validity evidence based on the consequence of assessment for interpretation of learning progressions. The study was conducted according to construct modeling approach. The results showed that the OMCs were appropriate for investigating learning progressions on astronomical systems, i.e., based on item fit analysis, students' responses to items were consistent with the measurement of Rasch model. Wright map analysis also represented that the assessment items were very effective in examining students' hypothetical pathways of development of understanding astronomical systems. At the lower anchor of the learning progression, while students perceived the change of location and direction of celestial bodies with only two-dimensional earth-based view, they failed to connect the locations of celestial bodies with Earth-Moon system model, and they could recognized simple patterns of planets in the solar system and milky way. At the intermediate levels, students interpreted celestial motion using the model of Earth rotation and revolution, Earth-Moon system, and solar system with space-based view, and they could also relate the elements of astronomical structures with the models. At the upper anchor, students showed the perspective change between space-based view and earth-based view, and applied it to celestial motion of astronomical systems, and they understood the correlation among sub-elements of astronomical systems and applied it to the system model.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.3
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• pp.199-207
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• 2013

Purpose: The importance of occlusal contacts of the natural dentition for durability of teeth, mandibular stabilization, and restorative dentistry is well known. The purpose of this study is to analyze the occlusal contact and guidance pattern of Koreans by evaluating the static occlusion on maximal intercuspal position and measuring dynamic occlusion during straight protrusion. Materials and methods: The occlusal contacts at maximal interincisal position and the occlusal guidance pattern during straight protrusion of 29 subjects were recorded with shimstock foil (Whaledent, Langenau, Germany), T-Scan III (Tekscan Inc., Boston, MA, USA), polyvinylsiloxane registration material (Genie Bite, Sultan Healthcare, Hackensack, NJ, USA) and compared. Occlusal registration procedures were repeated 3 times. The position was fixed to an upright position and the head position was fixed with the Frankfurt horizontal plane paralleling the horizontal plane. Fisher's Exact Test (R-General Public License, ver. 2.14.1) and Pearson's Test were used to assess the significance level of the differences between the experimental groups (${\alpha}=.05$). Results: When using shimstock foil, T-Scan III system, and polyvinylsiloxane registration material, most of the patients showed contact on anterior, premolar, and molar teeth during maximal intercuspal position. Approximately 51% of maximal intercuspal position showed anterior contact using shimstock foil. When examining the protrusive movement using shimstock foil and T-Scan III system, guidance pattern with the central incisor was the most common. Conclusion: During maximal intercuspal position, there were cases in which not all of the teeth showed occlusal contact. During mandibular protrusive movements, one or more maxillary central incisors frequently joined in straight protrusion and the posterior teeth were disoccluded. Therefore, the anterior teeth protect the posterior teeth, and vice versa. Thus, mutually protected occlusion should be applied when reconstructing occlusion.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1560-1566
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• 2013

This study was conducted to find out the effects of aqueous extract from the leaves of Artemisia capillaris (AA) on the reduction of hepatotoxicity induced by ethanol in rats. In this experiment, Sprague Dawley rats were used in the experimental groups, which were divided into 5 groups; normal group, ethanol+UDCA (ursodeoxycholic acid)-treated group (positive control), ethanol-treated group (control), ethanol+Artemisia capillaris aqueous extract-treated group (200 mg/kg of BW) and ethanol+Artemisia capillaris aqueous extract-treated group (400 mg/kg of BW). AST (aspartate aminotransferase), ALT (alanine aminotransferase), GGT (gamma(${\gamma}$)-glutamyl transferase) and LDH (lactate dehydrogenase) activities of the ethanol+Artemisia capillaris aqueous extract-treated group (400 mg/kg of BW) were significantly decreased compared to that of the ethanol-treated group (P<0.05). The triglyceride level of the ethanol-treated group was significantly increased and the HDL-cholesterol level was significantly decreased compared to the normal group (P<0.05). On the other hand, the triglyceride level was significantly decreased (P<0.05) and the HDL-cholesterol level was significantly increased (P<0.05) in the ethanol+Artemisia capillaris aqueous extract-treated groups. Superoxide dismutase (SOD) activity was enhanced significantly (P<0.05) in the ethanol+Artemisia capillaris aqueous extract-treated groups. Also, malondialdehyde contents were decreased in this group (P<0.05). Histologically, in the control group, there was a mild degenerative change around central venule. The AA treated group showed well preserved lobular architectures with no evidence of steatosis or liver damage in aqueous extract from the leaves of Artemisia capillaris treated group (H&E, ${\times}20$). As the results of this study, it is thought that Artemisia capillaris aqueous extract may have effects on the improvement of hepatic damage by ethanol.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.11 no.5
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• pp.1-13
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• 2016

This study aims to observe the impacts of entrepreneurship and market orientation of Seoul's business incubator (BI) CEO's on business performance, as well as investigate the moderating effects of BI supporting services. The main objectives of this study are as follows: first, to observe how the entrepreneurship of CEO's affects business performance; second, to observe how CEO's market orientation as a cultural factor attributes to business performance; third, to verify whether the utilization level of BI supporting services shows moderating effects between entrepreneurship and business performance, and finally to verify whether the utilization level of BI supporting services shows moderating effects between market orientation and business performance. Business incubators in Seoul registered with the Business Incubator Association were surveyed both online and offline to receive 127 responses out of 320 circulations. By filtering out insincere reponses, 117 were used for statistical analysis. Our results assert that the utilization level of physical BI supporting services does indeed strengthen the relation between initiative and financial performance. Also, it is interesting to note that the utilization level of physical BI supporting services supports the relation between risk sensitivity and financial performance. While risk sensitivity on its own shows no positive effect on business performance, a suitable utilization level of BI supporting services is likely to strengthen the connection. In addition, the utilization level of both physical and non-physical supporting services shows a moderating effect between initiative and non-financial performance. Based on the results above, risk-taking business incubator CEOs with initiative are likely to yield better financial performance in terms of increasing sales, if provided with various physical supporting services such as sufficient educational facilities including communal spaces and conference rooms.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3A
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• pp.235-249
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• 2011

A new form of I-type PSC bridge girder, which has hole in the web, is proposed in this paper. Three different concepts were combined and implemented in the design. First of all, a girder was precast at a manufacturing plant as divided pieces and assembled at the construction site using post-tensioning method, and the construction period at the site will be reduced dramatically. In this way, the quality of concrete can be assured at the manufacturing factory and concrete curing can be well controlled, and the spliced girder segments can be moved to the construction site without a transportation problem. Secondly, a numerous number of holes was made in the web of the girder. This reduces the self-weight of the girder. But more important thing related to the holes is that about half of the total anchorages can be moved from the girder ends into individual holes. The magnitude of negative moment developed at girder ends will be reduced. Also, since the longitudinal compressive stresses are reduced at ends, thick end diaphragm is not necessary. Thirdly, Prestressing force was introduced into the member through multiple stages. This concept of multi-stage prestressing method overcomes the prestressing force limit restrained by the allowable stresses at each loading stage, and maximizes the magnitude of applicable prestressing force. It makes the girder longer and shallower. Two 50 meter long full scale girders were fabricated and tested. One of them was non-spliced, or monolithic girder, made as one piece from the beginning, and the other one was assembled using post-tensioning method from five pieces of segments. It was found from the result that monolithic and spliced girder show similar load-deflection relationships and crack patterns. Girders satisfied specific girder design specification in flexural strength, deflection, and live load deflection control limit. Both spliced and monolithic holed web post-tensioned girders can be used to achieve span lengths of more than 50m with the girder height of 2 m.

• Information Systems Review
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• v.18 no.1
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• pp.57-78
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• 2016

Hacking has raised many critical issues in the modern world, particularly because the size and cost of the damages caused by this disruptive activity have steadily increased. Accordingly, many significant studies have been conducted by behavioral scientists to understand hackers and their practices. Nonetheless, only qualitative methods, such as interviews, meta-studies, and media studies, have been employed in such studies because of hacker sampling limitations. Existing studies have determined that intrinsic motivation was the dominant factor influencing hackers, and that their techniques were mainly acquired from online hacking communities. However, such results have yet to be causally proven. This study attempted to identify the causal factors influencing the motivational and environmental factors encouraging hackers to learn hacking skills. To this end, hacker community members using the theory of planned behavior were observed to identify the causal factors of their learning of hacking skills. We selected a group of students who were developing their hacking skills. The survey was conducted over a two-week period in May 2015 with a total of 227 students as respondents. After list-wise deletion, 215 of the responses were deemed usable (94.7 percent). In summary, the hackers were aware that hacking skills are considered socially unethical, and their attitudes toward the learning of hacking skills were affected by both intrinsic and extrinsic motivations. In addition, the characteristics of the online hacking community affected their perceived behavioral control. This study introduced new concepts in the process of conducting a causal relationship analysis on a hacker sample. Moreover, this research expanded the discussion on the causal direction of subjective norms in unethical research, and empirically confirmed that both intrinsic and extrinsic motivations affect the learning of hacking skills. This study also made a practical contribution by raising the educational and policy response issues for ethical hackers and demonstrating the necessity to intensify the punishment for hacking.

• Progress in Medical Physics
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• v.24 no.2
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• pp.127-132
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• 2013

The position of the internal organs can change continually and periodically inside the body due to the respiration. To reduce the respiration induced uncertainty of dose localization, one can use a respiratory gated radiotherapy where a radiation beam is exposed during the specific time of period. The main disadvantage of this method is that it usually requests a long treatment time, the massive effort during the treatment and the limitation of the patient selection. In this sense, the combination of the real-time position management (RPM) system and the volumetric intensity modulated radiotherapy (RapidArc) is promising since it provides a short treatment time compared with the conventional respiratory gated treatments. In this study, we evaluated the accuracy of the respiratory gated RapidArc treatment. Total sic patient cases were used for this study and each case was planned by RapidArc technique using varian ECLIPSE v8.6 planning machine. For the Quality Assurance (QA), a MatriXX detector and I'mRT software were used. The results show that more than 97% of area gives the gamma value less than one with 3% dose and 3 mm distance to agreement condition, which indicates the measured dose is well matched with the treatment plan's dose distribution for the gated RapidArc treatment cases.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.321-328
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• 2012

The purpose of this study was to examine the toothbrushing behavior of the citizens, their use of dentifrice, awareness of the importance of dentifrice purchase and consciousness of dentifrice containing the extract of Chamaecyparis obtusa in the city of Gwangju. It's basically meant to provide some informations on the development of oral health supplies involving dentifrice containing the extract of Chamaecyparis obtusa in that city in an effort to help the city serve as a hub of the dental industry. The subjects in this study were the selected citizens in the city of Gwangju. As a result of analyzing their awareness of the importance of the considerations for the purchase and use of dentifrice, they gave 68.2% overall. They gave the highest marks of 83.3% to the importance of effect. As for the importance of each item, they gave the highest marks of 85.1% to the importance of the prevention of dental caries. Concerning differences in awareness of the importance of the external purchase factors according to age, every age group placed the most importance on inspection by the certification authorities except for those who were in their 40s and 60s, and the respondents who were in their 40s and 60s attached more importance to price than the other items. Regarding differences in awareness of the importance of effectiveness according to age, those who were under the age of 20 gave the highest marks of 79.8% to the importance of dental-caries prevention and whitening effects. As a result of asking them whether they had an intention to use dentifrice containing the extract of Chamaecyparis obtusa if this dentifrice would be developed, 54.6% replied they had the intention. When they were asked another question whether they thought this dentifrice would have an effect on oral health, 55.1% answered they thought so. 33.8% expected this dentifrice to have a primary effect on the prevention of dental caries. Given the findings of the study, full-scale R&D efforts should be directed into the development of dentifrice containing the extract of chamaecyparis obtusa in the future.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.235-241
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• 2017

This study was carried out to estimate growth characteristics of Kimchi cabbage cultivated in two different growing seasons and three transplanting dates in the greenhouses, and to create a predicting model for the production of Kimchi cabbage based on the growth parameters and climatic elements. Kimchi cabbages were transplanted three times at intervals of two weeks in spring and autumn growing seasons. Sigmoidal models for the estimation of fresh weight (Fw) was designed with days after transplanting, which were Fw=4451.5/[1+exp{-(DAT-34.1)/3.6}]($R^2=0.992$) and Fw=7182.0/[1+exp{-(DAT-53.8)/11.6}] ($R^2=0.979$), respectively. The relationship between fresh weight of Kimchi cabbage and growing degree days (GDD) was highly correlated, and the regression model represented by Fw=4451.5/[1+exp{-(GDD-34.1)/3.6}] ($R^2=0.992$) in spring growing season. The yield of Kimchi cabbage under spring and autumn growing season were estimated 11348.3kg/10a and 15128.2kg/10a, respectively, which were much different than outdoor culture each growing season, while greenhouse cultivation have shown similar results. To estimate the efficacy of prediction yield in Kimchi cabbage, we will need to supplement a predicting model, which was based on the parameters and climatic elements by the field cultivation.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.2
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• pp.1-13
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• 2014

This study is preliminary founding start-ups of restaurant entrepreneurs to study the characteristics of management in order to provide useful information was studied. Survey period is from 2013 March 15 to August 31. About the nature of the preparation and establishment founder findings restaurant entrepreneurs of Western Gyeongnam area were most often in the form of an independent establishment has been compiled, work experience and other industries operating experience was more than restaurant entrepreneurs of operating experience. Hypothesis Testing in accordance with results of this study are as follows. First, the 50 founders than 30 founders quickly when the customer complaint or that service, order food and non-food note is issued after obtaining the order or that provide food, no customer is often inconvenient check the sharing services, such as personnel activities were devoting a lot of effort. Second, the re-startups restaurant entrepreneurs than new startups restaurant entrepreneurs was founded after the founder of career-related customer complaints about food more active coping was, and re-startups restaurant entrepreneurs by the founder other than business founded by the founder of the food-related customer complaints more aggressively for coping, respectively. Third, restaurant entrepreneurs of the store operations management has integrity, words and actions match, such as the degree of belief in the promise of reliability and the possibility of failure, which means the degree of recognition and response efforts are having an impact deal. Fourth, restaurant of food service management services and after-sales service has impact on the founder of the self-efficacy and self-efficacy of pre-service features and reliability founder affecting. Fifth, the revenue of the restaurant for dealing with customer complaints management includes efforts are having an impact. Sixth, restaurant founder of reliability and customer care has influenced the self-efficacy. Seventh, management of operational management activities have a positive impact on business performance are.