• Journal of Radiation Protection and Research
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• v.40 no.1
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• pp.55-64
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• 2015

Dose calculations which are a crucial requirement for radiotherapy treatment planning systems require accuracy and rapid calculations. The conventional radiotherapy treatment planning dose algorithms are rapid but lack precision. Monte Carlo methods are time consuming but the most accurate. The new combined system that Monte Carlo methods calculate part of interesting domain and the rest is calculated by neural can calculate the dose distribution rapidly and accurately. The preliminary study showed that neural networks can map functions which contain discontinuous points and inflection points which the dose distributions in inhomogeneous media also have. Performance results between scaled conjugated gradient algorithm and Levenberg-Marquardt algorithm which are used for training the neural network with a different number of neurons were compared. Finally, the dose distributions of homogeneous phantom calculated by a commercialized treatment planning system were used as training data of the neural network. In the case of homogeneous phantom;the mean squared error of percent depth dose was 0.00214. Further works are programmed to develop the neural network model for 3-dimensinal dose calculations in homogeneous phantoms and inhomogeneous phantoms.

• Journal of The Korean Association For Science Education
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• v.33 no.5
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• pp.1021-1040
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• 2013

In order to explore the influences of coteaching through mentoring upon the teaching professionalism of beginning science-gifted education teachers, this case study deeply investigated the change processes in the aspects of pedagogical content knowledge (PCK). Two beginning teachers planned, performed and reflected together their science instructions for science-gifted students in secondary school during four 3-hour classes. Since the second instruction, pre-, during-, and post-mentoring were conducted, we collected various data related to teachers' planning processes, videotaped all coteaching science classes, and wrote field notes. We also recorded in-depth interviews with the teachers and the whole process of mentoring. All the data were analyzed by using the constant comparative method. The results of the analyses indicated that coteaching through mentoring positively changed the teachers' PCK. Above all, we found that coteaching and mentoring strategies generated a significant synergy effect through a mutually complementary relationship. The teachers developed deep practical knowledge about the enrichment curriculum, which placed more emphasis on developing cognitive and/or affective characteristics of science-gifted students. The teachers also improved their knowledge about the characteristics of science-gifted students and the instructional strategies appropriate for developing them. Moreover, practical knowledge about assessment domains and methods used in science-gifted education were improved. Knowledge on science content necessary for effective inquiry instruction was also improved.

• Journal of The Korean Association For Science Education
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• v.33 no.6
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• pp.1219-1236
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• 2013

The purpose of this study was to investigate the association between subject matter knowledge (SMK) and pedagogical content knowledge (PCK) for science teachers. To this end, a total of 26 secondary Earth science teachers participated in this study and a concept diagnostic questionnaire and a lesson planning task of atmospheric pressure were devised to give an indication of participating teachers' SMK and PCK, respectively. The results of this study are summarized as follows: First, participating teachers showed a variety of SMK levels about atmospheric pressure. Second, teachers at high level of SMK focused on 'supplementary' and 'fundamental' curriculum contents for in-depth conceptual understanding, but teachers at low level of SMK, on the contrary, stressed 'applicative' curriculum contents. Third, teachers at high level of SMK grasped students' misconceptions and difficulties in learning atmospheric pressure far more concretely than teachers at low level of SMK. Lastly, teachers at high level of SMK showed a tendency to use learner-centered instructional strategy by utilizing students' prior knowledge, but teachers at low level of SMK were inclined toward teacher-directed concept explanation. Based on this study, some implications for effective science teacher preparation programs were also discussed.

• Journal of Dental Rehabilitation and Applied Science
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• v.29 no.4
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• pp.418-425
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• 2013

This case report describes about recurrent herpetic stomatitis mimicking post-root resection complication. A 49 year-old male patient was diagnosed vertical root fracture of the mesiobuccal root of his left maxillary first molar (#26). The mesiobuccal root was resected following root canal treatment of the same tooth. 19 months later, the patient presented with pain on left hard palate after a barbecue party. Intra oral examination revealed a gum boil-like blister at the hard palate corresponding to the apex of the palatal root of #26. On clinical examination, there was bleeding on probing and the periodontal pocket depth was measured less than 5 mm with no tooth mobility. On a periapical radiograph, periodontal ligament space widening was observed. Tracing the sinus tract with gutta percha cone was attempted, however, it was impossible. Extending the field of vision, small multiple round ulcerations were observed at the palate front which caused pain to the patient. Therefore, the pain was considered a non odontogenic and the patient was referred to the department of oral medicine. The patient was diagnosed recurrent herpetic stomatitis and after 3 days of antiviral medication, the pain and ulceration were subsided.

• Journal of the Korean Institute of Gas
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• v.16 no.2
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• pp.18-24
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• 2012

This research seeks to evaluate damage on type II gas cylinder by an acoustic emission test when executing 20000 cycles fatigue test and thereafter burst test. Used gas cylinders in the experimental are three types as follows; one is sound cylinder, others are cylinders which contain longitudinal and transverse artificial defect. The size of artificial defect is a depth of 3 mm, width of 3 mm and length of 50 mm. In the case of the cylinder which artificial defect, unlike the expectation that it will burst in low pressure, the burst pressure of the cylinder did not differ much according to whether or not there were defects. However, when there was longitudinal defect, the location of burst was near the location of defect. This leads to the effect in which the thickness of the composite material becomes thinner according to the length of the longitudinal defect and this is judged to have an effect on the location of initiation and growth of crack in the liner. Also, for the acoustic emission signal, when there is longitudinal defect, the ratio of an event occurring at defect position among overall hits is more than 50 %, and the source location also accords very precisely with defect position.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.4
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• pp.73-84
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• 2017

This study started from searching for cause and solution of the part where online shopping malls are easy to start but easy to choose. It is thought that online shopping mall business has sufficient merit in the situation of Korea which is rapidly spreading internet, and it started from the opinion that if it can strengthen the characteristics of successful business start-ups, it can increase the rate of failure and reduce the failure rate. Internet shopping mall education experts gathered and discussed in depth what is the way in which mall entrepreneurs can maintain business continuously. As a result of summarizing the opinions of many shopping mall experts, we concluded that the marketing capabilities of each company should be strengthened. In addition, the importance of entrepreneurship education has emerged. In particular, it has been concluded that strengthening the competence of marketing mix is an important factor that determines the success and failure of the company. In this case, the researchers started to study this question with the question of what factor of marketing 4P has the greatest influence on the success of start-up. I also decided to study the impact of entrepreneurship education. As a result of this study, marketing mix ability as an independent variable has a significant positive effect on the success of entrepreneurship. Especially, the effect of product mix among 4Ps is significant for successful entrepreneurship.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.619-629
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• 2013

The objective of this study is to estimate shear wave velocity of earth dam materials using artificially generated vibration from blasting events and to verify its applicability. In this study, the artificial blasting and vibration monitoring were carried out at the site adjacent to Seongdeok dam, which is the first blasting test for an existing dam in Korea. The vibrations were induced by 4 different types of blasting with various depths of blasting boreholes and explosive charge weights. During the tests, the acceleration time histories were recorded at the bedrock adjacent to the explosion and the crest of the dam. From frequency analyses of acceleration histories measured at the crest, the fundamental frequency of the target dam could be evaluated. Numerical analyses varying shear moduli of earth fill zone were carried out using the acceleration histories measured at the bedrock as input ground motions. From the comparison between the fundamental frequencies calculated by numerical analyses and measured records, the shear wave velocities with depth, which are closely related to shear moduli, could be determined. It is found that the effect of different blasting types on shear wave velocity estimation for the target dam materials is negligible and the shear wave velocity can be consistently evaluated. Furthermore, comparing the shear wave velocity with the previous researchers' empirical relationships, the applicability of suggested method is verified. Therefore, in case that the earthquake record is not available, the shear wave velocity of earth dam materials can be reasonably evaluated if blasting vibration test is allowed at the site adjacent to the dam.

• The Journal of Churna Manual Medicine for Spine and Nerves
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• v.8 no.2
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• pp.67-78
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• 2013

Objectives : The present study examines the domestic trend of Osteoporosis studies in Korea. Method : We reviewed oriental medicine papers published in last ten years (2003-2012). Korean literature search was used for domestic Internet search portal. 'Naver specialized information retrieval', 'Korea Traditional Knowledge Portal', 'Korea Medical Information Portal (OASIS)',' Scientific and Technological Information Integration Services (NDSL)',' Academic Research Information Service (RISS)'as the primary destination of the search were. Since 2003 until 2012, the thesis o'f osteoporosis'and found 92 papers with the search term '(golwi)' to the search terms found in 3 papers Korean medical target of on going research trends in osteoporosis about investigated. Results : 1. We researched 95 papers in 15 journals and patterns of study were as follows : experimental studies were 79(83%), clinical studies were 12(13%), reviewed studies were 3(3%) and etc. were 1(1%). 2. The experimental studies(79) were divided into papers on efficiency testing of herbal medications(67) and herbal acupuncture(12). 3. The clinical studies(12) showed that research has been carried out in the fields of follow up surveys for the herbal medication efficiency testing, basic research, case report, the relativity of osteoporosis to age and sex, and the perception about osteoporosis and korean medicine treatment. 4. The reviewed studies showed that research has been carried out in the fields of osteoporosis about acient literature and domestic studies about herbal medication of osteoporosis. Conclusion : Reviewing the domestic trend of Osteoporosis studies and examining the strong and weak points of those treatments are essential for the future studies. It is anticipated that this review benefits the future in-depth study on the treatments for osteoporosis in Korean medicine.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.2
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• pp.585-594
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• 2013

In this study, laboratory experiments and numerical simulations were conducted to test the performance of resonance power buoy system proposed by Kweon et al.(2010). The system is composed of a linear generator and a mooring buoy. The mover of the linear generator mainly has heave motion driven by vertical oscillation of the buoy. In this system, the velocity discrepancy between the mover and the buoy makes electricity. However, ocean wave energy as a natural resource around Korean peninsula is comparatively small and the driving force for producing electricity is not enough for commercialization. Therefore, it is necessary that the buoy motion be amplified by using resonance characteristics. In order to verify the resonance effects on the test power buoy, the experimental investigations were conducted in the large wave flume (length of 110 m, width of 8 m, maximum depth of 6 m) equipped with regular and random plunger wave generator. The resonance draft of test power buoy is designed for the corresponding period of incident wave, 1.96 sec. Regular wave test results show that the heave response amplitude operator(RAO) by a test buoy has the amplification of 5.66 times higher compared to the wave amplitude at the resonance period. Test results of random waves show that the buoy has the largest spectrum area of 20.73 times higher at the point of not the resonance period but the shorter one of 1.85 sec. Therefore this study suggests the resonance power buoy for wave power generation for commercial application in the case of the coastal and oceanic area with smaller wave energy.

• Journal of Advanced Marine Engineering and Technology
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• v.37 no.2
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• pp.242-251
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• 2013

Recently, while global concern over offshore resources exploration and development is being increased rapidly, offshore plant industry is highlighted as an industry of high added value. Along with this global trend, domestic concern over offshore plant development is being increased as well. In the overseas case, a marine geotechnical survey guideline for confirming characteristics of seabed sediments is available at the time of installation of offshore plant but such guideline is not available in our country. In this study, survey techniques fit for domestic marine environment was applied according to overseas guideline at southern coastal area, Korea. Among the marine geophysical survey techniques being proposed abroad, magnetic survey and seabed photograph were excluded. However, highly reliable data analysis was enabled for marine geophysical survey, which includes in-situ coring investigation and laboratory soil test. In addition, continuous ocean current survey was included to find scour potential due to the current around the offshore plant. Although coring depth is not so deep, we predicted geological structure through the analysis of amplitude features of seismic data. Characteristics of seabed sediments cold be obtained regionally and directly through combined analysis of marine geophysical survey data and coring data.