• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.241-246
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• 2001

Single or dual ion implantations were performed onto the transparent polyethylene terephthalate(PET) sheet, and the surface hardness and the light transmittance in the visual-UV range were examined. Nanoindentation showed that the surface hardness was the highest at about 50 nm depth from the surface and was increased by about 3 times when nitrogen ions were implanted with energy and dose of 90 keV and $1\times10^{15}\textrm{/cm}^2$ respectively. When dual ions such as He+N and N+C ions were implanted into PET, the hardness was increased even more than the case only N ions were implanted. Especially, when PET were implanted with N+C dual ions, the surface hardness of PET increased 5 times more as compared to when implanted with N ions alone. The light at the 550 nm wavelength(visual range) transmitted more than 85%, which is close to that of as-received PET, and at the wavelength below 300 nm(UV range) the rays were absorbed more than 95% as traveling through the sheet. implying that there are processing parameters which the ion implanted PET maintains the transparency and absorbs the UV rays. It can be considered that the increase in the hardness of polymeric materials is attributed to not only cross linking but also forming hard inclusions such as hard C-N compounds, as evidenced by the formation of the highest hardness when both N and C ions are implanted onto PET.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.1
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• pp.299-324
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• 2018

This study analyzes the processes and the needs of public library services for multicultural populations based on cooperation between public libraries and local organizations. In-depth interviews with public librarians and officers of local organizations were conducted for this case study. Result shows that cooperation was inevitable because there was not enough library personnel compared to the amount of services they have to provide, and the librarians did not have proper skills to serve the diverse populations. Public libraries were cooperating with many local organizations including the Multicultural Family Support Center. Gatekeepers of ethnic communities were playing important roles in promoting and inviting participants for library programs. Many children and young adults with immigration background gained positive views on reading and libraries after participating library programs based on cooperation between public libraries and local organizations, which was recognized as the best achievement of cooperation by many interviewees. Despite many good results of cooperation, how to get to the majority of diverse populations who are not library users yet is still a question mark. Interviewees for this study all agreed that current library service has limitations and insisted a whole new method to invite immigrants and their families to public libraries should be created.

• Journal of the Economic Geographical Society of Korea
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• v.19 no.2
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• pp.242-264
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• 2016

Tourism is a major sector of the national and regional economy in Southeast Asia endowed with rich natural environment and a variety of cultural and historical heritages. Tourism has been recognized as the industry without chimneys. However, as tourism sector is getting larger and being globally standardized, various problems such as environmental degradation as well as profits leakage from locals have been gradually aggravated. Against negative impacts from massive tourism various efforts have been tried and community-based ecotourism(CBET), seeking environmental conservation and community development at the same time, has emerged as a noteworthy alternative. By comparing the two cases of CBET in Indonesia and Cambodia, this paper aims to review the current status and future challenges of community development through ecotourism in Southeast Asia's rural villages. In the concrete, this paper analyses in-depth on case of JED(the village ecotourism network) in Bali, Indonesia and CBET project in Ramsar wetland reserves of Steung Treng province, Cambodia and founds out the possibility and main obstacles of community developmental strategy through CBET. Both cases have proven the positive outcomes in terms of environmental protection, local people's awareness improvement, and direct/indirect economic gain from CBET project. However, there are significant, but differentiated limitations in management capacities and stabilities of internal governance of two villages. Both villages are still in need of brisk networks with and assistance from the outside. In the conclusion part, this paper suggests CBET development program in Southeast Asia through Korea's social enterprises as one of the possible ODA programs(in tourism sector).

• Journal of the Economic Geographical Society of Korea
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• v.19 no.2
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• pp.225-241
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• 2016

This paper looks into the process of the formation of a Chinese ethnic place in Jayang-dong, Gwangjin-gu. In doing so, the paper reviews Chinese immigrants with the approach of cultural adaptation. Specifically, in-depth interviews with both Chinese immigrants and Korean native people in Jayangdong has been conducted to analyze the local residents' reaction to the Chinese immigrants, the conflicts between the natives and the Chinese immigrants, and communications among them. Based on the analyses, the paper recognizes the change of relationship between the natives and the Chinese immigrants in the development of the ethnic place. The relationship between the Korean native people and Chinese immigrants in Jayang-dong turns out to be more positive than that in other Chinese towns. In Jayang-dong, in the early period of the formation of the area, the Korean native people and Chinese immigrants used to have conflicts. However, as time goes by, the conflicts has been resolved and they have embraced each other through interchanges between them based on mutual understanding and consideration. Cultural adaptation in Jayang-dong has occurred in the way that the immigrants have been integrated into the mainstream society based on the connectedness with both the native people and immigrants embracing each other.

• Journal of Periodontal and Implant Science
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• v.34 no.3
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• pp.563-572
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• 2004

Since bacterial plaque is known as the major cause of every oral disease, it is necessary to control plaque to maintain periodontal health. Although tooth brushing has been the typical method of plaque control, additional use of plaque control devices are necessary for cleansing interdental areas. Dental floss has been used for a long time as the additional plaque control device and proved to be effective. The newly developed embossed new dental pick is composed of elastic plastic material in form with its tip longer than other toothpick. In addition, as thickness of the tip gradually increases, it can be adapted easily with minimal trauma to interdental gingiva. The embossed tip can remove dental plaque easily, and the opposite end can approach lingual and palatal areas through triple angulation. Therefore, the authors studied the effect of embossed new dental pick and dental floss on periodontally involved 15 patient. The following results were obtained. 1. For embossed new dental pick, probing depth at baseline, 1 week, 4 weeks were $3.6{\pm}0.6mm$, $3.4{\pm}0.5mm$, $3.2{\pm}0.5mm$, respectively, and $4.2{\pm}0.9mm$, $4.1{\pm}0.9mm$, $4.0{\pm}0.9mm$, respectivly for clinical attachment level. 2. In case of embossed new dental pick, bleeding on probing at baseline, 1 week, 4 weeks were $43.0{\pm}4.4%$, $28.5{\pm}5.1%$, $22.2{\pm}5.6%$, respectively, and, at 1 week and 4 weeks, they were significantly different from that of dental floss. 3. Gingival index of toαhpick at baseline, 1 week, 4 weeks were $1.7{\pm}0.5$, $1.0{\pm}0.3$, $0.9{\pm}0.2$, respectively, and, $1.7{\pm}0.5$, $1.1{\pm}0.4$, $1.0{\pm}0.4$, respectively for plaque index, and $3.0{\pm}0.5$, $1.7{\pm}0.5$, $1.4{\pm}0.4$, respectively for proximal plaque index. proximal plaque index at 4 weeks was significantly different from that of dental floss. 4. The result of questionnaire showed that the two types of device were both satisfactory, however, embossed new dental pick had higher preference as well as satisfaction. As a result, embossed new dental pick is thought to be clinically effective for its simplicity and good accessibility.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.4
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• pp.517-523
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• 2000

Nasopharyngeal closure is a sphincter mechanism between the activities of the soft palate, lateral pharyngeal wall and the posterior pharyngeal wall, which divides the oral cavity and the nasal cavity. It participates in physiological activities such as swallowing, breathing and pronunciation. In case of an error in this mechanism, it is called a nasopharyngeal incompetence. The causes of this error are defects in (1) length, function, posture of the soft palate (2) depth and width of the nasopharynx, (3) activity of the posterior and lateral pharyngeal wall. The purpose of this study is to analyze the nasopharynx of cleft palate patients using lateral cephalograms and at the same time, evaluate the degree of hypernasality of each vowels to find its relationship with nasopharyngeal incompetence. The following results were obtained: 1. The length of the soft palate was markedly short than normal. 2. The adequate ratio was smaller than the normal value. 3. As the adequate ratio decreased, when articulating vowels, anatomic mVPI increased. 4. When articulating each vowels, anatomic VPI was in proportion with the degree of hypernasality. 5. The degree of hypernasality was greater in high vowels(/i/, /u/) than low vowel(/a/). From the above results, it can be concluded that in cleft palate patients, lateral cephalograms can be used effectively in diagnosing and evaluating nasopharyngeal incompetence. The anatomic structure of the nasopharynx has close relation to the degree of hypernasality.

• 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.