• Journal of the korean academy of Pediatric Dentistry
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• v.29 no.2
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• pp.189-195
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• 2002

In the area of pediatric dentistry, several behavior modification techniques have been attempted to relieve young patients' dental fear. The use of audio-visual(AV) aids is one of them and is increasing. In this study, several patients' reactions to dental treatment have been investigated after using AV aids, including patients' sleep, movement, crying and overall behavior. The effectiveness of AV aids have also been investigated through patients' age, previous dental experience and daily exposure to TV or video. Thirty healthy children with Frankl behavior rating (+) or (-) were included in this study. The average age of the children was $52.9{\pm}12.7$ months and no statistical difference was found between the two groups. Thirty patients were equally divided into two groups. Group I(control) received dental treatment with the conventional tell-show-do while group II(AV) with tell-show-do and AV aids. All patients received only restorative dental treatment and received no extraction. Houpt behavior rating scale was used to evaluate patients' behavior during the dental treatment. As a result, there was no significant difference between the two groups in movement and crying. However, more patients in the AV group fell asleep during the dental treatment compared to the control group. Within the AV group, patients with previous dental experience, older age and frequent exposure to AV materials showed better overall behavior during the dental treatment as audio-visual aids were used for behavior management.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.3
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• pp.33-39
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• 2011

The purpose of this study is to present the raw data for establishing the conservation and restoration trail about Wolseong by objective and systematical trail deterioration in Wolseong as UNESCO, world heritage site, Gyeongju-si, Korea. To accomplish the purpose, not only trail condition such as altitude, entire width, bare width, maximum depth and slope of trail, but also deterioration types of trail were surveyed at the total 97 points for 2.145km in length on the 11 access trails to Wolseong. Major deterioration types of trail were root exposure(48%), rock exposure(40%), trail deeping(9%) in order of frequency. To grasp the deterioration condition of the trail, assessment on impact rating class of trail that the 11 access trail were investigated. Putting these results together informs us that the deterioration condition of the trail in Wolseong is reached the level of grave concern yet, prompt countermeasure to maintain the existing condition has to be considered with regard for the conditions of location and the containing amounts of use.

• East Asian Journal of Business Economics (EAJBE)
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• v.6 no.3
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• pp.1-15
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• 2018

Purpose - This study investigates the effect of MNEs' characteristics on the use of foreign currency denominated debt in the context of Korean firms. This study examines the relationship between MNEs and the use of foreign debt focusing on the accessibility to the capital market in addition to the motive of hedging against foreign exchange exposure. Research design and methodology - Probit estimation is employed for estimating significant factors in determination of the use of foreign debt by firms. The dependent variable is a dummy variable to indicate whether a firm uses foreign debt or not at the end of 2004. Independent variables include foreign subsidiaries ratio, export to sale, R&D expenditure to sale, and credit rating. Results - The results show that the interaction between the level of internationalization represented by intra-regional diversification and the strategic characteristics embedded in the region of entry affects the use of foreign debt. In case of a high level of diversification within the developing region with a strong pursuit of asset exploitation, MNEs are more likely to use foreign debt, whereas a high level of diversification within the developed region with a strong pursuit of asset seeking, MNEs are less likely to use foreign debt. Conclusions - The differences between MNEs in terms of intra-regional diversification, strategic orientation, and the accessibility to capital markets as well as the hedging motive affect the use of foreign debt.

• Journal of Periodontal and Implant Science
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• v.26 no.1
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• pp.230-243
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• 1996

Root surface exposure due to gingival recession after periodontal surgery, dentin exposure after root planing elicit pain response when exposed to mechanical, heat, chemical or osmotic stimulation. Especially, patients treated with periodontal surgery, show high frequency and there have been reports showing the 1 out of 7 patients have dentin hypersensitivity. There have been many studies on the clinical effects of various materials on the treatment of dentin hypersensitivity. but, none could provide absolute clinical efficacy. In this study, 45 teeth from 30 patients, who had had periodontal surgery and showed dentin hypersensitivity after surgery were chosen for the experimental group and they were illuminated with laser, 15teeth were chosen for the control group and they were not exposed to laser. After this dentin hypersensitivity was elicited by tactile, compressed air, cold water and then, the degree was evaluated using NRS(Numerical Rating Scale). And during LLLT(Low Level Laser Therapy) semiconductor laser using Gallium - Arsenide as a diode was illuminated for 180 seconds at a frequency of 7(500Hz). This therapy was done 10 times, and each time the changes in dentin hypersensitivity was evaluated using NRS. The results were as follows : 1. After treat with LLLT on dentin hypersensitivity due to periodontal surgery, 22.2% showed total loss of dentin hypersensitivity, 60.0% showed loss of tactile dentin hypersensitivity, 48.8% showed loss of compressed air dentin hypersensitivity, 22.2% showed loss of cold water dentin hypersensitivity. 2. As a result of clinical evaluation of dentin hypersensitivity using NRS, there was significant increase in improvement of dentin hypersensitivity in the experimental group compare to the control group(P<0.05). And there was almost no natural loss of dentin hypersensitivity in the control group. 3. In comparison of the stages of evaluation, there was significant difference in between experimental and control group. after the second visit(P<0.05), and the difference increased with each visit.

• Korean Journal of Environment and Ecology
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• v.29 no.4
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• pp.605-614
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• 2015

This study was carried out to maintain, manage and restore the trails by assessing the physical conditions, the patterns of deterioration and the impact rating class of the major trails of Juwangsan National Park. The major trails followed 4 routes including Jubong, Gamaebong, Janggunbong~Geumeungwangi and Woloe. The route length of Jubong was 4.6 km; it was 3.6 km for Gamaebong, 5.6 km for Janggunbong~Geumeungwangi and 5.9 km for Woloe. As for the physical conditions, Jubong was the widest and Janggunbong~Geumeungwangi was the narrowest in trail width. In terms of the bared trail width, Jubong was the widest and Janggunbong~Geumeungwangi was the narrowest. As for the depth of erosion, Gamaebong was the deepest and Woloe was the shallowest. Janggunbong~Geumeungwangi was the steepest and Gamaebong was the gentlest in the slope. Further, Gamaebong showed the highest soil hardness, and Woloe had the lowest hardness. In terms of the times of appearance of deterioration patterns, Jubong recorded 71 times, Gamaebong 62 times, Janggunbong~Geumeungwangi 63 times and Woloe 78 times. In case of the impact rating class, the trail erosion was similar to grades I and II grade; the rest were mostly I grade and hence considered to be in a generally good condition. For the ongoing management of trails, a comprehensive study needs to be conducted in the light of various environmental factors. Also, a restoration plan for damaged trails should be established with consideration for the surrounding environment and ecosystem.

• Korean Journal of Optics and Photonics
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• v.11 no.6
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• pp.429-433
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• 2000

A study of the tunable fiber DFB laser using PZT-stretcher is presented. The device has an laser ocsillator by using a fiber Bragg grating at 1559.4 nm written directly into a 3-cm long $Er^{3+}$ doped fiber. Post UV-exposure method to provide the necessary phase shift is used for a single mode operation. The device shows the single mode operation of $230\muW$ output power and has a narrow linewidth of 35 kHz. The lasing wavelength of the laser can be tuned in a range of 3 nm by stretching the grating.rating.

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.71-77
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• 2003

Purpose : To evaluate and compare the efficacy of digital radiographic images in the detection of bone loss at the bifurcation area of the mandibular first molar with traditional film-based periapical radiographs, Materials and Methods : One dried human mandible with minimal periodontal bone loss around the first molar was selected and an artificial alveolar bone defect at the bifurcation area was serially prepared over 18 steps. Images were taken using a direct CCD-based system and with F-speed periapical films. The images were evaluated by seven interpreters (3 radiologists, 3 periodontologists, and 1 general dentist) using a 5-point confidence rating scale. Results : The readability of both periapical radiographs and digital image increased as the size of the artificial lesion and exposure time increased (p < 0.05). Periapical radiographs offered greater readability of smaller bone defects than digital images, and the coefficient of variation of mean score between periapical radiographs and digital images showed a significant difference. Conclusion : The experimental results indicate that a significant difference in the coefficient of variation of mean score exists between periapical radiographs and digital images, and that traditional film-based periapical images offer greater readability of smaller bone defects than digital images can presently offer.

• The Journal of Information Systems
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• v.31 no.2
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• pp.159-177
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• 2022

Purpose Online reviews are critical for sales of online shopping platforms because they provide useful information to consumers. As the eCommerce market grows rapidly, the role of online reviews is becoming more important. The purpose of this study is to analyze how online reviews written by domestic consumers affect product sales by classifying the types of products. Design/methodology/approach This study analyzed how the effects of review characteristics(reviewer reputation, reviewer exposure, review length, time, rating, image, and emotional score) on the usefulness of online reviews differ depending on the product types. Subsequently, how the impact of review attributes (review usefulness, number of reviews, ratings, and emotional scores) on product sales differs according to each product type was compared. Based on the FCB Grid model, the product type was classified into high involvement-rational, high involvement-emotional, low involvement -rational, and low involvement-emotional product types. Findings According to the analysis result, the characteristics of reviews useful to consumers were different for each product type, and the review attributes affecting product sales were also different for each product type. This study confirmed that it revealed that product characteristics are major consideration in evaluating the review usefulness and the factors affecting product sales.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.551-557
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• 2016

National competency standards, which are the contents of the knowledge, skills and attitudes required to perform a job in industry, is organized by the country. the job performance was evaluated based on the National competency standards from the third-year grade of radiology students by using field-based training courses. according to the evaluation results, students showed over 93% satisfactory ratio of job performance in all radiography projection methods. Therefore, it can be predicted that field-based training courses for students made a positive effect on improving their job performance. Exposure methods with CR equipment were evaluated the best rating, yet it has various problems. The standard deviation between students was very high, and the CR operation skill of students was insufficient. Film methods was evaluated also showed problems, due to the exposure condition setting and developing operation. although DR method was rated good to the students, it was evaluated that the operation skill of DR and the ancillary equipment operation skill was shortage. By supplementing the evaluation factors below proficiency levels to a course management in each exposure method, it could help students course achievement. Also, it could help students to improve job performance of clinical areas after graduation.

• Journal of Conservation Science
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• v.30 no.4
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• pp.353-364
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• 2014

Formaldehyde(HCHO) may have a damage effect on Korean traditional textiles, because concentration is high and occurrence frequency is frequent at the exhibition room and storage area. Total 20 specimens were prepared using 4 different materials (silk, cotton, ramie, hemp) after dyeing with 5 colors (undyed, red, yellow, blue, black). The specimens were exposed to HCHO gas in the test chamber. The gas acceleration test was conducted to identify the deterioration of Korean traditional textiles according to HCHO concentration(0.5, 1, 10, 100, 500ppm), to temperature-humidity condition at HCHO 500ppm, and deterioration conditions at HCHO 500ppm. Optical, chemical, and physical evaluation was carried out after the exposure. The results, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased at 500ppm, while pH decreased at 500ppm. Also, color difference, grey scale rating, formate($HCO_2{^-}$) of some textiles increased double damage at high temperatures & humidity, high humidity condition. But, damages of accelerated degradation textiles were slight, because of degradation degree and degradation products. The results suggest that determined the damage to the korean traditional textile, damage level, damage-weighted condition, damage to accelerated degradation textiles. In addition, formaldehyde damaged to yellowing of red textiles, bleaching of accelerated degradation textiles, formic acid damaged to bleaching of total 20 specimens.