• Journal of Korean Society of Forest Science
• /
• v.96 no.4
• /
• pp.477-482
• /
• 2007

Forest biomass became a topic because we have growing interest in global environmental issues and environment-friendly energy resources. This study was carried out to estimate the forest biomass and develop a program for biomass information management in Korea. The total forest biomass (million ton) were 521 for gross forest, 403 for productive forest and 201 for commercial forest in 2005. Also, the annual biomass production in forest was 20 million ton which was equivalent to 94,290 Gkcal of heating value and about 9 billion won of paraffin oil. The biomass growing rate (every 10year) increased from 4.95% in 1985 to 5.30% in 1995 but turn down 4.46% in 2005. The factors that the forest stock could be converted to the forest biomass have developed according to forest type. Therefore, it is impossible to estimate the exact biomass by tree species. In this reason, the demands of the development of the factors by tree species was raised. In addition, it is on time to develop an equation for estimation of biomass by species using dbh and height as independent factors.

• Management & Information Systems Review
• /
• v.36 no.5
• /
• pp.99-120
• /
• 2017

Recent studies shows that international entrepreneurship orientation is recognized as a very important tool for improving corporate performance in international business activities. However, these relationships show various research results. Therefore, it can be a very interesting research topic to examine whether these relationships are linear or non-linear when selected as a target in developing country like China. The purpose of this study is to examine whether the effects of international entrepreneurship orientation on the export performance is non-liner type in China's manufacturing firms. And investigated the moderating role of degree of internationalization and market dynamism relative to the relationship between the international entrepreneurial-orientation and the export performance. A total of 478 questionnaires were used for the hypothesis test. The results of this study are summarized as follows: First, there is a J-shaped. relationship between international entrepreneurship orientation and export performance. Second, degree of Internationalization strengthened the reverse J-shaped relationship between international entrepreneurship orientation and export performance. Finally, degree of internationalization and market dynamics show that J-shaped relationship between international entrepreneurial orientation and export performance is strengthened. The results of the study's theoretical contribution and the managerial contribution is as followed. As a theoretical contribution, it is confirmed that international entrepreneurial orientation (J-shaped) and export performance form a non-linear relationship, and it is possible to make an empirical contribution that can newly approach the relationship between international entrepreneurial orientation and export performance. The managerial contribution suggests that China's exporting companies have a higher degree of Internationalization in their international business activities and that the higher the dynamics of the overseas markets, the more advanced the international entrepreneurial behavior should be required to improve the export performance.

• The Journal of Korean Academy of Prosthodontics
• /
• v.41 no.6
• /
• pp.732-746
• /
• 2003

Statement of problem. Soft lining materials, also referred to as tissue conditioning materials, tissue heating materials, relining materials, soft liners or tissue conditioners, were first introduced to dentistry by a plastic manufacturer in 1959. Since the introduction of the materials to the dental field, their material properties have been continually improved through the effort of many researchers. Soft lining materials have become widely accepted, particularly by prosthodontists, because of their numerous clinical advantages and ease of manipulation. Unfortunately, few reports have been issued upon the topic of increasing the bond strength between the base metal alloy used in cast denture bases and PMMA soft liner modified with 4-META, nor upon the pattern of debonding and material change in wet environment like a intra oral situation. Purpose. The purposes of this study were comparing the bond strength between base metal alloy used for the cast denture bases and PMMA soft liner modified with 4-META, and describing the pattern of debonding and material property change in wet environment like the intraoral situation. Material and Methods. This study consisted of four experiments: 1. The in vitro measurement of shear bond strength of the adhesive soft liner. 2. The in vitro measurement of shear bond strength of the adhesive soft liner after 2 weeks of aging. 3. A comparison of debonding patterns. 4. An evaluation the Relation time of modified soft liner. The soft liner used in this study was commercially available as Coe-soft (GC America.IL.,USA), which is provided in forms of powder and liquid. This is a PMMA soft liner commonly used in dental clinics. The metal primer used in this study was 4-META containing primer packed in Meta fast denture base resin (Sun Medical Co., Osaka, Japan). The specimens were formed in a single lap joint desist which is useful for evaluating the apparent shear bond strength of adhesively bonded metal plate by tensile loading. Using the $20{\times}20mm$ transparent grid, percent area of adhesive soft liner remaining on the shear area was calculated to classify the debonding patterns. To evaluate the change of the initial flow of the modified adhesive soft liner, the gelation time was measured with an oscillating rheometer (Haake RS150W/ TC50, Haake Co., Germany). It was a stress control and parallel plate type with the diameter of 35mm. Conclusion. Within the conditions and limitations of this study, the following conclusions were drawn as follows. 1. There was significant increase of bond strength in the 5% 4-META, 10% 4-META containing groups and in the primer coated groups versus the control group(P<0.05). 2. After 2 weeks of aging, no significant increase in bond strength was found except for the group containing 10% 4-META (P<0.05). 3. The gelation times of the modified soft liner were 9.3 minutes for the 5% 4-META containing liner and 11.5 minutes for the 10% 4-META liner. 4. The debonding patterns of the 4-META containing group after 2 weeks of aging were similar to those of immediaely after preparation, but the debonding pattern of the primer group showed more adhesive failure after 2 weeks of aging.

• Journal of Periodontal and Implant Science
• /
• v.37 no.4
• /
• pp.825-838
• /
• 2007

Endosseous implants are used in the treatment of various types of tooth loss, and numerous long-term studies have demonstrated the excellent reliability of this method of treatment. However, the increase of implant failure are associated with inadequate quality and/or height of bone. At the end of the 1980s, Wide(>3.75mm) implants were initially used for managing these difficult bone situations. The recommended indications for its use included poor bone quality, inadequate bone height. immediate placement in fresh extraction sockets, and immediate replacement of failed implants. At the 2000s, wider implants(6.0mm and 6.5mm) were used in a few studies. Although good clinical outcomes have been reported in recent years, there is still a controversy on this topic. Therefore, the purpose of this study was to estimate the survival rate of wide implants($6.0{\sim}8.0mm$) in molar regions, evaluating the clinical outcome. In this study, 1135 RBM surfaced wide implants($Rescue^{TM}$, MEGAZEN Co., Korea/595 maxillary, 540 mandibular) were placed in 650 patients(403 male, 247 female/age mean: $51.2{\pm}11.1$ years, range 20 to 83 years). Of the total, 68.3% were used to treat fully or partially edentulous situations, including single-tooth losses and 31.7% were placed immediately after teeth extraction or removal of failed implants, of which all were in the molar regions. Implant diameter and length ranged from 6.0 to 8.0mm and from 5.0 to 10.0mm respectively. The implants were followed for up to 42 months (mean: $14.6{\pm}9.5$ months). Of 1135 placed implants, 58 implants were lost. Among them, 53 implants were lost within 12 months after implant placement. The survival rate was 93.6% in the maxilla and 96.3% in the mandible, yielding an overall survival rate of 94.9%, for up to 42 months. As the result of Cox regression model, prosthetic type, sinus graft, and patient gender have an statistical significance on the implant survival rate in this study. This study suggests that the use of wide implants($6.0{\sim}8.0mm$) would provide a predictable treatment alternative in posterior areas.

• Asia pacific journal of information systems
• /
• v.19 no.4
• /
• pp.149-176
• /
• 2009

In the recent e-learning environment, avatars are often used to help learners get familiar with the contents, which is ultimately to motivate them to study more. Therefore, it is important to investigate whether avatars have actually the desirable effect on users of e-learning materials. Surprisingly, however, no extensive study has been conducted on this crucial issue Accordingly, main objectives this study are summarized as follows. First, we need to gain better understanding of how much learners' trust towards avatars (termed as "avatar trust") is transferred to learners' trust towards e-learning contents (termed as "contents trust"). Second, we need to investigate how much learners' personal relationships with avatars as well as learning behaviors change depending on avatar types (attractive vs. professional) and contents complexity (easy vs. difficult). As described in the study objectives, in order for us to analyze empirical data more systematically, we classified avatar types into two: "attractive" and "professional;" the contents are categorized as either "easy" or "difficult." Therefore, it is essential for this study to build a prototype e-learning website on which our research purpose can be realized and tested effectively with proper avatar types and e-learning contents. For this purpose, we built a prototype e-learning website, in which avatars are invited from currently working avatar instructors used in real-world e-learning websites, and e-learning contents are adapted from real-world contents about Java programming topic, which have been proved to have shown high quality and reliability. Our research method includes questionnaire survey by inviting a number of valid respondents comprised of office workers who are believed to have high demands for the e-learning contents as well as those who have previous experience with avatar instructors. Respondents were given one of the four e-learning experiment conditions (2 avatar types x 2 contents types) on a random basis. Each experimental e-learning condition is framed to have the same quality but different avatar type and content complexity. Then the respondents are asked to fill out the survey form which has questions about avatar trust, contents trust, personal relationships with avatar, and learning behavior, among others. Regarding the constructs used in research model, we based them rigorously on previous studies. For example, we used six constructs such as behavior to give information (BGI), behavior to obtain information (BOI), need for inclusion wanted, need for control wanted, contents trust, and avatar trust. To measure them, 7-Likert scales were used in the questionnaire. E-learning performance was measured indirectly through two constructs such as BGI and BOI. Six constructs used in the research model were adopted and revised from the FIRO-B model suggested by Schutz. Empirical results are as follows: First, professional avatars are more effective for difficult contents, while attractive avatars were not as effective for easy contents. Second, our study results ascertained that avatar trust transfers to contents trust regardless of avatar types and contents complexity.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.2
• /
• pp.577-586
• /
• 2021

This study analyzed the research trends related to parenting stress of parents with infancy. To this end, 82 papers in journals registered in the KCI from 1998 to 2019 were reviewed. The frequency and percentage were calculated and analyzed for each research period, research topic, research type, and research subject. The research results were as follows. First, from 1998 to 2019, there was a continuous increase in each period. Second, regarding the research subject, the themes related to parents were the most researched, followed by the child, parenting environment, and parent-child. Among the topics related to parents, research on the variables related to parenting beliefs and behaviors was the highest. Third, quantitative research was absolute, and no qualitative research was conducted. Among the quantitative studies, the most common test method was through a questionnaire. Fourth, regarding each research subject, the research of mothers was dominant, followed by mother-infant, parent, and parent-infant-teacher. This study is significant because it provides an opportunity to broaden the scope of research and academic interest in the parenting stress of infancy parents.

• The Journal of the Korea Contents Association
• /
• v.22 no.6
• /
• pp.35-44
• /
• 2022

In this study, we tried to confirm the characteristics of books published on the topic of international cooperation, what kind of international cooperation-related research is being conducted through this book, and what are the main contents of international cooperation. In order to achieve this research purpose, we conducted data construction, statistical analysis, and text mining based on textom in international research cooperation at home and abroad. As a result of the study, it can be seen that there has been a particularly high interest in international research and international cooperation since the 2010s. Through this, it was found that he is interested in development, economy, technology, development, region, and relations and wants to promote development. In addition, topics such as environment, trade, education, and society appeared, and interest in international research cooperation centered on environment, trade, and education was high, was found to have a high influence on society as a whole. Through this study, we find the research significance in that it can serve as a basic research to confirm the characteristics of some national and public research institutes participating in international research cooperation, and that it confirms the trend of participating in international research cooperation in a relatively specific type of institution. can see.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.28 no.4
• /
• pp.549-566
• /
• 2022

Recently, artificial intelligence (AI) technology has progressed rapidly, and industries using this technology are significantly increasing. Further, analysis research using text mining, which is an application of artificial intelligence, is being actively developed in the field of social science research. About 125 laws, including joint laws, have been enacted under the Ministry of Oceans and Fisheries in various sectors including marine environment, fisheries, ships, fishing villages, ports, etc. Research on the laws under the Ministry of Oceans and Fisheries has been progressively conducted, and is steadily increasing quantitatively. In this study, the domestic research trends were analyzed through text mining, targeting the research papers related to laws of the Ministry of Oceans and Fisheries. As part of this research method, first, topic modeling which is a type of text mining was performed to identify potential topics. Second, co-occurrence network analysis was performed, focusing on the keywords in the research papers dealing with specific laws to derive the key themes covered. Finally, author network analysis was performed to explore social networks among authors. The results showed that key topics have been changed by period, and subjects were explored by targeting Ship Safety Law, Marine Environment Management Law, Fisheries Law, etc. Furthermore, in this study, core researchers were selected based on author network analysis, and the tendency for joint research performed by authors was identified. Through this study, changes in the topics for research related to the laws of the Ministry of Oceans and Fisheries were identified up to date, and it is expected that future research topics will be further diversified, and there will be growth of quantitative and qualitative research in the field of oceans and fisheries.

• Journal of Korean Library and Information Science Society
• /
• v.53 no.2
• /
• pp.189-214
• /
• 2022

The purpose of this study is to provide an understanding of the current status of picture book-related research in Korea. For this purpose, 1,660 picture book-related research papers produced in Korea by 2021 were analyzed. The results revealed through the analysis are summarized as follows. First, research papers began to appear in the mid-1990s and began to increase significantly around 2010. Second, the journal with the most research papers was 『Journal of Children's Literature and Education』, accounting for 17.7% of the total. Third, the representative researchers who led the production of the papers are Eun-Ja Hyun and Hea-Sook Jo. Fourth, by research type, individual research papers accounted for 39% and joint research 61%. Fifth, as a result of the analysis of the research topic, the study of the contents (analysis) of picture books (33.4%), the study of the effect of picture books (29.6%), and the study of perception, reaction, and experience of picture books (18.0%) were in order. Sixth, as a result of the research method analysis, experimental studies (35.7%), content analysis (33.7%), literature studies (13.3%), and qualitative studies (9.3%) were in order. Based on the results of the analysis, the researcher suggested diversifying the research production route, expanding the trend of collaboration between universities and the field, diversifying research topics, and enhancing the validity and diversity of research methods.

• The Journal of the Korea Contents Association
• /
• v.22 no.9
• /
• pp.570-582
• /
• 2022

Nucleoplasty is a type of percutaneous disc decompression that has been developed to treat herniated intervertebral discs. Currently, in some clinics, researchers have also applied this procedure to patients with internal disc disruption, apart from the originally intended usage on herniated intervertebral discs. The purpose of this study is to evaluate the feasibility of this extended use based on medical logic. To achieve this, the author analyzed case studies on performing nucleoplasty on patients with internal disc disruption. The main points of the analysis are, first, the validity of the treatment evidence presented by the researchers and, second, the relevance of the patient selection criteria. As a result, it is judged that the therapeutic rationale of existing papers applying nucleoplasty to the treatment of internal disc disruption is unclear or inconsistent with general medical logic, and in the process of patient screening, discs that may be deemed inappropriate for percutaneous decompression are included. Therefore, the author believes that existing studies applying nucleoplasty to the treatment of internal disc disruption have the nature of somewhat adventurous experiments that are unnecessary or can cause potential side effects. In order to uphold patients' rights and improve the completeness of the study in the research process on this topic, the author thinks that it is essential to establish clearer therapeutic evidence than the current level of understanding and to have an elaborate patient screening process based on it.