• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.4
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• pp.232-241
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• 2020

Purpose: This study investigated the complications and patterns of implants that confronted with the extruded natural teeth. Materials and Methods: Among patients who received implant treatment between 2006 and 2018 at Chosun University Dental Hospital, only implants that had a maintenance period of at least 5 years and that both implants and confronting natural teeth could be measured and compared on a radiograph were selected. They were divided into two groups. Group 1, experimental group consisted of Implants confronting the extruded natural posterior teeth (n = 167: maxilla (Group 1max) = 92, mandible (Group 1man) = 75) and Group 2, control group consisted of Implants confronting the normal natural posterior teeth (n = 656: maxilla (Group 2max) = 272, mandible (Group 2man) = 384). Results: The incidence of complications between Group 1 and Group 2 was statistically significant. In particular, there was a statistically significant difference between the frequency of marginal bone loss and the amount of marginal bone loss. Conclusion: The extruded natural tooth may cause more frequent complications including bone resorption in the opposing implant.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.3
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• pp.119-131
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• 2009

The world's widely used key exchange protocols are open cryptographic communication protocols, such as TLS/SSL, whereas in the financial field in Korea, key exchange protocols developed by industrial classification group have been used that are based on PKI(Public Key Infrastructure) which is suitable for the financial environments of Korea. However, the key exchange protocols are not only vulnerable to client impersonation attacks and known-key attacks, but also do not provide forward secrecy. Especially, an attacker with the private keys of the financial security server can easily get an old session-key that can decrypt the encrypted messages between the clients and the server. The exposure of the server's private keys by internal management problems, etc, results in a huge problem, such as exposure of a lot of private information and financial information of clients. In this paper, we analyze the weaknesses of the cryptographic communication protocols in use in Korea. We then propose two key exchange protocols which reduce the replacement cost of protocols and are also secure against client impersonation attacks and session-key and private key reveal attacks. The forward secrecy of the second protocol is reduced to the HDH(Hash Diffie-Hellman) problem.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.6
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• pp.147-161
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• 2021

The purpose of this study was to investigate the psychological state and driving safety of drivers driving around the truck platoon driving. Using the driving simulator, the experimental environment was constructed with the situation of changing lanes to the platoon and driving within the platoon. We tried to qualitatively and quantitatively analyze the driver's psychological state and driving safety through simulation driving experiments. As a result, in the case of the older driver group, there were many cases where they judged themselves to be driving safely, even though they were driving dangerously in the actual lane change to the platoon or driving within the platoon. In particular, this group showed that the narrower the distance between vehicles, the greater the misrecognition. The results of this study are expected to be useful in deriving the optimum interval when the interval between platooning of trucks needs to be temporarily extended.

• Journal of Korea Entertainment Industry Association
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• v.14 no.6
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• pp.29-42
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• 2020

This study, we will identify and analyze the current status and trends of successful field trips and field experience learning in Korea to improve the future operation of the center so that the purpose of enhancing the regional economic ripple effect in Gyeongsangbuk-do and regaining its reputation as a school trip mecca and No. 1 location can be found. This study conducted qualitative research through FGI (Focus Group Interview) on accommodation managers, tourism-related stakeholders, tourism officials stakeholders, and tourism professors in order to explore new concepts of field trips and field experience learning in 23 cities and counties in Gyeongsangbuk-do, and ways to develop and promote tour programs based on the importance of experience. Through the FGI (Focus Group Interview) analysis results, problems related to improvement of accommodation, food and beverage, safety and service, cooperation among local tourism officials, enhancement of satisfaction with student group visitors linked to unique tourism resources and promotion, diagnosis and introduction of acceptance posture, and management of local residents, local tourism officials and public officials in Gyeongsangbuk-do needed to present the direction and opportunity of tourism policies in Gyeongsangbuk-do.

• Journal of Navigation and Port Research
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• v.46 no.4
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• pp.338-343
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• 2022

As the revitalization of the global maritime industry continues, the number of foreign ships navigating the maritime territories of maritime neighboring countries has rapidly increased. However, large-scale marine accidents have occurred, caused by the insufficient establishment of a system for management and operation relative to vessels' safety-condition. To address that, the IMO has granted the right to exercise port state control, especially for foreign vessels, to countries with jurisdiction over maritime territories with strengthening regulations and guidelines. In particular, the Republic of Korea, as a member of the TOKYO MOU, is conducting PSC, but as of 2020, the proportion of foreign ships was three times higher than that of national ships that called in domestic ports. However, the inspection rate was low at 9% which has not met the recommended level by the TOKYO MOU. Thus, this study conducted an IPA analysis as well as content analysis, by collecting the practical opinions and views of PSCO through objective questionnaires and written expert interviews, for improving the efficiency and effectiveness of domestic PSC. As a result, it was derived that the importance and performance related to human factors such as life on board, working environment, and response to safety accidents should be improved in to raise the quality of PSC inspection. Additionally, the work environment and performance of PSC in domestic ports for foreign vessels could be improved, if multifaceted support bases are established, for administrative unification of related tests for PSC, recruitment of PSCO, activation of the defection-reporting system, reorganization of the PSC execution group, etc.

• Therapeutic Science for Rehabilitation
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• v.11 no.2
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• pp.77-91
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• 2022

Objective : This study aimed to assess the effects of occupation-based lifestyle intervention programs on older adults in the local community. Methods : Nine community-dwelling older individuals participated in this study using a one-group pre-post design. The occupation-based lifestyle intervention program consisted of 12 group sessions, and one individual session was conducted for seven weeks. Occupational balance, activity occupancy, activity participation, depression, health-related quality of life, and program satisfaction were assessed. Results : The average attendance rate of the nine participants was 10.11 (SD=1.36). Overall occupational balance (p=.012), activity participation status (p=.008), performance (p=.012), and satisfaction with activity participation (p=.008) were increased. Furthermore, the results showed changes in leisure time (p=.008) and rest time (p=.008). Finally, there were some improvements in the overall health-related quality of life (p=.034) and depression scores (p=.012). Conclusions : Occupation-based lifestyle intervention programs positively affected occupational balance, activity occupancy, activity participation, depression, and health-related quality of life in community-dwelling older adults. This research suggests promising benefits and feasibility of the program for community-dwelling older adults.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.1
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• pp.20-32
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• 2022

For this study, 313 pedestrians, including students, from two schools participated in the greening project of the school commuting roads in Seoul. These schools were compared to two without street greenspaces to analyze the effects of the green areas on pedestrian satisfaction and the future direction of creation. As a result of the greenspace satisfaction analysis of schools with greenspace, the items that had the greatest effect on overall satisfaction were 'Width of the sidewalk' (37%), 'Harmony with the surrounding landscape' (24.97%), 'The arrangement of trees, grass, and flowers' (18.30%) and 'Overall management' (10.44%). In other words, the item that satisfies most is securing the appropriate width of the sidewalk where the greenspace is located. It is necessary to re-considered creating greenspaces in existing sidewalk spaces and secure a sidewalk width for pedestrian convenience. As a result of the analysis on the direction of greenspace creation, the respondents who experienced greenspaces through the greenspaces on school commuting routes recognized natural features, such as grass and flowers as more important elements as well as noting that landscape and harmony are important. In addition, respondents interested focusing on functionality recognized the need for greenspaces and highly recognized the importance of arranging natural materials, such as trees, grasses, and flowers. This group also recognized the advantages of functionality and the effectiveness of green spaces. Therefore, it is necessary to expand awareness of the effectiveness of greenspaces through environmental education, publicity, and the provision of information boards. More effort will be needed to apply regional and school characteristics rather than uniform composition to the development of greenspaces.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.167-180
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• 2021

The purpose of this study is to present a framework of the MyData business ecosystem that shows a different pattern from the previous one by the MyData concept and to define the characteristics of actors participating in the ecosystem. Because MyData is an individual exercising sovereignty over his or her data, there is a characteristic that the individual participates as a key actor in the business. In other words, MyData Operators participate in the MyData business ecosystem to help individuals who own MyData, MyData creating business and MyData using business, among them, manage their own data. Therefore, this study conducts a case study of domestic and foreign MyData businesses to revitalize the domestic MyData industry. In particular, the business model of 45 cases of overseas MyData operators was analyzed and classified into 7 types of 4 groups. And through this, the importance of the role of MyData Operator in the MyData industry ecosystem is confirmed and a developmental ecosystem model is proposed.

• Knowledge Management Research
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• v.23 no.2
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• pp.277-299
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• 2022

The massive card transaction data generated in the tourism industry has become an important resource that implies tourist consumption behaviors and patterns. Based on the transaction data, developing a smart service system becomes one of major goals in both tourism businesses and knowledge management system developer communities. However, the lack of rating scores, which is the basis of traditional recommendation techniques, makes it hard for system designers to evaluate a learning process. In addition, other auxiliary factors such as temporal, spatial, and demographic information are needed to increase the performance of a recommendation system; but, gathering those are not easy in the card transaction context. In this paper, we introduce CTDDTR, a novel approach using card transaction data to recommend tourism services. It consists of two main components: i) Temporal preference Embedding (TE) represents tourist groups and services into vectors through Doc2Vec. And ii) Deep tourism Recommendation (DR) integrates the vectors and the auxiliary factors from a tourism RDF (resource description framework) through MLP (multi-layer perceptron) to provide services to tourist groups. In addition, we adopt RFM analysis from the field of knowledge management to generate explicit feedback (i.e., rating scores) used in the DR part. To evaluate CTDDTR, the card transactions data that happened over eight years on Jeju island is used. Experimental results demonstrate that the proposed method is more positive in effectiveness and efficacies.

• Journal of Korean society of Dental Hygiene
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• v.23 no.1
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• pp.25-31
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• 2023

Objectives: This study performed a comparative evaluation of the effects of oil pulling on the periodontal health of smokers. Methods: The experimental (15 subjects) and control (15 subjects) were provided coconut oil and distilled water, respectively. We evaluated the pocket depth (≥4 mm), bleeding on exploration, and Patient Hygiene Performance (PHP) index in both groups following the interventions. Clinical parameters were assessed at baseline, after 4 weeks, and after 8 weeks. Dry mouth and oral health-related quality of life were evaluated at baseline and after 8 weeks. Results: Bleeding on exploring in the control group decreased from 26.17 to 18.33 and from 26.07 to 12.53 in the experimental group (p=0.030), with significant differences in measurement time (p<0.001), and the interaction between group and measurement time (p=0.002). The PHP index in the control group decreased from 24.50 to 16.17 and from 24.00 to 9.83 in the experimental group (p=0.027), with significant differences in measurement time (p<0.001), and the interaction between group and measurement time (p=0.001). Furthermore, the experimental group showed a significant decrease in dry mouth (p<0.001) and a significant increase in oral health-related quality of life (p=0.025). Conclusions: The coconut oil intervention positively affected the periodontal health of smokers.