• The Journal of Korean Academy of Prosthodontics
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• v.61 no.2
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• pp.101-112
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• 2023

Purpose. This retrospective study was to investigate the survival and complication rates of posterior single implant according to the implant diameters, lengths and position. Materials and methods. Patients who had been restored single implant prosthesis in the posterior area by the three prosthodontists in the department of prosthodontics, Daejeon dental hospital of Wonkwang university, in the period from February 2014 to May 2018 were selected for the study. A total of 505 patients with 697 implants were observed. The survival and complications of implants were investigated using electronic medical records and radiographs. Fixture diameters, lengths, position, patient's sex and age were assessed as possible factor affecting the survival and complications of implants. Results. 3-year cumulative survival rates of posterior single implants were 98.5% and 5-year cumulative survival rates were 94.4%. 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm (97.0%) than implants with diameter ≤ 4.0 mm (89.5%), and in females (98.8%) than males (92.4%). There were statistically significant differences (P < .05). The mechanical complication rate was 20.1% and the biological complication rate was 4.7%. Complications occurred in order of abutment screw loosening (7.5%), decementation (6.3%), proximal contact loss (3.7%) and so on. Abutment screw loosening occurred more frequently in the lower molar region (10.5%), in males (9.5%) than females (5.1%), and in patients aged < 65 years (9.4%) than patients aged ≥ 65 years (5.1%). There were statistically significant differences (P < .05). Conclusion. The 5-year cumulative survival rates were higher in implants with diameter > 4.0 mm than implants with diameter ≤ 4.0 mm and in females than males. Abutment screw loosening which was the most commonly occurring complication occurred more frequently in the lower molar region, in males than females, and in patients aged < 65 years than patients aged ≥ 65 years. There were statistically significant differences.

• Journal of agricultural medicine and community health
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• v.48 no.4
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• pp.239-250
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• 2023

Objective: This study was a preliminary study for the prevention programs for farmers' occupational diseases. It selected the priorities recognized by farmers, such as occupational diseases, and also identifies the effectiveness and feasibility of prevention programs among diseases recognized by farmers. Therefore, we plan to use it as basis data for future farmer safety and health programs. Method: The subjects of the study were farmers living in the region, selected through a snowball recruitment method, and a total of 671 people were targeted. The priority selection method was the Basic Priority Rating System (BPRS) method, and among the occupational diseases, programs to prevent musculoskeletal diseases, cardiovascular and respiratory diseases, and pesticide poisoning were surveyed on the effectiveness and feasibility of farmers. Results: Among occupational diseases, the highest priority was musculo-skeletal disease, followed by respiratory disease and pesticide poisoning. Among the programs for musculoskeletal disease, 'use of agricultural work convenience equipment and auxiliary tools' had the highest perceived effectiveness and feasibility. Among the five programs for pesticide poisoning, 'equipment of protective equipment such as pesticide protective clothing/glove' had the highest effectiveness at 67.4%, and 'compliance with pesticide use instructions' had the highest level of feasibility at 64.3%. Among the four programs to prevent respiratory diseases, 'wearing a dust mask or gas mask' was the highest at 65.5% in terms of both effectiveness and feasibility. Conclusion: When carrying out safety and health programs for farmers, the priorities recognized by farmers should be taken into consideration, and the program contents should also be developed taking into account the size of effect and feasibility recognized by farmers.

• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.187-194
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• 2023

Purpose: A mismatched size in the post and post space is a common problem during post-fixation. Since this discordance affects the bonding strength of the fiber-reinforced composite resin post (FRC Post), a corresponding luting agent is required. The aim of this study was to evaluate the bonding strength of the FRC post according to the fitness of the fiber post and the type of luting agent. Materials and Methods: Thirty mandibular premolar were endodontic-treated and assigned to two groups according to their prepared post space: Fitting (F) and Mismatching (M). These groups were further classified into three subgroups according to their luting agent: RelyX Unicem (ReX), Luxacore dual (Lux), and Duolink (Duo). A push-out test was performed to measure the push-out bond strengths. The fractured surfaces of each cross-section were then examined, and the fracture modes were classified. Results: In the ReX and Duo subgroups, the F group had a higher mean bond strength; however, the Lux subgroup had no significant difference between the F and M groups. In the analysis of the failure modes, the ReX subgroup had only adhesive failures between the cement and dentin. Conclusion: The result of this study showed that the bond strength of an FRC post was influenced by the type of luting agent and the mismatch between the diameter of the prepared post space and that of the post.

• Proceedings of the Korean Statistical Society Conference
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• 2004.11a
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• pp.259-263
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• 2004

통계학의 여러 개념들을 효과적으로 가르치기 위한 다양한 연구들이 진행되고 적용되고 있다. 그러나 기초통계학 교육에서 교수자와 학습자 모두 교수와 학습의 어려움을 끊임없이 제기하고 있다. 또한 기존의 교수학습 방법들을 현실에 적용하기에는 시간과 교구재 등 여러 가지 어려움이 있어서 실제 적용되지 못하고 있는 것이 현실이다. 본 연구에서는 기존의 연구들에서 주장하고 입증된 교수학습 방법들을 교실 현장에서 쉽게 적용할 수 있도록 하는 통계 교수학습 모형을 제시하고자 한다. 이를 위해 문제위주 학습과 협동학습 등을 통해 학습자의 참여를 높여 학습효과를 증대할 수 있는 구성 주의적 학습활동을 네트워크와 웹을 기반으로 수행하는 교수학습 모형을 제안한다

• Proceedings of the KOR-BRONCHOESO Conference
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• 1979.05a
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• pp.4.2-4
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• 1979

Since Metz had employed the impedance audiometry in 1946, scholars have carried out many investigation. Brook, Jeger, Cooper reported and evaluated the clinical studies of impedance audiometry and its screening test. Recently, in Korea, a studies of impedance audiometry have been reported. We analysed 100 children aged between 7-16 years old who visited OPD of E.N.T. department with the complaints of the nasal obstruction and hard of hearing from Nov. 77-Feb. 79. Through the use of otoscope and impedance audiometry, we evaluated the types of tympanogram, static compliance and the acoustic reflex. This paper is dealing with the statistical study of impedance audiometric result and its literature.

• Communications of Mathematical Education
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• v.13 no.1
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• pp.1-18
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• 2002

거리 수학이 학교 수학에 통합되어 수학 교실에서 지도되고 있는 하나의 예로 어림을 들 수 있다. 학교수학에서 지도되는 지필 알고리즘과는 달리 어림은 대략적인 값을 구하며, 주로 암산으로 수행된다. 그러나 어림은 학생들의 수학 학습과 일상생활에서 많은 유용성을 가지고 있음에도 불구하고 지금까지 수학 교육과정에서는 간과되었으나 최근 들어 강조되고 있는 영역이다. 따라서 본 연구에서는 학교 수학에서 지도되는 어림을 고찰함으로써 거리 수학을 학교 수학에 통합하려는 수학과 교수-학습에 시사점을 제공하는 것을 목적으로 한다. 연구의 목적을 실현하기 위해 거리 수학과 학교 수학을 규명하고, 거리 수학과 학교 수학을 연결하는 다리로서의 어림에 대해서 고찰하였다. 다음으로 초등학교 6학년 학생들을 대상으로 어림 능력 검사를 실시함으로써 초등학교 교육을 통해서 학생들에게 길러지는 어림 능력을 분석하였다.

• Proceedings of the Korea Contents Association Conference
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• 2012.05a
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• pp.91-92
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• 2012

본 연구는 기초생활수급자 외에 복지 사각지대에 있는 차상위 계층 대상의 경제와 교육생활실태 그리고 복지욕구를 파악하여 사회복지전달체계의 복지안전망을 구축함으로써 기초생활수급자로 전락되지 않도록 하기 위한 연구이다. 이를 위해 경기도 고양시 거주민 중 차상위 계층 주민 408명을 대상으로 조사한 결과, 경제부문 중 전세금과 생활비 지출 부담으로 경제적 지원, 교육부문 중 양육비와 교육비 지원, 복지욕구 부문 중 방과후 교실과 무료 및 치과진료, 명절지원, 취업연계 및 교육서비스, 후원금 지원 등에 대한 욕구가 높았다. 따라서 차상위 계층에 대한 지역사회보호체계 확충과 서비스 대상자의 역량강화 모색, 가족구성별 맞춤형 프로그램 개발 및 운영 확대, 빈곤탈출을 위한 지원서비스 확대가 이루어질 수 있도록 사회변화에 맞는 사회복지정책 방향이 모색되어야 할 것이다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.484-486
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• 2022

This study compares these two platforms with Gedertown and Zepeto, which have the largest number of users among metaverse that have grown rapidly due to various factors such as COVID-19 pandemic. It focuses on the differences between avatars, usage fees, class rooms, and communication methods. Accordingly, the difference between 2D and 3D of the metaverse platform and the difference in camera use can be seen.

• Journal of The Korean Association of Information Education
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• v.15 no.1
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• pp.51-58
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• 2011

Recently, STEM education and improvement in creativity took a lot of attention in local and foreign educational programs, and the robot education is regarded as one of the answers which can achieve the objectives. The robot education is quite active locally in various ways including robot classes for after school program in elementary schools, a number of robot competitions, and education for the gifted. Under these circumstances, the qualification test for robot technology is developed to provide a standard for evaluating professional knowledge on robotics and is currently under consideration to be one of the government-approved qualification tests. However, compared to the robot classes for after school program, this test is not well recognized by most teachers in elementary and middle schools. This paper addresses and analyzes the current status of the test, in particular, backgrounds, qualification standards, organizing committee, intention of presenting questions, examples of problems used in the test, and demands raised by applicants, etc. Base on the analysis, some suggestions are made to establish a solid standard for evaluating robot technologies. It is suggested that the level of difficulty and contents covered should be properly adjusted considering the level of applicants. In addition, it is essential to provide well organized supplementary material for students and wide range of contents on robot technology. Finally, some efforts including cooperating with the robot classes for after school program should be made to invigorate the test.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.188-194
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• 2005

To assess microbiological indoor air quality in schools, concentrations of viable airborne microorganisms were monitored at classrooms and corridors of 3 middle or high schools in Ulsan. Airborne microorganisms were sampled at various situations during a semester (class-hour, lunchtime, after school) and during a vacation with an impaction-type air sampler. During the semester, the number of bacteria was the highest at lunchtime in corridor with an average of $1,111\;MPN/m^{3}$ and lowest at class-hour in corridor with an average of $132\;MPN/m^{3}$. During the vacation, the bacterial concentrations at classrooms and corridors were only $5{\%}$ and $27{\%}$ of the values during class-hours of the semester, respectively. Among the colonies tested, $60{\%}$ were identified as relatively harmless Micrococcus species and $12{\%}$ were Staphylococcus species. During the semester, the average values of fungal concentrations at each situation ranged from 105 to $213\;MPN/m^{3}$, and the values during the vacation were $32\;MPN/m^{3}$ at classrooms and $83\;MPN/m^{3}$ in corridors. Fungal genera such as Cladosporium, Penicillium, and Aspergillus were identified from the colonies. The obtained data can be considered as a step to set a guideline for bioaerosols in indoor environment of schools.