• The Journal of Advanced Prosthodontics
• /
• 제11권4호
• /
• pp.193-201
• /
• 2019

PURPOSE. The aim of the present study was to evaluate the color changes of an autopolymerizing PMMA resin used for interim fixed restorations, reinforced with $SiO_2$ nanoparticles. MATERIALS AND METHODS. Silica nanoparticles were blended with the PMMA resin powder through high-energy ball milling. Four shades of PMMA resin were used (A3, B3, C3, D3) and total color differences were calculated through the equations ${\Delta}E_{ab}=[({\Delta}L*)^2+({\Delta}a*)^2+({\Delta}b*)^2]^{1/2}$ and ${\Delta}E_{00}=[(\frac{{\Delta}L^{\prime}}{K_LS_L})^2+(\frac{{\Delta}C^{\prime}}{K_CS_C})^2+(\frac{{\Delta}H^{\prime}}{K_HS_H})^2+R_T(\frac{{\Delta}C^{\prime}}{K_CS_C})(\frac{{\Delta}H^{\prime}}{K_HS_H})]^{1/2}$. Statistically significant differences between ${\Delta}E_{ab}$ and the clinically acceptable values of 3.3 and 2.7 and those between ${\Delta}E_{00}$ and the clinically acceptable value of 1.8 were evaluated with one sample t-test (P<.05). Differences among the different shades were assessed through One-Way ANOVA and Bonferroni multiple comparison tests. RESULTS. Significantly lower values were detected for all groups concerning ${\Delta}E_{ab}$ compared to the intraorally clinical acceptable values of 3.3 and 2.7. Significantly lower mean values were detected for groups B3, C3, and D3, concerning ${\Delta}E_{00}$ compared to the intraorally clinical acceptant value of 1.8. Color pigments in red-brown (A3) and red-grey (D3) shades affect the total color change to a greater extent after the reinforcement with $SiO_2$ nanoparticles compared to the red-yellow (B3) shade. CONCLUSION. Within the limitations of this in vitro study, it can be suggested that reinforcing PMMA with $SiO_2$ nanoparticles at 0.25 wt% slightly affects the optical properties of the PMMA resin without being clinically perceivable.

• 한국재난정보학회 논문집
• /
• 제17권3호
• /
• pp.556-567
• /
• 2021

연구목적: 본 연구에서는 무인이동체를 활용한 철도교량의 외관조사 점검을 보다 효율적이고 신뢰성 있게 점검을 위하여 무인이동체를 통해 촬영된 이미지를 바탕으로 다양한 방식의 딥러닝 기반 자동 손상 분석기술을 검토하였다. 연구방법: 취득된 이미지를 바탕으로 손상항목을 정의하고 학습데이터로 추출하여 딥러닝 분석 모델을 생성하였다. 그리고 철도교량의 외관 손상 중 균열, 콘크리트 박리·박락, 누수, 철근노출에 대한 손상 이미지를 학습한 모델을 적용하여 자동 손상 분석 결과로 테스트하였다. 연구결과: 분석 결과 평균 95%이상 검측 재현율을 도출하는 분석 기법을 검토할 수 있었다. 이와 같은 분석 기술은 기존 육안점검 결과 대비 보다 객관적이고 정밀한 손상 검측이 가능하다. 결론: 본 연구를 통해 개발된 기술을 통해 철도 유지관리 분야에서 무인이동체를 활용한 정기점검 시 자동손상분석을 통한 객관적인 결과도출과 기존 대비 소요시간, 비용저감이 가능할 것으로 기대된다.

• Geomechanics and Engineering
• /
• 제24권2호
• /
• pp.129-141
• /
• 2021

The vacuum preloading method has been used in many countries for soil improvement and land reclamation. However, the treatment time is long and the improvement effect is poor for the straight-line vacuum preloading method. To alleviate such problems, a novel combined air booster and straight-line vacuum preloading method for shallow ground treatment is proposed in this study. Two types of traditional vacuum preloading and combined air booster and straight-line vacuum preloading tests were conducted and monitored in the field. In both tests, the depth of prefabricated vertical drains (PVDs) is 4.5m, the distance between PVDs is 0.8m, and the vacuum preloading time is 60 days. The prominent difference between the two methods is when the preloading time is 45 days, the injection pressure of 250 kPa is adopted for combined air booster and straight-line vacuum preloading test to inject air into the ground. Based on the monitoring data, this paper systematically studied the mechanical parameters, hydraulic conductivity, pore water pressure, settlement and subsoil bearing capacity, as determined by the vane shear strength, to demonstrate that the air-pressurizing system can improve the consolidation. The consolidation time decreased by 15 days, the pore water pressure decreased to 60.49%, and the settlement and vane shear strengths increased by 45.31% and 6.29%, respectively, at the surface. These results demonstrate the validity of the combined air booster and straight-line vacuum preloading method. Compared with the traditional vacuum preloading, the combined air booster and straight-line vacuum preloading method has better reinforcement effect. In addition, an estimation method for evaluating the average degree of consolidation and an empirical formula for evaluating the subsoil bearing capacity are proposed to assist in engineering decision making.

• 대한예방한의학회지
• /
• 제24권3호
• /
• pp.57-67
• /
• 2020

Background : The Life cycle Health Promotion Programs using Traditional Korean Medicine (the Life cycle HaPPs-TKM) are the on-going 3rd stage projects that have centered on the development and dissemination of the standard life cycle HaPPs-TKM in the local community. The purpose of the study was to introduce the development background of the standard life cycle HaPPs-TKM and to suggest its activation plan. Methods : Academic and government research reports on the life cycle HaPPs-TKM were analyzed to introduce the development process, development backgrounds and the details of KM-HPP for each life cycle, such as infants and toddlers, adolescents, pregnant women, adults and the elderly. Results : We reviewed the development process of the standard life cycle HaPP-TKM consisted of a series of diagnosis on community members' health problems, establishment of project purpose, research on the involvement of KM intervention in a project, and final development of the project model. And we rediscovered that in the development backgrounds of KM-HPP, there were beneficial goals to manage and promote public health conditions for each life cycle. Conclusion : To activate life cycle HaPPs-TKM, we would recommend that activation plan should include six factors through systematic analysis of research reports. These factors consist of diversified goals for each life-cycle, competency reinforcement of local project manager, diversified Korean Medicinal modalities to enhance Sasang Constitution and Qigong, development of standard Outcome Index, periodical holding of performance contest, and improved guidance of government and associated entities through whole process of HaPP-TKM.

• 정보보호학회논문지
• /
• 제16권6호
• /
• pp.135-149
• /
• 2006

무선 Ad hoc 네트워크는 통신 채널의 취약성, 노드의 보안 취약점, 기반 구조의 부재, 동적인 위상 변화 등의 특성으로 인해 보안 메커니즘 설계 및 구현이 기존 유선 네트워크에 비해 어려운 것으로 인식되고 있다. 기존의 연구들이 유선 네트워크의 보안을 무선 Ad hoc 네트워크로 적용하는데 많은 노력을 기울여 왔으나, 무선 Ad hoc 네트워크의 본질적인 문제로 인하여 효과적인 성과를 거두지 못하고 있다 본 논문은 무선 Ad hoc 네트워크의 보안 분야 중에서 하나 또는 둘 이상의 협업된 위장노드들의 대량의 위장 패킷 공격으로 인해 네트워크 자체의 생존성 및 가용성에 새로운 문제가 있음을 제기하고 그 결과를 증명한다. 또한 무선 Ad hoc 네트워크의 생존성 및 성능 향상을 위한 접근 방법으로 기존 방식의 기준을 탈피하여 무선 Ad hoc 네트워크의 특성을 반영하는 생존성 강화를 위하여 효율적인 위장 공격 방지 메커니즘을 제안한다.

• Archives of Plastic Surgery
• /
• 제48권1호
• /
• pp.3-9
• /
• 2021

Background For an attractive and natural tip contour in Asian rhinoplasty, insertion of a nasal implant and reinforcement of the cartilaginous framework are essential. However, scar contracture, which often results from augmentation with implant insertion and inadequate soft tissue coverage of the framework, is one of the most common causes of alar retraction. This study reports a novel method of redraping soft tissue along the alar rim to prevent alar retraction in Asians. Methods Twenty young Asian men who underwent primary rhinoplasty with septoplasty were retrospectively reviewed. After the usual rhinoplasty procedures, alar rim redraping was conducted for the soft tissue along the transcolumellar and bilateral infracartilaginous incisions. The longest axis of the nostril (a) and the height of the nostril from that axis (b) were measured in anterior-posterior and lateral views. The preoperative and postoperative ratios (b/a) were analyzed using the paired t-test. Results All 20 patients showed natural contours of the nasal tip, nostrils, and alae after a mean follow-up of 53.6 weeks (range, 52-60 weeks). The ratio of the nostril axes significantly decreased postoperatively in all patients except one, by an average of 11.08%±6.52% in the anterior-posterior view and 17.74%±8.49% in the lateral view (P<0.01). There were no complications, including asymmetry, contracture, subdermal plexus injury, flap congestion, or infection. Conclusions A quantitative analysis of alar retraction by evaluating the ratio of nostril axes showed that alar rim redraping is a simple and effective adjuvant technique for preventing alar retraction in rhinoplasty for young Asian men.

• Structural Engineering and Mechanics
• /
• 제77권4호
• /
• pp.441-461
• /
• 2021

Reinforced concrete (RC) columns are crucial in building structures and they are of higher vulnerability to terrorist threat than any other structural elements. Thus it is of great interest and necessity to achieve a comprehensive understanding of the possible responses of RC columns when exposed to high intensive blast loads. The primary objective of this study is to derive analytical formulas to assess vulnerability of RC columns using an advanced numerical modelling approach. This investigation is necessary as the effect of blast loads would be minimal to the RC structure if the explosive charge is located at the safe standoff distance from the main columns in the building and therefore minimizes the chance of disastrous collapse of the RC columns. In the current research, finite element model is developed for RC columns using LS-DYNA program that includes a comprehensive discussion of the material models, element formulation, boundary condition and loading methods. Numerical model is validated to aid in the study of RC column testing against the explosion field test results. Residual capacity of RC column is selected as damage criteria. Intensive investigations using Arbitrary Lagrangian Eulerian (ALE) methodology are then implemented to evaluate the influence of scaled distance, column dimension, concrete and steel reinforcement properties and axial load index on the vulnerability of RC columns. The generated empirical formulae can be used by the designers to predict a damage degree of new column design when consider explosive loads. With an extensive knowledge on the vulnerability assessment of RC structures under blast explosion, advancement to the convention design of structural elements can be achieved to improve the column survivability, while reducing the lethality of explosive attack and in turn providing a safer environment for the public.

• 임상간호연구
• /
• 제27권2호
• /
• pp.149-164
• /
• 2021

Purpose: The purpose of this study was to develop a Korean Nurse Residency Program (KNRP) in order to facilitate new nurses' transition to clinical practice working at tertiary hospitals in Korea. Methods: The KNRP was developed through a literature review, investigation of NRP cases in United States, two rounds of expert consultation, and appropriateness survey. For appropriateness survey of the program, a questionnaire with 118 items and 14 subcategories including overview and operation of KNRP, education programs, staffing criteria for new nurses' education, preceptor supporting strategies, evaluation standards for new nurse's education, infrastructure, and KNRP benefits was used. Data were collected from 369 nurses including nurse educators, nurse managers, preceptors, and new nurses working at 43 tertiary hospitals in Korea from February 16, 2021 to March 22, 2021. Data were analyzed with descriptive statistics. Results: Appropriateness score of KNRP was 3.42±0.31 (out of 4) and those of 14 subcategories ranged from 3.18±0.47 to 3.58±0.46. The final version of the KNRP postulated is a one-year program, which is composed of off-job training and on-site training including preceptorship over 3 months, and competency reinforcement and adaptation supporting programs. Conclusion: The application of the one-year KNRP will facilitate new graduate nurses' transition to clinical practice. In order for effective application of the KNRP, cooperative efforts of the government, professional associations, and hospitals are needed.

• 지역사회간호학회지
• /
• 제32권4호
• /
• pp.518-528
• /
• 2021

Purpose: This study was conducted to explore the healthcare experience of residents participating in the Community-Based Hypertension and Diabetes Registry Program. Methods: This study used qualitative content analysis. Data were collected from in depth interviews of fifteen participants, who either participated in the program hosted by the Training Center for Hypertension and Diabetes for more than two years or participated in an intensive one-on-one education program. Results: The results showed that the core theme in healthcare of participants was 'Proactive healthcare with attention and systematic guidance of experts'. The positive reinforcement of staffs and the improvement of self-efficacy through effective close management were found to be positive influencing factors of participation. The theme consisted of the following categories: 'Participation in the program with positive expectations on healthcare', 'Interest in body and health', 'Vitality in life', 'Confidence in dealing with disease', 'Thankfulness for close care and attention', and 'Desire for continuous care'. Conclusion: When establishing policies on managing chronic diseases, a strategy that reflects the results of the study is required. It is necessary to build up emotional relationship among stakeholders, and expand opportunities for close healthcare such as one-on-one customized training, and mutual cooperation with various organizations in the local community.

• 한국융합학회논문지
• /
• 제13권4호
• /
• pp.635-641
• /
• 2022

사회적경제조직은 그동안 다양한 유형과 분야에서 양적인 성장을 가져왔으나 주로 정부가 주도하는 형태로 추진되어왔고 아직 선진국과 비교해 볼 때 제도적 정비나 지원체계 및 지원방식 등 질적으로 개선해야 할 여지가 많다. 본 연구에서는 선행연구를 통해 나타난 사회적경제조직의 문제점, 사회적경제조직의 현황과 실태분석, 정책전달 체계, 사회적경제조직 발전의 장애요인, 활성화의 문제점 등을 검토하였다. 이를 통해 미래 사회적경제조직의 활성화를 위한 정책 방향과 추진과제를 제시하여 보았다. 그 결과 사회적경제조직의 활성화를 위한 정책방향은 민간·지자체 주도, 진출분야의 확대, 성장생태계 조성을 위한 맞춤형 지원, 다양한 연계협력이 필요하고 추진 과제로는 제도개선을 위한 법령제정 및 개정, 사회적경제조직의 역량개발과 교육, 다양한 연계협력체제 강화, 투자생태계 조성, 공동판로개척 등이 필요하다.