• Title/Summary/Keyword: problem analysis

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COMPARATIVE STUDY ON THE FRACTURE STRENGTH OF METAL-CERAMIC VERSUS COMPOSITE RESIN-VENEERED METAL CROWNS IN CEMENT-RETAINED IMPLANT-SUPPORTED CROWNS UNDER VERTICAL COMPRESSIVE LOAD

  • Pae, Ahran;Jeon, Kyung-A;Kim, Myung-Rae;Kim, Sung-Hun
    • The Journal of Korean Academy of Prosthodontics
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    • v.45 no.3
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    • pp.295-302
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    • 2007
  • Statement of problem. Fracture of the tooth-colored superstructure material is one of the main prosthetic complications in implant-supported prostheses. Purpose. The purpose of this in vitro study was to compare the fracture strength between the cement-retained implant-supported metal-ceramic crowns and the indirect composite resinveneered metal crowns under the vertical compressive load. Material and methods. Standard implants of external type (AVANA IFR 415 Pre-mount; Osstem Co., Busan, Korea) were embedded in stainless steel blocks perpendicular to their long axis. Customized abutments were fabricated using plastic UCLA abutments (Esthetic plastic cylinder; Osstem Co., Busan, Korea). Thirty standardized copings were cast with non-precious metal (Rexillium III, Pentron, Walling ford, Conn., USA). Copings were divided into two groups of 15 specimens each (n = 15). For Group I specimens, metal-ceramic crowns were fabricated. For Group II specimens, composite resin-veneered (Sinfony, 3M-ESPE, St. Paul, MN, USA) metal crowns (Sinfony-veneered crowns) were fabricated according to manufacturer's instructions. All crowns were temporary cemented and vertically loaded with an Instron universal testing machine (Instron 3366, Instron Corp., Norwood, MA, USA). The maximum load value (N) at the moment of complete failure was recorded and all data were statistically analyzed by independent sample t-test at the significance level of 0.05. The modes of failure were also investigated with visual analysis. Results. The fracture strength of Sinfony-veneered crowns ($2292.7{\pm}576.0N$) was significantly greater than that of metal-ceramic crowns ($1150.6{\pm}268.2N$) (P < 0.05). With regard to the failure mode, Sinfony-veneered crowns exhibited adhesive failure, while metal-ceramic crowns tended to fracture in a manner that resulted in combined failure. Conclusion. Sinfony-veneered crowns demonstrated a significantly higher fracture strength than that of metal-ceramic crowns in cement-retained implant-supported prostheses.

The Effect of the Perception of Air Pollution on Life Satisfaction and the Moderating of Said Effect with Green Spaces (대기오염 인식이 삶의 만족도에 미치는 영향과 녹지환경 만족도의 조절효과)

  • Lee, Sungeun
    • Journal of Korean Society of Forest Science
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    • v.108 no.4
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    • pp.639-644
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    • 2019
  • The purpose of this study was to examine the moderating effect of green space satisfaction on the relationship between the perception of air pollution and life satisfaction. To achieve this, the current study employed data from the 2018 Social Survey, and a sample of 37,461 participants was analyzed using moderated multiple regression analysis. Results showed that while greater satisfaction with green spaces improved life satisfaction, a more negative perception of air pollution within the community reduced life satisfaction. It was also found that green space satisfaction moderated the relationship between the perception of air pollution and life satisfaction. In other words, greater satisfaction with green spaces buffered the effect of a negative perception of air pollution on life satisfaction. The results of this study suggest that a green environment should be considered an important resource for preventing reduced life satisfaction, and illustrate that there is a need for developing various strategies for the expansion and improvement of green spaces within communities.

A typology of relative importance to the work and family life of married men (기혼 남성의 삶에서 일과 가정생활이 차지하는 비중에 따른 유형 및 유형별 특성)

  • Lee, Sujin;Koo, Hye-Ryoung
    • Journal of Family Resource Management and Policy Review
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    • v.18 no.4
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    • pp.135-151
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    • 2014
  • This study focused on issues of relative importance to the work and family life of married men. The work was carried out to determine, when men are in any category, how to increase their satisfaction with their work and family life. Data from 896 married men with their youngest children under 18 years of age was collected and analyzed. Cluster analysis was performed to classify the categories depending on the relative importance of work as compared to family life. I obtained four types relating to the relative importance of work compared to family life. The results are as follows. First, the score of subjective balance which was perceived by the men was slightly higher than the normal range, at 3.27 points. Second, work-family negative spillover is bigger than family-work negative spillover. On the other hand, family-work positive spillover is bigger than work-family positive spillover. Third, in the category in which the difference is largest between the relative importance of work and family life, the men crave the value of nonwork. It seems that in order to bring a particular gravity to work, there is a possibility that the areas outside of work will be suppressed. Also, in this category, both the satisfaction of family life and job satisfaction were low; this will be a point to consider when discussing the problem of the balance of work and family.

Recognition and Preference of Native Local Foods by University Students in Chonbuk Area (전북지역 향토음식에 대한 대학생의 인지도 및 기호도에 관한 연구)

  • Yang Hyang-Sook;Rho Jeong-Ok
    • Journal of the Korean Home Economics Association
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    • v.43 no.11 s.213
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    • pp.49-58
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    • 2005
  • This study investigated the recognition and preference of native local foods in area by students living in Jeonju. Statistical data analysis was completed using the SPSS 10.0 program. The recognition of native local foods was generally poor: Among 56 kinds of native foods only Jeonjubibimbab, Jeonjukongnamulkukbob and Sunsoonsabockbunjasul were highly recognized, whereas the other native foods (such as Pungchyunjangaguvi. Namwonchuatang, Jeonjukongnamulkukbob, Sunsoonsabockbunjasul, Pungchyunjangaguyi, Namwonchuatang, Minmulgokiajuk etc.) were very poorly recognized by students. About $48.6\%$ of the students acquired the knowledge on cooking the native local foods from their mother or grandmother. About half of the students had eaten the native local foods in a restaurant, but not at home. The reasons to eat the native local foods were 'curiosity', 'favorite' and 'consider about health and nutrition'. The most common frequency of consumption of the native foods by the students was once a month($24.0\%$). However $74.9\%$ of the students did not eat local foods because they did not have a opportunity to eat them. About $49.1\%$ of the students responded that the 'unknown cooking method' was an important problem for the further development for native local foods. Most of the students($97.3\%$) responded, somewhat hypocritically, that native local foods were a very important part of our culture, so they must be maintained. In conclusion, the further development of native local foods was dependent on the cooperation with different institutions (e.g. marketing of local mass media, local events, family education).

A Study on the Determinants of Married-Working Women's Childbirth Intention (기혼 직장여성의 출산의도 결정요인에 관한 연구)

  • Jang, Hanna;Lee, Myungsuk
    • Human Ecology Research
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    • v.51 no.4
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    • pp.425-438
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    • 2013
  • Postponing childbirth is becoming increasingly common and consequently serious social problem in Korea, among married-working women. It is relatively unknown which factors determine married-working women's childbirth intention. This study investigated the effects of demographical factors, labor market factors and social support factors on married-working women's childbirth intention. Data from a national survey of married-working women (Korean longitudinal survey of women and families) are used in this study. The findings are as follows. First, logistic regression analyses that married-working women's childbirth intention could be predicted by 1) personal characteristic factors such as age (p <.000), education level (p<.029), parenthood (p<.000) monthly pay (p<.01); 2) husband support factors, such as satisfaction with division of household labor (p<.009), time with family (p<.049) influence of family life on work (p<.083); and 3) institutional support factors such as regular position (p<.015), regression analysis showed similar results. Personal characteristic factors and husband support factors had statistically significant effects on the number of future children. Personal value factors such as traditional family support (p<.05) proved to be the best predictor of the number of future children. Institutional support factors, on the other hand, did not have statistically significant effect on the number of future children. In a nutshell, personal characteristics and husband support proved to be the most important determinant of married-working women's childbirth intention. The findings suggest that family friendly policy and flexible labor market policy will impact married-working women's childbirth intention.

A Study on p-y Curves for Nearshore Seabed of Jeju Island (제주 연근해 해저암반의 p-y 곡선 모델에 관한 연구)

  • Jang, Young-Eun;Lee, Joonyong;Cho, Samdeok;Yoo, Dong-Woo;Choi, Changho
    • Journal of the Korean GEO-environmental Society
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    • v.13 no.6
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    • pp.73-81
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    • 2012
  • Safety issue for offshore wind-turbine foundation becomes a crucial factor as offshore wind turbines have been scaled up. Correspondingly, there is a demand to understand the effect of soil-structure interaction on to system behavior in geotechnical engineering point of view. The p-y curve method researched in past few decades is one of the most appropriate methodology to analyze the problem. In this study, recently proposed p-y curve models for various rocks are calibrated to analyze the engineering characteristics of seabed of Jeju Island where it is known to be most suitable area for offshore wind energy farm. Step by step calibration process for p-y models is presented. Analysis results show that subgrade reaction generally increases as closer to seabed. It is also shown that the behavioral characteristics of foundation reflect well rock properties in terms of resultant moment, shear force, etc.

A Study on the Processes of Elaborating Hypotheses in Abductive Inquiry of Preservice Elementary School Teachers (예비 초등 교사들의 귀추적 탐구 활동에서 가설의 정교화 과정에 관한 연구)

  • Oh, Phil-Seok;Oh, Sung-Jin
    • Journal of The Korean Association For Science Education
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    • v.31 no.1
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    • pp.128-142
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    • 2011
  • The goal of this study was to investigate how hypotheses were elaborated after their initial appearances in the context of scientific problem solving. Data were collected from a class in which preservice elementary school teachers in groups carried out abductive inquiry of earth science. The analysis revealed two major processes of hypothesis elaboration: theory-driven and evidence-driven. The theory-driven process was in turn distinguished into two kinds of subprocesses: one is in pursuit of internal coherence and the other external coherence. The evidencedriven elaboration also had two subprocesses, which were triggered by direct evidence and indirect or analogical evidence, respectively. In addition, hypotheses were more often than not modified by a wrong theory or evidence whether it was driven by a theory or evidence. Implications for science education and related research were discussed.

Simplified Analytical Model for Flexural Response of Fiber Reinforced Plastic Decks (FRP 바닥판의 휨 해석모델 개발)

  • Kim, Young-Bin;Lee, Jae-Hong
    • Journal of Korean Association for Spatial Structures
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    • v.5 no.3 s.17
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    • pp.65-74
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    • 2005
  • An analytical model was developed to investigate the flexural behavior of a pultruded fiber-reinforced plastic deck of rectangular unit module. The model is based on first-order shea. deformable plate theory (FSDT), and capable of predicting deflection of the deck of arbitrary laminate stacking sequences. To formulate tile problem, two-dimensional plate finite element method is employed. Numerical results are obtained for FRP decks under uniformly-distributed loading, addressing the effects of fiber angle and span-to-height ratio. It is found that the present analytical model is accurate and efficient for solving flexural behavior of FRP decks. Also, as the height of FRP deck plate is higher, the necessity of higher order Shear deformable plate theory(HSDT) is announced, not the FSDT in the plate analysis theory.

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Microvibration Control of High Technology Facilities Subjected to Train-induced Excitation using Smart Base Isolation (열차진동하중을 받는 첨단시설물의 스마트 면진시스템을 이용한 미진동제어)

  • Kim, Hyun-Su;Kang, Joo-Won;Kim, Young-Sik
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.2
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    • pp.99-108
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    • 2012
  • Microvibration problem of high-technology facilities, such as semi-conductor plants and TFT-LCD plants, has been considered as important factors that affects the performance of products and thus it is regarded as important in facilities with high precision equipments. In this paper, various base isolation control systems are used to investigate their microvibration control performance. To this end, train-induced ground acceleration is used for time history analysis and three-story example building structure is employed. Microvibration control performance of passive and smart base isolation systems have been investigated in this study. Based on numerical simulation results, it has been verified that smart base isolation system can control microvibration of a high-technology facility subjected to train-induced excitation.

Analysis of Socioeconomic Costs of Child Missing (아동실종으로 인한 사회경제적 비용 분석)

  • Chung, Ick-Joong;Kim, Sung-Chun;Song, Jae-Seok
    • Korean Journal of Social Welfare
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    • v.61 no.2
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    • pp.371-389
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    • 2009
  • This study estimates the socioeconomic costs of missing children in Korea. The costs were classified as direct costs and indirect costs. The direct costs consisted of direct costs for searching for missing child such as making posters, transportation, and medical costs. The indirect costs were computed by the opportunity costs caused by child missing. The total costs that could be attributable to missing child were estimated to be about 570 million won per long-term missing child. This provides strong evidence that prevention of child missing is the most important and quick recovery after child is missing is the second most important. Missing child incurs substantial socioeconomic costs to the Korean society. Therefore, this study provides strong need for more interest from people who are indifferent to missing child issues and strong support for more government interventions to solve missing child problem in Korea. Further studies are needed to calculate socioeconomic costs of child missing more exactly.

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