• The Journal of Advanced Prosthodontics
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• 제10권5호
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• pp.347-353
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• 2018

PURPOSE. The purpose of this study was to evaluate the marginal discrepancy of heat-pressed ceramic veneers manufactured using a CAD/CAM system. MATERIALS AND METHODS. The ceramic veneers for the abutment of a maxillary left central incisor were designed using a CAD/CAM software program. Ten veneers using a microstereolithography apparatus (AM group), ten veneers using a five-axis milling machine (SM group), and ten veneers using a traditional free-hand wax technique (TW group) were prepared according to the respective manufacturing method. The ceramic veneers were also fabricated using a heat-press technique, and a silicone replica was used to measure their marginal discrepancy. The marginal discrepancies were measured using a digital microscope (${\times}160$ magnification). The data were analyzed using a nonparametric Kruskal-Wallis H test. Finally, post-hoc comparisons were conducted using Bonferroni-corrected Mann-Whitney U tests (${\alpha}=.05$). RESULTS. The $mean{\pm}SD$ of the total marginal discrepancy was $99.68{\pm}28.01{\mu}m$ for the AM group, $76.60{\pm}28.76{\mu}m$ for the SM group, and $83.08{\pm}39.74{\mu}m$ for the TW group. There were significant differences in the total marginal discrepancies of the ceramic veneers (P<.05). CONCLUSION. The SM group showed a better fit than the AM and TW groups. However, all values were within the clinical tolerance. Therefore, CAD/CAM manufacturing methods can replace the traditional free-hand wax technique.

• 대한임상검사과학회지
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• 제36권2호
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• pp.121-126
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• 2004

The primary goal of six sigma is to improve patient satisfaction, and thereby profitability, by reducing and eliminating defects. Defects may be related to any aspect of customer satisfaction: high product quality, schedule adherence, cost minimization, process capability indices, defects per unit, and yield. Many six sigma metrics can be mathematically related to the others. Literally, six means six standard deviations from the mean or median value. As applied to quality metrics, the term indicates that failures are at least six standard deviations from the mean or norm. This would mean about 3.4 failures per million opportunities for failure. The objective of six sigma quality is to reduce process output variation so that on a long term basis, which is the customer's aggregate experience with our process over time, this will result in no more than 3.4 defect Parts Per Million(PPM) opportunities (or 3.4 Defects Per Million Opportunities. For a process with only one specification limit (upper or lower), this results in six process standard deviations between the mean of the process and the customer's specification limit (hence, 6 Sigma). The results of applicative six sigma experiment studied on 18 items TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA tests in clinical chemistry were follows. Assessment of process performance fits within six sigma tolerance limits were TP, ALB, T.B, ALP, AST, ALT, CL, CK, LD, K, Na, CRE, BUN, T.C, GLU, AML, CA with 72.2%, items that fit within five sigma limits were total bilirubin, chloride and sodium were 3 sigma. We were sure that the goal of six sigma would reduce test variation in the process.

• 한국기계가공학회지
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• 제12권6호
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• pp.142-151
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• 2013

This study develops an automation system for metallic mold design that is applicable in forging non-axial symmetric parts. The metallic mold design program is used to design the metallic mold using two-dimensional axial symmetric metallic molds and to predict the stress concentration using finite element analyses. Then, the program redesigns the metallic mold using variables such as the optimal split diameter, maximum allowable inner pressure, fit tolerance, and stress distribution, which are calculated using the metallic mold design program. When the involute spur gear is forged, stress concentration occurs on the tooth root bounded at the symmetric surface. The SCM4 material is suitable for metallic molds because the stress is less than the yield strength of the insert and it acts on the tooth root regardless of the inner pressure. The metallic mold for forging non-axial symmetric parts can be designed through adjusting the magnitude of the contact pressure. The program developed in this study can be applied to metallic mold designs in involute spur gears of forging, which is an ordinary non-axial symmetric part.

• Diabetes and Metabolism Journal
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• 제42권6호
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• pp.488-495
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• 2018

Background: Skeletal muscle plays a major role in glucose metabolism. We investigated the association between thigh muscle mass, insulin resistance, and incident type 2 diabetes mellitus (T2DM) risk. In addition, we examined the role of body mass index (BMI) as a potential effect modifier in this association. Methods: This prospective study included 399 Japanese Americans without diabetes (mean age 51.6 years) who at baseline had an estimation of thigh muscle mass by computed tomography and at baseline and after 10 years of follow-up a 75-g oral glucose tolerance test and determination of homeostasis model assessment of insulin resistance (HOMA-IR). We fit regression models to examine the association between thigh muscle area and incidence of T2DM and change in HOMA-IR, both measured over 10 years. Results: Thigh muscle area was inversely associated with future HOMA-IR after adjustment for age, sex, BMI, HOMA-IR, fasting plasma glucose, total abdominal fat area, and thigh subcutaneous fat area at baseline (P=0.033). The 10-year cumulative incidence of T2DM was 22.1%. A statistically significant interaction between thigh muscle area and BMI was observed, i.e., greater thigh muscle area was associated with lower risk of incident T2DM for subjects at lower levels of BMI, but this association diminished at higher BMI levels. Conclusion: Thigh muscle mass area was inversely associated with future insulin resistance. Greater thigh muscle area predicts a lower risk of incident T2DM for leaner Japanese Americans.

• The Journal of Advanced Prosthodontics
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• 제15권2호
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• pp.55-62
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• 2023

PURPOSE. The aim of this study is to evaluate the accuracy of removable partial denture (RPD) frameworks produced using different digital protocols. MATERIALS AND METHODS. 80 frameworks for RPDs were produced using CAD-CAM technology and divided into four groups of twenty (n = 20): Group 1, Titanium frameworks manufactured by digital metal laser sintering (DMLS); Group 2, Co-Cr frameworks manufactured by DMLS; Group 3, Polyamide PA12 castable resin manufactured by multi-jet fusion (MJF); and Group 4, Metal (Co-Cr) casting by using lost-wax technique. After the digital acquisition, eight specific areas were selected in order to measure the Δ-error value at the intaglio surface of RPD. The minimum value required for point sampling density (0.4 mm) was derived from the sensitivity analysis. The obtained Δ-error mean value was used for comparisons: 1. between different manufacturing processes; 2. between different manufacturing techniques in the same area of interest (AOI); and 3. between different AOI of the same group. RESULTS. The Δ-error mean value of each group ranged between -0.002 (Ti) and 0.041 (Co-Cr) mm. The Pearson's Chi-squared test revealed significant differences considering all groups paired two by two, except for group 3 and 4. The multiple comparison test documented a significant difference for each AOI among group 1, 3, and 4. The multiple comparison test showed significant differences among almost all different AOIs of each group. CONCLUSION. All Δ-mean error values of all digital protocols for manufacturing RPD frameworks optimally fit within the clinical tolerance limit of trueness and precision.

• 한국과학교육학회지
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• 제39권2호
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• pp.233-248
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• 2019

본 연구는 칸톤학교 아라우가 19세기 전체에 걸쳐 독일의 김나지움 교육 이념 논쟁과 밀접한 관련이 있음을 보였다. 이 논쟁 속에서 아인슈타인이 바이에른에서 정규 과학교육의 혜택을 거의 받지 못했다는 점을 원전 자료 분석을 통해 입증했다. 아인슈타인은 정규교육의 결핍에도 불구하고 일찍부터 독학에 의해 자기 학습을 하는 습관을 가졌고, 이 방식은 평생 유지되었다. 그는 권위주의적이었던 뮌헨의 학교에서는 매우 힘들게 지냈지만, 자유정신과 자율성이 보장되었던 아라우의 민주적 학교에서는 정서적 안정감을 얻을 수 있었다. 아라우는 오랫동안 외지와 자유로운 교류와 프랑스 계몽주의 영향으로 종교적, 지역적, 민족적 차별이 없이 적대적 사상들에 대해 관대한 다문화적 사상을 갖고 있었다. 이로 인해 소규모 공립학교인 칸톤학교는 스위스를 넘어 교사와 학생의 막강한 인적 자원을 확보할 수 있었고, 교육이념 논쟁을 통해 시대정신에 맞는 실용주의와 계몽주의 사상을 선택했다. 이는 김나지움에서 인간교육-인문주의-엘리트 양성을 실시하고, 상공업학교에서는 시민교육-사실주의-시민 양성을 동시에 독립적으로 운영하는 체제로 정착된다. 특히 김나지움은 1835년부터 순수한 신인문주의를 벗어나 자연사와 같은 실물교과를 도입함으로써 양형주의를 선택하게 되었다. 이로써 칸톤학교는 참다운 인간성 교육, 철저한 학문적 교육, 생활 속에서 시민적 삶의 능력을 추구하는 학교가 되었으며, 아인슈타인은 여기서 진정한 민주주의가 실현되고 자신에게 잊을 수 없는 인상은 남긴 교육기관의 모범을 찾게 된다.

• 한국항공우주학회지
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• 제47권5호
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• pp.344-357
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• 2019

운용상 고장은 제조 시 아무런 문제가 나타나지 않더라도 발생할 수 있으며, 설계 절차에서 고려하지 못했던 환경적 스트레스가 원인일 수 있다. 따라서 환경시험은 이러한 고장의 원인을 판단하기 위해 필수적으로 수행되어야 한다. 또한 환경시험은 군수품이 운용 시 환경적 스트레스로부터 충분한 저항력을 가지고 있는지 판단하는데 사용된다. 본 연구에서는 MIL-STD-810G Change 1기반의 환경시험법과 시험수준을 대한민국에서 운용될 전투기 개발에 맞게 테일러링하여 적용한다. 전투기의 각기 다른 파트는 각각 다른 환경에 노출될 수 있으므로 노출되는 환경이 다른 구성품, 또는 LRUs (Line Replaceable Units) 별로 환경시험을 진행해야 한다. 본 연구에서는 비슷한 환경에 노출되는 LRU 수준에서 시험법 적용여부 및 시험수준의 테일러링 기법을 도출하였으며, 자연, 유도 환경을 나누어 기술하였다. 대한민국에서 운용하는 전투기를 가정하였으므로 한반도의 환경에 맞는 시험법과 시험 수준에 대한 테일러링이 필수적이다. 한 시험법 내에 있는 여러 가지 절차와 시험 수준에 대한 테일러링에 대한 추가적인 연구가 필요하다. 또한 여러 가지의 시험법을 수행할 때 시험순서가 결과에 영향을 미칠 수 있어 환경시험 설계에 있어 필수적인 요소가 되므로 시험순서 결정에 대한 연구도 필요하다.

• 마케팅과학연구
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• 제20권3호
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• pp.269-277
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• 2010

现有文献表明, 影响服务业顾客忠诚的最重要因素是服务质量. 然而, 在服务质量是直接还是间接影响顾客忠诚方面, 学者们的观点有着明显的分歧. 目前, 中国国内专门针对移动通信行业服务质量与顾客忠诚之间关系的文章较少. 此外, 以往相关文献多是将顾客忠诚作为一个整体变量进行研究, 没有进一步将其细分为多个维度. 基于此, 本文拟通过实证研究来探析移动通信业服务质量各维度与顾客忠诚各维度之间的直接和间接影响机理, 其中选择顾客满意作为二者关系的中介变量, 希望研究结论能给国内移动通信企业的服务管理提供有效的理论指导. 为了使搜集到的数据有效, 本次调研范围仅限于黑龙江哈尔滨市, 调查对象为移动通信公司的用户. 本次调研采取随机抽样的方式, 共发放问卷350份, 收回问卷325份, 回收率为 92.9%. 剔除无效问卷, 有效问卷为289份, 即有效回收率为82.6%. 本文借鉴国内外现有文献所使用的量表, 这些量表已经在实证研究中得到验证. 本文提出六个假设, 总体而言, 只有四个假设没有得到支持. 为了验证服务质量构成要素量表的合理性, 本文对289份有效样本进行探索性因子分析. 同样, 对顾客忠诚的维度进行检验. 本研究采用Cronbach's ${\alpha}$系数来评价量表的信度. 本研究从内容效度, 结构效度和聚合效度三方面对问卷进行效度检验. 本研究对数据和模型的拟合优度进行检验, 以提高假设检验的准确程度. 通过文献资料的收集, 整理及数据处理, 本文提出了服务质量五维度模型以及服务质量与顾客忠诚度之间相互关系模型, 通过实证分析验证了有形性, 可靠性, 反应性, 保证性和关怀性是服务质量的五个构成要素, 验证了PZB对于服务质量的SERVQUAL的测量方法, 研究了移动通信服务质量各维度对顾客忠诚各维度的直接影响机理, 以及服务质量各维度如何通过顾客满意这一中介变量对顾客忠诚各维度的间接影响机理, 建立了相应的关系模型,并运用结构方程分析方法,对模型进行实证检验, 得出如下研究结论: 第一, 移动通信服务质量由有形性, 可靠性, 响应性, 保证性和移情性五个要素构成, 顾客忠诚由态度忠诚和行为忠诚两个维度构成. 在PZB设计的SERVQUAL量表基础上, 本文针对移动通信行业设计了服务质量测量量表, 通过探索性因子分析得出五个因子. 这五个因子与五构成要素基本一致, 说明服务质量五要素概念适用于移动通信行业. 同样, 对顾客忠诚量表进行因子分析, 得出两个因子, 与本文中的态度忠诚和行为忠诚相一致. 第二, 移动通信服务质量对顾客忠诚存在直接和间接的正向影响作用. 其中, 服务质量对态度忠诚有直接和间接的正向作用, 间接作用是通过顾客满意这一中介变量影响的; 服务质量对行为忠诚有直接和间接的正向作用, 间接作用是通过顾客满意和态度忠诚这两个中介变量影响的. 这说明移动通信服务质量越好, 顾客的满意度越高, 其对服务提供商的态度就越积极, 在行为上就越容易表现出对服务提供商的忠诚. 而且, 服务质量各维度对顾客忠诚各维度的影响机理是不同的, 比如: 有形性对顾客满意有直接的正向作用, 但对顾客忠诚却没有显著的直接作用; 保证性对顾客满意没有显著的直接作用, 但对顾客忠诚有直接和间接的正向作用. 第三, 顾客满意在移动通信服务质量与态度忠诚, 行为忠诚之间的具有显著的中介作用, 这说明服务质量的提高可以增加顾客的满意度, 而满意的顾客更容易成为忠诚的顾客; 而态度忠诚在移动通信服务质量与行为忠诚之间的具有显著的中介作用, 这说明顾客行为上表现出忠诚可能是虚假忠诚, 只有态度和行为都忠诚的顾客才是真正的忠诚顾客. 本文的研究结论对中国及其它国家的电信运营商如何提升服务质量有一定的借鉴意义. 本文存在两方面的局限性: 首先, 本研究仅在黑龙江哈尔滨地区进行问卷调研, 针对移动公司用户, 统计数据会存在一定的抽样误差, 影响最终的统计分析结果. 第二, 本研究主要探讨了服务质量对顾客忠诚的影响关系, 并引入了顾客满意作为中介变量, 但没有考虑其他可能影响顾客忠诚的因素, 例如顾客价值, 消费者特征等.