• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.528-532
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• 2006

In the aerospace industry, Cold expansion has been used the most important method that is retarded of crack initiation from fastener hole surface. Cold expansion method(CEM) is that a oversized tapered mandrel goes through the hole in order to develop a compressive residual stress as the passing of the mandrel around the hole. Therefore, because of characteristic of mandrel inserting, Residual Stress Distributions (RSD) are differently generated form Entry, Mid and Exit position of the plate. Also, it is respected that RSD are changed as distances between holes. In this paper, It is performed a FE analysis of RSD by CEM and it is respectively shown RSD in the Entry, Mid and Exit position. It is compared residual stress results form the cold expansion in these two cases: the concurrent CEM and the sequential CEM. From this research, it has been found that compressive residual stress of Entry position is lower than other positions. Also, the concurrent CE of adjacent holes leads to much higher compressive residual stress than the sequential CE. In addition, in the sequential CE case, a compressive RSD of 1 step's hole around is lower than compressive RSD of 2 step's hole around.

• The Korean Journal of Physiology and Pharmacology
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• v.1 no.4
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• pp.457-466
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• 1997

The effects of DFMO or/and putrescine on the dexamethasone-induced apoptosis of CEM cells were studied to investigate the role of polyamines in anti-leukemic glucocorticoid action. Dexamethasone- induced apoptosis was preceded by significant decreases of cellular polyamine contents and putrescine uptake activity. But DFMO produced decreases of putrescine and spermidine contents and marked increase of putrescine uptake activity, but did not induce apoptosis. However, dexamethasone and DFMO, respectively, induced $G_1-arrest$ in cell cycle and hypophosphorylation of pRb, resulting in the increase of $G_1$ to S ratio and decrease of CEM cell count. DFMO enhanced the dexamethasone-induced apoptosis and $G_1-arrest$. On the other hand, putrescine little affected the apoptotic and $G_1-arresting$ activities of dexamethasone, but almost suppress the effects of DFMO and also the DFMO-dependent enhancement of dexamethasone effects. These results suggested that the dexamethasone-induced apoptosis to be associated with pRb hypophosphorylation and $G_1-arrest$ in CEM cells might be ascribed to the concomitant decreases of cellular polyamine contents and putrescine uptake activity.

• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.1-13
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• 2015

Advancements in bio-ceramic technology has revolutionised endodontic material science by enhancing the treatment outcome for patients. This class of dental materials conciliates excellent biocompatibility with high osseoconductivity that render them ideal for endodontic care. Few recently introduced bio-ceramic materials have shown considerable clinical success over their early generations in terms of good handling characteristics. Calcium enriched mixture (CEM) cement, Endosequence sealer, and root repair materials, Biodentine and BioAggregate are the new classes of bio-ceramic materials. The aim of this literature review is to present investigations regarding properties and applications of CEM cement in endodontics. A review of the existing literature was performed by using electronic and hand searching methods for CEM cement from January 2006 to December 2013. CEM cement has a different chemical composition from that of mineral trioxide aggregate (MTA) but has similar clinical applications. It combines the biocompatibility of MTA with more efficient characteristics, such as significantly shorter setting time, good handling characteristics, no staining of tooth and effective seal against bacterial leakage.

• The Journal of Economics, Marketing and Management
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• v.4 no.2
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• pp.1-19
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• 2016

The purpose of this study was to examine the issues involved in offering superior customer experience on fashion retail stores in Brazil. The approach used to access CEM (Customer Experience Management) issues was a special questionnaire with 23 questions, through a research with managers of three important brazilian fashion retail chains (focused on class A clients). Some statistical techniques were used for data processing. It was possible to analyze the aspects that impact on the customer experience and their relevance. it was possible to realize that CEM is effective in increasing productivity and, so, it can be used as a guideline matrix management in decision making to promote superior customer experiences. The classical management is usually conservative and avoids to deal with strategies that do not necessarily involve numbers. Dealing with intangible and so subtle experience is unusual and a huge challenge, but sometimes it is necessary to look beyond the obvious and accessible statistics. If CEM is a strategy to focus on operations and processes of a business around the customers experiences with the company, it is essential to structure it and find out its effectiveness.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.4
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• pp.1-6
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• 2005

The ability to predict radar return from flying vehicles becomes a critical technology issue in the development of stealth configurations. Toward developing a CEM code based on Maxwell's equations for analysis of RCS reduction schemes, an explicit upwind scheme suitable for multidisciplinary design is presented. The DFFT algorithm is utilized to convert the time-domain field values to the frequency-domain. A Green's function based on near field-to-far field transformation is also employed to calculate the bistatic RCS. To verify the numerical calculation the two-dimensional field around a perfectly conducting cylinder is considered. Finally results are obtained for the scattering electromagnetic field around an airfoil in order to illustrate the feasibility of applying CFD based methods to CEM.

• The Journal of Advanced Prosthodontics
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• v.12 no.2
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• pp.89-99
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• 2020

PURPOSE. The effects of four different self-adhesive resin cement materials on cell viability and apoptosis after direct and indirect exposure were evaluated using different cell culture techniques. MATERIALS AND METHODS. Self-adhesive cements were applied to NIH/3T3 mouse fibroblasts by the extract test method, cell culture inserts, and dentin barrier test method. After exposure periods of 24 h and 72 h, the cytotoxicity of these self-adhesive materials was evaluated using the MTT assay (viability) and the Annexin-V-FITC/PI staining (apoptosis). RESULTS. The lowest cell viability was found in cells exposed to BeautiCem SA for 24 h in the extract test method. Cell viability was reduced to 70.6% compared to negative controls. After the 72 h exposure period, viability rate of cell cultures exposed to BeautiCem SA decreased more than 2- fold (29.5%) while cells exposed to RelyX U200 showed the highest viability rate of 71.4%. In the dentin barrier test method, BeautiCem SA induced the highest number of cells in apoptosis after a 24 h exposure (4.1%). Panavia SA Cement Plus was the material that caused the lowest number of cells in apoptosis (1.5%). CONCLUSION. The used self-adhesive cements have showed different cytotoxic effects based on the evaluation method. As exposure time increased, the materials showed more cytotoxic and apoptotic effects. BeautiCem SA caused significantly more severe cytotoxic and apoptotic effects than other cements tested. Moreover, cements other than BeautiCem SA have caused necrotic cell death rather than apoptotic cell death.

• Structural Engineering and Mechanics
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• v.65 no.1
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• pp.91-98
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• 2018

Three structure-dependent integration methods with no numerical dissipation have been successfully developed for time integration. Although these three integration methods generally have the same numerical properties, such as unconditional stability, second-order accuracy, explicit formulation, no overshoot and no numerical damping, there still exist some different numerical properties. It is found that TLM can only have unconditional stability for linear elastic and stiffness softening systems for zero viscous damping while for nonzero viscous damping it only has unconditional stability for linear elastic systems. Whereas, both CEM and CRM can have unconditional stability for linear elastic and stiffness softening systems for both zero and nonzero viscous damping. However, the most significantly different property among the three integration methods is a weak instability. In fact, both CRM and TLM have a weak instability, which will lead to an adverse overshoot or even a numerical instability in the high frequency responses to nonzero initial conditions. Whereas, CEM possesses no such an adverse weak instability. As a result, the performance of CEM is much better than for CRM and TLM. Notice that a weak instability property of CRM and TLM might severely limit its practical applications.

• Review of KIISC
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• v.14 no.4
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• pp.68-77
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• 2004

국가 사회 각 분야(정부, 공공기관 및 민간기관)의 정보보호시스템에 의한 정보처리 의존도가 증가하고 있으며 정보보호 수준강화를 위한 평가업무의 수요 또한 늘어가고 있다. 이에 발맞추어 현재 정보보호시스템 평가에 대한 상호인증을 위해 공통평가기준(CC : Common Criteria)과 공통평가방법론(CEM : Common Evaluation Methodology)을 사용하고 있다. 본 논문에서는 정보보호시스템의 신뢰성의 확보와 상호인증을 위한 지침으로써 CC와 CEM에 대한 변화과정 및 특징을 분석하였으며 앞으로 이를 반영한 국제동향에 능동적인 대처와 효율적인 평가에 기여할 것으로 기대된다. 또한, 평가참여자(평가신청자, 개발자, 평가자, 감독자 등)의 역할도 변화의 흐름에 유연하게 대응해야 하며 이러한 지식을 토대로 객관적이며 체계적인 평가계획을 수립하는데 이용할 수 있을 것이다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10a
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• pp.397-399
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• 2004

오늘날 조직에서 공개된 소프트웨어를 이용한 오픈소스 내포형 정보보호시스템(OSS-embedded Information Security System) 개발이 증가되고 있으며 소스의 상당부분을 오픈소스 소프트웨어(OSS : Open source Software)를 이용함으로써 복잡한 IT환경 속에서 효율성 증대와 고가의 라이센스에 대한 비용 절감 효과 등을 통해 높은 시장성이 예상된다. 그러므로 오픈소스 내포형 정보보호시스템에 대한 평가 제출물 준비 및 평가에 대한 기준을 정의할 필요가 있으며 공통평가기준(CC : Common Criteria)과 공통평가방법론(CEM : Common Evaluation Methodology)에서 유도한 OSS 평가요구사항을 분석하고자 한다.

• Journal of Dental Rehabilitation and Applied Science
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• v.31 no.1
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• pp.1-9
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• 2015

Purpose: The purpose of this study was to evaluate the mechanical properties of several dual-cure cements by different curing modes. Materials and Methods: One resin-modified glass ionomer cement (FujiCEM 2), two conventional dual-cure resin cements (RelyX ARC, Multilink N), and two dual-cure self-adhesive resin cements (RelyX U200, G-CEM LinkAce) were used. To evaluate the influence of the curing methods, each cements divided into four conditions (n = 20); Condition 1: self-curing for 10 minutes, Condition 2: immediate after 20 seconds light-curing, Condition 3: 24 hours after self-curing, Condition 4: 24 hours after light-curing. The compressive strength and diametral tensile strength were measured with a universal testing machine. All data were statistically analyzed using t-test, one-way ANOVA and Scheffe's test. Results: The results showed the compressive strength and diametral tensile strength after 24 hours in all curing modes were higher than immediate except RelyX ARC light-cured and Multilink N light-cured. The FujiCEM 2 showed lowest values (P < 0.05). Conclusion: The outcome was cement-depend, but there is no significant difference about compressive strength and diametral tensile strength between dual-cure self-adhesive resin cements and conventional resin cements. And this result will be used as a base line data selecting resin cement for favorable long-term prognosis.