• Computers and Concrete
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• 제26권2호
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• pp.185-201
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• 2020

This research is devoted to investigate the bending and free vibration behaviour of laminated composite/sandwich plates and shells, by applying an analytical model based on a generalized and simple refined higher-order shear deformation theory (RHSDT) with four independent unknown variables. The kinematics of the proposed theoretical model is defined by an undetermined integral component and uses the hyperbolic shape function to include the effects of the transverse shear stresses through the plate/shell thickness; hence a shear correction factor is not required. The governing differential equations and associated boundary conditions are derived by employing the principle of virtual work and solved via Navier-type analytical procedure. To verify the validity and applicability of the present refined theory, some numerical results related to displacements, stresses and fundamental frequencies of simply supported laminated composite/sandwich plates and shells are presented and compared with those obtained by other shear deformation models considered in this paper. From the analysis, it can be concluded that the kinematics based on the undetermined integral component is very efficient, and its use leads to reach higher accuracy than conventional models in the study of laminated plates and shells.

• 전력전자학회논문지
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• 제18권1호
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• pp.10-17
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• 2013

In this paper, a new active damping method of LCL filter without capacitor voltage sensors is proposed for 3 phase PWM Inverter. Normally, L filter or LCL filter is used as an output filter of grid connected PWM inverter. An LCL filter has more excellent performance than L filter to reduce harmonic current, so the small inductance value can be used. However, the resonance problem in LCL filter is happen due to the zero impedance by the addition of LC branch. To solve the resonance problem, the various active damping method has been proposed so far. Generally, the virtual resistor active damping methods is required to additional hardware sensors for measurement of capacitor voltage and current. In this paper, the new active damping method is proposed without any capacitor voltage or current sensors. In the proposed method, the resonance component of the capacitor voltage of LCL filter can be observed by a simple MRAS(Model Reference Adaptive System) observer without additional hardware sensors, and this component is suppressed by feedforward compensation. The validity of the proposed method is proven by simulation and experiment on the 3-phase PWM inverter system.

• 한국통신학회논문지
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• 제31권12B호
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• pp.1044-1048
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• 2006

본 논문에서는 중복 객체를 사용하는 FTOG(Fault-tolerant Object Group) 모델 기반의 회복서비스를 제안한다. 분산 시스템 환경에서 객체의 고장 발생시 시스템의 전체 고장 상태를 초래하여 신뢰성 있는 서비스를 제공하지 못할 수 있다. 따라서 본 논문에서는 고장이 발생할 경우 고장 발견자를 사용하여 고장을 인지하고, 다른 서비스 객체를 실행시키는 회복서비스를 제안한다. 또한 가상의 홈네트워크 환경에 FTOG 모델을 적용시켜 시뮬레이션을 통해 분산되어 있는 객체들의 관리와 고장 발견자를 사용하여 고장 발생시 중복 객체 메커니즘에 의한 회복 과정 등 본 모델의 안정성 및 신뢰성을 검증한다.

• 반도체디스플레이기술학회지
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• 제22권4호
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• pp.7-12
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• 2023

The edge ring placed on the outside of the electrostatic chuck (ESC) is a key component for protecting the ESC and controlling the etching uniformity of the edge of the wafer. Therefore, it is very important to understand the etching phenomenon of edge rings for edge ring management and equipment homeostasis. In this study, a specimen with SiO₂ hard mask and underlying Si mold was installed on the edge ring surface and the etching results were measured by varying the edge ring 2MHz RF power. By developing PI-VM model with high prediction accuracy and analyzing the roles of key parameters in the model, we were able to evaluate the effect of plasma and sheath characteristics around the edge ring on edge ring erosion. This analysis method provided information necessary for edge ring maintenance and operation.

• 마케팅과학연구
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• 제20권3호
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• pp.262-268
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• 2010

虚拟社区(virtual community, VC)今年来发展迅速, 越来越多的人参与到虚拟社区中交换信息和分享观点. 虚拟社区是通过计算机布告板和网络进行非面对面的知识和语言交流的一种大众集合体. B2C电子商务网站虚拟社区则是商业性的虚拟社区, 通过培养信任环境来促进消费者在该网站的购买行为. B2CVC通过信息交流, 如推荐, 评论, 买者与卖者评级等, 来建立社会性的氛围. 目前, 虽然学术界已经认识到B2CVC的重要性, 但是关于社区成员的口碑传播行为的研究还不充分. 本研究提出了一个理论模型, 探讨在B2C网站社区中参与度, 满意度, 信任度, 粘度和口碑传播之间的关系. 本研究的目的有三个: 1, 通过整合信念, 态度和行为的测量来实证检验B2C网站社区模型; 2, 更好地理解各因素对口碑传播的影响关系; 3, 更好地理解B2C网站社区黏度在CRM营销中的作用. 研究模型包含以下要素: 1, 社区成员的信念变量, 通过参与度来测量; 2, 社区成员的态度变量, 通过满意度和信任度来测量; 以及3, 社区成员的行为变量, 通过网站黏度和口播传播意愿来测量. 参与度是消费者在虚拟社区的参与动机. 对于社区成员来说, 信息的查找和发布是他们参与到社区的主要目的. 满意度是成员对社区整体评价的重要指标, 反映了成员与社区的交互程度. 虚拟社区的形成与发展依靠成员分享信息和服务的自愿程度. 研究者已经发现信任是促进匿名交互的关键, 因此构建信任被看作是虚拟社区的重要研究课题. 此外, 虚拟社区的成功依靠成员的粘度来提高购买潜力. 社区成员间的观点交流和信息交换代表一种 "写作式" 的口碑传播. 因此口碑传播是推动B2C虚拟社区在互联网上扩散的主要因素之一. 研究模型及假设如图一所示. 本研究通过实证调查中国携程旅游网虚拟社区成员来验证模型. 数据收集过程中共发放243份问卷, 其中有效问卷204份. 通过实证数据验证了参与度, 满意度和信任度影响粘度和口碑传播之间的假设关系. 结构方程模型(SEM)方法用来进行数据分析. 模型的拟合指数结果为χ2/df 是2.76, NFI是 .904, IFI是 .931, CFI是 .930, 以及RMSEA是 .017. 结果表明, 参与度对满意度具有显著的影响(p<0.001, ${\beta}$=0.809). 参与度可以解释满意度的方差比例超过50%, 调整R2为0.654. 参与度对信任度具有显著影响(p<0.001, ${\beta}$=0.751), 解释率为57%, 调整R2为0.563. 此外, 满意度对黏度的影响显著(${\beta}$=0.514), 但是信任度对黏度的影响并不显著(p=0.231, t=1.197). 黏度对口碑传播的影响显著, 且解释率超过80%, 调整R2为 0.846. 总之, 研究结果支持了大部分的研究假设, 但是信任度显著影响粘度的假设没有得到支持. 本研究丰富了电子商务网站虚拟社区的学术研究成果, 深入探讨了在B2C电子商务环境下的用户信念, 态度和行为等因素. 研究成果有助于实践者进行更有针对性的资源开发和市场开拓. 网络营销人员可以针对B2C网站社区来有针对性地制定营销策略, 如对于国际旅游业务, 营销人员可以针对中国的B2C网站社区用户开展营销活动, 如为活跃的用户提供特殊折扣以及为早期参与者提高社区黏度定制营销计划等. 未来的研究应该拓展社区成员行为的研究, 并在不同的行业, 社区和文化背景下开展研究.

• Archives of Plastic Surgery
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• 제45권5호
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• pp.395-402
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• 2018

Increased emphasis on competency-based learning modules and widespread departure from traditional models of Halstedian apprenticeship have made surgical simulation an increasingly appealing component of medical education. Surgical simulators are available in numerous modalities, including virtual, synthetic, animal, and non-living models. The ideal surgical simulator would facilitate the acquisition and refinement of surgical skills prior to clinical application, by mimicking the size, color, texture, recoil, and environment of the operating room. Simulation training has proven helpful for advancing specific surgical skills and techniques, aiding in early and late resident learning curves. In this review, the current applications and potential benefits of incorporating simulation-based surgical training into residency curriculum are explored in depth, specifically in the context of plastic surgery. Despite the prevalence of simulation-based training models, there is a paucity of research on integration into resident programs. Current curriculums emphasize the ability to identify anatomical landmarks and procedural steps through virtual simulation. Although transfer of these skills to the operating room is promising, careful attention must be paid to mastery versus memorization. In the authors' opinions, curriculums should involve step-wise employment of diverse models in different stages of training to assess milestones. To date, the simulation of tactile experience that is reminiscent of real-time clinical scenarios remains challenging, and a sophisticated model has yet to be established.

• 한국지능시스템학회논문지
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• 제14권7호
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• pp.801-806
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• 2004

감성 인식 기술은 사회의 여러 분야에서 요구되고 있는 필요한 기술이지만, 인식 과정의 어려움으로 인해 풀리지 않는 문제로 낡아있다. 특히 얼굴 영상을 이용한 감정 인식 기술에서 얼굴 영상을 분석하는 기술 개발이 필요하다. 하지만 얼굴분석을 어려움으로 인해 많은 연구가 진행 중이다. 된 논문에서는 감정 인식을 위한 얼굴 영상 분석 알고리즘을 제안한다. 제안된 얼굴 영상 분석 알고리즘은 얼굴 영역 추출 알고리즘과 얼굴 구성 요소 추출 알고리즘으로 구성된다. 얼굴 영역 추출 알고리즘은 다양한 조명 조건에서도 강인하게 얼굴 영역을 추출할 수 있는 퍼지 색상 필터를 사용한 방법을 제안하였다. 또한 얼굴 구성 요소 추출 알고리즘에서는 가상 얼굴 모형을 이용함으로써 보다 정확하고 빠른 얼굴 구성 요소 추출이 가능하게 하였다. 최종적으로 모의실험을 통해 각 알고리즘들의 수행 과정을 살펴보았으며 그 성능을 평가하였다.

• 시스템엔지니어링학술지
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• 제13권1호
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• pp.15-23
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• 2017

This paper describes verification of APR1400 reactor vessel by applying the system engineering approach, in which the design re-engineering method is used to check the design parameters of APR1400 RV (reactor vessel). The RV is classified as safety class 1 and therefore must adhere strictly to the rules of ASME BPVC section III, subsection NB and seismic category I. This study explores designing the RV by following the ASME guidelines and making a comparative study with the current design. To meet this objective we apply system engineering methodologies to structure the process and allow for verification and validation of the major RV design parameters such as thickness of RV. The structural thicknesses of various part of RV are determined as well as reinforcements on the RV major nozzles. A 3D virtual reality model was created based on the design parameters using CATIA V5 and animation using Dassault Composer V2016. A comparison of re-engineered ARP1400 RV and standard APR1400 RV was done to show which design parameters were taken more conservative approach.

• 시스템엔지니어링학술지
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• 제12권1호
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• pp.89-103
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• 2016

Due to safety of the plant, it became very clear the importance of study occurrence reactor coolant system (RCS) issues specially the primary water stress corrosion cracking (PWSCC). The Systems Engineering (SE) approach is characterized by the application of a structured engineering methodology for the design of a complex system or component. Robotic devices have been used for internal inspection, maintenance and performing remote welding and inspection in high-radiation areas. In this paper, PWSCC overview and inlay and over lay welding methodology introduced, concept of robotic device that can be inserted into the piping via Steam Generator (SG) main way to access to primary piping of pressurized water reactor (PWR) is developed based on SE methodology. A 3D model of the inspection system was developed along with the APR1400 (Advanced Power Reactor)reactor coolant systems (RCS) and internals with virtual 3D simulation of the operation for visualization to prove the validity of the concept.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2003년도 춘계종합학술대회논문집
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• pp.356-360
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• 2003

다양한 종류의 컨텐츠 데이터베이스를 구축하고, 이를 인터넷 서비스로 제공하는 인터넷 포탈 서비스 응용이나 전자상거래 등에서 기존에 구축되어 있는 여러 형태의 컨텐츠 데이터베이스들을 통합하여 새로운 컨텐츠 서비스를 제공하기 위한 많은 노력들이 수행되고 있다. 이는 사용자가 활용하려는 컨텐츠가 어떤 데이터베이스 또는 어느 인터넷 서비스 응용에서 제공되는지를 파악해야 하는 사용자의 부담을 줄이고, 다수의 컨텐츠 데이터베이스들을 사용자에게 단일한 뷰(view)를 제공하므로서 사용자 이용 편의성을 높일 수 있다. 본 논문에서는 다양한 컨텐츠 데이터베이스들이 인터넷에 분산되어 있을 뿐만 아니라 서로 상이한 데이터베이스 시스템들(즉, 관계형 DB/객체형 DB)에서 관리되는 환경에서 XML자료 모델을 기반으로 통합된 하나의 가상 데이터베이스를 구축하고 검색하는 통합 검색 시스템의 핵심 요소인 질의 처리 시스템을 설계 및 구현한다.