• Steel and Composite Structures
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• 제45권3호
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• pp.437-454
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• 2022

Elliptic-braced simple resisting frame as a new lateral bracing system installed in the middle bay of frame in building facades has been recently introduced. This system not only creates a problem for opening space from the architectural viewpoint but also improves the structural behavior. Despite the researches on the seismic performance of lateral bracing systems, there are few studies performed on the effect of the stiffness parameters on the elastic story drift and calculation of period in simple braced steel frames. To overcome this shortcoming, in this paper, for the first time, an analytical solution is presented for calculating elastic lateral stiffness in a simple steel frame equipped with elliptic brace subjected to lateral load. In addition, for the first time, in this study, a precise formulation has been developed to evaluate the elastic stiffness variation in a steel frame equipped with a two-dimensional single-story single-span elliptic brace using strain energy and Castigliano's theorem. Thus, all the effective factors, including axial and shear loads as well as bending moments of elliptic brace could be considered. At the end of the analysis, the lateral stiffness can be calculated by an improved and innovative relation through the energy method based on the geometrical properties of the employed sections and specification of the used material. Also, an equivalent element of an elliptic brace was presented for the ease of modeling and use in linear designs. Application of the proposed relation have been verified through a variety of examples in OpenSees software. Based on the results, the error percentage between the elastic stiffness derived from the developed equations and the numerical analyses of finite element models was very low and negligible.

• Structural Engineering and Mechanics
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• 제84권3호
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• pp.423-435
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• 2022

In this article, we present torsion-bending analysis of a composite FGM beam with an open section, according to the advanced and refined theory of 1D / 3D beams based on the 3D Saint-Venant's solution and taking into account the edge effects. The (initially one-dimensional) model contains a set of three-dimensional (3D) displacement modes of the cross section, reflecting its 3D mechanical behaviour. The modes are taken into account depending on the mechanical characteristics and the geometrical form of the cross-section of the composite FGM beam. The model considered is implemented on the CSB (Cross-Section and Beam Analysis) software package. It is based on the RBT/SV theory (Refined Beam Theory on Saint-Venant principle) of FGM beams. The mechanical and physical characteristics of the FGM beam continuously vary, depending on a power-law distribution, across the thickness of the beam. We compare the numerical results obtained by the three-beam theories, namely: The Classical Beam Theory of Saint-Venant (Classical Beam Theory CBT), the theory of refined beams (Refined Beam Theory RBT), and the theory of refined beams, using the higher (high) modes of distortion of the cross-section (Refined Beam Theory using distorted modes RBTd). The results obtained confirm a clear difference between those obtained by the three models at the level of the supports. Further from the support, the results of RBT and RBTd are of the same order, whereas those of CBT remains far from those of higher-order theories. The 3D stresses, strains and displacements, obtained by the present study, reflect the 3D behaviour of FGM beams well, despite the initially 1D nature of the problem. A validation example also shows a very good agreement of the proposed models with other models (classical or higher-order beam theory) and Carrera Unified Formulation 1D-beam model with Lagrange Expansion functions (CUF-LE).

• Journal of Hospice and Palliative Care
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• 제26권2호
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• pp.42-50
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• 2023

Purpose: The purpose of this study was to identify barriers to effective conversations about advance care planning (ACP) and palliative care reported by health care and community-based service providers in Massachusetts, USA. Methods: This qualitative research analyzed open-ended responses to two survey questions, inquiring about perceived barriers to having conversations about ACP and palliative care with patients and consumers. Data were collected between November 2017 and June 2019 from nine organizations in Massachusetts, including health care provider organizations, health insurers, community-based organizations, and a nursing education institution. Two researchers reviewed and coded the responses and identified common themes inductively. Results: Across 142 responses, primary barriers to ACP included hesitation and lack of understanding and knowledge, discomfort and resistance among service providers, lack of staff knowledge, difficulties with followup, and differences in ACP policies across regions. Common barriers to palliative care were misconceptions about palliative care and lack of knowledge, service providers' lack of preparedness, and limited policy support and availability. Challenges relevant to both ACP and palliative care were fear and discomfort around serious illness discussions, lack of knowledge and awareness, discussions that occur too late, and cultural and language barriers. Conclusion: Health care practitioners and community-based professionals reported consumer-, service provider-, and system-level barriers to facilitating conversations about ACP and palliative care with patients experiencing serious illness. There is a need for more tools and support to strengthen service providers' ACP and palliative care competencies and to promote a structured approach to health care planning conversations.

• Asian Journal of Business Environment
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• 제13권2호
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• pp.1-7
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• 2023

Purpose: The purpose of the study is to explore the factors which influence the night-time economic development in Hanoi, Vietnam. The results can help policymakers achieve a scientific basis to plan the development of night-time economy in Hanoi. Research design, data and methodology: The research model is developed from literature review with 7 independent variables, including natural conditions and resources, infrastructure, safety, environmental issues, promotion and international integration, development of sharing economy, and institution and policy. This model is then adjusted by exploratory factors analysis to have 4 new variables: Institution and environment, Infrastructure and safety, Promotion and sharing, and Nature and resources. The model is regressed based on the data of 463 observations of night-time economy in Hanoi, Vietnam. Results: Consistent with the current literature addressing night-time economy, the results show positive impacts of all of the independent variables studied. Conclusions: It is recommended for the local authorities to strengthen advertising and promoting investment for NTE development in Hanoi city and also enhance the role of state management in NTE activities by raising awareness of the state management apparatus towards a more open-minded multi-dimensional view of the NTE, developing the NTE to overcome the barrier of thinking "if it cannot be managed, it is forbidden" in state management agencies, and defining responsibilities and authority among state management agencies in the management of NTE activities and strengthening decentralization and decentralization of powers for localities in the management and development of NTE.

• 플랜트 저널
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• 제18권4호
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• pp.66-72
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• 2023

신재생에너지 비중 증가에 따른 전력계통 불안정성과 탈원전, 노후 석탄화력 폐쇄로 인한 안정적인 발전자원 감소에 대한 대응 방안으로 터빈제어밸브 4개중 2~3개를 교축하여 발전기 출력 증·감발과 주파수를 추종하는 복합 변압 운전 방식을 터빈제어밸브를 전개하여 교축손실을 줄임으로서 발전 효율을 극대화하는 순 변압운전 방식으로 대체하고, 계통 주파수 변동에 신속하게 대응하기 위해 ESS를 연계하여 주파수 추종 및 자동발전운전을 하는 제어로직을 500MW 석탄화력인 태안 5호기를 대상으로 개발하였다. ESS 운전(신속한 응답, 용량 한계)과 발전소 터빈제어밸브 교축 운전(느린 응답, 지속적인 운전)의 장·단점을 보완하는 협조제어 알고리즘이 실제 발전소에 적용시 발전 효율 향상은 물론 전력 수요에 신속하고 유연하여 대응하여 계통 안정성에 기여할 것으로 확신한다.

• Current Optics and Photonics
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• 제7권1호
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• pp.38-46
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• 2023

Optical Fourier-domain reflectometry (OFDR) sensors have been widely used to measure distances with high resolution and speed in a noncontact state. In the electroplating process of a printed circuit board, it is critically important to monitor the copper-plating thickness, as small deviations can lead to defects, such as an open or short circuit. In this paper we employ a phase-based OFDR sensor for in situ relative distance sensing of a sample with nanometer-scale resolution, during electroplating. We also develop an optical-path difference (OPD)-regulated sensing probe that can maintain a preset distance from the sample. This function can markedly facilitate practical measurements in two aspects: Optimal distance setting for high signal-to-noise ratio OFDR sensing, and protection of a fragile probe tip via vertical evasion movement. In a sample with a centimeter-scale structure, a conventional OFDR sensor will probably either bump into the sample or practically out of the detection range of the sensing probe. To address this limitation, a novel OPD-regulated OFDR system is designed by combining the OFDR sensing probe and linear piezo motors with feedback-loop control. By using multiple OFDR sensors, it is possible to effectively monitor copper-plating thickness in situ and uniformize it at various positions.

• Nuclear Engineering and Technology
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• 제55권4호
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• pp.1439-1447
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• 2023

The fuel cycle characteristics of the IVG.1M reactor were studied within the framework of the research reactor conversion program to modernize the IVG.1M reactor. Optimum use of the nuclear fuel and reactor was achieved through routine methods which included partial fuel reloading combined with scheduled maintenance operations. Since, the additional problem in planning the fuel cycle of the IVG.1M reactor was the poisoning of the beryllium parts of the core, reflector, and control system. An assessment of the residual power and composition of spent fuel is necessary for the selection and justification of the technology for its subsequent management. Computational studies were performed using the MCNP6.1 program and the neutronics model of the IVG.1M reactor. The proposed scheme of annual partial fuel reloading allows for maintaining a high reactor reactivity margin, stabilizing it within 2-4 β_eff for 20 years, and achieving a burnup of 9.9-10.8 MW × day/kg U in the steady state mode of fuel reloading. Spent fuel immediately after unloading from the reactor can be placed in a transport packaging cask for shipping or safely stored in dry storage at the research reactor site.

• 전기전자학회논문지
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• 제26권1호
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• pp.62-66
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• 2022

최근 데이터 기반의 딥러닝 기술을 적용하여 비면허 대역의 다양한 통신 신호를 분류하는 연구가 활발히 수행되고 있다. 하지만, 복잡한 신경망 모델 사용을 기반으로 이뤄진 이러한 접근법은 높은 연산 능력을 필요로 하게 되어, 자원 제약적인 무선 인터페이스 및 사물인터넷(Internet of Things) 장비에서는 사용이 제약된다. 본 연구에서는 비면허 대역의 무선 이기종 기술을 인지하기 위한 데이터 기반의 접근 방법을 살펴보고, 신호의 특징 추출 및 데이터화의 효율화 문제를 다룬다. 구체적으로, 비면허 대역의 다른 종류의 무선 통신 기술을 구분하기 위해 수신 신호 강도 측정을 기반으로 한 시계열 데이터를 이용해 합성곱 신경망(Convolutional Neural Network, CNN) 모델을 학습시켜 신호를 분류하는 방법을 살펴본다. 이 과정에서 동일한 구조의 신경망 모델의 경량화를 위한 효율적 신호의 시계열 데이터 정보 수집시 주파수 대역의 특징을 함께 특징화하는 방법을 제안하고, 그 효과를 평가한다. Bluetooth 호환의 Ubertooth 장비를 이용한 실측 기반의 실험 결과는 제안된 샘플링 기법이 동일한 신경망에 대해서 10% 수준의 샘플링 데이터 이용만으로도 동일한 정확도를 유지함을 보여준다.

• 디지털융복합연구
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• 제20권3호
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• pp.317-323
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• 2022

본 연구의 목적은 4차 산업 스마트팜 관련 벤처기업의 혁신 설비 투자, 혁신 연구인력 역량이 특허, 디자인등록의 기술성과와 매출 영업이익 재무성과에 어떤 영향을 미치는지 분석하였다. 연구 방법으로 총 47개 벤처업체를 표본으로 선정하여 회귀분석을 수행하였다. 연구 결과 본 연구는 4차 산업 스마트팜 관련 벤처기업의 기술사업화 요인을 분석하여 재무적 기술적 성공 기업성과를 위해서 R&D 정부 과제 예산편성 확대를 제안한다. 향후 연구 방향은 기업의 양적인 성장 기여와 질적인 성장 기여에 대한 논의가 더욱 필요할 것이라고 본다.

• 예술인문사회 융합 멀티미디어 논문지
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• 제7권11호
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• pp.305-314
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• 2017

본 연구의 목적은 교육복지우선지원사업의 실태를 파악하고, 향후 사업이 나아갈 방향을 제시하는데 있다. 연구목적을 위해 온라인 설문조사를 실시하고 관련 문헌연구, 교육복지우선지원사업 담당자를 대상으로 한 심층면담, 17개 시도교육청 및 교육부 관계자를 대상으로 한 세미나를 실시하여 결과를 보완하였다. 이를 근거로 현 상태를 진단하고 향후 해결해야할 과제를 제시하였다. 연구결과, 교육복지우선지원사업은 2003년 교육복지투자우선지역 지원사업을 시작으로 사업의 효과성이 증명되면서 지속적으로 확대되었다. 그리고 초중등교육법 시행령 개정 및 교육부 훈령 제정 등을 통해 법적, 제도적 안정성을 확보해 나갔다. 하지만 시도교육청으로 사업이 이양된 이후 사업이 활성화되지 못하고 점차 축소되고 정체성의 위기마저 겪고 있는 것으로 파악되었다. 본 연구에서는 이러한 결과를 종합하여 향후 해결해야 할 과제로 분명한 사업의 목적과 방향설정, 중앙정부의 기능 정상화, 초중등교육법 제28조 개정을 통한 '학습부진아 등'의 개념보완을 제시하였다.