• 전산구조공학
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• 제9권1호
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• pp.151-159
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• 1996

구조용 콘크리트의 비선형 거동을 예측하기 위하여, 압축강도 연화현상, 거시적 및 회전균열모델등의 내용을 포함하고 있는 압축장 응력장 이론(CFT)에 근거한 유한요소법이 개발/제시되었다. 또한, 이와 관련하여 CFT가 암시하는 탄젠트 및 세칸트 재료강성이 반복계산해법의 관점에서 정의/논의되었다. 최종적으로 계산상의 효율성 증대 및 최대하중 이후의 거동 포착에 주안점을 두어 초기재료 강성을 채택한 변위증분법 논리 및 빠른 수렴을 위한 Over-Relaxtion방법이 Isoparametric계의 8-Node요소에 포함/유도되었다. 이와 같이하여 제시된 비선형 해석 프로그램 NASCOM은 응력 혼돈지역에 위치하는 콘크리트 평면요소의 하중 지지능력, 탄성범위 이후의 변형 특성, 균열양상 및 보강근의 항복범위등의 예측을 가능하게 하였다. NASCOM의 제한된 검증을 위하여, Cervenka의 판넬 시험결과에 대한 하중지지능력 및 변형이력등을 예측한 결과가 전체적인 의미에서 실험결과와 상응하는 일치를 나타내었다.

• Earthquakes and Structures
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• 제13권3호
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• pp.267-277
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• 2017

Base-isolation is now being adopted as a retrofitting strategy to improve seismic behaviour of reinforced concrete (r.c.) framed structures subjected to far-fault earthquakes. However, the increase in deformability of a base-isolated framed building may lead to amplification in the structural response under the long-duration horizontal pulses of high-magnitude near-fault earthquakes, which can become critical once the strength level of a fire-weakened r.c. superstructure is reduced. The aim of the present work is to investigate the nonlinear seismic response of fire-damaged r.c. framed structures retrofitted by base-isolation. For this purpose, a five-storey r.c. framed building primarily designed (as fixed-base) in compliance with a former Italian seismic code for a medium-risk zone, is to be retrofitted by the insertion of elastomeric bearings to meet the requirements of the current Italian code in a high-risk seismic zone. The nonlinear seismic response of the original (fixed-base) and retrofitted (base-isolated) test structures in a no fire situation are compared with those in the event of fire in the superstructure, where parametric temperature-time curves are defined at the first level, the first two and the upper levels. A lumped plasticity model describes the inelastic behaviour of the fire-damaged r.c. frame members, while a nonlinear force-displacement law is adopted for the elastomeric bearings. The average root-mean-square deviation of the observed spectrum from the target design spectrum together with a suitable intensity measure are chosen to select and scale near- and far-fault earthquakes on the basis of the design hypotheses adopted.

• International Journal of Computer Science & Network Security
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• 제24권5호
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• pp.172-180
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• 2024

Since the beginning of 2015, corporate social responsibility (CSR) models have been changing in connection with the trend towards the transition of joint value creation of corporate activities and consideration of stakeholders' interests. The purpose of the academic paper lies in empirically studying the current practice of social responsibility of transnational corporations (TNCs). The research methodology has combined the method of qualitative analysis, the method of cases of agricultural holdings in emerging markets within the framework of resource theory, institutional theory and stakeholders' theory. The results show that the practice of CSR is integrated into the strategy of sustainable development of TNCs, which determine the methods, techniques and forms of communication, as well as areas of stakeholders' responsibility. The internal practice of CSR is aimed at developing norms and standards of moral behaviour with stakeholders in order to maximize economic and social goals. Economic goals are focused not only on making a profit, but also on minimizing costs due to the potential risks of corruption, fraud, conflict of interest. The system of corporate social responsibility of modern TNCs is clearly regulated by internal documents that define the list of interested parties and stakeholders, their areas of responsibility, greatly simplifying the processes of cooperation and responsibility. As a result, corporations form their own internal institutional environment. Ethical norms help to avoid the risks of opportunistic behaviour of personnel, conflicts of interest, cases of bribery, corruption, and fraud. The theoretical value of the research lies in supplementing the theory of CSR in the context of the importance of a complex, systematic approach to integrating the theory of resources, institutional theory, theory of stakeholders in the development of strategies for sustainable development of TNCs, the practice of corporate governance and social responsibility.

• 한국콘텐츠학회논문지
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• 제14권12호
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• pp.1100-1116
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• 2014

본 연구에서는 '스크린 위의 글쓰기' 과정에서 아동이 예상독자를 어떻게 고려하며, 글쓰기 공동체의 의사소통의 중심에 있는 댓글은 독자와의 관계에서 어떤 수행성을 나타내는지 조사하였다. 이를 위해 초등학교 4-6학년 아동의 게시 글에서 635개의 문장과 424개의 댓글을 수집하여 분석하였다. 연구 결과, 아동의 예상독자를 고려한 글쓰기 전략은 끌어들이기 전략이 가장 많이 나타났고, 세부 전략으로는 감정에 호소하는 전략이 가장 많이 사용되었으며, 댓글의 수행행위는 표출 행위가 가장 많이 나타났다. 또한 아동의 PAIR 전략은 회기가 진행되면서 증가하였다가 다시 감소하는 양상을 보였으며, 아동은 게시 글을 작성할 때 다양한 방식으로 복합양식을 사용하는 것으로 나타났다. 한편, 댓글에 나타나는 의사소통의 특성 역시 감정적이고 정서적인 표현에 치우쳐져 있었으며, 아동의 댓글에는 저자 및 제 3의 독자들을 예상한 의사소통이 이루어졌고, 게시 글과 관련된 의견 교류뿐만 아니라, 아동의 일상적인 문화가 반영되어 나타났다.

• 융합보안논문지
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• 제13권6호
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• pp.51-59
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• 2013

3.20, 6.25 등 사이버공격을 받은 우리 정부는 지난 공격의 배후를 지목했으나, 공격행위에 대한 처벌이나 제제에 대해 논할 수 있는 국제적 논의의 장은 없었다. 이렇게 특정 국가가 공격을 주도했음을 입증하는 증거를 갖고 있더라도 규탄, 제재, 처벌 등이 불가능했기에 에스토니아 사태 이후 지속적으로 유사한 악의적 행위들이 반복되고 있다. 현재 사이버안보에 관한 국제적 논의는 크게 국제적 수준, 지역적 수준 및 양자간 협력의 3계층으로 나뉘어 진행되고 있다. 이 중 국제적 사이버안보 규범 논의 방향 정립은 주로 국제연합과 세계 사이버스페이스 총회 2개 축으로 움직이고 있다. 물론 민간 중심의 인터넷 거버넌스 논의나 UN 전문기구인 국제전기통신연합 등에서도 사이버보안 이슈가 논의되고 있으나 본 논문에서는 2013년 주요 성과가 도출된 국제연합의 정부전문가그룹(GGE) 활동 결과와 우리 정부가 주최한 제3차 세계 사이버스페이스 총회의 사이버안보 논의 흐름을 분석하여 2014년부터 시작될 제4차 UN 전문가그룹(GGE)의 활동을 예상해보고 앞으로의 사이버안보 논의 방향을 짚어보고자 한다. 또한 이러한 논의들에 대한 국내 대응전략을 도출해보고자 한다.

• Advances in nano research
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• 제6권1호
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• pp.1-19
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• 2018

Iron oxide nanoparticles excite researcher interest in biomedical applications due to their low cost, biocompatibility and superparamagnetism properties. Magnetic iron oxide especially magnetite ($Fe_3O_4$) possessed a superparamagnetic behaviour at certain nanosize which beneficial for drug and gene delivery, diagnosis and imaging. The properties of nanoparticles mainly depend on their synthesis procedure. There has been a massive effort in developing the best synthetic strategies to yield appropriate physico-chemical properties namely co-precipitation, thermal decomposition, microemulsions, hydrothermal and sol-gel. In this review, it is discovered that magnetite nanoparticles are best yielded by co-precipitation method owing to their simplicity and large production. However, its magnetic saturation is within range of 70-80 emu/g which is lower than thermal decomposition and hydrothermal methods (80-90 emu/g) at 100 nm. Dimension wise, less than 100 nm is produced by co-precipitation method at $70^{\circ}C-80^{\circ}C$ while thermal decomposition and hydrothermal methods could produce less than 50 nm but at very high temperature ranging between $200^{\circ}C$ and $300^{\circ}C$. Thus, co-precipitation is the optimum method for pre-compliance magnetite nanoparticles preparation (e.g., 100 nm is fit enough for biomedical applications) since thermal decomposition and hydrothermal required more sophisticated facilities.

• The Journal of Asian Finance, Economics and Business
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• 제5권3호
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• pp.65-72
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• 2018

The purpose of this paper is to understand the influence of country personality dimensions and product involvement on European consumers purchase and visit intentions, considering the Portuguese context. The increasing economic globalisation has resulted in the reducing of trade barriers between nations and the availability of more foreign products and services across borders. Therefore, the place associations of these products and services might be regarded as a potential competitive differentiator in their respective markets. Despite the proliferation of literature devoted to assessing the effects of country-of-origin, the symbolic dimension of a country's image remains understudied. A questionnaire measuring country personality dimensions, product involvement, and consumer's purchase and visit intention was passed on a sample of 335 European consumers. Country personality indeed matters both positively and negatively. Findings show that while assiduousness positively influences consumer's visit intentions, wickedness has a negative influence on consumer's purchase intentions. Findings also reveal that product involvement has a positive significant influence on consumer's purchase and visit intentions. On developing marketing strategies, international marketers and governmental decision-makers should consider product involvement attributes and specific country personality traits to provide the country's products with a competitive edge, as well as to promote the country as a travelling destination.

• Earthquakes and Structures
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• 제11권5호
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• pp.809-822
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• 2016

Reinforced concrete buildings constitute the majority of the building stock of Turkey and much of them, do not comply the earthquake codes. Recently there is a great tendency for strengthening to heal their earthquake performance. The performance evaluations are usually executed by the numerical investigations performed in computer packages. However, the numerical models are often far from representing the real behaviour of the existing buildings. In this condition, experimental modal analysis fills a gap to correct the numerical models to be used in further analysis. On the other hand, there have been a few dynamic tests performed on the existing reinforced concrete buildings. Especially forced vibration survey is not preferred due to the inherent difficulties, high cost and probable risk of damage. This study applies both ambient and forced vibration surveys to investigate the dynamic properties of a six-story residential building in Istanbul. Mode shapes, modal frequencies and damping ration were determined. Later on numerical analysis with finite element method was performed. Based on the first three modes of the building, a model updating strategy was employed. The study enabled to compare the results of ambient and forced vibration surveys and check the accuracy of the numerical models used for the performance evaluation of the reinforced concrete buildings.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제9권9호
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• pp.3496-3514
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• 2015

One of the challenging tasks in Mobile Ad hoc Network is to discover precise optimal routing solution due to the infrastructure-less dynamic behavior of wireless mobile nodes. Ant Colony Optimization, a swarm Intelligence technique, inspired by the foraging behaviour of ants in colonies was used in the past research works to compute the optimal path. In this paper, we propose a Recurrent Ant Colony Optimization (RECACO) that executes the actual Ant Colony Optimization iteratively based on recurrent value in order to obtain an optimal path convergence. Each iteration involves three steps: Pheromone tracking, Pheromone renewal and Node selection based on the residual energy in the mobile nodes. The novelty of our approach is the inclusion of new pheromone updating strategy in both online step-by-step pheromone renewal mode and online delayed pheromone renewal mode with the use of newly proposed metric named ELD (Energy Load Delay) based on energy, Load balancing and end-to-end delay metrics to measure the performance. RECACO is implemented using network simulator NS2.34. The implementation results show that the proposed algorithm outperforms the existing algorithms like AODV, ACO, LBE-ARAMA in terms of Energy, Delay, Packet Delivery Ratio and Network life time.

• Smart Structures and Systems
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• 제1권3호
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• pp.235-256
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• 2005

The non-linear behaviour of electrorheological (ER) and magnetorheological (MR) dampers makes it difficult to design effective control strategies, and as a consequence a wide range of control systems have been proposed in the literature. These previous studies have not always compared the performance to equivalent passive systems, alternative control designs, or idealised active systems. As a result it is often impossible to compare the performance of different smart damper control strategies. This article provides some insight into the relative performance of two MR damper control strategies: on/off control and feedback linearisation. The performance of both strategies is benchmarked against ideal passive, semi-active and fully active damping. The study relies upon a previously developed model of an MR damper, which in this work is validated experimentally under closed-loop conditions with a broadband mechanical excitation. Two vibration isolation case studies are investigated: a single-degree-of-freedom mass-isolator, and a two-degree-of-freedom system that represents a vehicle suspension system. In both cases, a variety of broadband mechanical excitations are used and the results analysed in the frequency domain. It is shown that although on/off control is more straightforward to implement, its performance is worse than the feedback linearisation strategy, and can be extremely sensitive to the excitation conditions.