• Advances in aircraft and spacecraft science
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• 제10권3호
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• pp.281-302
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• 2023

In this paper, bending analysis of exponentially varying functionally graded (FG) plate is presented using trigonometric shear deformation theory (TSDT) considering both transverse shear and normal deformation effects. The in-plane displacement field consists of sinusoidal functions in thickness direction to include transverse shear strains and transverse displacement include the effect of transverse normal strain using the cosine function in thickness coordinate. The governing equations and boundary conditions of the theory are derived using the virtual work principle. System of governing equations, for simply supported conditions, Navier's solution technique is used to obtain results. Plate material properties vary across thickness direction according to exponential distribution law. In the current theory, transverse shear stresses are distributed accurately through the plate thickness, hence obviates the need for a shear correction factor. TSDT results are compared with those from other theories to ensure the accuracy and effectiveness of the present theory. The current theory is in excellent agreement with the semi-analytical theory.

• 신재생에너지
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• 제1권3호
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• pp.35-41
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• 2005

This paper analyses the economics of grid-connected photovoltaic systems. With the 2003 cost of photovoltaic systems, under prevailing capital market conditions, with a system lifetime of 30 years, and under the best climatic conditions, it appears that the cost of production of grid-connected electricity could be of 0.21 US $/kWh, and under medium climatic conditions, European locations, Switzerland, Japan and South Korean could be of 0.28$/kWh. If the lifetime if the system goes up, due to future technological improvements, to a very large value such as 50 years, these costs can be lowered by 10-20%. Competitiveness of grid-connected photovoltaic electricity, while it still cannot be taken for granted, is a possibility, especially if major technological advances further lowers the costs of photo cells and increases their lifetimes.

• 한국정보시스템학회지:정보시스템연구
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• 제14권1호
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• pp.149-169
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• 2005

The purpose of this study is to investigate as individuals how and why to accept web storage service. Using the Technology Adoption Model2 (TAM2) as methodological framework, this research tries to experiment an empirical background on the acceptance of behavioral changes of an individual sa to information technological advances. The findings of this study are different from TAM2 in terms of job relevance and output quality. However, according to other elements of TAM2 such as result demonstrability, subjective norm, image, this srudy also confirms positive relationships toward technological acceptance. Especially, subjective norms shows the strongest influential factors when adopting technological changes.

• 기술혁신연구
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• 제18권2호
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• pp.147-174
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• 2010

본 연구에서는 산업의 혁신패턴이 기술체제에 좌우된다는 산업별 혁신체제론적 접근에 따라 산업의 기술체제 특성이 지식전파와 혁신성과에 미치는 영향을 분석하였다. 과학기술정책연구원의 "2008년 기술혁신활동조사: 제조업"DB 자료를 이용하여 기술체제에 따라 산업을 분류하고 계량모형을 이용해 지식외부성의 원천과 지식전파가 유발하는 기술혁신을 산업별로 분석하였는데, 주요결과는 다음과 같다. 첫째 특수적 암묵적 지식기반 산업에서는 일반적 명목적 지식기반 산업과 달리 기업의 혁신성과가 입지특성으로부터 영향을 받는 것으로 나타났으며, 고기술-특수적 암묵적 지식기반 산업에서는 연구개발자본이 풍부한 지역, 저기술-특수적 암묵적 지식기반 산업에서는 동종산업의 집적도가 높은 지역에 입지한 기업일수록 제품혁신이 활발하였다. 둘째 제품혁신을 선도적 혁신과 추종적 혁신으로 구분하여 지식전파가 유발하는 혁신수준을 산업별로 알아보았는데, 저기술산업에서는 외부로부터 전파된 지식이 선도적 혁신과 추종적 혁신을 유발하고 고기술산업에서는 추종적 혁신만 유발하는 것으로 나타났다. 이와 같은 분석결과로부터 지식외부성의 원천과 지식전파가 유발하는 기술혁신의 수준은 산업의 기술체제에 따라 다르며, 지역산업 클러스터정책은 산업의 기술체제 특성을 감안해 모색할 필요가 있다는 함의를 얻고 있다.

• 한국안전학회지
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• 제29권1호
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• pp.80-85
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• 2014

A survey of risk perception in South Korea was conducted in 2007 to evaluate relative riskiness of typical industrial and technological risks. This article summarizes the characteristics of risk perception using psychometric analyses. The survey with a sample size of 1,194 reviews the perceived level of 25 risk items in the areas of transportation, chemicals, environment, industry, nuclear power generation, and newly-introduced risks. Six categories of risk identified by a factor analysis show that the level of perceived risk does not correspond to the statistical level. Psychometric analyses including voluntariness, severity, effect manifestation, exposure pattern, controllability, familiarity, benefit and necessity demonstrate that voluntary, familiar and immediate risks are perceived as less risky than involuntary, unfamiliar and delayed ones. Risk communication is critical in reducing the discrepance between objective and subjective level of risk. However, the amount of risk information does not always justify a successful risk communication. A safety policy, risk communication strategy in particular, should take into account diverse dimensions of risk reviewed by psychometric analyses in the study. Social policy toward safety can be improved by integrating policy, human, and social factors as well as technological advances.

• Advances in materials Research
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• 제6권2호
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• pp.169-184
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• 2017

Electro-Discharge machining (EDM) is a thermal process comprising a complex metal removal mechanism. This method works by forming of a plasma channel between the tool and the workpiece electrodes leading to the melting and evaporation of the material to be removed. EDM is considered especially suitable for machining complex contours with high accuracy, as well as for materials that are not amenable to conventional removal methods. However, several phenomena can arise and adversely affect the surface integrity of EDMed workpieces. These have to be taken into account and studied in order to optimize the process. Recently, artificial neural networks (ANN) have emerged as a novel modeling technique that can provide reliable results and readily, be integrated into several technological areas. In this paper, we use an ANN, namely, the multi-layer perceptron and the back propagation network (BPNN) to predict the mean surface roughness of electro-discharge machined surfaces. The comparison of the derived results with experimental findings demonstrates the promising potential of using back propagation neural networks (BPNNs) for getting a reliable and robust approximation of the Surface Roughness of Electro-discharge Machined Components.

• 대한핵의학회지
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• 제39권6호
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• pp.407-412
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• 2005

Echocardiography is one of the most frequently used techniques for diagnosing cardiovascular diseases. Over the last twenty years, technological advances have enabled the application of high-quality imaging. Important recent developments have occurred in echocardiography that are already being used clinically. Equipment and hardware is now available to produce reai time three-dimensional and contrast enhanced imaging.. Tissue Doppler and stress echocardiography have provided potential benefit to analyze hemodynamic information of heart. This review discusses each of these new developments and their potential impact on the practice of echocardioaraphy and cardiology in general.

• 한국감성과학회:학술대회논문집
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• 한국감성과학회 1998년도 춘계학술발표 논문집
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• pp.304-308
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• 1998

Technical advances in computer networks and the Internet bring a new communication era and provide effective solutions for cooperative works and research. These technological advances introduced the concept of cyberspace that many people involve reseach and a project at different locations at the same time. In this paper, we present a fast and effective interaction protocol that is aeapted to the COLAB(COIIaborative LABoratory) Systems which use a high-speed ATM Network. The CCOLAB systems is developed for researchers those who are doing a large project on the collaborative research environment. The interaction protocol that we developed supports multi-session and multi-channel on the TCP/IP Network and provides more flexible solution to control multimedia data on the network.

• Journal of Korean Neurosurgical Society
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• 제43권2호
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• pp.69-78
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• 2008

Recently, due to the evolution of technology, the field of neurosurgery is receiving spotlight. In particular endovascular neurosurgery has gained a great interest along with the advancement of the modern neurosurgery. The most remarkable advances were made in embolization of the cerebral aneurysms, arteriovenous malformations and intracranial stenosis during the past 10 years. These advances will further change the role of neurosurgeons in treating cerebrovascular disease. Because interventional neuroradiologists have performed most of procedures in the past, neurosurgeons have been deprived of chances to learn endovascular procedure. This article discusses the development of technological aspect of endovascular neurosurgery in chronological order. By understanding the history and current status of the endovascular surgery, the future of neurosurgery will be promising.

• Clinical Endoscopy
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• 제55권5호
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• pp.594-604
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• 2022

Over the past decade, technological advances in deep learning have led to the introduction of artificial intelligence (AI) in medical imaging. The most commonly used structure in image recognition is the convolutional neural network, which mimics the action of the human visual cortex. The applications of AI in gastrointestinal endoscopy are diverse. Computer-aided diagnosis has achieved remarkable outcomes with recent improvements in machine-learning techniques and advances in computer performance. Despite some hurdles, the implementation of AI-assisted clinical practice is expected to aid endoscopists in real-time decision-making. In this summary, we reviewed state-of-the-art AI in the field of gastrointestinal endoscopy and offered a practical guide for building a learning image dataset for algorithm development.