• Journal of Information Science Theory and Practice
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• 제2권4호
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• pp.61-76
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• 2014

The exponential growth of information on the web far exceeds the capacity of present day information retrieval systems and search engines, making information integration on the web difficult. In order to overcome this, semantic web technologies were proposed by the World Wide Web Consortium (W3C) to achieve a higher degree of automation and precision in information retrieval systems. Semantic web, with its promise to deliver machine understanding to the traditional web, has attracted a significant amount of research from academia as well as from industries. Semantic web is an extension of the current web in which data can be shared and reused across the internet. RDF and ontology are two essential components of the semantic web architecture which support a common framework for data storage and representation of data semantics, respectively. Ontologies being the backbone of semantic web applications, it is more relevant to study various approaches in their application, usage, and integration into web services. In this article, an effort has been made to review the research work being undertaken in the area of design and development of ontology supported information systems. This paper also briefly explains the emerging semantic web technologies and standards.

• Journal of Information Science Theory and Practice
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• 제5권1호
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• pp.26-46
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• 2017

This article investigates perceptions and use of Open Access journals (OAJs) by master's degree students in two universities in the southwestern part of Nigeria. A descriptive survey design was used in the study and the study population was comprised of 7,423 master's degree students in the University of Ibadan and 1,867 from Obafemi Awolowo University. A multistage random sampling technique was used to select a sample size of 249 and the data collection instrument was a structured questionnaire. Data were analyzed using frequency counts, percentages, mean, standard deviation, correlation, and regression analyses. The findings revealed that OAJs were used for learning, dissertation writing, personal research, and development. OAJs were not frequently used because of download delays, unavailability of Internet facilities, and limited access to computers terminals, among other issues. OAJs were found to be of relative advantage, positively perceived, and found to be compatible with existing values and quality assurance in scholarly publications, hence their use for academic activities. The regression analyses showed that there was a significant positive relationship between positive perception, perception of relative advantage, perception of compatibility, perception complexity, and master's degree students' use of OAJs. Negative perception was found to have a significant negative correlation with the use of OAJs. This article recommends that quality assurance of OAJs should be ensured in order to boost users' positive perceptions to increase their patronage and usage of these scholarly outlets for various academic activities, which will in turn encourage research and development across the various institutions of higher learning in Nigeria.

• 한국정보과학회논문지:시스템및이론
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• 제26권11호
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• pp.1285-1295
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• 1999

본 논문은 방대한 크기의 볼륨 데이타를 효율적으로 렌더링하기 위한 셀 기반 웨이브릿 압축 방법을 제시한다. 이 방법은 볼륨을 작은 크기의 셀로 나누고, 셀 단위로 웨이브릿 변환을 한 다음 복원 순서에 따른 런-길이(run-length) 인코딩을 수행하여 높은 압축율과 빠른 복원을 제공한다. 또한 최근 복원 정보를 캐쉬 자료 구조에 효율적으로 저장하여 복원 시간을 단축시키고, 에러 임계치의 정규화로 비정규화된 웨이브릿 압축보다 빠른 속도로 정규화된 압축과 같은 고화질의 이미지를 생성하였다. 본 연구의 성능을 평가하기 위하여 {{}} 해상도의 볼륨 데이타를 압축하여 쉬어-？ 분해(shear-warp factorization) 알고리즘에 적용한 결과, 손상이 거의 없는 상태로 약 27:1의 압축율이 얻어졌고, 약 3초의 렌더링 시간이 걸렸다.Abstract This paper presents an efficient cell-based wavelet compression method of large volume data. Volume data is divided into individual cell of {{}} voxels, and then wavelet transform is applied to each cell. The transformed cell is run-length encoded according to the reconstruction order resulting in a fairly good compression ratio and fast reconstruction. A cache structure is used to speed up the process of reconstruction and a threshold normalization scheme is presented to produce a higher quality rendered image. We have combined our compression method with shear-warp factorization, which is an accelerated volume rendering algorithm. Experimental results show the space requirement to be about 27:1 and the rendering time to be about 3 seconds for {{}} data sets while preserving the quality of an image as like as using original data.

• ETRI Journal
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• 제24권3호
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• pp.221-225
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• 2002

We performed nonlinear transmission measurements and quantum-chemical calculations on dithienothiophene(DTT)-based molecules to gain insight into the effect of acceptor and donor groups on two-photon absorption(TPA) properties. The TPA intensity showed dispersion characteristics of the single-photon absorption spectrum. When the molecules included an asymmetric donor-acceptor pair, the single- and two-photon absorption maximum wavelengths were red-shifted more than when the molecules had a symmetric donor-donor structure. We interpreted this result as indicating that the $S_2$ state plays the dominating role in the absorption process of molecules with a symmetric structure. The experimental TPA ${\delta}$ values at the absorption peak wavelength showed a dependence on the structural variations. We found the self-consistent force-field theory and Hartree-Fock Hamiltonian with single configuration interaction formalism to be valid for evaluating TPA ${\delta}$. Although the quantum-chemical calculations slightly underestimated the experimental ${\delta}$ values obtained from nonlinear trans -mission measurements, they reasonably predicted the dependence of the ${\delta}$ value on the structural variations. We confirmed the role of molecular symmetry by observing that donor-donor substituted structure gave the highest experimental and theoretical TPA ${\delta}$ values and that the donor-acceptor substituted structure showed a greater red-shift in the TPA absorption maximum wavelength. Overall, the theoretical ${\delta}$ values of DTT-based molecules were in the order of $10^{-46}\;cm^4{\cdot}s{\cdot}photon^{-1}$ and are higher than that of AF-50 by nearly two orders of magnitude.

• Structural Engineering and Mechanics
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• 제6권2호
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• pp.143-159
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• 1998

The objective of this present work is to estimate the failure loads, associated maximum transverse displacements, locations and the modes of failure, including the onset of delamination, of thin, square symmetric laminates under the action in-plane positive (+ve) shear load. Two progressive failure analyses, one using the Hashin criterion and the other using a Tensor polynomial criterion, are used in conjunction with finite element method. First order shear deformation theory along with geometric non-linearity in the von Karman sense have been employed. Variation of failure loads and failure characteristics with five type of lay-ups and three types of boundary conditions has been investigated in detail. It is observed that the maximum difference between failure loads predieted by various criteria depends strongly on the laminate lay-up and the flexural boundary restraint. Laminates with clamped edges are found to be more susceptible to failure due to transverse shear (ensuing from the out of plane bending) and delamination, while those with simply supported edges undergo total collapse at a load slightly higher than the fiber failure load. The investigation on negative (-ve) in-plane shear load is in progress and will be communicated as part-II of the present work.

• Steel and Composite Structures
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• 제33권5호
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• pp.663-679
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• 2019

In this work, a simple four-variable trigonometric shear deformation model with undetermined integral terms to consider the influences of transverse shear deformation is applied for the dynamic analysis of anti-symmetric laminated composite and soft core sandwich plates. Unlike the existing higher order theories, the current one contains only four unknowns. The equations of motion are obtained using the principle of virtual work. The analytical solution is determined by solving the eigenvalue problem. The influences of geometric ratio, modular ratio and fibre angle are critically evaluated for different problems of laminated composite and sandwich plates. The eigenfrequencies obtained using the current theory are verified by comparing the results with those of other theories and with the exact elasticity solution, if any.

• Smart Structures and Systems
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• 제25권6호
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• pp.693-705
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• 2020

In the current investigation, large amplitude free vibration behavior of shallow curved pipes (tubes) made of functionally graded materials is investigated. Properties of the tube are distributed across the radius of the tube and are obtained by means of a power law function. It is also assumed that all thermo-mechanical properties are temperature dependent. The governing equations of the tube are obtained using a higher order shear deformation tube theory, where the traction free boundary conditions are satisfied on the top and bottom surfaces of the tube. The von Kármán type of geometrical non-linearity is included into the formulation to consider the large displacements and small strains. Uniform temperature elevation of the tube is also included into the formulation. For the case of tubes which are simply supported in flexure and axially immovable, the governing equations are solved using the two-step perturbation technique. Closed form expressions are provided to obtain the small and large amplitude fundamental natural frequencies of the FGM shallow curved tubes in thermal environment. Numerical results are given to explore the effects of thermal environment, radius ratio, and length to thickness ratio of the tube on the fundamental linear and non-linear frequencies.

• Structural Engineering and Mechanics
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• 제40권6호
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• pp.783-800
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• 2011

This paper addresses the finite strip formulations for the stability analysis of viscoelastic composite plates with variable thickness in the transverse direction, which are subjected to in-plane forces. While the finite strip method is fairly well-known in the buckling analysis, hitherto its direct application to the buckling of viscoelastic composite plates with variable thickness has not been investigated. The equations governing the stiffness and the geometry matrices of the composite plate are solved in the time domain using both the higher-order shear deformation theory and the method of effective moduli. These matrices are then assembled so that the global stiffness and geometry matrices of a moderately thick rectangular plate are formed which lead to an eigenvalue problem that is solved to determine the magnitude of critical buckling load for the viscoelastic plate. The accuracy of the proposed model is verified against the results which have been reported elsewhere whilst a comprehensive parametric study is presented to show the effects of viscoelasticity parameters, boundary conditions as well as combined bending and compression loads on the critical buckling load of thin and moderately thick viscoelastic composite plates.

• 가정과삶의질연구
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• 제17권3호
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• pp.1-16
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• 1999

This study focuses on the beginning of transition to parenthood expectation and applies the exchange theory in order to examine reward and cost of transition to parenthood expectation and picks up the main cause effecting it. This study conducted structured questionnaires to total 330 first pregnant women and examined descriptive statistics and t-test F-test analysis by using collected data. And here are the result of research. First the transition to parenthood expectation expected rewards much more than costs and had much importance on individual aspects in parenthood. The more were they aged hardly educated and housewives the higher did they showed expectation of reward. The less did they have high education the more did they expect costs of the transition to parenthood expectation. Second to examined the reward/cost of transition to parenthood expectation according to martial satisfaction the more did they have martial satisfaction the more did they expectation of the rewa ds on transition to parenthood expectation. On the contrary the more did they respect from husbands the less did they cost of transition to parenthood expectation. This study would be helpful to lead family life having childbirth to the positive way be examining the process from childbirth plan to delivery. Also it will be applicable to seek for the methods to help would-be parents as basic data on material on education about transition to parenthood.

• 대한가정학회지
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• 제39권11호
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• pp.161-174
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• 2001

In the 7th curriculum revision, Home Economics and Technology are combined into one subject, Practical Arts(Technology Home Economic), from 5th to 10th grades. The purpose of this study was to ewamine what perspectives home economics teachers and technology teachers have on curriculum. A questionnaire survey was carried out to the 297 middle school home economics teachers and technology teachers across the nation, to find out the differences of their perspectives on curriculum by independent variables. The findings of this study were as follows: 1) Both groups of home economics teachers and technology teachers supported interpretive, emancipators, and technical perspective on curriculum in the order named. 2) Teachers who have teaching experience of 21 years or more showed higher orientation toward technical perspective than those who have teaching experience of 10 years or less in assumptions on society, educational goal, Knowledge, and teaching-loaming method. 3) Public school teachers showed stronger orientation toward technical perspective in assumptions on teaching-learning method, and toward emancipatory perspective in assumptions on society. 4) Teachers who majored in or took charge of Technology generally had strong orientation toward technical perspective, whereas those who majored in or took charge of Home Economics oriented more toward interpretive or emancipatory than technical perspective.