• Journal of KIISE:Computing Practices and Letters
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• 제15권7호
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• pp.500-504
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• 2009

A reliability of software is a type of nonfunctional requirement. Traditionally, a validation of the reliability is processed at the integration phase in software development life cycle. However, it increases the cost and the risk for the development. In this paper, we propose reliability analysis method based on mathematical analytic model at the architecture design phase of the development process as follows. First, we propose the software modeling methodology for reliability analysis using Hierarchical combined Queueing Petri Nets(HQPN). Second, we derive the Markov Reward Model from the HQPN based model. We apply our approach to the video conference system to verify the usefulness of our approach. Our approach supports quantitative evaluation of the reliability.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제43권7호
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• pp.38-49
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• 2006

In this paper, a novel concept based on embedded processor and reconfigurable logic is proposed for efficient manufacturing test and design verification. Unlike traditional gap between design verification and manufacturing test, proposed concept is to combine both design verification and manufacturing test. The semiconductor chip which is using the proposed concept is named "SwToC" and SwToC stands for System with Test On a Chip. SwToC has two main features. First, it has functional verification function on a chip and this function could be made by using embedded processor, reconfigurable logic and memory. Second, it has internal ATE on a chip and this feature also could be made by the same architecture. To evaluate the proposed SwToC, we have implemented SwToC using commercial FPGA device with embedded processor. Experimental results showed that the proposed chip is possible for real application and could have faster verification time than traditional simulation method. Moreover, test could be done using low cost ATE.

• Journal of Korea Game Society
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• 제9권4호
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• pp.45-56
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• 2009

It is necessary for young children to integrate the sense of sight, hearing, touch, etc. for developing their emotion and cognition. Thanks to Information and Communication Technology (ICT) development, young children have more opportunities to use various senses in learning process. However, ICT learning method is more focusing on the sense of sight and hearing, and lacks of integrated recognition and this fact leads to the reason why ICT can not be used as a main education tool. Therefore, this study evaluated the influence of wUbi-Pen(haptic device) on cognition using a computer puzzle program. The results show that young children using a haptic pen have greater intention and performance in object assembly, mazes, picture completion in K-WPPSI test than those of non-using haptic pen. This implies that haptic function should be considered in ICT material and indeed useful in various cognition-related symptoms and diseases.

• The Transactions of the Korean Institute of Power Electronics
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• 제11권1호
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• pp.7-13
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• 2006

Linear compressors with a free piston driven by a linear motor are widely attention in the cooling apparatus such as refrigerator due to the high efficiency The stroke of piston in the linear compressor driven by LPMSM (Linear Permanent-Magnet Synchronous Motor) can be obtained from Integrating the input voltage and current of LPMSM, but it may be diverged due to dc components in the voltage and current. The strategy to prevent the divergence of stroke using both the high-pass filter and do offset compensation was suggested. The equations for the magnitude and phase of the stroke and also dc offset including the stroke are derived as a function of the cut-off frequency of HPF. The accurate stroke of a piston can be calculated by compensating for dc offset. The performance of the newly developed stroke calculation scheme has been verified by experimentally on a linear compressor drive system, where the control was implemented by a 16-bit DSP.

• Journal of Educational Research in Mathematics
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• 제16권1호
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• pp.1-23
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• 2006

It is regarded as critical to analyse and re-appreciate Euclidean geometry for the sake of improving school geometry This study, a critical analysis of demonstrative plane geometry in current secondary school mathematics with an eye to the viewpoints of 'Elements of Geometry', is conducted with this purpose in mind. Firstly, the 'Elements' is analysed in terms of its educational purpose, concrete contents and approaching method, with a review of the history of its teaching. Secondly, the 'Elemens de Geometrie' by Clairaut and the 'histo-genetic approach' in teaching geometry, mainly the one proposed by Branford, are analysed. Thirdly, the basic assumption, contents and structure of the current textbooks taught in secondary schools are analysed according to the hypothetical construction, ordering and grouping of theorems, presentations of proofs, statements of definitions and exercises. The change of the development of contents over time is also reviewed, with a focus on the proportional relations of geometric figures. Lastly, tile complementary way of integrating the two 'Elements' is explored.

• Journal of Ocean Engineering and Technology
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• 제15권3호
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• pp.120-127
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• 2001

The potential pollution problems resulting from tanker collision necessitate the requirement for an effective structural design and the development of relevant safety regulations. During a few decades, the great effort has been made by the international Maritime Organization and the Administration, etc, to reduce oil spillage from collision accidents. However there is still a need for investigation in the light of structural evaluation method for the experiments and rational analysis, and design development for an operational purpose of ships. This study aims for investigating a complicated structural response of bow structures of simplified models and oil carriers for assessing the energy dissipation and crushing mechanics of the striking vessels through a methodology of the numerical analysis for the various models and its design changes. Through these study an optimal bow construction absorbing great portion of kinetic energy at the least penetration depth prior to reach to the cargo area and an effective location of collision bulkhead are investigated. In order to obtain a rational results in this study, three stages of collision simulation procedures have been performed step by step as follows; 1) 16 simplified ship models are used to investigate the structural response against bow collision with variation of primary and secondary members. Mass and speed are also varied in four conditions. 2) 21 models consisted of 5 sizes of the full scaled oil carriers are used to perform the collision simulation with the various sizes and deadweight delivered in a recent which are complied with SOLAS and MARPOL. 3) 36 models of 100l oil carrier are used to investigate the structural response and its influence to the collision bulkhead against bow collision in variation with location of collision bulkhead, primary members, framing system and colliding conditions, etc. By the first study using simplified models the response of the bow collision is synthetically evaluated for the parameters influencing to the absorbed energy, penetration depth and impact force, etc.

• Journal of Digital Convergence
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• 제13권4호
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• pp.417-423
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• 2015

Oil-in-water(o/w) nanoemulsions were prepared in the system of water/Span 80-Tween 80/long-chain paraffin oil via PIC method. With the increase of preparation temperature from 30 oC to 80 oC, the diameter of emulsion droplets decreased from 150 nm to 40 nm. By varying the HLB of mixed surfactants, we found that there was an optimum HLB around 13.0~14.0 corresponding to the minimum droplet size. The size of emulsion droplets increased upon increasing the ratio of oil/emulsifying agent. At $f{\leq}0.15$, the size of nanoemulsions could be kept constant more than 2 months. The increase in preparation temperature makes it possible for producing monodisperse nanoemulsions. Once the nanoemulsion is produced, the stability against Ostwald ripening is outstanding due to the extremely low solubility of the liquid paraffin oil in the continuous phase.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.674-677
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• 2008

The Architecture, engineering, & construction (AEC) industry domains have grown more complex and larger, BIM is a digital representation of a building to facilitate the exchange and development of construction information integration and interoperability. Industry Foundation Classes (IFCs), under development by International Alliance for Interoperability (IAI), represent the part of buildings or elements of a process. IFC has been adopted as a central information repository in order to deliver integrated building information. Other BIM software could open the IFC file, recognize standard objects such as walls, window, and doors as building components. The IFC standard is generally agreed to be of high quality and is widely implemented in software. However, sometimes, information distortion or information toss occurrs during information exchang. The IAI Model Support Group (IAI-MSG) offers the opportunity to certify IFC-compliant applications based on a structuralized approach. However, IFC interoperability error also have occurred by using certificated tools. As project participants exchange BIM information by using BIM software they will need a reliable and efficient exchange of information. In this paper, previous interoperability tests were analyzed, and we propose a new concept in interoperability test.

• Fashion & Textile Research Journal
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• 제14권6호
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• pp.889-897
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• 2012

This study suggests a direction for stage-costume design by making stage costumes based on amusement, eclecticism, and the masquerade, which are the criteria for approaching stage costume designs according to characteristics of the mask theatre presented by P. G. Bogatyryov. The conclusions of this study are as follows. First, criteria to approach stage costume design for mask theatre can be classified into amusement, eclecticism, and masquerade according to the characteristics of the mask theatre presented by P. G. Bogatyryov. Second, the stage costume of a mongrel dog showed amusement through the expression of the image of therianthropy through the combination of a fur-lined vest and wristlet, Korean traditional trousers with the paw-prints of a dog. Third, eclecticism contains diverse characteristics and escapes from being singularly defined due to the fusion of severally different heterogeneous objects. The stage costume differently used a method of wearing clothing in a different period, of choosing clothing materials, and of expressing color in every character to indicate ambiguity to which the drama points through the integration of various expression elements. Fourth, the masquerade present characters (Taembang, Daejang, and Changseok)who simultaneously play the role of fairies after having changed into a white mask and having worn Korean a traditional overcoat (Durumagi) on the original clothes; the, result is the change of the theatrical structure into another time and space inside the theatrical scene of imagination through a concealment of the original clothing.

• Transactions of the Korean Society of Mechanical Engineers B
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• 제37권4호
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• pp.323-329
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• 2013

This study attempts to simulate the structure of a woody leaf netted venation system by using topology optimization techniques. Based on finite element method (FEM) analysis of an incompressible fluid, a topology optimal design is applied to those woody leaf netted venation models. To solve the transverse shear locking problem of a thin plate caused by the Mindlin-Reissner plate model where a leaf netted venation is assumed to be a thin plate, a P1-nonconforming element and selective reduced integration are employed. Topology optimal design is applied to multiple physical domains. Combined with the Darcy-Stokes flow problems and extended to the optimal design of fluid channels, the multiple physical models of the flow system are analyzed and venation patterns of leafs are simulated. The calculated optimal shapes are compared with the natural shapes of woody leaf venation patterns. This interdisciplinary approach may improve our understanding of the leaf venation system.