• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2004.09a
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• pp.211-219
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• 2004

A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces stric시y related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials. In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.

• Journal of information and communication convergence engineering
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• v.7 no.2
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• pp.203-208
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• 2009

Recently, improved capabilities of the mobile device is represented in a demand for same level services with the desktop device services but the service that is developed for desktop device is not compatible with mobile devices. To fulfill these demands, it is needed to provide services with considering features of mobile devices. This means that CP(Contents Provider) must do contents transformation in order to make suitable contents on mobile device. For managing some information that is required to do contents transformation, we need the DDR(Device Description Repository) which can store and search a variety of device information to grasp the constraints on the mobile device as compared with desktop devices. Also, defining standard API is required to offer a service regardless of platforms. Hereupon W3C(World Wide Web Consortium) introduced DDR Simple API. However that specifies the limited functions of DDR, which is inevitable to be added for more precise search services. In this paper, we expanded DDR Simple API and implemented DDR that supports DDL(Device Description Language) conversion and storing and searching device information.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.8
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• pp.166-176
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• 1995

This paper presents a new high-level synthesizer for ASIC designs using ASIC library or FPGAs. DAMUL defines the VHDL description for a specified hardware and allocate some VHDL codes, which describe the behavioral specification, to the corresponding hardware before the synthesis. The interconnections are implemented by the multiplexers, and the objective of allocation is the minimization of the number of multiplexers. Also, the dedicated registers is used for global variables, in order to implement the other necessary registers as well as status and control registers. The effectiveness of the proposed system is shown by the synthesis results of benchmark circuits.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.4
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• pp.34-42
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• 1996

Robot programming has been discussed in detail during the recent years. Numerous studies in particular presented relevance, solution concepts and implementation of off-line programming. In this paper a new user-friendly robot programming method is introduced, which permits the implicit description and programming of assembly process. On the functional level of programming, the assembly processes are described in terms of their operational functions. On the language level, the individual functions are then translated into commands for the robots.

• Proceedings of the Korean Institute of Communication Sciences Conference
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• 2004.11a
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• pp.230-230
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• 2004

• Journal of Digital Contents Society
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• v.2 no.2
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• pp.167-178
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• 2001

For high performance Grid environments, an effective GIS(Grid Information System) should be adopted. In the design of GIS architecture, its grid resource information model provides a key basis. This paper presents our study on the exploration of a high performance grid resource information model. According the exploration, we identified the followings. The resource information model should clearly address the issues of relation descriptions as well as resource descriptions, issues related to scheduling support, the issue of decoupling the expression model of resource information from data repository models, and finally the issue of decoupling user-level resource descriptions from system-level resource descriptions. Based on the proposed conceptual organization of resource information models, analysis result for the existing resource information models are presented.

• Proceedings of the IEEK Conference
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• 2000.11b
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• pp.188-191
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• 2000

This paper presents a register scheduling and allocation algorithm for high level synthesis. The proposed algorithm executes the low power scheduling to reduce the switching activity using shut down technique which was not unnecessary the calculation through the extraction DFG from VHDL description. Also, the register allocation algorithm determines the minimum register after the life time analysis of all variable. It is minimum the switching activity using graph coloring technique for low power consumption. The proposed algorithm proves the effect through various filter benchmark to adopt a new scheduling and allocation algorithm considering the low power.

• Nuclear Engineering and Technology
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• v.54 no.8
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• pp.2771-2782
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• 2022

When assessing the radiological consequences of postulated accident scenarios, it is of primary interest to determine the amount of radioactive fission gas accumulated in the fuel rod free volume. The state-of-the-art semi-empirical approach (ANS 5.4-2010) is reviewed and compared with a mechanistic approach to evaluate the release of radioactive fission gases. At the intra-granular level, the diffusion-decay equation is handled by a spectral diffusion algorithm. At the inter-granular level, a mechanistic description of the grain boundary is considered: bubble growth and coalescence are treated as interrelated phenomena, resulting in the grain-boundary venting as the onset for the release from the fuel pellets. The outcome is a kinetic description of the release of radioactive fission gases, of interest when assessing normal and off-normal conditions. We implement the model in SCIANTIX and reproduce the release of short-lived fission gases, during the CONTACT 1 experiments. The results show a satisfactory agreement with the measurement and with the state-of-the-art methodology, demonstrating the model soundness. A second work will follow, providing integral fuel rod analysis by coupling the code SCIANTIX with the thermo-mechanical code TRANSURANUS.

• Journal of Broadcast Engineering
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• v.5 no.1
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• pp.82-93
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• 2000

Recently, the capability of efficient access to the desired video content is of growing importance because more digital video data are available at an increasing rate. A video summary abstracting the gist from the entirety enables the efficient browsing as well as the fast skimming of the video contents. In this paper, we discuss a novel dynamic summarization method based on the detection of highlights which represent semantically significant content and the description scheme (DS) proposed to MPEG-7 aiming to provide summary description. The summary DS proposed to MPEG-7 allows for efficient navigation and browsing to the contents of interest through the functionalities of multi-level highlights, hierarchical browsing and user-customized summarization. In this paper, we also show the validation and the usefulness of the methodology for dynamic summarization and the summary DS in real applications with soccer video sequences.

• Applied Microscopy
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• v.34 no.4
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• pp.271-276
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• 2004

The genus of Biscogniauxia, well known wood degrading fungi, is a member of the Xylariales, which has woody to carbonaceous, brown to dark brown stromata. Daldinia concentrica and Biscogniauxia sp. isolated from heavily decayed hardwood, are precisely described under light microscopic and scanning electron microscopic level. Daldinia concentrica will be the first ultrastructural description in Korea. The unidentified species collected, having small size of ascospores $11.4\;15.6{\times}9.6\;12.0{\mu}m$ with full germ slit, are taxono-mically compared with similar species found in Korea.