• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.70-73
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• 2004

The packaging of the integrated circuits requires knowledge of ceramics and metals to accommodate the fabrication of modules that are used to construct subsystems and entire systems from extremely small components. Composite ceramics (Al$_2$O$_3$-SiO$_2$) were tested for substrates. A stress analysis was conducted for a linear work-hardening metal cylinder embedded in an infinite ceramic matrix. The bond between the metal and ceramic was established at high temperature and stresses developed during cooling to room temperature. The calculations showed that the stresses depend on the mismatch in thermal expansion, the elastic properties, and the yield strength and work hardening rate of the metal. Experimental measurements of the surface stresses have also been made on a Cu/Al$_2$O$_3$-SiO$_2$ceramic system, using an indentation technique. A comparison revealed that the calculated stresses were appreciably larger than the measured surface stresses, indicating an important difference between the bulk and surface residual stresses. However, it was also shown that porosity in the metal could plastically expand and permit substantial dilatational relaxation of the residual stresses. Conversely it was noted that pore clusters were capable of initiating ductile rupture, by means of a plastic instability, in the presence of appreciable tri-axiality. The role of ceramics for packaging of microelectronics will continue to be extremely challenging.

• The KIPS Transactions:PartD
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• v.9D no.3
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• pp.399-408
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• 2002

Component technology was proposed and applied to software development to overcome software crisis. Software component is a black box like an integrated circuit in hardware but it can not be utilized without good support specially for helping users understand efficiently. This paper shows that data book format for understanding hardware component can be well applied to representing software component. We selected an approach to understand component by matching the contents of data book with UML and API model technique. Besides, we added the architecture part and the interface which are the most important property of software component to the data book for software components. In order to verify effectiveness of components data book we extended batch descriptor in EJB and performed an experiment providing data book to programmers with components.

• Tunnel and Underground Space
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• v.6 no.3
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• pp.209-222
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• 1996

Shut-in pressure, reopenting pressure and fracture orientation are very important parameters to be evaluated precisely in in-situ stress measurement by hydraulic fracturing. Graphical methods on pressure-time curves have been conventionally used, even though these are seriously dependent on subjectivity of interpreters. So there have been many demands on new method to objectivity in determining parameters. We have developed integrated hydrofracturing data processing program (HYDFRAC), based on nonlinear regression analysis and can be invoked under the Window graphical user interface. HYDFRAC consiste of three routines, that is shut-in pressure routine, reopening pressure routine, and fracture delineation routine. Each of routines include independent modules according to parameter determination methods. Its application to field tests ensured both objectivity and facility in determining of hydraulic fracturing parameters. Determining shut-in pressures at each pressurization cycles, we adopted the exponential pressure-decay method(EPD method), the bilinear pressure-decay-rate method (PDR method), and the tangent intersection method in order to find the pressurization-cyclic tendency of shut-in pressures. The estimated pressure by PDR method exists in the range of the upper and lower values by EPD method, and lies near to the upper value more than the lower. Being the pressurization cycle increased, the range of upper and lower limits come to be stabilized gradually. By graphical superposition method and bilinear pressure-accumulated volume method, reopening pressures were determined. Vertical and inclined fracture attitudes were determined by applying the directional statistics and sinusoidal curve fitting, respectively. The results of evaluation of hydrofracturing parameters showed that statistical methods could enhance the objectivity better than graphical methods.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.192-199
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• 2001

Chemical mechanical planarization (CMP) has emerged as the planarization technique of choice in both front-end and back-end integrated circuit manufacturing. Conventional CMP process utilize a polyurethane polishing pad and liquid chemical slurry containing abrasive particles. There hale been serious problems in CMP in terms of repeatability and deflects in patterned wafers. Especial1y, dishing and erosion defects increase the resistance because they decrease the interconnection section area, and ultimately reduce the lifetime of the semiconductor. Methods to reduce dishing & erosion have recently been interface hardness of the pad, optimization of the pattern structure as dummy patterns. Dishing & erosion are initially generated an uneven pressure distribution in the materials. These defects are accelerated by free abrasives and chemical etching. Therefore, it is known that dishing & erosion can be reduced by minimizing the abrasive concentration. Minimizing the abrasive concentration by using CeO$_2$is the best solution for reducing dishing & erosion and for removal rate. This paper introduce dishing & erosion generating mechanism and a method fur developing a semi-rigid abrasive pad to minimize dishing & erosion during CMP.

• Journal of the Korean Society of Industry Convergence
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• v.22 no.6
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• pp.703-709
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• 2019

This paper proposes a monitoring and remote control system, an essential part of In Vehicle Infotainment (IVI) and Human Vehicle Interface (HVI) to provide safety and convenience to a driver. The system utilizes Bluetooth for a short range communication and utilizes WCDMA for a long range communication to enhance efficiency. In this paper, an integrated controller, which integrates a CAN communication module, a Bluetooth communication module, a WCDMA communication module, is designed to control a car. Also, a remote server for managing data is designed to provide real-time monitoring and remote control for a user via smart devices. Experiment results show that all the proposed remote control, driving log, real-time monitoring, and diagnostics functions are working properly. With the proposed system, a driver can drive safely by monitoring and inspecting a car before driving via smart devices, and control conveniently by controlling a car remotely.

• Proceedings of the Korea Information Processing Society Conference
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• 2015.10a
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• pp.740-743
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• 2015

The increasing complexity of integrated circuits and IP-based hardware designs have created the risk of hardware Trojans. This paper introduces a new type of threat, the coherence-exploiting hardware Trojan. This Trojan can be maliciously implanted in master components in a system, and continuously injects memory read transactions on to bus or main interconnect. The injected traffic forces the eviction of cache lines, taking advantage of cache coherence protocols. This type of Trojans insidiously slows down the system performance, incurring Denial-of-Service (DoS) attack. We used Xilinx Zynq-7000 device to implement and evaluate the coherence-exploiting Trojan. The malicious traffic was injected through the AXI ACP interface in Zynq-7000. Then, we collected the L2 cache eviction statistics with performance counters. The experiment results reveal the severe threats of the Trojan to the system performance.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.244-247
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• 2010

In this paper, propose for the international standards of security and reliability SEED block cipher algorithm is applied to the ICMP. This paper is improve security, reliability and user comfort of weakness existing integrated case management system on spring based java framework technology. As a result, part of the user interface to improve performance and can be applied to real world applications.

• Journal of Ocean Engineering and Technology
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• v.22 no.2
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• pp.78-84
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• 2008

As a preliminary step to build a complete superyacht hull design program, the development of superyacht profile design system is introduced. The two-dimensional hull profile is decomposed into four local zones depending upon the functionality and connecting continuity of the profile. Characteristics of each zone are investigated and used to generate the model describing the geometric shape of zone using freeform curves. A set of design parameters is derived from the established geometric model. Generation and modification of a model are is by manipulating the chosen parameters. Four zones designed are integrated to form a final profile. An interactive design system performing all the modeling and modification processes is implemented using the graphic user interface system based an Microsoft Foundation Class and OpenCASCADE, a open graphic library. The shapes of the profiles generated by the developed design system are verified with those of built superyachts. The developed design system will be used for the construction of three-dimensional superyacht hull modeling system.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.82.2-82.3
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• 2019

Korea Astronomy and Space Science Institute (KASI), in collaboration with the NASA Goddard Sparce Flight Center (GSFC), will develop a next generation coronagraph for the International Space Station (ISS). COronal Diagnostic EXperiment (CODEX) uses multiple filters to obtain simultaneous measurements of electron density, temperature, and velocity within a single instrument. CODEX's regular, systematic, comprehensive dataset will test theories of solar wind acceleration and source, as well as serve to validate and enable improvement of space-weather/operational models in the crucial source region of the solar wind. CODEX subsystems include the coronagraph, pointing system, command and data handling (C&DH) electronics, and power distribution unit. CODEX is integrated onto a standard interface which provides power and communication. All full resolution images are telemeters to the ground, where data from multiple images and sequences are co-added, spatially binned, and ratioed as needed for analysis.

• Journal of Internet Computing and Services
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• v.20 no.5
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• pp.79-86
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• 2019

This paper is an overview of key elements of Korea National Open University's smart mobile learning system, and an attempt to evaluate its main services relative to the FRAME model and the Mobile Learning Development Model for distance learning in higher education. KNOU improved its system architecture to one based on xMOOC e-learning content delivery while also upgrading its PC-based online/mobile learning services to facilitate an easier and more convenient access to lectures and for better interactivity. From the users' viewpoint, the upgraded 'U-KNOU Campus' allows for a more integrated search capability coupled with better course recommendations and a customized notification service. Using the new system, the students can access not only the school- and peer-issued messages via online bulletin boards but also share information and pose questions to others including to the school faculty/officials and system administrators. Additionally, a new mobile payment method has been incorporated into the system so that the students can select and pay for additional courses from anywhere. In spite of these advances, the issue of device usability and content development remain; specifically U-KNOU Campus needs to improve its instructor-learner and learner-to-learner interactivity and mobile evaluation interface.