• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.525-530
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• 2008

There are a few core technologies to enable high-performance $4^{th}$ generation (4G) broadband wireless communication system. A multiple input multiple output (MIMO) provides high-rate transmission through expended channels by multiple array antennas in both sender and receiver side. Also orthogonal frequency division multiplexing (OFDM) is well-known as the most appropriate technique for high data rate transmission such as Mobile WiMAX and WLAN. Efficient decrease of inter-carrier interference (ISI) and inter-carrier interference (ICI) are the reasons for why OFDM is suitable for high-performance transmission, 4G mobile communication. In this paper, we mainly focus on two of objects, combination between MIMO and OFDM, and OFDM channel simulator using Ray-tracing algorithm. The results of this paper can be used implementation of a Wireless Software Platform for 4G Mobile Communication Systems.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.244-250
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• 1999

Active vibration control method for the reduction of vibration of structures have been developed. For the application of real structures active control system that has robustness must be designed because the mathematical model incompletely described has intrinsically modeling error. In this research we propose LQG/LTR method in designing control system with robustness. A combination of acceleration feedback and model-order reduction technique is used for the application of real structures and the computation efficiency. In case of such structures as the building and the tower the inter-story relative displacements represent an important constraint in seismic design. Therefore selection method of design parameters is also proposed in order to reduce the inter-story relative displacements.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2004.05a
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• pp.96-99
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• 2004

The combination of mechano-chemical activation and Self-propagating High-temperature Synthesis (SHS) has widened the possibilities for both methods. For YBCO systems the investigation showed that a short-term mechano-chemical activation of initial powders before SHS leads to single-phase and ultra-fine products. A new technique for preparation ultra-fine high-temperature superconductors of YBCO composition with a grain size d ＜1 ${\mu}{\textrm}{m}$ is developed. The specific feature of the technique is formation of the YBa$_2$Cu$_3$O$_{7-{\delta}}$ crystalline lattice directly from an X-ray amorphous state arising as a result of mechanical activation of the original oxide mixture. The technique allows the stage of formation of any intermediate reaction products to be ruled out. X-ray and magnetic studies of ultra-fine high temperature superconductors (HTS) are carried out. Dimension effects associated with the microstructure peculiarities are revealed. A considerable enhancement of inter-grain critical currents is found to take place in the ultra-fine samples.fine samples.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.1
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• pp.59-74
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• 2013

Post-modern society leads us to accept diversity and variability instead of pursuit of the absolute truth, beauty or classical value systems, thus leading to hybrid phenomena. The purpose of this study is to analyze characteristics and expressive effects of hybrid expressions through which to provide conceptual bases for interpreting expanded meanings of fashion illustrations that express aesthetic concepts of hybrid culture. Hybrid refers to a condition on which diverse elements are mixed with each other, so any one element can not dominate others. It is often used to create something unique and new by a combination of unprecedented things. Hybrid can be classified into four categories: temporal hybrid, spatial hybrid, morphological hybrid and hybrid of different genres. Temporal hybrid from a combination of past and present in fashion illustration includes temporal blending by repetition and juxtaposition. Spatial hybrid shows itself in the form of inter-penetration and interrelationship by means of projection, overlapping, juxtaposition and multiple space. Morphological hybrid expresses itself through combination of heterogenous forms and restructuring of deformed forms. Hybrid of different genres in fashion illustration applies various graphic elements or photos within the space, and represents blending of arts and daily living. Such hybrid expressions in fashion illustrations reflect the phenomena of diversity and variability of post-modern society. Hybrid expressions in fashion illustrations predict endless possibility of expressing new images through combining various forms or casual elements and can develop toward a new creative technique.

• Structural Engineering and Mechanics
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• v.82 no.5
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• pp.667-678
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• 2022

Moment-resisting frames (MRFs) are among the most conventional steel structures for mid-rise buildings in many earthquake-prone cities. Here, a simplified performance-based methodology is proposed for the seismic collapse capacity assessment of these buildings. This method employs a novel multi-mode pushover analysis to determine the engineering demand parameters (EDPs) of the regular steel MRFs up to the collapse prevention (CP) performance level. The modal combination coefficients used in the proposed pushover analysis, are obtained from two metaheuristic optimization algorithms and a fitting procedure. The design variables for the optimization process are the inter-story drift ratio profiles resulting from the multi-mode pushover analyses, and the objective values are the outcomes of the incremental dynamic analysis (IDA). Here, the collapse capacity of the structures is assessed in three to five steps, using a modified IDA procedure. A series of regular mid-rise steel MRFs are selected and analyzed to calculate the modal combination coefficients and to validate the proposed approach. The new methodology is verified against the current existing approaches. This comparison shows that the suggested method more accurately evaluates the EDPs and the collapse capacity of the regular MRFs in a robust and easy to implement way.

• Journal of KIISE:Computing Practices and Letters
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• v.10 no.4
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• pp.299-308
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• 2004

In this paper, we propose a probabilistic framework to predict the interaction probability of proteins. The notion of domain combination and domain combination pair is newly introduced and the prediction model in the framework takes domain combination pair as a basic unit of protein interactions to overcome the limitations of the conventional domain pair based prediction systems. The framework largely consists of prediction preparation and service stages. In the prediction preparation stage, two appearance probability matrices, which hold information on appearance frequencies of domain combination pairs in the interacting and non-interacting sets of protein pairs, are constructed. Based on the appearance probability matrix, a probability equation is devised. The equation maps a protein pair to a real number in the range of 0 to 1. Two distributions of interacting and non-interacting set of protein pairs are obtained using the equation. In the prediction service stage, the interaction probability of a Protein pair is predicted using the distributions and the equation. The validity of the prediction model is evaluated for the interacting set of protein pairs in Yeast organism and artificially generated non-interacting set of protein pairs. When 80% of the set of interacting protein pairs in DIP database are used as teaming set of interacting protein pairs, very high sensitivity(86%) and specificity(56%) are achieved within our framework.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.7 s.124
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• pp.638-648
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• 2007

A principal components analysis of the entire median HRIRs in the CIPIC HRTF database reveals that the individual HRIRs can be adequately reconstructed by a linear combination of several orthonormal basis functions. The basis functions represent the inter-individual and inter-elevation variations in median HRIRs. There exist elevation-dependent tendencies in the weights of basis functions, and the basis functions can be ordered according to the magnitude of standard deviation of the weights at each elevation. We propose a HRIR customization method via tuning of the weights of 3 dominant basis functions corresponding to the 3 largest standard deviations at each elevation. Subjective listening test results show that both front-back reversal and vertical perception can be improved with the customized HRIRs.

• Clinical and Experimental Pediatrics
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• v.48 no.5
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• pp.476-480
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• 2005

Immunosuppressive therapy in pediatric renal transplant recipients is changing consequence of the increasing number of available immunosuppressive agents. The optimal use of immunosuppressive agents requires a thorough understanding of the pharmacokinetic characteristics, but the information on the pharmacokinetic characteristics of these drugs in pediatric transplant recipients is still limited. In general, patients younger than 5 years old show higher clearance rates, therefore the need for higher dosages in younger patients seems evident. By the therapeutic drug monitoring, trough($C_{min}$) and peak level($C_{max}$) are measured and the area under the blood concentration-time curve(AUC), which is taken as being representative of total systemic exposure can be calculated. Cyclosporine A (CSA) has poor bioavailability, which contributes to high inter- and intra-patient pharmacokinetic variability. CSA concentration measured 2 hours after administration($C_2$) has better correlation with the AUC than $C_{min}$ and is an alternative technique that predicts the AUC. Tacrolimus(Tac) has a great deal of inter-individual variability like CSA but intra-individual variability in systemic exposure is considered to be low. Both CSA and Tac are metabolized by a cytochrome P-450 enzyme isoform(CYP3A4). We should consider changing the dosages when CSA or Tac is used in combination with the medicines that inhibit or induce the CYP3A4. In case of steroid-free immunosuppressive therapy, the blood concentration of Tac should be frequently checked and dosage adjustment may be needed.

• Journal of Korean Society of Water and Wastewater
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• v.21 no.5
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• pp.609-619
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• 2007

The objective of this paper is to evaluate the feasibility of conjunctive Operation between Multi-regional water supply networks from multiple source as a effective way to meet two conditions: to minimize the electric cost for providing water demanded and meet the water flow rate for satisfying customers. EPAnet Model is used to calculate a hydraulic water distribution condition based on an integrated operation of water supply systems located in short distance. The modeling was conducted on several simulation cases including the individual operation by existing inter-regional water supply networks within short distance, the conjunctive operation of more than two existing networks with valve fully closed and full open constraint. As a study distribution system, water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. It was found that a well-allocated water supply scheme based on a conjunctive operation promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. The result such as unit district costs, pareto optimum pump combination sets will be applied to the optimization for a conjunctive operation of existing inter-regional water supply networks within short distance.

• Journal of Korea Foundry Society
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• v.23 no.5
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• pp.244-250
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• 2003

The aim of this study is fabricating of composite filler metal (CFM) by a combination of selective laser sintering (SLS) of stainless steel powders (RapidSteel $2.0^{TM}$ and liquid phase infiltration of Ag-28 wt.%Cu alloy. Porous stainless steel body with inter-connected pore channels was fabricated by SLS, binder decomposing and densification processes. By the direct contact infiltration, the narrow inter-particle channels of the porous body were completely filled with the Ag-28 wt.%Cu alloy infiltrant. During infiltration, the dissolved elements of Fe, Ni and Cr from the porous body were solved into copper solid solution phases, which consist of eutectic structure of composite metal matrix. The S10C/CFM/S10C joints, which have narrow clearance gaps between them up to 10 micrometers, were joined successfully by self-feeding of filler metal from the matrix of CFM. The CFM kept its original thickness and microstructure after brazing. The tensile strength of brazed specimen was higher than 30 kgf/$mm^2$ and showed a typical ductile fracture mode in the CFM.