• Journal of Computing Science and Engineering
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• 제6권4호
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• pp.310-319
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• 2012

Next generation wireless receivers demand low computational complexity algorithms with high computing power in order to perform fast signal detections and error estimations. Several signal detection and estimation algorithms have been proposed for next generation wireless receivers which are primarily designed to provide reasonable performance in terms of signal to noise ratio (SNR) and bit error rate (BER). However, none of them have been chosen for direct implementation as they offer high computational complexity with relatively lower computing power. This paper presents a low-complexity power-efficient algorithm that improves the computing power and provides relatively faster signal detection for next generation wireless multiuser receivers. Measurement results of the proposed algorithm are provided and the overall system performance is indicated by BER and the computational complexity. Finally, in order to verify the low-complexity of the proposed algorithm we also present a formal mathematical proof.

• Structural Engineering and Mechanics
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• 제38권1호
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• pp.99-123
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• 2011

Brick veneer over steel stud backup wall is lighter and easier to construct compared to brick veneer over concrete masonry backup wall. However, due to the relatively low stiffness of the steel stud backup, the brick veneer tends to crack under wind load. This paper briefly introduces a new panelized brick veneer with steel frame backup wall system that is developed to potentially address this problem. The experimental study of the performance of this system under simulated wind loading is discussed in detail. The test setup details and the test specimens are introduced, results of major interests are presented, and performance of the new system is evaluated based on the test results.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2004년도 제28회 KOSCO SYMPOSIUM 논문집
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• pp.89-92
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• 2004

This work describes a model development and numerical simulation of detailed combustion mechanisms of RDX/GAP/BTIN propellants. The analysis is based on the conservation equations of mass, energy, and species concentrations for both the condensed and gas phases, and takes into account finite-rate chemical kinetics and variable thermophysical properties. The model has been applied to study the combustion wave structures and burning characteristics of RDX/GAP/BTIN propellants over a broad range of pressures. Reasonably good agreement is achieved between the calculated and measured burning rate at atmospheric pressure. But the model calculation does not result in dark zone experimentally observed.

• 농촌계획
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• 제23권2호
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• pp.67-74
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• 2017

Migration is defined as the movement of people between residential places, and represents interactions between regions. Changes in migration involve changes in both the number of migrants toward/from regions and migration patterns across regions. However, most migration studies have focused only on the change in migrants, while no empirical study captures changes in migration patterns. In this paper, I present a function using the cosine similarity to measure changes in migration patterns, and apply it to 2001-2016 migration data of Korea. The results show that the migration patterns of Korea shifted in 2007, resulting in two distinct clusters. Local areas experienced various migration pattern changes despite few changes in the number of migrants.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.245-245
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• 2006

Recent studies of single wall carbon nanotube (SWNT)/polyimide nanocomposites indicate that these materials have a potential to provide the combination of structural integrity and sensing/actuation capability. This study shows the effect of the SWNT type and concentration on the dipole orientation and piezoelectric properties of the electroactive polymide nanocomposites using a thermally stimulated current (TSC) spectroscopy. These nanocomposites exhibit very thermally stable piezoelectric properties up to $150^{\circ}C$. This presentation will highlight the dipole orientation and electroactive characteristics of the SWNT/polyimide nanocomposites and discuss their potential multifunctional aerospace applications.

• The Korean Journal of Ceramics
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• 제7권2호
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• pp.80-84
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• 2001

The anisotropic CdS platelets were synthesized in the lamellar bilayer phase region of the octylamine-water binary system. The influence of the synthesis conditions of the system components on morphology and size of the platelets was examined. Atomic force microscopy (AFM) and high-resolution transmission electron microscopy (HRTEM) studies have shown thickness and face size of the synthesized particles. Platelets with face sizes ranging from 50 to 250 nm and thickness from 10 to 30 nm have been synthesized at room temperature. In addition, HRTEM micrographs show that the synthesized platelets are poly crystal.

• 농업과학연구
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• 제38권3호
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• pp.459-464
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• 2011

A simplified model for the colloidal calcium phosphate (CCP) nanocluster was developed from an active role of phosphate in the precipitation of casein (CN)/Ca mixtures and the composition of casein micelles (CM). The possible shape of the CCP nanocluster was selected as a tetrahedron, and we estimated that 4 CN molecules were involved in crosslinking a single CCP nanocluster. Similar values were obtained for the number of CN molecules involved in stabilizing the nanocluster when the number of CNs attached onto each nanocluster surface was deduced from the composition of CM. If one phosphoserine cluster consisted of 3 phosphoserine residues, the theoretical molecular weight and volume for the nanocluster were estimated to be 4,898 g/mol and 2.88 $nm^3$, respectively. It was also shown that the position of Ca present in our model were reasonably located to accommodate the serine phosphate in CN molecule.

• 농촌계획
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• 제22권1호
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• pp.49-56
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• 2016

Throughout the economic development era of Korea, migration occurred within a spatial hierarchy, with upward flows from rural areas to urban. The concept of step migration is a typical theory to explain these upward migration flows. Recent migration data and trends, however, indicate that migration-pattern regime shows strongly opposite-direction flows, with many of the major migration flowing downward on this national-spatial hierarchy, away from urban areas. In this study, we examine the most recent structure of migration flows up and down within the national-spatial hierarchy. We define seven tiers to tabulate origin-destination migration flows from population density of local administrative districts for the period 2001-2014, and then analyze the migration patterns between the tiers over time. The results show differentiated patterns of migration within the national-spatial hierarchy over time including specific states of migrants' life cycles.

• 비파괴검사학회지
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• 제25권3호
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• pp.222-227
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• 2005

An efficient technique fur the calculation of guided wave dispersion curves in composite pipes is presented. The technique uses a forward-calculating variational calculus approach rather than the guess and iterate process required when using the more traditional partial wave superposition technique. The formulation of each method is outlined and compared. The forward-calculating formulation is used to develop finite element software for dispersion curve calculation. Finally, the technique is used to calculate dispersion curves for several structures, including an isotropic bar, two multi-layer composite bars, and a composite pipe.

• 한국안광학회지
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• 제8권1호
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• pp.73-84
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• 2003

이 논문은 검안 교육과 법률의 세계적인 현상을 연구한 것이다. 세계의 여러 지역과 한국에서 검안을 위한 전략의 방향에서 눈과 시력 관리에 제공되는 검안의 전문성에서의 영향을 논의하였다. 눈과 시력 관리의 접근과 전달을 진행시키는데 세계검안 협회의 역할을 강조한 것이다.