• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.10
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• pp.3342-3360
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• 2014

In this paper, the capacity and BER performance of downlink distributed antenna systems (DAS) with transmit antenna selection and multiple receive antennas are investigated in MIMO composite channel, where path loss, Rayleigh fading and lognormal shadowing are all considered. Based on the performance analysis, using the probability density function (PDF) of the effective SNR and numerical integrations, tightly-approximate closed-form expressions of ergodic capacity and average BER of DAS are derived, respectively. These expressions have more accuracy than the existing expressions, and can match the simulation well. Besides, the outage capacity of DAS is also analyzed, and a tightly-approximate closed-form expression of outage capacity probability is derived. Moreover, a practical iterative algorithm based on Newton's method for finding the outage capacity is proposed. To avoid iterative calculation, another approximate closed-form outage capacity is also derived by utilizing the Gaussian distribution approximation. With these theoretical expressions, the downlink capacity and BER performance of DAS can be effectively evaluated. Simulation results show that the theoretical analysis is valid, and consistent with the corresponding simulation.

• The Plant Pathology Journal
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• v.25 no.2
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• pp.157-164
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• 2009

The complete nucleotide sequences of both RNA of an isolated Barley mild mosaic virus (BaMMV) from Iksan, Korea, have been determined. RNA1 was 7273 nucleotides long and encodes for a polyprotein of 2261 amino acids, which contains the eight putative functional proteins. RNA2 was 3520 nucleotides long and encodes for a polyprotein of 894 amino acids, which contains two functional proteins. Results of multiple sequence alignment showed 92.9% similarity with Na1 isolate, followed by Sil, UK(F), Asl1, Remis M and UK(M) isolates, respectively. Comparison of the BaMMV-Iks polyproteins with the corresponding proteins of BaMMV-Na1 isolates showed 95% amino acid sequence identity. The phylogenetic analysis revealed that Iks isolate was closely related to Na1 strain and have a common origin.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2005.03a
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• pp.68-73
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• 2005

In succession of the previous works, seismo-acoustic analysis was conducted to collect ground truth events and to discriminate surface explosions from natural earthquakes in the Korean Peninsula for 2004. In this period, total 510 seismo-acoustic events corresponding to 10.8 percent of total seismic events occurred in and near the Korean Peninsula were analyzed and discriminated as artificial surface explosions. Events distribution of the seismo-acoustic events in 2004 is similar to the previous results of 1999-2003. And newly determined seismo-acoustic events were added to the surface explosions database. To extend infrasound detection capability, Korea Institute of Geoscience and Mineral Resources (KIGAM) and Southern Methodist University (SMU) installed new seismo-acoustic array (BRDAR) in Baekryoung Island last November, 2004. The array configuration and design is nearly same to previous seismo-acoustic arrays CHNAR, KSGAR, a triangular 1 km aperture. BRDAR consists of 5 short period vertical seismometers (GS-13) in seismic vaults and 13 microbarometers (Chaparral Model 2). Preliminary analysis using data collected from BRDAR shows an extension of infrasound detection capability to western part of the Korean Peninsula. Also, multiple observations of infrasound at BRDAR and other arrays gave an opportunity to localize sound source regions.

• Composites Research
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• v.27 no.6
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• pp.207-212
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• 2014

The shape optimization of composite flexbeam sections of a bearingless helicopter rotor is studied using a finite element (FE) sectional analysis integrated with an efficient evolutionary optimization algorithm called particle swarm assisted genetic algorithm (PSGA). The sectional optimization framework is developed by automating the processes for geometry and mesh generation, and the sectional analysis to compute the elastic and inertial properties. Several section shapes are explored, modeled using quadratic B-splines with control points as design variables, through a multiobjective design optimization aiming minimum torsional stiffness, lag bending stiffness, and sectional mass while maximizing the critical strength ratio. The constraints are imposed on the mass, stiffnesses, and critical strength ratio corresponding to multiple design load cases. The optimal results reveal a simpler and better feasible section with double-H shape compared to the triple-H shape of the baseline where reductions of 9.46%, 67.44% and 30% each are reported in torsional stiffness, lag bending stiffness, and sectional mass, respectively, with critical strength ratio greater than 1.5.

• Journal of Korea Society of Digital Industry and Information Management
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• v.6 no.4
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• pp.117-130
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• 2010

Paper is on defense for so-called internet crisis, the attack of DDoS (Distributed Denial of Service) which was targeted to the central government ministries, financial sector, and portal sites of chief counties including Korea on June 7th, 2009 as its start. By conducting attack with various DDoS attacking methods in the lab environment and dividing networks targeted by the attack by layers, this paper records and analyzes the chief information for attack, destination information of packets, defense policy setting, and the flow of packet attack with the subjects of the networks separated. This study suggests CFC system using multiple firewalls applying defense policy corresponding to the target layer for ultimate attack and tests it according to the result of analyzing the attack packet information and its amount, log analysis, access recording port, and MAC and IT information, etc. by layers. This article is meaningful in that it analyzes the attack by layers, establishes firewall policy for protecting each layer, and secures accurate mechanism for detect and defense.

• Computers and Concrete
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• v.1 no.2
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• pp.211-226
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• 2004

A relatively simple multiple-vertical-line-element macro model has been incorporated into a standard computer code DRAIN-2D. It was used in blind predictions of seismic response of cantilever RC walls subjected to a series of consequent earthquakes on a shaking table. The model was able to predict predominantly flexural response with relative success. It was able to predict the stiffness and the strength of the pre-cracked specimen and time-history response of the highly nonlinear wall as well as to simulate the shift of the neutral axis and corresponding varying axial force in the cantilever wall. However, failing to identify the rupture of some brittle reinforcement in the third test, the model was not able to predict post-critical, near collapse behaviour during the subsequent response to two stronger earthquakes. The analysed macro model seems to be appropriate for global analyses of complex building structures with RC structural walls subjected to moderate/strong earthquakes. However, it cannot, by definition, be used in refined research analyses monitoring local behaviour in the post critical region.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.177-180
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• 2008

Worldwide, cyst nematode(Heterodera glycines Ichinohe) is the most destructive pathogen of cultivated soybean. In the USA, current annual yield losses are estimated to be nearly a billion dollars. Crop losses are primarily reduced by the use of resistant cultivars. Nematode populations are variable and have adapted to reproduce on resistant cultivars over time because resistance primarily traces to two soybean accessions. It is important to use diverse resistance sources to develop new nematode resistant cultivars. Soybean PI 494182 is a recent introduction from Japan and found to be resistant to multiple nematode populations. It is yellow seeded and maturity group 0. We have determined inheritance of resistance in PI 494182 using $F_{2:3}$ families derived from cross PI 494182 X cv. Skylla. Skylla is a susceptible parent. Three nematode populations, races 1, 3, and 5, corresponding to HG types 2.5.7, 0, and 2.5.7 were used to bioassay 162 $F_{2:3}$ families in greenhouse experiments. Based on Chi-square tests, a two-gene model is proposed for resistance to race 1 and a three-gene model is proposed for conditioning resistance to both races 3 and 5. Correlation coefficient analysis indicated that some genes conditioning resistance to races 1, 3, and 5 are shared or closely linked with each other. These results will be useful to soybean breeders for developing soybean cultivars for broad resistance to nematodes.

• Journal of Korean Society for Geospatial Information Science
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• v.12 no.1 s.28
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• pp.55-62
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• 2004

More recently, multiple reference based RTK GPS techniques(VRS ; Virtual Reference System) are becoming increasingly important for many precise GPS applications in many countries to overcome the constrained distance limitations of standard RTK systems. The precision of the position solutions of the rover receiver is closely connected with that of the corresponding virtual reference points(VRPs). The objective of this paper is to investigate the accuracy and performance of the VRPs on the test network have been made in post mode, and the overall analysis results were presented by comparing the solutions for the VRPs from the existing GPS reference station with the true values of the coordinates used to produce the observation data. The results show the reasonable accuracies of VRPs in the network area by using the VRS concept in post mode.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.2
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• pp.265-274
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• 2014

A recent air defense missile system(ADMS) is required to have a capability to intercept super-high speed targets such as tactical ballistic missiles(TBMs) by performing engagement control efficiently. The air defense missile system should be ready to engage the TBMs as soon as the ADMS detects TBMs because falling velocity of TBM is very high and remaining time interval to engage TBM is very short. As a result, the ADMS has to predict the trajectories of TBMs accurately with estimated states of dynamics to generate predicted intercept point(PIP). In addition, it is needed to engage TBMs accurately via transmitting the obtained PIP data to the corresponding intercept missiles. In this paper, an analysis about the relationship between ballistic coefficient and PIP accuracy which is depending on geodetic height of the first detection of TBM is included and an issue about effective engagement control for the TBM is considered.

• Journal of Korean Clinical Nursing Research
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• v.25 no.3
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• pp.303-313
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• 2019

Purpose: The purpose of this study was to examine nurses' knowledge, health beliefs, and performance regarding the infection control of catheter-associated urinary tract infection (CAUTI) and to identify factors affecting their infection control performance of the CAUTI. Methods: The subjects were 166 nurses at three hospitals with less than 300 beds in urban areas.Data were collected using structured questionnaires about knowledge, health beliefs, and performance regarding the infection control of the CAUTI. Statistical analysis included t-test, ANOVA, Pearson's Correlation Coefficients, Multiple regression analysis. Results: The factors affecting the infection control performance of CAUTI were knowledge (β=.18, p=.010), perceived seriousness (β=.25, p=.001), perceived barriers (β=.41, p<.001), and cues to action (β=.15, p=.030), and these factors explained 28.7% of the variance for the infection control performance of the CAUTI. Conclusion: In this study, higher levels of knowledge, perceived seriousness and, cues to action, and lower perceived barriers resulted in a corresponding higher performance in the infection control of CAUTI. Based on these findings, providing intervention programs enhancing the health beliefs of nurses is necessary to ensure their infection control performance of the CAUTI.