• Journal of Korean Neurosurgical Society
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• v.61 no.1
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• pp.66-74
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• 2018

Objective : The aim of this study was to identify the susceptibility genes responsible for lumbar spondylosis (LS) in Korean patients. Methods : Data from 1427 subjects were made available for radiographic grading and genome wide association studies (GWAS) analysis. Lateral lumbar spine radiographs were obtained and the various degrees of degenerative change were semi-quantitatively scored. A pilot GWAS was performed using the AffymetrixGenome-Wide Human single-nucleotide polymorphisms (SNPs), 500K array. A total of 352228 SNPs were analyzed and the association between the SNPs and case-control status was analyzed by stepwise logistic regression analyses. Results : The top 100 SNPs with a cutoff p-value of less than $3.7{\times}10^{-4}$ were selected for joint space narrowing, while a cutoff p-value of $6.0{\times}10^{-4}$ was applied to osteophytes and the Kellgren-Lawrence (K-L) osteoarthritis grade. The SNPs with the strongest effect on disc space narrowing, osteophytes, and K-L grade were serine incorporator 1 (rs155467, odds ratio [OR]=17.58, $p=1.6{\times}10^{-4}$), stromal interaction molecule 2 (STIM1, rs210781, OR=5.53, $p=5{\times}10^{-4}$), and transient receptor potential cation channel, subfamily C (rs11224760, OR=3.99, $p=4.8{\times}10^{-4}$), respectively. Leucine-rich repeat-containing G protein-coupled receptor 4 was significantly associated with both disc space narrowing and osteophytes (rs1979400, OR=2.01, $p=1.1{\times}10^{-4}$ for disc space narrowing, OR=1.79, $p=3{\times}10^{-4}$ for osteophytes), while zinc finger and BTB domain containing 7C was significantly and negatively associated with both osteophytes and a K-L grade >2 (rs12457004,OR=0.25, $p=5.8{\times}10^{-4}$ and OR=0.27, $p=5.3{\times}10^{-4}$, respectively). Conclusion : We identified SNPs that potentially contribute to the pathogenesis of LS. This is the first report of a GWAS in an Asian population.

• Journal of Advanced Navigation Technology
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• v.15 no.6
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• pp.946-952
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• 2011

In term of inaccuracy of information and increasing channel occupancy time, the use of voice communication in Air Traffic Control has many problems. In order to improve it, ICAO proposed digital communication and ADS-B system that is more effective for voice communication in ATC. For improvement of effectiveness to add additional parameter to designated ADS-B In-Out data group, many studies being performed. In this paper, we analysis voice communication for reduce the communication traffic in ATC and simulate to add aiming altitude parameter for comparative effect analysis of communication traffic between pilot and controller. The result of the analysis were successfully validated that reduction of communication traffic in ADS-B environments.

• Journal of Environmental Health Sciences
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• v.27 no.4
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• pp.15-24
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• 2001

The objective of this study it to evaluate the microbial safety in rapid sand filters adapted in most drinking water treatment plants. The potential pathogens to cause water quality problems Are presumed to be Giardia and Gryptosporidium. They look like particles in view of their size. It has been reported that if the number of particles (larger than 2 ${\mu}{\textrm}{m}$ in water) is less than 100 per mL and its turbidity is below 0.1 NTU, it is considered as a safe water in terms of pathogens. In order to achieve such a good water quality. filter-aids (chemicals) were added to the inlet-channel of filter and their effectiveness was evaluated on the basis of water quality factors such as turbidity and particle counting. This study was conducted in she three steps of experiment: jar test. pilot plant test and real water treatment plant test (P plant in seoul). The experiment reult of the P water treatment showed that cationic polyamine was the most effective in the removal of particles and turbidity at the does of 0.25 mg/L. The turbidity without filer-aids showed in the range of 0.12 ~0.17 NTU during filtration and 0.14 NTU on the average. However. with addition of polyamine, the turbidity represented below(or less than) 0.1 NTU after 20 min in the start of filtration and kept 0.08 NTU on the average. On the other hand, as for number of particles, while no filter-aids led to the range of 111 ~270 per mL and 190 on the average, addition of polydmine led to 113 per mL on talc average, and kept below100 per mL after 20 min in the start of filtration.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.4
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• pp.1-7
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• 2009

In this paper, the author presents the MIMO(Multi-Input Multi-Output) receiver algorithm with the capability of inter-cell or inter-sector interference cancellation over multi-antenna OFDM(Orthogonal Frequency Division Multiplexing) systems. As contrast with the previous research dealing with the filtering scheme at the time domain, the proposed algorithm is presented as the pre-filtering scheme which can be applicable to the frequency domain. Note that the proposed one can be implemented only by pilot symbols which are used in the channel estimation. In addition, it is analytically confirmed that the proposed scheme can be applied for either MIMO( C-SM(Collaborative-Spatial Multiplexing)) interference or SIMO(Single-Input Multi-Out) interference. The proposed receiver algorithm is verified by simulations over UL-PUSC SR off in IEEE 802.16e standard. From simulation results, it is confirmed that the proposed one can be applicable regardless of the kind of interference. Furthermore, it is verified that the performance is guaranteed even under Ole severe effect of interference and the improvement of system throughput is guaranteed.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.5
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• pp.451-460
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• 2004

The pilot bit pattern of W-CDMA system is used for the channel estimation and frame synchronization confirmation. This paper proposes the binary sequences for the frame synchronization for wideband code division multiple access (W-CDMA) system. We present the circuit for the generation of ideal frame synchronization property using the binary sequences called frame synchronization word(FSW). W-CDMA system uses compressed mode where up to 7 slots per one 10 msec frame are not transmitted to make measurements from another frequency without a full dual receiver terminal. It is shown that the proposed frame synchronization words also maintain the optimal frame synchronization property in the compressed mode by using the complementary mapping relationship of preferred pair. And we discuss the realization circuit for the generation of frame synchronization words by using the concept of preferred pairs, complementary mapping relationship, and maximal length sequence.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.11A
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• pp.1004-1011
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• 2005

In OFDM (Orthogonal Frequency Division Multiplexing) system, sampling frequency offset causes performance degradation due to increase of ICI. Sampling frequency offset can be generally estimated by correlation of the pilot signal or the known pattern within two contiguous OFDM symbol however, this method has the throughput degradation and the difficulty in applying to various OFDM systems. In this paper, we propose a new algorithm for sampling frequency offset estimation which can solve aforementioned issues. The proposed algorithm uses a single OFDM symbol to prevent throughput degradation and to apply to various OFDM-based communication systems flexibly Also, the proposed algorithm can enhance reliability by observing more number of correlations compared to the established algorithm in frequency domain. Extensive computer simulation shows that the proposed algorithm can improve the system performance in various channel conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.23 no.4
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• pp.914-925
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• 1998

This paper considers the evaluation of the hybrid acquistion perdformance for the pilot signal in the direct sequence code division multiple access(DS/CDMA) forward link. the hybrid acquisition is introduced by the combination of two schemes, the parallel and serial acquisions. The mean acquisition time of the proposed scheme is derived to consider both the best case(the correct code-phase offsets are included i one subset) and the worst case(the correct code-phase offsets exist at the boundary of two subsets), which are cause by the distribution of the correct code-phase offsets in the subset. Expressions for the detection, false alarm, and miss probabilities are derived for the case of multiple correct code-phase offsets and multipath Rayleigh fading channel. Numerical results present the hybrid acquistion performance with repect to design parameters such as postdetectio integration length in the search and verification modes, subset size, and number of I/Q noncoherent correlators, and compare the hybrid acquistion with the parallel acquistion in terms of the minimum acquistion time under the same hardware complexity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10A
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• pp.1563-1570
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• 1999

This paper relates to the soft decision method with erasure technique in digital terrestrial television broadcasting system. The proposed decoder use the CSI derived from using the pilots in receiver. The active real(I) and imaginary(Q) data are transferred to the branch metric calculation block that decides the Euclidean distance for the soft decision decoding and also the estimated CSI values are transferred to the same block. After calculating the Euclidean distance for the soft decision decoding, the Euclidean distance of branch metric is multiplied by CSI. To do so, new branch metric values that consider each carrier state information are obtained. We simulated this method in better performance of about 0.15dB to 0.17dB and 2.2dB to 2.9dB in Rayleigh channel than that of the conventional soft decision Viterbi decoding with or without bit interleaver where the constellation is QPSK, 16-QAM and 64-QAM.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.39A no.10
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• pp.593-600
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• 2014

OFDMA systems solves frequency selective fading problem and provides improved performance by optimal allocation of subcarriers and transmit power. Two-way relay systems provide improved spectral efficiency compared to that of the conventional half-duplex relay using bidirectional communications. In legacy OFDMA system such as WiBro, two-way DF relay utilization causes pilot re-assignment and impossibility of channel estimation and decoding at relay nodes by self-interference. In this paper, resource allocation schemes for legacy OFDMA systems with two-way DF relay are proposed. The proposed schemes allocate subcarriers considering destinations nodes which are connected to relay nodes as individual nodes which are directly connected to a base station. Subsequently, the proposed schemes compensate bandwidth loss due to orthogonal allocations by overlapped allocating unused subcarriers at other noes. Numerical simulations show that the proposed resource allocation schemes provide improved performance compared with orthogonal allocation.

• Atmosphere
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• v.27 no.2
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• pp.119-131
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• 2017

We present and discuss the Tropopause Folding Turbulence Detection (TFTD) algorithm for the Korean Communication, Ocean, Meteorological Satellite (COMS) which is originally developed for the Tropopause Folding Turbulence Product (TFTP) from the Geostationary Operational Environmental Satellite (GOES)-R. The TFTD algorithm assumes that the tropopause folding is linked to the Clear Air Turbulence (CAT), and thereby the tropopause folding areas are detected from the rapid spatial gradients of the upper tropospheric specific humidity. The Layer Averaged Specific Humidity (LASH) is used to represent the upper tropospheric specific humidity calculated using COMS $6.7{\mu}m$ water vapor channel and ERA-interim reanalysis temperature at 300, 400, and 500 hPa. The comparison of LASH with the numerical model specific humidity shows a strong negative correlation of 80% or more. We apply the single threshold, which is determined from sensitivity analysis, for cloud-clearing to overcome strong gradient of LASH at the edge of clouds. The tropopause break lines are detected from the location of strong LASH-gradient using the Canny edge detection based on the image processing technique. The tropopause folding area is defined by expanding the break lines by 2-degree positive gradient direction. The validations of COMS TFTD is performed with Pilot Reports (PIREPs) filtered out Convective Induced Turbulence (CIT) from Dec 2013 to Nov 2014 over the South Korea. The score test shows 0.49 PODy (Probability of Detection 'Yes') and 0.64 PODn (Probability of Detection 'No'). Low POD results from various kinds of CAT reported from PIREPs and the characteristics of high sensitivity in edge detection algorithm.