• Journal of KSNVE
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• v.7 no.6
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• pp.993-1000
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• 1997

This paper presents a new technique of mathematical treatment using a finite element model for analyzing the vibration of the towed line array. Since the towed line array has the axisymmetricity, axisymmetric elements are used in finite element modeling for the towed array structure. The fluid-structure interaction is also considered. The array consists of a series of identical substructures which can include internal structures such as spacers, hydrophones and ropes. That periodicity of substrucutres permits the substructure synthesis technique using characteristic wave guide for analyzing the response of towed array system. This synthesis technique can reduce the cost of computing the array response. It is suggested that a response of towed array can be computed by the finite element method and substructure synthesis technique using wave guide. Several experiments for towed array were performed to verify the present computation technique. The predicted vibration for the towed array shows good agreement with the measured result.

• Genomics & Informatics
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• v.8 no.3
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• pp.138-141
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• 2010

Together with single nucleotide polymorphism (SNP), copy number variations (CNV) are recognized to be the major component of human genetic diversity and used as a genetic marker in many disease association studies. Affymetrix Genome-wide SNP 5.0 is one of the commonly used SNP array platforms for SNP-GWAS as well as CNV analysis. However, there has been no report that validated the accuracy and reproducibility of CNVs identified by Affymetrix SNP array 5.0. In this study, we compared the characteristics of CNVs from the same set of genomic DNAs detected by three different array platforms; Affymetrix SNP array 5.0, Agilent 2X244K CNV array and NimbleGen 2.1M CNV array. In our analysis, Affymetrix SNP array 5.0 seems to detect CNVs in a reliable manner, which can be applied for association studies. However, for the purpose of defining CNVs in detail, Affymetrix Genome-wide SNP 5.0 might be relatively less ideal than NimbleGen 2.1M CNV array and Agilent 2X244K CNV array, which outperform Affymetrix array for defining the small-sized single copy variants. This result will help researchers to select a suitable array platform for CNV analysis.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.9
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• pp.465-471
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• 2006

In this paper, a synchronous permanent magnet planar motor (SPMPM) with Halbach array is proposed. First, we give the equations of the magnetic scalar potential and a series of boundary conditions. The magnetization and flux density distribution of Halbach array are obtained by analytical method; then, the characteristics of this SPMPM such as inductance, back-EMF, and thrust are evaluated. At last, the experiment results are used to verify the analysis property of this SPMPM. By comparison, it can be concluded that the analysis of SPMPM with Halbach magnet array is credible and feasible.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.4
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• pp.439-449
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• 1998

In this paper, error performance of DS-CDMA communication system has been analyzed in a radio channel which is characterized by multi-user interference (MUI). Also, performance improvement has been obtained by both numerical analysis and simulation techniques when 3-element array antenna and co-channel interference (CCI) canceller are employed as a means for overcoming an MUI effect. The MUI was modelled as a gaussian random process. In array antenna scheme we only considered a directivity of antennal. The results show that there is a substantial enhancement in performance by employing an array antenna or a CCI canceller. CCI canceller gives better improvement in performance than the array antenna with D=2.67. Additional improvement can be obtained when the array antenna and the CCI canceller are adopted in cascade form. In this case the error performance approaches that of AWGN environment.

• Steel and Composite Structures
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• v.17 no.5
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• pp.561-572
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• 2014

In this paper, we present the scattering characteristics of infinite and finite array using method of moment (MoM) with Floquet harmonics and asymptotic waveform evaluation (AWE) technique. First, infinite cylindrical dipole array is analyzed using the MoM with entire domain basis function and cylindrical Floquet harmonics. To provide the validity of results, we fabricated the cylindrical dipole array and measured the transmission characteristics. The results show good agreements. Second, we analyzed the scattering characteristics of finite array. A large simulation time is needed to obtain the scattering characteristics of finite array over wide frequency range because Floquet harmonics can't be applied. So, we used the MoM with AWE technique using Taylor series and Pade approximation to overcome the shortcomings of conventional MoM. We calculated the radar cross section (RCS) as scattering characteristics using the proposed method in this paper and the conventional MoM for finite planar slot array, finite spherical slot array, and finite cylindrical dipole array, respectively. The compared results agree well and show that the proposed method in this paper is good for electromagnetic analysis of finite FSS.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.3
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• pp.181-189
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• 2022

The public open signals from Global Navigation Satellite System (GNSS) including Global positioning system (GPS) are used widely by many peoples in the world except for the public regulated restriction signals which are encrypted. Nowadays there are growing concerns about GNSS signal spoofing which can deceive the GNSS receivers by abusing these open services. To counter these spoofing threats, many researches have been studied including array antenna techniques which can detect the direction of arrival by means of Multiple Signal Classification (MUSIC) algorithm. Originally the array antenna techniques were developed to countermeasure the jamming signal in electronic warfare by using the nulling or beamforming algorithm toward a certain direction. In this paper, we study the anti-spoofing techniques using array antenna to overcome the jamming and spoofing issues simultaneously. First, we will present the theoretical analysis results of spoofing signal response of Minimum Variance Distortionless Response (MVDR) algorithm in array antenna. Then the eigenvector algorithm of covariance matrix is suggested and verified to work with the existing anti-jamming method. The modeling and simulation are used to verify the effectiveness of the anti-spoofing algorithm. Also, the field test results show that the array antenna system with the proposed algorithms can perform the anti-spoofing function. This anti-spoofing method using array antenna is very effective in the view point of solving both the jamming and spoofing problems using the same array antenna hardware.

• International Journal of Control, Automation, and Systems
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• v.6 no.6
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• pp.884-893
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• 2008

This paper analyzes, through simulations, GNSS interference mitigation performance against wideband and narrowband interferences by using spatial-temporal adaptive processing(STAP). The mathematical analysis results demonstrate that the array configuration has a considerable effect on the spatial-temporal correlation function. Based on the results, different array configurations are presented to evaluate and observe the effect on interference mitigation. The analysis results are further assessed through simulations.

• Genomics & Informatics
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• v.5 no.3
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• pp.137-139
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• 2007

RAN-aCGH is an R GUI tool for the analysis and visualization of array comparative genomic hybridization (array-CGH) experiments. The tool consists of data-loading, preprocessing for missing data, several methods for statistical identification of DNA copy number aberration, and visualization of the copy number change. RAN-aCGH requires a single input format, provides various visualizations, and allows the addition of a new statistical method, all in a user-friendly graphic user interface (GUI).

• Journal of Information Processing Systems
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• v.3 no.1
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• pp.38-42
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• 2007

Microarray data includes tens of thousands of gene expressions simultaneously, so it can be effectively used in identifying the phenotypes of diseases. However, the retrieval of functional information from a large corpus of gene expression data is still a time-consuming task. In this paper, we propose an efficient method for identifying functional categories of differentially expressed genes from a micro-array experiment by using Gene Ontology (GO). Our method is as follows: (1) The expression data set is first filtered to include only genes with mean expression values that differ by at least 3-fold between the two groups. (2) The genes are then ranked based on the t-statistics. The 100 most highly ranked genes are selected as informative genes. (3) The t-value of each informative gene is imposed as a score on the associated GO terms. High-scoring GO terms are then listed with their associated genes and represent the functional category information of the micro-array experiment. A system called HMDA (Hallym Micro-array Data analysis) is implemented on publicly available micro-array data sets and validated. Our results were also compared with the original analysis.

• Phonetics and Speech Sciences
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• v.4 no.4
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• pp.87-92
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• 2012

Speech enhancement aims to improve speech quality by removing background noise from noisy speech. Independent vector analysis is a type of frequency-domain independent component analysis method that is known to be free from the frequency bin permutation problem in the process of blind source separation from multi-channel inputs. This paper proposed a new method of microphone array based speech enhancement that combines independent vector analysis and beamforming techniques. Independent vector analysis is used to separate speech and noise components from multi-channel noisy speech, and delay-sum beamforming is used to determine the enhanced speech among the separated signals. To verify the effectiveness of the proposed method, experiments for computer simulated multi-channel noisy speech with various signal-to-noise ratios were carried out, and both PESQ and output signal-to-noise ratio were obtained as objective speech quality measures. Experimental results have shown that the proposed method is superior to the conventional microphone array based noise removal approach like GSC beamforming in the speech enhancement.