• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.6
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• pp.642-653
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• 2008

This study deals with modeling of head-related transfer functions(HRTFs) using principal components analysis(PCA) in the time and frequency domains. Four PCA models based on head-related impulse responses(HRIRs), complex-valued HRTFs, augmented HRTFs, and log-magnitudes of HRTFs are investigated. The objective of this study is to compare modeling performances of the PCA models in the least-squares sense and to show the theoretical relationship between the PCA models. In terms of the number of principal components needed for modeling, the PCA model based on HRIR or augmented HRTFs showed more efficient modeling performance than the PCA model based on complex-valued HRTFs. The PCA model based on HRIRs in the time domain and that based on augmented HRTFs in the frequency domain are shown to be theoretically equivalent. Modeling performance of the PCA model based on log-magnitudes of HRTFs cannot be compared with that of other PCA models because the PCA model deals with log-scaled magnitude components only, whereas the other PCA models consider both magnitude and phase components in linear scale.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.159-168
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• 2015

Forty-four surface sediments from Doam Bay were analyzed for total organic carbon (TOC), total nitrogen (TN), total metal (Al, Fe, Mn, Cr, Cu, Ni, Pb, Zn) and further chemical partitioning of metals were carried out in some samples. The TOC (0.32~3.10%) and TN (0.03~0.26%) values of the samples were similar to those of other coastal area. The C/N ratios ranged from 7.9 to 11.9 with an average 9.3 which revealed that contribution of terrestrial organic matters was relatively rare. Contents of analysed metals showed a level lower than threshold effects level (TEL) in sediment quality guidelines. Based on the chemical speciation of metals, the lattice fractions were found in the order Cr > Cu > Ni > Zn > Pb > Mn, while Mn and Pb are the ratio of the non-lattice fractions accounted for more than 50%. The average baseline values were obtained relative cumulative frequency curves and linear regression analysis. The respective baseline concentrations for Cu, Ni, Pb, Zn, Cr and Mn were 11.8, 23.1, 26.8, 76.6, 56.7, 585 mg/kg, respectively. Based on geoaccumulation index ($I_{geo}$) with a baseline values of Mn showed that face the contamination phase from estuarine stations. However, in case of Zn and Pb, although there is no sign of contamination, it could be release from sediment when there is a change in the environment, which is caused from the high ratio of non-lattice fractions.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.10
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• pp.188-198
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• 2013

Maximally flat (MAXFLAT) half-band filters usually have wider transition band than other filters. This is due to the fact that the maximum possible number of zeros at $z={\pm}1$ is imposed, which leaves no degree of freedom, and thus no independent parameters for direct control of the frequency response. This paper describes a novel method for the design of FIR halfband filters with an explicit control of the transition-band width. The proposed method is based on a generalized Lagrange halfband polynomial (g-LHBP) with coefficients parametizing a 0-th coefficient $h_0$, and allows the frequency response of this filter type to be controllable by adjusting $h_0$. Then, $h_0$ is modeled as a steepness parameter of the transition band and this is accomplished through theoretically analyzing a polynomial recurrence relation of the g-LHBP. This method also provides explicit formulas for direct computation of design parameters related to choosing a desired filter characteristic (by trade-off between the transition-band sharpness and passband & stopband flatness). The examples are shown to provide a complete and accurate solution for the design of such filters with relatively sharper transition-band steepness than MAXFLAT half-band filters.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1603-1615
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• 2018

In order to achieve the low complexity and area, power in the design of Optical Image Stabilization (OIS) suitable for the smart phone, this paper presents the following design explorations, such as; optimization of gyroscope sampling rate, simple and accurate gyroscope filters, and reduced operating frequency of motion compensation, optimized bit width in ADC and DAC, evaluation of noise effects due to PWM driving. In experiments of gyroscope sampling frequencies, it is found that error values are unvaried in the frequency above 5KHz. The gyroscope filter is efficiently designed by combining the Fuzzy algorithm, to illustrate the reasonable compensation for the angle and phase errors. Further, in the PWM design, the power consumption of 2MHz driving is shown to decrease up to 50% with respect to the linear driving, and the imaging noises are reduced in the driving frequency above 2MHz driving frequency. The operating frequency could be reduced to 5KHz in controller and 10KHz in driver, respectively, in the motion compensation. For ADC and DAC, the optimized exploration experiments verify the minimum bit width of 11bits in ADC as well as 10bits in DAC without the performance degradation.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.194-200
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• 2016

Aflatoxins and ochratoxin A (AFTs and OTA) are secondary fungal metabolites produced by several moulds, mainly by Aspergillus flavus by Aspergillus ochraceus and Penicillium verrucosum, and these toxins can be transferred to animals and humans through the ingestion of contaminated feed and food. This study was to develop the analytical method for determination the levels of AFTs ($B_1$, $B_2$, $G_1$ and $G_2$) and OTA in pork. The AFTs and OTA were analyzed simultaneously by electrospray ionization in positive ion mode and mass reaction monitoring (MRM) after solid phase extract (SPE) columns clean-up. Performance characteristics, such as accuracy, precision, linear range, limit of detection (LOD) and quantification (LOQ), were also determined. Matrix-matched standard calibration was used for quantification, obtaining the recoveries in the range of 67.3~108.2% with the relative standard deviations of < 20%. Limits of detection and quantification were also estimated, obtaining the limits of quantification ranged in $0.7{\sim}1.3{\mu}g/kg$. The results of the inter-day study, which was performed with pork samples for 3 days, showed an accuracy of 92.0~109.9%. The precisions (expressed as relative standard deviation values) for the inter day variation were 2.6~17.8%. The method developed in this study was able to carry out the analysis with the satisfactory intensity and accuracy.

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.123-133
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• 2018

This study aims to evaluate the overall health of the disabled and oral health behavior to determine its relevance to DMFT index. Based on the National Health Nutrition Survey. The survey was conducted on disabled adults over 19years old age in 2013 the first of 6th phase. The data analysis included a general characteristics, disability factors, social economy factors, health factors, oral health behavior factors were cross-analyzed on a composite sample. The general linear model of the combined sample was analyzed to determine the factors affecting the DMFT index of the disabled. The analysis shows that the DMFT index is higher for men than for women, the higher age, the lower level of education, the worse condition of whole body(EQ-5D), the difficulty of Stomatognathic system, the uncomfortable of chewing and the worse oral health conditions subjectively. Therefore, the study objectively identified the overall oral health condition of the adult disabled in Korea, Through this study, a measure should be made to development of comprehensive oral health education program to promote oral health of disabled people and policy measures should be prepared for prevention and care of oral health of disabled people.

• Clinical and Experimental Pediatrics
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• v.59 no.5
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• pp.231-238
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• 2016

Purpose: Lipopolysaccharide-binding protein (LBP) is a 65-kDa acute phase protein, derived from the liver, which is present in high concentrations in plasma. Data regarding the association between circulating plasma LBP levels and obesity-related biomarkers in the pediatric population are scarce. We aimed to determine whether there was a difference in plasma LBP levels between overweight/obese and normal-weight adolescents and to assess the correlation of circulating LBP levels with anthropometric measures and obesity-related biomarkers, including insulin resistance, liver enzyme levels, and lipid profiles. Methods: The study included 87 adolescents aged 12-13 years; 44 were overweight/obese and 43 were of normal-weight. We assessed anthropometric and laboratory measures, including body mass index (BMI), blood pressure, insulin resistance, liver enzyme levels, and lipid profiles. Plasma LBP levels were measured using an enzyme-linked immunosorbent assay. Results: The mean age of the participants was $12.9{\pm}0.3$ years. Circulating plasma LBP levels were significantly increased in overweight/obese participants compared with those in normal-weight participants ($7.8{\pm}1.9{\mu}g/mL$ vs. $6.0{\pm}1.6{\mu}g/mL$, P<0.001). LBP levels were significantly and positively associated with BMI, systolic blood pressure, aspartate aminotransferase, alanine aminotransferase, total cholesterol, low density lipoprotein-cholesterol, fasting glucose and insulin, and insulin resistance as indicated by the homeostatic model assessment of insulin resistance (HOMA-IR) (all P<0.05). In multivariate linear regression analysis, BMI and HOMA-IR were independently and positively associated with plasma LBP levels. Conclusion: LBP is an inflammatory biomarker associated with BMI and obesity-related insulin resistance in adolescents. The positive correlation between these parameters suggests a potentially relevant pathophysiological mechanism linking LBP to obesity-related insulin resistance in adolescents.

• Journal of Advanced Navigation Technology
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• v.14 no.5
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• pp.684-690
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• 2010

Recently, the NG(Next Generation) system is studied for supporting convergence of various services and multi mode of single terminal. And a demand of user for taking the various services is getting increased, for supporting these services, many systems being able to transmit a large message have been appeared. In the NG system, it has to be supporting the CDMA and WCDMA besides the tele communication systems using OFDM method with single terminal An intergrated system can be improved with adopting of SoC technique. For adopting SoC technique on the intergrated terminal, we have to solve the non linear problem of HPA(High Power Amplifier). Nonlinear characteristic of HPA distorts both amplitude and phase of transmit signal, this distortion cause deep adjacent channel interference. We adopt a polynomial pre-distortion technique for this problem. In this paper, a noble modem design for NG mobile communication service and a method using polynomial pre-distorter with PAPR technique for counterbalancing nonlinear characteristic of the HPA are proposed.

• The Korea Journal of Herbology
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• v.26 no.1
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• pp.41-46
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• 2011

Objectives : To quantitate the main compounds and investigate the biological activity of Sosiho-tang (Xiao-Chai-Hu-Tang, SST), simultaneous determination of baicalin and glycyrrhizin, and anti-inflammatory activity were estimated. Methods : A quantitative analysis was performed using a high performance liquid chromatography (HPLC). Reference compounds were separated on a reversed-phase column using gradient elution with water and acetonitrile each containing acetic acid at a flow rate of 1 mL/min. And the productions of nitric oxide (NO) and prostaglandin $(PE)E_2$ were examined by lipopolysaccharide (LPS)-treated RAW 264.7 cells in the presence of the SST. The anti-inflammatory activity of SST was investigated by carrageenin-induced paw edema in rats. The paw volume was measured at 2 and 4 hr following carrageenin-induced paw edema in rats. Results : The correlation coefficients of the compounds showed good linearity ($r^2$ > 0.9992) over the linear range. The precisions of intra- and inter-day were less than 7.0% of relative standard deviation (RSD) values for baicalin and less than 3.5% of RDS valuse for glycyrrhizin. Recovery rates were within the range of 95.41-101.5%. The contents of baicalin and glycyrrhizin in SST were average 70.52, 6.18 mg/g, respectively. And SST exhibited inhibitory effect on NO production in LPS-treated RAW 264.7 cells but not on $PGE_2$ production. Oral administration of SST (1 g/kg) showed a reduction in carrageenin-induced paw edema on rats. Conclusions : The analytical method was applied successfully to measure the contents of baicalin and glycyrrhizin in SST which exhibited anti-inflammatory activities.

• Investigative Magnetic Resonance Imaging
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• v.14 no.1
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• pp.41-46
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• 2010

Purpose : To evaluate the role of magnetic resonance imaging (MRI) in the diagnosis of papillary lesions of the breast. Materials and methods : Among 45 papillary lesions diagnosed at ultrasonography-guided core biopsy (USCB), 27 benign papillary lesions in 22 patients who underwent breast MRI were reviewed. The excsional biopsy was performed in 1-10 days after MRI was done. In MRI findings, lesions were considered suspicious if they show irregular, rim enhancement, or linear enhancement in morphologic evaluation, or washout enhancement pattern of delayed phase in dynamic enhancement characteristics. Diffusionweighted images were analyzed according to visibility of lesions. MRI findings were correlated with pathologic results at excisional biopsy. Results : At excisional biopsy, two lesions (9%) were diagnosed malignant in 22 benign papillary lesions without atypia by USCB and 4 (80%) were malignant in 5 benign papillary lesions with atypia by USCB. Among 18 lesions detected on MRI, 16 lesions showed suspicious findings on MRI, 11 lesions (69%) were diagnosed as benign and 5 (31%) were malignant. Among 12 lesions detected on diffusion weighted imaging, 10 lesions were diagnosed as benign and 2 were malignant. MRI findings were not significantly correlated with pathologic results at excisional biopsy. Conclusion : MRI findings were not useful to predict malignancy in benign papillary lesions diagnosed at USCB, because MRI findings of these were mostly suspicious (88.9%, 16/18). The benign papillary lesion should be included in the false positive lesion on breast MRI.