• Asian-Australasian Journal of Animal Sciences
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• 제18권5호
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• pp.643-648
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• 2005

Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.

• Annals of Clinical Neurophysiology
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• 제7권1호
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• pp.7-12
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• 2005

Background: Essential tremor (ET) is a common movement disorder that often causes functional disability. There have been very few investigations about the clinical characteristics of ET in Korea. Therefore, we performed a study showing the clinical features and electrophysiological findings of ET. Methods: We analyzed medical records and accelerometry data of 152 patients (male vs female; 79 vs 73) with ET, who visited the Neurology Clinic of Hospital from 2000 to 2003. Clinical characteristics of ET were summarized including the age of onset, family history, tremor type, body part involved, and associated symptoms. The frequency of tremor was recorded and the spectral analysis of tremor was performed. Results: The age of tremor onset showed bimodal distribution with peaks in the 2nd and 5th decades. Family history was found in 46 patients (30.3%). The patients with the family history presented earlier onset of tremor than patients without the history (mean age of onset, y: 35.2 vs. 49.9, P < 0.001). Tremor appeared most frequently in hands (94%), and followed by head (25%). In head tremor, "no-no" pattern was mainly observed and the head tremor was more frequently observed in female. The frequency of tremor was negatively correlated with age (r=-0.49, P<0.001). Conclusions: The present study indicated some important findings about ET: (1) bimodal distribution for an age of onset, (2) younger age of onset in patients with a family history, (3) decreasing frequency of the tremor according to age, and (4) higher prevalence of head tremor in female patients.

• Asian-Australasian Journal of Animal Sciences
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• 제17권12호
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• pp.1736-1740
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• 2004

Since the application of relatively high levels of heavy metals in the compost poses a potential hazard to plants and animals, the content of heavy metals in the compost with animal manure is important to know if it is as a fertilizer. Measurement of heavy metals content in the compost by chemical methods usually requires numerous reagents, skilled labor and expensive analytical equipment. The objective of this study, therefore, was to explore the application of near-infrared reflectance spectroscopy (NIRS), a nondestructive, cost-effective and rapid method, for the prediction of heavy metals contents in compost. One hundred and seventy two diverse compost samples were collected from forty-seven compost facilities located along the Han river in Korea, and were analyzed for Cr, As, Cd, Cu, Zn and Pb levels using inductively coupled plasma spectrometry. The samples were scanned using a Foss NIRSystem Model 6500 scanning monochromator from 400 to 2,500 nm at 2 nm intervals. The modified partial least squares (MPLS), the partial least squares (PLS) and the principal component regression (PCR) analysis were applied to develop the most reliable calibration model, between the NIR spectral data and the sample sets for calibration. The best fit calibration model for measurement of heavy metals content in compost, MPLS, was used to validate calibration equations with a similar sample set (n=30). Coefficient of simple correlation (r) and standard error of prediction (SEP) were Cr (0.82, 3.13 ppm), As (0.71, 3.74 ppm), Cd (0.76, 0.26 ppm), Cu (0.88, 26.47 ppm), Zn (0.84, 52.84 ppm) and Pb (0.60, 2.85 ppm), respectively. This study showed that NIRS is a feasible analytical method for prediction of heavy metals contents in compost.

• 성인간호학회지
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• 제24권2호
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• pp.139-148
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• 2012

Purpose: A study was designed to compare heart rate variability (HVR) of older adults with postprandial hypotension (PPH) with older adults with no PPH. Methods: The samples were community-dwelling older adults (${\geq}$ 60 years old) with PPH (n=35) and without PPH (n=35). HRV was measured by 10 minutes of electrocardiography using Physiolab 400 and analyzed in time domain (SDNN) and with power spectral analysis in frequency domain (TP, LF, HF, LF/HF). Blood pressure was measured every 15 minutes before and until 120 minutes after the meal. Results: All HRV parameters were lower in the PPH group compared to those with no PPH. Specifically the measures of SDNN, TP, LF, and LF/HF of the PPH group were significantly lower (U=385.0, $p$=.008; U=361.0, $p$=.003; U=375.0, $p$=.005; U=368.0, $p$=.004, respectively). Further, the LF and LF/HF of SBP (${\geq}140$ mmHg) group and the LF/HF of DBP (${\geq}$ 90 mmHg) group were significantly lower ($x^2$=6.33, $p$=.042; $x^2$=33.10, $p$ <.001; $x^2$=11.03, $p$=.004, respectively). Conclusion: These findings indicate that the autonomic nervous functions in persons with PPH are less activated than those persons with no PPH. The findings contribute to an understanding of HRV and the association of autonomic nervous function with the mechanism of PPH.

• 한국음향학회지
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• 제35권1호
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• pp.49-54
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• 2016

본 논문에서는 커널 백피팅 알고리즘에 가중 ${\beta}$-지수승 최소평균제곱오차 추정방식(weighted ${\beta}$-order minimum mean square error: WbE)을 적용한 보컬음 분리 방식에 대해 제안한다. 음성 향상 방식에서, WbE는 진폭 성분 기반 MMSE(Minimum Mean Square Error) 추정방식, 로그 스펙트럼 진폭 기반 MMSE 추정방식 등과 같은 기존의 베이지안(Bayesian) 기반의 추정방식들 보다 객관적 및 주관적 측면에서 모두 보다 높은 성능을 나타내는 방식으로 잘 알려져 있다. 이에 본 논문에서는 기본적인 반복적 커널 백피팅 알고리즘에 WbE를 적용하여 음악 신호에서의 보컬음 분리 성능을 향상시키고자 하였다. 실험결과는 본 논문에서 제안한 방식이 기존의 분리 방식보다 분리 성능이 더 뛰어나다는 것을 보인다.

• 생물정신의학
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• 제20권4호
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• pp.119-128
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• 2013

Objectives Memory impairment is a very important mental health issue for elderly and adults. Mild cognitive impairment (MCI) is a prodromal stage of Alzheimer's disease (AD). Early detection of the prodromal stage of patients with AD is an important topic of interest for both mental health clinicians and policy makers. Methods Electroencephalograpgy (EEG) has been used as a possible biological marker for patients with MCI, and AD. In this review, we will summarize the clinical implications of EEG and ERP as a biological marker for AD and MCI. Results EEG power density, functional coupling, spectral coherence, synchronization, and connectivity were analyzed and proved their clinical efficacy in patients with the prodromal stage of AD. Serial studies on late event-related potentials (ERPs) were also conducted in MCI patients as well as healthy elders. Even though these EEG and ERP studies have some limitations for their design and method, their clinical implications are increasing rapidly. Conclusion EEG and ERP can be used as biological markers of AD and MCI. Also they can be used as useful tools for early detection of AD and MCI patients. They are useful and sensitive research tools for AD and MCI patients. However, some problems remain to be solved until they can be practical measures in clinical setting.

• 한국한의학연구원논문집
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• 제13권3호
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• pp.157-163
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• 2007

Objective: Polygonum multiflorum Thunberg (Polygonaceae) has been traditionally used as a tonic and the purgative in China and Korea. The genus Polygonum is a source of a wide range of phenolic compound, flavanoids, anthraquinones, stilbenes and tannins. In this study, three anthraquinones were isolated and quantitative determination of anthraquinones from P multiflorum has been developed for quality standardization. Methods : Three anthraquinone derivatives were isolated from a methanol extract of the radix of P. multiflorum by the chromatographic separation. Their structures were identified as emodin, physcion and ${\omega}$-hydroxyemodin on the basis of spectral data (MS, lH-NMR, 13C-NMR) and chemical analysis. HPLC analysis was performed to determine the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin in P. multiflorum from different specimens were collected from twenty Korean markets. Results: According to the results, the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin were 0.145%, 0.434%, 0.016%, 0.026%, 0.030% by HPLC, respectively. Conclusions : In these results, we have determined the contents of emodin, physcion, chrysophanol, rhein and ${\omega}$-hydroxyemodin in P. multiflorum, respectively. We hope that this study will contribute to the standardization and quality control of herbal medicine.

• 분석과학
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• 제15권5호
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• pp.399-409
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• 2002

글로우방전 (Glow Discharge)을 이용한 원자방출 분광계의 On-line 분광분석을 위해 개발된 본 시스템을 위한 프로그램은 주변 광학기기들을 제어하는 부분과 스펙트럼의 비선형적인 오차를 줄여 보다 정확한 결과를 얻기 위해 인공지능 기법을 도입한 스펙트럼 해석 부분으로 구성되어져 있다. McPHERSON 207 Monochromator를 GPIB 통신 프로토콜로서 제어하였으며, (주)Photon_Tek에서 제작한 A/D Amplifier를 사용하여 PMT로부터 검출 신호를 측정할 수 있었다. 인공지능 기법인 HNN(Hybrid Neural Network)을 스펙트럼 해석 부분에 도입하여 P, Cu, Fe, Cr, 등의 정성 분석과, Cd 10 ppb의 미량 검출을 통한 정량분석을 기존의 상용화된 방법보다 정확하게 수행할 수 있었다.

• Rapid Communication in Photoscience
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• 제3권1호
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• pp.16-19
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• 2014

Anodic self-organized titania nanotube (TNT) arrays have a great potential as efficient electron-transport materials for dye-sensitized solar cells (DSSC). Herewith we report the photovoltaic and kinetic investigations for a series of heteroleptic ruthenium complexes (RD16-RD18) sensitized on TNT films for DSSC applications. We found that the RD16 device had an enhanced short-circuit current density ($J_{SC}/mAcm^{-2}=15.0$) and an efficiency of power conversion (${\eta}=7.2%$) greater than that of a N719 device (${\eta}=7.1%$) due to the increasing light-harvesting and the broadened spectral features with thiophene-based ligands. However, the device made of RD17 (adding one more hexyl chain) showed smaller $J_{SC}(14.1mAcm^{-2})$ and poorer ${\eta}(6.8%)$ compare to those of RD16 due to smaller amount of dye-loading and less efficient electron injection for the RD17 device than for the RD16 device. For the RD18 dye (adding one more thiophene unit and one more hexyl chain), we found that the device showed even lower $J_{SC}(13.2mAcm^{-2}) $ that led to a poorest device performance (${\eta}=6.2%$) for the RD18 device. These results are against to those obtained from the same dyes sensitized on $TiO_2$ nanoparticle films and they can be rationalized according to the electron transport kinetics measured using the methods of charge extraction and transient photovoltage decays.

• Korean Journal of Acupuncture
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• 제20권2호
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• pp.31-46
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• 2003

Objectives : The aim of this study was to examine the effects of electroacupuncture(EA) at the BL60 (Kollyun) on normal humans using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 channel EEG study was carried out in 10 subjects $(10\;males;\;age=22.4{\pm}0.5$ years). Results : In alpha band, the power values at Fz during the non-acupoint treatment and at Fp2, T5 during the BL60-acupoint treatment significantly were decreased. In beta band, the power values at C3, Po2, O2, Oz during the BL60-acupoint treatment significantly were increased than the before-acupuncture treatment. In theta band, the power values at F7 during the BL60-acupoint treatment significantly was increased. However, the comparison with that before and after the treatment shows no significant differences in all channels.