• BMB Reports
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• 제40권2호
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• pp.226-231
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• 2007

Housekeeping genes are widely used as internal controls in a variety of study types, including real time RT-PCR, microarrays, Northern analysis and RNase protection assays. However, even commonly used housekeeping genes may vary in stability depending on the cell type or disease being studied. Thus, it is necessary to identify additional housekeeping-type genes that show sample-independent stability. Here, we used statistical analysis to examine a large human microarray database, seeking genes that were stably expressed in various tissues, disease states and cell lines. We further selected genes that were expressed at different levels, because reference and target genes should be present in similar copy numbers to achieve reliable quantitative results. Real time RT-PCR amplification of three newly identified reference genes, CGI-119, CTBP1 and GOLGAl, alongside three well-known housekeeping genes, B2M, GAPD, and TUBB, confirmed that the newly identified genes were more stably expressed in individual samples with similar ranges. These results collectively suggest that statistical analysis of microarray data can be used to identify new candidate housekeeping genes showing consistent expression across tissues and diseases. Our analysis identified three novel candidate housekeeping genes (CGI-119, GOLGA1, and CTBP1) that could prove useful for normalization across a variety of RNA-based techniques.

• Food Science and Biotechnology
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• 제14권4호
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• pp.554-557
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• 2005

As a device for taste sensation, an 8-channel taste evaluation system was prepared and applied for discriminant analysis of marketed liquor. The biomimetic polymer membranes for the system were prepared through a casting procedure by employing polyvinyl chloride, bis (2-ethylhexyl)sebacate as plasticizer and electroactive materials such as valinomycin in the ratio of 33:66:1, and were separately attached over the sensitive area of ion-selective electrodes to construct the corresponding taste sensor array. The sensor array in conjunction with a double junction reference electrode was connected to a high-input impedance amplifier and the amplified sensor signals were interfaced to a personal computer via an A/D converter. When the signal data from the sensor array for 3 groups of marketed liquor like Maesilju, Soju and beer were analyzed by principal component analysis after normalization, it was observed that the 1st, 2nd and 3rd principal component were responsible for most of the total data variance, and the analyzed liquor samples were discriminated well in 2 dimensional principal component planes composed of the 1st-2nd and the 1st-3rd principal component.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2002년도 춘계 학술발표회 논문집
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• pp.51-58
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• 2002

The relative site amplification factors in southern Korea were determined from coda waves using coda normalization method. The seismograms of 15 events at 79 stations were used in this study. Seismogram envelopes were obtained by the Hilbert transform of bandpass-filtered velocity seismograms with frequency bands at 1-2Hz, 2-4Hz, 4-8Hz, 8-l6Hz and 16-32Hz. The envelopes were stabilized by application of moving-average scheme with time window of 1 second. The relative amplitudes of seismogram envelope were computed by dividing the amplitude of seismogram envelope at one site by the amplitude of seismogram envelope at reference site. The relative site amplification factors were obtained by taking averages of the relative amplitude. Values of relative site amplification factors in southern Korea are generally low in western area and high in eastern area.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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• pp.504-507
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• 2006

Airborn Lidar technology has been applied to diverse applications with the advantages of accurate 3D information. Further, Lidar intensity, backscattered signal power, can provid us additional information regarding target's characteristics. Lidar intensity varies by the target reflectance, moisture condition, range, and viewing geometry. This study purposes to generate normalized airborne LiDAR intensity image considering those influential factors such as reflectance, range and geometric/topographic factors (scan angle, ground height, aspect, slope, local incidence angle: LIA). Laser points from one flight line were extracted to simplify the geometric conditions. Laser intensities of sample plots, selected by using a set of reference data and ground survey, werethen statistically analyzed with independent variables. Target reflectance, range between sensor and target, and surface slope were main factors to influence the laser intensity. Intensity of laser points was initially normalized by removing range effect only. However, microsite topographic factor, such as slope angle, was not normalized due to difficulty of automatic calculation.

• 한국산학기술학회논문지
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• 제17권3호
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• pp.450-456
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• 2016

케이블에 인가되는 신호로 의사잡음 수열을 사용하여 인가신호와 반사신호의 시간 상관 분석을 실시하여 케이블 고장을 검출하는 STDR (sequence time domain reflectometry)은 노이즈 환경에 강하고, 단선, 합선을 포함한 간헐적 고장의 검출이 가능한 것으로 알려져 있다. 하지만 고장 위치의 거리가 멀거나 경미한 고장의 경우 반사신호의 감쇄가 크고 상관계수가 작아지게 되어, 케이블 고장 판별이 어렵거나 측정 거리 오차가 커진다. 또한 위상과 피크치 검출에 의한 고장 탐지 자동화가 어렵게 된다. 따라서 본 논문에서는 기존의 STDR의 고장 검출 성능을 향상시키기 위해 케이블에 인가되는 인가신호의 상관계수의 최댓값을 검출하고, 다음으로 인가신호를 제거하여 반사신호의 상관계수의 최댓값을 검출하는 알고리즘을 제안하였다. 제안된 방법은 저압 전력 케이블에서의 고장 검출 실험을 통해 성능을 입증하였다. 그 결과 제안된 방법은 신호가 감쇄되더라도 전통적인 STDR보다 고장 여부의 정확한 구분과 위치의 추적이 가능하였다. 또한 기준신호 제거와 상관계수의 정규화를 통해 위상과 최대값 검출 방법을 사용함으로써 자동 고장 판별과 거리 계산에 오류가 발생하지 않았다.

• 대한전자공학회논문지SP
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• 제41권3호
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• pp.209-219
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• 2004

본 논문에서는 핵심어 검출 시스템을 실시간 적용이 가능한 하드웨어로 구현하기 위해 연산량이 적고 구조가 간단한 단일 끝점 DTW 방법을 제안한다. 제안된 알고리즘은 일반적 DTW가 양쪽 끝점을 요구하는데 비하여 단지 한쪽 끝점만 필요하므로 이용하기에 편리하며, 국부 검색의 연속이 전역 경로를 이루게 되므로 매우 적은 연산량을 가진다. 그리고, 제안한 단일 끝점 DTW가 보다 나은 성능을 지니도록 하기 위해 새로운 경사 가중치와 거리 측정법을 가지도록 하였다. 이외에도, 단일 끝점 DTW는 특징벡터 정규화를 적용하여 특징벡터 각각의 차원에서 데이터들이 같은 표준편차를 가지게 하며 모든 프레임이 같은 에너지를 가지도록 정규화 되었다 또한, 주어진 학습 패턴들에 클러스터링을 적용한 후, 각 클러스터 내에서 평균을 계산하여 구한 패턴을 해당 핵심어를 대표하는 여러 개의 기준패턴으로 삼았다. 이러한 기준패턴들과 입력 음성의 특징벡터가 이미 정해진 문턱값 보다 작은 거리 내에 있을 때 핵심어는 검출된다. 제안된 알고리즘을 고립단어 음성인식과 핵심어 검출 실험에 적용하여 다른 방법을 이용한 결과보다 성능이 뛰어남을 확인하였다.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제11권5호
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• pp.211-220
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• 2022

최근 4차 산업혁명으로 촉발된 스마트공장에 관한 연구가 활발히 진행되고 있다. 이에 따라 제조업에서는 강건한 성능의 딥러닝 기술을 바탕으로 생산성 향상과 품질 향상을 위해 다양한 연구를 진행 중이다. 본 논문은 타이어 제조공정의 육안검사 단계에서 타이어 표면 결함을 검출하는 방법에 관한 연구로서 3D 카메라를 통해 취득한 깊이 이미지를 이용한 타이어 표면 결함 검출 방법을 소개한다. 본 연구에서 다루는 타이어 표면 깊이 이미지는 타이어 표면의 얕은 깊이로 인해 발생되는 낮은 깊이 대비와 데이터 취득 환경으로 인해 기준 깊이 값의 차이가 발생하는 문제가 있다. 그리고 제조업의 특성상 검출 성능과 함께 실시간으로 처리될 수 있는 성능을 지닌 알고리즘이 요구된다. 따라서, 본 논문에서는 타이어 표면 결함 검출 알고리즘이 복잡한 알고리즘 파이프라인으로 구성되지 않도록 상대적으로 단순한 방법들을 통해 깊이 이미지를 정규화하는 방법을 연구하였으며 검출 성능과 속도를 모두 만족할 수 있는 딥러닝 방법인 YOLO V3를 이용하여 일반적인 정규화 방법과 본 논문에서 제안하는 정규화 방법의 비교 실험을 진행하였다. 실험의 결과로 본 논문에서 제안한 정규화 방법으로 mAP 0.5 기준 약 7% 성능이 향상된 것을 확인하였으며 본 논문에서 제시한 방법이 효과적임을 보였다.

• Ocean and Polar Research
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• 제26권3호
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• pp.439-451
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• 2004

Total solar irradiance (750), total UV irradiunce (TUV) and erythemal UV irradiance (EUV) measured at King Sejong station $(62.22^{\circ}S,\;58.78^{\circ}W)$ in west Antarctica have been used together with total ozone, cloud amount and snow cover to examine the effects of ozone, cloud and snow surface on these surface solar inadiunce over the period of 1998-2003. The data of three solar components for each scan were grouped by cloud amount, n in oktas $(0{\leq}n<3,\;3{\leq}n<4,\;4{\leq}n<5,\;5{\leq}n<6,\;6{\leq}n<7\;and\;7{\leq}n<8)$ and plotted against solar zenith angle (SZA) over the range of $45^{\circ}\;to\;75^{\circ}$. The radiation amplification factor (RAE) is used to quantify ozone effect on EUV. RAF of EUV decreases from 1.51 to 0.94 under clear skies but increases from 0.94 to 1.85 under cloudy skies as SZA increases, and decreases from 1.51 to 1.01 as cloud amount increases. The effects of cloud amount and snow surface on EUV are estimated as a function of SZA and cloud amount after normalization of the data to the reference total ozone of 300 DU. In order to analyse the transmission of solar radiation by cloud, regression analyses have been performed for the maximum values of solar irradiance on clear sky conditions $(0{\leq}n<3)$ and the mean values on cloudy conditions, respectively. The maximum regression values for the clear sky cases were taken to represent minimum aerosol conditions fur the site and thus appropriate for use as a normalization (reference) factor for the other regressions. The overall features for the transmission of the three solar components show a relatively high values around SZAs of $55^{\circ}\;and\;60^{\circ}$ under all sky conditions and cloud amounts $4{\leq}n<5$ and $5{\leq}n<6$. The transmission is, in general, the largest in TUV and the smallest in EUV among the three components of the solar irradiance. If the ground is covered with snow on partly cloudy days $(6{\leq}n<7)$, EUV increases by 20 to 26% compared to snow-free surface around SZA $60^{\circ}-65^{\circ}$, due to multiple reflections and scattering between the surface and the clouds. The relative difference between snow surface and snow-free surface slowly increases from 9% to 20% as total ozone increases from 100 DU to 400 DU under partly cloud conditions $(3{\leq}n<6)$ at SZA $60^{\circ}$. The snow effects on TUV and TSO are relatively high with 32% and 34%, respectively, under clear sky conditions, while the effects changes to 36% and 20% for TUV and TSO, respectively, as cloud amount increases.

• Parasites, Hosts and Diseases
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• 제54권1호
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• pp.39-46
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• 2016

Theileria annulata is a tick-borne intracellular protozoan parasite that causes tropical theileriosis, a fatal bovine lymphoproliferative disease. The parasite predominantly invades bovine B lymphocytes and macrophages and induces host cell transformation by a mechanism that is not fully comprehended. Analysis of signaling pathways by quantitative real-time PCR (qPCR) could be a highly efficient means to understand this transformation mechanism. However, accurate analysis of qPCR data relies on selection of appropriate reference genes for normalization, yet few papers on T. annulata contain evidence of reference gene validation. We therefore used the geNorm and NormFinder programs to evaluate the stability of 5 candidate reference genes; 18S rRNA, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), ACTB (${\beta}-actin$), PRKG1 (protein kinase cGMP-dependent, type I) and TATA box binding protein (TBP). The results showed that 18S rRNA was the reference gene most stably expressed in bovine PBMCs transformed and non-transformed with T. annulata, followed by GAPDH and TBP. While 18S rRNA and GAPDH were the best combination, these 2 genes were chosen as references to study signaling pathways involved in the transformation mechanism of T. annulata.