• 한국수소및신에너지학회논문집
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• 제34권2호
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• pp.205-211
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• 2023

Hydrogen gas is light and diffuses very quickly. Therefore, when a leakage accident occurs, the damage is great, so a technology that can quickly measure the leakage in the air at a long distance is needed. In order to develop hydrogen gas leaked in the atmosphere in a non-contact manner, an experiment was performed to measure hydrogen gas using a lidar technology using the Raman effect. Hydrogen Raman signals were detected using a UV LED light source, which is a Raman light source, and a spectrometer in the ultraviolet region including an optical filter in the 400-430 nm band. To develop this, a Raman lidar optical structure was designed to measure the hydrogen Raman signal at a certain distance, and the hydrogen Raman spectrum was confirmed using a standard gas to evaluate the performance of this optical structure. The linearity was found to be 0.99 using hydrogen standard gas (10, 50, 100, 500, 1,000 ppm). Accordingly, a Raman lidar capable of measuring hydrogen gas rapidly diffusing in the air in an open state was developed to improve the limitations of existing hydrogen sensors.

• ETRI Journal
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• 제24권1호
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• pp.23-30
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• 2002

MPEG-7 Visual Standard specifies a set of descriptors that can be used to measure similarity in images or video. Among them, the Edge Histogram Descriptor describes edge distribution with a histogram based on local edge distribution in an image. Since the Edge Histogram Descriptor recommended for the MPEG-7 standard represents only local edge distribution in the image, the matching performance for image retrieval may not be satisfactory. This paper proposes the use of global and semi-local edge histograms generated directly from the local histogram bins to increase the matching performance. Then, the global, semi-global, and local histograms of images are combined to measure the image similarity and are compared with the MPEG-7 descriptor of the local-only histogram. Since we exploit the absolute location of the edge in the image as well as its global composition, the proposed matching method can retrieve semantically similar images. Experiments on MPEG-7 test images show that the proposed method yields better retrieval performance by an amount of 0.04 in ANMRR, which shows a significant difference in visual inspection.

• 환경위생공학
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• 제10권1호
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• pp.66-75
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• 1995

This survey is executed about the water quality and improvement measure of Imjin- river. The results are summarized as follows; 1 ) Ammonia nitrogen concentration in tap water was two times higher than drinking water standard. 2) The concentration of BOD in textile wastewater was 235ppm which is higher than wastewater distribution standard and leather wastewater showed high nitrogen concentration. 3) Water quality of the Imjin- river upstream was not in problem but that of Shin- stream showed somewhat high concentration in BOD, COD, and ammonia nitrogen. Especially the detected Cynide compound on the lower of Shin- stream implied seriously polluted condition. 4) The heavy metal in soil of the river bed was not detected but iron, zinc was detected to high concentration. 5) It Is urgently suggested to build more municipal sewage and sanitary treatment plants, and run dredging and river bed rearrangement project. 6) The Construction of the wastewater treatment complexes of relevant industries shall be propelled as soon as possible.

• 대한음성학회지:말소리
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• 제46호
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• pp.103-115
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• 2003

In this paper, we proposed Background Model Set algorithm used in the speaker verification to improve calculating confidence measure(CM) in speech recognition. CM is to display relative likelihood between recognized models and antiphone models. In previous method calculating of CM, we calculated probability and standard deviation using all phonemes in composition of antiphone models. At this process, antiphone CM brought bad recognition result. Also, recognition time increases. In order to solve this problem, we studied about method to reconstitute average and standard deviation using BMS algorithm in CM calculation.

• International Journal of Safety
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• 제1권1호
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• pp.28-35
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• 2002

Kullback Discrimination Information (KDI) is one of the pattern recognition methods. KDI defined as a measure of the mutual dissimilarity computed between two time series was studied for detection and classification of bearing flaking on outer-race and inner-races. To model the damages, the bearings in normal condition, outer-race flaking condition and inner-races flaking condition were provided. The vibration sensor was attached by the bearing housing. This produced the total 25 pieces of data each condition, and we chose the standard data and measure of distance between standard and tested data. It is difficult to detect the flaking because similar pulses come out when balls pass the defection point. The detection and classification method for inner and outer races are defected by KDI and nearest neighbor classification rule is proposed and its high performance is also shown.

• 한국재난정보학회 논문집
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• 제2권1호
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• pp.81-89
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• 2006

As the quality of the rising the desire for safety life and the need of safety education to prevent disasters or big safety accident have been shown. Therefore the superintendent of education for safety experience carry out a policy for set up. However, it is unclear the appropriateness of safety education program and safety standard of facilities of introductions in the safety experience center. therefore, in the result of this study will be the basic information for the realities of experience in the place of safety experience education and propose the reform measure.

• 정보저장시스템학회논문집
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• 제5권2호
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• pp.89-95
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• 2009

We setup the system to measure the noise characteristics of the 5M complementary metal-oxide semiconductor (CMOS) image sensor by generic measurement indicator of Standard mobile imaging architecture (SMIA) which is one of internal standard of mobile imaging architecture. To evaluate the effect of environment and setting parameters, such as temperature and integration time, we measure the variation of the dark signal, dynamic range and fixed pattern noise of image sensor. We also detect the number of defective pixels and cluster defects defined as adjacent single defect pixels at 5M CMOS image sensor. Then, we find the existence of some cluster defects in experiment, which are not expected in calculation.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2005년도 춘계학술발표회
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• pp.411-412
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• 2005

There are some differences as a result of comparison between internal and external standard method. Thin-film XRD was used to measure the thin damaged layer by proton irradiation. Experiment was performed by external standard method to measure bulk sample accurately. A little changes of crystallite size and lattice parameter by small dose were observed. X-ray penetrates too deeply above damaged layer of graphite despite of small X-ray incident angle.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2003년도 5월 학술대회지
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• pp.79-82
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• 2003

In this paper, we proposed Backgorund Model Set algorithm for the speaker verification to improve the shortcoming of calculating process in conventional confidence measure(CM). CM is to display relative likelihood between recognized models and unrecognized models. Unrecognized models is known as antiphone models. Calculate probability and standard deviation using all phonemes at process that compose antiphone model. At this process, antiphone CM brought bad result. Also, recognition time increases. In order problem, we studied about method to reconstitute average and standard deviation taking BMS algorithm using antiphoneme that near phoneme of CM calculation.

• 한국음향학회지
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• 제40권3호
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• pp.241-246
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• 2021

현재 라우드스피커 시스템은 다양한 입력 채널 및 앰프를 포함하는 액티브 스피커로 변화하고 있다. 이러한 액티브 스피커의 경우 기존 패시브 스피커 혹은 유닛 단품 측정 표준인 IEC 60268-5 만으로 측정이 불가능한 경우가 많다. 본 논문은 IEC한국 대표로 IEC60268-21 표준을 제정하면서 새롭게 정의한 아날로그, 디지털 입력 및 유선, 무선 입력 채널을 가지고 다양한 제어 기능을 가진 파워 앰프를 내장한 액티브 스피커 측정 표준에 대해 상세하게 알아보고자 한다.