• 제목/요약/키워드: low background

검색결과 3,408건 처리시간 0.03초

Study of Naturally Occurring Radioactive Material Present in Deep Soil of the Malwa Region of Punjab State of India Using Low Level Background Gamma-Ray Spectrometry

  • Srivastava, Alok;Chahar, Vikash;Chauhan, Neeraj;Krupp, Dominik;Scherer, Ulrich W.
    • Journal of Radiation Protection and Research
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    • 제47권1호
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    • pp.16-21
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    • 2022
  • Background: Epidemiological observations such as mental retardation, physical deformities, etc., in children besides different types of cancer in the adult population of the Malwa region have been reported. The present study is designed to get insight into the role of naturally occurring radioactive material (NORM) in causing detrimental health effects observed in the general population of this region. Materials and Methods: Deep soil samples were collected from different locations in the Malwa region. Their activity concentrations were determined using low-level background gammaray spectrometry. High efficiency and high purity germanium detector capped in a lead-shielded chamber having a resolution of 1.8 keV at 1,173 keV and 2.0 keV at the 1,332 keV line of 60Co was used in the present work. Data were evaluated with Genie-2000 software. Results and Discussion: Mean activity concentrations of 238U, 232Th, and 40K in deep soil were found to be 101.3 Bq/kg, 65.8 Bq/kg, and 688.6 Bq/kg, respectively. The mean activity concentration of 238U was found to be three and half times higher than the global average prescribed by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR). It was further observed that the activity concentration of 232Th and 40K has a magnitude that is nearly one and half times higher than the global average prescribed by UNSCEAR. In addition, the radioisotope 137Cs which is likely to have its origin in radiation fallout was also observed. It is postulated that the NORM present in high quantity in deep soil somehow get mobilized into the water aquifers used by the general population and thereby causing harmful health problems. Conclusion: It can be stated that the present work has been able to demonstrate the use of low background gamma-ray spectrometry to understand the role of NORM in causing health-related effects in a general population of the Malwa region of Punjab, India.

이중 배경 모델을 이용한 급격한 조명 변화에서의 전경 객체 검출 (Detecting Foreground Objects Under Sudden Illumination Change Using Double Background Models)

  • 사이드 마흐모드포어;김만배
    • 방송공학회논문지
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    • 제21권2호
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    • pp.268-271
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    • 2016
  • 배경 모델과 배경 차분화로 구성되어 있는 전경객체 추출은 다양한 컴퓨터 비젼 응용에서 중요한 기능이다. 조명 변화를 고려하지 않은 기존 방법들은 급격한 조명 변화에서는 성능이 저하된다. 본 레터에서는 이 문제를 해결할 수 있는 조명 변화에 강인한 배경 모델링 방법을 제안한다. 제안 방법은 다른 적응률을 가진 두 개의 배경 모델을 사용함으로써 조명 조건에 신속하게 적응할 수 있다. 본 논문의 제안 방법은 non-parametric 기법으로서 실험에서는 기존 non-parametric 기법들보다 우수한 성능 및 낮은 복잡도를 보여줌을 증명하였다.

고정형 임베디드 감시 카메라 시스템을 위한 다중 배경모델기반 객체검출 (Multiple-Background Model-Based Object Detection for Fixed-Embedded Surveillance System)

  • 박수인;김민영
    • 제어로봇시스템학회논문지
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    • 제21권11호
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    • pp.989-995
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    • 2015
  • Due to the recent increase of the importance and demand of security services, the importance of a surveillance monitor system that makes an automatic security system possible is increasing. As the market for surveillance monitor systems is growing, price competitiveness is becoming important. As a result of this trend, surveillance monitor systems based on an embedded system are widely used. In this paper, an object detection algorithm based on an embedded system for a surveillance monitor system is introduced. To apply the object detection algorithm to the embedded system, the most important issue is the efficient use of resources, such as memory and processors. Therefore, designing an appropriate algorithm considering the limit of resources is required. The proposed algorithm uses two background models; therefore, the embedded system is designed to have two independent processors. One processor checks the sub-background models for if there are any changes with high update frequency, and another processor makes the main background model, which is used for object detection. In this way, a background model will be made with images that have no objects to detect and improve the object detection performance. The object detection algorithm utilizes one-dimensional histogram distribution, which makes the detection faster. The proposed object detection algorithm works fast and accurately even in a low-priced embedded system.

The Functional Relevance of Prepro-melanin Concentrating Hormone (pMCH) to Skin Color Change, Blind-side Malpigmentation and Feeding of Oliver Flounder Paralichthys olivaceus

  • Kang, Duk-Young;Kim, Hyo-Chan;Kang, Han-Seung
    • Fisheries and Aquatic Sciences
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    • 제17권3호
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    • pp.325-337
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    • 2014
  • To assess the functional structure of prepro-melanin-concentrating hormone (pMCH), we isolated and cloned pMCH (of-pMCH) mRNA from the brain of the olive flounder, Paralichthys olivaceus, and compared its amino acid sequence with those from other animals. In addition, to examine whether activation of the brain of-pMCH gene is influenced by background color, density, and feeding, we compared pMCH mRNA activities against different background colors (bright and dark) and at different densities (100% PCA and 200% PCA). To examine whether the pMCH gene is related with malpigmentation of blind-side skin and appetite, we compared pMCH gene expression between ordinary and hypermelanic flounders, and between feeding and fasting flounders. The of-pMCH cDNA was 405 bp in the open reading frame [ORF] and encoded a protein of 135 amino acids; MCH was 51 bp in length and encoded a protein of 17 amino acids. An obvious single band of the expected size was obtained from the brain and pituitary by RT-PCR. In addition, of-pMCH gene activity was significantly higher in the bright background only at low density (< 100% PCA) making the ocular skin of fish whitening, and in ordinary fish. However, the gene activity was significantly decreased in dark background, at high density (>200% PCA), and in hypermelano fish. These results suggest that skin whitening camouflage of the flounder is induced by high MCH gene activity, and the density disturbs the function of background color in the physiological color change. Moreover, our data suggest that a low level of MCH gene activity may be related to malpigmentation of the blind-side skin. In feeding, although pMCH gene activity was significantly increased by feeding in the white background, the pMCH gene activity in the dark background was not influenced by feeding, indicating that the MCH gene activity increased by feeding can be offset by dark background color, or is unaffected by appetite. In conclusion, this study showed that MCH gene expression is related to ocular-skin whitening camouflage and blind-skin hypermelanosis, and is influenced by background color and density.

무채색 무늬가 포함된 배경색의 파스텔색상에 따른 뇌파반응 (Brain Waves Evoked by the Changes of Background Pastel Colors with a Pattern of Achromatic Color)

  • 이희란;김소영;김기성;홍경희
    • 한국의류산업학회지
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    • 제19권5호
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    • pp.653-660
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    • 2017
  • Recently, consumers' evaluation and purchase of online design has been increasing due to the popularization of designing through personal computers, but there has not been enough studies on consumers' brain wave responses depending on the change of PC monitor's color. Therefore, this study investigated how brain waves changed when different background colors with gray patterns were presented through PC monitors. Six background colors with same tone of slightly low saturation were selected, including ivory, yellow, pink, green, blue and pure white as a base color. The brightness and characteristics of color used were analyzed using the luminance meter and color scales. Brain wave was measured by EEG measurement equipment. Brain wave measurement was carried out with 9 subjects at 6 points: F3, F4, T3, T4, O1, and O2. Stimuli were shown for 15 seconds each and black screens were displayed for 15 seconds between each stimulus. As results, the brain waves at O1 responded sensitively by different background colors, followed by F4 and T4. Brain index such as 'RT', 'RA', 'RG', 'RSA', and 'RAHB' showed significant differences depending on the background color at O1, whereas 'RST' differed at F4. Yellow and blue backgrounds pair was the only stimuli that showed significant differences in six brain indices mentioned. Yellow background had higher value of 'RG' at O1 and higher 'RST' at F4, indicating yellow background enhanced concentration. Blue background activated 'RT', 'RA', 'RSA', 'RAHB' at O1, meaning blue background induced calm and stable state.

다중 구간 샘플링에 기반한 배경제거 알고리즘 (Background Subtraction Algorithm Based on Multiple Interval Pixel Sampling)

  • 이동은;최영규
    • 정보처리학회논문지:소프트웨어 및 데이터공학
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    • 제2권1호
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    • pp.27-34
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    • 2013
  • 배경제거는 동영상의 내용을 자동으로 분석하기 위한 매우 중요한 기술의 하나로 움직이는 객체를 검출하고 추적하기 위한 핵심 기술이다. 본 논문에서는 배경 모델과 함께 배경 영상을 제공하는 새로운 샘플링 기반의 배경제거 알고리즘을 제안한다. 제안된 방법에서는 움직임이 빠른 객체와 느린 객체를 동시에 처리하기 위해 다중 구간 샘플링 기법을 이용하여 배경 모델을 생성한다. 이러한 다중 구간 배경 모델들로부터 최선의 배경 모델을 만들기 위해 "신뢰도"를 사용한 것이 본 논문의 특징이다. 배경 제거 분야에서 다양한 모델을 병합하여 하나의 모델을 만들기 위해 신뢰도를 정의하여 사용한 경우는 현재까지 보고되지 않았다. 실험을 통해 제안된 방법이 다양한 속도의 객체가 존재하고 시간에 따른 그림자의 이동과 같은 환경 변화가 있는 응용에서도 안정적인 결과를 나타내는 것을 알 수 있었다.

Background-noise Reduction for Fourier Ptychographic Microscopy Based on an Improved Thresholding Method

  • Hou, Lexin;Wang, Hexin;Wang, Junhua;Xu, Min
    • Current Optics and Photonics
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    • 제2권2호
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    • pp.165-171
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    • 2018
  • Fourier ptychographic microscopy (FPM) is a recently proposed computational imaging method that achieves both high resolution (HR) and wide field of view. In the FPM framework, a series of low-resolution (LR) images at different illumination angles is used for high-resolution image reconstruction. On the basis of previous research, image noise can significantly degrade the FPM reconstruction result. Since the captured LR images contain a lot of dark-field images with low signal-to-noise ratio, it is very important to apply a noise-reduction process to the FPM raw dataset. However, the thresholding method commonly used for the FPM data preprocessing cannot separate signals from background noise effectively. In this work, we propose an improved thresholding method that provides a reliable background-noise threshold for noise reduction. Experimental results show that the proposed method is more efficient and robust than the conventional thresholding method.

충남 웅천에서 관측된 강수의 산성도 연구 (Acidity Analysis of Precipitation Occurred at Woongchon, Choongnam)

  • 이근준;정용승
    • 한국대기환경학회지
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    • 제12권2호
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    • pp.179-187
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    • 1996
  • Sampling of precipitation occurred at Woongchon in Choongnam from the period between May 1994 and April 1995 was made, and analysis on the data was carried out on observed pH values of the precipitations. It was found that weighted mean pH values were .sim. 4.8 and that acid rain occurred at the site of the Yellow Sea's coastal area. The results agree well with the earlier observations made at other sites of a background monitoring network. The annual values observed at the background monitoring sites were too low in comparison with the mean pH values (5.3 .sim. 5.9) obtained from urban stations of the Ministry of Environment. It was observed that values of pH in rain water often changed with time during the event of precipitation, and the low values usually depended on an airflow and a cyclone that originated in the source region.

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Background reduction by Cu/Pb shielding and efficiency study of NaI(TI) detector

  • Ramadhan, Revink A.;Abdullah, Khairi MS.
    • Nuclear Engineering and Technology
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    • 제50권3호
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    • pp.462-469
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    • 2018
  • The background spectrum of a $3^{{\prime}{\prime}}{\times}3^{{\prime}{\prime}}$ NaI(Tl) well-type scintillation SILENA detector was measured without shielding, in 6 cm thick lead shielding, and with 2 mm thick electrolytic copper covering the detector inside the lead shielding. The relative remaining background of the lead shield lined with copper was found to be ideal for low-level environmental radioactive spectroscopy. The background total count rate in the (20-2160 KeV) was reduced 28.7 times by the lead and 29 times by the Cu + Pb shielding. The effective reduction of background (1.04) by the copper mainly appeared in the energy range from X-ray up to 500 KeV, while for the total energy range the ratio is 1.01 relative to the lead only. In addition, a strong relation between the full-energy peak absolute efficiency and the detector well height was found using gamma-ray isotropic radiation point sources placed inside the detector well. The full-energy peak efficiency at a midpoint of the well (at 2.5 cm) is three times greater than that on the detector surface. The energy calibrations and the resolution of any single energy line are independent of the locations of the gamma source inside or outside of the well.

도심지 내 복층 저소음포장 설치에 따른 소음저감 사례연구 (A Case Study on Noise Reduction Effect of Two-layer Porous Asphalt Pavement in an Urban Area)

  • 정종석;소정락;이수형;양홍석
    • 한국도로학회논문집
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    • 제18권5호
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    • pp.49-56
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    • 2016
  • PURPOSES : In this study, noise reduction effect of a two-layer porous asphalt pavement was investigated through site measurement and computer simulation. METHODS : To examine noise reduction effect, a 3 km long quiet pavement was installed by removing previous normal pavement, which had a rather low porosity. The studied site was a high-rise apartment building surrounded by the quiet pavement and Seoul ring road with heavy traffic volume, indicating relatively high background noise. RESULTS : The measurement result before and after installing the quiet pavement showed a noise reduction effect of 4.3 dB(A) at a distance of 7.5 m from the road. After validating the accuracy of simulation using SoundPLAN, the reduction in SPL(sound pressure level) at the facades by the quiet pavement was predicted by considering five different road conditions generating traffic noise from each road or in the combination of the quiet pavement and Seoul ring road. In the case of no noise from Seoul ring road, noise reduction at the facades was 4.2 dB(A) on average for 702 housing units. With background noise from Seoul ring road, however, the average SPL decreased to 2.0 dB(A). Regarding subjective response of noise, the number of housing units with a noise reduction of over 3 dB(A) was 229 out of 706 units (approximately 32%). For 77 housing units, the noise reduction was between 1~3 dB(A), while it was less than 1 dB(A) for 400 housing units. CONCLUSIONS : The overall result indicates that the quiet pavement is useful to reduce noise evenly at low and high floors compared to noise barriers, especially in the urban situation where background noise is low.