• 제목/요약/키워드: low background

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중.저준위 방사성폐기물 처분 부지 내 배경 단열의 통계적 특성 분석 (Analysis of the statistical properties for the background fractures in the LILW disposal site of Korea)

  • 지성훈;박경우;김경수;김천수
    • 방사성폐기물학회지
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    • 제6권4호
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    • pp.257-263
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    • 2008
  • 중 저준위 방사성패기물 처분장 부지의 지하수 시스템을 개념화하기 위해 부지 내 유동성 배경 단열의 통계적 특성을 분석하였다. 이를 위해 부지 내 시추공에서 얻어진 시추공 로깅 자료의 배경 단열의 주향과 경사 자료를 분석하여 부지 내 배경 단열들을 4개의 단열군으로 분류하였다. 그리고 시추공에서의 수리 시험 결과로 얻어진 시추공 구간별 투수량계수 분포 자료로부터 배경 단열의 투수량계수 분포를 추정하였다. 각 단열군의 단열 크기 분포는 관찰된 단열 밀도와 지표지질조사 자료로부터 유추하였다. 이렇게 얻어진 배경 단열의 통계적 특성을 부지에서 관찰된 투수량계수 분포와 분석 된 통계적 특성을 이용하여 생성된 단열망 모형으로부터 계산된 투수량계수 분포를 비교하여 검증하였고, 검증 결과 관측치와 계산치가 비슷함을 확인하였다.

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배경소음이 다른 동일 건물내 사업장의 소음 수인한도 및 인지 정도에 관한 연구 (An study on the annoyance and loudness for the different background noises in complex building)

  • 이태강;장길수;김선우
    • KIEAE Journal
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    • 제10권5호
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    • pp.109-114
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    • 2010
  • There are many business in complex building, and recently noise claims have increased in those buildings. It is one of the most desirable methods reducing the noise level to establish the noise criteria considering the admittable noise level between the source and receiving room, which are to be derived from the subjective response in the real conditions. Because the degree of annoyance and loudness for the intruding noises in complex building could be changed with background noise level, it is suggested to be researched the relationship between the noise levels and subjective response. In this study, the subjective response for three different background levels in receiving business or rooms were investigated for the typical eight business noise source including aerobic music. The results can be summarized as follows. In conditions of low background noise level(40 dB(A)), there is a tendency of intentionally attention situation (listening) in a subjective test. The other hand in conditions of relatively high background noise level(50 dB(A)), there is a unconscious situation (heraing). As the degree of moderately heard or annoyed in SD rating scale means that the noise is easily recognized in neighboring shops, usually the limit of noise criteria were decided on this rating point, so it will be reasonable to be adopted the criteria rating scale as slight heard or annoyed degree (SD criteria 3).

Effect of Low-fat Diet on Breast Cancer Survival: a Meta-analysis

  • Xing, Mei-Yuan;Xu, Su-Zhen;Shen, Peng
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권3호
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    • pp.1141-1144
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    • 2014
  • Background: Even though many studies have examined the possible effect of low-fat diet on breast cancer survival, the relationship remains unclear. Objectives: To summarize the current evidence about the effect of post-diagnostic low-fat diet on recurrence and all-cause mortality of breast cancer. Methods: We conducted a search of Pubmed, Embase, Web of Science, and Cochrane Library and as a result two randomized controlled trials (RCT) and one large multi-center prospective cohort study with 9,966 breast cancer patients were included in this report. Results: Post-diagnostic low-fat diet reduced risk of recurrence of breast cancer by 23% (HR=0.77, 95%CI 0.63 to 0.94, P=0.009) and all cause mortality of breast cancer by 17% (HR=0.83, 95%CI 0.69 to 1.00, P=0.05). Conclusions: This meta-analysis suggested the post-diagnostic low-fat diet can improve breast cancer survival by reducing risk of recurrence. However, more trials of the relationship between low-fat diet and allcause mortality of breast cancer are still needed.

요통 환자의 운동행위 변화단계에 미치는 영향 요인 (Influencing Factors on the Stages of Change of Exercise in Patients with Low Back Pain)

  • 이혜경;신은희;황선미
    • 재활간호학회지
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    • 제17권2호
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    • pp.72-80
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    • 2014
  • Purpose: The objective of this study was to analyze the factors affecting the stages of exercise behaviors changes of low back pain patients. Methods: The participants in this study were 220 low back pain patients who have been treated by therapeutic exercise or had the exercise treatment under the doctor's advice. The tools used for this study were the stages of exercise behavior change, intrinsic motivation questionnaires, and physical activity social support scale (PASS). Results: The group that did exercise (preparation stage, maintenance stage, action stage) was 75.9% but the group that did not exercise (precontemplation stage, contemplation stage) was 24.1%. Social supports from family members and friends and motivation affected the exercise behaviors changes. And 34.6% of the exercise behavior change can be explained by the social support (family, friend) and motivation. Conclusion: There were two recommendations for maintaining the exercise behaviors of low back pain patients based on theoretical background. First, we recommended more exercise programs which reinforce social supports from family and friend for constant exercise behaviors of low back pain patients. Second, more exercise programs for the low back pain patients who have similar health goals or problems were needed for motivating them to join the exercise programs.

Low-Level Laser Therapy including Laser Acupuncture for Non-Specific Chronic Low Back Pain : Protocol for a Systematic Review

  • Yeum, Hyewon;Nam, Dongwoo
    • Journal of Acupuncture Research
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    • 제36권4호
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    • pp.251-255
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    • 2019
  • Background: Low-level laser therapy (LLLT) including laser acupuncture (LA) has been widely used to treat chronic low back pain (CLBP), but there is no critically appraised evidence of the potential benefits. The purpose of this protocol for a systematic review was to enable the evaluation of the effectiveness of LLLT including LA for non-specific CLBP to identify the potential benefits. Methods: The electronic databases MEDLINE (PubMed), Embase (Ovid), the Cochrane Central Register of Controlled Trials (CENTRAL), Korean medical databases (KoreaMed, KMBASE, KISS, NDSL, KISTI, OASIS), the Chinese database (CNKI), and Japanese databases (CiNII, J-STAGE) are recommended. Results: Randomized controlled trials in LLLT including LA should be included in the searches. All data synthesis and subgroup analyses should be conducted using a Review Manager software. The Cochrane risk of bias tool can be used to evaluate methodological quality of the studies. A risk ratio or mean difference with a 95% confidence interval will show the effects of LLLT including LA. Conclusion: The primary outcome would be pain intensity and functional status/disability due to low back pain. The secondary outcome would be a global measurement of recovery or improvement, quality of life and adverse event.

이미지 내의 텍스트 데이터 인식 정확도 향상을 위한 멀티 모달 이미지 처리 프로세스 (Multi-modal Image Processing for Improving Recognition Accuracy of Text Data in Images)

  • 박정은;주경돈;김철연
    • 데이타베이스연구회지:데이타베이스연구
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    • 제34권3호
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    • pp.148-158
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    • 2018
  • 광학 문자 인식(OCR)은 텍스트를 포함한 이미지에서 텍스트 영역을 인식하고 이로부터 텍스트를 추출하는 기술이다. 전체 텍스트 데이터 중 상당히 많은 텍스트 정보가 이미지에 포함되어 있기 때문에 OCR은 데이터 분석 분야에 있어 중요한 전처리 단계를 담당한다. 대부분의 OCR 엔진이, 흰 바탕의 검정 글씨의 단순한 형태를 가진 이미지와 같은, 텍스트와 배경의 구분이 뚜렷한 저 복잡도 이미지에 대해서는 높은 인식률을 보이는 반면, 텍스트와 배경의 구분이 뚜렷하지 않은 고 복잡도 이미지에 대해서는 저조한 인식률을 보이기 때문에, 인식률 개선을 위해 입력 이미지를 OCR 엔진이 처리하기 용이한 이미지로 변형하는 전처리 작업이 필요하게 된다. 따라서 본 논문에서는 OCR 엔진의 정확성 증대를 위해 텍스트 라인별로 이미지를 분리하고, 영상처리 기법 기반의 CLAHE 모듈과 Two-step 모듈을 병렬적으로 수행하여 텍스트와 배경 영역을 효율적으로 분리한 후 텍스트를 인식한다. 이어서 두 모듈의 결과 텍스트에 대하여 N-gram방법과 Hunspell 사전을 결합한 알고리즘으로 인식률을 비교하여 가장 높은 인식률의 결과 텍스트를 최종 결과물로 선정하는 방법론을 제안한다. 대표적인 OCR 엔진인 Tesseract와 Abbyy와의 다양한 비교 실험을 통해 본 연구에서 제안하는 모듈이 복잡한 배경을 가진 이미지에서 가장 정확한 텍스트 인식률을 보임을 보였다.

Bayesian MCMC를 이용한 저수량 점 빈도분석: I. 이론적 배경과 사전분포의 구축 (At-site Low Flow Frequency Analysis Using Bayesian MCMC: I. Theoretical Background and Construction of Prior Distribution)

  • 김상욱;이길성
    • 한국수자원학회논문집
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    • 제41권1호
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    • pp.35-47
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    • 2008
  • 저수분석(low flow analysis)은 수자원공학에서 중요한 분야 중 하나이며, 특히 저수량 빈도분석(low flow frequency analysis)의 결과는 저수(貯水)용량의 설계, 물 수급계획, 오염원의 배치 및 관개와 생태계의 보존을 위한 수량과 수질의 관리에 중요하게 사용된다. 그러므로 본 연구에서는 저수량 빈도분석을 위한 점 빈도분석을 수행하였으며, 특히 빈도분석에 있어서의 불확실성을 탐색하기 위하여 Bayesian 방법을 적용하고 그 결과를 기존에 사용되던 불확실성 탐색방법과 비교하였다. 본 논문의Ⅰ편에서는 Bayesian 방법 중 사전분포(prior distribution)와 우도함수(likelihood function)의 복잡성에 상관없이 계산이 가능한 Bayesian MCMC(Bayesian Markov Chain Monte Carlo) 방법과 Metropolis-Hastings 알고리즘을 사용하기 위한 여러 과정의 이론적 배경과 Bayesian 방법에서 가장 중요한 요소인 사전분포를 구축하고 이를 비교 및 평가하였다. 고려된 사전분포는 자료에 기반하지 않은 사전분포와 자료에 기반한 사전분포로써 두 사전분포를 이용하여 Metropolis-Hastings 알고리즘을 수행하고 그 결과를 비교하여 저수량 빈도분석에 합리적인 사전분포를 선정하였다. 또한 알고리즘의 수행과정에서 필요한 제안분포(proposal distribution)를 적용하여 그에 따른 알고리즘의 효율성을 채택률(acceptance rate)을 산정하여 검증해 보았다. 사전분포의 분석 결과, 자료에 기반한 사전분포가 자료에 기반하지 않은 사전분포보다 정확성 및 불확실성의 표현에 있어서 우수한 결과를 제시하는 것을 확인할 수 있었고, 채택률을 이용한 알고리즘의 효용성 역시 기존 연구자들이 제시하였던 만족스러운 범위를 가지는 것을 알 수 있었다. 최종적으로 선정된 사전분포는 본 연구의 II편에서 Bayesian MCMC방법의 사전분포로 이용되었으며, 그 결과를 기존 불확실성의 추정방법의 하나인 2차 근사식을 이용한 최우추정(maximum likelihood estimation)방법의 결과와 비교하였다.

THE CONTRIBUTION TO THE EXTRAGALACTIC γ-RAY BACKGROUND BY HADRONIC INTERACTIONS OF COSMIC RAYS PRODUCING EUV EMISSION IN CLUSTERS OF GALAXIES

  • KUO PING-HUNG;BOWYER STUART;HWANG CHORNG- YUAN
    • 천문학회지
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    • 제37권5호
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    • pp.597-600
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    • 2004
  • A substantial number of processes have been suggested as possible contributors to the extragalactic $\gamma$-ray background (EGRB). Yet another contribution to this background will be emission produced in hadronic interactions of cosmic-ray protons with the cluster thermal gas; this class of cosmic rays (CRs) has been shown to be responsible for the EUV emission in the Coma Cluster of galaxies. In this paper we assume the CRs in the Coma Cluster is prototypic of all clusters and derive the contribution to the EGRB from all clusters over time. We examine two different possibilities for the scaling of the CR flux with cluster size: the number density of the CRs scale with the number density of the thermal plasma, and alternatively, the energy density of the CRs scale with the energy density of the plasma. We find that in all scenarios the EGRB produced by this process is sufficiently low that it will not be observable in comparison with other mechanisms that are likely to produce an EGRB.

LOW-LEVEL RADIO EMISSION FROM RADIO GALAXIES AND IMPLICATIONS FOR THE LARGE SCALE STRUCTURE

  • KRISHNA GOPAL;WIITA PAUL J.;BARAI PARAMITA
    • 천문학회지
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    • 제37권5호
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    • pp.517-525
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    • 2004
  • We present an update on our proposal that during the 'quasar era' (1.5 $\le$ z $\le$ 3), powerful radio galaxies could have played a major role in the enhanced global star-formation, and in the widespread magnetization and metal pollution of the universe. A key ingredient of this proposal is our estimate that the true cosmological evolution of the radio galaxy population is likely to be even steeper than what has been inferred from flux-limited samples of radio sources with redshift data, when an allowance is made for the inverse Compton losses on the cosmic microwave background which were much greater at higher redshifts. We thus estimate that a large fraction of the clumps of proto-galactic material within the cosmic web of filaments was probably impacted by the expanding lobes of radio galaxies during the quasar era. Some recently published observational evidence and simulations which provide support for this picture are pointed out. We also show that the inverse Compton x-ray emission from the population of radio galaxies during the quasar era, which we inferred to be largely missing from the derived radio luminosity function, is still only a small fraction of the observed soft x-ray background (XRB) and hence the limit imposed on this scenario by the XRB is not violated.

THE DIFFUSE NEAR-INFRARED BACKGROUND SPECTRUM FROM AKARI

  • Kohji, Tsumura;Toshio, Matsumoto;Shuji, Matsuura;Itsuki, Sakon;Takehiko, Wada
    • 천문학논총
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    • 제32권1호
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    • pp.321-326
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    • 2017
  • We analyzed spectral data of the astrophysical diffuse emission obtained with the low-resolution spectroscopy mode on the AKARI InfraRed Camera (IRC) in the $1.8-5.3{\mu}m$ wavelength region. Advanced reduction methods specialized for slit spectroscopy of diffuse sky spectra have been developed, and a catalog of 278 spectra of the diffuse sky covering a wide range of Galactic and ecliptic latitudes was constructed. Using this catalog, two other major foreground components, the zodiacal light (ZL) and the diffuse Galactic light (DGL), were separated and subtracted by taking correlations with ZL brightness estimated by the DIRBE ZL model and with the $100{\mu}m$ dust thermal emission, respectively. The isotropic emission was interpreted as the extragalactic background light (EBL), which shows significant excess over the integrated light of galaxies at <$4{\mu}m$.