• 제목/요약/키워드: underestimation

검색결과 344건 처리시간 0.029초

역동적 유방 자기공명 영상 및 확산 강조영상을 이용한 관상피내암종 저평가 수술전 예측 (Preoperative Prediction of Ductal Carcinoma in situ Underestimation of the Breast using Dynamic Contrast Enhanced and Diffusion-weighted Imaging)

  • 박미나;김은경;김민정;문희정
    • Investigative Magnetic Resonance Imaging
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    • 제17권2호
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    • pp.101-109
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    • 2013
  • 목적: 초음파 유도 하 중심부 침생검으로 진단된 2 cm 이상의 관상피내암종 저평가 수술 전 예측에 역동적 유방 자기공명 영상 및 확산강조영상의 역할을 규명하고자 한다. 대상과 방법: 14 gauge침을 이용한 초음파 유도 하 중심부 침생검을 통해 관상피내암종으로 진단된 22명의 환자를 대상으로 하였다. 환자는 조직병리 결과에 의거하여 관상피내암종 저평가 유무에 따라 두 군으로 나뉘었다. 모든 환자에서 역동적 유방 자기공명 영상 및 확산강조영상을 포함한 3 테슬라 유방 자기공명 영상을 획득하였다. 생검으로 확인된 악성 종괴에 대해, 병변의 형태 (종괴 혹은 비종괴), 조영 증강 형태, 조영 증강 최고점, 및 현성 확산 계수를 CADstream 소프트웨어를 이용하여 획득 하였으며, Fisher's exact test및 Mann Whitney test 이용하여 이 항목을 비교, 분석하였다. 결과: 총 22명의 환자 중 8명의 환자가 저평가 군으로 분류되었다. 병변의 형태 및 조영증강 형태는 두 군의 통계학적 차이가 없었다 (P values = 1.000 및 0.613). 조영 증강 최고점의 중앙값은 저평가 군에서 159.5% 로 저평가 되지 않은 군의 133.5% 보다 높았으나 통계학적 유의한 차이를 보이지 않았다 (P value = 0.413). 저평가 군의 현성 확산 계수는 $1.26{\times}10^{-3}mm^2/sec$로 저평가 되지 않은 군의 $1.35{\times}10^{-3}mm^2/sec$ 보다 낮았다 (P value = 0.094). 결론: 현성 확산 계수는 초음파 유도한 중심부 침생검에 의한 관상피내암종 저평가 수술 전 예측에 도움이 될 가능성 있으며 추후 전향적 연구를 통해 이 연구 결과를 확인하는 것이 필요하겠다.

국내 잔류농약 residue definition과 관련된 식이노출의 과소평가 (Underestimation of Dietary Exposure to Pesticide Residues in Relation to Residue Definition in South Korea)

  • 이미경
    • 한국식품위생안전성학회지
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    • 제35권5호
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    • pp.452-458
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    • 2020
  • 본 연구는 식물성 식품에 대한 잔류농약의 국내와 코덱스의 residue definition 비교를 통해 국내에서 식이노출 과소평가의 가능성이 있는 농약성분을 파악하고 더 나아가 식이노출 과소평가가 위해성 평가에 미치는 영향에 대해 우선적으로 검토가 필요한 농약성분을 알아내고자 하였다. 연구결과, 국내와 코덱스의 residue definition 정보로부터 식이노출 과소평가의 가능성이 있는 44종의 농약성분이 파악되었다. 이들 성분 중 농약성분의 ADI값, 국내 MRL 정보 및 대사물질의 독성학적 정보에 근거하여 다음의 24종 농약성분이 식이노출 과소평가가 위해성 평가에 미치는 영향에 대해 우선적으로 검토가 필요한 것으로 나타났다: acibensolar-S-methyl, chlorfenapyr, chlorothalonil, cyantraniliprole, cyclaniliprole, cyflumetofen, dithiocarbamates, fenamidone, fenpyroximate, fluazifop-P-butyl, fluopicolide, flupyradifuron, fluxapyroxad, glyphosate, hexythiazox, isoprothiolane, isopyrazam, myclobutanil, penthiopyrad, propiconazole, spinetoram, spiromesifen, spirotetramat, trifloxystrobin. 더 나아가 chlorfenapyr, chlorothalonil, dithiocarbamates, fenamidone은 대사물질의 독성이 더 커서 특히 우선적으로 검토가 요구되는 것으로 판단된다. 본 연구는 식품 중 잔류농약에 대한 국내 위해성 평가방법의 개선을 위해 활용될 수 있을 것으로 기대된다.

비부착 긴장재의 응력산정을 위한 극한강도 설계식의 평가 (Evaluation of Ultimate Strength Design Equations for Stress Calculation of Unbonded Tendons)

  • 임재형;문정호;이리형
    • 콘크리트학회논문집
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    • 제11권3호
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    • pp.113-122
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    • 1999
  • The present study is to investigate the possibility of overestimation or underestimation when the ACI Code equations are used to evaluate the unbonded tendon stress. An experimental program was planned with 6 beams which divided into two groups. Each group consisted of 3 beams to check the possibility of overestimation or underestimation of unbonded tendon stress. The experimental results were also compared with various design equations including the one proposed by Moon and Lim. It was proven that the ACI Code equations may overestimate or underestimate the unbonded tendon stress in certain cases.

입원한 조현병 환자의 신체이미지 왜곡 (Body Image Distortion among Inpatients with Schizophrenia)

  • 김성진;문석우;김대호
    • 생물정신의학
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    • 제19권4호
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    • pp.211-218
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    • 2012
  • Objectives Body image distortion is found in eating disorder and obesity and there are some evidence that schizophrenia is associated with body image distortion. This study sought to find whether schizophrenic patients report more body image distortion than healthy individuals and whether it is related with symptomatology. Methods A total of 88 inpatients with schizophrenia and 88 healthy controls were recruited. Weight, height, and body image accuracy were assessed in all participants, and assessment of mood, psychotic symptom severity and self-esteem, and personal and social performance scale were conducted. Results The patients with schizophrenia had higher Body Mass Index (p < 0. 001) and underestimated their body size more than controls (26.14% vs. 5.13%, p < 0.001). Multiple regression analysis showed that lower depressive symptoms and higher scores of general psychopathology predicted underestimation of body size. Conclusion Weight gain and metabolic syndrome are common adverse events of pharmacological treatment of schizophrenia. Thus, underestimation of body size among patients with schizophrenia may interfere with effort to lose weight or seek weight reduction programs. Clinicians need to consider possible unterestimation of underestimation of body size in patients whose general symptomatology is severe.

Combined effect of the horizontal components of earthquakes for moment resisting steel frames

  • Reyes-Salazar, Alfredo;Juarez-Duarte, Jose A.;Lopez-Barraza, Arturo;Velazquez-Dimas, Juan I.
    • Steel and Composite Structures
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    • 제4권3호
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    • pp.189-209
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    • 2004
  • The commonly used seismic design procedures to evaluate the maximum effect of both horizontal components of earthquakes, namely, the Square Root of the Sum of the Squares (SRSS) and the 30-percent (30%) combination rules, are re-evaluated. The maximum seismic responses of four three-dimensional moment resisting steel frames, in terms of the total base shear and the axial loads at interior, lateral and corner columns, are estimated as realistically as possible by simultaneously applying both horizontal components. Then, the abovementioned combination rules and others are evaluated. The numerical study indicates that both, the SRSS rule and the 30% combination method, may underestimate the combined effect. It is observed that the underestimation is more for the SRSS than for the 30% rule. In addition, the underestimation is more for inelastic analysis than for elastic analysis. The underestimation cannot be correlated with the height of the frames or the predominant period of the earthquakes. A basic probabilistic study is performed in order to estimate the accuracy of the 30% rule in the evaluation of the combined effect. Based on the results obtained in this study, it is concluded that the design requirements for the combined effect of the horizontal components, as outlined in some code-specified seismic design procedures, need to be modified. New combination ways are suggested.

The effect of the number of subintervals upon the quantification of the seismic probabilistic safety assessment of a nuclear power plant

  • Ji Suk Kim;Man Cheol Kim
    • Nuclear Engineering and Technology
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    • 제55권4호
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    • pp.1420-1427
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    • 2023
  • Seismic risk has received increased attention since the 2011 Fukushima accident in Japan. The seismic risk of a nuclear power plant is evaluated via seismic probabilistic safety assessment (PSA), for which several methods are available. Recently, the discrete approach has become widely used. This approximates the seismic risk by discretizing the ground motion level interval into a small number of subintervals with the expectation of providing a conservative result. The present study examines the effect of the number of subintervals upon the results of seismic risk quantification. It is demonstrated that a small number of subintervals may lead to either an underestimation or overestimation of the seismic risk depending on the ground motion level. The present paper also provides a method for finding the boundaries between overestimation and underestimation regions, and illustrates the effect of the number of subintervals upon the seismic risk evaluation with an example. By providing a method for determining the effect of a small number of subintervals upon the results of seismic risk quantification, the present study will assist seismic PSA analysts to determine the appropriate number of subintervals and to better understand seismic risk quantification.

우리나라 성인 여성의 체형인식왜곡 영향요인 (Prevalence and Factors Affecting Body Shape Misperception among Korean Adult Women)

  • 정미영;김선호
    • 여성건강간호학회지
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    • 제22권3호
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    • pp.162-169
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    • 2016
  • Purpose: This study was done to investigate the prevalence and factors affecting body shape misperception among Korean adult women. Methods: We analyzed raw data from the fourth Korean Longitudinal Survey of Women and Families, for 7,658 women over 20 years of age. For the multiple logistic regression model, the dependent variable was existence of misperception (yes/no). Results: The prevalence of body shape misperception was 42.6% (overestimation 6.5%, underestimation 36.1%). Multiple logistic regression analysis revealed that age, education level, marital status, economic status and BMI were significantly associated with body shape underestimation. Education level and BMI were significantly associated with body shape overestimation. Conclusion: An effective obesity intervention program for women must reflect and monitor body shape perception as well as BMI.

다경로인 경우 Eigen 구조를 이용하는 공간 스펙트럼 추정 알고리듬의 성능비교 (Performance Comparisons of Eigenstructure Based Spatial Spectrum Estimation Algorithms in a Multipath Environment)

  • 이충용;차일환;윤대희
    • 대한전자공학회논문지
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    • 제25권12호
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    • pp.1522-1531
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    • 1988
  • The purpose of this paper is to explain eigenstructure based spatial spectrum estimation algorithms computing better estimates than the other approaches. Also, as an approach to overcome performance degradations in a multipath environments, the notion of forward and backwark spatial smoothing is discussed. Intensive simulation results,which include the comparisons of the eigenbased spatial spectral estimation algorithms in the situations of faulty estimation of the number of signals, are presented. The simulation results have shown that overestimation of the number of signals is more desirable than underestimation in using EV (Eigen Vector) and MUSIC (Multiple Signal Classification) algorithms and that underestimation of the number of signals is better strategy than overestimation in using eigenstructure based LP(Linear Prediction) algorithms.

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