• 제목/요약/키워드: Risk Probability

검색결과 1,139건 처리시간 0.031초

Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

  • Cho, Oyeon;Chun, Mison;Park, Sung Ho;Oh, Young-Taek;Kim, Mi-Hwa;Park, Hae-Jin;Nam, Sang Soo;Heo, Jaesung;Noh, O Kyu
    • Radiation Oncology Journal
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    • 제31권1호
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    • pp.12-17
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    • 2013
  • Purpose: Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. Materials and Methods: From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Results: Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p < 0.001). Mean parotid dose of both glands ${\geq}20$ Gy were observed in 15 (28.3%) for CF and in 0 (0.0%) for MF. The whole brain percentage volumes receiving >98% of prescribed dose were 99.7% for CF and 99.5% for MF. Conclusion: Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

불확실성을 고려한 통합유역모델링 (Integrated Watershed Modeling Under Uncertainty)

  • 함종화;윤춘경;다니엘 라욱스
    • 한국농공학회논문집
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    • 제49권4호
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    • pp.13-22
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    • 2007
  • The uncertainty in water quality model predictions is inevitably high due to natural stochasticity, model uncertainty, and parameter uncertainty. An integrated modeling system under uncertainty was described and demonstrated for use in watershed management and receiving-water quality prediction. A watershed model (HSPF), a receiving water quality model (WASP), and a wetland model (NPS-WET) were incorporated into an integrated modeling system (modified-BASINS) and applied to the Hwaseong Reservoir watershed. Reservoir water quality was predicted using the calibrated integrated modeling system, and the deterministic integrated modeling output was useful for estimating mean water quality given future watershed conditions and assessing the spatial distribution of pollutant loads. A Monte Carlo simulation was used to investigate the effect of various uncertainties on output prediction. Without pollution control measures in the watershed, the concentrations of total nitrogen (T-N) and total phosphorous (T-P) in the Hwaseong Reservoir, considering uncertainty, would be less than about 4.8 and 0.26 mg 4.8 and 0.26 mg $L^{-1}$, respectively, with 95% confidence. The effects of two watershed management practices, a wastewater treatment plant (WWTP) and a constructed wetland (WETLAND), were evaluated. The combined scenario (WWTP + WETLAND) was the most effective at improving reservoir water quality, bringing concentrations of T-N and T-P in the Hwaseong Reservoir to less than 3.54 and 0.15 mg ${L^{-1}$, 26.7 and 42.9% improvements, respectively, with 95% confidence. Overall, the Monte Carlo simulation in the integrated modeling system was practical for estimating uncertainty and reliable in water quality prediction. The approach described here may allow decisions to be made based on probability and level of risk, and its application is recommended.

신경모세포종 -15년간 한 병원에서의 임상적 경험- (Neuroblastoma - Experience in One Center -)

  • 김대연;김성철;김인구
    • Advances in pediatric surgery
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    • 제11권2호
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    • pp.99-106
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    • 2005
  • Neuroblastoma treatment remains challenging, but treatment has become more effective due to the establishment of clinical and biological variables that determine prognostic risks. Initially, stage and age were the prime determinants of survival used in clinical practice. Risk-based therapy currently is the hallmark of neuroblastoma treatment. This study reviews one center's experience with the management of neuroblastoma. Sixty-three patients with neuroblastoma were treated from 1989 to 2003. All patients were graded according to the International Neuroblastoma Staging System (INSS) at diagnosis. There were 37 boys and 26 girls. The median age was 2.14 years (range, 33 days-10.2years). The primary site was the adrenal gland in 47, dumbbell shape extending into spinal canal in 6, retroperitoneum in 5, mediastinum in 3, and other sites in 2. The probability of 5-year overall survival (OS) and event free survival (EFS) were 46.7 % and 44.2 % by Kaplan-Meier method. According to INSS, there were stage 1 in 2 cases, stage 2 in 5, stage 3 in 12, stage 4 in 42, and stage 4s in 2. There were statistically significant differences in the survival rates between patients with stage1, 2 and stage 3, 4(P<0.05). For the stage 3 and 4, the extents of surgical resection, determined from the operative records and pathologies, were complete resection in 17 cases, minimal residual in 15, and partial resection 11, and the 5-year OS rate was 57.8, 51.4, and 13.6 %, respectively. There is a trend toward higher OS with more complete resection (P<0.05). We conclude that age and stage at diagnosis are prognostic factors, and complete excision of the primary tumor can provide better prognosis for patients with stage 3 and 4 neuroblastoma.

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송전선로의 이용률 평가 및 합리적 운영에 관한 연구 (A Study on Utilization Ratio and Operation of Transmission Lines)

  • 김동민;배인수;조종만;김진오
    • 대한전기학회논문지:전력기술부문A
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    • 제55권10호
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    • pp.426-432
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    • 2006
  • This paper describes the concepts of Static Line Rating (SLR) and Dynamic Line Rating (DLR) and the computational methods to demonstrate them. Calculation of the line capacity needs the heat balance equation which is also used for computing the reduced tension in terms of line aging. SLR is calculated with the data from the worst condition of weather throughout the year. Even now, the utilization ratio is obtained from this SLR data in Korea. DLR is the improved method compared to SLR. A process for DLR reveals not only improved line ratings but also more accurate allowed line ratings based on line aging and real time conditions of weather. In order to reflect overhead transmission line aging in DLR, this paper proposes the method that considers the amount of decreased tension since the lines have been installed. Therefore, the continuous allowed temperature for remaining life time is newly acquired. In order to forecast DLR, this paper uses weather forecast models, and applies the concept of Thermal Overload Risk Probability (TORP). Then, the new concept of Dynamic Utilization Ratio (DUR) is defined, replacing Static Utilization Ratio (SUR). For the case study, the two main transmission lines which are responsible for the north bound power flow in the Seoul metropolitan area are chosen for computing line rating and utilization ratio. And then line rating and utilization ratio are analyzed for each transmission line, so that comparison of the present and estimated utilization ratios becomes available. Finally, this paper proves the validity of predictive DUR as the objective index, with simulations of emergency state caused by system outages, overload and so on.

Determinants of Shopping Experience for Mall Shoppers: Empirical Investigation in an Emerging City of Raipur (India)

  • Singh, Harvinder;Prashar, Sanjeev;Agarwal, Rashmi;Sharma, Tarun Kumar
    • 아태비즈니스연구
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    • 제5권1호
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    • pp.13-21
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    • 2014
  • Shopping malls have become key players in the Indian retail space. Even in upcoming Indian towns, malls have been mushrooming. Raipur, the capital city of the Indian state of Chhattisgarh has witnessed the growth over the last few years. However, this unplanned growth of malls in cities is expected to lead to oversupply of mall space in the near future, making things difficult for mall developers. The study is an attempt to identify appropriate strategies for mall developers to iron out such kinks. This paper presents 'shopping experience' as a tool to compete, succeed and explore its composition in terms of its constituent factors. The paper uses Exploratory Factor Analysis (EFA) on a non-probability sample of 350 respondents. It condenses a set of twenty-two mall variables into five factors that directly influence the shopping experience. These factors included ambience, infrastructure, marketing focus, convenience and safety and security. In terms of significance, shoppers assigned different weightage to each of these factors. The study shed light on interesting insights regarding the expectations of mall shoppers in the city of Raipur. The results though interesting, may be extended to different social, economic and geographic contexts to check the universality. While strategizing, mall developers must assign proportionate effort on the factors based on the respective contribution to shopping experience. In light of intensifying competition in Raipur, the study is significant for future prospects of malls. In the absence of a scientific and objective basis, the developers run risk of making wrong investment and management decisions. This paper is a useful addition to the body of knowledge on management of shopping malls in India and is unique in terms of its focus on mall shoppers in the smaller Indian cities like Raipur.

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연령에 따른 교육수준과 만성질환의 관계 (Differential Effects of Educational Attainment on Chronic Diseases with Age)

  • 이민아
    • 한국인구학
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    • 제34권1호
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    • pp.179-198
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    • 2011
  • 본 논문의 목적은 연령과 교육수준이 한국인의 만성질환에 미치는 영향을 분석하는 데 있다. 이를 위해 한국노동연구원이 2006년에 수집한 '고령화연구패널조사(KLoSA: Korean Longitudinal Study of Ageing)'에 참여한 45세 이상의 한국인을 분석하였다. 분석결과는 먼저 연령과 만성질환이 비선형 관계를 갖고 있음을 보여준다. 연령이 증가함에 따라 응답자가 만성질환을 앓고 있을 확률도 증가하나 약 74세를 기준으로 다시 감소한다. 또한 이러한 연령과 만성질환의 관계는 교육수준에 따라 다르게 나타났다. 교육수준이 낮을수록 상대적으로 이른 나이에 만성질환이 발현하여 70대 초까지 상대적으로 만성질환에 노출될 확률이 높게 나타난다. 그러나 이러한 교육수준에 따른 건강격차는 수렴현상(convergence)을 보이다가 70대 초반 이후부터 역전되어 다시 분기(divergence)한다. 즉, 고령층에서는 오히려 교육수준이 높을수록 만성질환을 가질 확률이 높게 나타나는 것이다. 이러한 결과는 교육수준이 낮은 사람들이 만성질환에 상대적으로 더 젊은 나이에 노출되고 결국에는 이른 사망으로 이어질 수 있다는 점을 함의한다.

산업별 특성에 따른 소요공수 규모 산정 모델 연구 (A Study on the Scale Effort Estimation Model based on Industry Characteristics)

  • 곽송해;박구락;김동현
    • 디지털융복합연구
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    • 제14권11호
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    • pp.233-240
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    • 2016
  • 정보시스템 개발 프로젝트는 다양한 리스크 요소로 인하여 많은 비용이 발생하는 구조를 가지고 있다. 일반적으로 정보시스템 소프트웨어 프로젝트가 납기 내에 성공적으로 이루어질 확률은 매우 낮아 프로젝트 실패를 막는 주요한 요인인 정형화된 비용에 대한 예측이 필요하다. 그러나 대부분의 프로젝트 규모 산정 시 산정 기준의 객관성이 부족하며, 프로젝트 수행 중 베이스라인의 관리가 제대로 이루어지지 않고 있는 실정이다. 이에 본 논문에서는 정보시스템 개발 프로젝트 초기에 현장에서 실용적이지 못한 기법의 한계를 극복하고자 방법론 기반으로 개발에 소요되는 공수를 산정하는 모델을 제안한다. 이러한 융복합적인 제안 모델을 통하여 정보시스템 개발 사업에서 소요되는 공수와 비용을 추정하는데 간단하게 활용할 수 있는 도구가 될 것으로 기대된다.

Analysis of premature death of Sprague-Dawley rats in carcinogenicity studies

  • Son, Woo-Chan;Kim, Bae-Hwan
    • 대한수의학회지
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    • 제44권3호
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    • pp.373-378
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    • 2004
  • To help the interpretation of causes of death, it is critical that the background incidence of factors contributing to death be recorded and archived. Information was gathered from the control groups of 19 rat carcinogenicity studies. All cases of death occurring within the 2-year period were reviewed. Out of 1124 males and 1084 females, 720 male (64.1%) and 689 female (63.6%) decedents were recorded. There was no difference in the probability of survival between two sexes. Analysis of factors contributing to death revealed that 400 males (48.7%) had neoplastic changes, 189 males (23.0%) had non-neoplastic lesions, and 232 males (28.3%) died from unknown causes. In females, these figures were 627 (76.4%), 62 (7.6%) and 132 (16.0%), for neoplastic, non-neoplastic and unknown findings, respectively. It could be suggested that the risk of death by non-neoplastic reasons was higher in the males than in the females, whereas females were more likely to be affected by tumours. In the neoplastic causes of death, pituitary tumours were the most common in both sexes, followed by mammary tumours in females, and haemopoietic tumours in males. In non-neoplastic cause of death, renal diseases were the most common in both sexes, followed by skin diseases and cardiovascular diseases in males, and skin diseases and poditis in males. A relatively large number of animals (28.3% in males and 16.0% in females) were found dead, without any significant clinical or histologically identifiable cause. Most of the animals with pituitary tumours were killed in extremis and the proportion of females (70.1%) being greater than males (46.8%). There were no case which died by accident, and also only minimal incidence which died by bleeding procedures.

유연성 다중 회귀 모델을 활용한 보행자 이상 행동 예측 모델 연구 (Study on abnormal behavior prediction models using flexible multi-level regression)

  • 정유진;윤용익
    • Journal of the Korean Data and Information Science Society
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    • 제27권1호
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    • pp.1-8
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    • 2016
  • 최근 강력 범죄 및 우발 범죄가 끊이지 않고 있으면서 사회적 불안감이 고조되고 있다. 이에 따라 방범용 카메라, CCTV (Closed Circuit Television)가 범죄 증거 확보와 치안을 위해 사용되고 있다. 그러나 CCTV는 주로 사후 처리 기능으로 사용하고 있으며 사전에 범죄를 예방하기는 힘들다. 본 연구에서는 CCTV로부터 수집된 보행자 데이터를 이용하여 객체의 행동을 분석하고 위험 행동 여부를 추정하기 위한 유연성 다중 회귀 모델을 제안한다. 유연성 다중 회귀 모델은 필터링, 상황분석, 예측 단계로 구성되어 있다. 먼저 보행자에 대한 환경과 상황에 대해 필터링한 후 상황분석에 대한 정보를 구축하고 관찰 객체에 이상 행동이 결정된다. 마지막으로 연관분석을 통해 객체의 행동이 예측되어 위협 상황을 통지한다. 이를 통해 다중 지역에서 객체의 행동을 추적하여 객체 행동의 위험여부를 알 수 있으며, 행동 예측을 통해 범죄 발생을 예측 가능하다.

2급 지적 장애를 가진 환자의 SDA 개념을 적용한 전악 수복 증례 (Full mouth rehabilitation of an oligodontia patient with intellectual disability based on shortened dental arch concept: a case report)

  • 유재욱;허성주;김성균;곽재영
    • 대한치과보철학회지
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    • 제50권4호
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    • pp.330-335
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    • 2012
  • Shortened dental arch(SDA) 개념은 여러 현실적인 이유로 적절한 대안이 없을 경우 제 2 소구치까지만 수복이 이루어져도 안정적인 교합과 저작력을 얻을 수 있다는 것으로 자연치와 임플란트를 이용한 수복시 공히 적용되는 개념이다. 본 증례는 2급 지적장애로 인해 치료시 협조를 구할 수 없으며 우식으로 인해 다수의 치아가 상실된 환자로 대구치 부위의 심한 골흡수와 상악동의 함기화 및 상악동염으로 인해 제 2 대구치까지의 수복이 용이하지 않아 가급적 위험요인을 줄이면서 최소한의 전신마취로 치료를 종결하기 위해 SDA 개념을 적용, 제 2 소구치까지만 수복이 이루어졌다. 치료 결과 심미적, 기능적으로 만족할 만한 향상이 이루어졌고 추가적인 저작력의 요구는 없었으며 주기적인 재내원으로 구강위생이 강화되었다.