• Title/Summary/Keyword: Risk Estimation

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Algorithms for Causality Evaluation of Adverse Events from Health/Functional Foods (건강기능식품 부작용 원인분석을 위한 알고리즘)

  • Lee, Kyung-Jin;Park, Kyoung-Sik;Kim, Jeong-Hun;Lee, Young-Joo;Yoon, Tae-Hyung;No, Ki-Mi;Park, Mi-Sun;Leem, Dong-Gil;Yoon, Chang-Yong;Jeong, Ja-Young
    • Journal of Food Hygiene and Safety
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    • v.26 no.4
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    • pp.302-307
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    • 2011
  • One of the most important objectives of post-marketing monitoring of dietary supplements is the early detection of unknown and unexpected adverse events (AEs). Several causality algorithms, such as the Naranjo scale, the RUCAM scale, and the M & V scale are available for the estimation of the likelihood of causation between a product and an AE. Based on the existing algorithms, the Korea Food & Drug Administration has developed a new algorithm tool to reflect the characteristics of dietary supplements in the causality analysis. However, additional work will be required to confirm if the newly developed algorithm tool has reasonable sensitivity and not to generate an unacceptable number of false positives signals.

A Study on Pillar Behavior of Twin Parallel Tunnels by Numerical Approach (병렬터널 필라부 거동에 대한 수치해석 검토)

  • Byun, Yoseph;Kim, Hyungi;Lee, Sangsu;Chun, Byungsik
    • Journal of the Korean GEO-environmental Society
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    • v.11 no.8
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    • pp.49-55
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    • 2010
  • Safety estimation of the pillar between parallel tunnels are very important considering stress concentration in case the piller width is not enough to secure the stability. Pillar width needs to be determined properly because of the progressive failure-risk of pillar due to stress-concentration. In this research, the effect of element size in numerical analysis was evaluated based on that yield pillar's stability and proposed systematic analysis about pilar's stability examination. In consequence of it, element size does not give any effect on intensity stress ratio. On the other hand, the analysis using the smaller element size results in lower safety factor in strength reduction technique. In case of the weathered re.k on the main ground layer, the analysis of result was not reliable. In conclusion, the smaller element size is, the more stable factor is.

Characteristics and Prediction of Lung Cancer Mortality in China from 1991 to 2013

  • Fang, Jia-Ying;Dong, Hong-Li;Wu, Ku-Sheng;Du, Pei-Ling;Xu, Zhen-Xi;Lin, Kun
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.5829-5834
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    • 2015
  • Objective: To describe and analyze the epidemiological characteristics of lung cancer mortality in China from 1991 to 2013, forecast the future five-year trend and provide scientific evidence for prevention and management of lung cancer. Materials and Methods: Mortality data for lung cancer in China from 1991 to 2013 were used to describe epidemiological characteristics. Trend surface analysis was applied to analyze the geographical distribution of lung cancer. Four models, curve estimation, time series modeling, gray modeling (GM) and joinpoint regression, were performed to forecast the trend for the future. Results: Since 1991 the mortality rate of lung cancer increased yearly. The rate for males was higher than that for females and rates in urban areas were higher than in rural areas. In addition, our results showed that the trend will continue to increase in the ensuing 5 years. The mortality rate increased from age 45-50 and peaked in the group of 85 years old. Geographical analysis indicated that people living in northeast China provinces and the coastal provinces in eastern China had a higher mortality rate for lung cancer than those living in the centre or western Chinese provinces. Conclusions: The standardized mortality rate of lung cancer has constantly increased from 1991 to 2013, and been predicted to continue in the ensuing 5 years. Further efforts should be concentrated on education of the general public to increase prevention and early detection. Much better prevention and management is needed in high mortality areas (northeastern and eastern parts of China) and high risk populations (45-50-year-olds).

Lack of Association of the MDR1 C3435T Polymorphism with Susceptibility to Gastric Cancer and Peptic Ulcer: a Systemic Review and Meta-analysis

  • Wu, Dan-Dan;Zhang, Ji-Xiang;Li, Jiao;Dong, Wei-Guo
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.7
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    • pp.3021-3027
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    • 2014
  • Background: The multidrug resistance 1 gene (MDR1) C3435T polymorphism has been demonstrated to influence the P-glycoprotein (P-gp) activity level which is related to inflammation and carcinogenesis. This meta-analysis was performed to estimate the association between the MDR1 C3435T polymorphism and the risk of gastric cancer (GC) and peptic ulcer (PU). Materials and Methods: A literature search was conducted with PubMed, Embase and the Cochrane library up to November 2013. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of association. Data were analyzed using Review Manager (Version 5.2), and Stata package (version 12.0) for estimation of publication bias. Results: Six case-control studies were included, of which five were for GC and two for PU. Overall, no evidence was found for any association between the MDR1 C3435T polymorphism and the susceptibility to GC and PU. In the stratified analysis by H. pylori infection status, stage and histology classification of GC, and PU type, there was still no significant association between them. Conclusions: This meta-analysis suggested that the MDR1 C3435T polymorphism is not associated with susceptibility to GC and PU. Large and well-designed studies are warranted to validate our findings.

Evaluation of Computer-Assisted Quantitative Volumetric Analysis for Pre-Operative Resectability Assessment of Huge Hepatocellular Carcinoma

  • Tang, Jian-Hua;Yan, Fu-Hua;Zhou, Mei-Ling;Xu, Peng-Ju;Zhou, Jian;Fan, Jia
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.5
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    • pp.3045-3050
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    • 2013
  • Purpose: Hepatic resection is arguably the preferred treatment for huge hepatocellular carcinoma (H-HCC). Estimating the remnant liver volume is therefore essential. This study aimed to evaluate the feasibility of using computer-assisted volumetric analysis for this purpose. Methods: The study involved 40 patients with H-HCC. Laboratory examinations were conducted, and a contrast CT-scan revealed that 30 cases out of the participating 40 had single-lesion tumors. The remaining 10 had less than three satellite tumors. With the consensus of the team, two physicians conducted computer-assisted 3D segmentation of the liver, tumor, and vessels in each case. Volume was automatically computed from each segmented/labeled anatomical field. To estimate the resection volume, virtual lobectomy was applied to the main tumor. A margin greater than 1 cm was applied to the satellite tumors. Resectability was predicted by computing a ratio of functional liver resection (R) as (Vresected-Vtumor)/(Vtotal-Vtumor) x 100%, applying a threshold of 50% and 60% for cirrhotic and non-cirrhotic cases, respectively. This estimation was then compared with surgical findings. Results: Out of the 22 patients who had undergone hepatectomies, only one had an R that exceeded the threshold. Among the remaining 18 patients with non-resectable H-HCC, 12 had Rs that exceeded the specified ratio and the remaining 6 had Rs that were < 50%. Four of the patients who had Rs less than 50% underwent incomplete surgery due to operative findings of more extensive satellite tumors, vascular invasion, or metastasis. The other two cases did not undergo surgery because of the high risk involved in removing the tumor. Overall, the ratio of functional liver resection for estimating resectability correlated well with the other surgical findings. Conclusion: Efficient pre-operative resectability assessment of H-HCC using computer-assisted volumetric analysis is feasible.

Financial Disclosure and the Cost of Equity Capital: The Empirical Test of the Largest Listed Companies of Kazakhstan

  • Baimukhamedova, Aizhan;Baimukhamedova, Gulzada;Luchaninova, Albina
    • The Journal of Asian Finance, Economics and Business
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    • v.4 no.3
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    • pp.5-17
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    • 2017
  • This study extends research into whether disclosure of corporate and financial information is associated with firms' costs of equity capital. This study sets out to examine empirically the determinants of corporate disclosure in the annual reports of 37 largest and most liquid firms listed on Kazakhstan Stock Exchange (KASE) in Kazakhstan. It also reports the results of the association between company-specific characteristics and disclosure of the sample companies. Based on the analysis of existing empirical research, the disclosure index has been constructed and regression analysis of the influence of the disclosure index on the cost of equity capital has been conducted. The obtained results show that the received findings correlate with foreign empirical studies, and the disclosure index in this sample has a negative impact on the cost of equity capital. Using cost of equity capital estimates derived from capital asset pricing model, we find that firms with higher levels of financial transparency are associated with significantly lower costs of equity capital. Economic theory assumes that by increasing the level of corporate reporting, firms not only increase their stock market liquidity, but also decrease the investors' estimation risk, arising from uncertainty about future returns and payout distributions. The results show that firms on the Kazakhstan market can reduce their cost of equity capital by increasing the level of their voluntary corporate disclosures.

Study on the Correlation between Nicotine Concentrations in Environmental Tobacco Smoke and Urinary Cotinine Concentrations of Nonsmokers (비흡연자의 Nicotine에 대한 노출량과 뇨중 Cotinine 농도의 상관성에 관한 연구)

  • Roh, Jin-Ho;Shin, Dong-Chun;Kim, Jong-Man;Chung, Yong
    • Environmental Analysis Health and Toxicology
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    • v.5 no.3_4
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    • pp.47-56
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    • 1990
  • Smoking damages nonsmoker's health who have been exposed to passive smoking as well as smoker's own health. Passive smoking can cause serious health damage to particular groups, such as the old aged, children and pregnant women. The purpose of this study is to investigate the relationship between nicotine concentrations in environmental tobacco smoke (ETS) and urinary cotinine concentrations of nonsmokers exposed to ETS, and to provide basic information related to health risk assessment. The results of this study were summarized as follows: 1. When 180 cigarrette were smoked during S hours (high concentrations exposure) in 132 m$^3$chamber, mean concentrations of nicotine in ETS showed 263.52 $\mu\textrm{g}$/m$^3$${\pm}$51.93. When 45 cigarretts were smoked (low concentrations exposure), it was 69.43${\pm}$8.96 $\mu\textrm{g}$/m$^3$. 2. The urinary cotinine concentrations of each times (0, 2.5, 5, 17 and 24 hours) in nonsmokers ranged from 0.27∼12.52 ng/ml in high concentrations exposure and 0.22∼2.28 ng/ml in low concentrations exposure. Mean while the total urinary cotinine concentrations during 24 hours ranged from 11.62∼31.65 ng/ml in high concentrations exposure and 3.45∼5.64 ng/ml in low concentrations exposure. 3. The correlation equation and coefficient between cotinine concentrations in nonsmokers' urine (y) and nicotine concentrations in ETS (x) was y=0.421+0.0171x and 0:875 (p<0.01) respectively, 4. The quantity of nonsmokers' smoking exposure by passive smoking can be assumed as based on the estimation of nicotine concentrations in ETS by measuring cotinine concentrations of nonsmokers' urine.

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A Status Report on Dual Energy X-ray Absorptiometry Quality Control in Korea (이중에너지 방사선흡수 골밀도 장치의 품질관리 현황)

  • Kim, Jung-Su;Rho, Young-Hoon;Lee, In-Ju;Kim, Sung-Su;Kim, Kyoung-Ah;Kim, Jung-Min
    • Journal of radiological science and technology
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    • v.39 no.4
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    • pp.527-534
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    • 2016
  • Dual-energy X-ray absorptiometry (DEXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. In 2016, DEXA devices operating is 5617 in Korea. In this study we investigated the quality of management practices survey for DEXA equipment and we analyzed it. We got a survey response rate of 12.6%. Accurate bone densitometry test is used data for estimation a patient's risk of fracture. However, improper bone densitometry will increase the possibility of causing a false positive. Therefore. it is essential to use the proper aids accurate bone densitomenty to be performed, and the quality control of the device to reduce the error factor of the tester through the training to reduce error for the device and the attitude.

Uncertainty Analysis on the Simulations of Runoff and Sediment Using SWAT-CUP (SWAT-CUP을 이용한 유출 및 유사모의 불확실성 분석)

  • Kim, Minho;Heo, Tae-Young;Chung, Sewoong
    • Journal of Korean Society on Water Environment
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    • v.29 no.5
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    • pp.681-690
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    • 2013
  • Watershed models have been increasingly used to support an integrated management of land and water, non-point source pollutants, and implement total daily maximum load policy. However, these models demand a great amount of input data, process parameters, a proper calibration, and sometimes result in significant uncertainty in the simulation results. For this reason, uncertainty analysis is necessary to minimize the risk in the use of the models for an important decision making. The objectives of this study were to evaluate three different uncertainty analysis algorithms (SUFI-2: Sequential Uncertainty Fitting-Ver.2, GLUE: Generalized Likelihood Uncertainty Estimation, ParaSol: Parameter Solution) that used to analyze the sensitivity of the SWAT(Soil and Water Assessment Tool) parameters and auto-calibration in a watershed, evaluate the uncertainties on the simulations of runoff and sediment load, and suggest alternatives to reduce the uncertainty. The results confirmed that the parameters which are most sensitive to runoff and sediment simulations were consistent in three algorithms although the order of importance is slightly different. In addition, there was no significant difference in the performance of auto-calibration results for runoff simulations. On the other hand, sediment calibration results showed less modeling efficiency compared to runoff simulations, which is probably due to the lack of measurement data. It is obvious that the parameter uncertainty in the sediment simulation is much grater than that in the runoff simulation. To decrease the uncertainty of SWAT simulations, it is recommended to estimate feasible ranges of model parameters, and obtain sufficient and reliable measurement data for the study site.

Development and Use of Digital Climate Models in Northern Gyunggi Province - I. Derivation of DCMs from Historical Climate Data and Local Land Surface Features (경기북부지역 정밀 수치기후도 제작 및 활용 - I. 수치기후도 제작)

  • 김성기;박중수;이은섭;장정희;정유란;윤진일
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.6 no.1
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    • pp.49-60
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    • 2004
  • Northern Gyeonggi Province(NGP), consisting of 3 counties, is the northernmost region in South Korea adjacent to the de-militarized zone with North Korea. To supplement insufficient spatial coverage of official climate data and climate atlases based on those data, high-resolution digital climate models(DCM) were prepared to support weather- related activities of residents in NGP Monthly climate data from 51 synoptic stations across both North and South Korea were collected for 1981-2000. A digital elevation model(DEM) for this region with 30m cell spacing was used with the climate data for spatially interpolating daily maximum and minimum temperatures, solar irradiance, and precipitation based on relevant topoclimatological models. For daily minimum temperature, a spatial interpolation scheme accommodating the potential influences of cold air accumulation and the temperature inversion was used. For daily maximum temperature estimation, a spatial interpolation model loaded with the overheating index was used. Daily solar irradiances over sloping surfaces were estimated from nearby synoptic station data weighted by potential relative radiation, which is the hourly sum of relative solar intensity. Precipitation was assumed to increase with the difference between virtual terrain elevation and the DEM multiplied by an observed rate. Validations were carried out by installing an observation network specifically for making comparisons with the spatially estimated temperature pattern. Freezing risk in January was estimated for major fruit tree species based on the DCMs under the recurrence intervals of 10, 30, and 100 years, respectively. Frost risks at bud-burst and blossom of tree flowers were also estimated for the same resolution as the DCMs.