• 제목/요약/키워드: likelihood ratio index

검색결과 44건 처리시간 0.02초

Selection and optimization of nutritional risk screening tools for esophageal cancer patients in China

  • Dong, Wen;Liu, Xiguang;Zhu, Shunfang;Lu, Di;Cai, Kaican;Cai, Ruijun;Li, Qing;Zeng, Jingjing;Li, Mei
    • Nutrition Research and Practice
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    • 제14권1호
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    • pp.20-24
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    • 2020
  • BACKGROUND/OBJECTIVES: Malnutrition has multiple impacts on surgical success, postoperative complications, duration of hospital stay, and costs, particularly for cancer patients. There are various nutrition risk screening tools available for clinical use. Herein, we aim to determine the most appropriate nutritional risk screening system for esophageal cancer (EC) patients in China. SUBJECTS/METHODS: In total, 138 EC patients were enrolled in this study and evaluated by experienced nurses using three different nutritional screening tools, the Nutrition Risk Screening 2002 tool (NRS2002), the Patient-generated Subjective Globe Assessment (PG-SGA), and the Nutrition Risk Index (NRI).We compared sensitivity, specificity, positive and negative likelihood ratios, and Youden index generated by each of the three screening tools. Finally, cut-off points for all three tools were re-defined to optimize and validate the best nutritional risk screening tool for assessing EC patients. RESULTS: Our data suggested that all three screening tools were 100% sensitive for EC patients, while the specificities were 44.4%, 2.96%, and 59.26% for NRS 2002, PG-SGA, and NRI, respectively. NRI had a higher positive likelihood ratio as well as a higher area under the receiver operating characteristic curve compared to those of NRS 2002 and PG-SGA; although, all three tools had null negative likelihood ratios. After adjusting the cut-off points, the specificity and accuracy for all tools were significantly improved, however, the NRI remained the most appropriate nutritional risk screening system for EC patients. CONCLUSIONS: The NRI is the most suitable (highest sensitivity and accuracy) nutritional risk screening tool for EC patients. The performance of the NRI can be significantly improved if the cut-off point is modified according to the results obtained using MedCalc software.

The relationship between skeletal muscle mass and the KOSHA cardiovascular risk in obese male workers

  • Hyo Won Chong;JunSeok Son;Changho Chae;Changho Jae
    • Annals of Occupational and Environmental Medicine
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    • 제35권
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    • pp.40.1-40.10
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    • 2023
  • Background: Efforts for the prevention and management of cardiovascular diseases (CVDs) in workers have been actively pursued. Obesity is one of the important risk factors related to CVDs. Obesity has various metabolic characteristics, and some individuals can be metabolically healthy. Body composition including skeletal muscle mass is known to have protective effect in obesity. The study aims to investigate the association between skeletal muscle mass and Korea Occupational Safety and Health Agency (KOSHA) CVD risk among obese male manufacturing workers in Korea and to identify appropriate indicators of skeletal muscle mass for predicting risk of CVDs. Methods: The study was conducted on 2,007 obese male workers at a manufacturing industry aged more than 19 years. Skeletal muscle mass, skeletal muscle index (SMI), skeletal muscle mass percent (SMM%) and skeletal muscle to body fat ratio (MFR) were used to evaluate body composition and these indicators were divided into quartiles. The odds ratios (ORs) and 95% confidence intervals (CIs) for the KOSHA CVD risk groups according to quartiles of skeletal muscle mass indicators were estimated using ordinal logistic regression analysis. Results: The OR for the KOSHA CVD risk groups in the highest quartile of SMI was 1.67 (95% CI: 1.42-1.92), while the ORs for the KOSHA CVD risk groups in the highest quartiles of SMM%, SMM/body mass index (BMI), and MFR were 0.47 (95% CI: 0.22-0.72), 0.51 (95% CI: 0.05-0.76), and 0.48 (95% CI: 0.23-0.74), respectively. Conclusions: We found that high SMI increase the likelihood of high risk of CVDs, while high SMM%, SMM/BMI, and MFR lower the likelihood of high risk of CVDs. Accurate evaluation of skeletal muscle mass can help assess the cardiovascular risk in obese male workers.

수문 및 기후 자료에 대한 선형 경향성 및 평균이동 분석 (Trend and Shift Analysis for Hydrologic and Climate Series)

  • 오제승;김형수;서병하
    • 대한토목학회논문집
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    • 제26권4B호
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    • pp.355-362
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    • 2006
  • 본 연구에서는 수문 및 기후 시계열 자료에 존재하는 경향성을 분석하기 위하여 MK 검정, Spearman's Rho 검정, Linear Regression 검정, 비모수 Cusum 검정, Cumulative Deviation 검정, Worsley Likelihood Ratio 검정, Rank Sum 검정, Student's t 검정 등의 8가지 기법을 사용하였다. 관측된 연 강우량과 유입량 시계열 자료, 나이테 자료 그리고 SOI 자료에 적용하여 그 결과를 비교 분석 하였다. 분석 결과 시계열 자료에는 어떤 기울기를 가지거나 어느 시점을 기준으로 평균이 변화하는 두 가지의 경향성이 존재함을 확인 할 수 있었다. 경향성을 나타낸 8개의 강우자료중 4개 지점이 평균이동(shift)을 나타내었으며, 18개 지역의 나이테 지수중 8개 지역과 월별 SOI자료 중 3, 4월자료에서 경향성의 존재가 확인되었고, 소양강댐 유입량 자료에서는 경향성이 나타나지 않았다. 특히, 나이테 지수의 경우에는 평균이동으로 인한 경향성만을 가지고 있는 자료가 확인되었다. 또한 정상성 검정을 위한 ADF 검정과 비선형성 검정을 위한 BDS 통계검정 기법을 적용하였다. 본 연구를 통하여 여러 경향성 분석 기법을 비교할 수 있었으며, 실제 관측된 수문 및 기후 시계열에 존재하는 경향성을 확인 할 수 있었고, 연구 결과를 통하여 수문시계열 해석시 다양한 분석을 통한 경향성의 존재여부를 확인 하여야 한다는 것을 알 수 있었다.

공간예측모형에 기반한 산사태 취약성 지도 작성과 품질 평가 (Mapping Landslide Susceptibility Based on Spatial Prediction Modeling Approach and Quality Assessment)

  • 알-마문;박현수;장동호
    • 한국지형학회지
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    • 제26권3호
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    • pp.53-67
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    • 2019
  • The purpose of this study is to identify the quality of landslide susceptibility in a landslide-prone area (Jinbu-myeon, Gangwon-do, South Korea) by spatial prediction modeling approach and compare the results obtained. For this goal, a landslide inventory map was prepared mainly based on past historical information and aerial photographs analysis (Daum Map, 2008), as well as some field observation. Altogether, 550 landslides were counted at the whole study area. Among them, 182 landslides are debris flow and each group of landslides was constructed in the inventory map separately. Then, the landslide inventory was randomly selected through Excel; 50% landslide was used for model analysis and the remaining 50% was used for validation purpose. Total 12 contributing factors, such as slope, aspect, curvature, topographic wetness index (TWI), elevation, forest type, forest timber diameter, forest crown density, geology, landuse, soil depth, and soil drainage were used in the analysis. Moreover, to find out the co-relation between landslide causative factors and incidents landslide, pixels were divided into several classes and frequency ratio for individual class was extracted. Eventually, six landslide susceptibility maps were constructed using the Bayesian Predictive Discriminant (BPD), Empirical Likelihood Ratio (ELR), and Linear Regression Method (LRM) models based on different category dada. Finally, in the cross validation process, landslide susceptibility map was plotted with a receiver operating characteristic (ROC) curve and calculated the area under the curve (AUC) and tried to extract success rate curve. The result showed that Bayesian, likelihood and linear models were of 85.52%, 85.23%, and 83.49% accuracy respectively for total data. Subsequently, in the category of debris flow landslide, results are little better compare with total data and its contained 86.33%, 85.53% and 84.17% accuracy. It means all three models were reasonable methods for landslide susceptibility analysis. The models have proved to produce reliable predictions for regional spatial planning or land-use planning.

The GARCH-GPD in market risks modeling: An empirical exposition on KOSPI

  • Atsmegiorgis, Cheru;Kim, Jongtae;Yoon, Sanghoo
    • Journal of the Korean Data and Information Science Society
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    • 제27권6호
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    • pp.1661-1671
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    • 2016
  • Risk analysis is a systematic study of uncertainties and risks we encounter in business, engineering, public policy, and many other areas. Value at Risk (VaR) is one of the most widely used risk measurements in risk management. In this paper, the Korean Composite Stock Price Index data has been utilized to model the VaR employing the classical ARMA (1,1)-GARCH (1,1) models with normal, t, generalized hyperbolic, and generalized pareto distributed errors. The aim of this paper is to compare the performance of each model in estimating the VaR. The performance of models were compared in terms of the number of VaR violations and Kupiec exceedance test. The GARCH-GPD likelihood ratio unconditional test statistic has been found to have the smallest value among the models.

최강력 검정을 위한 퍼지 포아송 가설의 검정 (Fuzzy Hypothesis Test by Poisson Test for Most Powerful Test)

  • 강만기;서현아
    • 한국지능시스템학회논문지
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    • 제19권6호
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    • pp.809-813
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    • 2009
  • We want to show that the construct of best fuzzy tests for certain fuzzy situations of Poisson distribution. Due to Neyman and Pearson theorem, if we have ${\theta}_0$ and ${\theta}_1$ be distinct fuzzy values of ${\Omega}=\{{\theta}\;:\;{\theta}\;=\;{\theta}_0,\;{\theta}_1\}$ such that $L({\theta}_0\;:\;X)/L({\theta}_1\;:\;X)$ < k, then k is a fuzzy number. For each fuzzy random samples point $X\;{\subset}\;C$, we have most power test for fuzzy critical region C by agreement index.

Does a High Ratio of Dietary Omega-6/Omega-3 Fatty Acids Increase the Risk of Helicobacter pylori Infection? A Case-Control Study

  • Masoumeh Khalighi Sikaroudi;Zohreh Ebrahimi;Melika Darzi;Zainab Shateri;Mehran Nouri;Mohsen Masoodi;Mahdi Hejazi;Farzad Shidfar
    • Clinical Nutrition Research
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    • 제13권3호
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    • pp.176-185
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    • 2024
  • Helicobacter pylori infection is the cause of 90% of non-cardia gastric cancer. Several dietary elements have been identified as possible contributors to H. pylori infection and its advancement through various pathways. Based on the anti-inflammatory and anti-microbial effects of a diet low in omega-6 and high in omega-3 polyunsaturated fatty acids (PUFAs), this study aimed to assess the ratio of dietary omega-6 to omega-3 PUFAs and the risk of developing H. pylori. The present case-control study was conducted on 150 cases with H. pylori infection and 302 controls. The omega-6 to omega-3 ratio was calculated using food intake information sourced from a validated food frequency questionnaire. Physical activity and demographic data were collected through a related questionnaire. The association between the odds of H. pylori infection and the omega-6 to omega-3 ratio was evaluated using logistic regression models. A p value < 0.05 was considered statistically significant. The findings revealed that individuals in the third tertile had significantly higher odds of H. pylori (odds ratio [OR], 2.10; 95% confidence interval [CI], 1.30-3.40) in the crude model. Furthermore, even after adjusting the potential confounders including sex, age, body mass index, physical activity, energy intake, alcohol, and smoking status, this association remained significant (fully adjusted model: OR, 2.00; 95% CI, 1.17-3.34). Our study revealed a higher ratio of omega-6 to omega-3 was related to a higher likelihood of H. pylori infection. Therefore, it is advisable to maintain a balanced intake of PUFAs in the diet.

여자 노인의 거주지별 영양상태 및 관련 요인 (Nutrition States and Related Factors of Female Elderly according to Residence)

  • 박미연;박정영;박필숙
    • 동아시아식생활학회지
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    • 제25권1호
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    • pp.39-48
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    • 2015
  • This study aimed to compare and evaluate nutritive conditions of the female elderly (2,893 people) based on a national health nutrition survey and health-related factors influencing nutritional intake. The results are as follows.- Average age of all subjects was $72.12{\pm}5.2$ old. BMI ($24.48{\pm}3.3kg/m^2$) and waist size ($83.9{\pm}9.5cm$) of urban elderly was larger ($23.74{\pm}3.3kg/m^2$, $82.28{\pm}9.9cm$) than that of rural elderly. MAR[4] and MAR[10] were also higher in urban elderly than rural elderly. The results of multiple regression analysis showed that factors influencing poor nutrition of elderly subjects were increasing age, smoking, and self-rated health. Old-old and current smokers were associated with a higher likelihood of poor nutrition (OR 1.82, 95%CI 1.43~2.30) and (OR 3.40, 95%CI 2.17~5.33) elderly female subjects in urban areas. Smoking (OR 2.29, 95%CI 1.33~3.95), poor self-rated health (OR 1.55, 95%CI 1.11~2.16), over nine hours of sleep per nighting (OR 1.72, 95%CI 1.17~2.53) and stress (OR 1.46, 95%CI 1.10~1.92) of elderly female subjects in rural areas were associated with higher likelihood of a poor nutrition. In conclusion, rural elderly are more influenced by poor health practice behaviors (self-rated health, sleeping stress) and psychological factors. Nutrition status of the rural elderly is worse than that of the urban elderly. To reduce nutritional risk of Korean elderly, especially rural elderly, active nutrition arbitration should include psychological environmental factors.

최적의 Bluetooth GFSK 신호 수신을 위한 Viterbi 기반 저복잡도 FSM 설계 (Design of Low-Complexity FSM based on Viterbi for Optimum Bluetooth GFSK Signal Receiver)

  • 권택원;이규만
    • 디지털융복합연구
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    • 제20권1호
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    • pp.185-190
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    • 2022
  • Bluetooth는 다양한 소비자 전자 장치 간의 연결 매체로 널리 사용되는 공통 무선 기술이다. Bluetooth 수신기는 주로 신호 대 잡음비 성능 개선을 위해 일반적으로 Viterbi 알고리즘을 채택하지만 전송단에서의 irrational modulation index(무리수 변조 지수)로 수신단의 지속적인 탐색 및 추정이 필요하며 이를 위한 복잡한 하드웨어와 계산을 요구한다. 본 논문에서는 이러한 복잡도 문제를 해결하기 위해 비동기 최대 우도 추정(MLE, Maximum-likelihood Estimation) 기반 8-state Viterbi FSM을 제안한다. 본 논문에서 제안한 최적의 Viterbi FSM은 전송단에서의 변조 지수에 대한 사전 정보 및 추정이 필요 없으며 GFSK(Gaussian Frequency Shift Keying) 심볼 검출이 가능하다. 제안한 알고리즘에 대한 성능은 HV1/HV2 패킷을 사용하여 평가하였으며, 시뮬레이션 결과는 DD(Decision Direct)와 같은 이상적인 접근 방식과 비교하여 10-3 BER에서 약 2dB 성능 향상을 보여주었다.

Impact of obesity on the severity of trauma in patients injured in pedestrian traffic accidents

  • Pillsung, Oh;Jin-Seong, Cho;Jae Ho, Jang;Jae Yeon, Choi;Woo Sung, Choi;Byungchul, Yu
    • Journal of Trauma and Injury
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    • 제35권4호
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    • pp.240-247
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    • 2022
  • Purpose: Studies on the relationship between obesity and injuries, especially those sustained in pedestrian traffic accidents, are lacking. We aimed to assess the effects of obesity on the severity of injury at the time of admission to the emergency room in patients who experienced pedestrian traffic accidents. Methods: This study included trauma patients registered in the Korean Trauma Database from July 1, 2018 to December 31, 2020, whose mechanism of injury was pedestrian traffic accidents and who were treated at a single institution. Those aged below 15 years were excluded. Patients were assigned to nonobese and obese groups based on a body mass index of 25 kg/m2. An Injury Severity Score of 25 or greater was considered to indicate a critical injury. Results: In total, 679 cases of pedestrian traffic accidents were registered during the study period, and 543 patients were included in the final analysis. Of them, 360 patients (66.3%) and 183 patients (33.7%) were categorized as nonobese and obese, respectively. The median age was significantly higher in the nonobese group than in the obese group (60 vs. 58 years). Multivariate analysis demonstrated that the odds ratio for critical injury in obese patients was 1.59 (95% confidence interval, 1.01-2.48) compared with nonobese patients. Conclusions: Obesity affected the likelihood of sustaining severe injuries in pedestrian traffic accidents. Future studies should analyze the effects of body mass index on the pattern and severity of injuries in patients with more diverse injury mechanisms using large-scale data.