• Asian Pacific Journal of Cancer Prevention
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• v.13 no.7
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• pp.3143-3147
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• 2012

Background: Previous studies investigating the association of physical activity with risk of lung cancer reported conflicting results. In order to update and improve available evidence on any link, a meta-analysis was performed. Method: We searched the PubMed database for prospective cohort studies investigating the relation of physical activity with risk of lung cancer. The pooled relative risk (RR) with its 95% confidence intervals (95%CI) was used to assess the association. Results: We included 14 prospective studies with a total of 1,644,305 participants, with 14,074 incident lung cancer cases documented during follow-up. Meta-analysis of all 14 studies suggested both high and medium levels of physical activity to be associated with decreased risk of lung cancer compared to the reference group with low level of physical activity (for high level, RR = 0.77, 95%CI 0.73-0.81, P < 0.001; for medium level, RR = 0.87, 95%CI 0.83-0.90, P < 0.001). Subgroup analyses by gender found obvious associations in both men and women. No publication bias was observed. Conclusion: Our findings suggest that high and medium levels of physical activity have a beneficial effect on lung cancer by reducing the overall risk of tumour development among both men and women.

• Fisheries and Aquatic Sciences
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• v.21 no.8
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• pp.24.1-24.9
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• 2018

The Korean bottom trawl survey has been deployed on a regular basis for about the last decade as part of groundfish stock assessments. The regularity indicates that they sample groundfish once per grid cell whose sides are half of one latitude and that of one longitude, respectively, and whose inside is furthermore divided into nine nested grids. Unless they have a special reason (e.g., running into a rocky bottom), their sample location is at the center grid of the nine nested grids. Given data collected by the survey, we intended to show how to appropriately estimate not only the survey index of a fish stock but also its uncertainty. For the regularity reason, we applied the systematic sampling theory for the above purposes and compared its results with a reference, which was based on the simple random sampling. When using the survey data about 11 fish stocks, collected by the spring and fall surveys in 2014, the survey indices of those stocks estimated under the systematic sampling were overall more precise than those under the simple random sampling. In estimates of the survey indices in number, the standard errors of those estimates under the systematic sampling were reduced from those under the simple random sampling by 0.23~27.44%, while in estimates of the survey indices in weight, they decreased by 0.04~31.97%. In bias of the estimates, the systematic sampling was the same as the simple random sampling. Our paper is first in formally showing how to apply the systematic sampling theory to the actual data collected by the Korean bottom trawl surveys.

• Fire Science and Engineering
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• v.32 no.4
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• pp.1-6
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• 2018

As a preliminary study to quantify the measurement uncertainty of the Schmidt-Boelter type heat flux gauge, the present study has been conducted to evaluate the measurement error due to the calibration constant supported by manufacturer. Calibrations of heat flux gauges are performed at NIST Fire Research Division using a calibration facility with heat source of a 2000 W halogen-tungsten filament lamp and the calibration constant is obtained by comparing the response of the reference and a standard heat flux gauge at the same irradiance conditions. Calibration for heat flux gauges made by three different manufacturers is compared with their factory calibration constant. Relative error due to fluctuation of output signal from heat flux gauges does not exceed 1% of the mean value and the relative error between calibration of this study and factory calibration constant ranged from 1.5% to 14.3%. The present study shows that a continuous and periodic calibration is necessary for accurate heat flux measurement.

• Atmosphere
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• v.29 no.5
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• pp.585-597
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• 2019

This study evaluates the performance of Weather Research and Forecasting (WRF) model in simulating temperature over the COordinated Regional climate Downscaling EXperiment-East Asia (CORDEX-EA) Phase 2 domain for the reference period (1981~2005), and assesses the changes in temperature and its extremes in the mid-21st century (2026~2050) under global warming based on Representative Concentration Pathway (RCP) scenarios. MPI-ESM-LR forced by two RCP scenarios (RCP2.6 and RCP8.5) is used as initial and lateral boundary conditions. Overall, WRF can capture the observed features of temperature distribution reflecting local topographic characteristic, despite some disagreement between the observed and simulated patterns. Basically, WRF shows a systematic cold bias in daily mean, minimum and maximum temperature over the entire domain. According to the future projections, summer and winter mean temperatures over East Asia will significantly increase in the mid-21st century. The mean temperature rise is expected to be greater in winter than in summer. In accordance with these results, summer (winter) is projected to begin earlier (later) in the future compared to the historical period. Furthermore, a rise in extreme temperatures shows a tendency to be greater in the future. The averages of daily minimum and maximum temperatures above 90 percentiles are likely to be intensified in the high-latitude, while hot days and hot nights tend to be more frequent in the low-latitude in the mid-21st century. Especially, East Asia would be suffered from strong increases in nocturnal temperature under future global warming.

• Journal of the Korean Society of Safety
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• v.27 no.3
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• pp.131-140
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• 2012

Though there might exist not a few differences between cyclic works and atypical works, many researchers have applied the same assessment techniques that used for repetitive works, which may result introduce bias in their conclusions. This research aimed to verify whether there exist non-negligible work characteristics and/or dissimilarity among works with different work nature and whether one of the most prevalent assessment techniques for assessing ergonomic hazards of musculoskeletal disorders, REBA, can be applied to atypical works. For a general hospital, an automobile repair shop, and two auto-part assembly plants which manufactures quite different parts, a questionnaire survey and field investigation and ergonomic assessment were carried out and analyzed statistically with reference to the 3rd Quantification technique. The results showed that there exist remarkable difference between physical factors in cyclic works and atypical non-cyclic works. As for repetitive work, body posture was significant factors affecting on musculoskeletal disorders while atypical works seemed to have none which implied that the necessity of taking psychosocial factors into account for assessment of hazards. Complain rate in repetitive works was highest shoulder, back, and neck or wrist in sequence. However, there existed no consistent trend in complain rate in atypical works. And, though weight of manufacturing objects was a common factor that can partly explain musculoskeletal complain, time duration was significant in atypical work whereas repeatability and body posture were significant in repetitive works. As being the results, to summarize, it could be said that application of conventional ergonomic assessment techniques regardless of repetitiveness would be fruitless, and that the necessity of a unique methodology focused on atypical non-cyclic works should not be neglected.

• Journal of Sensor Science and Technology
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• v.19 no.4
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• pp.306-312
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• 2010

We have detected deoxynivalenol(DON) using a metal-oxide-semiconductor field-effect-transistor(MOSFET)-based biosensor. The MOSFET-based biosensor is fabricated by a standard complementary metal-oxide-semiconductor(CMOS) process, and the biosensor's electrical characteristics were investigated. The output of the sensor was stabilized by employing a reference electrode that applies a fixed bias to the gate. Au which has a chemical affinity for thiol was used as the gate metal to immobilize a self-assembled monolayer(SAM) made of 16-mercaptohexadecanoic acid(MHDA). The SAM was used to immobilize anti-deoxynivalenol antibody. The carboxyl group of the SAM was bound to the anti- deoxynivalenol antibody. Anti-deoxynivalenol antibody and deoxynivalenol were bound by an antigen-antibody reaction. In this study, it is confirmed that the MOSFET-based biosensor can detect deoxynivalenol at concentrations as low as 0.1 ${\mu}g$/ml. The measurements were performed in phosphate buffered saline(PBS; pH 7.4) solution. To verify the interaction among the SAM, antibody, and antigen, surface plasmon resonance(SPR) measurements were performed.

• The Korean Journal of Pain
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• v.33 no.1
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• pp.3-12
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• 2020

Neuropathic pain after spinal cord injury (SCI) has a significant negative impact on the patients' quality of life. The objective of this systematic review is to examine the safety and efficacy of pregabalin (PGB) and gabapentin (GBP) in the treatment of neuropathic pain due to SCI. PubMed, the Cochrane Library, Embase, Scopus, and the Web of Science were searched up to December 2018. The reference lists of key and review studies were reviewed for additional citations. The quality of the studies was evaluated using the Cochrane Collaboration's tools for assessing the risk of bias. A meta-analysis was performed for primary and secondary outcomes. Eight studies were eligible for inclusion. Meta-analysis of PGB vs. placebo showed that PGB was effective for neuropathic pain (standardized mean difference [SMD] = -0.40; 95% confidence interval [CI]: -0.78, -0.01), anxiety (MD = -0.68; 95% CI: -0.77, -0.59), depression (mean difference [MD] = -0.99; 95% CI: -1.08, -0.89), and sleep interference (MD = -1.08; 95% CI: -1.13, -1.02). Also, GBP was more effective than a placebo for reducing pain. No significant difference was observed between the efficacy of the two drugs (MD = -0.37; 95% CI: -1.67, 0.93). There was no significant difference between the two drugs for discontinuation due to adverse events (risk ratio = 3.00; 95% CI: 0.81, 11.15). PGB and GBP were effective vs. placebos in decreasing neuropathic pain after SCI. Also, there was no significant difference between the two drugs for decreasing pain and adverse events.

• Nutrition Research and Practice
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• v.15 no.1
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• pp.95-105
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• 2021

BACKGROUND/OBJECTIVES: The measurement of body composition, including muscle and fat mass, remains challenging in large epidemiological studies due to time constraint and cost when using accurate modalities. Therefore, this study aimed to develop and validate prediction equations according to sex to measure lean body mass (LBM), appendicular skeletal muscle mass (ASM), and body fat mass (BFM) using anthropometric measurement, serum creatinine level, and lifestyle factors as independent variables and dual-energy X-ray absorptiometry as the reference method. SUBJECTS/METHODS: A sample of the Korean general adult population (men: 7,599; women: 10,009) from the Korean National Health and Nutrition Examination Survey 2008-2011 was included in this study. The participants were divided into the derivation and validation groups via a random number generator (with a ratio of 70:30). The prediction equations were developed using a series of multivariable linear regressions and validated using the Bland-Altman plot and intraclass correlation coefficient (ICC). RESULTS: The initial and practical equations that included age, height, weight, and waist circumference had a different predictive ability for LBM (men: R2 = 0.85, standard error of estimate [SEE] = 2.7 kg; women: R2 = 0.78, SEE = 2.2 kg), ASM (men: R2 = 0.81, SEE = 1.6 kg; women: R2 = 0.71, SEE = 1.2 kg), and BFM (men: R2 = 0.74, SEE = 2.7 kg; women: R2 = 0.83, SEE = 2.2 kg) according to sex. Compared with the first prediction equation, the addition of other factors, including serum creatinine level, physical activity, smoking status, and alcohol use, resulted in an R2 that is higher by 0.01 and SEE that is lower by 0.1. CONCLUSIONS: All equations had low bias, moderate agreement based on the Bland-Altman plot, and high ICC, and this result showed that these equations can be further applied to other epidemiologic studies.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.2
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• pp.17-32
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• 2022

This study explored an approach to estimate a flow-density diagram(FD) on a link in highway traffic environment by utilizing probe vehicles' time headway records. To study empirical flow-density diagram(EFD), the probe vehicles with vision sensors were recruited for collecting driving records for nine months and the vision sensor data pre-processing and GIS-based map matching were implemented. Then, we examined the new EFDs to evaluate validity with reference diagrams which is derived from loop detection traffic data. The probability distributions of time headway and distance headway as well as standard deviation of flow and density were utilized in examination. As a result, it turned out that the main factors for estimation errors are the limited number of probe vehicles and bias of flow status. We finally suggest a method to improve the accuracy of EFD model.

• Journal of Periodontal and Implant Science
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• v.54 no.1
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• pp.3-12
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• 2024

Deep learning (DL) offers promising performance in computer vision tasks and is highly suitable for dental image recognition and analysis. We evaluated the accuracy of DL algorithms in identifying and classifying dental implant systems (DISs) using dental imaging. In this systematic review and meta-analysis, we explored the MEDLINE/PubMed, Scopus, Embase, and Google Scholar databases and identified studies published between January 2011 and March 2022. Studies conducted on DL approaches for DIS identification or classification were included, and the accuracy of the DL models was evaluated using panoramic and periapical radiographic images. The quality of the selected studies was assessed using QUADAS-2. This review was registered with PROSPERO (CRDCRD42022309624). From 1,293 identified records, 9 studies were included in this systematic review and meta-analysis. The DL-based implant classification accuracy was no less than 70.75% (95% confidence interval [CI], 65.6%-75.9%) and no higher than 98.19 (95% CI, 97.8%-98.5%). The weighted accuracy was calculated, and the pooled sample size was 46,645, with an overall accuracy of 92.16% (95% CI, 90.8%-93.5%). The risk of bias and applicability concerns were judged as high for most studies, mainly regarding data selection and reference standards. DL models showed high accuracy in identifying and classifying DISs using panoramic and periapical radiographic images. Therefore, DL models are promising prospects for use as decision aids and decision-making tools; however, there are limitations with respect to their application in actual clinical practice.