• Korean Journal of Remote Sensing
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• v.34 no.1
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• pp.45-74
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• 2018

Landslide is a natural hazard that threats lives and properties in many areas around the world. Landslides are difficult to recognize, particularly in rainforest regions. Thus, an accurate, detailed, and updated inventory map is required for landslide susceptibility, hazard, and risk analyses. The inconsistency in the results obtained using different features selection techniques in the literature has highlighted the importance of evaluating these techniques. Thus, in this study, six techniques of features selection were evaluated. Very-high-resolution LiDAR point clouds and orthophotos were acquired simultaneously in a rainforest area of Cameron Highlands, Malaysia by airborne laser scanning (LiDAR). A fuzzy-based segmentation parameter (FbSP optimizer) was used to optimize the segmentation parameters. Training samples were evaluated using a stratified random sampling method and set to 70% training samples. Two machine-learning algorithms, namely, Support Vector Machine (SVM) and Random Forest (RF), were used to evaluate the performance of each features selection algorithm. The overall accuracies of the SVM and RF models revealed that three of the six algorithms exhibited higher ranks in landslide detection. Results indicated that the classification accuracies of the RF classifier were higher than the SVM classifier using either all features or only the optimal features. The proposed techniques performed well in detecting the landslides in a rainforest area of Malaysia, and these techniques can be easily extended to similar regions.

• Journal of Veterinary Clinics
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• v.36 no.1
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• pp.23-29
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• 2019

While research findings suggest that the highly pathogenic avian influenza (HPAI) is the leading cause of economic loss in Korean poultry industry with an estimated cumulative impact of $909 million since 2003, identifying the environmental and anthropogenic risk factors involved remains a challenge. The objective of this study was to identify areas at high risk for potential HPAI outbreaks according to the likelihood of HPAI virus detection in wild birds. This study integrates spatial information regarding HPAI surveillance with relevant demographic and environmental factors collected between 2003 and 2018. The Maximum Entropy (Maxent) species distribution modeling with presence-only data was used to model the spatial risk of HPAI virus. We used historical data on HPAI occurrence in wild birds during the period 2003-2018, collected by the National Quarantine Inspection Agency of Korea. The database contains a total of 1,065 HPAI cases (farms) tied to 168 unique locations for wild birds. Among the environmental variables, the most effective predictors of the potential distribution of HPAI in wild birds were (in order of importance) altitude, number of HPAI outbreaks at farm-level, daily amount of manure processed and number of wild birds migrated into Korea. The area under the receiver operating characteristic curve for the 10 Maxent replicate runs of the model with twelve variables was 0.855 with a standard deviation of 0.012 which indicates that the model performance was excellent. Results revealed that geographic area at risk of HPAI is heterogeneously distributed throughout the country with higher likelihood in the west and coastal areas. The results may help biosecurity authority to design risk-based surveillance and implementation of control interventions optimized for the areas at highest risk of HPAI outbreak potentials.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.5843-5847
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• 2013

Background: Persistent infection with high risk human papillomavirus (hrHPV) is strongly associated with cervical cancer. Normal cervical cells may also harbor hrHPV, and detection of early hrHPV infection may minimize risk of cervical cancer development. This study aimed to compare two commercial HPV genotyping assays that may affordable for early screening in a limited-resource setting in Bandung, Indonesia. Materials and Methods: DNA from cervical biopsies with histologically confirmed as squamous cell cervical cacinoma were HPV genotyped by Linear Assay 1 (Roche Diagnostics, Mannheim, Germany) or Linear Assay 2 (Digene HPV Genotyping RH Test, Qiagen Gaithersburg, MD). In a subset of samples of each group, HPV genotype results were then compared. Results: Of 28 samples genotyped by linear assay 1, 22 (78.6%) demonstrated multiple infections with HPV-16 and other hrHPV types 18, 45 and/or 52. In another set of 38 samples genotyped by linear assay 2, 28 (68.4%) were mostly single infections by hrHPV type 16 or 18. Interestingly, 4 samples that had been tested by both kits showed discordant results. Conclusions: In a limited-resource area such as in Indonesia, country with a high prevalence of HPV infection a reliable cervical screening test in general population for early hrHPV detection is needed. Geographical variation in HPV genotyping result might have impacts for HPV prevalence and molecular epidemiology as the distribution in HPV genotypes should give clear information to assess the impact of HPV prophylactic vaccines.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5133-5136
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• 2014

Objective: To use health economics methodology to assess the screening program on gastric cancer in Zhuanghe, China, so as to provide the basis for health decision on expanding the program of early detection and treatment. Materials and Methods: The expense of an early detection and treatment program for gastric cancer in patients found by screening, and also costs of traditional treatment in a hospital of Zhuanghe were assessed. Three major techniques of medical economics, namely cost-effective analysis (CEA), cost-benefit analysis (CBA) and cost-utility analysis (CUA), were used to assess the screening program. Results: Results from CEA showed that investing every 25, 235 Yuan on screening program in Zhuanghe area, one gastric cancer patient could be saved. Data from CUA showed that it was cost 1, 370 Yuan per QALY saved. Results from CBA showed that: the total cost was 1,945,206 Yuan with a benefit as 8,669,709 Yuan and an CBR of 4.46. Conclusions: The early detection and treatment program of gastric cancer appears economic and society-beneficial. We suggest that it should be carry out in more high risk areas for gastric cancer.

• Fire Science and Engineering
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• v.22 no.3
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• pp.265-271
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• 2008

This study analyzed on the area of Samcheok, Kangwondo about forest fire alarming area and enlargement of the area. Then, visible area by unattended watching camera and watchtower for forest fire which were run by Samcheok was cross-checked with geographic information system, and it ould be whether effective on watching the area here the forest fire risk was high enough and also it could be expanded to larger forest fire. The result of study, the visible area by watching facilities only holds for 13.4% of the whole forest fire alarming area, but the forest fire can be observed even though it is occurred in small valley because of smoke and all the forest fire have been occurred in daytime. Therefore, it can be determined that watching area will be extended around 50.3% while the observation radii of watching facilities raise by 4km. However, Samcheok has much greater area of mountain area in compared to any other cities or counties, watching facilities should be installed and run additionally for extinguishing the forest fire from the beginning.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.23-30
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• 2020

In this study, the relationship between natural gas (NG) data and gas-related environmental elements was performed using machine learning algorithms to predict the level of gas leakage risk without directly measuring gas leakage data. The study was based on open data provided by the server using the IoT-based remote control Picarro gas sensor specification. The naturel gas leaks into the air, it is a big problem for air pollution, environment and the health. The proposed method is multivariate outlier removing method based Random Forest (RF) classification for predicting risk of NG leak. After, unsupervised k-means clustering, the experimental dataset has done imbalanced data. Therefore, we focusing our proposed models can predict medium and high risk so best. In this case, we compared the receiver operating characteristic (ROC) curve, accuracy, area under the ROC curve (AUC), and mean standard error (MSE) for each classification model. As a result of our experiments, the evaluation measurements include accuracy, area under the ROC curve (AUC), and MSE; 99.71%, 99.57%, and 0.0016 for MOL_RF respectively.

• The Korean Journal of Pesticide Science
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• v.20 no.4
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• pp.286-292
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• 2016

Malaria is mainly transmitted by Anopheles sinensis which is dominant species in malaria high-risk area, northern part of Gyeonggi province in Korea. Pyrethroid insecticide is used for malaria vector, An. sinensis in Korea and the previous investigation consistently reported insecticide resistance from the vector. This study investigated insecticide susceptible and resistant alleles from An. sinensis and the status of malaria vector control in malaria high-risk area. For the study, An. sinensis collected from Paju, Gimpo and Ganghwa were sequenced for kdr detection. In Paju, there was no homozygous susceptibility and all of tested samples had homozygous or heterozygous resistance. There were 6.7% for susceptible homozygosity and 93.3% for resistant homozygosity or heterozygosity in Gimpo. Furthermore, the percentages of homozygous susceptibility and homozygous or heterozygous resistance in Ganghwa were 5.7% and 94.3% respectively. The results showed that the frequency of the insecticide resistance from An. sinensis in malaria high-risk area were increased much more than the previous investigation. Hence, this study suggests that malaria vector control programs should have to be prepared for the management of pyrethroid insecticide resistance.

• Journal of Chest Surgery
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• v.57 no.3
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• pp.302-311
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• 2024

Background: Unexpected conversion to thoracotomy during planned video-assisted thoracoscopic surgery (VATS) can lead to poor outcomes and comparatively high morbidity. This study was conducted to assess preoperative risk factors associated with unexpected thoracotomy conversion and to develop a risk scoring model for preoperative use, aimed at identifying patients with an elevated risk of conversion. Methods: A retrospective analysis was conducted of 1,506 patients who underwent surgical resection for non-small cell lung cancer. To evaluate the risk factors, univariate analysis and logistic regression were performed. A risk scoring model was established to predict unexpected thoracotomy conversion during VATS of the lung, based on preoperative factors. To validate the model, an additional cohort of 878 patients was analyzed. Results: Among the potentially significant clinical variables, male sex, previous ipsilateral lung surgery, preoperative detection of calcified lymph nodes, and clinical T stage were identified as independent risk factors for unplanned conversion to thoracotomy. A 6-point risk scoring model was developed to predict conversion based on the assessed risk, with patients categorized into 4 groups. The results indicated an area under the receiver operating characteristic curve of 0.747, with a sensitivity of 80.5%, specificity of 56.4%, positive predictive value of 1.8%, and negative predictive value of 91.0%. When applied to the validation cohort, the model exhibited good predictive accuracy. Conclusion: We successfully developed and validated a risk scoring model for preoperative use that can predict the likelihood of unplanned conversion to thoracotomy during VATS of the lung.

• Journal of agricultural medicine and community health
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• v.23 no.2
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• pp.193-204
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• 1998

Cardiovascular diseases are the leading cause of death and disability in Korea. Their risk factors can be classified as either modifiable or nonmodifiable and among modifiable factors are high bood pressure, elevated blood cholesterol, obesity and cigarette smoking. The purpose of this study was to evaluate the risk factors for the cardiovascular diseases in a rural community and to get basic data for the development of a community-based rick reduction intervention program. Evaluation involved population-based, cross-sectional samples of adult residents in a rurual community. We measured blood pressure, body fat percent by bioelectric impedance fatness analyzer and serum cholesterol and interviewed adult residents over 20-year-old age. Blood pressure was checked twice and hypertension was classified by the sixth report of the Joint National Committee on Detection. Evaluation, and Treatment of High Blood Pressure. The Cutpoints for high blood cholesterol was used National Cholesterol Treatment Guidelines and those for obesity was 25% in male. 30% in female. The results were as follows: 1. Prevalence of definitive hypertension was 59.7% in males and 54.4% in female. 2. Prevalence of hypercholesterolemia was 14.3% in male and 18.2% in female. 3. Prevalence of obese was 10.7% in male and 41.1% in female. 4. Among definitive hypertension, hypercholesterolemia, and obesity 52.1% possessed one risk factor, 12.6% two risk factors and 2.5% three risk factors in males. In females 41.4% possessed one risk factor and 27.6%. 5.7% respectively. 5. The smoking rate was 65.8% in males and 5.2% in females. Our results are used effectively for the community-based intervention towards cardiovascukr diseases risk reduction. However, because of limitations in our study design, further datas are needed including other risk factors and in-person clinical datas.

• Advances in nano research
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• v.15 no.5
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• pp.451-466
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• 2023

Gastrointestinal cancer (GC) is a prevalent malignant tumor of the digestive system that poses a severe health risk to humans. Due to the specific organ structure of the gastrointestinal system, both endoscopic and MRI diagnoses of GIC have limited sensitivity. The primary factors influencing curative efficacy in GIC patients are drug inefficacy and high recurrence rates in surgical and pharmacological therapy. Due to its unique optical features, good biocompatibility, surface effects, and small size effects, nanotechnology is a developing and advanced area of study for the detection and treatment of cancer. Because of its deep location and complex surgery, diagnosing and treating gastrointestinal cancer is very difficult. The early diagnosis and urgent treatment of gastrointestinal illness are enabled by nanotechnology. As diagnostic and therapeutic tools, nanoparticles directly target tumor cells, allowing their detection and removal. XGBoost was used as a classification method known for achieving numerous winning solutions in data analysis competitions, to capture nonlinear relations among many input variables and outcomes using the boosting approach to machine learning. The research sample included 300 GC patients, comprising 190 males (72.2% of the sample) and 110 women (27.8%). Using convolutional neural networks (CNN) and artificial neural networks (ANN)-EXtreme Gradient Boosting (XGBoost), the patients mean± SD age was 50.42 ± 13.06. High-risk behaviors (P = 0.070), age at diagnosis (P = 0.037), distant metastasis (P = 0.004), and tumor stage (P = 0.015) were shown to have a statistically significant link with GC patient survival. AUC was 0.92, sensitivity was 81.5%, specificity was 90.5%, and accuracy was 84.7 when analyzing stomach picture.