• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.4
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• pp.180-188
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• 2003

The vehicle simulator is a useful virtual reality system. The simulator enables engineers to effectively research and analyze various experiments. Therefore, the development of a specific vehicle simulator is required, and its performance must be verified. This paper verifies the performance of Pusan National University Vehicle Simulator. Human sensibility ergonomic tests of vehicle simulator were also executed. The sense of simulator motion was chosen as the standard of performance evaluation. The driver's senses were subdivided into senses of rectilinear and rotational velocities. This study extracted ergonomic sensibility words that can be used to evaluate the performance of the simulator As a practical application of simulator, the relation was studied between the sense of simulator motion and the characteristics of drivers, who are classified into their sexes and driving careers. A statistical method was applied to human sensibility ergonomic tests of vehicle simulator.

• Korean Journal of Remote Sensing
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• v.37 no.4
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• pp.665-685
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• 2021

This study focused on the a 20-year evaluation of the dynamism of critical thermal anomalies in Busan metropolitan area prompted by unusual infrastructural development and demographic growth rate. Archived Landsat thermal data derived-LST was the major input for UTFVI and hot spot analysis (Getis-Ord Gi^*). Results revealed that the surface urban heat island-affected area has gradually expanded overtime from 23.32% to 32.36%; while the critical positive thermal anomalies (level-3 hotspots) have also spatially increased from 19.88% in 2000 to 23.56% in 2020, recording a net LST difference of > 5℃ between the maximum level-3 hotspot and minimum level-3 coldspot each year. It is been observed that thermal conditions of Busan have gradually deteriorated with time, which is potentially inherent in the rate of urban expansion. Thus, this work serves as an eye-opener to powers that be, to think and act constructively towards a sustainable thermal conform for city dwellers.

• Journal of Oral Medicine and Pain
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• v.46 no.2
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• pp.41-48
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• 2021

Purpose: To evaluate compliance by analyzing and comparing treatment duration, degree of improvement after treatment and treatment response of oral lichen planus (OLP) patients according to characteristics of them and the severity of the lesion. Methods: According to treatment process, 132 subjects with OLP who first visited the Department of Oral Medicine at the Pusan National University Dental Hospital from January 2017 to December 2020were classified into three groups: Treatment completed (CT) group, Under treatment (UT) group, and Dropped out during follow-up (DT) group. The reticulation/keratosis, erythema, and ulceration (REU) scoring system was used to assess the severity of OLP. The degree of improvement after treatment was evaluated in CT group. Results: There were 53 (40.15%) CT, 27 (20.45%) UT and 52 (39.39%) DT. In CT group, according to initial REU score there was a statistical difference in the degree of improvement, but not in the length of time to complete treatment. There was no statistical difference between the days it took for patients to feel symptom relief, and the days of entire treatment among three groups. However, there was a positive correlation between the REU score of gingiva and duration of treatment in DT group. In the CT and DT groups, there was a correlation between the length of time taken to relieve symptoms and the duration of treatment. Conclusions: The severity of the gingival lesion and the initial response to treatment have a large effect on the entire treatment period and prognosis, so it should be considered when explaining the disease prognosis and treatment period to patients, and the clinician needs to focus on initial symptom relief.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.2
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• pp.71-78
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• 2016

The study of water environment system in Changnyeong-Haman weir section using a statistical analysis has been conducted. Statistical analyses used in this study were the correlation analysis, the principal components, and the factor analysis. The purpose of the study is to establish better understanding of relationships between water quality factors in the Changnyeong-Haman weir section which can provide useful information to manage Nakdong river. According to correlation analyses on COD and TOC, it revealed that the value of correlation coefficient was 0.844. Furthermore, the results from the principal component analysis categorized the water quality factors into three factor groups, the first principal factor group included COD, TOC, BOD, pH, water temperature (WT). And, it was observed that the concentration of cyanobacteria in the water body decreased, while the concentrations of the diatoms and the green algae increased after the events of rainfall.

• Journal of KIISE
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• v.41 no.11
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• pp.921-926
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• 2014

Face detection refers to the process extracting facial regions in an input image, which can improve speed and accuracy of recognition or authorization system, and has diverse applicability. Since conventional works have tried to detect faces based on the whole shape of faces, its detection performance can be degraded by occlusion made with accessories or parts of body. In this paper we propose a method combining local feature descriptors and probability modeling in order to detect partially occluded face effectively. In training stage, we represent an image as a set of local feature descriptors and estimate a statistical model for normal faces. When the test image is given, we find a region that is most similar to face using our face model constructed in training stage. According to experimental results with benchmark data set, we confirmed the effect of proposed method on detecting partially occluded face.

• Journal of the Korean Society of Clothing and Textiles
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• v.39 no.3
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• pp.408-418
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• 2015

This study investigates the purchasing and wearing conditions of wetsuits, and analyzes consumer awareness on wetsuit functional factors between domestic and imported brands. This research provides basic information on presenting competitiveness and developing suitable wetsuits for the Korean body shape through an investigation of a size system. An in-depth interview was conducted to consider consumer awareness with 10 persons of different levels of scuba diving experience. The survey variables consist of classified suggestion of inquires for functional factors and size systems. We distributed 80 questionnaires to scuba diving club members; subsequently, a total of 66 usable data sets were coded for statistical analysis through SPSS WIN 18.0. The result shows that respondents preferred imported ready-to-wear brands, whereas national ready-to-wear brands were purchased less often. However, the difference in customer awareness of functional factors between domestic and imported brands was not significant. In evaluating the size system of six brands (including three domestic and three imported brands), wetsuits of domestic brands were better fitted to the Korean body shape than imported brands; however, competitiveness has been hindered by public perception that domestic brands imitate imported brands. The results suggest that domestic brands can strengthen their competitiveness through promoting a lower price and size suited to Koreans while trying to change public perception as imitators of imported brands.

• Journal of Industrial Technology
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• v.30 no.A
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• pp.111-117
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• 2010

To improve the performance of the prediction system, the system should reflect well the uncertainty of nonlinear data. Thus, this paper presents multiple prediction systems based on Type-2 fuzzy sets. To construct each prediction system, an Interval Type-2 TSK Fuzzy Logic System and difference data were used, because, in general, it has been known that the Type-2 Fuzzy Logic System can deal with the uncertainty of nonlinear data better than the Type-1 Fuzzy Logic System, and the difference data can provide more steady information than that of original data. Also, to improve each rule base of the fuzzy prediction systems, the HCBKA (Hierarchical Correlation Based K-means clustering Algorithm) was applied because it can consider correlationship and statistical characteristics between data at a time. Subsequently, to alleviate complexity of the proposed prediction system, a system selection method was used. Finally, this paper analyzed and compared the performances between the Type-1 prediction system and the Interval Type-2 prediction system using simulations of three typical time series examples.

• Journal of Digital Convergence
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• v.12 no.6
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• pp.43-53
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• 2014

This study aims to improve the openness of administrative data and to make extensive use of it in the academic and policy development, analyzing the quality requirements as the users' view of administrative data using statistical purposes. Conducted the exploratory analysis on the case of the Transaction-based Price Index of Housing, applying the administrative data of Realestate Transaction Management System in Korea, based on Denmark's 7 quality indicators for the statistical use of administrative data. According to the results of this study, the administrative data could improve the efficacy of the policy by facilitating the collection of the statistical data which help analyzing the actual market situations. On the other hand, the data have some constraints in adding the required items to producing the statistics, or improving the timeliness problem, due to the characteristics focused on the civil service.

• Journal of the Korean Society of Systems Engineering
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• v.7 no.2
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• pp.21-30
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• 2011

The contractor management for the effective defense project is essential factor in the modern defense acquisition project. The occurrence of Improper Businessman causes the reason in which defense acquisition project is unable to be reasonably fulfilled and setback to the deployment of defense weapon system. In this paper, we develop a prediction model for the effective defense project by using the Discriminant Analysis, the Logistic Regression & Artificial Neural Network and analyse the core variables that determine the Improper Businessman in many variables. It is expected that our model can be used to improve the project management capability of defense acquisition and contribute to the establishment of efficient procurement procedure through entry of the reliable domestic manufacturer.

• Proceedings of the KIEE Conference
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• 1987.11a
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• pp.311-315
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• 1987

This paper describes the automatic visual inspect ion system of fabric defects based on pattern recognition techniques. To extract features for detection of fabric defects, four different techniques such as SGLDM. GCM, decorrelation method, and Laws' texture measure were investigated. From results of computer simulation, it has been found that GCM and decorrelation techniques provide good features. By employing a simple statistical pattern recognition technique, theaccuracy of classification of defect and nondefect was more than 90%. Some experimental results arm also presented.