• Journal of the Korea Convergence Society
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• v.11 no.9
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• pp.1-6
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• 2020

In this study, we propose an association inference model based on data bias optimization for road hazard detection. This is a mining model based on association analysis to collect user's personal characteristics and surrounding environment data and provide traffic accident prevention services. This creates transaction data composed of various context variables. Based on the generated information, a meaningful correlation of variables in each transaction is derived through correlation pattern analysis. Considering the bias of classified categorical data, pruning is performed with optimized support and reliability values. Based on the extracted high-level association rules, a risk detection model for personal characteristics and driving road conditions is provided to users. This enables traffic services that overcome the data bias problem and prevent potential road accidents by considering the association between data. In the performance evaluation, the proposed method is excellently evaluated as 0.778 in accuracy and 0.743 in the Kappa coefficient.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.4
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• pp.235-243
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• 2021

River surveying is conducted to acquire basic geographic data for river master plans and various river maintenance, and it is also used to predict changes after river maintenance construction. ABL (Airborne Bathymetric LiDAR) system is a cutting-edge surveying technology that can simultaneously observe the water surface and river bed using a green laser, and has many advantages in river surveying. In order to use the ABL data for river surveying, it is prerequisite step to segment and extract the water surface and river bed points from the original point cloud data. In this study, point cloud segmentation was performed by applying the ground filtering technique, ATIN (Adaptive Triangular Irregular Network) to the ABL data and then, the water surface and riverbed point clouds were extracted sequentially. In the Gokgyocheon river area, Chungcheongnam-do, the experiment was conducted with the dataset obtained using the Leica Chiroptera 4X sensor. As a result of the study, the overall classification accuracy for the water surface and riverbed was 88.8%, and the Kappa coefficient was 0.825, confirming that the ABL data can be effectively used for river surveying.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.36 no.6
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• pp.589-599
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• 2018

The land cover map has been produced by using satellite and aerial images. However, these two images have the limitations in spatial resolution, and it is difficult to acquire images of a area at desired time because of the influence of clouds. In addition, it is costly and time-consuming that mapping land cover map of a small area used by satellite and aerial images. This study used multispectral camera-based drone to acquire multi-temporal images for orthoimages generation. The efficiency of produced land cover map was evaluated using time series analysis. The results indicated that the proposed method can generated RGB orthoimage and multispectral orthoimage with RMSE (Root Mean Square Error) of ${\pm}10mm$, ${\pm}11mm$, ${\pm}26mm$ and ${\pm}28mm$, ${\pm}27mm$, ${\pm}47mm$ on X, Y, H respectively. The accuracy of the pixel-based and object-based land cover map was analyzed and the results showed that the accuracy and Kappa coefficient of object-based classification were higher than that of pixel-based classification, which were 93.75%, 92.42% on July, 92.50%, 91.20% on October, 92.92%, 91.77% on February, respectively. Moreover, the proposed method can accurately capture the quantitative area change of the object. In summary, the suggest study demonstrated the possibility and efficiency of using multispectral camera-based drone in production of land cover map.

• Journal of Christian Education in Korea
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• v.66
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• pp.383-412
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• 2021

The purpose of this study is to analyze the journal of reflection of students who participated in the character improvement education program. And it is a study that suggests ways to develop the program according to the results of analysis. Then, by collecting 208 reflective journals of students who participated in Milal training at K University, After the analysis was performed in the process of transcription, coding, and subject discovery, reliability was secured by calculating the Kappa coefficient for the analysis frame and analysis suitability. According to the results of the analysis of reflection journal. Through Milal training, the Milal spirit was understood as sacrificial service (sacrifice, devotion, lowering, serving, death, decay) and Milal (reproduction). We confirmed that It will have a life attitude related to the themes of labor (hardwork, work, patience, patience, perseverance). It can be said that through Milal training, self-reflection activities can be promoted, community character and collaboration skills can be cultivated, and the spirit of sacrificial service can be acquired. Through the results of this reflection journal analysis, it is necessary to further enhance the Milal training program, and it will be possible to provide implications to the character cultivation programs of other universities.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.827-835
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• 2023

Drone light detection and ranging (LiDAR) is a state-of-the-art surveying technology that enables close investigation of the top of the mountain slope or the inaccessible slope, and is being used for field surveys in mountainous terrain. To build topographic information using Drone LiDAR, a preprocessing process is required to effectively separate ground and non-ground points from the acquired point cloud. Therefore, in this study, the point group data of the mountain topography was acquired using an aerial LiDAR mounted on a commercial drone, and the application and accuracy of the cloth simulation filtering algorithm, one of the ground separation techniques, was verified. As a result of applying the algorithm, the separation accuracy of the ground and the non-ground was 84.3%, and the kappa coefficient was 0.71, and drone LiDAR data could be effectively used for landslide field surveys in mountainous terrain.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.3
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• pp.307-314
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• 2013

Objectives: The aim of this study was to determine the prevalence of symptoms relating to musculoskeletal disorders (MSDs) and investigate the risk factors among researchers at university laboratories. Methods: 209 researchers were included in this study, drawn from 27 laboratories at three universities in Korea. Checklists for MSD symptoms and risk factor assessment were utilized. Results: The symptoms checklist showed reliable results with Cohen's Kappa 0.33-0.56, percent agreement 81.0-96.8%, and correlation coefficient 0.41-0.63. The overall prevalence of MSD symptoms was 68.9%, while the prevalence in specific parts of body were as follows: shoulders (47.6%), lower back (46.9%), neck (46.9%), knees (25.4%), wrists (20.1%), elbows (13.6%). The symptom prevalence among women was higher than among men (OR 2.67, 95% CI 1.37-5.18). Daily exposure time was observed to be a significant risk factor for developing MSD symptoms (OR 2.14-6.07). Conclusions: This study suggested that repetitive pipetting and static work posture are the most significant risk factors for MSD symptoms among laboratory researchers.

• The Journal of Internal Korean Medicine
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• v.35 no.4
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• pp.483-497
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• 2014

Objectives: The aims of study were developing cut-off value of Yin-deficiency questionnaire (YDQ) for diagnosis of Yin-deficiency (YD) and compare diagnostic ability between YDQ and Yin-deficiency scale score (YDS) in xerostomia patients. Methods: We recruited 58 xerostomia patients. They were diagnosed YD or non-YD by 3 Korean medicine doctors (KMD). We assessed YD using YDQ and YDS. We evaluated xerostomia using VAS, Dry Mouth Symptom Questionnaire (DMSQ), Salivary Flow Rate (SFR), oral moisture on buccal mucosa and tongue surface (OMB and OMT). We surveyed tongue coatings using Winkel Tongue Coating Index (WTCI). Results: We diagnosed 23 patients YD and 35 patients non-YD. There were no significant differences of age, sex and body mass index between the YD and non-YD groups. Using receiver operating characteristic curve analysis, the optimal cut-off value of YDQ was defined as 304. Sensitivity, specificity and Youden index of YDQ were 86.96%, 71.43% and 1.5839 respectively. Using Cohen's coefficient of agreement, we found that degree of agreement between KMD and YDQ diagnosis was moderate (${\kappa}$=0.524, p<0.001). Using Pearson's correlation analysis, we found concurrent validity of YDQ and YDS were significant correlated. Using area under curve value, we found diagnostic ability between YDQ and YDS were not significantly different (p=0.505), but there were more strong correlations between DMSQ-symptoms and YDQ (r=0.731, p<0.001) than correlations between DMSQ-symptoms and YDS (r=0.418, p<0.01). Conclusions: The cut-off value of YDQ can diagnose YD in xerostomia and diagnostic ability of YDQ in xerostomia is better than YDS.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.403-406
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• 2005

In order to evaluate the Capability of ETM+ remotely- sensed data to provide 'Forest-shrub land-Rangeland' cover type map in areas near the timberline of northern forests of Iran, the data were analyzed in a portion of nearly 790 ha located in Neka-Zalemroud region. First, ortho-rectification process was used to correct the geometric errors of the image, yielding 0/68 and 0/69 pixels of RMS. error in X and Y axis, respectively. The original and panchromatic bands were fused using PANSHARP Statistical module. The ground truth map was made using 1 ha field plots in a systematic-random sampling grid, and vegetative form of trees, shrubs and rangelands was recorded as a criteria to name the plots. A set of channels including original bands, NDVI and IR/R indices and first components of PCI from visible and infrared bands, was used for classification procedure. Pair-wise divergence through CHNSEL command was used, In order to evaluate the separability of classes and selection of optimal channels. Classification was performed using ML classifier, on both original and fused data sets. Showing the best results of $67\%$ of overall accuracy, and 0/43 of Kappa coefficient in original data set. Due to the results represented above, it's concluded that ETM+ data has an intermediate capability to fulfill the spectral variations of three form- based classes over the study area.

• International Journal of Contents
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• v.11 no.4
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• pp.31-37
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• 2015

The objectives of this study were: 1) to determine smartphone addiction, visual display terminal syndrome (VDTS) related symptoms, and state anxiety among adolescents, and 2) to identify the relationship among these variables. Data were collected via selfadministrated questionnaire survey from May to June, 2013. The survey was carried out with 540 voluntary participants at 13 to 24 years old from middle schools, high schools, and universities in Korea. The presence and severity of smartphone addiction, VDTS symptoms, and state anxiety were measured using Korean Smartphone Addiction Proneness Scale, VDTS Questionnaire, and State Anxiety Inventory, respectively. Data were analyzed by Cohen’s Kappa coefficient, Kruskal-Wallis test, and Mann-Whitney U test. The mean score of smartphone addiction for all students was 2.17 ± 0.51. The mean scores of smartphone addiction depending on school grade were 2.12 ± 0.53, 2.03 ± 0.48, and 2.42 ± 0.43 for middle school, high school, and college students, respectively. Subjects who experienced minor level of VDTS symptoms had a score of 0.49 ± 0.49 for VDTS symptoms. The score was increased when the level of addiction was higher. There were significant differences in VDTS subjective symptoms among smartphone addiction groups (p<.001). High-risk group of smartphone addiction had the highest scores in every subdomain of VDTS symptoms. Differences were also found in state anxiety among the three groups with smartphone addiction. The findings of this study showed that approximately one out of three adolescents might be classified into problematic smartphone users. Therefore, it is important to educate problematic smartphone users about smartphone addiction and VDTS symptoms to prevent further addiction and aggravation of anxiety.

• Physical Therapy Korea
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• v.19 no.4
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• pp.46-54
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• 2012

Ely's test is commonly used to assess rectus femoris muscle flexibility. however, a reliability limit of this test was demonstrated by a previous study. In this study, we present an alternative method using an application for a digital horizontal level in a smartphone (DHLS) to complement the reliability limit of Ely's test. The aim of this study was to examine the reliability of Ely's test using DHLS on the pelvis, compared to using visual observation (VO) of pelvic and hip motions. Nineteen patients with lumbar extension-rotation syndrome were recruited for this study. An examiner examined the rectus femoris flexibility (both pass/fail and goniometer scoring) through Ely's test using both DHLS and VO. A retest session was completed two hours later for within-day reliability and seven days later for between-day intra-rater test-retest reliability. Results showed higher Kappa values for pass/fail scoring and higher intraclass correlation coefficient values for goniometer scoring in Ely's test using DHLS, compared to using VO. Measurement error and Bland and Altman plots further demonstrated the degree of intra-rater variance during Ely's test using DHLS in a clinical setting, compared to using VO. These results demonstrated that Ely's test using DHLS showed acceptable reliability compared to using VO. Ely's test using DHLS could be widely used for measuring the rectus femoris muscle flexibility in patients with lumbar extension-rotation syndrome, although the inter-rater reliability needs to be established first.