• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.36 no.2
• /
• pp.51-58
• /
• 2018

Recently, various satellite sensors have been developed and it is becoming more convenient to acquire multitemporal satellite images. Therefore, various researches are being actively carried out in the field of utilizing change detection techniques such as disaster and land monitoring using multitemporal satellite images. In particular, researches related to the development of unsupervised change detection techniques capable of extracting rapidly change regions have been conducted. However, there is a disadvantage that false detection occurs due to a spectral difference such as a seasonal change. In order to overcome the disadvantages, this study aimed to reduce the false alarm detection due to seasonal effects using the direction vector generated by applying the $S^2CVA$ (Sequential Spectral Change Vector Analysis) technique, which is one of the unsupervised change detection methods. $S^2CVA$ technique was applied to RapidEye images of the same and different seasons. We analyzed whether the change direction vector of $S^2CVA$ can remove false positives due to seasonal effects. For the quantitative evaluation, the ROC (Receiver Operating Characteristic) curve and the AUC (Area Under Curve) value were calculated for the change detection results and it was confirmed that the change detection performance was improved compared with the change detection method using only the change magnitude vector.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.12 no.4
• /
• pp.405-413
• /
• 1987

In this paper, we have discussed three-type median filters(SQUARE, CROSS, X-SHAPE) that preserving edge in an original image while reducing random noise was introduced for image enhancement and edge detection on radar image. Since radar image have a number of parts of curve, we compared results produced by edge detection operater proposed for improving the parts of curve with results of using the existing edge detection methods, such as Roberts, Sobel, Prewitt, Laplacian and Kirsch.

• Proceedings of the IEEK Conference
• /
• summer
• /
• pp.274-275
• /
• 2004

The Hough transform has been used as a tool for line detection. The main idea of the Hough transform is to transform each pixel in the image individually into the parameter domain. In this way, the Hough transform converts a difficult global detection problem in the image domain into a more easily solved local peak detection problem in the parameter domain. In this paper, we show that the discrete Hough transform is identical to the discrete Radon transform. Thus, we can use the generalized Radon transform to handle more general parameterized curve types.

• Journal of information and communication convergence engineering
• /
• v.21 no.1
• /
• pp.98-102
• /
• 2023

This paper presents a study on how augmenting semi-synthetic image data improves the performance of human detection algorithms. In the field of object detection, securing a high-quality data set plays the most important role in training deep learning algorithms. Recently, the acquisition of real image data has become time consuming and expensive; therefore, research using synthesized data has been conducted. Synthetic data haves the advantage of being able to generate a vast amount of data and accurately label it. However, the utility of synthetic data in human detection has not yet been demonstrated. Therefore, we use You Only Look Once (YOLO), the object detection algorithm most commonly used, to experimentally analyze the effect of synthetic data augmentation on human detection performance. As a result of training YOLO using the Penn-Fudan dataset, it was shown that the YOLO network model trained on a dataset augmented with synthetic data provided high-performance results in terms of the Precision-Recall Curve and F1-Confidence Curve.

• Journal of the Korean Data and Information Science Society
• /
• v.14 no.2
• /
• pp.313-323
• /
• 2003

For the growth curve model with arbitrary covariance structure, known as unstructured covariance matrix, the problems of detecting outliers are discussed in this paper. In order to detect outliers in the growth curve model, the test statistics using U-distribution is established. After detecting outliers in growth curve model, we test homo and/or hetero-geneous covariance matrices using PSR Quasi-Bayes Criterion. For illustration, one numerical example is discussed, which compares between before and after outlier deleting.

• Journal of the Korea Society of Computer and Information
• /
• v.23 no.4
• /
• pp.57-64
• /
• 2018

In this paper, we propose the automatic detection method for individual region separation using panorama image. Finding areas that contain individual teeth is one of the most important tasks in automating 3D models through individual tooth separation. In the conventional method, the maxillary and mandibular teeth regions are separated using a straight line or a specific CT slide, and the tooth regions are separated using a straight line in the vertical direction. In the conventional method, since the teeth are arranged in a curved shape, there is a problem that each tooth region is incorrectly detected in order to generate an accurate tooth region. This is a major obstacle to automating the creation of individual tooth models. In this study, we propose a method to find the correct tooth curve by using the jawbone curve which is very similar to the tooth curve in order to overcome the problem of finding the area containing the existing tooth. We have proposed a new method to accurately set individual tooth regions using the feature that individual teeth are arranged in a direction similar to the normal direction of the tooth alignment curve. In the proposed method, the maxillary and mandibular teeth can be more precisely separated than the conventional method, and the area including the individual teeth can be accurately set. Experiments using real dental CT images demonstrate the superiority of the proposed method.

• International Journal of Highway Engineering
• /
• v.9 no.3
• /
• pp.29-38
• /
• 2007

This study investigated the effects of delineation systems on drivers' maneuver and how the effectiveness of delineation system can be further improved according to the road geometry. The experiments were conducted to collect lateral placement data and detection distance data using GPS equipped vehicles. The main results are summarizedas follows. Firstly, installing the delineation facilities on the roads helps drivers to recognize road alignment. Secondly, the detection distance is longer for delineators than for raised pavement marker in tangent section, while there is no difference in curve section. The chevron show the longest detection distance in the curve section, while the raised pavement markers showed no distinctive performance in terms of detection distance and lateral placement. Therefore, we can recommend install delineators in the tangent sections and chevrons in curve sections, based on the analysis results of effects of delineation facilities.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.30 no.6
• /
• pp.1076-1081
• /
• 2001

Gamma-irradiated peanuts, Korean and Chinese origins, were investigated on detection properties by thermoluminescence (TL), electron spin resonance (ESR), and DNA comet assay (single cell gel electrophoresis). TL measurement showed that the non-irradiated sample revealed a glow curve with low intensity at about 25$0^{\circ}C$, while the irradiated samples showed higher intensity around at 18$0^{\circ}C$. TL ratio (TL$_1$/TL$_2$) of area for TL$_1$ glow curve to TL$_2$ was below 0.05 for the non-irradiated sample and 0.2 or more for the irradiated ones, thus identifying each other. ESR spectroscopy for the irradiated peanuts using outer skin showed negligible signals induced by irradiation, indicating ESR is little applicable to the detection of irradiated peanuts. In DNA comet assay, the non-sample had no or very short tails, whereas the irradiated samples revealed the cells with long tails. Significance in the increase of their lengths depending on irradiation dose (r=0.761/Korean, r=0.768/Chinese) was also found. There was no remarkable difference in detection properties by origins of samples in all determinations, It is concluded that TL analysis or DNA comet assay is suitable for detection of irradiated peanuts and a combined method is recommendable for enhancing the reliability of detection results.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.8
• /
• pp.3451-3455
• /
• 2015

Objective: To explore the application of joint detection of serum AFP, CA19-9, CA125 and CEA in identification and diagnosis of cholangiocarcinoma (CC). Materials and Methods: The levels of serum AFP, CA19-9, CA125 and CEA of both 30 patients with CC and 30 patients with hepatocellular carcinoma (HCC) were assessed. Receiver operating characteristic (ROC) curves were used to evaluate the diagnostic effects of single and joint detection of those 4 kinds of tumor markers for CC. Results: The levels of serum CA19-9, CA125 and CEA in CC patients were higher than that in HCC patients,whereas that of serum AFP was significantly lower s. The area under ROC curve of single detection of serum AFP, CA19-9, CA125 and CEA were 0.05, 0.86, 0.84 and 0.83, with the optimal cutoff values of 15.4 ng/ml, 125.1 U/ml, 95.7 U/ml and 25.9 ng/ml, correspondingly, and the percentage correct single diagnosis was <79%. With joint detection, the diagnostic effect of combined AFP, CA19-9, CA125 and CEA was the highest, with an area under the ROC curve of 0.94 (95%CI 0.88~0.99). Conclusions: Single detection of serum CA19-9, CA125 and EA is not meaningful. The sensitivity, specificity, the rate of correct diagnosis and the area under ROC curve of joint detection of AFP, CA19-9, CA125 and CEA are highest, indicating that the joint detection of these 4 tumor markers is of great importance in the diagnosis of CC.

• Imaging Science in Dentistry
• /
• v.34 no.1
• /
• pp.1-5
• /
• 2004

Purpose: To evaluate the diagnostic accuracy of occlusal and proximal caries detection using CCD, CMOS, PSP and film system. Materials and Methods : 32 occlusal and 30 proximal tooth surfaces were radiographed under standardized conditions using 3 digital systems; CCD (CDX-2000HQ, Biomedysis Co., Seoul, Korea), CMOS (Schick, Schick Inc., Long Island, USA), PSP (Digora/sup (R)/FMX, Orion Co./Soredex, Helsinki, Finland) and I film system (Kodak Insight, Eastman Kodak, Rochester, USA). 5 observers examined the radiographs for occlusal and proximal caries using a 5-point confidence scale. The presence of caries was validated histologically and radiographically. Diagnostic accuracy was evaluated using ROC curve areas (Az). Results: Analysis using ROC curves revealed the area under each curve which indicated a diagnostic accuracy. For occlusal caries, Kodak Insight film had an Az of 0.765, CCD one of 0.730, CMOS one of 0.742 and PSP one of 0.735. For proximal caries, Kodak Insight film had an Az of 0.833, CCD one of 0.832, CMOS one of 0.828 and PSP one of 0.868. No statistically significant difference was noted between any of the imaging modalities. Conclusion: CCD, CMOS, PSP and film performed equally well in the detection of occlusal and proximal dental caries. CCD, CMOS and PSP-based digital images provided a level of diagnostic performance comparable to Kodak Insight film.