• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.33 no.4
• /
• pp.671-685
• /
• 2023

By applying artificial intelligence to image editing technology, it has become possible to generate high-quality images with minimal traces of manipulation. However, since these technologies can be misused for criminal activities such as dissemination of false information, destruction of evidence, and denial of facts, it is crucial to implement strong countermeasures. In this study, image file and mobile forensic artifacts analysis were conducted for detecting image manipulation. Image file analysis involves parsing the metadata of manipulated images and comparing them with a Reference DB to detect manipulation. The Reference DB is a database that collects manipulation-related traces left in image metadata, which serves as a criterion for detecting image manipulation. In the mobile forensic artifacts analysis, packages related to image editing tools were extracted and analyzed to aid the detection of image manipulation. The proposed methodology overcomes the limitations of existing graphic feature-based analysis and combines with image processing techniques, providing the advantage of reducing false positives. The research results demonstrate the significant role of such methodology in digital forensic investigation and analysis. Additionally, We provide the code for parsing image metadata and the Reference DB along with the dataset of manipulated images, aiming to contribute to related research.

• Korean Journal of Culture and Social Issue
• /
• v.14 no.4
• /
• pp.1-18
• /
• 2008

The present study examined the accuracy of polygraph tests through two types of statistical methods with unknown ground truth. One method evaluated the accuracy based on the rates of agreements between polygraph test results of crime suspects and prosecutors' indictment decisions for them. Those crime suspects were tested with polygraph by the Prosecutors' Office of the Republic of Korea between 2000 and 2004. The other method estimated the accuracy by using the latent class analysis based on the frequency distributions of the polygraph results and indictments during 2006. Excluding cases that were 'inconclusive' on the polygraph test, the study showed that the accuracy of the polygraph tests is .914 (SE=.004) for the 2000-2004 data, and .885 (SE=.021) for the 2006 data. With the inclusion of 'inconclusive' cases in the 2006 data, the results from the latent class analysis showed the accuracy in the range between .707 and .734 (SE=.027~.031), with false positives between .078 and .087 (SE=.019~.023), and false negatives between .029 and .078 (SE=.010~.023). The probability that the polygraph test correctly classifies subjects appeared to be in the range between .912 and .925 (SE=.013-.016) for those who lie, and in the range between .867 to .955 (SE=.011-.040) for those who tell the truth.

• Journal of the Korean Society of Radiology
• /
• v.82 no.5
• /
• pp.1186-1195
• /
• 2021

Purpose In the adult emergency department of a university hospital, we investigated the frequency of major discrepancies between the preliminary reports by radiology residents and the final reports by certified radiologists. Materials and Methods Based on CT and MRI scans obtained between December 2016 and November 2019, we selected cases with diagnoses or treatment plans that could be changed due to discrepancies between preliminary and final reports and classified them by the type of discrepancy. We also examined the distributions of the major discrepancies and stratified them by residents' working time zone, experience, and subspecialty. Results Based on the 72137 preliminary reports evaluated, 1348 tests (1.9%) showed major discrepancies. Most of the major discrepancies were false negatives (72.0%), followed by misdiagnosis (26.3%) and false positives (1.7%). Acute findings (87.2%) were more common than non-acute findings (12.8%). The major discrepancy rate increased toward the second half of the 24-hour shift, with the highest rate of 2.9% occurring between 2 am and 4 am. The major discrepancy rate did not vary with experience, and it varied from 0.6% to 4.5% for each subspecialty. Conclusion The major discrepancy rate was less than 2%, and it increased with longer working hours during a 24-hour shift.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.26 no.4
• /
• pp.17-34
• /
• 2023

Camera trapping has been used as a non-invasive survey method that minimizes anthropogenic disturbance to ecosystems. Nevertheless, it is labor-intensive and time-consuming, requiring researchers to quantify species and populations. In this study, we aimed to improve the preprocessing of camera trapping data by utilizing an object detection algorithm. Wildlife monitoring using unmanned sensor cameras was conducted in a forested urban forest and a green space on a university campus in Cheonan City, Chungcheongnam-do, Korea. The collected camera trapping data were classified by a researcher to identify the occurrence of species. The data was then used to test the performance of the YOLO-X object detection algorithm for wildlife detection. The camera trapping resulted in 10,500 images of the urban forest and 51,974 images of green spaces on campus. Out of the total 62,474 images, 52,993 images (84.82%) were found to be false positives, while 9,481 images (15.18%) were found to contain wildlife. As a result of wildlife monitoring, 19 species of birds, 5 species of mammals, and 1 species of reptile were observed within the study area. In addition, there were statistically significant differences in the frequency of occurrence of the following species according to the type of urban greenery: Parus varius(t = -3.035, p < 0.01), Parus major(t = 2.112, p < 0.05), Passer montanus(t = 2.112, p < 0.05), Paradoxornis webbianus(t = 2.112, p < 0.05), Turdus hortulorum(t = -4.026, p < 0.001), and Sitta europaea(t = -2.189, p < 0.05). The detection performance of the YOLO-X model for wildlife occurrence was analyzed, and it successfully classified 94.2% of the camera trapping data. In particular, the number of true positive predictions was 7,809 images and the number of false negative predictions was 51,044 images. In this study, the object detection algorithm YOLO-X model was used to detect the presence of wildlife in the camera trapping data. In this study, the YOLO-X model was used with a filter activated to detect 10 specific animal taxa out of the 80 classes trained on the COCO dataset, without any additional training. In future studies, it is necessary to create and apply training data for key occurrence species to make the model suitable for wildlife monitoring.

• Parasites, Hosts and Diseases
• /
• v.29 no.3
• /
• pp.293-310
• /
• 1991

Clonorchis sinensis is a common parasite of man in Korea. Researches on the specific antigens of C. sinensis would be valuable not only because those elucidate the molecular characteristics of this fluke but also because it is applicable to immunodiagnosis. Although many monoclonal antibodies have been used in the field of parasite immunology, few articles on monoclonal antibodies against C. sinensis have been published so far. The aim of this study was to analyse C. sinensis antigens recognized by monoclonal antibodies, and to set up ELISA-inhibition test using C. sinensis specific monoclonal antibodies for improved specificity of immunodiagnostic tests. By fusion between spleen cells of the mice immunized with C. sinensis water-soluble crude adult worm antigens and plasmacytoma cells of mouse origin, 29 hybridoma clones secreting anti-C. sinensis monoclonal antibodies were made, and 8 clones among those were found specific. After cell cloning, isotypes of 6 selected specific monoclonal anti- bodies were determined to be IgGl, IgG2b and IgA. Four exposed antigenic determinants of natural infection were recognized by different specific monoclonal antibodies. By enzyme-immunoelectrotransfer blot, 10 KD, 34 KD antigenic determinants were found to be reacted with CsHyb 0714-20, CsHyb 0605-10 monoclonal antibodies, respectively, The antigenic determinant recognized by CsHyb 0714-20 monoclonal antibody was revealed to be located at the surface and parenchyme of a parasite by indirect immunoauorescent antibody technique, and those reacted with CsHyb 0605-10, CsHyb 0714-25 monoclonal antibodies were found at the parenchyme and intestine. The antigenic determinant reacted with CsHyb 0605-23 monoclonal antibody was found mainly around the uterine eggs. Four antigenic determinants recognized by specific monoclonal antibodies were all found to be present in the early eluted fractions of C. sinensis antigens separated by Sephadex G-200 gel filtration. By conventional ELISA, 75% of clonorchiasis cases were found positive, but 7.1% of normal controls and 37.5% of paragonimiasis cases showed false positives. However, by ELISA-inhibition test using C. sinensis specific monoclonal antibody (CsHyb 0605-23), 77.1% of clonorchiasis cases were found positive, and there were no false positives in normal controls or paragonimiasis cases, indicating 100% specificity. The ELISA- inhibition test using monoclonal antibodies was found to have same sensitivity and definitely high specificity in comparison with conventional ELISA for serodiagnosis of human clonorchiasis.

• Microbiology and Biotechnology Letters
• /
• v.43 no.3
• /
• pp.296-299
• /
• 2015

Cowpea mild mottle virus (CPMMV) has a wide range of hosts, such as the pea family and tomato. CPMMV is a non-reported virus in Korea, and is domestically designated as a controlled virus associated with plant quarantine. In this study, a rapid diagnostic method for the detection of CPMMV at quarantine sites was developed. For the development of a user-based system, the PCR compositions and conditions use existing methods of quarantine for the viruses. Two sets of RT-PCR and nested PCR were developed in this study that could be amplified from 579 → 298 dp and 638 → 252 bp, respectively. Furthermore, a sequence inserted positive control plasmid was developed, which is able to identify false-positives resulting from laboratory contamination. The findings of this study are important for the diagnosis of CPMMV in imported crops held in plant quarantine.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.49 no.3
• /
• pp.227-231
• /
• 2004

A total of 219 polymerase chain reaction tests of genetically modified (GM) DNA sequences in soybean seeds and soybean sprouts were conducted during 2000-2001. No CM gene was found in 96 tests of soybean seeds. However, either a functional CP4EPSPS gene or the 355 promoter gene was found three times in 2000 and eight times in 2001, in between 0.01 and 0.17％ of soybean spout products, in 123 tests. Since the amount of GM genes was much less than the threshold limit of 3％, none of the 11 positive soybean-sprout samples needed to be libeled GM crops. Of these, seven sprout samples were from domestic seeds and four were from seeds imported from China. To find the contamination route, the raw materials, seed surface, floor of the storage room, area around the selection machine, surface of the packaging film and corn powder used in the package were tested. The 35S promoter gene was detected in only two samples of the corn powder (0.1％). Although we could not find the cause of the GM contamination, the sprout package film is one possibility. In total,8.9％ of the soybean sprout tests were GM positive, but the amounts were much less than the threshold of 3％. This means that there are frequent false-positives and these would threaten the sprout industry if GMO were decided qualitatively. Food companies should make their safety data available to the public and make an effort to address people's concerns about GM food more openly. In addition, there is a need to establish a quantitative test for GM genes in sampled water and a sampling method for raw materials.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.5
• /
• pp.451-457
• /
• 2020

Format recognition and OCR techniques are widely used as methods for detecting and protecting personal information from electronic documents. However, due to the poor recognition rate of the OCR engine, personal information cannot be detected or false positives commonly occur. It also takes a long time to analyze a large amount of electronic documents. In this paper, we propose a method to improve the speed of image analysis of electronic documents, character recognition rate of the OCR engine, and detection rate of personal information by improving the existing method. The analysis speed was increased using the format recognition method while the analysis speed and character recognition rate of the OCR engine was improved by image correction. An algorithm for analyzing personal information from images was proposed to increase the reconnaissance rate of personal information. Through the experiments, 1755 image format recognition samples were analyzed in an average time of 0.24 seconds, which was 0.5 seconds higher than the conventional PAID system format recognition method, and the image recognition rate was 99%. The proposed method in this paper can be used in various fields such as public, telecommunications, finance, tourism, and security as a system to protect personal information in electronic documents.

• Asian Pacific Journal of Cancer Prevention
• /
• v.15 no.16
• /
• pp.6571-6574
• /
• 2014

Background: Alcohol is well established as a risk factor for cancer development in many organ sites. To assess the reliability and validity of the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) for detecting alcohol use disorders or risky drinking in Japanese adults the present study was conducted. Materials and Methods: A test-retest method was applied with a 2-week interval with 113 health care employees. The k coefficient, Cronbach's coefficient alpha, Spearman's correlation coefficient, and intraclass correlation coefficient (ICC) were determined and the validity of the AUDIT-C was analyzed using the data from a nationwide survey on adult alcohol use conducted in 2008 (n=4,123). Results: The reliability of the AUDIT-C score was high (${\kappa}$ coefficient=0.63, Cronbach's alpha=0.98, correlation coefficient=0.95, and ICC=0.95). According to the likelihood ratio and Youden index, appropriate cutoffs for the AUDIT-C were ${\geq}5points$ in men and ${\geq}4$ points in women. The sensitivity and specificity of these cutoffs for identifying ${\geq}8$ points on the AUDIT were 0.88 and 0.80, respectively, for men (positive likelihood ratio [LR+]=4.5) and 0.96 and 0.87, respectively, for women (LR+=7.7). The sensitivity and specificity of the cutoffs for identifying ${\geq}12$ points on the AUDIT were 0.90 and 0.84, respectively, for men (LR+=5.8) and 0.93 and 0.94, respectively, for women (LR+=15.8). The sensitivity and specificity of the cutoffs for identifying ${\geq}16$ points on the AUDIT were 0.93 and 0.80, respectively, for men (LR+=4.7) and 0.92 and 0.98, respectively, for women (LR+=55.6). With higher scores on the AUDIT, the specificity decreased and false-positives increased. The appropriate cutoffs for identifying risky drinking were the same for both genders. Conclusions: The reliability and validity of the AUDIT-C are high, indicating that it is useful for identifying alcohol use disorders or risky drinking among the general population in Japan, a group at high risk of cancer development.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.2
• /
• pp.263-269
• /
• 2008

Hydrazinocurcumin (HC), a synthetic derivative of curcumin, has been reported to inhibit angiogenesis via unknown mechanisms. Understanding the molecular mechanisms of the drug's action is important for the development of improved compounds with better pharmacological properties. A genome-wide drug-induced haploinsufficiency screening of fission yeast gene deletion mutants has been applied to identify drug targets of HC. As a first step, the 50% inhibition concentration $(IC_{50})$ of HC was determined to be $2.2{\mu}M$. The initial screening of 4,158 mutants in 384-well plates using robotics was performed at concentrations of 2, 3, and $4{\mu}M$. A second screening was performed to detect sensitivity to HC on the plates. The first screening revealed 178 candidates, and the second screening resulted in 13 candidates, following the elimination of 165 false positives. Final filtering of the condition-dependent haploinsufficient genes gave eight target genes. Analysis of the specific targets of HC has shown that they are related to septum formation and the general transcription processes, which may be related to histone acetyltransferase. The target mutants showed 65% growth inhibition in response to HC compared with wild-type controls, as shown by liquid culture assay.