• Journal of The Korean Society of Agricultural Engineers
• /
• v.61 no.3
• /
• pp.55-65
• /
• 2019

Although crack on concrete exists from its early formation, crack requires attention as it affects stiffness of structure and can lead demolition of structure as it grows. Detecting cracks on concrete is needed to take action prior to performance degradation of structure, and deep learning can be utilized for it. In this study, transfer learning, one of the deep learning techniques, was used to detect the crack, as the amount of crack's image data was limited. Pre-trained Inception-v3 was applied as a base model for the transfer learning. Web scrapping was utilized to fetch images of concrete wall with or without crack from web. In the recognition of crack, image post-process including changing size or removing color were applied. In the visualization of crack, source images divided into 30px, 50px or 100px size were used as input data, and different numbers of input data per category were applied for each case. With the results of visualized crack image, false positive and false negative errors were examined. Highest accuracy for the recognizing crack was achieved when the source images were adjusted into 224px size under gray-scale. In visualization, the result using 50 data per category under 100px interval size showed the smallest error. With regard to the false positive error, the best result was obtained using 400 data per category, and regarding to the false negative error, the case using 50 data per category showed the best result.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.14
• /
• pp.5889-5897
• /
• 2015

Background: The performance of combined testing visual inspection with acetic acid (VIA) and cervical cytology tests might differ from one setting to another. The average estimate of the testing accuracy across studies is informative, but no meta-analysis has been carried out to assess this combined method. Objective: The objective of this study was to estimate the average sensitivity and specificity of the combined VIA and cervical cytology tests for the detection of cervical precancerous lesions. Materials and Methods: We conducted a systematic review and a meta-analysis, according to the Cochrane Handbook for Systematic Review of Diagnostic Test Accuracy. We considered two cases. In the either-positive result case, a positive result implies positivity in at least one of the tests. A negative result implies negativity in both tests. In the both-positive case, a positive result implies having both tests positive. Eligible studies were identified using Pubmed, Embase, Website of Science, CINHAL and COCRANE databases. True positive, false positive, false negative and true negative values were extracted. Estimates of sensitivity and specificity, positive and negative likelihood (LR) and diagnostic odds ratios (DOR) were pooled using a hierarchical random effect model. Hierarchical summary receiver operating characteristics (HSROC) were generated and heterogeneity was verified through covariates potentially influencing the diagnostic odds ratio. Findings: Nine studies fulfilled inclusion criteria and were included in the analysis. Pooled estimates of the sensitivities of the combined tests in either-positive and both-positive cases were 0.87 (95% CI: 0.83-0.90) and 0.38 (95% CI: 0.29-0.48), respectively. Corresponding specificities were 0.79 (95% CI: 0.63-0.89) and 0.98 (95% CI: 0.96-0.99) respectively. The DORs of the combined tests in either-positive or both-positive result cases were 27.7 (95% CI: 12.5-61.5) and 52 (95% CI: 22.1-122.2), respectively. When including only articles without partial verification bias and also a high-grade cervical intraepithelial neoplasia as a threshold of the disease, DOR of combined test in both-positive result cases remained the highest. However, DORs decreased to 12.1 (95% CI: 6.05-24.1) and 13.8 (95% CI: 7.92-23.9) in studies without partial verification bias for the combined tests in the either-positive and both-positive result cases, respectively. The screener, the place of study and the size of the population significantly influenced the DOR of combined tests in the both-positive result case in restriction analyses that considered only articles with CIN2+ as disease threshold. Conclusions: The combined test in the either-positive result case has a high sensitivity, but a low specificity. These results suggest that the combined test should be considered in developing countries as a primary screening test if facilities exist to confirm, through colposcopy and biopsy, a positive result.

• The Korean Journal of Cytopathology
• /
• v.8 no.2
• /
• pp.120-128
• /
• 1997

Fine needle aspiration cytology of breast lesion is well known as a simple, economic and effective diagnostic modality. For the evaluation of cytohistologic correlation, 256 cases of cytologic smears and subsequent histologic sections during 2-year period from Jan. 1995 to Dec. 1996 were reviewed. 1. Fifteen cases(5.9%) were proven as insufficient for evaluation, and 13 of them were fibrocystic change histologically. One case of carcinoma exhibiting sufficient amount of aspirates with no malignant cells on smear was regarded as inadequate. 2. Cytohistologic correlation of 240 cases revealed sensitivity 87.0%, specificity 100.0%, positive predictive value 100.0%, negative predictive value 97.0%, false positive rate 0.0% and false negative rate 13.0%. Total diagnostic accuracy is 95.7%. 3. Total 6 cases of negative were due to small amount of aspirates containing scantiness of malignant cells in two and underestimation in four. 4. Diagnostic concordance rates of fibrocystic change and fibroadenoma were 95.5% and 80.0%, respectively. Diagnostic discrepancies were noted in 7 cases of fibrocystic change and 6 cases of fibroadenoma, however, cytologic discrimination of two entities was not easy in seven of them. 5. In a case of phyllodes tumor and a case of duct ectasia, the discrepancy was due to targeting error. Other three cases(lymphoma, adenomyoepithelioma and granulomatous mastitis) were misinterpreted because of poor acquaintance with those entities. Diagnostic accuracy of fine needle aspiration cytology of breast lesions are relatively high. However, good technique on aspiration and adequate interpretation are necessary to reduce the false negative rate and the discrepancy between cytologic and histologic diagnoses.

• The Korean Journal of Nuclear Medicine
• /
• v.34 no.1
• /
• pp.94-98
• /
• 2000

We report a false positive case of I-131 scan due to a sialolithiasis in right submandibular gland. I-131 images showed not only remnant thyroid tissues and functional metastases in the anterior neck but also a hot uptake near right submandibular gland. We confirmed the sialolithiasis by radiologic studies. Sialolithiasis should be regarded as a false positive cause when I-131 scan shows a hot spot near salivary bed.

• The KIPS Transactions:PartD
• /
• v.13D no.1 s.104
• /
• pp.111-116
• /
• 2006

Given a state, it is essential to for the finite state model analysis (such as model checking) to decide whether or not the state is reachable. W a site of the model is small, the whole state space is to be explored exhaustively. However, it is very difficult or even impossible if a size of the model is large. In this case, the model can be reduced into a smaller one via abstraction which does not allow e false positive error. this paper, we devise such an abstraction and apply it to the Nemorize game solving. As a result, unsolved game due to the state explosion problem is solved with the proposed abstraction.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.21 no.4
• /
• pp.222-226
• /
• 2011

This study was conducted to identify the characteristics of analytical errors shown in the Korean quality control program on bulk asbestos analyses using polarized light microscopy (PLM). 179 participating laboratories were required to analyze 4 samples respectively and asked to classify each test sample as asbestos-containing (positive) or non-asbestos-containing (negative). For positive samples, participants were also asked to identify the type and semiquantitate the contents of asbestos present. The test results showed 21 (4%) false negative errors among 562 samples, 9 (6%) false positive errors among 154 samples and 53 (9%) asbestos identification errors among 562 samples. Most of false negative and positive errors were observed in a few types of samples. Higher frequencies of asbestos identification errors were shown in samples containing two or more types of asbestos and samples containing anthophyllite, tremolite or actinolite asbestos. For semiquantitative analyses, the ratios of mean to nominal weight contents were 2.1 for chrysotile and 2.9 for amphiboles. A tendency of over-estimation was observed in semiquantitative analyses using the visual estimation technique and higher in case of analyzing samples containing amphiboles than chrysotile. Coefficients of variation (CVs) of semiquantitative analytical results were 0.44~0.83 and 0.5~1.14 for samples containing chrysotile and amphibole asbestos, respectively.

• The Korean Society of Law and Medicine
• /
• v.13 no.1
• /
• pp.41-69
• /
• 2012

First introduced in 1977, Korean health care system reached to national coverage in short period of time never seen before in any other countries, and rated as successful system protecting the health of the public at relatively low price. However, despite those positive evaluations, some of fraudulent medical organizations or pharmacies are hindering the sound development of the national health care system with meticulous false billing exaggerating the number of patients or the days of their treatment. To prevent aforementioned nursing home fraud and false billing, the misconduct should be punished as subject to the criminal law and severally punished for fines and payments which far exceed the expected amount of illicit gains as it is basically violation of criminal fraud, other than the forced return of illicit gains based on civil laws. Furthermore, the Health Insurance Review and Assessment Service should strengthen and complement the fraud investigators, the review process, and the professional training to raise the detection rates. It might also want to review ways to implement whistleblower rewarding system and rewards for evidences of healthcare fraud to overcome the limits of external review.

• Journal of Yeungnam Medical Science
• /
• v.3 no.1
• /
• pp.179-183
• /
• 1986

The frozen section technique is a means of intraoperative pathological diagnosis, and a procedure of great value to the surgeon. This method should be accurate, rapid and reliable. This method serves useful purposes, such as determining the presence of tumor, its type(especially whether it is benign or malignant), the adequacy of a biopsy of a suspected lesion, and the conditions of the surgical margins. But, it bears many disadvantages, the most of which is the danger of incorrect diagnosis. We studied the indications, the limitations, and the accuracy of the frozen section method and the materials studies was total of frozen section during recent 3 years. The overall accuracy of the frozen section diagnosis of 809 cases was 98.1% with 0.5% of false negative, 0% of false positive, 0.5% of incorrect histological diagnosis or grading errors, and 0.9% of deferred cases. The tissues submitted were lymph node, gastrointestinal tract, skin subcutaneous tissues in decreasing oder of frequency. The false positive case is not present, while the false negative cases were 4.

• Korean Journal of Radiology
• /
• v.21 no.7
• /
• pp.891-899
• /
• 2020

Objective: To assess the diagnostic performance of a deep learning-based algorithm for automated detection of acute and chronic rib fractures on whole-body trauma CT. Materials and Methods: We retrospectively identified all whole-body trauma CT scans referred from the emergency department of our hospital from January to December 2018 (n = 511). Scans were categorized as positive (n = 159) or negative (n = 352) for rib fractures according to the clinically approved written CT reports, which served as the index test. The bone kernel series (1.5-mm slice thickness) served as an input for a detection prototype algorithm trained to detect both acute and chronic rib fractures based on a deep convolutional neural network. It had previously been trained on an independent sample from eight other institutions (n = 11455). Results: All CTs except one were successfully processed (510/511). The algorithm achieved a sensitivity of 87.4% and specificity of 91.5% on a per-examination level [per CT scan: rib fracture(s): yes/no]. There were 0.16 false-positives per examination (= 81/510). On a per-finding level, there were 587 true-positive findings (sensitivity: 65.7%) and 307 false-negatives. Furthermore, 97 true rib fractures were detected that were not mentioned in the written CT reports. A major factor associated with correct detection was displacement. Conclusion: We found good performance of a deep learning-based prototype algorithm detecting rib fractures on trauma CT on a per-examination level at a low rate of false-positives per case. A potential area for clinical application is its use as a screening tool to avoid false-negative radiology reports.

• Journal of the Korea Convergence Society
• /
• v.11 no.10
• /
• pp.139-146
• /
• 2020

Kastle-Meyer (KM) test is one of presumptive tests used to detect latent blood in crime scenes. While this method is more sensitive than others, false positive reaction can be shown where blood does not exist. In this study, we tried to suggest a new application method to solve this problem. Reaction time and aspect of reaction of this new method was compared with two conventional methods in order to identify the effectiveness and identifiability. As a result, there was no statistically significant difference in sensitivity between the methods. In addition, in case of blood with a dilution ratio of 5000:1 or less, positive reaction showed immediately, making it easy to distinguish the reaction from false positive reaction. However, it became difficult to distinguish them with the reaction time as the dilution ratio increased, and this phenomenon could be supplemented observing aspect of the reaction when using the new method. Therefore, this study suggested a new method for KM test that can be used more accurately in the field.