• Communications for Statistical Applications and Methods
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• v.25 no.6
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• pp.633-645
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• 2018

Gaussian error distributions are a common choice in traditional regression models for the maximum likelihood (ML) method. However, this distributional assumption is often suspicious especially when the error distribution is skewed or has heavy tails. In both cases, the ML method under normality could break down or lose efficiency. In this paper, we consider the log-concave and Gaussian scale mixture distributions for error distributions. For the log-concave errors, we propose to use a smoothed maximum likelihood estimator for stable and faster computation. Based on this, we perform comparative simulation studies to see the performance of coefficient estimates under normal, Gaussian scale mixture, and log-concave errors. In addition, we also consider real data analysis using Stack loss plant data and Korean labor and income panel data.

• International journal of advanced smart convergence
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• v.12 no.1
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• pp.149-156
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• 2023

OOXML-based MS-Office digital files are extensively utilized by businesses and organizations worldwide. However, OOXML-based MS-Office digital files are vulnerable to forgery and corruption attack by including hidden suspicious information, which can lead to activating malware or shell code being hidden in the file. Such malicious code can cause a computer system to malfunction or become infected with ransomware. To prevent such attacks, it is necessary to analyze and detect the corruption of OOXML-based MS-Office files. In this paper, we examine the weaknesses of the existing OOXML-based MS-Office file structure and analyzes how concealment and forgery are performed on MS-Office digital files. As a result, we propose a system to detect hidden data effectively and proactively respond to ransomware attacks exploiting MS-Office security vulnerabilities. Proposed system is designed to provide reliable and efficient detection of hidden data in OOXML-based MS-Office files, which can help organizations protect against potential security threats.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.10
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• pp.4703-4723
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• 2016

The verification of data integrity is an urgent topic in remote data storage environments with the wide deployment of cloud data storage services. Many traditional verification algorithms focus on the block-oriented verification to resolve the dispute of dynamic data integrity between the data owners and the storage service providers. However, these algorithms scarcely pay attention to the data verification charge and the users' verification experience. The users more concern about the availability of accessed files rather than data blocks. Moreover, the data verification charge limits the number of checked data in each verification. Therefore, we propose a mixed verification protocol to verify the data integrity, which rapidly locates the corrupted files by the file-oriented verification, and then identifies the corrupted blocks in these files by the block-oriented verification. Theoretical analysis and simulation results demonstrate that the protocol reduces the cost of the metadata computation and transmission relative to the traditional block-oriented verification at the expense of little cost of additional file-oriented metadata computation and storage at the data owner. Both the opportunity of data extracted and the scope of suspicious data are optimized to improve the verification efficiency under the same verification cost.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.13
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• pp.5171-5174
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• 2014

Background: The increase in breast cancer awareness and widespread use of mammographic screening has led to an increased detection of (non-palpable) breast cancers that cannot be discovered through physical examination. One of the methods used in the diagnosis of these cancers is vacuum-assisted core biopsy, which prevents a considerable number of patients from undergoing surgical procedures. The aim of this study was to present the results of stereotactic vacuum-assisted core biopsy for suspicious breast lesions. Materials and Methods: Files were retrospectively scanned and data on demographic, radiological and pathological findings were recorded for patients who underwent stereotactic vacuum-assisted core biopsy due to suspicious mammographic findings at the Interventional Radiology Centre of the Florence Nightingale Hospital between January 2010, and April 2013. Statistical analysis was carried out using Pearson's Chi-square, continuity correction, and Fisher's exact tests. Results: The mean age of the patients was 47 years (range: 36-70). Biopsies were performed due to BIRADS 3 lesions in 8 patients, BIRADS 4 lesions in 77 patients, and BIRADS 5 lesions in 3 patients. Mammography elucidated clusters of microcalcifications in 73 patients (83%) and focal lesions (asymmetrical density, distortion) in 15 patients (17%). In terms of complications, 1 patient had a hematoma, and 2 patients had ecchymoses (3/88; 3.3%). The histopathologic results revealed benign lesions in 63 patients (71.6%) and malignant lesions in 25 patients (28.4%). The mean duration of the procedure was 37 minutes (range: 18-55). Although all of the BIRADS 3 lesions were benign, 22 (28.6%) of the BIRADS 4 lesions and all of the BIRADS 5 lesions were malignant. Among the malignant cases, 80% were in situ, and 20% were invasive carcinomas. These patients underwent surgery. Conclusions: In cases where non-palpable breast lesions are considered to be suspicious in mammography scans, the vacuum-assisted core biopsy method provides an accurate histopathologic diagnosis thus preventing a significant number of patients undergoing unnecessary surgical procedures.

• Child Health Nursing Research
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• v.19 no.1
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• pp.12-20
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• 2013

Purpose: The purpose of this study was to investigate factors associated with suspicious developmental delay in infants and early childhood. Methods: Participants were 133 infants, aged from birth to 6 years old and their mothers, who were being seen at 16 Public health centers in B city. Korean Denver II was used to test infant development. ${\chi}^2$-test, Fisher's exact test and multiple logistic regression were used with SPSS 19.0 to analyze data. Results: Of participant infants, 7.5% were below the 3rd percentile for the weight percentile, 8.4% is a weight curve that crosses more than 2 percentile lines on the growth charts after previous achievement, and 9.8% had suspicious developmental delay according to Korean Denver II. Further the predictive factors related to suspicious development delay in the children were decrease of weight percentile (Odds Ratio [OR]=6.69, Confidence Interval [CI])=1.22-36.45), low economic state (OR=6.26, CI=1.50-26.00), and development delay perceived by their mothers (OR=4.99, CI=1.24-20.06). Conclusion: It is necessary to build a government level system to follow management of development of infants and children from the time of birth. Especially, it is necessary to develop a program for children in low income families.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.5
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• pp.1715-1718
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• 2015

Background: Magnetic resonance imaging of breast, reported to be a high sensitivity of 94% to 100%, is the most sensitive method for detection of breast cancer. The purpose of this study was to investigate our clinical experience in MRI-guided breast lesion wire localization in Chinese women. Materials and Methods: A total of 44 patients with 46 lesions undergoing MRI-guided breast lesion localization were prospectively entered into this study between November 2013 and September 2014. Samples were collected using a 1.5-T magnet with a special MR biopsy positioning frame device. We evaluated clinical lesion characteristics on pre-biopsy MRI, pathologic results, and dynamic curve type baseline analysis. Results: Of the total of 46 wire localization excision biopsied lesions carried out in 44 female patients, pathology revealed fourteen malignancies (14/46, 30.4%) and thirty-two benign lesions (32/46, 69.6%). All lesions were successfully localized followed by excision biopsy and assessed for morphologic features highly suggestive of malignancy according to the American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) category of MRI (C4a=18, C4b=17, C4c=8,C5=3). Of 46 lesions, 37 were masses and 9 were non-mass enhancement lesions. Thirty-two lesions showed a continuous kinetics curve, 11 were plateau and 3 were washout. Conclusions: Our study showed success in MRI-guided breast lesion wire localization with a satisfactory cancer diagnosis rate of 30.4%. MRI-guided wire localization breast lesion open biopsy is a safe and effective tool for the workup of suspicious lesions seen on breast MRI alone without major complications. This may contribute to increasing the diagnosis rate of early breast cancer and improve the prognosis in Chinese women.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.8
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• pp.3411-3413
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• 2014

Background: Cytology for breast lesions is a safe, rapid and cost-effective with a high specificity and sensitivity. Objective: To determine the cytomorphologic patterns of breast lesions identified among a group of Sudanese patients. Materials and Methods: This study included 759 patients undergoing either a fine needle aspiration FNA, nipple discharge (ND) smears or breast skin scraping (SS) at a cytology clinic in Khartoum. Clinical and demographic data were reviewed. Stained smears were categorized into: inadequate sample, normal breast, benign lesion, suspicious, or malignant neoplasm. Results: Of the 759 cases, 734 (96.71%) were FNA, 18 (2.37%) ND and 7 cases (0.92%) SS. For 28 cases, FNA was done under ultrasound guidance. Females were 720 (94.86%). Benign lesions were 423 (55.75%) and 248 (32.67%) were malignant and 77 (10.14%) of smears were normal without any detected abnormality. Ten (1.31%) cases were suspicious for malignancy, and only one case (0.13%) was reported as inadequate. Most lesions were observed among the age group 30 years and above. Conclusions: Most patients investigated have benign lesions, one third of cytological smears were malignant. FNAC is a useful tool for investigating breast lesions in limited-resource settings.

• Journal of Minimally Invasive Surgery
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• v.21 no.4
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• pp.154-159
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• 2018

Purpose: Intussusception is a common cause of intestinal obstruction in children. While most patients can be treated by enema reduction, about 20% require surgery. We investigated the usefulness and feasibility of laparoscopic surgery and the intraoperative risk of bowel resection. Methods: We retrospectively reviewed pediatric patients who underwent surgery for intussusception from 2010 to 2017. We collected data for age, gender, body weight, associated symptoms, duration of symptoms, white blood cell count, operating time, and postoperative complications. Results: Of 155 patients, 37 (23.8%) underwent surgery due to enema reduction failure in 29 (78.3%), recurrence in 6 (16.3%), a suspicious lead point in 1, and suspicious ischemic change observed on ultrasonography in 1. The mean age was $26.8{\pm}18.9$ months (range, 3.5~76.7 months), and the mean body weight was $12.9{\pm}3.9kg$ (range, 5.4~22.2 kg). Laparoscopic surgery was successful in 29 patients (78.4%), and 7 (18.9%) needed bowel resection and anastomosis. The mean operating time was $56.7{\pm}32.8min$. A lead point was found in 3 patients in the bowel resection group (p=0.005); in addition, the operating time and hospital stay were longer in this group. There were no intra- or postoperative complications. Conclusion: Laparoscopic surgery was successful in 78.4% of the patients with a short hospital stay and early oral intake. The only predictive factor for bowel resection was the presence of a lead point. Laparoscopic surgery may be an optimal treatment intervention for children with intussusception, except for those who show initial peritonitis.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.438-441
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• 1996

Spinal deformity is a serious disease especially for teenagers and it is desirable for school children to be checked possible spinal deformity by moire photographic inspection method. The moire images of children's backs are visually inspected by doctors, which may cause misjudge because of a large amount of data they have to examine. A technique is proposed in this paper for automating this inspection by computer. Two characteristic axes, a potential symmetry axis approximating the human middle line and a principal axis representing the direction of a moire pattern are employed. Two principal axes are extracted locally on a back and their gradients against the potential symmetry axis are calculated. These gradients compose a 2D feature space and a linear discriminant function (LDF) is defined there which separates normal cases from suspicious cases. The LDF defined by 40 training, data was employed in the experiment to examine 40 test data and 77.5% of them were classified correctly. This amounts to 88.8% if the training data is included.

• The Korean Journal of Applied Statistics
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• v.28 no.1
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• pp.1-8
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• 2015

Security has become an issue due to the rapid increases in internet traffic data network. Especially P2P traffic data poses a great challenge to network systems administrators. Preemptive measures are necessary for network quality of service(QoS) and efficient resource management like blocking suspicious traffic data. Deep packet inspection(DPI) is the most exact way to detect an intrusion but it may pose a private security problem that requires time. We used several machine learning methods to compare the performance in classifying network traffic data accurately over time. The Random Forest method shows an excellent performance in both accuracy and time.