• Title/Summary/Keyword: Z-Score

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A Study on the Application of Outlier Analysis for Fraud Detection: Focused on Transactions of Auction Exception Agricultural Products (부정 탐지를 위한 이상치 분석 활용방안 연구 : 농수산 상장예외품목 거래를 대상으로)

  • Kim, Dongsung;Kim, Kitae;Kim, Jongwoo;Park, Steve
    • Journal of Intelligence and Information Systems
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    • v.20 no.3
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    • pp.93-108
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    • 2014
  • To support business decision making, interests and efforts to analyze and use transaction data in different perspectives are increasing. Such efforts are not only limited to customer management or marketing, but also used for monitoring and detecting fraud transactions. Fraud transactions are evolving into various patterns by taking advantage of information technology. To reflect the evolution of fraud transactions, there are many efforts on fraud detection methods and advanced application systems in order to improve the accuracy and ease of fraud detection. As a case of fraud detection, this study aims to provide effective fraud detection methods for auction exception agricultural products in the largest Korean agricultural wholesale market. Auction exception products policy exists to complement auction-based trades in agricultural wholesale market. That is, most trades on agricultural products are performed by auction; however, specific products are assigned as auction exception products when total volumes of products are relatively small, the number of wholesalers is small, or there are difficulties for wholesalers to purchase the products. However, auction exception products policy makes several problems on fairness and transparency of transaction, which requires help of fraud detection. In this study, to generate fraud detection rules, real huge agricultural products trade transaction data from 2008 to 2010 in the market are analyzed, which increase more than 1 million transactions and 1 billion US dollar in transaction volume. Agricultural transaction data has unique characteristics such as frequent changes in supply volumes and turbulent time-dependent changes in price. Since this was the first trial to identify fraud transactions in this domain, there was no training data set for supervised learning. So, fraud detection rules are generated using outlier detection approach. We assume that outlier transactions have more possibility of fraud transactions than normal transactions. The outlier transactions are identified to compare daily average unit price, weekly average unit price, and quarterly average unit price of product items. Also quarterly averages unit price of product items of the specific wholesalers are used to identify outlier transactions. The reliability of generated fraud detection rules are confirmed by domain experts. To determine whether a transaction is fraudulent or not, normal distribution and normalized Z-value concept are applied. That is, a unit price of a transaction is transformed to Z-value to calculate the occurrence probability when we approximate the distribution of unit prices to normal distribution. The modified Z-value of the unit price in the transaction is used rather than using the original Z-value of it. The reason is that in the case of auction exception agricultural products, Z-values are influenced by outlier fraud transactions themselves because the number of wholesalers is small. The modified Z-values are called Self-Eliminated Z-scores because they are calculated excluding the unit price of the specific transaction which is subject to check whether it is fraud transaction or not. To show the usefulness of the proposed approach, a prototype of fraud transaction detection system is developed using Delphi. The system consists of five main menus and related submenus. First functionalities of the system is to import transaction databases. Next important functions are to set up fraud detection parameters. By changing fraud detection parameters, system users can control the number of potential fraud transactions. Execution functions provide fraud detection results which are found based on fraud detection parameters. The potential fraud transactions can be viewed on screen or exported as files. The study is an initial trial to identify fraud transactions in Auction Exception Agricultural Products. There are still many remained research topics of the issue. First, the scope of analysis data was limited due to the availability of data. It is necessary to include more data on transactions, wholesalers, and producers to detect fraud transactions more accurately. Next, we need to extend the scope of fraud transaction detection to fishery products. Also there are many possibilities to apply different data mining techniques for fraud detection. For example, time series approach is a potential technique to apply the problem. Even though outlier transactions are detected based on unit prices of transactions, however it is possible to derive fraud detection rules based on transaction volumes.

Short-Term Complications of Percutaneous Endoscopic Gastrostomy according to the Type of Technique

  • Gang, Mi Hyeon;Kim, Jae Young
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.17 no.4
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    • pp.214-222
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    • 2014
  • Purpose: The method of percutaneous endoscopic gastrostomy (PEG) tube placement can be divided into the pull and introducer techniques. We compared short-term complications and prognosis between patients who underwent the pull technique and two other types of introducer techniques, the trocar introducer technique and T-fastener gastropexy technique. Methods: Twenty-six patients who underwent PEG were enrolled in this study. We retrospectively investigated the age, sex, body weight, weight-for-age Z-score, underlying diseases, PEG indications, complications, duration of NPO (nil per os), pain control frequency, and duration of antibiotic therapy. The patients were classified into three groups according to the PEG technique. The occurrence of complications was monitored for 10 weeks after the procedure. Results: The age, sex, body weight, and weight-for-age Z-score were not significantly between the three groups. Most patients had cerebral palsy and seizure disorders. Dysphagia was the most common indication for PEG. Major complications occurred in 5 (50%), 4 (66.7%), and 0 (0%) patients in group I, II, and III, respectively (p=0.005). Further, peristomal infection requiring systemic antibiotic therapy occurred in 2 (20%), 3 (50%), and 0 (0%) patients in group I, II, and III, respectively (p=0.04). There was no significant difference between the groups with respect to minor complications, duration of NPO, pain control frequency, and duration of antibiotic therapy. Conclusion: The results indicate that the T-fastener gastropexy technique was associated with the lowest rate of major complications.

Cognitive Contrast Enhancement of Image Using Adaptive Parameter Based on Non-Linear Masking (비선형 마스킹 기법 기반의 적응적 파라미터를 이용한 영상의 인지적 대비 향상)

  • Kim, Kyoung-Su;Kim, Jong-Sung;Lee, Cheol-Hee
    • Journal of Korea Multimedia Society
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    • v.14 no.11
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    • pp.1365-1372
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    • 2011
  • This paper proposes a cognitive contrast enhancement algorithm based on the non-linear masking to advance low cognitive contrast in dark regions of images. In order to improve brightness in dark regions of an image, we propose a new contrast enhancement algorithm based on the non-linear masking using regional adaptive parameters of an image. For performance evaluation of the proposed method, chromaticity and saturation comparison as a quantitative assessment and z-score comparison as a qualitative assessment were executed between test images and their simulated images by SSR, MSR, a conventional non-linear masking and the proposed method, respectively. As a result, the proposed method showed low chromaticity and saturation difference and improved cognitive contrast for the three methods.

The Effects of Laughter Therapy on Depression and Laughter Index in a Community-dwelling Aged (웃음치료 프로그램이 지역사회 노인의 우울과 웃음지수에 미치는 효과)

  • Kim, Jinju;Kang, Gyun Young;Ju, Sejin
    • Journal of East-West Nursing Research
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    • v.20 no.2
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    • pp.160-166
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    • 2014
  • Purse: The purpose of this study was to examine the effect of a laughter therapy on mental health promoting like depression, laughing index of elderly. Methods: The study was conducted based on the non-equivalent control group pretest-posttest design. The participations included 12 older adults in the control group and 11 in the experiment group. Data was collected from October 1 to November 22, 2013. Experimental group participated in laughter therapy six times, once a week for 60 minutes of each session. Questionnaires were used to measure pretest and posttest levels of depression and laughing index. Results: At the end of six-week intervention, depression score (z=-2.95 p=.003) and laughter index score (z=-2.81 p=.005) was significantly decreased in the experimental group compared to the control group. Futhermore, there was a significant difference in the depression scores of the experiment group at the posttest, but no signigicant difference was found between the two groups. Conclusion: The study results suggest that the laughter therapy is an effective intervention to reduce the depression but helpful to enhance the laughing index. Therefore, it is expected that laughter therapy will serve as an emotional nursing intervention for elderly patients with depression.

Interlaboratory Study for Proficiency Testing on the Water Toxicity Determinations by Acute Toxicity Test with Daphnia magna (국내 생태독성 분석기관에 대한 숙련도시험 결과 평가)

  • Kim, Jongmin;Shin, Kisik;Yu, Soonju;Kim, Myeong Ock;Choe, Sung Hun
    • Journal of Korean Society on Water Environment
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    • v.30 no.6
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    • pp.632-637
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    • 2014
  • Proficiency testing by interlaboratory comparisons is used to determine the performance of individual laboratories. In order to verify the quality of acute toxicity testing with Daphnia magna, National Institute of Environmental Research in South Korea is regularly organizing interlaboratory comparisons to estimate the analytical accuracy of different laboratories. Total 58 laboratories located in South Korea took part in interlaboratory proficiency testing scheme with three proficiency testing samples. TU(Toxic Unit) values of each laboratory were determined and robust z-score was calculated in order to evaluate the proficiency levels. Based on the robust z-score classification, 74% of the participant laboratories showed a satisfactory performance (43 laboratories). The main reason of 'unsatisfactory' performance seemed to be considered that the unsuitable management of test organism incubation system and the lack of experience on the identification of the test organism condition by effect of toxicity.

Effects of Betaine on Performence, Carcass Characteristics and Hepatic Betaine-homocysteine Methyltransferase Activity in Finishing Barrows

  • Feng, J.;Liu, X.;Wang, Y.Z.;Xu, Z.R.
    • Asian-Australasian Journal of Animal Sciences
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    • v.19 no.3
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    • pp.402-405
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    • 2006
  • This experiment was conducted to determine the effect of dietary betaine (0, 0.125%) on performance, carcass composition, pork quality and hepatic betaine-homocysteine methyltransferase (BHMT) activity of crossbred finishing barrows. Three replicates of ten pigs were used for each treatment. The results showed that average daily gain, feed intake and feed conversion were not affected by betaine. Compared with the control group, pigs treated with betaine had a 8.17% (p<0.05) decrease in carcass fat percentage, and a 8.84% (p<0.05) reduction in 10th-rib backfat thickness, but dressing percentage, percentage lean, longissimus muscle area, and average backfat thickness were not affected. There were also no significant differences in muscle color score, marbling score, pork pH value and water loss rate between the control and betaine-treated groups. Hepatic betaine-homocysteine methyltransferase (BHMT) activity was significantly increased by 13.97% (p<0.05) when pigs were offered 0.125% betaine.

The Effects of Somatosensory Stimulation on Cognitive Function and ADL of Patients after Stroke (체감각자극이 뇌졸중 환자의 인지기능과 일상활동 수행능력에 미치는 효과)

  • Kim, Dae-Ran;Hur, Hea-Kung
    • Korean Journal of Adult Nursing
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    • v.20 no.2
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    • pp.239-250
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    • 2008
  • Purpose: The purpose of this study was to determine the effect of a 2-week somatosensory stimulation program on cognitive function and ADL of patients with brain damage. Methods: The sample consisted of two groups of patients with stroke: 10 patients with a mean age of 59.0 years who were treated with somatosensory stimulation, and 9 patients with a mean age of 51.78 years, who were not treated with somatosensory intervention. A nonequivalent control group non-synchronized design was used to assess the functional recovery after stroke. Instruments used in this study were MMSE-K for cognitive function and FIM for ADL. Results: The hypothesis 1 that "Patients with stroke who were treated with the somatosensory stimulation program will show higher MMSE-K score than that of the non-treatment group" was supported(Z = -2.390, p = .017). The hypothesis 2 that "Patients with stroke who were treated with the somatosensory stimulation program will show higher FIM score than that of the non-treatment group", however, was partially supported(social cognition: Z = -2.204, p = .045). Conclusion: Somatosensory stimulation was effective to patients with stroke in improving their cognitive function. These findings suggest that somatosensory input can be adopted to nursing intervention for functional recovery after stroke.

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Board Structure and Likelihood of Financial Distress: An Emerging Asian Market Perspective

  • UD-DIN, Shahab;KHAN, Muhammad Yar;JAVEED, Anam;PHAM, Ha
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.241-250
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    • 2020
  • This study examines the relationship between the attributes of board structure and the likelihood of financial distress for the non-financial sector of an emerging market characterized by concentrated ownership and family-controlled business. The present study utilized panel logistic regression to estimate the relationship between board structure attributes and the likelihood of financial distress. We used Altman Z-Score as a proxy for firm financial distress, as this tool measures the financial distress inversely. The study finds a significant relationship between board size and the likelihood of financial distress. The results show that a one-unit increase in board size would decrease the probability of financial distress by 3.4%. Further, we observe that a greater level of board independence is associated with a lower likelihood of financial distress. A one-unit increase in board independence would decrease the probability of financial distress by 20.4%. We also find a significant positive impact of leverage on the likelihood of financial distress. The present study contributes to the body of literature on board structure attributes and likelihood of financial distress in emerging markets, like Pakistan. Furthermore, the findings would be beneficial for corporate policymakers and investors in formulating corporate financial strategy and predicting business failure.

Effect of Ownership Structure on Bank Diversification and Risk-Taking Behavior in Bangladesh

  • MOUDUD-UL-HUQ, Syed;BISWAS, Tanmay;CHAKRABORTY, Brishti;AMIN, Md. Al
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.11
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    • pp.647-656
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    • 2020
  • This study empirically examines the effect of ownership structure on bank diversification and risk-taking behavior. The population of this study is based on all commercial banks listed in Bangladesh. Thirty-two conventional commercial banks were randomly selected from thirty-three conventional banks for this study. Data was collected from the annual reports of the concerned banks from 2000 to 2017. To analyze the data, we had applied the two-stage least squares (2SLS) estimator. The results of the analysis show that ownership structure i.e. managerial ownership, institutional ownership, general public ownership, and ownership concentration have a significant negative impact on bank diversification. On the other hand, institutional ownership, managerial ownership, and general public ownership have a significant positive impact on Z-score, and ownership concentration has an insignificant but positive impact on the Z-score of banks in Bangladesh. Therefore, the study opposes the benefits of diversification and promotes ownership structure which is capable of ensuring better financial stability by reducing the probability of risk. The policy-makers especially, Bangladesh banks should evaluate the fact of this study to issue guidelines on corporate governance, bank diversification, and risk-taking behavior of commercial banks.

Effect of 360-degree Hospitalization Guide Video Content for ICU Caregivers on Anxiety, Satisfaction and Safety Perception

  • Park, Jung-Ha;Lee, Yun-Bok
    • International journal of advanced smart convergence
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    • v.10 no.4
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    • pp.233-240
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    • 2021
  • The purpose of this study was to provide a 360-degree video on intensive care unit admission guidance to family members admitted to the intensive care unit, and then to identify anxiety, safety perception, and satisfaction. This study was a single-group pre-post design, and the data collection period was from October 1, 2020 to August 30, 2021. The subjects of this study were 19 people who applied 360 degree hospitalization guide video. For data analysis, SPSS WIN 24.0 program was used, and real number, percentage, mean, standard deviation, minimum value, maximum value, and Wilcoxon signed rank test were used. The subjects' anxiety before intervention was an average score of 6.21±2.30 and the anxiety after intervention was an average score of 3.95±2.46, which was statistically significant (z=4.13, p<.001). The safety consciousness of the subjects before the intervention was an average of 4.08±0.39 and the safety consciousness after the intervention was an average of 4.54±0.48, which was statistically significant (z=5.00, p=.001). The highest level of satisfaction with the 360-degree hospitalization guidance image of the subjects was 4.58±0.51 and the lowest was 4.16±0.96. In this study, when 360-degree hospitalization guide video was applied, there was a difference in anxiety and safety perception, and satisfaction was high. Based on the research results, various programs for guardian education can be developed and utilized in the future.