• Title/Summary/Keyword: Risk Rating

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Relationship Between Internet Addiction and Circadian Rhythm in Adults (성인 인터넷 중독과 일주기 리듬의 연관성)

  • Kang, Do Won;Soh, Minah;Lee, Tae Kyeong
    • Sleep Medicine and Psychophysiology
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    • v.22 no.2
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    • pp.57-63
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    • 2015
  • Background and Objectives: Internet addiction is an increasing problem in Korea. The previous studies in this area have targeted adolescents and young adults. This study was conducted to examine the risk of internet addiction in Korean adults and the effect of internet addiction on circadian rhythm. Materials and Methods: For this study, 508 subjects were chosen through population proportional sampling to represent the adult population in Korea, 325 of whom were included based on the Alcohol Use Disorder Identification Test-Korea (Audit-K), Zung's Self-Rating Depression Scale (SDS), drug use in the past year, and suicide attempts. In these subjects, sociodemographic factors including age, gender, and residential area were analyzed, and Young's Internet Addiction Scale (IAS), Morningness-Eveningness Questionnaire (MEQ), and an online survey examining sleep onset time on weekdays and weekends, wake-up time, and caffeinated drink intake were executed. Results: Of the 325 subjects, 136 (41.8%) belonged to a high-risk internet addiction group ($IAS{\geq}40$), and 189 (58.2%) belonged to a normal group (IAS < 40). There was a high proportion of male subjects (p = 0.03) in the high-risk group compared to the normal group. There was a high proportion of younger subjects (p = 0.055) in the high-risk group compared to the normal group, but this difference was not statistically significant. Compared to the normal group, there was a high proportion of the evening type ($MEQ{\leq}41$) in the high-risk group (p = 0.024), who also showed a high proportion of caffeinated drink intake (p < 0.001). Also, the high-risk group was found to go to bed and wake up late, but there was no statistically significant difference with the normal group. Conclusion: This study showed that many adults have a high-risk of internet addiction, and there was a significant correlation between internet addiction and sleep in adult, as has been found in adolescents and early adults. In the future, a longitudinal study will be needed to verify the causal relationship between internet addiction and morningness-eveningness.

The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

Comparison of improvement on Low back pain depending on male inpatient's Pulse wave velocity (남성 입원환자들의 맥파속도에 따른 요통 호전도의 비교 연구)

  • Lee, Jin-Hyuk;Sui, Mu-Chang;Min, Kwan-Sik;Lee, Han;Jeong, Ho-Seok
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.4 no.2
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    • pp.39-45
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    • 2009
  • Objectives : The aim of this study is to compare the improvement of Low back pain (LBP) depending on male Inpatient's Brachlalankle Pulse Wave Velocity (baPWV), Method : We evaluated 35 LBP inpatients who took pulse wave velocity test during admission at Jaseng hospital from November 2008 to september 2009. We used applanation tonometry method to measure pulse wave velocity and numerical rating scale to measure patient's improvement. Result : At admission, standard deviation of normal group's NRS was $7.44{\pm}1.67$ and high risk group's was $7.57{\pm}2.09$(P=0.678). After 5 days of admission, standard deviation of normal group's NRS was $5.67{\pm}1.94$ and high risk group's was $6.00{\pm}2.17$(P=0.680). After 10 days of admission, standard deviation of normal group's NRS was $4.00{\pm}1.80$ and high risk group's was $4.95{\pm}1.96$(P=0.281). After 15 days of admission, standard deviation of normal group's NRS was $2.89{\pm}1.62$ and high risk group's was $4.10{\pm}1.92$(P=0.124). At discharge, standard deviation of normal group's NRS was $5.11{\pm}1.69$ and high risk group's was $4.86{\pm}2.08$(P=0.504). Comparison between admission and discharge, standard deviation of normal group's NRS was $5.11{\pm}1.69$ and high risk group's was $4.86{\pm}2.08$(P=0.504) Conclusion : Low back patients with high Brachialankle Pulse Wave Velocity, showed slower improvement rate compare to patients within normal rate. But statically, had no significance.

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Behavior Analysis and Control of a Moored Training Ship in an Exclusive Wharf (전용부두 계류중인 실습선의 선체거동 해석 및 제어에 관한 연구)

  • Cho, Ik-Soon
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.23 no.2
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    • pp.139-145
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    • 2017
  • Recently, gusts, typhoon and tsunamis have been occurring more frequently around the world. In such an emergency situation, a moored vessel can be used to predict and analyze other vessel behavior, but if the mooring system is destroyed, marine casualties can occur. Therefore, it is necessary to determine quantitatively whether a vessel should be kept in the harbour or evacuate. In this study, moored ship safety in an exclusive wharf according to swell effects on motion and mooring load have been investigated using numerical simulations. The maximum tension exerted on mooring lines exceeded the Safety Working Load for intervals 12 and 15 seconds. The maximum bollard force also exceeded 35 tons (allowable force) in all evaluation cases. The surge motion criteria result for safe working conditions exceeded 3 meters more than the wave period 12 seconds with a wind speed of 25 knots. As a result, a risk rating matrix (risk category- very high risk, high risk and moderate risk) was developed with reference to major external forces such as wind force, wave height and wave periods to provide criteria for determining the control of capabilities of mooring systems to prevent accidents.

A Prospective Observational Study on Symptoms of the High Risk Group and Normal Group Used Postpartum Care Center during Six Weeks after Childbirth in Korean Medicine Hospital (고위험산모와 일반산모의 산후 6주간 증상에 대한 전향적 관찰 연구 - 일개 한방병원 산후조리원을 이용한 산모를 중심으로)

  • Jung, Jong-Kwan;Jeong, Seo-Yoon;Kim, An-Na;Jang, Hyun-Chul;Kim, Pyung-Wha;Lee, Eun-Hee
    • The Journal of Korean Obstetrics and Gynecology
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    • v.32 no.4
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    • pp.116-131
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    • 2019
  • Objectives: The aim of this study was to observe the changes of women's postpartum symptoms, the quality of life and depression scale over the first six weeks after childbirth. Methods: Twenty seven mothers who received Korean medical treatment in the outpatient department treatment (from September 27th, 2017 to January 5th, 2018) were evaluated for Verbal numerical rating scale (VNRS), edema index, EuroQol Visual Analogue Scale (EQ-VAS), and Edinburgh Postnatal Depression Scale (EPDS). Results: There were 17 high risk participants (63.0%) and 10 normal participants (37.0%). The VNRS of edema is the highest in the first week, and the VNRS of joint pain is the highest from the second week to the sixth week in all patients. The Extra Cellular Water/Total Body Water (ECW/TBW) of high risk group significantly decreased from $0.403{\pm}0.011$ to $0.387{\pm}0.006$(p<0.05) in the first 2 weeks. The ECW/TBW of normal group significantly decreased from $0.393{\pm}0.070$ to $0.383{\pm}0.011$ (p<0.05) in the first 2 weeks. The EQ-VAS of high risk group increased from $64.12{\pm}13.941$ to $69.35{\pm}18.155$ (p<0.05) in the first 2 weeks. But this difference was not significant statistically (p=0.234). The EQ-VAS of normal group significantly increased from $62.50{\pm}21.763$ to $74.00{\pm}9.661$ (p<0.05) in the first 2 weeks. The difference of EPDS was not statistically significant between the first week and the sixth week in every participants. Conclusions: VNRS was the highest in edema in the first week, joint pain was the highest from the second week to six week. The edema index of high risk groups was higher than that of the normal group in the first week (p<0.05). The EQ-VAS of normal group significantly increased (p<0.05) in the first 2 weeks but high risk group didn't. In the EPDS, the ratio of nine or more points of high risk group was more than twice than normal group in the first 2 weeks.

Risk Assessment of Smoke Generated During Combustion for Some Wood (일부 목재의 연소 시 발생되는 연기의 위험성 평가)

  • Chung, Yeong-Jin;Jin, Eui
    • Applied Chemistry for Engineering
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    • v.33 no.4
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    • pp.373-380
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    • 2022
  • In this study, Chung's equations 1, 2, and 3 were extended to standardize smoke safety rating evaluation in case of fire, and Chung's equations-V, smoke performance index-V, and smoke growth index-V were calculated. Five types of wood were selected and their smoke indices were measured using the cone calorimeter method according to ISO 5660-1. The smoke risk was graded by the smoke risk index-VI according to Chung's equation-VI. Smoke risk index-VI increased in the order of PMMA (1) ≈ maple (1.01) < ash (1.57) < needle fir (4.98) < paulownia (46.15) < western red cedar (106.26). It was predicted that maple and ash had the lowest smoke risk, and paulownia and western red cedar had the highest. The five samples' CO mean production rate (COPmean) was 0.0009~0.0024 g/s, indicating that these woods were incompletely burned than the polymethyl methacrylate (PMMA) reference material. Regarding the smoke properties of the chosen woods, the smoke performance index-V (SPI-V) increased as the bulk density increased, and the smoke risk index-VI (SRI-VI) decreased.

Poststroke Depression : A Review of the Latest Oriental Medicine Articles (뇌졸중 후 우울증 : 한방 치료에 대한 국내외 최신 문헌 고찰)

  • Lee, Je-Won;Lee, Bo-Mae-Na;Jang, Woo-Seok;Hwang, Ha-Yeon;Baek, Kyung-Min
    • The Journal of Internal Korean Medicine
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    • v.33 no.4
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    • pp.448-464
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    • 2012
  • Objectives : This study reviews the latest articles in Korea and other countries that studied oriental medicine treatment on poststroke depression. Methods : Korean articles were retrieved from the 9 major Korean web article search engines. Foreign articles were retrieved from PubMed. Article published date was from 2000 up to September 2012. There were no restrictions on the types of publication, but articles not available in full text were excluded. The methodological quality was assessed according to Cochrane's assessment of risk of bias and Newcastle-Ottawa quality assessment scale. Results : Twenty-two articles were included in this study. Eleven articles were published in Korea, the rest were published in China. Nine articles were randomized controlled trials (RCT), one article was a non-randomized study (NRS), four articles were case reports, three articles were cross-sectional studies, two articles were comparative studies. In RCT articles, risk of selection bias and performance bias were generally high, risk of detection bias was unclear. The NRS article took four stars in Newcastle-Ottawa quality assessment. Comparison Hamilton rating scale for depression score between oriental medicine treated group and western medicine treated group revealed that there was no remarkable difference in mean score changes after treatment on PSD. Conclusions : The results of this study suggest that oriental medicine treatment is as effective as western medicine treatment for PSD. In the future, more rigorous oriental medicine treatment studies should be conducted.

A Study on Classification of Disaster Risk Rating for Forest Road Using AHP Methodology (AHP기법을 활용한 임도의 재해위험 등급 구분에 관한 연구)

  • Bang, Hong-Seok;Kweon, Hyeong-Keun;Lee, Joon-Woo;Kim, Myeong-Jun
    • Journal of Korean Society of Forest Science
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    • v.103 no.2
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    • pp.258-263
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    • 2014
  • The purpose of this study is to provide basic data for forest roads management by using AHP methodology to group the grade of disaster risk. In addition to this, a field study was performed at 114 targeted points on forest roads where there are high risks of disaster occurrence. The results of the field survey and the analysis of AHP were compared to provide the degree of disaster risks. It shows that the drainage facilities occupied the highest weighted value. Meanwhile, based on AHP analysis data, evaluation chart was created by providing evaluation criteria and evaluation score to each evaluation items. As a result of applying the evaluation chart to the field survey data, the highest score was 78.8 and the lowest score was 42.7 with the mean score of 61.8. Finally, through the experts' consultation based on calculated scores, this study proposed four different groups of disaster risk on forest roads.

The Risk Rating System for Noise-induced Hearing Loss in Korean Manufacturing Sites Based on the 2009 Survey on Work Environments

  • Kim, Young-Sun;Cho, Youn-Ho;Kwon, Oh-Jun;Choi, Seong-Weon;Rhee, Kyung-Yong
    • Safety and Health at Work
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    • v.2 no.4
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    • pp.336-347
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    • 2011
  • Objectives: In Korea, an average of 258 workers claim compensation for their noise-induced hearing loss (NIHL) on an annual basis. Indeed, hearing disorder ranks first in the number of diagnoses made by occupational medical check-ups. Against this backdrop, this study analyzed the impact of 19 types of noise-generating machines and equipment on the sound pressure levels in workplaces and NIHL occurrence based on a 2009 national survey on work environments. Methods: Through this analysis, a series of statistical models were built to determine posterior probabilities for each worksite with an aim to present risk ratings for noise levels at work. Results: It was found that air compressors and grinding machines came in first and second, respectively in the number of installed noise-generating machines and equipment. However, there was no direct relationship between workplace noise and NIHL among workers since noise-control equipment and protective gear had been in place. By building a logistic regression model and neural network, statistical models were set to identify the influence of the noise-generating machines and equipment on workplace noise levels and NIHL occurrence. Conclusion: This study offered NIHL prevention measures which are fit for the worksites in each risk grade.

An investigation of the relationship between cutaneous allodynia and kinesiophobia, gastrointestinal system symptom severity, physical activity and disability in individuals with migraine

  • Hafize Altay;Seyda Toprak Celenay
    • The Korean Journal of Pain
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    • v.36 no.1
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    • pp.137-246
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    • 2023
  • Background: To investigate the relationship between cutaneous allodynia (CA) and kinesiophobia, gastrointestinal system (GIS) symptom severity, physical activity, and disability, and to determine whether CA, pain, and disability were influencing factors for kinesiophobia, GIS symptoms, and physical activity in individuals with migraine. Methods: The study included 144 individuals with migraine. CA, kinesiophobia, GIS symptoms, physical activity level, and migraine-related disability were evaluated with the Allodynia Symptom Checklist, the Tampa Kinesiophobia Scale (TKS), the Gastrointestinal Symptom Rating Scale (GSRS), the International Physical Activity Questionnaire-7, and the Migraine Disability Assessment Scale (MIDAS), respectively. Results: The CA severity was only associated with TKS (r = 0.515; P < 0.001), GSRS-total (r = 0.336; P < 0.001), GSRS-abdominal pain (r = 0.323; P < 0.001), GSRS-indigestion (r = 0.257; P = 0.002), GSRS-constipation (r = 0.371; P < 0.001), and MIDAS scores (r = 0.178; P = 0.033). Attack frequency (P = 0.015), attack duration (P = 0.035) and presence of CA (P < 0.001) were risk factors for kinesiophobia. Attack frequency (P = 0.027) and presence of CA (P = 0.004) were risk factors for GIS symptoms. Conclusions: There was a relationship between the CA and kinesiophobia, GIS symptoms, and disability. CA and attack frequency were found to be risk factors for kinesiophobia and GIS symptoms. Migraine patients with CA should be assessed in terms of kinesiophobia, GIS, and disability. Lifestyle changes such as exercise and dietary changes and/or pharmacological treatment options for CA may increase success in migraine management.