• Journal of IKEEE
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• v.13 no.2
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• pp.140-149
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• 2009

Traffic anomaly detection is one of important technology that should be considered in network security and administration. In this paper, we propose an abnormal traffic detection mechanism that includes traffic monitoring and traffic analysis. We develop analytical passive monitoring system called WISE-Mon which can inspect traffic behavior. We establish a criterion by analyzing the characteristics of a traffic training set. To detect abnormal traffic, we derive a hyperplane by using Fisher linear discriminant and chi-square distribution as well as the analyzed characteristics of traffic. Our mechanism can support reliable results for traffic anomaly detection and is compatible to real-time detection. In addition, since the trend of traffic can be changed as time passes, the hyperplane has to be updated periodically to reflect the changes. Accordingly, we consider the self-learning algorithm which reflects the trend of the traffic and so enables to increase the pliability of detection probability. Numerical results are presented to validate the accuracy of proposed mechanism. It shows that the proposed mechanism is reliable and relevant for traffic anomaly detection.

• Journal of Convergence for Information Technology
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• v.9 no.8
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• pp.268-273
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• 2019

The study was to find out whether the more difficult each activities of daily living(ADLs) is, the more high subjective health status, or health insecurity, is among those in their 65 or older in Seoul and Gyeonggi Province. The subjects were asked up to 1 to 5 points for subjective health status and ADLs. And according to the performance level of each activities of daily living, the order trend was analyzed in four groups (very difficult, difficult, easy, and very easy) by Jonckheere-Terpstra. Order trends were also compared using a linear regression line. Depending on the degree of difficulty in "using toilet," "bathing" and "shopping," the insecurities in subjective health status showed a corresponding order differences. It has been shown that the slope of "using toilet" on a linear regression line is the largest. The more difficult it was to "use toilet," "bathing" and "shopping," the higher the score of health insecurity was.

• Ocean and Polar Research
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• v.40 no.1
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• pp.1-13
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• 2018

Previous studies have indicated a great regional difference in Sea Level Rise (SLR) in the Pacific and it has been suggested that this is linked to climate variability over the past two decades. In this study, we seek to identify the possible linkage between regional sea level and Pacific climate variability from altimetry-based sea level data (1993-2012) and further investigate how the Pacific sea level has changed spatially and temporally over the past 60 years from long-term sea level reconstruction data (1953-2008). Based on the same method as Zhang and Church (2012), the Inter-annual Climate Index (ICI) associated with the El $Ni{\tilde{n}}o-Southern$ Oscillation (ENSO) and the Decadal Climate Index (DCI) associated with Pacific Decadal Oscillation (PDO) are defined and then the multiple variable linear regression is used to analyze quantitatively the impact of inter-annual and decadal climate variability on the regional sea levels in the Pacific. During the altimeter period, the ICI that represents ENSO influence on inter-annual time scales strongly impacts in a striking east-west "see-saw mode" on sea levels across the tropical Pacific. On the other hand, the decadal sea level pattern that is linked to the DCI has a broad meridional structure that is roughly symmetric in the equator with its North Pacific expression being similar to the PDO, which largely contributes to a positive SLR trend in the western Pacific and a negative trend in the eastern Pacific over the two most recent decades. Using long-term sea level reconstruction data, we found that the Pacific sea levels have fluctuated in the past over inter-annual and decadal time scales and that strong regional differences are presented. Of particular interest is that the SLR reveals a decadal shift and presents an opposite trend before and after the mid-1980s; i.e., a declining (rising) trend in the western (eastern) Pacific before the mid-1980s, followed by a rising (declining) trend from the mid-1980s onward in the western (eastern) Pacific. This result indicates that the recent SLR patterns revealed from the altimeters have been persistent at least since the mid-1980s.

• Journal of Korea Water Resources Association
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• v.43 no.4
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• pp.409-419
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• 2010

In this study, for the purpose of analyzing the characteristics of Korean hydrologic weather parameters, 9 hydrologic weather parameters data such as annual precipitation, annual rainy days, annual average relative humidity, annual average temperature, annual duration of sunshine, annual evaporation, annual duration of precipitation, annual snowy days and annual new snowy days are collected from 63 domestic meteorological stations that has the hydrologic weather parameters records more than 30 years. And the basic characteristics of hydrologic weather parameters through basic statistics, moving average and linear regression analysis are perceived. Also trend using the statistical methods like Hotelling-Pabst test and Mann-Kendall test about hydrologic weather parameters is analyzed. Through results of basic analysis, moving average and linear regression analysis it is shown that precipitation is concentrated in summer and deviation of precipitation for each season showed significant difference in accordance with Korean climate characteristics, besides the increase in annual precipitation and annual average temperature, annual average relative humidity and annual duration of sunshine reduction and annual rainy days is said to increase or decrease. The results of statistical analysis of trend are summarized as trend commonly appeared in annual average relative humidity and annual average temperature. and annual precipitation, annual rainy days and annual duration of sunshine showed different results according to area.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.5
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• pp.586-590
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• 2010

In this paper we formally define the linear detrending subsequence matching and propose its efficient index-based solution. To this end, we first present the notion of LD-windows. We eliminate the linear trend from a subsequence rather than each window itself and obtain LD-windows by dividing the subsequence into windows. Using the LD-windows we present a lower bounding theorem of the index-based solution and formally prove its correctness. Based on this lower bounding theorem, we then propose the index building and subsequence matching algorithms, respectively. Finally, we show the superiority of our index- based solution through experiments.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.2
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• pp.228-236
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• 2021

In order to understand the underwater noise source factor of the linear pump type forced ejection system, a reduced-model compressed water experiment device was developed. The reduced-model compressed water experiment device consists of a reverberation tank, a linear pump type forced ejection device, and an underwater vehicle. The underwater noise source was selected from the hydraulic ram moving speed, the hydraulic ram/piston pipe spacing, the ejection pipe inlet/water ram area ratio, and the number of water ram inlets. The underwater vehicle was ejected into the reverberation tank by the device. The source level was derived from the measured sound pressure. The source level tends to increase as the hydraulic ram/piston tube spacing and the hydraulic ram moving speed increase. The source level tended to increase as the area ratio was increased, but the level was weak. The number of water ram inlet did not affect the source level.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.3
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• pp.2067-2070
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• 2013

Background/Aim: Stomach cancer is the second most common cause of death from all malignant tumors in the world (third in men, fifth in women), with a strong decreasing trend in most developed countries. The aim of this descriptive epidemiological study was to analyze mortality of stomach cancer in Serbia, excluding the Province of Kosovo, in the 1991-2009 period. Materials and Methods: In data analysis, we used mortality rates which were standardized directly using those of the world population as a standard. In order to analyze the mortality trend from stomach cancer, linear trend and regression analysis were used. Confidence intervals (CIs) for the average age-adjusted and age-specific mortality rates were assessed with 95% level of probability. Mortality data were derived from the data file of the Statistical Office of the Republic of Serbia. Results: During the 1991-2009 period, a significant downward trend in mortality of stomach cancer was recorded in Serbia (y=9.78 - 0.13x, p=0.000; average annual percent change was -6.3 (95%CI, -7.8 to - 4.8). During the same period, a significant decrease in mortality trend was found both in male (y=14.13 - 0.20x; p=0.000; % change was -7.7 (95%CI, -10.9 to -4.5) and female populations (y=6.27 - 0.08x; p=0.000; % change was - 4.4 (95%CI, -5.3 to -3.6). Conclusion: Decreasing trends in mortality from stomach cancer in Serbia are similar to those in most developed countries.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3499-3503
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• 2015

Background: Cancer has become an epidemic disease. Nearly ten million new cancer cases are diagnosed annually in the world and out of these about half are from the developing world. To appropriately plan for treatment, management and prevention of the disease, it becomes necessary to study the trends about morbidity caused by cancers. Materials and Methods: Data for patients diagnosed with any form of gastrointestinal (GI) cancers was extracted from records maintained in the outpatient department registers of the Oncology Department of Government Medical College and Hospital in Chandigarh from 1999 to 2012. Trends were analysed for different categories of GI cancers for the period of 12 years. Results: In present study GI cancers accounted for 23 % of all registered cases (n-9603) of carcinomas. Males predominated for all GI cancers except in the gall bladder. Gastrointestinal cancers as a proportion of total cancers increased from 21% in 1999 to 25.9% in 2012 with a significant increasing trend in our series (${\chi}^2$ for linear trend=9.36, p<0.003). Cancers of the tonsil, oral cavity and pharynx taken together showed an increasing trend over the years (${\chi}^2$ for trend=55.2, p<0.001) whereas cancers of the lower GI (${\chi}^2=19.6$, p<0.0001) and gall bladder (${\chi}^2=19.5$, p<0.0001) showed a declining trend in our series. Conclusions: GI cancers form a significant proportion of all cancers reporting to our data. In depth studies to ascertain the reasons for the changing trends are required to design intervention programs. Further information is necessary from cancer registries and from the hospital records of oncology departments.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.2
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• pp.26-35
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• 2006

Design parameters of manned and unmanned rotorcrafts have been investigated to construct a design database and to derive trend curves. Design parameters of 78 manned rotorcrafts and 33 unmanned rotorcrafts have been collected and analyzed using linear regression method. Six kinds of trend curves equations are derived. Most of trend curves derived are relatively meaningful according to the calculated correlation and determination coefficients. The comparisons between manned and unmanned rotorcraft characteristics are performed. It has been drawn according to the comparisons that unmanned rotorcraft has smaller main rotor diameter and maximum take-off weight, bigger tail rotor size and similar level of empty weight fraction than manned rotorcraft.

• Journal of Korean Academy of Nursing
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• v.44 no.6
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• pp.743-750
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• 2014

Purpose: The objective of this study was to provide a trend analysis of the prevalence of diabetes relative to the socioeconomic, lifestyle, and physiologic risk factors among Korean adults aged over 30 years for a 10-year period using data from the Korean National Health and Nutrition Examination Survey. Methods: Prevalence difference and the slope index of inequality were calculated for each risk factors using binomial regression by considering the repeated cross-sectional features of the data. The prevalence ratio and the relative index of inequality were calculated using log-binomial regression. Linear trend tests were performed using SAS 9.2. Results: Crude prevalence of diabetes increased over the 10-year period, and was higher for men than for women. It was very high for adults 60 years or over, consistently increasing over time. The prevalence among unemployed men, women with higher level of stress, women with hypertension, and adults with serum triglyceride levels over 135 mg/dL increased over the 10-year period in comparison with the respective control group. Conclusion: Considering the rapid economic development and associated lifestyle changes in Korea, action should be taken to control the prevalence of diabetes by both preventing and consistently monitoring these identified risk factors using a public-health approach.