• Journal of Preventive Medicine and Public Health
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• v.47 no.3
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• pp.158-168
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• 2014

Objectives: To identify and evaluate the trend of meal-skipping rates among Korean adolescents with their contributing causes and the influence of household income level on meal skipping. Methods: Using 2008, 2010, and 2012 data from the Korea Youth Risk Behavior Web-based Survey of 222 662 students, a cross-sectional study with subgroup analysis was performed. We calculated odds ratios for skipping each meal 5 or more times in a week by household socio-economic status using a multiple logistic regression model. The secular change in the meal-skipping rates by the students' family affluence scale was analyzed by comparing the meal-skipping students within each subgroup and odds ratios for the same event over time. Results: Through 2008 to 2012, most of the meal-skipping rates generally showed a continuous increase or were almost unchanged in both sexes, except for breakfast skipping in several subgroups. Students in low-income households not living with both parents had the highest meal-skipping rates and odds ratios for frequent meal skipping. In a time-series subgroup analysis, the overall odds ratios for the same event increased during 2008 to 2012, with a slight reduction in the gap between low and higher income levels with regard to meal skipping during 2010 to 2012. Conclusions: Household socio-economic status and several other factors had a significant influence on Korean adolescent meal-skipping rates. Although the gap in eating behavior associated with household socio-economic differences is currently decreasing, further study and appropriate interventions are needed.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.10
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• pp.6035-6040
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• 2013

Background: Cancer is a complex disease caused by multiple factors, both genetic and environmental. It is a major health concern worldwide, in the Middle East and in Jordan specifically and the fourth most common killer in the Middle East. Hypothesis: The relative genetic homogeneity of the Circassian and Chechan populations in Jordan results in incidences of cancer that differ from the general Jordanian population, who are mostly Arabs. Materials and Methods: National Cancer Registry data were obtained for the years 1996-2005 The Chechen and Circassian cancer cases were identified and cancer registry data were divided into three populations. Crude rates were calculated based on the number of cancer cases and estimated populations. Results: Breast cancer is the most common cancer type constituting about one third of female cancers in all three populations. Higher crude rates are observed in the Circassian and Chechen populations than in the Arab Jordanian population. The rate ratios (95%CI) in Circassians and Chechens with respect to the Arab Jordanian population are 2.1 (1.48, 2.72) and 1.81 (1.16, 2.85), respectively. Lung cancer is the most common cancer in male Arab Jordanians and Chechens with crude rates of 4.2 and 8.0 per 100,000 respectively. The male to female ratio in these two populations in respective order are 5:1 and 7:1. The lung cancer crude rate in Circassians is 6.5 per 100,000 with a male to female ratio of only 1.6:1. The colorectal cancer crude rates in Arab Jordanians and Chechens are similar at 6.2 and 6.0 per 100,000, respectively, while that in Circassians is twice as high. Conclusions: Considerable ethnic variation exists for cancer incidence rates in Jordan. The included inbred and selected populations offer an ideal situation for investigating genetic factors involved in various cancer types.

• Journal of Preventive Medicine and Public Health
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• v.25 no.1 s.37
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• pp.64-72
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• 1992

To provide the information necessary for the insurance medicine management plan, price discount rates among the insurance medicines were studied. A total of 2,107 items of insurance medicine of which prices were discounted via governmental inspections of real transactional process of insurance medicine were analysed. The conclusions are as follows; 1. Among the variables relevant to the characteristics of manufacturers, price discount rates of insurance medicines were statistically significant with production rankings of manufacturers, incorporation year, existence of investments by foreign corporation, existence of a research institute, and enrollment in the exchange. And among the variables relevant to the properties of medicines, the number of enrolled items which have the same components, classification, the date of new enrollment, the sales of items, and the number of raw materials in the items were statistically significant. 2. Stepwise multiple regression was done to identify the factors which affect the price discount rates of insurance medicines. The number of enrolled items which have the same components, production rankings of manufactures, classification number (medicines for function of tissue cells), incorporation year(1940-1949), existence of investments by foreign corporations, classification number (anti-germ medicines), number of raw materials In the items, the sales of items, and medicines whose major objective is not treatment were significant variables and the $R^2$-value for these variables was 21.2%. Considering all of the above results, for management of insurance medicines, it seems important that the real transactional prices of insurance medicines should be identified systematically, focusing on the properties which affect the price discount rates of insurance medicines.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.5
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• pp.101-108
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• 2019

The domestic duck industry is the sixth-largest among the livestock industries. However, 34.3% of duck houses were the duck houses arbitrarily converted from plastic greenhouses. This type of duck house was difficult to properly manage internal air temperature and humidity environment. Humidity environment inside duck houses is an important factor that directly affects the productivity and disease occurrence of the duck. Although the humidity environments of litters (bedding materials) affect directly the inside environment of duck houses, there are only few studies related to humidity environment of litters. In this study, evaporation rates from litters were evaluated according to air temperature, relative humidity, water contents of litters, and wind speed. The experimental chamber was made to measure evaporation rates from litters. Temperature and humidity controlled chamber was utilized during the conduct of the laboratory experiments. Using the measured data, a multi linear regression analysis was carried out to derive the calculation formula of evaporation rates from litters. In order to improve the accuracy of the multi linear regression model, the partial vapor pressure directly related to evaporation was also considered. Variance inflation factors of air temperature, relative humidity, partial vapor pressure, water contents of litters, and wind speed were calculated to identify multicollinearity problem. The Multiple $R^2$ and adjusted-$R^2$ of regression model were calculated at 0.76 and 0.71, respectively. Therefore, the regression models were developed in this study can be used to estimate evaporation rates from the litter of duck houses.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2333-2336
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• 2013

Background: The aim of this paper was to present the incidence rates of leukemia and multiple myeloma (MM) in Golestan province located in northeastern Iran during 2004-2009. Materials and Methods: This was a descriptive cross-sectional study. Data on newly diagnosed (incident) leukemia and MM cases were obtained from collected from Golestan population-based cancer registry. Data was entered into CanReg-4 software. Age standardized incidence rates (ASR) (per 100000 person-years) for leukemia and MM were calculated. Data on Golestan population was obtained from the data of Iranian national census in 2006. Results: Totally, 11036 new cancer cases were registered in GPRC from 2004-2009. Leukemia and MM accounted for 693 and 124 of cases, respectively. The mean age in patients with leukemia and MM was 43.8 and 62.4 years, respectively. The ASRs for leukemia among men and women were 10.4 and 7.8, respectively (p<0.001). The ASRs for MM were 2.1 and 2 in men and women, respectively (p=0.93). The rate of leukemia was significantly higher in rural areas (p=0.02) whereas the incidence of MM was higher in urban areas (p<0.001). Conclusions: Our results showed a high incidence rate of leukemia in Golestan province of Iran. The incidence of leukemia was significantly higher in males and residents of rural areas. High exposure to pesticides and other agricultural related products may be a possible explanation for epidemiological pattern of leukemia in this area. Determining and controlling important risk factors, especially environmental factors, of leukemia may lead to decrease in its burden in Golestan province of Iran.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.1A
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• pp.73-81
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• 2011

IEEE 802.11 PHY and MAC layer provide multiple channels and data rates. To improve the performance of IEEE 802.11 multi-radio ad hoc networks, it is required to utilize available channels and data rates efficiently. However, in IEEE 802.11 multi-rate networks, the rate anomaly (RA) problem occurs that the network performance is severely degraded as low-rate links affect high-rate links. Hence, in this paper, we propose a model-based rate separation (MRS) algorithm that uses multiple channels to separate different data rate links so that the RA problem is mitigated. MRS algorithm utilizes an existing throughput model that estimates the throughput of IEEE 802.11 single-hop networks to separate low-rate links and high-rate links. Through simulations, we demonstrate that the MRS algorithm shows improved network performance compared with existing algorithms in multi-radio ad hoc networks.

• Journal of the Korean Data and Information Science Society
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• v.26 no.4
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• pp.931-946
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• 2015

Many multiple life insurance products consider benefits that are contingent on the combined survival status of two lives. To value premiums of the insurance products accurately, we need to consider the impact of the survivorship of one life on another. To show a dependence relation between married couple, we calculate correlation coefficients by using married couples data from National Pension Service and the results show some positive dependence between them. Moreover, by analyzing the death after bereavement, we find a evidence that mortality rates increase after the death of a spouse and, in addition, that this phenomenon, the broken-heart syndrome, diminishes over time. The results of this study can support the method to calculate the premium of multiple life insurance reflecting more realistic joint mortality rates.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.4
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• pp.279-285
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• 2007

The objective of the research is two fold. The first is to design and propose a stable and robust learning control algorithm. The controller is CMAC Learning Controller which consists of a model-based controller, such as LQR or PID, as a reference control and a CMAC. The second objective is to implement a reference control and CMAC at two different sampling rates. Generally, a conventional controller is designed based on a mathematical plant model. However, increasing complexity of the plant and accuracy requirement on mathematical models nearly prohibits the application of the conventional controller design approach. To avoid inherent complexity and unavoidable uncertainty in modeling, biology mimetic methods have been developed. One of such attempts is Cerebellar Model Articulation Computer(CMAC) developed by Albus. CMAC has two main disadvantages. The first disadvantage of CMAC is increasing memory requirement with increasing number of input variables and with increasing accuracy demand. The memory needs can be solved with cheap memories due to recent development of new memory technology. The second disadvantage is a demand for processing powers which could be an obstacle especially when CMAC should be implemented in real-time. To overcome the disadvantages of CMAC, we propose CMAC learning controller with multiple sampling rates. With this approach a conventional controller which is a reference to CMAC at high enough sampling rate but CMAC runs at the processor's unoccupied time. To show efficiency of the proposed method, an inverted pendulum controller is designed and implemented. We also demonstrate it's possibility as an industrial control solution and robustness against a modeling uncertainty.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.5
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• pp.31-36
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• 2011

In this paper, Mel-Frequency Cepstral Coefficient (MFCC), Decorrelated Filter Bank (DFB), Octave-based Spectral Contrast (OSC), Zero-Crossing Rate (ZCR), and Spectral Contract/Roll-Off are combined as a set of multiple feature-vectors for the music genre classification system based on the Support Vector Machine (SVM) classifier. In the conventional system, feature vectors for the entire genre classes are normalized for the SVM model training and classification. However, in this paper, selected feature vectors that are compared based on the One-Against-One (OAO) SVM classifier are only used for normalization. Using OSC as a single feature-vector and the multiple feature-vectors, we obtain the genre classification rates of 60.8% and 77.4%, respectively, with the conventional normalization method. Using the proposed normalization method, we obtain the increased classification rates by 8.2% and 3.3% for OSC and the multiple feature-vectors, respectively.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.11
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• pp.6955-6959
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• 2013

The incidence of hepatocellular carcinoma (HCC) is relatively high in Southeast Asia. Globally, HCC has a high fatality rate and short survival. The objectives of this retrospective cohort study were to review the epidemiology and survival of HCC patients at a tertiary centre in north-east of Peninsular Malaysia. Subjects were adult HCC patients diagnosed by histopathology or radio-imaging. Secondary liver carcinoma was excluded. Kaplan Meier and multiple Cox proportional hazard survival analyses were used. Only 210 HCC cases from years 1987-2008, were included in the final analysis. The number of cases was increasing annually. The mean age was 55.0 (SD 13.9) years with male:female ratio of 3.7:1. Approximately 57.6% had positive hepatitis B virus, 2.4% hepatitis C virus, 20% liver cirrhosis and 8.1% chronic liver disease. Only 2.9% had family history and 9.0% had frequently consumed alcohol. Most patients presented with abdominal pain or discomfort and had hepatomegaly, 47.9% had an elevated ${\alpha}$-fetoprotein level of 800 IU/ml or more, 51.9% had multiple tumors and 44.8% involved multiple liver lobes. Approximately 63.3% were in stage 3 and 23.4% in stage 4, and 82.9% did not receive any treatment. The overall median survival time was 1.9 months (95% confidence interval (CI): 1.5, 2.3). The 1-month, 6-month, 1-year and 2-year survival rates were 71.8%, 23.3%, 13.0% and 7.3% respectively. Significant prognostic factors were Malay ethnicity [Adjusted hazard ratio (AHR) 1.6; 95%CI: 1.0, 2.5; p=0.030], no chemotherapy [AHR 1.7; 95%CI: 1.1, 2.5; p=0.017] and Child-Pugh class C [AHR 2.6; 95%CI: 1.4, 4.9; p=0.002]. HCC in our study affected a wide age range, mostly male, in advanced stage of disease, with no treatment and very low survival rates. Primary prevention should be advocated in view of late presentation and difficulty of treatment. Vaccination of hepatitis virus and avoidance of liver toxins are to be encouraged.