• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.6
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• pp.599-607
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• 2004

In this paper, using phase locked loop(PLL) synthesizer, we introduce a novel but simple and low cost frequency modulation(FM) circuit of a flat peak frequency deviation fur modulation signal whose frequency covers from outside to inside of the loop-bandwidth of PLL. The FM circuit was basically designed to compensate an amount of feedback of the loop filter in PLL. The circuit also includes the capability of the adjustment of peak frequency deviation and of blocking the intereference with the loop filter. The designed circuit was successfully implemented and showed the flat frequency deviation as expected in the design. In addition, the novel measurement method of the wideband FM modulation index is suggested verified With the suggest measurement, it can be successfully shown the designed circuit has the expected frequency deviation.

• Journal of Korean Academy of Nursing
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• v.34 no.4
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• pp.636-645
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• 2004

Purpose. A natural disaster negatively affects children's emotional and behavioral adjustment. The purpose of this paper was to examine the prevalence, symptoms, and correlates of PTSD after the occurrence of Typhoon Rusa. Method. 261 elementary school children living in Kimcheon, which was a devastated rural area in South Korea by Typhoon Rusa, were selected. Data were collected 4 months after the disaster using the PTSD Reaction Index categories recommended by Frederick, severity of PTSD. Results. 12.3% of the children had either moderate or severe PTSD symptoms; 22.7% reported mild symptoms; and the remaining 65% had sub-clinical symptoms of PTSD. The most frequent symptom was recurrenct fear(67.0%). 13% to 17.2% of children exhibited difficulty in concentration, sleep disturbance, and guilt feeling. The regression model of severity of PTSD was composed of the level of exposure to traumatic experiences, grade in school, gender, negative coping style, and social support, and explained 34.3% for PTSD symptoms. Exposure to traumatic experiences was the strongest factor of all predictors. Conclusion. Emotional support from friends and coping style were correlated with PTSD severity. School-based interventions that emphasizes coping with disaster related problems and problem-solving may prove to be useful, and may aid in building close and supportive ties with teachers, classmates, and friends.

• Clinical and Experimental Pediatrics
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• v.62 no.11
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• pp.416-421
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• 2019

Background: The seropositivity rate of hepatitis B surface antigen (anti-HBs) antibodies is known to be ≥95% after hepatitis B virus vaccination during infancy. However, a low level or absence of anti-HBs in healthy children is discovered in many cases. Recent studies in adults reported that a reduced anti-HBs production rate is related to obesity. Purpose: To investigate whether body mass index (BMI) affects anti-HBs levels in healthy children following 3 serial dose vaccinations in infancy. Methods: We recruited 1,200 healthy volunteers aged 3, 5, 7, or 10 years from 4-day care centers and 4 elementary schools. All subjects completed a questionnaire including body weight, height, and vaccine type received. Levels of serum hepatitis B surface antigen (HBsAg) and anti-HBs in all subjects were analyzed using electrochemiluminescence immunoassay. The standardized scores (z score) for each sex and age were obtained using the lambda-mu-sigma method in the 2017 Korean National Growth Charts for children and adolescents. Results: Our subjects (n=1,200) comprised 750 males (62.5%) and 450 females (37.5%). The overall anti-HBs seropositivity rate was 57.9% (695 of 1,200). We identified significant differences in mean BMI values between seronegative and seropositive groups (17.45 vs. 16.62, respectively; P<0.001). The anti-HBs titer was significantly decreased as the BMI z score increased adjusting for age and sex (B=-15.725; standard error=5.494; P=0.004). The probability of anti-HBs seropositivity based on BMI z score was decreased to an OR of 0.820 after the control for confounding variables (95% confidence interval, 0.728-0.923; P=0.001). Conclusion: There was a significant association between anti-HBs titer and BMI z score after adjustment for age and sex. Our results indicate that BMI is a potential factor affecting anti-HBs titer in healthy children.

• Journal of Korea Water Resources Association
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• v.35 no.6
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• pp.685-692
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• 2002

It is very useful to estimate easily the various characteristics of streams and to manage objectively streams, as the order or grade among streams is determined by the natural characteristics and the degree of human utilization. With obtainable various statistics data and expert examination, we proposed the measurable evaluation index of "stream weight" considering the natural characteristics of streams, the utilization degree of streams and the social conditions of the regions crossed streams. The each stream weight is calculated as follows. Firstly, select the various factors which influence to streams in AHP. Secondly, determine the each weight of factors by the result of expert examination. Finally, sum up after multiplying the normalized factors by these two values. The stream weight can be used such divisions as the recognization of relative weight between streams, the determination of the stream management direction in the near future, the enhancement of the efficiency of stream management through the adjustment of the present stream grade and the determination of the management method concerned the stream weight as well.t as well.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.1
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• pp.77-86
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• 2023

PURPOSE: This study developed an experimental algorithm, which is similar or identical to semantic linking for KCF codes, even if it converted existing semantic code linking methods to morphological code extraction methods. The purpose of this study was to verify the applicability of the system. METHODS: An experimental algorithm was developed as a morphological extraction method using code-specific words in the KCF code descriptions. The algorithm was designed in five stages that extracted KCF code using natural language paragraphs. For verification, 80 clinical natural language experimental cases were defined. Data acquisition for the study was conducted with the deliberation and approval of the bioethics committee of the relevant institution. Each case was linked by experts and was extracted through the System. The linking accuracy index model was used to compare the KCF code linking by experts with those extracted from the system. RESULTS: The accuracy was checked using the linking accuracy index model for each case. The analysis was divided into five sections using the accuracy range. The section with less than 25% was compared; the first experimental accuracy was 61.24%. In the second, the accuracy was 42.50%. The accuracy was improved to 30.59% in the section by only a weight adjustment. The accuracy can be improved by adjusting several independent variables applied to the system. CONCLUSION: This paper suggested and verified a way to easily extract and utilize KCF codes even if they are not experts. KCF requires the system for utilization, and additional study will be needed.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.7
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• pp.339-349
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• 2001

This paper suggests an optimal identification method for complex and nonlinear system modeling that is based on Fuzzy-Neural Networks(FNN). The proposed Hybrid Identification Algorithm is based on Yamakawa's FNN and uses the simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. In this paper, the FNN modeling implements parameter identification using HCM algorithm and hybrid structure combined with two types of optimization theories for nonlinear systems. We use a HCM(Hard C-Means) clustering algorithm to find initial apexes of membership function. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are adjusted using hybrid algorithm. The proposed hybrid identification algorithm is carried out using both a genetic algorithm and the improved complex method. Also, an aggregated objective function(performance index) with weighting factor is introduced to achieve a sound balance between approximation and generalization abilities of the model. According to the selection and adjustment of a weighting factor of an aggregate objective function which depends on the number of data and a certain degree of nonlinearity(distribution of I/O data), we show that it is available and effective to design an optimal FNN model structure with mutual balance and dependency between approximation and generalization abilities. To evaluate the performance of the proposed model, we use the time series data for gas furnace, the data of sewage treatment process and traffic route choice process.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.4
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• pp.343-350
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• 2000

In this paper, we propose the Multi-FPNN(Fuzzy Polynomial Neural Networks) model based on FNN and PNN(Polyomial Neural Networks) for optimal system identifacation. Here FNN structure is designed using fuzzy input space divided by each separated input variable, and urilized both in order to get better output performace. Each node of PNN structure based on GMDH(Group Method of Data handing) method uses two types of high-order polynomials such as linearane and quadratic, and the input of that node uses three kinds of multi-variable inputs such as linear and quadratic, and the input of that node and Genetic Algorithms(GAs) to identify both the structure and the prepocessing of parameters of a Multi-FPNN model. Here, HCM clustering method, which is carried out for data preproessing of process system, is utilized to determine the structure method, which is carried out for data preprocessing of process system, is utilized to determance index with a weighting factor is used to according to the divisions of input-output space. A aggregate performance inddex with a wegihting factor is used to achieve a sound balance between approximation and generalization abilities of the model. According to the selection and adjustment of a weighting factor of this aggregate abjective function which it is acailable and effective to design to design and optimal Multi-FPNN model. The study is illustrated with the aid of two representative numerical examples and the aggregate performance index related to the approximation and generalization abilities of the model is evaluated and discussed.

• Journal of Korea Water Resources Association
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• v.49 no.12
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• pp.1027-1034
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• 2016

One of the most important purpose of multi-purpose reservoir is storing a large amount of water for utilization in a dry season. However, multi-purpose reservoirs that were constructed according to the limited hydrologic information available at the time of construction may encounter problems such as decreased water inflow due to climate change and an inability to cope with a water shortage. To solve these problems, in 2015, the Ministry of Land, Infrastructure and Transport suggested a revised water supply standard in case of water shortage for reservoirs. However, the revised standard has not been sufficiently discussed to determine its effectiveness. In addition, multi-purpose reservoirs in South Korea have secured and stored water for emergencies, but there is currently no way to utilize the stored water. Determining how to utilize the stored water effectively may be a useful method for preparing drought. Therefore, this article discusses the revised water supply standard as it relates to a water shortage in reservoirs and a method of utilizing the water stored for emergencies in multi-purpose reservoirs. The options for utilizing the water storage were evaluated using a water shortage safety degree index, and the results showed that the options may slightly and limitedly increase the water supply capacity. However, the evaluation also showed that a complex application of two options may overcome the exisiting problem and to supply water more effectively.

• Journal of the Korean Institute of Intelligent Systems
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• v.10 no.5
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• pp.487-496
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• 2000

In this paper, the Multi-FNN(Fuzzy-Neural Networks) model is identified and optimized using HCM(Hard C-Means) clustering method and genetic algorithms. The proposed Multi-FNN is based on Yamakawa's FNN and uses simplified inference as fuzzy inference method and error back propagation algorithm as learning rules. We use a HCM clustering and Genetic Algorithms(GAs) to identify both the structure and the parameters of a Multi-FNN model. Here, HCM clustering method, which is carried out for the process data preprocessing of system modeling, is utilized to determine the structure of Multi-FNN according to the divisions of input-output space using I/O process data. Also, the parameters of Multi-FNN model such as apexes of membership function, learning rates and momentum coefficients are adjusted using genetic algorithms. A aggregate performance index with a weighting factor is used to achieve a sound balance between approximation and generalization abilities of the model. The aggregate performance index stands for an aggregate objective function with a weighting factor to consider a mutual balance and dependency between approximation and predictive abilities. According to the selection and adjustment of a weighting factor of this aggregate abjective function which depends on the number of data and a certain degree of nonlinearity, we show that it is available and effective to design an optimal Multi-FNN model. To evaluate the performance of the proposed model, we use the time series data for gas furnace and the numerical data of nonlinear function.

• Korean Journal of Community Nutrition
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• v.12 no.3
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• pp.272-283
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• 2007

This study was performed to delineate the relationship between lifestyle and nutritional risk factors associated with hypertension in representative middle-aged Korean population. Hypertension in this study is defined as hypertensive ($SBP{\geq}140mmHg\;or\;DBP{\geq}90mmHg$) adults without recognition of a disease state before a health exam. With data from the 1998 and 2001 National Health and Nutritional Survey, nutrient intakes of 6,112 adults, 40-64 years of age were calculated using food composition database and matched with health examination records by individual ID. After excluding those with extreme intake values, the number of final subjects included in the analysis was 5,200 (male 2,458, female 2,742). Using logistic regression method, socio-demographic data, lifestyle factors, and nutrient intakes were analyzed. Risky factors for hypertension revealed in this study were age, sex, BMI over 23, waist circumference, alcohol intake of more than 16g (male) or 8g (female). Regarding nutrient intakes, the intakes of highest quartile for energy (${\geq}2363.0kcal$) and protein (${\geq}90.2g$) were significantly associated with higher risk of hypertension after adjusting for age, sex, and other socio-demographic factors (OR=1.312(1.046-1.711), OR=1.488(1.194-1.854), respectively)). Although high intakes of sodium (${\geq}6604.0mg$) and phosphorus seemed to be risk factors of hypertension also before energy adjustment (OR=1.278(1.034-1.581), OR=1.280(1.024-1.600), respectively), only high intakes of energy and protein remained significant after adjustment. This study revealed that modifying risky lifestyles and dietary patterns, especially high energy intake, high protein intake, and high alcohol drinking, in middle-aged Korean adults could result in a prevalence decrease and/or prevention of hypertension.