• Proceedings of the KSME Conference
• /
• 2003.11a
• /
• pp.320-325
• /
• 2003

Acoustic-Pressure Response of diluted hydrogen-air diffusion flames is investigated numerically by adopting a fully unsteady analysis of flame structures. In the low-pressure regime, the amplification index remains low and constant at low frequencies. As acoustic frequency increases, finite-rate chemistry is enhanced through a nonlinear accumulation of heat release rate, leading to a high amplification index. Finally, the flame responses decrease at high frequency due to the response lag of the transport zone. For a medium-pressure operation and low-frequency excitation, the amplification index is low and constant. It then decreases at moderate frequencies. As frequency increases further, the amplification index increases appreciably due to an intense accumulation effect.

• Journal of Korea Water Resources Association
• /
• v.45 no.4
• /
• pp.393-407
• /
• 2012

This study suggests the results of temporal and spatial variations for rainfall data in the Korean Peninsula. We got the index of the rainfall amount, frequency and extreme indices from 65 weather stations. The results could be easily understood by drawing the graph, and the Mann-Kendall trend analysis was also used to determine the tendency (up & downward/no trend) of rainfall and temperature where the trend could not be clear. Moreover, by using the FARD, frequency probability rainfalls could be calculated for 100 and 200 years and then compared each other value through the moment method, maximum likelihood method and probability weighted moments. The Average Rainfall Index (ARI) which is meant comprehensive rainfalls risk for the flood could be obtained from calculating an arithmetic mean of the RI for Amount (RIA), RI for Extreme (RIE), and RI for Frequency (RIF) and as well as the characteristics of rainfalls have been mainly classified into Amount, Extremes, and Frequency. As a result, these each Average Rainfall Indices could be increased respectively into 22.3%, 26.2%, and 5.1% for a recent decade. Since this study showed the recent climate change trend in detail, it will be useful data for the research of climate change adaptation.

• Journal of Environmental Impact Assessment
• /
• v.15 no.3
• /
• pp.207-215
• /
• 2006

The purpose of this paper is to analyze the spatial distribution and change of the frequency of Yellow Sand days and to examine their relationship with atmospheric circular characteristics at the surroundings of the Korean peninsula. Yellow Sand days data are used by intensity, Siberian High Index and monthly mean temperature of the Northern Hemisphere. In the Middle-western region, the occurrence frequency of Yellow Sand days was higher during the study period (1973-2004). Also, the occurrence frequency of Yellow Sand days increased to latter half 16 years compared with the first half 16 years, and be clearer in Middlewest regions. Yellow Sand days frequency increased, and the trend was distinct in the Jungbu region during the study period. Increasing trend of Yellow Sand days frequency was significant for the recent 22 years. Yellow Sand days had a negative relationship with Siberian High Index in February and March. Therefore, Siberian High Index became weaker in the spring, and possibility for the occurrence of Yellow Sand days was generating larger. Yellow Sand days had a positive relationship in monthly mean temperature of the Northern Hemisphere. Especially, the case of the strong Yellow Sand days is significant. Recently, global warming might be affecting the occurrence of strong Yellow Sand days.

• Journal of the Korean Society of Safety
• /
• v.20 no.3 s.71
• /
• pp.64-70
• /
• 2005

In this literature, fault detection and classification of faulty induction motors are carried out through Z-index and frequency analysis. Above frequency analysis refer Fourier transformation and Wavelet transformation. Z-index is defined as the similar form of energy function, also the faulty and healthy conditions are classified through Z-index. For the detection and classification feature extraction for the fault detection of an induction motor is carried out using the information from stator current. Fourier and Wavelet transforms are applied to detect the characteristics under the healthy and various faulty conditions. We can obtain feature vectors from two transformations, and the results illustrate that the feature vectors are complementary each other.

• Journal of Nutrition and Health
• /
• v.33 no.6
• /
• pp.675-683
• /
• 2000

The purpose of this study was to find out the prevalence of constipation nutrition knowledge on dietary fiber and frequency of dietary fiber foods intake of 3rd grade high school girls in Kangnung and Seoul. The total 412 questionnaires were analyzed. Defecation frequency was irregular in 47.6% of the students 21.6% had less than twice a week. Those who were in a hurry during defecation frequency was irregular in 47.6% of the students 21.6% had less than twice a week. Those who were in a hurry during defecation were 57.9% and those spent more than 10 min. for defecation were 21.8% More than half of the students(56.6%) answered to have constipation and 13.8% had taken laxative pills more than once during the last one month period. The nutrition knowledge score was relatively high 7.63 points out of possible 10. Dietary fiber intake scores measured by food frequency questionnaire were 3.78 for fruits 3.71 points out of possible 10. Dietary fiber food intake scores measured by food frequency questionnaire were 3.78 for fruits 3.71 for vegetables and 3.37 for seaweeds meaning taken once a week to 2-3 times per month. For the diagnosis of defecation difficulty a factor called "constipation index" was introduced which was composed of defecation frequency time spending for defecation easiness in defecation and feeling of residue in the intestine after defecation. The Cronbach a coefficient of constipation index was 71. Constipation index was significantly correlated with stress level(p<0.05) haste during defecation(p<.01) and defecation time(p<.01) The higher the stress level the more hurry during defecation and the later the defecation the higher the constipation index. The students who ate more often vegetables and seaweeds had lower constipation index(p<.05, p<.01)05, p<.01)

• Journal of Biomedical Engineering Research
• /
• v.28 no.6
• /
• pp.750-755
• /
• 2007

The linear SEF (Spectral Edge Frequency) parameter and spectrum analysis method can not reflect the non-linear of EEG. This method can not contribute to acquire real time analysis and obtain a high confidence in the clinic due to low discrimination. To solve the problems, the development of a new index is carried out using the bispectrum analyzing the EEG including the non-linear characteristic. At the bispectrum analysis of the 2 dimension, the most significant's power spectrum density peaks appeared much at the specific area in awake and anesthesia state. Because many peaks are showed at the specific area in the frequency coordinate, these points are used to create the new index. Range of the index is 0-100. At the anesthesia, the index is 20-50 and at the awake, the index is 90-60. New index can discriminate the awake and anesthesia state.

• Journal of Urban Science
• /
• v.11 no.2
• /
• pp.9-17
• /
• 2022

The purpose of this study is to develop an index for evaluating the function of a new motorway using the travel distance frequency distribution (TLFD) calculated using the vehicle travel route big data, and to overcome the limitations of the evaluation through the existing traffic volume. The mobility evaluation index of motorways was developed by applying it to the TLFD data table in 2019. The smaller the value of the mobility evaluation index of the link is calculated, the more it is a link with mainly short-distance travel, and the higher the value of the mobility evaluation index, the more it means a link with mainly long-distance travel. The accessibility evaluation index was calculated through the result of the mobility evaluation index of all motorways developed, and all motorways were grouped into three groups using K-means clustering. Group A was found to exist inside a large city and consisted of motorways with many short-distance traffic, Group B was investigated as acting as an arterial between groups, and Group C was classified as a motorway consisting mainly of long-distance traffic connecting large cities and large cities. This study is significant in developing a new motorway function evaluation index that can overcome the limitations of motorway function evaluation through the existing traffic volume. It is expected that this study can be a reasonable comprehensive indicator in the operation and planning process of motorways.

• Journal of the Korean Society of Physical Medicine
• /
• v.19 no.1
• /
• pp.43-51
• /
• 2024

PURPOSE: Sarcopenic obesity (SO) is a clinical condition that combines sarcopenia and obesity. This study examined the frequency of SO in young Korean females between 20 and 29 years of age. METHODS: The study involved 1,000 participants. The height, weight, body mass index (BMI), waist circumference, skeletal muscle mass index, fasting glucose, triglyceride, total cholesterol levels, systolic and diastolic blood pressure, alcohol consumption, and smoking status were the research variables. The skeletal muscle mass index was calculated as appendicular skeletal muscle mass (ASM) divided by the BMI. The ASM was assessed using dual X-ray absorptiometry. Complex sampling analysis and multiple logistic regression were used for analysis. RESULTS: A .74(.30-1.80) frequency of SO was observed. The statistically significant risk factors in females were height, weight, BMI, waist circumference, skeletal muscle mass index, total cholesterol, systolic blood pressure, and diastolic blood pressure (p < .05). CONCLUSION: Young Korean adults with SO have a .74(.30-1.80) frequency of occurrence that is linked to specific risk factors. Hence, primary care clinicians and health care professionals should consider these factors when patients require a referral for early detection and treatment. Healthcare professionals and clinicians can identify potential SO patients by acknowledging these risk factors.

• Journal of Korean society of Dental Hygiene
• /
• v.13 no.2
• /
• pp.261-269
• /
• 2013

Objectives : This research examined the Patient Hygiene Performance(PHP) index according to smoking and tooth brushing behavior, in order to analyze how they influence the oral hygiene. Methods : This research used PHP index and the structured questionnaire. The subjects were 203 men in their 20's who visited K university's dental hygiene department for oral prophylaxis from March to July of 2012. For data analysis SPSS WIN 12.0 was used. Results : 1. The average PHP index of all experimented subjects was 2.66, a very poor level. The PHP index according to general characteristics, smoking, drinking, and exercise showed statistical significance(p<0.05). 2. PHP index decreased with more frequencies and longer durations of toothbrushing(p<0.05). 3. The PHP index of smokers is higher than that of non-smokers. In the case of non-smokers, the frequency, method, and duration of tooth brushing had a statistical significance(p<0.05). 4. The PHP index of smokers who smoke less than or equal to ten cigarettes is 2.53 and smokers who smoked more than 10 cigarettes is 3.10. 5. The results of multiple regression analysis showed that smoking increased the PHP index, while the increase in tooth brushing frequency and the up and down tooth brushing method decreased the PHP index. All the coefficients were statistically significant (p<0.05). Conclusions : In order to increase Patient Hygiene Performance(PHP) index. there must be a decrease in smoking rate while people increase their tooth brushing frequency and use a proper tooth brushing method.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.22 no.11
• /
• pp.1113-1120
• /
• 2012

This paper deals with the analysis of interior noise and low frequency noise characteristic for the Busan citizens to use public transport, Busan Metro Line 3. The interior noise evaluation index, articulation index(AI) is evaluated the lower value about average 22 % in a whole range, this is difficult to have a conversation. Also, noise criteria(NC) curve is partially evaluated as NC-65 below 2000 Hz, space type is evaluated as factories. Another of interior noise evaluation index, preferred speech interference level(PSIL) is evaluated the upper value about average 66 dB(A) in a whole range, this is evaluated to be interrupted. In the case of low frequency noise(20~200 Hz), the measurement of low frequency noise is assessed largely beyond noise criteria of ISO 226. The low frequency noise should be reduced because low frequency noise affects on psychological stress and displeasure although low frequency noise is not recognized by auditory sense. The low frequency noise criteria and guideline will be enacted from now on in Korea.