• Title/Summary/Keyword: frequency and correlation analysis

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Enhanced Analysis Method of MIMO Channel Characteristics with Antenna Correlation at 781MHz (781MHz 대역에서 안테나 상관도를 고려한 개선된 MIMO 채널 특성 분석 방법)

  • Jung, Myoung-Won;Chong, Young-Jun;Pack, Jeong-Ki
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.13 no.3
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    • pp.17-24
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    • 2013
  • In this paper, the measurement data is analyzed and channel characteristics are derived through MIMO Channel measurements at 781MHz considering antenna correlation. 781MHz frequency band currently operates the DTV system, however, it will be allocated new mobile communication frequency band. The channel characteristics at 781MHz seem to be similar existing mobile communication system at 900MHz but quite a different part of the existing research has demonstrated. In addition, the signal procedure of the channel characteristics, considering the correlation of the antenna, for a more accurate prediction research is needed. To avoid interference with Korean DTV broadcasting, we measured channel characteristics in urban areas of Jeju island by channel sounder and $4{\times}4$ antenna. Channel characteristics with antenna correlation were derived based on the measured data in the urban area.

Comparison of the Levels of Nutrient Intakes by Different Dietary Methods and Days of Dietary Studies Among Young Females in Korea (식이섭취조사방법과 조사일수에 따른 한국 젊은 여성의 영양소 섭취 수준의 비교)

  • 오세영
    • Journal of Nutrition and Health
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    • v.29 no.9
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    • pp.1021-1027
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    • 1996
  • This study examined the patterns of nutrient intakes measured by 1-, 3-, 7-day recalls and records as well as food frequency questionnaire among 59 females volunteers enrolled in the university in Seoul, Korea. Over a 4 month period, a modified Willett food frequency questionnaire was administered once, and a 24-hour dietary recall was conducted 12 times and a weighted dietary record 14 times. From these 12 recalls and 14 records, 1-, 3-, 7-day data were randomly selected. For energy and 11 nutrients, group mean intakes derived from food frequency questionnaire were higher than from recalls and records. Group mean intakes from recalls and records showed little differences depending on days of dietary studies and dietary methods. Measures of agreement were calculated by weighted kappa and intraclass correlation coefficient values calculated for quintile categories while comparing to the results of 26 days recalls and records. Weighted kappa values ranged from 0.11 for riboflavin to 0.36 for vitamin C for and 1-day recall, and from 0.21 for iron to 0.31 for energy for the 1-day record. Weighted kappa values were increased as the number of days of dietary studies increased (0.34-0.57 for the 3-day recalls, 0.27-0.50 for the 3-day records, 0.50-0.68 for the 7-day recalls, and 0.50-0.65 for the 7-day records). Weighted kappa values for food frequency questionnaire were higher than the 1-day data, but lower than the 3-and-7day data(0.34 for energy, 0.31 for iron and 0.22 for vitamin C). Intraclass correlation coefficients ranged from 0.21 for vitamin A to 0.57 for calcium. The degrees of agreement by different methods and days of dietary study are lower in our study compared to agreement by different methods and days of dietary study are lower in our study compared to those in previously published studies for Western populations, partly due to the differences of data analysis methods as well as of dietary patterns between those samples and ours.

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Mediating Effects of Diet Quality between Meal Frequency and Cardiometabolic Risk among Korean Adults: Data from the 7th Korea National Health and Nutrition Examination Survey (KNHNES) (한국 성인의 식사 빈도에 따른 심혈관대사질환 위험도와 식사 질의 매개효과 : 국민건강영양조사 제7기 자료)

  • Cho, Yoo Mi;Lee, Kyoung Suk
    • Journal of Korean Critical Care Nursing
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    • v.16 no.2
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    • pp.67-80
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    • 2023
  • Purpose : The 2020 Dietary Guidelines Advisory Committee specifically noted that meal frequency is associated with risks for cardiovascular disease, type 2 diabetes, and all-cause mortality, although the current evidence on meal frequency is conflicting. As meal frequency itself is affected by various factors, the aim of the study was not only to examine its relationships with cardiometabolic risk but also to identify the mediating effects of dietary quality. Methods : This study used a descriptive correlational design. In all 8,141 healthy adults participated in the study. Measurements included meal frequency, cardiometabolic risk, and diet quality. Data were analyzed using descriptive statistics, Pearson's correlation coefficient analysis, and process macro bootstrapping model 4. Results : The meal frequency was 3.52±0.61 times per day, the risk of cardiovascular metabolic diseases was 0.01±0.61 points, and the diet quality was 62.08±13.87 points. In mediation analysis, the effect of meal frequency on cardiometabolic risk score was completely mediated by diet quality. Conclusion : Improved diet quality in healthy adults should be considered when designing meal frequency interventions aimed at reducing their cardiometabolic risk, as the effect of meal frequency support on cardiometabolic risk was found to be mediated by diet quality.

A Study on the Factors which affect the Oral Health Care of Infants (유아의 구강보건관리에 영향을 미치는 요인에 관한 연구)

  • Kim, Seol-Ag
    • Journal of the Korean Society of School Health
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    • v.8 no.2
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    • pp.315-326
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    • 1995
  • This study was performed to find variables which affect oral health care of infants. The subjects were 439 infants and their mothers who live in suburban area. Oral examinations for the infants were conducted and the questionnairs were given to infants' mothers. Toothbrushing frequency, oral hygiene score, the percentage of filled teeth among decayed teeth, and dental treatment experience of infants were used as dependent variable, respectively. Demographic, socio-economic variables and the other variables which might affect oral health care of infants were used as independent variables. Correlation analysis and analysis of variance were used for the independent variables of toothbrushing frequency, oral hygiene score, and the percentage of filled teeth among decayed teeth of infant. Chi-Square and Student's t-test were used for the dependent variables of dental treatment experience of infant. The obtained results were as follows; 1. Toothbrushing frequency of mother and internal locus of oral control of mother were the factors which affect toothbrusing frequency of infants. 2. Oral health belief of mother was the factor which affect oral hygiene score of infants. 3. Age of infant was the factor which affect the percentage of filled teeth among decayed teeth. 4. Age of infant and educational level of infant's mother were the factors which affect the infants' consumption of dental treatment.

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Relationship between Rustling Sounds and Physical Properties of Suiting fabrics (슈트용 직물의 스치는 소리와 물성간의 관계)

  • 조길수;이은주
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 1999.03a
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    • pp.271-276
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    • 1999
  • This study was carried out to investigate the relationship between sound color and physical propertiessuiting fabrics. Rustling sounds of 23 suiting fabrics by sound generator developed for this study were recorded and analysed through FFT analysis. Three sound color factor(ΔL Δf. LPT) were obtained.Physical properties of specimens were measured by KES-FB. Level range(L) showed significant correlation with tensile resilience(RT) and thickness (T). Frequency difference(Δf) showed significant correlation with tensile linearity(LT), shear properties(G, 2HG, 2HG5), compressional energy(WC), and weight(W). Total sound pressure (LPT) showed significant correlation with elongation at maximum load (EM), tensile linearity(LY), and tesile energy(WT). By stepwise regression LPT was found to be explained by EM, MIU, RC, LT significantly.

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Wavenumber correlation analysis of satellite magnetometer observations

  • Kim, Jeong-Woo;Kim, Won-Kyun;Kim, Hye-Yun
    • Proceedings of the KSEEG Conference
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    • 2000.04b
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    • pp.311-313
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    • 2000
  • Identifying anomaly correlations between data sets is the basis for rationalizing geopotenial interpretation and theory. A procedure between the two or more geopotential data sets. Anomaly features that show direct, inverse, or no correlationsbetween the data may be separated by applying filters in the frequency domains of the data sets. The correlation filter passes or rejects wavenumbers between co-registered data sets based on the correlation coefficient between common wavenumbers as given by the cosine of their phase difference. This study includes as example of Magsat magnetic anomaly profile that illustrates the usefulness of the procedure for extracting correlative features between the sets.

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The Structural Correlation between Consumer's Attitudes and Intention of Repurchase of Home Meal Replacement (HMR) according to the Product Categories (가정식사 대용식(HMR) 제품 유형별 재구매 의도와 소비자 태도 구성개념간의 구조적 관련성 검증)

  • Chung, La-Na;Lee, Hae-Young;Yang, Il-Sun
    • Korean Journal of Community Nutrition
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    • v.12 no.3
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    • pp.344-351
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    • 2007
  • The purposes of this study were to analyze the consumer inclination to convenience towards HMR in order to verify the structural correlation of the actual state of consumption, and to analyze consequently, the direct or indirect effects among 'frequency of using,' 'preference', 'satisfaction', and 'intention to repurchase'. The subjects were adults in their twenties or older who had used HMRs and lived in Seoul and Gyeonggi Province in Korea. Random sampling of 550 subjects, who were distributed a questionnaire from March 12 to 30, 2005. A total of 451 questionnaires were returned (the return rates were 82%). The main results of this study were as follows : Regarding the types of HMR, 'Ready to eat' had higher preference (3.31), satisfaction (3.33) and 'intention to purchase it again' (3.38) than those of 'Ready to heat' and 'Ready to end-cook.' Consumer inclination to convenience towards HMR was analyzed in order to verify the structural correlation of the actual state of consumption, and consequently, the direct or indirect effects among 'frequency of using,' 'preference', 'satisfaction', and 'intention to repurchase' were analyzed. The gross effect of 'frequency of using' on 'intention to repurchase' was 0.435, the gross effect of preference on 'intention to purchase it again' was 0.659, and the gross effect of satisfaction on 'intention to purchase it again' was 0.772 for 'Ready to eat.' The gross effect of 'frequency of using' on 'intention to repurchase' was 0.448, the gross effect of preference on 'intention to repurchase' was 0.556, and the gross effect of satisfaction on 'intention to repurchase' was 0.654 for 'Ready to heat.' The gross effect of 'frequency of using' on 'intention to repurchase' was 0.432, the gross effect of preference on 'intention to repurchase' was 0.494, and the gross effect of satisfaction on 'intention to repurchase' was 0.608 for 'Ready to end-cook.' To summerize the above results, there was a difference of the structural correlation among component concepts of the actual state of consuming according to the criteria of HMR. Thus, it implied that differentiated sales strategies were needed according to the criteria of HMR.

Threshold detection technique for code acquisition using maximum mismatched correlation value (부정합된 최대 상관값을 이용한 초기 동기 임계치 결정 기법)

  • 유영환;김종헌;강성철;강창언
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.7
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    • pp.1803-1813
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    • 1996
  • This paper describes an automatic threshold decision using a maximum mismatched correlation value in the direct sequence spread spectrum (DS-SS) system. For received PN codes with different single-to-noise ratio (SNR), this scheme is able to detect a desired threshold value in the search mode, i.e. a maximum mismstched correlation value, so that value is utilized as a threshold for the verification mode. Performance of the proposed scheme in both the additive white gaussian noise (AWGN) and frequency-selective Rayleigh fading channels is analyzed through the Monte Carlo simulation. And hardware implementation of this scheme using a DSP processor is demonstrated. The proposed acquisition shceme is compared to the conventional constant threshold (CT) scheme, and significant improvement of performance is shown. Analysis of system performance in the verification mode is presented, and key quantities such as the false alarm probability and the detection probability are derived in a AWGN channel.

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Analysis of the Factors and the Differences in the Awareness about the Capability Groups of the Mediator Manager in General Hospital and the Level of Performance (종합병원 중간관리자의 역량군별 중요도 인식과 수행수준 차이 및 요인분석)

  • Kim, Hee-Sook;Jo, Woo-Hyun;Kim, Young-Hoon;Kim, Tae-Hyun
    • Korea Journal of Hospital Management
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    • v.16 no.3
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    • pp.92-114
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    • 2011
  • The study has its purpose on providing basic resource to enforce the capability of the middle managers by examining the level of performance and the level of awareness about the capabilities of the managers and by understanding the significance of the difference and the reasons for the differences. The source of the study was 195 survey questionnaires that were carried out to the managers of the 9 general hospitals and the method of the analysis was the frequency analysis, analysis of the credibility, matching to sample T-test, independent sample T-test, dispersion analysis, correlation analysis, and multiple linear regression analysis using accumulated variables. The followings are the main result of the study. First, the difference between the level of awareness about the capabilities and the level of performance of the mediator managers in general hospitals had high capability in change management. The following orders were: competence in achievement and behavior, competence in management, competence in recognition, competence in influence, competence in individual effectiveness, and competence in personal relationship service. Second, as the result of the relation analysis in order to understand the correlation between awareness and performance of the mediator managers, everything had significant positive correlation. In the study about the level of importance, the cognitive capability and the management capability had the highest correlation with the correlation number of 0.88. In the study about the level of performance, the cognitive capability, individual capability, and the management capability had the highest correlation with the correlation variable number of 0.79. Third, as the result of studying the reason for the difference between the level of the awareness capability and the level of the performance, lack of the support recognition compensation in the organization level, inappropriate work environment, limit in the regulation were found as the highest reason in the order. As the result of the study, it was concluded that the creation of the efficient capability estimation model and the securement of the system that estimate the capability of the managers should be carried out in order to enforce the capability of the mediator managers in general hospitals.

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The Study of Classification Body Types of Adults Women and Drawing of Prototype of Clothing (성인여성의 의복 원형 개발에 관한 연구 -성인여성의 체형 분류에 관한 연구의 후속 연구-)

  • 손혜순;손혜정
    • The Research Journal of the Costume Culture
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    • v.5 no.4
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    • pp.130-158
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    • 1997
  • This study outputs calculation of regression of each items for production of torso basic pattern according to 6 body types as the result of another study and intends to present drawing method of torso model by short measure method modified and supplied and supplied by experiments of wearing clothing. SAS(Statistical Analysis System) is used for figures management and methods for analysis used are Frequency Analysis, Means Analysis, Regression Analysis, Correlation Analysis, etc. Results are as follows. 1. Correlation analysis is used to output the size necessary for torso prototype drawing by sort measure method and waist front length, back length, crotch length, shoulder point-cerricale-shoulder point, bust circumference, waist circumference, weight, etc, are set up as representative items calculation of regression of each type is suggested. 2. In the result of experiment of the first wearing clothing intended for 5 in each type and the whole 30, to develop torso prototype drawing method by short measure method, as we find some problems of the shape and propriety of neck root circumference line, the position of shoulder point, pulling or hold armpit parts, waist circumference line, the degree of dissatisfaction is high, so the second experiment of wearing clothing is propriety of each part is improved, all items except the length and quantity of shoulder dart, waist in back bodice, clearance quantity of hip circumference, and the place of shoulder line in side bodice. So, it was modifed and supplied and then the third torso prototyped drawing method by shout measure method was suggested. The third prototype drawing method was suggested, by modifying and supplying.

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