• 제목/요약/키워드: CORRELATIONS

검색결과 9,801건 처리시간 0.037초

Flow Efficiency in Multi-Louvered Fins Having Large Louver-to-Fin Pitch Ratio

  • Kim, Nae-Hyun;Cho, Jin-Pyo;Kim, Do-Young;Kim, Hyun-Jin
    • International Journal of Air-Conditioning and Refrigeration
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    • 제15권4호
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    • pp.156-162
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    • 2007
  • Flow visualization experiments were conducted for two louver arrays having large louver pitch ratio ($L_p/F_p=1.0$ and 1.4). Flow efficiencies and critical Reynolds numbers were obtained from the data, and were compared with existing correlations. The correlations failed to predict the present flow efficiency data adequately; some correlation overpredicted the data, while others underpredicted the data. Large louver pitch ratio of the present model, which is outside of the applicable range of the correlations may partly be responsible. The critical Reynolds numbers obtained from the present flow visualization data were in close agreement with those obtained from the heat transfer tests on actual flat tube heat exchangers. Existing correlations on the critical Reynolds number generally overpredicted the present data.

Crime amount prediction based on 2D convolution and long short-term memory neural network

  • Dong, Qifen;Ye, Ruihui;Li, Guojun
    • ETRI Journal
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    • 제44권2호
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    • pp.208-219
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    • 2022
  • Crime amount prediction is crucial for optimizing the police patrols' arrangement in each region of a city. First, we analyzed spatiotemporal correlations of the crime data and the relationships between crime and related auxiliary data, including points-of-interest (POI), public service complaints, and demographics. Then, we proposed a crime amount prediction model based on 2D convolution and long short-term memory neural network (2DCONV-LSTM). The proposed model captures the spatiotemporal correlations in the crime data, and the crime-related auxiliary data are used to enhance the regional spatial features. Extensive experiments on real-world datasets are conducted. Results demonstrated that capturing both temporal and spatial correlations in crime data and using auxiliary data to extract regional spatial features improve the prediction performance. In the best case scenario, the proposed model reduces the prediction error by at least 17.8% and 8.2% compared with support vector regression (SVR) and LSTM, respectively. Moreover, excessive auxiliary data reduce model performance because of the presence of redundant information.

Quantum Coherent Dissociation in a Hybrid Atom-light System with Photon Loss

  • Xiaoyang Yuan;Jialu Yin;Jiahao Xu;Yixiao Huang;Zhengda Hu
    • Current Optics and Photonics
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    • 제8권1호
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    • pp.105-111
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    • 2024
  • We investigate the effect of photon loss on pair production in a hybrid atom-light system. The loss of light field not only affects the generation of photons, but also prevents the generation of atomic collective excitation, although the atoms are not influenced directly. We propose an unbalanced homodyne detection of the number of atomic collective excitation that overcomes the challenge caused by counting uncertainty in practical measurement. In discussion, we show that the intermode correlations and the number correlation is closely related to the initial input state, while the quadrature correlations are independent of the initial state and always exhibit opposite intermode correlations even in the presence of loss.

Correlation Study of Temporal and Emission Properties of Quiescent Magnetars

  • Jiwoo Seo;Jaewon Lee;Hongjun An
    • 천문학회지
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    • 제56권1호
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    • pp.41-57
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    • 2023
  • We measured temporal and emission properties of quiescent magnetars using archival Chandra and XMM-Newton data, produced a list of the properties for 17 magnetars, and revisited previously suggested correlations between the properties. Our studies carried out with a larger sample, better spectral characterizations, and more thorough analyses not only confirmed previously-suggested correlations but also found new ones. The observed correlations differ from those seen in other neutron-star populations but generally accord with magnetar models. Specifically, the trends of the intriguing correlations of blackbody luminosity (LBB) with the spin-inferred dipole magnetic field strength (BS) and characteristic age (τc) were measured to be LBB ∝ B1.5S and LBB ∝ τ-0.6c, supporting the twisted magnetosphere and magnetothermal evolution models for magnetars. We report the analysis results and discuss our findings in the context of magnetar models.

광주지역 일부 초등학교 저학년 아동의 식습관과 영양소 섭취량 및 혈액성상에 관한 연구 (The Eating Behaviors, Nutrient Intakes and Hematological Status of the Lower Grade Primary School Children in Gwangiu)

  • 황금희;정난회;유맹자
    • 한국식품영양학회지
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    • 제14권4호
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    • pp.293-299
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    • 2001
  • The purpose of this study was to examine height, weight. chest circumference, sitting height, hematological status. eating behaviors and nutrient intakes for the lower grade primary school children in Gwangju. The subjects consisted of 76 boys and 60 girls aged 9 years old. Height, Weight, Chest circumference, Sitting height, Hct, WBC, RBC, Hb, serum GOT, GPT and cholesterol were measured. With regard to regularity of meal time, 66.7% of the subjects has been 'regular'. With regaled to amount of eaten food, 100.0% of the subjects has been 'moderate'. With regard to nutritional balance, 66.6% of the subjects has been 'think,but do not practice'. The study also found that 100.0% of the subjects skipped breakfast, liked korean food. Their dietary intake vase assesed for 1 day by means of 24 hours dietary recall method. The mean energy intake of the subjects was 1,306 kcal. The subjects consumed 47.9g protein, 28.8g lipid, 3.9g fiber, 446.9mg calcium, 835.0mg phosphorous, 7.9mg iron, 3,721mg sodium, 1.863mg potassium, 362.3RE retinol, 0.8mg thiamin, 1.1mg riboflavin, 10.8NE niacin, 93.9mg ascorbic acrid and 173.5mg cholesterol respectively. Energy, protein, calcium, iron, retinol, thiamin, riboflavin and niacin intake was lower than the Korean RDA. There were positive correlations between meal time and protein intake or fat intake or fiber intake or iron intake or retinol intake : negative correlations between meal time and sodium intake negative correlations between saltiness and cholesterol intake positive correlations between use of perilla seeds and riboflavin intake or niacin intake : negative correlations between energy intake or carbohydrate intake or phosphorous intake : negative correlations between frequency of eating-out and protein intake or fat intake or fiber intake or iron intake or retinol intake or thiamin intake or riboflavin intake or niacin intake.

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2D:4D 비율과 MMPI-2의 상관관계 연구 (Correlation between 2D:4D Ratio and Minnesota Multiphasic Personality Inventory-2 Questionnaire)

  • 권오현;이재혁
    • 동의신경정신과학회지
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    • 제29권2호
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    • pp.69-77
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    • 2018
  • Objectives: To determine the relationship between 2D:4D ratio and Minnesota Multiphasic Personality Inventory-2 Questionnaire (MMPI-2 scales). Methods: The 2D:4D ratio in 101 Korean medical students was measured. MMPI-2 test was performed. Results: In the unisex group, there were significantly positive correlations between the 2D:4D ratio and MMPI-2 scales of Hs, D, Pt, Sc, Si, RC1, RC2, RC8, INTR, ANX, OBS, HEA, BIZ, LSE, WRK, TRT, A, R, Mt, PK, and AAS while there were significantly negative correlations between the 2D:4D ratio and MMPI-2 scales of Es and Do. In the male group, there were significantly positive correlations between the 2D:4D ratio and MMPI-2 scales of Hs, RC1, RC8, HEA, and AAS while there were significantly negative correlations between the 2D:4D ratio and MMPI-2 scale of AGGR. In the female group, the 2D:4D ratio showed significantly positive correlations with MMPI-2 scales of Pt, Sc, Si, RC1, RC2, RC6, INTR, DEP, BIZ, LSE, WRK, A, Mt, PK, and Ho while it showed significantly negative correlations with MMPI-2 scale of Do. Conclusions: MMPI-2 scales are correlated with the 2D: 4D ratio. Therefore, 2D: 4D ratio could be used as an indicator to reflect multiphasic personality of individuals.

Genetic Evaluation of First Lactation Traits in Sahiwal Cattle Using Restricted Maximum Likelihood Technique

  • Choudhary, V.;Kothekar, M.D.;Raheja, K.L.;Kasturiwale, N.N.;Khire, D.W.;Kumar, P.
    • Asian-Australasian Journal of Animal Sciences
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    • 제16권5호
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    • pp.639-643
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    • 2003
  • The data on 283 Sahiwal cows, sired by 16 bulls, maintained at Cattle Breeding Farm of Nagpur Veterinary College and Dairy Farm of Agricultural College, Nagpur, were considered for the estimation of genetic parameters. Variance and covariance estimates of first lactation traits were obtained using restricted maximum likelihood technique (REML). When first lactation milk yield (FLMY), first lactation length (FLL) and average daily yield (ADY) traits were considered for REML analysis, the heritabilities were $0.184{\pm}0.146$, $0.132{\pm}0.131$ and $0.141{\pm}0.133$, respectively. While, genetic and phenotypic correlations between them were medium to high except phenotypic correlations between FLL and ADY (-0.025). REML procedure considering FLMY, age at first calving (AFC) and first service period (FSP) combination exhibits heritabilities as $0.274{\pm}0.173$, $0.506{\pm}0.233$ and $0.274{\pm}0.172$, respectively. Genetic correlations were $-0.120{\pm}0.376$, $0.225{\pm}0.423$ and $0.365{\pm}0.331$ between FLMY and AFC, FLMY and FSP, AFC and FSP, respectively. Phenotypic correlations were 0.057, 0.289 and 0.123, respectively. Considering all five traits REML combination heritabilities estimated were $0.238{\pm}0.162$, $0.160{\pm}0.139$, $0.136{\pm}0.132$, $0.409{\pm}0.209$ and $0.259{\pm}0.168$ for FLMY, FLL, ADY, AFC and FSP, respectively. The genetic correlations were positive except FLMY and AFC. The phenotypic correlations were also positive except FLL and ADY, ADY and FSP. Almost all estimates were associated with high standard error.

다문화 가족 청소년의 성별에 따른 건강행위와 건강상태의 비교 (Health Behaviors and Health Status by Gender Differences of Adolescents in Multicultural Families)

  • 김은경;유하나
    • 한국학교보건학회지
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    • 제31권1호
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    • pp.10-17
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    • 2018
  • Purpose: The purpose of this study was to examine the health behaviors and health status of adolescents in multicultural families according to gender. Methods: The study used raw data of the Korean Youth Risk Behavior Web-Based Survey performed in 2016. The 12th survey was conducted on 67,983 adolescents in 400 middle schools and 400 high schools. Among them, 759 adolescents were included in this study. Their data were analyzed using descriptive statistics, $x^2$-test, and Pearson's correlation. Results: There were significant differences in economic status, smoking experience, age of drinking onset, vigorous physical activity, soft drink consumption, toothbrushing after lunch, handwashing with soap before eating at school and eating at home and after coming home, BMI, subjective health status, stress, depression, and allergic rhinitis according to gender in multicultural adolescents. For boys, significant positive correlations were found between age and the age of drinking onset, between academic achievement and economic status, and between the age of smoking initiation and the age of drinking onset. However, there were significant negative correlations between economic status and stress and between subjective health status and stress. For girls, age had positive correlations with academic achievement, the age of drinking onset, BMI, and stress and economic status had positive correlations with academic achievement, the age of smoking initiation, and subjective health status. Also, the age of smoking initiation had positive correlations with the age of drinking onset and BMI. Lastly, there were negative correlations between age and economic status, between age and subjective health status, academic achievement and the age of smoking initiation, economic status and stress, and subjective health status and stress. Conclusion: The results of this study are expected to be useful as basic data for planning health interventions for boys and girls in multicultural families.

학술논문 분석을 통한 기상민감질환 선정 및 기상인자와의 관련성고찰 (Weather-sensitive Diseases and Their Correlations with Meteorological Factors: Results from Academic Papers)

  • 안혜연;정주희;김태희;윤진아;김현수;오인보;이지호;원경미;이영미;김유근
    • 한국환경과학회지
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    • 제25권6호
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    • pp.839-851
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    • 2016
  • The effect of weather on disease was investigated based on results reported in academic papers. Weather-sensitive disease was selected by analyzing the frequency distributions of diseases and correlations between diseases and meteorological factors (e.g., temperature, humidity, pressure, and wind speed). Correlations between disease and meteorological factors were most frequently reported for myocardial infarction (MI) (28%) followed by chronic ischemic heart disease (CHR) (12%), stroke (STR) (10%), and angina pectoris (ANG) (5%). These four diseases had significant correlations with temperature (meaningful correlation for MI and negative correlations for CHR, STR, and ANG). Selecting MI, as a representative weather-sensitive disease, and summarizing the quantitative correlations with meteorological factors revealed that, daily hospital admissions for MI increased approximately 1.7%-2.2% with each $1^{\circ}C$ decrease in physiologically equivalent temperature. On the days when MI occurred in three or more patients larger daily temperature ranges ($2.3^{\circ}C$ increase) were reported compared with the days when MI occurred in fewer than three patients. In addition, variations in pressure (10 mbar, 1016 mbar standard) and relative humidity (10%) contributed to an 11%-12% increase in deaths from MI and an approximately 10% increase in the incidence of MI, respectively.

국내 기후변화 관련 감염병과 기상요인간의 상관성 (Correlations Between Climate Change-Related Infectious Diseases and Meteorological Factors in Korea)

  • 김시헌;장재연
    • Journal of Preventive Medicine and Public Health
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    • 제43권5호
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    • pp.436-444
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    • 2010
  • Objectives: Infectious diseases are known to be affected by climate change. We investigated if the infectious diseases were related to meteorological factors in Korea. Methods: Scrub typhus, hemorrhagic fever with renal syndrome (HFRS), leptospirosis, malaria and Vibrio vulnificus sepsis among the National Notifiable Infectious Diseases were selected as the climate change-related infectious diseases. Temperature, relative humidity and precipitation were used as meteorological factors. The study period was from 2001 through 2008. We examined the seasonality of the diseases and those correlations with meteorological factors. We also analyzed the correlations between the incidences of the diseases during the outbreak periods and monthly meteorological factors in the hyper-endemic regions. Results: All of the investigated diseases showed strong seasonality; malaria and V. vulnificus sepsis were prevalent in summer and scrub typhus, HFRS and leptospirosis were prevalent in the autumn. There were significant correlations between the monthly numbers of cases and all the meteorological factors for malaria and V. vulnificus sepsis, but there were no correlation for the other diseases. However, the incidence of scrub typhus in hyper-endemic region during the outbreak period was positively correlated with temperature and humidity during the summer. The incidences of HFRS and leptospirosis had positive correlations with precipitation in November and temperature and humidity in February, respectively. V. vulnificus sepsis showed positive correlations with precipitation in April/May/July. Conclusions: In Korea, the incidences of the infectious diseases were correlated with meteorological factors, and this implies that the incidences could be influenced by climate change.