• 제목/요약/키워드: Partial Correlation

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영상집적 기반의 다시점 부호화 기술을 이용한 디지털 홀로그램의 압축 기술 (Digital Hologram Compression Technique using Multi-View Prediction based on Image Accumulation)

  • 최현준;서영호;배진우;유지상;김화성;김동욱
    • 한국통신학회논문지
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    • 제31권10C호
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    • pp.933-941
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    • 2006
  • 본 논문에서는 다시점 예측기법과 MPEG 동영상 압축 표준 기법을 이용하여 CCD 카메라로부터 광학적으로 획득되거나 컴퓨터에 의해 생성된 디지털 홀로그램(프린지 패턴)을 효율적으로 압축하는 방법을 제안하였다. 이 방법은 RGB의 각 색차신호를 분리하여 처리하고, 각 색차신호의 객체영상을 $N{\times}N$ 크기로 분할한 부분영상들을 기본단위로 하며, 이때의 각 부분영상은 객체 전체에 대한 정보를 보유하고 있다. 본 논문의 방법은 분할되고 주파수 변환된 한 열의 부분영상들을 다시점 예측기법을 이용하여 집적영상을 만들고, 이 영상을 기준으로 데이터압축을 수행한다. 즉, 이 집적영상에서 역으로 생성된 부분영상과 원 부분영상에 대해 MPEG의 움직임 예측/보상방법으로 데이터를 압축한다. 따라서 압축된 데이터는 집적영상을 만들기 위한 각 부분영상의 변위벡터, 집적영상, 각 부분영상에 대한 움직임벡터 및 보상영상이다. 이 방법을 구현하여 실험한 결과 기존의 방법에 비해 동일 압축율에서의 NC(Normal Correlation) 값이 약 4% 이상 높은 값을 보여 압축효율이 더 좋음을 알 수 있었다. 따라서 본 논문의 방법은 디지털 홀로그램 데이터를 전송하여야 하는 응용분야에서 보다 효율적으로 사용될 수 있을 것으로 기대된다.

Correlation analysis of human urinary metabolites related to gender and obesity using NMR-based metabolic profiling

  • Kim, Ja-Han;Park, Jung-Dae;Park, Sung-Soo;Hwang, Geum-Sook
    • 한국자기공명학회논문지
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    • 제16권1호
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    • pp.46-66
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    • 2012
  • Metabolomic studies using human urine have shown that human metabolism is altered by a variety of environmental, cultural, and physiological factors. Comprehensive information about normal human metabolite profiles is necessary for accurate clinical diagnosis of disease and for disease prevention and treatment. In this study, metabolite correlation analyses, using $^1H$ nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate statistics, were performed on human urine to compare metabolic differences based on gender and/or obesity in healthy human subjects. First, we applied partial least squares discriminant analysis to the NMR spectral data set to verify the data's ability to discriminate by gender and obesity. Then, the differences in metabolite-metabolite correlation between male and female, and between normal and high body mass index (obese) subjects were investigated through pairwise correlations. Creatine and several metabolites, including isoleucine, trans-aconitate, and trimethylamine N-oxide (TMAO), exhibited different quantitative relationships depending on gender. Dimethylamine had a different correlation with glycine and TMAO, based on gender. The correlation of TMAO with amino acids was considerably lower in obese, compared to normal, subjects. We expect that the results will shed light on the metabolic pathways of healthy humans and will assist in the accurate diagnosis of human disease.

Relative contribution of geomagnetic and CO2 effects to global temperature anomaly

  • Kim, Jinhyun;Moon, Yong-Jae
    • 천문학회보
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    • 제41권1호
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    • pp.79.3-80
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    • 2016
  • We have investigated the correlation analysis between global temperature anomaly and two main factors: geomagnetic activity (aa index) of Earth external factor and CO2 of Earth internal factor. For this, we used NOAA Global Surface Temperature anomaly (Ta) data from 1868 to 2015. The aa index indicates the geomagnetic activity measured at two anti-podal subauroral stations (Canberra Australia and Hartland England) and the CO2 data come from historical ice core records and NOAA/ESRL data. From the comparison between (Ta) and aa index, we found several interesting things, First, the linear correlation coefficient between two parameters increases until 1985 and then decreases rapidly. Second, the scattered plot between two parameters shows a boundary of the correlation tendency (positive and negative correlation) near 1985. A partial correlation of (Ta) and two main factors (aa index, CO2) also shows that the geomagnetic effect (aa index) is dominant until about 1985 and the CO2 effect becomes much more important after then. These results indicate that the CO2 effect become very an important factor since at least 1985. For a further analysis, we simply assume that Ta = Ta(aa)+Ta(CO2) and made a linear regression between (Ta) and aa index from 1868 to 2015. A linear model is then made from the linear regression between energy consumption (a proxy of CO2 effect) and Ta-Ta(aa) since 1985. Our results will be discussed in view of the prediction of global warming.

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Partial second toe pulp free flaps in early childhood

  • Hong, Min Ki;Lee, Dong Chul;Choi, Min Suk;Koh, Sung Hoon;Kim, Jin Soo;Roh, Si Young;Lee, Kyung Jin
    • Archives of Plastic Surgery
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    • 제47권6호
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    • pp.590-596
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    • 2020
  • Background The introduction of the partial second toe pulp free flap has enabled superior aesthetic and functional results for fingertip reconstruction in adults. Children undergoing fingertip amputation for various reasons have limited options for reconstruction. Conventional treatment could shorten the finger, leading to poor cosmesis and function. We report 18 years of our experiences with fingertip reconstruction using partial second toe pulp free flaps in patients in early childhood. Methods Medical charts of children who had undergone fingertip reconstruction using partial second toe pulp free flaps from 2001 to 2018 were retrospectively reviewed. The surgical procedures were identical to those for adults, except for the usage of 11-0 nylon sutures. Patients' demographic data, vessel size, flap dimensions, length of the distal phalanx, and functional outcomes over the course of long-term follow-up were documented. The statistical analysis was performed with the Student t-test, the Mann-Whitney U test, and Pearson correlation analysis. Results Eighteen toe pulp flaps in 17 patients (mean age, 3.0 years) were identified. All the flaps survived without any major complications. In long-term follow-up, the flap-covered distal phalanges showed growth in line with regular development. There was no donor-site morbidity, and all children adapted to daily life without any problems. In two-point discrimination tests, the fingertip sensation recovered to almost the same level as that in the contralateral finger. Conclusions Partial second toe pulp free flaps are an excellent option for fingertip reconstruction in young children, as well as in adults.

Partial Confinement Utilization for Rectangular Concrete Columns Subjected to Biaxial Bending and Axial Compression

  • Abd El Fattah, Ahmed M.;Rasheed, Hayder A.;Al-Rahmani, Ahmed H.
    • International Journal of Concrete Structures and Materials
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    • 제11권1호
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    • pp.135-149
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    • 2017
  • The prediction of the actual ultimate capacity of confined concrete columns requires partial confinement utilization under eccentric loading. This is attributed to the reduction in compression zone compared to columns under pure axial compression. Modern codes and standards are introducing the need to perform extreme event analysis under static loads. There has been a number of studies that focused on the analysis and testing of concentric columns. On the other hand, the augmentation of compressive strength due to partial confinement has not been treated before. The higher eccentricity causes smaller confined concrete region in compression yielding smaller increase in strength of concrete. Accordingly, the ultimate eccentric confined strength is gradually reduced from the fully confined value $f_{cc}$ (at zero eccentricity) to the unconfined value $f^{\prime}_c$ (at infinite eccentricity) as a function of the ratio of compression area to total area of each eccentricity. This approach is used to implement an adaptive Mander model for analyzing eccentrically loaded columns. Generalization of the 3D moment of area approach is implemented based on proportional loading, fiber model and the secant stiffness approach, in an incremental-iterative numerical procedure to achieve the equilibrium path of $P-{\varepsilon}$ and $M-{\varphi}$ response up to failure. This numerical analysis is adapted to assess the confining effect in rectangular columns confined with conventional lateral steel. This analysis is validated against experimental data found in the literature showing good correlation to the partial confinement model while rendering the full confinement treatment unsafe.

인용 분석을 통한 학문간 회색문헌의 활용도 비교 연구 (A Comparative Study on Usability of Grey Literature among Sciences, Using Citation Analysis)

  • 조현양
    • 한국문헌정보학회지
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    • 제42권1호
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    • pp.273-294
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    • 2008
  • 이 연구에서는 학문분야별 연구자들이 연구를 수행하는 과정에서 참고하는 주요 정보원을 자료 형태별로, 그리고 7개 학문분야별로 비교. 분석해 보고 이 가운데 회색문헌에 대한 학문 분야별로 선호도에서 어떠한 차이가 있는가를 인용분석을 통하여 확인해 보았다. 분석결과 연구자들의 회색문헌과 백색문헌에 대한 선호도가 분야별로 차이가 나타났으며, 분야와 상관없이 국내에서 발간되는 국, 영문 학술지 사이에서도 그 선호도에 차이가 발견되었다. 또한 동일한 분야 내에서 영문학술지와 국문학술지 사이에 인용된 문헌에 대한 회색문헌과 백색문헌의 두 집단 간에도 선호도 차이가 있음을 보였다. 마지막으로 분야와 언어 변수를 통제한 후 자료 형태별로 편상관계수 값을 통하여 분석한 결과 회의록 자료와 기타자료 사이의 편상관계수 값이 타 형태의 자료에 비해 높은 것으로 나타나 회의록 자료를 많이 인용한 논문은 기타자료도 동시에 인용하는 경향이 있음을 보여 주었다.

간호대학생의 생활 스트레스와 자살생각 간의 관계에서 스트레스 대처방식과 자아존중감의 매개효과 (The Mediating Effect of Stress Coping Type and Self-esteem between Life Stress and Suicidal Ideation in Nursing College Students)

  • 박필남
    • 한국학교보건학회지
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    • 제29권1호
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    • pp.1-10
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    • 2016
  • Purpose: The purpose of this study was to identify the mediating effect of stress coping type and self-esteem between life stress and suicidal ideation in nursing college students. The research design was descriptive study. Methods: A set of self-reported questionnaires was completed by 197 nursing college students, including demographic characteristics, life stress, stress coping type, self-esteem, and suicidal ideation. Data was analyzed using t-test, ANOVA, $Scheff{\acute{e}}^{\prime}s$ test, correlation analysis, and regression analysis for mediating effect by SPSS ver. 22. Results: The mean age was 20.9 years. The mean scores were 2.4, 3.6, and 1.7 out of 5 Likert scales for items of life stress, self-esteem, and suicidal ideation, respectively. The mean score for stress coping type was 2.36 out of 4 Likert scales. There was a positive correlation between suicidal ideation and life stress related to tasks, life stress related to interpersonal relationship, and emotion-focused coping of stress coping type (r=.537, p<.01); while a negative correlation between self-esteem and suicidal ideation. emotional-focused coping of stress coping type had a partial mediating effect between life stress related to tasks and suicidal ideation. Also, self-esteem had a partial mediating effect between life stress related to tasks and suicidal ideation as well as between life stress related to interpersonal relationship and suicidal ideation. Conclusion: Based on the finding of this study, it is necessary to apply various program to stress coping skill and self-esteem in order to reduce suicidal ideation in nursing college students.

체외순환이 보체활성화화 백혈구의 폐내 정체에 미치는 영향에 관한 연구 (A Study on Effect to Complement Activation and Pulmonary Leukostasis During Cardiopulmonary bypass: Comparison of Bubble Oxygenator and Membrane Oxygenator)

  • 김양원;최석철;조광현
    • Journal of Chest Surgery
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    • 제28권7호
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    • pp.649-657
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    • 1995
  • From December 1993 to April 1994, to investigate complement activation and pulmonary leukostasis, thirty adult patients were studied during cardiopulmonary bypass[CPB for cardiac surgery in Department of Cardiovascular & Thoracic Surgery, Pusan Paik Hospital, Inje University. Total patients were divided into group I and II according to the purpose of study ; Group I was 15 patients undergoing CPB with bubble oxygenator, Group II was 15 patients undergoing CPB with membrane oxygenator. The results of study were summarized as follows.1. The decrease of C3 and C4 levels were observed within few minutes of beginning of CPB in all patients[P<0.05 , and this decrease was proved to be due to complement activation, not by the influence of hemodilution.2. In the correlation between the change of C3 and C4, group I showed linear correlation each other suggesting complement activation occurred through the classical pathway, group II showed a correlation at only partial sampling times suggesting complement activation via both classical and alternative pathway, however there was no significant statistical difference at the change of C3 and C4 concentrations in two groups[P>0.05 .3. After switching to partial CPB, a few difference between right atrial and left atrial WBC count was observed, but statistically not significant and median cell count difference between group I and II was not significant, too [P>0.05 . With the above result, we concluded that CPB itself contributes to the activation of complement system, but bubble oxygenator does not activate always complement system more than membrane oxygenator.

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Relationship between Obesity and Dental Caries in Some University Students: A Pilot Study

  • Hwang, SooJeong;Kim, Hoon;Seo, MinSeock
    • 치위생과학회지
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    • 제21권2호
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    • pp.127-132
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    • 2021
  • Background: Obesity and dental caries have common risk factors such as food intake, eating habits, and lifestyle. Nevertheless, there has been no consensus on the significant association between obesity and dental caries, and additional studies are needed. We investigated the relationship between obesity and dental caries in some college students in this pilot study. Methods: Forty-two obese college students (body mass index [BMI]≥25) registered at a University Obesity Clinic and 19 normal students (18.5≤BMI<25) were recruited. Oral examinations were conducted, and anthropometric data and blood samples were collected. The blood concentrations of low-density lipoprotein (LDL), high-density lipoprotein, and triglyceride were also measured. After controlling for dental plaque index, a univariate analysis of dental caries indicators related to obesity was performed; partial correlation analysis was also conducted. A nonparametric test was used for the analysis of gender-related trends due to the limited number of participants. Results: The obese group had significantly fewer missing teeth (p=0.014), missing surfaces (p=0.035), filled surfaces (p=0.038), and decayed-missing-filled surfaces (p=0.020) than the normal group. There was no difference between the males in the normal and obese groups. The females in the obese group had significantly fewer missing teeth (p=0.003), missing surfaces (p=0.003), and decayed-missing-filled surfaces (p=0.046). Partial correlation analysis showed a weak negative correlation (r=-0.256) between the blood LDL concentration and decayed-missing-filled teeth. The other obesity and dental caries indicators were not correlated. Conclusion:The blood cholesterol concentration had a negative relationship with dental caries, and there were fewer cases of dental caries in the obese group in this study. However, it is important to clarify the relationship between obesity and dental caries through a dietary survey or additional investigations considering other confounding factors.

희박 벡터자기상관회귀 모형을 이용한 한국의 미세먼지 분석 (The sparse vector autoregressive model for PM10 in Korea)

  • 이원석;백창룡
    • Journal of the Korean Data and Information Science Society
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    • 제25권4호
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    • pp.807-817
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    • 2014
  • 본 논문은 최근 많은 관심을 받는 미세먼지 (PM10)의 일별 평균농도에 대해서 전국 16개 시도에서 2008년부터 2011년까지 관측한 다변량 시계열 자료에 대한 연구이다. 다변량 시계열 모형을 이용해서 시간 및 공간에 대한 상관관계를 동시에 고려, 일변량 혹은 특정 지역에 국한해서 분석한 기존의 연구와 차별성을 두었다. 또한 Davis 등 (2013)이 제안한 부분 스펙트럼 일관성 (partial spectral coherence)을 통해 다른 지역간의 상호 의존성을 파악하고 이를 토대로 변수 선택을 통해 희박벡터자기회귀모형 (sVAR; sparse vector autoregressive model)을 적합하는 방법론을 적용하여 고차원 자료 분석의 단점 및 한계를 보완하였으며 예측력 비교를 통해서 sVAR 모형 적합의 타당성을 검증하였다.