• Title/Summary/Keyword: correlation length

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Fetal heart rate estimation using high resolution pitch detection algorithm (피치 검출 방법을 이용한 태아심음주기의 추출에 관한 연구)

  • Lee, Eung-Goo;Lee, Yong-Hee;Kim, Sun-I.;Lee, Doo-Soo
    • Proceedings of the KOSOMBE Conference
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    • v.1993 no.05
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    • pp.81-85
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    • 1993
  • Despite the simplicity of processing, conventional autocorrelation function (ACF) method for the precise determination of fetal heart rate (FHR) has many problems. In the case of weak or noise corrupted Doppler ultrasound singnals, the ACF method is very sensitive to the threshold level and data window length. It is real troublesome to extract FHR when there is a data loss. To overcome these problems, the high resolution pitch detection algorithm is adapted to estimate the FHR. The FHR is determined from the correlation of two interconnected segments by its maximum correlation value. FHR is compensated with a constant correlation threshold in a greatly smeared noise signal. This method yields more accurate, robust and reliable than the ACF method.

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NEW FAMILY OF BINARY SEQUENCES WITH FOUR-VALUED CROSS-CORRELATION

  • Kim, Han-Doo;Cho, Sung-Jin;Kwon, Min-Jeong;Choi, Un-Sook
    • East Asian mathematical journal
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    • v.29 no.5
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    • pp.529-536
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    • 2013
  • In this paper, we find the values and the number of occurrences of each value of the cross-correlation function $C_d({\tau})$ when $d=\frac{2^{k-1}}{2^s-1}(2^{k(i+1)}-2^{ki}+2^{s+1}-2^k-1)$, where n = 2k, s is an integer such that 2s divides k, and i is odd.

A STUDY OF CORRELATION ON THE SKELETAL FACTORS OF THE ANTERIOR OPEN BITE (전치부 개방교합의 골격요소간 상호연관성에 관한 연구)

  • Kim, Hyung-Il
    • The korean journal of orthodontics
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    • v.15 no.2
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    • pp.249-259
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    • 1985
  • To analyze the skeletal characteristics of the open bite, the faces of normal occlusion and open bite were measured using a cephalogram. The factors which were greatly different from normal occlusion were selected. The effects of these factors on the incisal overbite and correlation on these factors were studied. The following results were obtained: 1. The 13 factors which comprised the characteristics of the open bite were obtained. (Table 5) 2. The cause and amount of the open bite were dependent on the skeletal angulation than skeletal length. 3. For determining the incisal overbite, most highly correlated single factor was the interincisal angle. 4. The correlation on the selected 13 factors which comprised the characteristics of the open bite was obtained. (Table 6) 5. The open bite was due to combination of various factors than due to single factor. (Table 3,4).

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An Experimental Study on Heat Transfer Characteristics Just Before Critical Heat Flux in Uniformly Heated Vertical Annulus Under a Wide Range of Pressures

  • Chun, Se-Young;Moon, Sang-Ki;Chung, Heung-June;Chung, Moon-Ki
    • Nuclear Engineering and Technology
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    • v.34 no.4
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    • pp.269-285
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    • 2002
  • Water heat transfer experiments were carried out in a uniformly heated annulus with a wide range of pressure conditions. The local heat transfer coefficients for saturated water (low boiling have been measured just before the occurrence of the critical heat flux (CHF) along the length of the heated section. The trends of the measured heat transfer coefficients were quite different from the conventional understanding for the heat transfer of saturated flow boiling. This discrepancy was explained from the nucleate boiling in the liquid film of annular flow under high heat flux conditions. The well-known correlations were compared with the measured heat transfer coefficients. The Shah and Kandlikar correlations gave better prediction than the Chen correlation. However, the modified Chen correlation proposed in the present work showed the best agreement with the present data among correlations examined .

Real-Time Camera Tracking for Markerless Augmented Reality (마커 없는 증강현실을 위한 실시간 카메라 추적)

  • Oh, Ju-Hyun;Sohn, Kwang-Hoon
    • Journal of Broadcast Engineering
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    • v.16 no.4
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    • pp.614-623
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    • 2011
  • We propose a real-time tracking algorithm for an augmented reality (AR) system for TV broadcasting. The tracking is initialized by detecting the object with the SURF algorithm. A multi-scale approach is used for the stable real-time camera tracking. Normalized cross correlation (NCC) is used to find the patch correspondences, to cope with the unknown and changing lighting condition. Since a zooming camera is used, the focal length should be estimated online. Experimental results show that the focal length of the camera is properly estimated with the proposed online calibration procedure.

Investigating the Global Financial Markets from a Social Network Analysis Perspective (소셜네트워크분석 접근법을 활용한 글로벌 금융시장 네트워크 분석)

  • Kim, Dae-Sik;Kwahk, Kee-Young
    • Journal of the Korean Operations Research and Management Science Society
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    • v.38 no.4
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    • pp.11-33
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    • 2013
  • We analyzed the structures and properties of the global financial market networks using social network analysis approach. The Minimum Spanning Tree (MST) lengths and networks of the global financial markets based on the correlation coefficients have been analyzed. Firstly, similar to the previous studies on the global stock indices using MST length, the diversification effects in the global multi-asset portfolio can disappear during the crisis as the correlations among the asset class and within the asset class increase due to the system risks. Second, through the network visualization, we found the clustering of the asset class in the global financial markets network, which confirms the possible diversification effect in the global multi-asset portfolio. Meanwhile, we found the changes in the structure of the network during the crisis. For the last one, in terms of the degree centrality, the stock indices were the most influential to other assets in the global financial markets network, while in terms of the betweenness centrality, Gold, Silver and AUD. In the practical perspective, we propose the methods such as MST length and network visualization to monitor the change of the correlation risk for the risk management of the multi-asset portfolio.

Variations in Karyotypic Characteristics of Different Breed Groups of Water Buffaloes (Bubalus bubalis)

  • Bondoc, O.L.;Flor, M.C.G.T.;Rebollos, S.D.N.;Albarace, A.G.
    • Asian-Australasian Journal of Animal Sciences
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    • v.15 no.3
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    • pp.321-325
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    • 2002
  • Karyotype analysis was carried out on blood samples of 30 water buffaloes belonging to different breed groups (i.e. Philippine Carabao (PC), Indian Murrah (IM), Bulgarian Murrah (BM), "$F_1$ 50% IM-50% PC", "$F_1$ 50% BM-50% PC" and "75% IM-25% PC"), using the modified Leucocyte Culture Technique. The modal chromosome numbers of the PC, "$F_1$ 50% IM-50% PC", "$F_1$ 50% BM-50% PC", IM, BM and "75% IM-25% PC" were 2n=48, 49, 49, 50, 50 and 50, respectively. The water buffalo chromosomes are mostly acrocentric (79.67%) and the remainder submetacentric (20.33%). Results of the ordinary least square analysis showed significant breed effects (p<0.01) on other karyotypic characteristics (i.e. relative length, arm ratio and centromeric index). Significant correlation between karyotypic characteristics and some animal performance traits were also found. The significant correlation values imply that karyotypic characteristics can be used as important criteria to select potentially productive young water buffaloes. In the future, more production and reproduction traits from non-institutional herds should be included in the analysis to reveal meaningful correlations with various karyotypic characteristics.

Implementation of the Ultrasonic Local Positioning System using Dual Frequencies and Codes (이중 주파수와 코드를 이용한 초음파 위치 인식 시스템 구현)

  • Cho, Bong-Su;Cho, Seck-Bin;Yang, Sung-Oh;Baek, Kwang-Ryul;Lee, Dong-Hwal
    • Journal of Institute of Control, Robotics and Systems
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    • v.14 no.7
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    • pp.647-655
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    • 2008
  • This paper presents real-time algorithm for an ultrasonic Local Positioning System(LPS). An ultrasonic LPS consists of 4 transmitters and n receivers. Each transmitter transmits an sequential ultrasonic signal to avoid interference of ultrasonic signal. This method is a noneffective application for a fast object. Because receiver detects four sequential transmissive ultrasonic signal and calculates a position. This paper proposes the method which 4 transmitters transmit simultaneous ultrasonic signal and each transmitter distinguished by frequencies and codes. And Auto-Correlation Function(ACF) method separates codes from an ultrasonic echo signal which is interference of each transmitter's code. If the receiver uses only ACF method, it is difficult to implement real time application for increased computation. This paper implements LPS using dual frequencies and ACF method. Using dual frequencies reduces codes length. The reduced codes length save computation in ACF. To prove this algorithm by experiment, high performance DSP(digital signal processor) used. The result shows the performance of the designed system is good enough positioning.

The Comparison of PTT and Systolic Blood Pressure in a hemorrhaged Rat (출혈을 일으킨 흰쥐에서의 PTT와 수축기 혈압 비교)

  • Shim, Young-Woo;Lee, Ju-Hyung;Yang, Dong-In;Kim, Deok-Won
    • Proceedings of the IEEK Conference
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    • 2009.05a
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    • pp.138-140
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    • 2009
  • Hemorrhage shock occupies high rate in trauma patient's mortality and blood pressure is the variance that judges early diagnosis and the effect of remedy. Systolic blood pressure is related to pulse transit time(PTT). PTT means the time that is required to flow from the heart to peripheral artery. PTT is influenced from the length, cross section and stiffness of the blood vessels. It is hard to evaluate the correlation between systolic blood pressure and PTT because they are variable in human body. In this paper, we evaluated the correlation between the systolic blood pressure and PTT in normal and hemorrhage states using standardized rat. PTT is defined as the time differences between the R peak and the peak of pulse wave. The analyzed time differences of ECG and blood pressure are analyzed every 5minutes for 30 seconds when there is before and after bleeding. Before bleeding, systolic blood pressure and PTT are steadily preserved but when the bleeding comes started, systolic blood pressure is declined. However PTT was increased and decreased. Under the circumstance that the standardized rat is controlled by age, the length of the blood vessels, and any disease, it shows that PTT measurement using systolic blood pressure of bleeding is impossible.

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Comparison of Two Nondestructive Methods of Leaf Area Estimation

  • Woo, Hyo-Jin;Park, Yong-Mok
    • Journal of Ecology and Environment
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    • v.32 no.1
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    • pp.61-65
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    • 2009
  • We compared two nondestructive methods for leaf area estimation using leaves of 16 common plant species classified into six types depending on leaf shape. Relatively good linear relationships between actual leaf area (LA) and leaf length (L), width (W), or the product of length and width (LW) were found for ordinary leaves with lanceolate, oblanceolate, linear and sagitttate shapes with entire margins, serrate margins, mixed margins with a entire form and shallow lobes, and ordinary incised margins. LA was better correlated with LW than L or W, with $R^2$ > 0.91. However, for deeply incised lobes, LA estimation using LW showed low correlation coefficient values, indicating low accuracy. On the other hand, a method using photographic paper showed a good correlation between estimates of area based on the mass of a cut-out leaf image on a photographic sheet (PW) and actual leaf area for all types of leaf shape. Thus, the PW method for LA estimation can be applied to all shapes of leaf with high accuracy. The PW method takes a little more time and has a higher cost than leaf estimation methods using LW based on leaf dimensions. These results indicate that researchers should choose their nondestructive LA estimation method according to their research goals.