• Title/Summary/Keyword: difference matrix

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BOUNDEDNESS OF DISCRETE VOLTERRA SYSTEMS

  • Choi, Sung-Kyu;Goo, Yoon-Hoe;Koo, Nam-Jip
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.4
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    • pp.663-675
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    • 2007
  • We investigate the representation of the solution of discrete linear Volterra difference systems by means of the resolvent matrix and fundamental matrix, respectively, and then study the boundedness of the solutions of discrete Volterra systems by improving the assumptions and the proofs of Medina#s results in [6].

ON A CERTAIN FINITE DIFFERENCE SCHEME FOR A MODEL FOR DIFFUSION OF BIOLOGICAL POPULATIONS

  • Asghar, Kerayechian
    • Journal of applied mathematics & informatics
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    • v.6 no.2
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    • pp.455-466
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    • 1999
  • In this note we present a numerical scheme for finding an approxximate solution of an equation which can be viewed as a model for spatial diffusion of age-depednent biological populations. Discretization of the model yields a linear system with a block tridi-agonal matrix. Our main concern will be discussion of stability for this scheme by examining the eigenvalues of the block tridiagonal matrix. Numerical results are presented.

h-STABILITY IN VOLTERRA DIFFERENCE SYSTEMS

  • Goo, Yoon Hoe;Park, Gyeong In;Ko, Jung Hyun
    • Journal of the Chungcheong Mathematical Society
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    • v.22 no.3
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    • pp.535-543
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    • 2009
  • We investigate h-stability of solutions of nonlinear Volterra difference systems and linear Volterra difference systems.

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Analysis on the Quench Characteristics According to Magnetic Field of the Matrix-Type SFCL with $1{\times}3$ Matrix Structure ($1{\times}3$ 행렬구조를 갖는 매트릭스형 초전도 한류기의 자장유무에 따른 퀜치특성 분석)

  • Oh, Kum-Gom;Cho, Yong-Sun;Choi, Hyo-Sang
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.57 no.3
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    • pp.343-348
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    • 2008
  • We investigated the quench characteristics accordance with increase of turns and applied voltage of matrix-type superconducting fault current limiter (SFCL) with $1{\times}3$ matrixes. The matrix-type SFCL consists of the trigger part to apply magnetic field and the current-limiting part to limit fault current. The fault current limiting characteristics according to the increase of magnetic field and applied voltage were nearly same. This is because the application of magnetic field has not an affect on total impedance of SFCL. When number of turns of reactor increased, the voltage difference between two superconducting units in the current-limiting part according was decreased. The resistance difference generated in two superconducting units also was decreased. Therefore, we confirmed that the differences of critical behaviors between superconducting units by application of magnetic field were decreased. By this results, we could be decided the optimum number of turns of reactor to apply magnetic field.

Comparison of Activity Capacity Change and GFR Value Change According to Matrix Size during 99mTc-DTPA Renal Dynamic Scan (99mTc-DTPA 신장 동적 검사(Renal Dynamic Scan) 시 동위원소 용량 변화와 Matrix Size 변경에 따른 사구체 여과율(Glomerular Filtration Rate, GFR) 수치 변화 비교)

  • Kim, Hyeon;Do, Yong-Ho;Kim, Jae-Il;Choi, Hyeon-Jun;Woo, Jae-Ryong;Bak, Chan-Rok;Ha, Tae-Hwan
    • The Korean Journal of Nuclear Medicine Technology
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    • v.24 no.1
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    • pp.27-32
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    • 2020
  • Purpose Glomerular Filtration Rate(GFR) is an important indicator for evaluating renal function and monitoring the progress of renal disease. Currently, the method of measuring GFR in clinical trials by using serum creatinine value and 99mTc-DTPA(diethylenetriamine pentaacetic acid) renal dynamic scan is still useful. After the Gates method of formula was announced, when 99mTc-DTPA Renal dynamic scan is taken, it is applied the GFR is measured using a gamma camera. The purpose of this paper is to measure the GFR by applying the Gates method of formula. It is according to effect activity and matrix size that is related in the GFR. Materials and Methods Data from 5 adult patients (patient age = 62 ± 5, 3 males, 2 females) who had been examined 99mTc-DTPA Renal dynamic scan were analyzed. A dynamic image was obtained for 21 minutes after instantaneous injection of 99mTc-DTPA 15 mCi into the patient's vein. To evaluate the glomerular filtration rate according to changes in activity and matrix size, total counts were measured after setting regions of interest in both kidneys and tissues in 2-3 minutes. The distance from detector to the table was maintained at 30cm, and the capacity of the pre-syringe (PR) was set to 15, 20, 25, 30 mCi, and each the capacity of post-syringe (PO) was 1, 5, 10, 15 mCi is set to evaluate the activity change. And then, each matrix size was changed to 32 × 32, 64 × 64, 128 × 128, 256 × 256, 512 × 512, and 1024 × 1024 to compare and to evaluate the values. Results As the activity increased in matrix size, the difference in GFR gradually decreased from 52.95% at the maximum to 16.67% at the minimum. The GFR value according to the change of matrix size was similar to 2.4%, 0.2%, 0.2% of difference when changing from 128 to 256, 256 to 512, and 512 to 1024, but 54.3% of difference when changing from 32 to 64 and 39.43% of difference when changing from 64 to 128. Finally, based on the presently used protocol, 256 × 256, PR 15 mCi and PO 1 mCi, the GFR value was the largest difference with 82% in PR 15 mCi and PO 1 mCi. conditions, and at the least difference is 0.2% in the conditions of PR 30 mCi and PO 15 mCi. Conclusion Through this paper, it was confirmed that when measuring the GFR using the gate method in the 99mTc-DTPA renal dynamic scan. The GFR was affected by activity and matrix size changes. Therefore, it is considered that when taking the 99mTc-DTPA renal dynamic scan, is should be careful by applying appropriate parameters when calculating GFR in the every hospital.

Analysis of Spatial Information Characteristics for Establishing Land Use, Land-Use Change and Forestry Matrix (Land Use, Land-Use Change and Forestry 매트릭스 작성을 위한 공간정보 특성 고찰)

  • HWANG, Jin-Hoo;JANG, Rae-Ik;JEON, Seong-Woo
    • Journal of the Korean Association of Geographic Information Studies
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    • v.21 no.2
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    • pp.44-55
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    • 2018
  • The importance of establishing a greenhouse gas inventory is emerging for policymaking and its implementation to cope with climate change. Thus, it is needed to establish Approach 3 level Land Use, Land-Use Change and Forestry (LULUCF) matrix that is spatially explicit regarding land use classifications and changes. In this study, four types of spatial information suitable for establishing the LULUCF matrix were analyzed - Cadastral Map, Land Cover Map, Forest Map, and Biotope Map. This research analyzed the classification properties of each type of spatial information and compared the quantitative and qualitative characteristics of the maps in Boryeong city. Drawn from the conclusions of the quantitative comparison, the forest area showed the maximum difference of 50.42% ($303.79km^2$) in the forest map and 46.09%($276.65km^2$) in the cadastral map. The qualitative comparison drew five qualitative characteristics: data construction scope difference, data construction purpose difference, classification standard difference, and classification item difference. As a result of the study, it was evident that the biotope map was the most appropriate spatial information for the establishment of the LULUCF matrix. In addition, if the LULUCF matrix is made by integrating the biotope, the forest map, and the land cover map, the limitations of each spatial information would be improved. The accuracy of the LULUCF matrix is expected to be improved when the map of the level-3 land cover map and the biotope map of 1:5,000 covering the whole country are completed.

Morphological Assessment of Proximal Restoration Depending on Different Matrix Systems in Primary Molars with a 3D Scanner: In Vitro Studies (매트릭스 시스템에 따른 유구치 인접면 수복물에 대한 3D 스캐너를 이용한 형태학적 평가: 실험실적 연구)

  • Hyewon Shin;Nanyoung Lee;Joohun Song;JoonSeong Kim;Myeongkwan Jih
    • Journal of the korean academy of Pediatric Dentistry
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    • v.50 no.4
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    • pp.396-408
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    • 2023
  • The purpose of this study was to compare the proximal surface contour, size of contact area, and volume difference before and after restoration in artificial teeth of primary molars during proximal composite resin restoration using different matrix systems. Four types of artificial teeth were restored with composite resin using sectional matrix systems-Palodent V3 Sectional Matrix System and myJunior Kitand a circumferential matrix system-Tofflemire Matrix System-and modeled threedimensionally for analysis. When sectional matrix systems were used, there was a higher probability of concave proximal surface contour and simultaneously greater contact area and volume. This is attributed to the dead soft properties of the matrix band used in sectional matrix systems, which can lead to deformation of the band and hence an excessive amount of resin applied around the contact point. Additionally, the rubber wedge in the sectional matrix system may not help the matrix band fit into the cavity. Therefore, based on the findings of this study, morphological aspects need to be carefully considered for proximal composite resin restoration of primary molars using sectional matrix systems.

An elasto-plastic solution for infinite solid containing a spherical precipitate under hydrostatic pressure (구형석출물을 갖는 무한 고체에 전수압이 가해지는 경우에 대한 탄소성해)

  • ;;Earmme, Youn Young
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.5 no.2
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    • pp.122-130
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    • 1981
  • Equation of equilibrium is derived and solved for an infinite isotropic solid under applied hydrostatic stress which is uniform at large distance, and disturbed by a spherical precipitate which has isotropoc elastic constants dirrerent form those of the matrix. A linear strain hardening behavior of the matrix is assumed, and an elasto-plastic sloution is obtained. The difference of the total strain energy stored inthe infinite solid with and without a precipitate is computed, and compared with that for purely elastic case. Finally the effect of the ratio of the bulk modulus of the precipitate to that of the matrix and the effct of linear strain hardening rate on the plastic zone size and the energy difference are discussed.

Miniaturized Development of Microwave Power Divider Using High-Tc Superconductors (고온초전도체를 이용한 마이크로파 전력분배기의 소형화 개발)

  • Chung, Dong-Chul;Yoo, Byung-Hwa;Kwak, Min-Hwan;Kang, Gwang-Yong;Han, Byoung-Sung
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.58 no.3
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    • pp.334-338
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    • 2009
  • In this paper, We report the miniaturization of superconducting microwave power dividers based on lumped element equivalent circuits. To do this, we analyzed a conventional branch-type power divider by using an ABCD matrix under even and odd mode excitation. Then, we calculated each lumped element impedance throughout this analysis of a transmission line matrix. Also we simulated our equivalent circuits made of lumped elements by using a full wave analysis, em Sonnet. Our deign of microwave power divider based on simulated results was fabricated on high-$T_c$ superconducting thin films deposited on MgO substrate. Experimental results were reported in terms of bandwidth, center frequency, and phase difference between $S_{21}$ and $S_{31}$. We confirm that our design will be useful in the future microwave power systum.

ON A GENERALIZED DIFFERENCE SEQUENCE SPACES OVER NON-ARCHIMEDIAN FIELDS AND RELATED MATRIX TRANSFORMATIONS

  • BATAINEH AHMAD H. A.;AL-ZA'AREER HAMZA B.
    • Communications of the Korean Mathematical Society
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    • v.20 no.4
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    • pp.723-729
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    • 2005
  • Let F be a non-trivial non-Archimedian field. The sequence spaces $\Gamma\;(F)\;and\;{\Gamma}^{\ast}(F)$ were defined and studied by Soma-sundaram[4], where these spaces denote the spaces of entire and analytic sequences defined over F, respectively. In 1997, these spaces were generalized by Mursaleen and Qamaruddin[1] by considering an arbitrary sequence $U\;=\;(U_k),\;U_k\;{\neq}\;0 \;(\;k\;=\;1,2,3,{\cdots})$. They characterized some classes of infinite matrices considering these new classes of sequences. In this paper, we further generalize the above mentioned spaces and define the spaces $\Gamma(u,\;F,\;{\Delta}),\;{\Gamma}^{\ast}(u,\;F,\;{\Delta}),\;l_p(u,\;F,\;{\Delta})$), and $b_v(u,\;F,\;{\Delta}$). We also study some matrix transformations on these new spaces.