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1.
Edge postprocessing using probabilistic relaxation 总被引:2,自引:0,他引:2
Papachristou P. Petrou M. Kittler J. 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2000,30(3):383-402
In this paper, we develop the theory of probabilistic relaxation when the objects to be labeled are arranged in a rectangular grid with known adjacency relations. In this case a dictionary of permissible label configurations is available. The novelty of this work lies in the inclusion of measurements concerning binary relations between the objects to be labeled. These are compared with the corresponding binary relations between the nodes of the dictionary. This way, one of the major objections to probabilistic relaxation, namely, the disregard of the data after the initial assignment of probabilities, is removed. The theory we develop is demonstrated by applying it to the problem of edge relaxation labeling. We show that the inclusion of binary relations greatly improves the performance of algorithms of this kind and compare our approach with previously developed dictionary based approaches, both theoretically and experimentally. Also, a comparison with other edge-postprocessing strategies is provided. 相似文献
2.
Afroditi Kastrenopoulou Kyriakos E. Kypreos Nicholaos I. Papachristou Stavros Georgopoulos Ioulia Mastora Ioanna Papadimitriou-Olivgeri Argyro Spentzopoulou Dragana Nikitovic Vassilios Kontogeorgakos Harry C. Blair Dionysios J. Papachristou 《International journal of molecular sciences》2022,23(9)
In the present study, we studied the effect of apolipoprotein A-1 (APOA1) on the spatial and molecular characteristics of bone marrow adipocytes, using well-characterized ApoA1 knockout mice. APOA1 is a central regulator of high-density lipoprotein cholesterol (HDL-C) metabolism, and thus HDL; our recent work showed that deficiency of APOA1 increases bone marrow adiposity in mice. We found that ApoA1 deficient mice have greatly elevated adipocytes within their bone marrow compared to wild type counterparts. Morphologically, the increased adipocytes were similar to white adipocytes, and displayed proximal tibial-end localization. Marrow adipocytes from wild type mice were significantly fewer and did not display a bone-end distribution pattern. The mRNA levels of the brown/beige adipocyte-specific markers Ucp1, Dio2, Pat2, and Pgc1a; and the expression of leptin were greatly reduced in the ApoA1 knock-out in comparison to the wild-type mice. In the knock-out mice, adiponectin was remarkably elevated. In keeping with the close ties of hematopoietic stem cells and marrow adipocytes, using flow cytometry we found that the elevated adiposity in the ApoA1 knockout mice is associated with a significant reduction in the compartments of hematopoietic stem cells and common myeloid, but not of the common lymphoid, progenitors. Moreover, the ‘beiging’-related marker osteopontin and the angiogenic factor VEGF were also reduced in the ApoA1 knock-out mice, further supporting the notion that APOA1—and most probably HDL-C—regulate bone marrow microenvironment, favoring beige/brown adipocyte characteristics. 相似文献
3.
A method for test synthesis in the behavioral domain is described.The approach is based on the notion of adding a test behavior to the normal-mode design behavior. This testbehavior describes the behavior of the design in test mode. Thenormal-mode design behavior and test-mode test behavior are combinedand then synthesized by any general-purpose synthesis system toproduce a testable design with inserted BIST structures. The testbehavior is derived from the design behavior using testabilityanalysis based on metrics that quantify the testability of signalsand variables embedded within behaviors. The insertion method iscombined with a behavioral test scheme thatintegrates a) the design controller and test controller, b) testingof the entire datapath and controller. Examples show that when thetestability insertion procedure is used to modify a behavior beforesynthesis, the resulting synthesized physical implementation isindeed more easily tested than an implementation synthesized directlyfrom the original behavior. 相似文献
4.
Christos A. Papachristou 《Information Sciences》1977,13(1):51-75
A basic problem in switching theory is the optimal realizations of switching functions in a certain basis and with respect to a certain characteristic measure such as complexity, circuit cost, number of input terminals, delay time. Naturally this problem has received much attention and although a general solution has not been accomplished, many very good results have been obtained.This survey does not attempt to include all the literature concerning this general problem. Some outstanding and basic papers will be reviewed emphasizing ideas, assumptions, results and limitations. A measure of circuit performance, labeled L(n), a characteristic index of the class of n-variable functions, will be defined. This measure is an important tool for understanding the difficulties of the problem and for obtaining most of the results. This survey reviews the most significant literature on problems concerning characteristic measures of switching functions, and in particular, measures of circuit complexity, formula complexity or length, and delay time required to realize switching functions. The asymptotic and finite behavior, the upper and lower bounds, and the order of magnitude of L(n) are included for each particular case. 相似文献
5.
Pagoulatou E Triantaphyllidou IE Vynios DH Papachristou DJ Koletsis E Deligianni D Mavrilas D 《Journal of materials science. Materials in medicine》2012,23(6):1387-1396
To achieve natural scaffolds for tissue engineering applications we decellularized bovine pericardial (BP) tissues according to two different protocols: a novel treatment based on Triton(?) X-100 (12 h, 4 °C) (BP1) and a trypsin/EDTA treatment (37 °C, 48 h) (BP2). Results were compared with commercially available acellular xenogeneic biomaterials, Veritas(?) and Collamed(?). Biomechanical characteristics, high (E(h)) and low (E(l)) modulus of elasticity, of the fresh untreated tissue varied with the anatomical direction (apex to base (T) to transverse (L)) (mean ± SDEV): (41.63 ± 14.65-48.12 ± 10.19 MPa and 0.27 ± 0.05-0.30 ± 0.12 MPa respectively). BP1 had no mechanical effect (44.65 ± 19.73-52.67 ± 7.59 MPa and 0.37 ± 0.14-0.37 ± 0.11 MPa, respectively) but BP2 resulted in significant decrease in E(h) and E(l) (20.96 ± 8.17-36.82 ± 3.23 MPa and 0.20 ± 0.06-0.23 ± 0.06 MPa). Hysteresis ratio (h) varied (19-26 % of the loading energy) independently of anatomical direction. Glycosaminoglycans content was unaffected by BP1, while 22 % of chondroitin/dermatan sulphate and 60 % of hyaluronan were removed after BP2 treatment. Endothelial cell adhesion was achieved after 24 h and 3 days cell culture. 相似文献
6.
Nourani M. Papachristou C.A. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》2002,10(1):30-43
In this paper, we present an accurate delay-estimation algorithm at the register-transfer level. We study three important sources of false paths in register-transfer-level (RTL) structures, i.e., 1) resource binding; 2) interdependent conditions; and 3) datapath-controller path mismatching. The existence and creation of such paths and their effects in delay analysis are discussed. We show that in a RTL datapath structure the accuracy of the delay estimators is affected by the existence of false paths. Specifically, the accuracy drops significantly for structures synthesized from condition-dominated behaviors. We propose a mechanism to efficiently avoid false paths in delay analysis. This is achieved by introducing the propagation delay graph (PDG), whose traversal for delay analysis is equivalent to the traversal of sensitizable paths in the datapath. Comparison with the timing verifier in commercial computer-aided design (CAD) tools, show that estimated delays are within 14% accuracy of those reported by CAD tools 相似文献
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8.
G Papachristou A Tilentzoglou N Efstathopoulos L Khaldi 《Canadian Metallurgical Quarterly》1998,6(4):246-252
BACKGROUND: Mepartricin, a semisynthetic polyene derivative with a favorable effect on urethro-prostatic function, was clinically evaluated, adopting the diagnostic and research criteria recommended by the First International Consultation on BPH. METHODS: A multicenter, randomized, double-blind, parallel-group study compared mepartricin 40 mg/daily to placebo in the treatment of 196 patients with newly diagnosed BPH and mild-to-moderate symptomatology. International Prostate Symptom Score (I-PSS), quality of life (QoL) index and maximum urinary flow-rate (Qmax) were determined every 4 weeks for 6 months; postvoiding volume, prostate volume, and prostate-specific antigen (PSA) were assessed after 3 and 6 months of therapy. RESULTS: Mepartricin was shown to determine a statistically significant improvement over placebo in I-PSS and QoL index from month 2 onwards, and a significant linear increase in Qmax over the study period. At month 6, the improvement in the mepartricin and placebo groups in I-PSS, QoL index, and Qmax was 6.3 (standard error (SE) 0.51) and 4.2 (SE 0.60) points (P = 0.003), 0.99 (SE 0.14) and 0.62 (SE 0.12) points (P = 0.036), and 2.7 (SE 0.46) and 1.2 (SE 0.46) ml/sec (P = 0.051), respectively. No significant differences were noted in postvoiding residual volume, prostate volume, or PSA. Mepartricin tolerability was good, showing no adverse events on sexual function. CONCLUSIONS: Mepartricin proved to be an effective treatment of benign prostatic hyperplasia, determining an improvement in symptoms, quality of life, and peak urinary flow. 相似文献
9.
The CSMA/CA algorithm proposed in the IEEE 802.11 standard does not exclude collisions between transmitted packets. Regardless of whether RTS/CTS packets are used or not, these collisions do always have a more or less negative effect on system performance, especially at high loads. In this letter a method of avoiding collisions by using busy energy bursts is proposed. The algorithm used is based on the 802.11 standard and depends only on the assumption that each node can hear the transmissions of all other nodes. Collisions are avoided by transmitting short sequences of energy bursts without the need of any further communication between nodes contending for the use of the channel. The proposed method provides better average packet delays also as higher maximum system loads than conventional CSMA/CA. In addition to this, it renders the use of acknowledgment packets unnecessary. 相似文献
10.
Experimental studies have been made on the fault coverage of pattern-sensitive fault-detection algorithms proposed for semiconductor memories. The experiment is carried out on a microprocessor-based system. A comparative study has been made based on the experimental results. 相似文献