Increased blood pressure (BP) variability is associated with the development of target organ damage. However, the optimal type and index of BP variability (BPV) regarding their prognostic ...significance is unclear. The aim of our study was to compare the association of ambulatory and home BPV with the left ventricular mass index (LVMI) in patients with chronic kidney disease (CKD). From a total of 1560 consecutive subjects, 137 hypertensive patients with CKD underwent home and ambulatory BP monitoring and echocardiographic measurements. The variability of home BP monitoring was quantified by using the standard deviation (SD), coefficient of variation (CV), and morning minus evening BP values. Ambulatory BPV was quantified using the SD, CV, and the time rate (TR) of BP variation. The univariate analysis demonstrated that day-to-day systolic SD and the 24-h TR of systolic BP (SBP) variation were significantly associated with the LVMI. The multivariate linear regression analysis showed a significant and independent association of the LVMI with the 24-h TR of SBP variation (B = 9.204, 95% CI: 1.735-16.672; p = 0.016). A 0.1-mmHg/min increase in the 24-h TR of SBP variation was associated with an increment of 9.204 g/m
in the LVMI, even after adjustment for BP and other vascular risk factors. In conclusion, ambulatory BPV but not home BPV was associated with the LVMI in CKD patients. The 24-h TR of SBP variation was the only BPV index associated with the LVMI, independent of average BP values.
Many approaches have been proposed for deriving tests from finite state machine (FSM) specifications with respect to some established coverage criteria. A fundamental core problem in FSM-based ...testing relates to the derivation of input sequences that can distinguish states of an FSM specification, aka distinguishing sequences. A major effort in the construction of these sequences is based on the derivation of a successors search-tree labeled by sets of pairs of states of the given machine. We aim at reducing the time associated with such constructions through the use of state-of-the-art parallel technologies. Namely, we propose a parallel algorithm that we implement and evaluate on multicore CPUs and on many-core GPUs. We evaluate two alternative GPU implementations that use the CUDA and Thrust software platforms and a network of workstations based solution. The latter sports a workload partitioning based on Divisible Load Theory. A rigorous set of experiments highlights the differences of the proposed implementations in terms of execution time and speedup.
We aim at reducing the time associated with the construction of the successors of all state pairs of a given non-deterministic finite state machine. We propose a parallel algorithm that we implement and evaluate on multicore CPUs and on many-core GPUs. We evaluate two alternative GPU implementations that use the CUDA and Thrust software platforms. Additionally, we propose and evaluate a Network of Workstations solution based on Divisible Load Theory. A rigorous set of experiments highlights the differences of the proposed implementations in terms of execution time and speedup.
► Optimized transcoding of both CBR and VBR media on heterogeneous platforms. ► Closed-form solutions for data partitioning problem. ► Theorem establishes the optimum operation sequence for ...single-port setups. ► Extensive experimental results are reported, based on feature-length movies. ► Proposed NPWFVBR method balances execution time and distortion.
Video transcoding is a popular technique for delivering video content of varying quality and size to diverse audiences.
In this paper an analytical approach to the optimization of a large collection of parallel transcoding techniques based on temporal partitioning, is pursued. The key elements in the design of such techniques are identified, allowing them to be enumerated and classified. Closed-form solutions to the partitioning/scheduling problem (and optimum operation sequencing where necessary) are derived for the most important of these methods, under CBR input media conditions. Subsequently, appropriate heuristics allow the solution of the partitioning problem under VBR input media conditions.
The paper is concluded by an extensive battery of tests for the most significant strategies, on several feature-length video streams. The tests reveal not only how one of the proposed strategies, namely NPWFVBR, strikes a nice balance between efficiency and distortion minimization on heterogeneous platforms, but also allow us to derive guidelines for transcoding solution deployment.
OBJECTIVEThe extent of target organ damage has been associated with both central hemodynamics and arterial stiffening, and the time rate of blood pressure (BP) changes in essential hypertension. ...However, the relative significance of these parameters has not been examined.
METHODSWe recruited 232 consecutive uncomplicated newly diagnosed hypertensive patients and 241 normotensive individuals. Twenty-four-hour ambulatory BP monitoring was performed in all individuals. The time rate of SBP variation was computed as the first derivative of the SBP values against time. Aortic central SBP and central DBP, central pulse pressure, central augmentation index and central augmentation pressure were assessed noninvasively by pulse wave analysis. Common carotid artery intima–media thickness was measured by high-resolution ultrasonography.
RESULTSMedian 24-h time rate of BP changes was 0.571 ± 0.114 mmHg/min. Traditional risk factors, office SBP, several ambulatory BP monitoring parameters (24-h SBP, 24-h pulse pressure, 24-h heart rate and BP dipping), 24-h time rate of BP changes, time rate of BP changes at different time intervals, and central SBP, central pulse pressure, central augmentation index and central augmentation pressure significantly correlated with intima–media thickness. Age, sex, BMI, 24-h time rate of BP changes, time rate of BP changes measured at 0100–0600 h and 24-h heart rate remained significant associates of intima–media thickness after adjustment for confounding factors. By multivariate stepwise linear regression, 24-h time rate of BP changes and time rate of BP changes at 0100–0600 h had incremental value over traditional risk factors, other ambulatory BP monitoring parameters and central hemodynamics.
CONCLUSIONThese findings indicate that time rate of BP variation is superior to central hemodynamics as an associate of carotid intima–media thickness in hypertensive and normotensive individuals.
OBJECTIVESBlood pressure (BP) changes are steeper in hypertensive than in normotensive individuals, whereas an increased rate of BP fluctuations is associated with medial hypertrophy of the carotid ...arteries. We evaluated the association between the rate of BP variation derived from ambulatory blood pressure monitoring (ABPM) data analysis and left ventricular mass (LVM).
METHODSABPM and echocardiographic measurements of LVM were performed in 365 normotensive, 185 white-coat hypertensive (WCH) and 448 uncomplicated hypertensive individuals.
RESULTSThe daytime and night-time rate of systolic blood pressure (SBP) and diastolic BP variation were significantly higher in hypertensive than in normotensive (P < 0.001) and WCH (P < 0.05) individuals. In the entire study population multiple linear regression models revealed independent determinants of LVM in the following rank orderbody mass index (β + 0.266, P < 0.001), daytime SBP (β + 0.264, P < 0.001), male sex (β +0.220, P < 0.001), age (β + 0.203, P < 0.001), daytime heart rate (HR; β − 0.191, P < 0.001), daytime rate of SBP variation (β + 0.167, P < 0.001), and SBP dipping (β − 0.132, P < 0.001). A 0.1 mmHg/min increase in the daytime rate of SBP variation correlated with an increment of 7.087 g (95% confidence interval 4.775–9.399) in the LVM. The addition of the daytime rate of SBP variation in the multiple regression model for the prediction of LVM significantly increased the adjusted model R R change 0.024 (2.4%); P for change < 0.001.
CONCLUSIONSteeper BP variations may produce a greater stress on the left ventricular wall and may have an additive role to body habitus, BP and HR levels in the detection of cardiac hypertrophy. Target-organ damage in hypertensive patients, in addition to BP levels, dipping status and BP variability, may also be related to a steeper rate of BP oscillations.
Image-content queries or image registration algorithms typically have very high computational requirements. In this paper, we address the problem of minimizing the total execution time of ...data-parallel image-content query algorithms on heterogeneous platforms. The model we use to capture the inner workings of these algorithms is comprehensive enough to incorporate not only the communication overheads, both distribution and result collection, but also the presence of local data caches that could exist as a result of previous queries. The problem is solved under all possible computation and communication configurations, including single and multiple-port communications and block or stream-type tasks. Our analysis, either, yields closed-form solutions to the partitioning problem, or, formulates the problem in a fashion that allows the use of linear programming tools toward this end. The latter are used for solving the multi-installment data distribution approaches, that tend to utilize the computational resources more efficiently. Additionally, a heuristic algorithm is presented, for producing a close-to-optimum sequence of load distribution/result collection operations for single-port communications. Based on our analytical results, a thorough simulation and experimental study is performed, yielding substantial design guidelines for implementation strategies.
The problem of optimally distributing a divisible load to the nodes of an arbitrary processor tree is tackled in this paper. The rigorous mathematical foundation presented allows the derivation of ...the sequence of operations that is necessary to obtain the minimum processing time, along with closed-form expressions that yield the solution in time O(NP), where P is the number of tree nodes and N their maximum degree. The main contributions of this work are: (1) both load distribution and result collection overheads are considered, thus providing better resource utilization, and (2) arbitrary processor trees are examined in contrast with previous approaches that examined either complete homogeneous trees, or single level trees. Additionally, approximate algorithms for solving the problem of specifying the optimum subset of active processors for a given load, are presented and evaluated.
Several works on multimedia storage appear in literature today, but very little if any, have been devoted to handling long duration video retrieval, over large scale networks. Distributed retrieval ...of multimedia documents, especially the long duration documents, is an imperative step in rendering high-quality, high-fidelity, and cost-effective services for network service providers. Distributed Multimedia Retrieval Strategies for Large Scale Networked Systems presents an up-to-date research status in the domain of distributed video retrieval. This professional book will include several different techniques that are in place for long duration video retrieval. An experimentally tested technology under the JINI platform, demonstrates a practical working system which serves as a feasibility study, as well as the first step in realizing such a technology.
This paper introduces a sign language translation system designed to bridge the communication gap between Hard of Hearing (HOH) or mute individuals, and address challenges in job opportunities and ...mental health. The system offers bi-directional translation of sign language and speech/text. For sign language to speech/text translation, the system utilizes either camera-based gestures, or data-glove inputs. The reverse translation is facilitated through a 3D avatar demonstrating the corresponding sign language for the input speech or text. Our findings demonstrate the system’s translation accuracy and its potential to empower HOH and mute individuals in various communication scenarios.
