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11.
Jen Hong Tan U. Rajendra Acharya Choo Min Lim K. Thomas Abraham 《Digital Signal Processing》2013,23(3):1022-1031
Feasible clinical application of any automated segmenting methodology demands more than just accuracy. Amendment to the automated delineation is necessary when the algorithm fails, however, integrated solution to such a scenario is largely absent in literature. Hence in this survey we devised an architecture that does both the automated and interactive lung field localizations using a single segmenting engine—random walker algorithm—so that intuitive amendment is only necessary when the automated generated delineation is unsatisfactory. The algorithm proceeds by first extracting 18 intensity profiles running horizontally, each of them equally spacing apart, and in each intensity profile three extreme points denoting the two lungs and the esophagus are determined through profile matching. This done, the algorithm removes profiles that do not intersect with the lung, and the rest of the extreme points are plugged into random walker algorithm to perform segmentation. The achieved accuracy in localization by the above was 0.8875 in terms of overlap measure (the maximum value for this parameter is 1) over 341 images. In the case where unsatisfactory delineation prompts amendment necessary, the user can interactively segment the lung by just a shift on some of the previous-determined points to the desired locations, and random walker algorithm is run again with the amended input. By such a fusion, the benefits of both the automated and interactive segmentation are shared in a single architecture. 相似文献
12.
Finding fault elements in linear antenna arrays using bacteria foraging optimization (BFO) is presented. One of the better options of array diagnosis is to perform it by measuring the radiated field, because in this case, removal of the array from its working site is not required and thereby not interrupting its normal operation. This task of fault finding from far‐field data is designed as an optimization problem where the difference between the far‐field power pattern obtained for a given configuration of failed element(s) and the measured one is minimized w. r. t. the excitations of the array elements. This set of excitations on comparison with the excitations of the original array gives the idea of the fault position and their type, such as either complete fault or partial fault. BFO being relatively new to microwave community when compared with other soft‐computing techniques, its performance was observed w. r. t. time of computation and convergence of the iterative process. Possibility of finding the faults from random sample points and use of minimum number of sample points for array fault finding are the novelties of the present work. © 2012 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2013. 相似文献
13.
14.
This paper presents a joint study of application and architecture to improve the performance and scalability of an irregular
application—computing betweenness centrality—on a many-core architecture IBM Cyclops64. The characteristics of unstructured
parallelism, dynamically non-contiguous memory access, and low arithmetic intensity in betweenness centrality pose an obstacle
to an efficient mapping of parallel algorithms on such many-core architectures. By identifying several key architectural features,
we propose and evaluate efficient strategies for achieving scalability on a massive multi-threading many-core architecture.
We demonstrate several optimization strategies including multi-grain parallelism, just-in-time locality with explicit memory
hierarchy and non-preemptive thread execution, and fine-grain data synchronization. Comparing with a conventional parallel
algorithm, we get 4X-50X improvement in performance and 16X improvement in scalability on a 128-cores IBM Cyclops64 simulator. 相似文献
15.
Sreedhar Ganapuram G.T. Vijaya Kumar I.V. Murali Krishna Ercan Kahya M. Cüneyd Demirel 《Advances in Engineering Software》2009,40(7):506-518
The objective of this study is to explore the groundwater availability for agriculture in the Musi basin. Remote sensing data and geographic information system were used to locate potential zones for groundwater in the Musi basin. Various maps (i.e., base, hydrogeomorphological, geological, structural, drainage, slope, land use/land cover and groundwater prospect zones) were prepared using the remote sensing data along with the existing maps. The groundwater availability of the basin is qualitatively classified into different classes (i.e., very good, good, moderate, poor and nil) based on its hydrogeomorphological conditions. The land use/land cover map was prepared for the Kharif season using a digital classification technique with the limited ground truth for mapping irrigated areas in the Musi basin. The alluvial plain in filled valley, flood plain and deeply buried pediplain were successfully delineated and shown as the prospective zones of groundwater. 相似文献
16.
M. P. Mahabole R. C. Aiyer C. V. Ramakrishna B. Sreedhar R. S. Khairnar 《Bulletin of Materials Science》2005,28(6):535-545
Hydroxyapatite (HAp) biomaterial ceramic was synthesized by three different processing routes viz. wet chemical process, microwave
irradiation process, and hydrothermal technique. The synthesized ceramic powders were characterized by SEM, XRD, FTIR and
XPS techniques. The dielectric measurements were carried out as a function of frequency at room temperature and the preliminary
study on CO gas sensing property of hydroxyapatite was investigated. The XRD pattern of the hydroxyapatite biomaterial revealed
that hydroxyapatite ceramic has hexagonal structure. The average crystallite size was found to be in the range 31–54 nm. Absorption
bands corresponding to phosphate and hydroxyl functional groups, which are characteristic of hydroxyapatite, were confirmed
by FTIR. The dielectric constant was found to vary in the range 9–13 at room temperature. Hydroxyapatite can be used as CO
gas sensor at an optimum temperature near 125°C. X-ray photoelectron spectroscopic studies showed the Ca/P ratio of 1.63 for
the HAp sample prepared by chemical process. The microwave irradiation technique yielded calcium rich HAp whereas calcium
deficient HAp was obtained by hydrothermal method. 相似文献
17.
Vaibhav Kulshrestha K. Awasthi N. K. Acharya M. Singh Y. K. Vijay 《Bulletin of Materials Science》2005,28(7):643-646
In the present study the polyethersulphone (PES) membranes of thickness (35 ±2) μm were prepared by solution cast method.
The permeability of these membranes was calculated by varying the temperature and by irradiation of α ions. For the variation
of temperature, the gas permeation cell was dipped in a constant temperature water bath in the temperature range from 303–373
K, which is well below the glass transition temperature (498 K). The permeability of H2 and CO2 increased with increasing temperature. The PES membrane was exposed by a-source (95Am241) of strength (1 μ Ci) in vacuum of the order of 10−6 torr, with fluence 2.7 × 107 ions/cm2. The permeability of H2 and CO2 has been observed for irradiated membrane with increasing etching time. The permeability increases with increasing etching
time for both gases. There was a sudden change in permeability for both the gases when observed at 18 min etching. At this
stage the tracks are visible with optical instrument, which confirms that the pores are generated. Most of pores seen in the
micrograph are circular cross-section ones. 相似文献
18.
Reusability of software, regardless of its utilizing technique, is widely believed to be a promising means for improving software productivity and reliability. However it is not practiced adequately due to the lack of techniques that facilitate the locating of reusable components that are functionally close. In this paper we apply Kohonen's Self-Organizing Maps to develop an approach for promoting Software Reuse. We look at the details of how Self-Organization can arrange and regularize data from the original pattern space into a topology preserving map. We describe a practical implementation of the SOM methodology for Software Reuse using a database of UNIX commands. And finally we briefly present our proposed Software Reuse Methodology. 相似文献
19.
Optimization of process parameters is helpful in efficient working of the process and, hence, in lowering the cost of machining. Optimization of ECM process parameters has been achieved by considering only one objective at a time from metal removal rate, geometrical accuracy, and total process cost. From a practical point of view, a solution of the ecm problem satisfying all three objectives simultaneously is highly desirable.In the proposed model, a multi-objective problem involving the ecm process is formulated producing highly nonlinearized equations. These are then linearized by regression analysis and converted into a goal programming format. Finally, the problem is solved by the partitioning algorithm.It is concluded that the tool, or cathode, remains safe at the optimal values of design variables obtained in the examples discussed. The optimal value of voltage when metal removal rate is the only objective, is found to be higher than the case when the geometrical accuracy requirement is also to be satisfied. 相似文献
20.