检索结果-内蒙古大学图书馆

Comparative study on threshold selection for measuring characteristics of turbulent swirling flames in a miniature-scale swirl burner

引用

SIGNAL IMAGE AND VIDEO PROCESSING 2023年第4期17卷 1365-1373页

作者： Sheykhbaglou, Soroush Karami, Shayan Amirkabir Univ Technol Sch Mech Aerosp & Maritime Engn 350 Hafez Ave Tehran Iran Amirkabir Univ Technol Sch Elect Comp & Biomed Engn 350 Hafez Ave Tehran Iran

This study analyzes six threshold approaches for measuring swirling flame properties including flame length, lift-off height, maximum width, area, and flame pulsating displacements in terms of flame center of gravity, length, and width under three operating conditions. Flame video images are captured with the use of a high-speed camera for this objective. The image processing of frames obtained from a high-speed video was fulfilled by utilizing the intermittency distribution approach in order to compare the flame properties quantitatively. The findings show that the Huang technique binarizes the experimental images of the swirling flames the best of the six threshold methods, whereas the Minimum approach produces a large error in flame morphology prediction. After the Huang algorithm, the Yen and Renyi's Entropy-based algorithms do well in forecasting flame morphology, respectively. When compared to the Huang algorithm, the Minimum technique reduces the flame length, maximum width, and area by approximately 34, 26, and 56% for fuel and airflow rates of 0.200 and 3 slpm, respectively. The two approaches of Otsu and Intermodes, on the other hand, yield almost identical flame characteristics. In addition, flame pulsating displacements in terms of center of gravity, length, and width exhibit linear dependency on the fuel flow rate (positive slope), and at a fixed fuel flow rate, pulsating displacement in terms of flame length is larger than pulsating displacement in terms of flame width. In addition, flame pulsating displacement in terms of center of gravity shows the least sensitivity to the fuel flow rate.

关键词： Miniature-scale burner Swirling flame Flame length threshold algorithm Otsu algorithm Huang algorithm Intermittency distribution Flame existence probability Flame pulsating displacement

来源：评论

学校读者我要写书评

暂无评论

threshold protocol for the exchange of confidential medical data

引用

BMC Medical Research Methodology 2002年第1期2卷 1-6页

作者： Berman, Jules J. Cancer Diagnosis Program National Cancer Institute Bethesda MD United States

Background: Medical researchers often need to share clinical data without violating patient confidentiality. threshold cryptographic protocols divide messages into multiple pieces, no single piece containing information that can reconstruct the original message. The author describes and implements a novel threshold protocol that can be used to search, annotate or transform confidential data without breaching patient confidentiality. Methods: The basic threshold protocol is: 1) Text is divided into short phrases;2) Each phrase is converted by a one-way hash algorithm into a seemingly-random set of characters;3) threshold Piece 1 is composed of the list of all phrases, with each phrase followed by its one-way hash;4) threshold Piece 2 is composed of the text with all phrases replaced by their one-way hash values, and with high-frequency words preserved. Neither Piece 1 nor Piece 2 contains information linking patients to their records. The original text can be re-constructed from Piece 1 and Piece 2. Results: The threshold algorithm produces two files (threshold pieces). In typical usage, Piece 2 is held by the data owner, and Piece 1 is freely distributed. Piece 1 can be annotated and returned to the owner of the original data to enhance the complete data set. Collections of Piece 1 files can be merged and distributed without identifying patient records. Variations of the threshold protocol are described. The author's Perl implementation is freely available. Conclusions: threshold files are safe in the sense that they are de-identified and can be used for research purposes. The threshold protocol is particularly useful when the receiver of the threshold file needs to obtain certain concepts or data-types found in the original data, but does not need to fully understand the original data set.

关键词： Original Text Unify Medical Language System Confidential Information threshold algorithm Negotiation Protocol

来源：评论

学校读者我要写书评

暂无评论

An Improved threshold Method based on Histogram Entropy for the Blood Vessel Segmentation

An Improved Threshold Method based on Histogram Entropy for ...

引用

IEEE International Conference on Cyborg and Bionic Systems (CBS)

作者： Guo, Shuxiang Yang, Qiuxia Gao, Baofeng Cai, Xiaojuan Zhao, Yan Xiao, Nan He, Yanlin Zhang, Chaonan Beijing Inst Technol Sch Life Sci Minist Ind & Informat Technol Key Lab Convergence Biomed Engn Syst & Healthcare 5 Zhongguancun South St Beijing 100081 Peoples R China Kagawa Univ Fac Engn 2217-20 Hayashi Cho Takamatsu Kagawa 7608521 Japan

ISBN: (纸本)9781538631942

Interest is growing in the interventional surgery training system used before the treatment of vessel diseases. As one of the elementary component of the simulator, an accurate reconstruction of blood vessel obtaining from cross-sectional images is ugly needed. Digital Subtraction Angiography (DSA) data is used as a criterion for reconstruction result of blood vessel. In this paper, an improved threshold method is proposed to segment blood vessel from medical images. Firstly, with optimization characteristic, the genetic algorithm is used to determine the pre-segmentation greyscale from best histogram entropy. Secondly, we enlarge greyscale around the best greyscale to adjust image intensity value which can greatly singularize the region of interest. And then, classical threshold method (Otsu algorithm) is used to determine the best threshold value which can separate blood vessel from background. To test the improved method, comparative trial was set to testify the improvement. Finally, a series of DSA images were obtained to demonstrate this method and the final experimental results showed the effectiveness of the improved method.

关键词： threshold algorithm Best Histogram Entropy Genetic algorithm Image Intensity Blood Vessel Segmentation

来源：评论

学校读者我要写书评

暂无评论

Efficient processing of exact top-k queries over disk-resident sorted lists

引用

VLDB JOURNAL 2010年第3期19卷 437-456页

作者： Pang, HweeHwa Ding, Xuhua Zheng, Baihua Singapore Management Univ Sch Informat Syst Singapore Singapore

The top-k query is employed in a wide range of applications to generate a ranked list of data that have the highest aggregate scores over certain attributes. As the pool of attributes for selection by individual queries may be large, the data are indexed with per-attribute sorted lists, and a threshold algorithm (TA) is applied on the lists involved in each query. The TA executes in two phases-find a cut-off threshold for the top-k result scores, then evaluate all the records that could score above the threshold. In this paper, we focus on exact top-k queries that involve monotonic linear scoring functions over disk-resident sorted lists. We introduce a model for estimating the depths to which each sorted list needs to be processed in the two phases, so that (most of) the required records can be fetched efficiently through sequential or batched I/Os. We also devise a mechanism to quickly rank the data that qualify for the query answer and to eliminate those that do not, in order to reduce the computation demand of the query processor. Extensive experiments with four different datasets confirm that our schemes achieve substantial performance speed-up of between two times and two orders of magnitude over existing TAs, at the expense of a memory overhead of 4.8 bits per attribute value. Moreover, our scheme is robust to different data distributions and query characteristics.

关键词： Top-k query processing threshold algorithm Bloom filter

来源：评论

学校读者我要写书评

暂无评论

AN EFFICIENT algorithm FOR THE BIPARTITE MATCHING PROBLEM

引用

EUROPEAN JOURNAL OF OPERATIONAL RESEARCH 1986年第1期23卷 86-93页

作者： CARRARESI, P SODINI, C UNIV PISA IST MATEMAT FINANZIARIAI-56100 PISAITALY

The minimum cost bipartite matching problem is considered. An approach based on the solution of a sequence of shortest path sub-problems is proposed. The particular structure of the problem and the use of reduced costs make it possible to devise an efficient 'threshold' algorithm to solve these sub-problems. The computational behaviour of the proposed procedure is analyzed. [ABSTRACT FROM AUTHOR]

关键词： Bipartite matching reduced costs shortest path threshold algorithm

来源：评论

学校读者我要写书评

暂无评论

Representation of the non-dominated set in biobjective discrete optimization

引用

COMPUTERS & OPERATIONS RESEARCH 2015年第Nov.期63卷 172-186页

作者： Vaz, Daniel Paquete, Luis Fonseca, Carlos M. Klamroth, Kathrin Stiglmayr, Michael Max Planck Inst Informat D-66123 Saarbrucken Germany Univ Coimbra Dept Informat Engn CISUC P-3000 Coimbra Portugal Univ Wuppertal Dept Math & Nat Sci Wuppertal Germany

This paper introduces several algorithms for finding a representative subset of the non-dominated point set of a biobjective discrete optimization problem with respect to uniformity, coverage and the epsilon-indicator. We consider the representation problem itself as multiobjective, trying to find a good compromise between these quality measures. These representation problems are formulated as particular facility location problems with a special location structure, which allows for polynomial-time algorithms in the biobjective case based on the principles of dynamic programming and threshold approaches. In addition, we show that several multiobjective variants of these representation problems are also solvable in polynomial time. Computational results obtained by these approaches on a wide range of randomly generated point sets are presented and discussed. (C) 2015 Elsevier Ltd. All rights reserved.

关键词： Multiobjective discrete optimization Representation Dynamic programming threshold algorithm

来源：评论

学校读者我要写书评

暂无评论

Efficient processing of optimal meeting point queries in Euclidean space and road networks

引用

KNOWLEDGE AND INFORMATION SYSTEMS 2015年第2期42卷 319-351页

作者： Yan, Da Zhao, Zhou Ng, Wilfred Hong Kong Univ Sci & Technol Dept Comp Sci & Engn Kowloon Hong Kong Peoples R China

Finding an optimal meeting point (OMP) for a group of people (or a set of objects) at different locations is an important problem in spatial query processing. There are many real-life applications related to this problem, such as determining the location of a conference venue, deciding the pick-up location of a tourist bus, and planing tactics of artificial intelligence in real-time strategy games. Formally, given a set of query points in a spatial setting , an OMP query fetches the point that minimizes a cost function defined over the distances from to all points in . Since there are infinitely many locations in a given space setting, it is infeasible to examine all of them to find the OMP, and thus, the problem is challenging. In this paper, we study OMP queries in the following two spatial settings which are common in real-life applications: Euclidean space and road networks. In the setting of Euclidean space, we propose a general framework for answering all OMP query variants and also identify the best algorithms for particular types of OMP queries in the literature. In the setting of road networks, we study how to access only part of the road network and examine part of the candidates. Specifically, we explore two pruning techniques, namely Euclidean distance bound and threshold algorithm, which help improve the efficiency of OMP query processing. Extensive experiments are conducted to demonstrate the efficiency of our proposed approaches on both real and synthetic datasets.

关键词： Optimal meeting point Spatial query processing Road network threshold algorithm

来源：评论

学校读者我要写书评

暂无评论

A Multisensor Data-Fusion Approach for ADL and Fall classification

引用

IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT 2016年第9期65卷 1960-1967页

作者： Ando, Bruno Baglio, Salvatore Lombardo, Cristian Orazio Marletta, Vincenzo Univ Catania Dept Elect Elect & Informat Engn I-95126 Catania Italy

This paper deals with an advanced approach for the monitoring of elders and people with neurological pathologies (e.g., Alzheimer). The system that adopts a multisensor approach is able to recognize critical events, such as falls or prolonged inactivity, to monitor the user posture, and to notify the alerts to caregivers. In particular, this paper focuses on smart algorithms developed for the activities of daily living (ADL) classification, which use the information provided by inertial sensors embedded in the user device. In particular, a novel multisensor data-fusion approach, combining data from an accelerometer and a gyroscope, is presented. Apart from alert management, the information provided by this system is useful to track the evolution of the user pathology, also during rehabilitation tasks. Results obtained during tests with users demonstrate suitable performances of the adopted paradigm, in terms of sensitivity and specificity, in performing falls and ADL classification tasks. The average value of the sensitivity index for the classes of falls and ADL considered through this paper is 0.81, while the average value of the specificity index is 0.98.

关键词： Ambient Assisted Living (AAL) activities of daily living (ADL) fall detection inertial sensors smartphone threshold algorithm user posture user safety monitoring

来源：评论

学校读者我要写书评

暂无评论

Detecting Slipping-Like Perturbations by Using Adaptive Oscillators

引用

ANNALS OF BIOMEDICAL ENGINEERING 2015年第2期43卷 416-426页

作者： Tropea, Peppino Vitiello, Nicola Martelli, Dario Aprigliano, Federica Micera, Silvestro Monaco, Vito Scuola Super Sant Anna BioRobot Inst I-56025 Pisa Italy Don Carlo Gnocchi Fdn I-50143 Florence Italy Ecole Polytech Fed Lausanne Translat Neural Engn Lab Ctr Neuroprosthet CH-1015 Lausanne Switzerland Ecole Polytech Fed Lausanne Sch Engn Inst Bioengn CH-1015 Lausanne Switzerland

This study introduces a novel algorithm to detect unexpected slipping-like perturbations based on the comparison between actual leg joint angles and those predicted by a pool of adaptive oscillators. The approach grounds on the hypothesis that during postural transitions, the difference between these datasets diverges and can early signal that the dynamic balance is challenged. To test this hypothesis, leg joint angles of twelve healthy young participants were recorded while undergoing four different perturbations delivered during steady locomotion. Joint angles were estimated after spanning the whole domain of the adaptive oscillator dynamics. Results confirmed that the implemented strategy allows to early detect a postural transition induced by a slipping-like perturbation: the best performance is represented by a mean detection time ranging between 150 and 250 ms and a low rate (lower than 10%) of false alarms. On the whole, the proposed approach is efficient even if it is based on a quite simple threshold-based algorithm. Moreover, it does not need any falling-based training before being implemented, is not computationally heavy, and is not subject dependent. Finally, since it is based on leg joint angles, it appears well suited to be implemented in lower-limb orthoses/prostheses already equipped with joint position sensors.

关键词： Pre-fall detection Adaptive oscillators Perturbation Walking Joint angles threshold algorithm

来源：评论

学校读者我要写书评

暂无评论

Row-level algorithm to improve real-time performance of glass tube defect detection in the production phase

引用

IET IMAGE PROCESSING 2020年第12期14卷 2911-2921页

作者： De Vitis, Gabriele A. Foglia, Pierfrancesco Prete, Cosimo A. Univ Pisa Dipartimento Ingn Informaz Via Diotisalvi 2 Pisa Italy

In the case of the glass tube for pharmaceutical applications, high-quality defect detection is made via inspection systems based on image processing. Such processing must be fast enough to guarantee real-time inspection and to meet the increasing rate and quality required by the market. Defect detection is complex due to specific problems of the production process: vibration, rotation and irregularity of the tube. All these aspects prevent the efficient use of known techniques. The authors present an algorithm that decreases the processing time of the defect detection phase. The algorithm is based on a moving average filter working at row level, that allows to minimize the effects of rotation, vibration, and irregularity of the tube. Luminosity variations due to the tube curvature are cut by the filter and a threshold algorithm can be applied. They made the evaluation considering different solutions taken from literature. The algorithm outperforms, in processing time, all these solutions with increased accuracy. Experimental measures show that the algorithm achieves a throughput gain of 2.6 times with respect to Canny. They develop also a methodology to get the best values for the algorithm parameters directly at the factory, during the change of production batches.

关键词： quality control production engineering computing automatic optical inspection pipes edge detection pharmaceuticals vibrations production batches row-level algorithm real-time performance glass tube defect detection production phase pharmaceutical applications high-quality defect detection inspection systems image processing real-time inspection production rate pharmaceutical market production process imperfect cylindrical shape detection techniques processing time defect detection phase glass tube inspection row level perfect tube circular shape threshold algorithm defect size detection

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：