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Modified vector rotational CORDIC (MVR-CORDIC) algorithm and architecture

IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS II-ANALOG AND DIGITAL SIGNAL PROCESSING 2001年第6期48卷 548-561页

作者： Wu, CS Wu, AY Natl Cent Univ Dept Elect Engn Chungli 320 Taiwan Natl Taiwan Univ Dept Elect Engn Taipei 106 Taiwan

The CORDIC algorithm is a well-known iterative method for the computation of vector rotation. However, the major disadvantage is its relatively slow computational speed. For applications that require forward rotation (or vector rotation) only, we propose a new scheme, the modified vector rotational CORDIC (MVR-CORDIC) algorithm, to improve the speed performance of CORDIC algorithm. The basic idea of the proposed scheme is to reduce the iteration number directly while maintaining the SQNR performance. This can be achieved by modifying the basic microrotation procedure of CORDIC algorithm. Meanwhile, three searching algorithms are suggested to find the corresponding directional and rotational sequences so as to obtain the best SQNR performance. Three SQNR performance refinement schemes are also suggested in this paper. Namely, the selective prerotation scheme, selective scaling scheme, and iteration-tradeoff scheme. They can reduce and balance the quantization errors encountered in both microrotation and scaling phases so as to further improve the overall SQNR performance. Then, by combining these three refinement schemes, we provide a systematic design flow as well as the optimization procedure in the application of MVR-CORDIC algorithm. Finally, we present two VLSI architectures for the MVR-CORDIC algorithm. It shows that by using the proposed MVR-CORDIC algorithm, we can save 50% execution time in the iterative CORDIC structure, or 50% hardware complexity in the parallel CORDIC structure compared with the conventional CORDIC scheme.

关键词： CORDIC algorithm DSP MVR-CORDIC algorithm searching algorithms VLSI

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An algorithm for estimating Box-Cox transformation parameter in ANOVA

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COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2017年第8期46卷 6424-6435页

作者： Dag, Osman Ilk, Ozlem Hacettepe Univ Dept Biostat Ankara Turkey Middle East Tech Univ Dept Stat TR-06800 Ankara Turkey

In this study, we construct a feasible region, in which we maximize the likelihood function, by using Shapiro-Wilk and Bartlett's test statistics to obtain Box-Cox power transformation parameter for solving the issues of non-normality and/or heterogeneity of variances in analysis of variance (ANOVA). Simulation studies illustrate that the proposed approach is more successful in attaining normality and variance stabilization, and is at least as good as the usual maximum likelihood estimation (MLE) in estimating the transformation parameter for different conditions. Our proposed method is illustrated on two real-life datasets. Moreover, the proposed algorithm is released under R package AID under the name of "boxcoxfr" for implementation.

关键词： Data transformation Homogeneity test Normality test searching algorithms Statistical software

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AdaGT: An Adaptive Group Testing Method for Improving Efficiency and Sensitivity of Large-Scale Screening Against COVID-19

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IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 2022年第2期19卷 646-662页

作者： Xia, Xiaofang Liu, Yang Xiao, Yang Cui, Jiangtao Yang, Bo Peng, Yanguo Xidian Univ Sch Comp Sci & Technol Xian 710071 Peoples R China Univ Alabama Dept Comp Sci Tuscaloosa AL 35487 USA Univ Toronto Dept Elect & Comp Engn Toronto ON M5S 3G4 Canada

The ongoing coronavirus disease 2019 (COVID-19) is a pandemic causing millions of deaths, devastating social and economic disruptions. Testing individuals for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the pathogen of COVID-19, is critical for mitigating and containing COVID-19. Many countries are implementing group testing strategies against COVID-19 to improve testing capacity and efficiency while saving required workloads and consumables. A group of individuals' nasopharyngeal/oropharyngeal (NP/OP) swab samples is mixed to conduct one test. However, existing group testing methods neglect the fact that mixing samples usually leads to substantial dilution of viral ribonucleic acid (RNA) of SARS-CoV-2, which seriously impacts the sensitivity of tests. In this paper, we aim to screen individuals infected with COVID-19 with as few tests as possible, under the premise that the sensitivity of tests is high enough. To achieve this goal, we propose an Adaptive Group Testing (AdaGT) method. By collecting information on the number of positive and negative samples that have been identified during the screening process, the AdaGT method can estimate the ratio of positive samples in real-time. Based on this ratio, the AdaGT algorithm adjusts its testing strategy adaptively between an individual testing strategy and a group testing strategy. The group size of the group testing strategy is carefully selected to guarantee that the sensitivity of each test is higher than a predetermined threshold and that this group contains at most one positive sample on average. Theoretical performance analysis on the AdaGT algorithm is provided and then validated in experiments. Experimental results also show that the AdaGT algorithm outperforms existing methods in terms of efficiency and sensitivity.

关键词： Testing COVID-19 Sensitivity Coronaviruses Pandemics Economics RNA searching algorithms tree binary tree searching COVID-19 SARS-CoV-2 group testing screening sensitivity efficiency

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Comparison of statistical methods for subnetwork detection in the integration of gene expression and protein interaction network

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BMC BIOINFORMATICS 2017年第1期18卷 1-6页

作者： He, Hao Lin, Dongdong Zhang, Jigang Wang, Yu-ping Deng, Hong-wen Tulane Univ Sch Publ Hlth & Trop Med Ctr Bioinformat & Genom Dept Biostat & Bioinformat 1440 Canal StSuite 2001 New Orleans LA 70112 USA Tulane Univ Dept Biomed Engn New Orleans LA 70118 USA

Background: With the advancement of high-throughput technologies and enrichment of popular public databases, more and more research focuses of bioinformatics research have been on computational integration of network and gene expression profiles for extracting context-dependent active subnetworks. Many methods for subnetwork searching have been developed. Scoring and searching algorithms present a range of computational considerations and implementations. The primary goal of present study is to comprehensively evaluate the performance of different subnetwork detection methods. Eleven popular methods were selected for comprehensive comparison. Results: First, taking into account the dependence of genes given a protein-protein interaction (PPI) network, we simulated microarray gene expression data under case and control conditions. Then each method was applied to the simulated data for subnetwork identification. Second, a large microarray data set of prostate cancer was used to assess the practical performance of each method. Using both simulation studies and a real data application, we evaluated the performance of different methods in terms of recall and precision. Conclusions: jActiveModules, PinnacleZ and WMAXC performed well in identifying subnetwork with relative high precision and recall. BioNet performed very well only in precision. As none of methods outperformed other methods overall, users should choose an appropriate method based on the purposes of their studies.

关键词： Active subnetworks Protein-protein interaction searching algorithms

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Estimating Box-Cox power transformation parameter via goodness-of-fit tests

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COMMUNICATIONS IN STATISTICS-SIMULATION AND COMPUTATION 2017年第1期46卷 91-105页

作者： Asar, Ozgur Ilk, Ozlem Dag, Osman Univ Lancaster Lancaster Med Sch CHICAS Lancaster England Middle East Tech Univ Dept Stat Ankara Turkey Hacettepe Univ Dept Biostat Fac Med Ankara Turkey

Box-Cox power transformation is a commonly used methodology to transform the distribution of the data into a normal distribution. The methodology relies on a single transformation parameter. In this study, we focus on the estimation of this parameter. For this purpose, we employ seven popular goodness-of-fit tests for normality, namely Shapiro-Wilk, Anderson-Darling, Cramer-von Mises, Pearson Chi-square, Shapiro-Francia, Lilliefors and Jarque-Bera tests, together with a searching algorithm. The searching algorithm is based on finding the argument of the minimum or maximum depending on the test, i.e., maximum for the Shapiro-Wilk and Shapiro-Francia, minimum for the rest. The artificial covariate method of Dag etal. (2014) is also included for comparison purposes. Simulation studies are implemented to compare the performances of the methods. Results show that Shapiro-Wilk and the artificial covariate method are more effective than the others and Pearson Chi-square is the worst performing method. The methods are also applied to two real-life datasets. The R package AID is proposed for implementation of the aforementioned methods.

关键词： Artificial covariate Data transformation Normality tests searching algorithms Statistical software

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Walking algorithms for point location in TIN models

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COMPUTATIONAL GEOSCIENCES 2012年第4期16卷 853-869页

作者： Soukal, Roman Malkova, Martina Kolingerova, Ivana Univ W Bohemia Fac Sci Appl Dept Comp Sci & Engn Plzen 30614 Czech Republic

Finding which triangle in a planar or 2.5D triangle mesh contains a query point (so-called point location problem) is a frequent task in geosciences, especially when working with triangulated irregular network models. Usually, a large number of point locations has to be performed, and so there is a need for fast algorithms having minimal additional memory requirements and resistant to changes in the triangulation. So-called walking algorithms offer low complexity, easy implementation, and negligible additional memory requirements, which makes them suitable for such applications. In this article, we focus on these algorithms, summarize, and compare them with regard to their use in geosciences. Since such a summary has not been done yet, our article should serve those who are dealing with this problem in their application to decide which algorithm would be the best for their solution. Moreover, the influence of the triangulation type on the number of the visited triangles is discussed.

关键词： Point searching searching algorithms Planar triangulation TIN models Terrain models

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Pyramid Search: Skip Ring Data Structure-Based New searching Algorithm

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JOURNAL OF CIRCUITS SYSTEMS AND COMPUTERS 2018年第14期27卷 1850218.1-1850218.23页

作者： Aksu, Mustafa Karci, Ali Sutcu Imam Univ Vocat Sch Tech Sci Dept Comp Technol Kahramanmaras Turkey Inonu Univ Fac Engn Dept Comp Engn Malatya Turkey

Our new algorithm and data structure, pyramid search (PS) and skip ring, were created with the help of circular linked list and skip list algorithms and data structures. In circular linked list, operations were performed on a single circular list. Our new data structure consists of circular linked lists formed in layers which were linked in a pyramid way. Time complexity of searching, insertion and deletion algorithms equal to O (1gN) in an N-element skip ring data structure. Therefore, skip ring data structure is employed more effectively (O(1gN)) in circumstances where circular linked lists (O(N)) are used. The priority is determined based on the searching frequency in PS which was developed in this study. Thus, the time complexity of searching is almost Theta(1) for N records data set. In this paper, the applications of searching algorithms like linear search (LS), binary search (BS) and PS were realized and the obtained results were compared. The obtained results demonstrated that the PS algorithm is superior to the BS algorithm.

关键词： Pyramid search skip ring data structures searching algorithms design of algorithms

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A Low Cost DFS-based Approach for Detection Speedup 4

A Low Cost DFS-based Approach for Detection Speedup

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4th Asia-Pacific Conference on Intelligent Robot Systems (ACIRS)

作者： Shih, Guan-Rong Tsai, Pei-Hsuan Natl Cheng Kung Univ Inst Mfg Informat & Syst Tainan Taiwan

ISBN: (纸本)9781728122298

Region of interest (ROI) is commonly used in many application areas, including medical imaging, wafer defect detection, geographical information systems and computer vision and optical character recognition. Within a ROI may lie individual points of interest (POI). Many searching algorithms are proposed to find POI. Based on how they decide their trajectories, they can be categorized to sequential search and convergent iterative search. However, they are not efficient and fast enough. In this paper, we proposed a low cost DFS-based searching algorithm to speedup finding POI when the POI are not evenly-distributed. Representative algorithms of sequential search and convergent iterative search are implemented to compare with our approach. The results reveal that our algorithm can efficiently find the POI with less cost in diverse POI distribution models.

关键词： defect detection medical image process searching algorithms regions of interest points of interest path planning optimization

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Designing E-Learning Content Using AGLOs 23

Designing E-Learning Content Using AGLOs

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23rd International Conference on System Theory, Control and Computing (ICSTCC)

作者： Costea, Felicia-Mirabela Chirila, Ciprian-Bogdan Cretu, Vladimir-Ioan Univ Politehn Timisoara Dept Comp & Informat Technol Timisoara Romania

ISBN: (纸本)9781728106991

Learning technologies for autonomous study of computer programming abstract concepts are not yet available on a large scale. In this sense we propose an e-learning content design to meet both: the needs of the tutor in the class and the needs of the student able to study on his own at home. Theoretical materials based on static text have the advantage of presenting all the notions in details but the drawback of being impossible to exercise with. On the other hand, Auto-Generative Learning Objects are designed for exercising and testing the understanding of abstractions and concepts for computer programming. AGLOs were not created for presenting in detail the theoretical descriptions of concepts. In this sense we propose a design of a mixed learning content including: static text theory, dynamic JavaScript demos, dynamic AGLOs, static code images and proposed exercises to be manually assessed.

关键词： generative learning objects auto-generative learning objects data structures searching algorithms sorting algorithms

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Representation of Regional Gravity Fields by Radial Base Functions

Representation of Regional Gravity Fields by Radial Base Fun...

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General Assembly of the International-Association-of-Geodesy/24th General Assembly of the International-Union-of-Geodesy-and-Geophysics

作者： Antoni, M. Keller, W. Weigelt, M. Univ Stuttgart Geodat Inst D-70174 Stuttgart Germany

ISBN: (纸本)9783540854258

The research aims at an investigation of the optimal choice of local base functions, to derive a regional solution of the gravity field. Therefore, the representation of the gravity field is separated into a global and a residual signal, which includes the regional details. To detect these details, a superposition of localizing radial base functions is used. The base functions are developed from one mother function, and modified by four parameters. These arguments can be separated into two coordinates, one scale factor and a shape parameter. The observations of a few residual gravity fields are simulated by orbit integration and the energy-balance technique, in order to test the current approach. After selecting a region of interest, the parameters of the base functions are estimated. In order to get the optimal positions, two searching algorithms are compared. In the first algorithm the scale factors are estimated, while the positions and shape parameters are fixed. This method requires no initial values, because of the linear, but ill-posed and maybe ill-conditioned problem, but usually a regularization is necessary. The second algorithm searches possible positions for one base function in each step, until a termination condition is fulfilled, and improves the positions and scale factors in one adjustment. The results in the second case are better and faster for the test fields, but they depend on the initial values, the number of iterations and an assumption of an approximate constant orbit height.

关键词： Local base function Radial base function Regional gravity field Energy-balance technique searching algorithms

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