A Parallel Programming Pattern Based on Directed Acyclic Graph

2013 ◽  
Vol 303-306 ◽  
pp. 2165-2169
Author(s):  
Zheng Meng ◽  
Ying Lin ◽  
Yan Kang ◽  
Qian Yu
Keyword(s):  
Parallel Programming ◽  
Computer Technology ◽  
Directed Acyclic Graph ◽  
Large Scale ◽  
Algorithm Design ◽  
Batch Processing ◽  
Acyclic Graph ◽  
Static Data ◽  
Definition Of

With the development of computer technology, multi-core programming is now becoming hot issues. Based on directed acyclic graph, this paper gives definition of a number of executable operations and establishes a parallel programming pattern. Using verticies to represent tasks and edges to represent communication between vertex, this parallel programming pattern let the programmers easily to identify the available concurrency and expose it for use in the algorithm design. The proposed pattern can be used for large-scale static data batch processing in multi-core environments and can bring lots of convenience when deal with complex issues.

scholarly journals A path recorder algorithm for Multiple Longest Common Subsequences (MLCS) problems

2020 ◽  
Vol 36 (10) ◽  
pp. 3035-3042
Author(s):  
Shiwei Wei ◽  
Yuping Wang ◽  
Yuanchao Yang ◽  
Sen Liu
Keyword(s):  
Dna Sequences ◽  
Directed Acyclic Graph ◽  
Large Scale ◽  
Search Time ◽  
Longest Common Subsequence ◽  
Supplementary Information ◽  
Acyclic Graph ◽  
Longest Common Subsequences ◽  
Longest Path ◽  
Longest Paths

Abstract Motivation Searching the Longest Common Subsequences of many sequences is called a Multiple Longest Common Subsequence (MLCS) problem which is a very fundamental and challenging problem in many fields of data mining. The existing algorithms cannot be applicable to problems with long and large-scale sequences due to their huge time and space consumption. To efficiently handle large-scale MLCS problems, a Path Recorder Directed Acyclic Graph (PRDAG) model and a novel Path Recorder Algorithm (PRA) are proposed. Results In PRDAG, we transform the MLCS problem into searching the longest path from the Directed Acyclic Graph (DAG), where each longest path in DAG corresponds to an MLCS. To tackle the problem efficiently, we eliminate all redundant and repeated nodes during the construction of DAG, and for each node, we only maintain the longest paths from the source node to it but ignore all non-longest paths. As a result, the size of the DAG becomes very small, and the memory space and search time will be greatly saved. Empirical experiments have been performed on a standard benchmark set of both DNA sequences and protein sequences. The experimental results demonstrate that our model and algorithm outperform the related leading algorithms, especially for large-scale MLCS problems. Availability and implementation This program code is written by the first author and can be available at https://www.ncbi.nlm.nih.gov/nuccore and https://blog.csdn.net/wswguilin. Supplementary information Supplementary data are available at Bioinformatics online.

scholarly journals A fast and memory efficient MLCS algorithm by character merging for DNA sequences alignment

2019 ◽  
Author(s):  
Sen Liu ◽  
Yuping Wang ◽  
Wuning Tong ◽  
Shiwei Wei
Keyword(s):  
Dna Sequences ◽  
Directed Acyclic Graph ◽  
Large Scale ◽  
State Of The Art ◽  
Longest Common Subsequence ◽  
Sequence Length ◽  
Acyclic Graph ◽  
Character Sequences ◽  
Common Subsequence ◽  
Memory Efficient

Abstract Motivation Multiple longest common subsequence (MLCS) problem is searching all longest common subsequences of multiple character sequences. It appears in many fields such as data mining, DNA alignment, bioinformatics, text editing and so on. With the increasing in sequence length and number of sequences, the existing dynamic programming algorithms and the dominant point-based algorithms become ineffective and inefficient, especially for large-scale MLCS problems. Results In this paper, by considering the characteristics of DNA sequences with many consecutively repeated characters, we first design a character merging scheme which merges the consecutively repeated characters in the sequences. As a result, it shortens the length of sequences considered and saves the space of storing all sequences. To further reduce the space and time costs, we construct a weighted directed acyclic graph which is much smaller than widely used directed acyclic graph for MLCS problems. Based on these techniques, we propose a fast and memory efficient algorithm for MLCS problems. Finally, the experiments are conducted and the proposed algorithm is compared with several state-of-the art algorithms. The experimental results show that the proposed algorithm performs better than the compared state-of-the art algorithms in both time and space costs. Availability and implementation https://www.ncbi.nlm.nih.gov/nuccore and https://github.com/liusen1006/MLCS.

CONCEPT OF THE IMPROVEMENT OF A KEY PUBLIC SPACE (USING THE EXAMPLE OF «ALLEY OF ARCHITECTS», VORONEZH)

2020 ◽  
pp. 97-109
Author(s):  
С. Л. Подвальный ◽  
О. А. Сотникова ◽  
Я. А. Золотухина
Keyword(s):  
Urban Environment ◽  
Public Space ◽  
Large Scale ◽  
Economic Value ◽  
Ecological Condition ◽  
Territory Design ◽  
Definition Of ◽  
The City ◽  
Modern Technologies ◽  
Intensive Growth

Постановка задачи. В настоящее время формирование современной комфортной городской среды приобретает особое социально-экономическое значение и выдвигается в число приоритетных государственных масштабных программ. В связи с этим необходимо разработать концепцию благоустройства ключевого общественного пространства, а именно: определить основные и сопутствующие функции данной территории, создать эскизное предложение проекта благоустройства с учетом всех необходимых норм и стандартов, внедрить современные технологии. Результаты. Выполнен эскизный дизайн-проект «Аллеи архитекторов» по ул. Орджоникидзе г. Воронеж, включающий в себя основные элементы по зонированию территории, проектированию акцентных объектов и внедрению инновационных технологий «умного города», позволяющих повысить уровень комфорта горожан. Выводы. Благоустройство населенных мест приобретает особое значение в условиях дискомфорта среды. С выполнением комплекса мероприятий, направленных на благоустройство, и с внедрением современных технологий значительно улучшается экологическое состояние, внешний облик города. Оздоровление и модернизация среды, которая окружает человека в городе, благотворно влияет на психофизическое состояние, что особенно важно в период интенсивного роста городов. Statement of the problem. Currently the formation of the modern comfortable urban environment is gaining a special social and economic value and moving forward in the priorities of state large-scale programs. The purpose of development of the concept of improvement of public space is definition of the main and accompanying functions of this territory, design of the outline offer of the project of improvement considering all necessary norms and standards and implementation of modern technologies. Results. The conceptual project of “Alley of Architects” includes the basic elements of territory zoning, design of accent objects and implementation of technologies of a “smart-city”. These elements allow one to increase the level of comfort of inhabitants. Conclusions. Improvement of the inhabited places is of particular importance in the conditions of discomfort of the environment. Carrying out a complex of the actions directed to gardening and improvement, introducing modern technologies, the ecological condition, the physical appearance of the city considerably improves. Improvement and modernization of the environment which surrounds the person in the city influences a psychophysical state well that especially important during intensive growth of the cities.

Bottlenecks in the Implementation of On-Site Wastewater Treatment Plants on a Large Scale in The Netherlands

1990 ◽  
Vol 22 (3-4) ◽  
pp. 291-298
Author(s):  
Frits A. Fastenau ◽  
Jaap H. J. M. van der Graaf ◽  
Gerard Martijnse
Keyword(s):  
Wastewater Treatment ◽  
The Netherlands ◽  
Large Scale ◽  
Wastewater Treatment Plants ◽  
Housing Stock ◽  
Research Work ◽  
Field Research ◽  
Domestic Wastewater ◽  
Research Programme ◽  
Definition Of

More than 95 % of the total housing stock in the Netherlands is connected to central sewerage systems and in most cases the wastewater is treated biologically. As connection to central sewerage systems has reached its economic limits, interest in on-site treatment of the domestic wastewater of the remaining premises is increasing. A large scale research programme into on-site wastewater treatment up to population equivalents of 200 persons has therefore been initiated by the Dutch Ministry of Housing, Physical Planning and Environment. Intensive field-research work did establish that the technological features of most on-site biological treatment systems were satisfactory. A large scale implementation of these systems is however obstructed in different extents by problems of an organisational, financial and/or juridical nature and management difficulties. At present research is carried out to identify these bottlenecks and to analyse possible solutions. Some preliminary results are given which involve the following ‘bottlenecks':-legislation: absence of co-ordination and absence of a definition of ‘surface water';-absence of subsidies;-ownership: divisions in task-setting of Municipalities and Waterboards; divisions involved with cost-sharing;-inspection; operational control and maintenance; organisation of management;-discharge permits;-pollution levy;-sludge disposal. Final decisions and practical elaboration of policies towards on-site treatment will have to be formulated in a broad discussion with all the authorities and interest groups involved.

Random graphs

2018 ◽  
Author(s):  
Mark Newman
Keyword(s):  
Random Graph ◽  
Random Graphs ◽  
Large Scale ◽  
Random Network ◽  
Graph Model ◽  
Clustering Coefficient ◽  
Giant Component ◽  
Random Graph Model ◽  
Definition Of ◽  
Average Size

An introduction to the mathematics of the Poisson random graph, the simplest model of a random network. The chapter starts with a definition of the model, followed by derivations of basic properties like the mean degree, degree distribution, and clustering coefficient. This is followed with a detailed derivation of the large-scale structural properties of random graphs, including the position of the phase transition at which a giant component appears, the size of the giant component, the average size of the small components, and the expected diameter of the network. The chapter ends with a discussion of some of the shortcomings of the random graph model.

Research on Hyperpaths in the Urban Rail Transit Network

2014 ◽  
Vol 488-489 ◽  
pp. 1439-1443
Author(s):  
Jin Hai Li ◽  
Jian Feng Liu
Keyword(s):  
Large Scale ◽  
Urban Rail Transit ◽  
Rail Transit ◽  
Transit Network ◽  
Travel Costs ◽  
Urban Rail ◽  
Distinctive Structure ◽  
Feasible Path ◽  
Definition Of ◽  
Urban Rail Transit Network

Hyperpaths enumeration is one of the basic procedures in many traffic planning issues. As a result of its distinctive structure, hyperpaths in Urban Rail Transit Network (URTN) are different from those in road network. Typically, one may never visit a station more than once and would never transfer from one line to another that has been visited in a loopless URTN, meaning that stations a hyperpath traversed cannot be repeated, neither do lines in loopless networks. This paper studies the relationships between feasible path and the shortest path in terms of travel costs. In this paper, a new definition of hyperpath in URTN is proposed and a new algorithm based on the breadth first searching (BFS) method is presented to enumerate the hyperpaths. The algorithm can safely avoid hyperpath omission and can even be applied in networks containing loops as well. The influence of parameters on hyperpaths is studied by experimentally finding hyperpaths in the subway network in Beijing. A group of suggested parameter pairs are then given. Finally, a numerical experiment is used to illustrate the validity of the proposed algorithm. The results imply the significance of the convergence of the BFS algorithm which can be used to search hyperpaths in large scale URTN even with loop.

scholarly journals Characteristics of Models of Farms in the European Union

2021 ◽  
Vol 13 (9) ◽  
pp. 4772
Author(s):  
Hanna Klikocka ◽  
Aneta Zakrzewska ◽  
Piotr Chojnacki
Keyword(s):  
European Union ◽  
Minimum Wage ◽  
Large Scale ◽  
The European Union ◽  
Family Farms ◽  
Agricultural Income ◽  
Commercial Farms ◽  
Standard Output ◽  
Definition Of ◽  
The Eu

The article describes and sets the definition of different farm models under the categories of being family, small, and large-scale commercial farms. The distinction was based on the structure of the workforce and the relationship between agricultural income and the minimum wage. Family farms were dominated by the farming family providing the labour and their income per capita exceeded the net minimum wage in the country. The larger commercial farms feature a predominance of hired labour. Based on surveys, it was found that in 2016 in the EU-28 there were 10,467,000 farms (EU-13—57.3%, EU-15—42.7%). They carried out agricultural activities on an area of 173,338,000 ha (EU-13—28.5%, EU-15—71.5%). Countries of the EU-28 generated a standard output (SO) amounting to EUR 364,118,827,100 (EU-13—17.2% and EU-15—82.8%). After the delimitation, it was shown that small farming (70.8%) was the predominant form of management in the European Union (EU-13—88.2% and EU-15—79.8%) compared to family farming (18.4%) (EU-13—10.5% and EU-15—29%). In most EU countries the largest share of land resources pertains to small farms (35.6%) and family farms (38.6%) (UAA—utilised agricultural area of farms).

scholarly journals IoT-enabled directed acyclic graph in spark cluster

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Jahwan Koo ◽  
Nawab Muhammad Faseeh Qureshi ◽  
Isma Farah Siddiqui ◽  
Asad Abbas ◽  
Ali Kashif Bashir
Keyword(s):  
Distributed Computing ◽  
Real Time ◽  
Directed Acyclic Graph ◽  
Random Access ◽  
Heterogeneous Data ◽  
The Body ◽  
Computing Environment ◽  
Time Data ◽  
Acyclic Graph ◽  
Sensory Data

Abstract Real-time data streaming fetches live sensory segments of the dataset in the heterogeneous distributed computing environment. This process assembles data chunks at a rapid encapsulation rate through a streaming technique that bundles sensor segments into multiple micro-batches and extracts into a repository, respectively. Recently, the acquisition process is enhanced with an additional feature of exchanging IoT devices’ dataset comprised of two components: (i) sensory data and (ii) metadata. The body of sensory data includes record information, and the metadata part consists of logs, heterogeneous events, and routing path tables to transmit micro-batch streams into the repository. Real-time acquisition procedure uses the Directed Acyclic Graph (DAG) to extract live query outcomes from in-place micro-batches through MapReduce stages and returns a result set. However, few bottlenecks affect the performance during the execution process, such as (i) homogeneous micro-batches formation only, (ii) complexity of dataset diversification, (iii) heterogeneous data tuples processing, and (iv) linear DAG workflow only. As a result, it produces huge processing latency and the additional cost of extracting event-enabled IoT datasets. Thus, the Spark cluster that processes Resilient Distributed Dataset (RDD) in a fast-pace using Random access memory (RAM) defies expected robustness in processing IoT streams in the distributed computing environment. This paper presents an IoT-enabled Directed Acyclic Graph (I-DAG) technique that labels micro-batches at the stage of building a stream event and arranges stream elements with event labels. In the next step, heterogeneous stream events are processed through the I-DAG workflow, which has non-linear DAG operation for extracting queries’ results in a Spark cluster. The performance evaluation shows that I-DAG resolves homogeneous IoT-enabled stream event issues and provides an effective stream event heterogeneous solution for IoT-enabled datasets in spark clusters.

Risk identification and modeling for blockchain-enabled container shipping

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Son Nguyen ◽  
Peggy Shu-Ling Chen ◽  
Yuquan Du
Keyword(s):  
Design Methodology ◽  
Directed Acyclic Graph ◽  
Risk Identification ◽  
Container Shipping ◽  
Content Type ◽  
Acyclic Graph ◽  
Operational Risks ◽  
Systems Security ◽  
Event Risk ◽  
Potential Risks

PurposeAlthough being considered for adoption by stakeholders in container shipping, application of blockchain is hindered by different factors. This paper investigates the potential operational risks of blockchain-integrated container shipping systems as one of such barriers.Design/methodology/approachLiterature review is employed as the method of risk identification. Scientific articles, special institutional reports and publications of blockchain solution providers were included in an inclusive qualitative analysis. A directed acyclic graph (DAG) was constructed and analyzed based on network topological metrics.FindingsTwenty-eight potential risks and 47 connections were identified in three groups of initiative, transitional and sequel. The DAG analysis results reflect a relatively well-connected network of identified hazardous events (HEs), suggesting the pervasiveness of information risks and various multiple-event risk scenarios. The criticality of the connected systems' security and information accuracy are also indicated.Originality/valueThis paper indicates the changes of container shipping operational risk in the process of blockchain integration by using updated data. It creates awareness of the emerging risks, provides their insights and establishes the basis for further research.

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