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A depth-first search algorithm for Optimizing the Gravity Pipe Networks Layout

WATER RESOURCES MANAGEMENT 2019年第13期33卷 4583-4598页

作者： Weyne Rodrigues, Gustavo Paiva Magalhaes Costa, Luis Henrique Farias, Guilherme Marques Holanda de Castro, Marco Aurelio Vale Acarau State Univ Dept Civil Engn Sobral Ceara Brazil Fed Inst Educ Sci & Technol Ceara Dept Civil Engn Fortaleza Ceara Brazil Univ Fed Ceara Dept Civil Engn Fortaleza Ceara Brazil

The layout is displayed in one of the most complex tasks in the gravity pipe network project because there are several factors to consider and often a choice of unassociated or smaller layout. Currently, the designer's experience is needed so different layout alternatives be analyzed to reduce the depths of the network. Generally, this operation is manual and does not ensure the best result. For this research, a depth-first search algorithm was presented, which allows the optimization of the layout of a gravity pipe network, assessing the topographic conditions of the manholes (nodes), leading to a layout that has the sum of lower unfavorable slopes. A hypothetical and a real network were used. The computational time required was considered negligible. The results showed a robust model, which works for the complete layout of any network, of any size, resulting in the lowest possible depths.

关键词： Gravity Pipe networks Optimal layout depth-first search algorithm search algorithms

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The unprecedented spatial extent and intensity of the 2021 summer extreme heatwave event over the Western North American regions

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WEATHER AND CLIMATE EXTREMES 2023年 41卷

作者： Lo, Shih-How Chen, Cheng-Ta Hsu, Huang-Hsiung Shih, Ming-Fu Liang, Hsin-Chien Acad Sinica Res Ctr Environm Change Taipei Taiwan Natl Taiwan Normal Univ Dept Earth Sci Taipei Taiwan Natl Taiwan Normal Univ Dept Geog Taipei Taiwan Natl Taiwan Normal Univ Dept Earth Sci 88Sect 4Ting Chou Rd Taipei 11677 Taiwan

A record-breaking heatwave event occurred in western North America in the summer of 2021. Previous studies on a similar event's uniqueness and return period are typically estimated based on extreme value analysis and statistics of selected stations or area-mean temperature data. The extreme statistics results are no longer valid if moved to another location. Further, the detailed evolution of spatial extent and intensity through its duration is not quantified and compared to other historical heatwave events to claim its rarity and severity. By applying an event detection and tracking algorithm to heatwaves, we first construct an archive for all the events over the region since 1979 based on daily maximum temperature data from reanalysis. It documented the daily mean temperature anomalies, affected areas, and durations of all individual heatwave events. It is, therefore, possible to objectively compare and rank the magnitudes of all historical heatwave events by examining the total integrated effects from the intensity, impact region, and duration. With the global mean warming background increase of about 0.4 degrees C from 1979 to 2000 to 2000-2021, we found that the mean integrated magnitude and size of the top 100 heatwave events increased significantly by 155 & PLUSMN;88%. The dominant relative contributions to this integrated severity measure increase are +78 & PLUSMN;39% from the mean affected area, followed by +54 & PLUSMN;21% from duration and +7 & PLUSMN;4% from the intensity. With the above analyzed general historical increasing trend of heatwave event metrics, the severity of the 2021 summer heatwave over the region was due to a combination of its record-breaking event-mean spatial coverages (2090383 km2), highest normalized daily maximum temperature anomalies and long duration (11 days, in the top 4% of all heatwave events). This integrated severity measure of the event was more than double of any other historical heatwave event and about 17 times larger

关键词： Extreme event Heatwave Feature tracking depth-first search algorithm

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Tracking heatwave extremes from an event perspective

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WEATHER AND CLIMATE EXTREMES 2021年 34卷

作者： Lo, Shih-How Chen, Cheng-Ta Russo, Simone Huang, Wan-Ru Shih, Ming-Fu Natl Taiwan Normal Univ Dept Earth Sci 88Sect 4Ting Chou Rd Taipei 11677 Taiwan Acad Sinica Res Ctr Environm Changes Taipei 11529 Taiwan Inst Environm Protect & Res ISPRA Rome Italy Natl Taiwan Normal Univ Dept Geog Taipei 10029 Taiwan

Public perceptions of the risk posed by natural hazards and climate change are typically associated with extreme events. While there are studies focused on the detailed synergy for processes that lead to the event occurrence. Past literature working on long-term variations of global weather and climate extremes often studies the derived indices and applies further statistical models to data sampled from a fixed grid point or area. Our study, using extreme heatwave events as an example, proposes an alternative framework to track and analyze extremes from an event perspective to facilitate better climate risk communication. With a selected threshold of daily heatwave intensity and an objective spatial and temporal connectivity algorithm, we introduce an event-tracking method to automatically track all global heatwaves based on long-term reanalysis data. Two nearby but separate European heatwave events (Scandinavia and France) in 2003 are used to demonstrate the validity of our event-tracking method. We further highlight the genesis frequency, occurrence density, and tracks of all historical heatwave events over global land areas from 1979 to 2018. The contributions from heatwave intensity, the affected area, and temporal evolution to each extreme event are documented. With the retaining spatial and temporal evolutions of tracked heatwave events during their lifespans, the precursory and concurrent environmental conditions associated with the event can be further studied. The integrated size and scale measures of extreme heatwave events can be compared historically in a region and/or across different climate regimes. They also provide better information for the risk assessment on event-associated loss and damages, and can easily be extended to study compound hazards with intersections of different types of extreme events.

关键词： Extreme event Heatwave Feature tracking depth-first search algorithm

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Graph Theory Based Heuristic Approach for Minimum Break Point Set Determination in Large Scale Power Systems

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IEEE TRANSACTIONS ON POWER DELIVERY 2019年第3期34卷 963-970页

作者： Dolatabadi, Mohammad Damchi, Yaser Vali E Asr Univ Rafsanjan Dept Math Rafsanjan *** Iran Shahrood Univ Technol Fac Elect Engn & Robot Shahrood *** Iran

Coordination of directional relays in large-scale power systems that are multi-loop structured is a complicated and time consuming problem. Therefore, determination of the directional loops and the minimum break point set (MBPS) or a set close to it, which is essential to start relay coordination, is challenging. So far, several heuristics and exact methods have been proposed for the determination of the MBPS. In this paper, a new heuristic method based on a new implementation of depth-first search algorithm is proposed, which considerably facilitates the detection of directional loops (if any) in the network. The proposed method is tested on a 5-bus, four IEEE and four Polish test systems. The results show the efficiency of the proposed method in finding optimal or near-optimal solutions in a rational amount of time.

关键词： depth-first search algorithm directional loops minimum break point set relay coordination

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Design of a Labeling Scheme for 32-QAM Delayed Bit-Interleaved Coded Modulation

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SENSORS 2020年第12期20卷 3528.-3528.页

作者： Zhang, Zhe Zhou, Liang Du, Junyi Zhao, Yue Univ Elect Sci & Technol China Natl Key Lab Commun Chengdu 611731 Peoples R China Southwest China Inst Elect Technol Chengdu 610000 Peoples R China

It is very challenging to design the capacity-approaching labeling schemes for large constellations, such as 32-QAM, in delayed bit-interleaved coded modulation (DBICM). In this paper, we investigate the labeling design for 32-QAM DBICM with various numbers of bits delayed by one time slot. In particular, we aim to obtain the labeling schemes with a high DBICM channel capacity by searching the possible labeling schemes. To reduce the search space of the candidate labeling schemes, we propose the criteria that are necessary for good labeling. Based on the proposed criteria, a three-step search algorithm is proposed to obtain the candidate labeling efficiently. Numerical results demonstrate that the DBICM with our proposed labeling scheme can approach the capacity of 32-QAM within 0.015 dB at an information rate greater than 2.5 bits/symbol.

关键词： bit-interleaved coded modulation delayed bit-interleaved coded modulation gray labeling depth-first search algorithm

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An algorithm to construct conformable tubular networks that occupy arbitrary regions in R³

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APPLIED MATHEMATICAL MODELLING 2018年 62卷 194-206页

作者： Jiang, W. Ghasempour, F. Mendivil, F. Peterson, S. D. Vrscay, E. R. Univ Waterloo Dept Appl Math Waterloo ON N2L 3G1 Canada Acadia Univ Dept Math & Stat Wolfville NS B4P 2R6 Canada Univ Waterloo Dept Mech & Mechatron Engn Waterloo ON N2L 3G1 Canada

We describe a general algorithm for the construction of networks of tubes which occupy a specified, and possibly quite complicated, region D subset of R-3 as fully as possible. Such networks can be important in a variety of industrial applications ranging from heat exchangers to storage vessels. The algorithm is comprised of three fundamental steps: (i) decomposition of region D into subregions D-i, (ii) packing of each subregion with a set of parallel tubes using appropriate circle-packing algorithms and finally, (iii) connection of the tubes, both within each subregion D-i as well as between neighboring regions. Such a design problem is extremely ill-posed: For a given region D, our algorithm can produce an enormous number of networks, which generally requires that a much smaller number of "best" networks be isolated. Such isolation can be accomplished by ranking the networks based on some application-dependent properties. Some simple examples are presented to illustrate the procedure and output of the algorithm. (C) 2018 Elsevier Inc. All rights reserved.

关键词： Tubular networks Circle packing algorithms Connection algorithms depth-first search algorithm

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Design and Implement of the Complex Maze Shortest Path Simulation System Based On Improved Ant Colony Optimization algorithm 4

Design and Implement of the Complex Maze Shortest Path Simul...

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4th International Conference on Instrumentation and Measurement, Computer, Communication and Control (IMCCC)

作者： Zhang, Rongrong Yang, Ming Wang, Fang Southwest Univ Comp & Informat Sci Fac Chongqing 400715 Peoples R China

ISBN: (纸本)9781479965755

In artificial intelligence field, dynamic optimization problem under uncertain environment has always been a main topic and been widely researched these years. How to find the optimal solution around the goals to be solved is the key problem. As a typical case of uncertainty environment, maze has an important research value. In this paper we design a complex maze of random scene simulation system based on depth-first search algorithm. In the simulation system, the improved ant colony algorithm is used to find the shortest path connected maze entrance to maze exit to simulate the optimization problem in real-world. The process of how to find the shortest path dynamically of ants is displayed in this designed system and the whole behaviors of ant colony can be reflected.

关键词： complex maze generation depth-first search algorithm the shortest path ant colony algorithm

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Event-Based Summarization Using Critical Temporal Event Term Chain

Event-Based Summarization Using Critical Temporal Event Term...

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22nd International Conference on Computer Processing of Oriental Languages

作者： Liu, Maofu Li, Wenjie Zhang, Xiaolong Zhang, Ji Wuhan Univ Sci & Technol Coll Comp Sci & Technol Wuhan Peoples R China Hong Kong Polytech Univ Dept Comp Kowloon Peoples R China

ISBN: (纸本)9783642008306

In this paper, we investigate whether temporal relations among event terms can help improve event-based summarization and text cohesion of final summaries. By connecting event terms with happens-before relations, we build a temporal event term graph for source documents. The event terms in the critical temporal event term chain identified from the maximal weakly connected component are used to evaluate the sentences in source documents. The most significant sentences are included in final summaries. Experiments conducted on the DUC 2001 corpus show that event-based summarization using the critical temporal event term chain is able to organize final summaries in a more coherent way and make improvement over the well-known if*idf-based and PageRank-based summarization approaches.

关键词： Event-Based Summarization Event Term Graph Temporal Event Term Chain depth-first search algorithm

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Construction of Scalable 2-D Multi-Weight Optical Orthogonal Codes for Optical CDMA Networks

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IEICE TRANSACTIONS ON COMMUNICATIONS 2008年第12期E91B卷 3990-3993页

作者： Piao, Yong-Chun Choe, Jinwoo Sung, Wonjin Shin, Dong-Joon Hanyang Univ Dept Elect & Comp Engn Seoul 133791 South Korea Sogang Univ Dept Elect Engn Seoul South Korea

In this letter, we propose combinatorial and search construction methods of 2-D multi-weight optical orthogonal codes (OOCs) with autocorrelation 0 and crosscorrelation 1, called multi-weight single or no pulse per row (MSNPR) codes. An upper bound on the size of MSNPR codes is derived and the performance of MSNPR codes is compared to those of other OOCs in terms of the bit error rate (BER) and evaluated using blocking probability. It is also demonstrated that the MSNPR codes can be flexibly constructed for different applications, providing the scalability to optical CDMA networks.

关键词： OCDMA 2-D optical orthogonal codes packing design depth-first search algorithm network scalability

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Internetové uživatelské rozhraní pro tvorbu elektronických schémat

Internetové uživatelské rozhraní pro tvorbu elektronick...

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作者： Popelka, Lukáš Brno University of Technology

Diplomová práce pojednává o tvorbě editoru elektrických schémat pracujícím pod webovým rozhranním. Editor generuje textový zápis schématu, tzv. netlist... 详细信息

Diplomová práce pojednává o tvorbě editoru elektrických schémat pracujícím pod webovým rozhranním. Editor generuje textový zápis schématu, tzv. netlist kompatibilní s prostředím Spice. Program je vytvořen v programovacím jazyku Java a využívá tak možnosti objektově orientovaného programování. Editor je umístěn na webových stránkách a spustitelný jako aplet. Práce se soustředí na výběr vhodného programovacího jazyka, návrh programu a jeho realizaci. Obsahem práce jsou také ukázky programového kódu, oken programu a schématických značek součástek. Přiřazení čísel uzlů součástek probíhá dodatečně a to až v případě požadavku na generování netlistu ze strany uživatele. Pro přiřazení čísel uzlů je použit algoritmus hledání do hloubky. Generovaný textový zápis netlistu součástek probíhá podle konvence uvedené v referenční příručce programu OrCAD PSpice.

关键词： Java objektově orientované programování netlist Spice algoritmus hledání do hloubky Java object-oriented programming netlist Spice depth-first search algorithm Text

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