The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform
Ruo-wei Hung - One of the best experts on this subject based on the ideXlab platform.
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The Longest (s, t)-paths of O-shaped Supergrid Graphs.
arXiv: Discrete Mathematics, 2019Co-Authors: Ruo-wei Hung, Fatemeh Keshavarz-kohjerdiAbstract:In this paper, we continue the study of the Hamiltonian and longest $(s, t)$-paths of supergrid graphs. The Hamiltonian $(s, t)$-path of a graph is a Hamiltonian path between any two given vertices $s$ and $t$ in the graph, and the longest $(s, t)$-path is a simple path with the maximum number of vertices from $s$ to $t$ in the graph. A graph holds Hamiltonian connected property if it contains a Hamiltonian $(s, t)$-path. These two problems are well-known NP-complete for general supergrid graphs. An $O$-shaped supergrid graph is a special kind of a rectangular grid graph with a rectangular hole. In this paper, we first prove the Hamiltonian connectivity of $O$-shaped supergrid graphs except few conditions. We then show that the longest $(s, t)$-path of an $O$-shaped supergrid graph can be computed in linear time. The Hamiltonian and longest $(s, t)$-paths of $O$-shaped supergrid graphs can be applied to compute the minimum trace of computerized embroidery machine and 3D printer when a hollow object is printed.
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Finding Hamiltonian and Longest (s, t)-paths of C-shaped Supergrid Graphs in Linear Time
arXiv: Computational Complexity, 2019Co-Authors: Ruo-wei Hung, Fatemeh Keshavarz-kohjerdiAbstract:A supergrid graph is a finite vertex-induced subgraph of the infinite graph whose vertex set consists of all points of the plane with integer coordinates and in which two vertices are adjacent if the difference of their x or y coordinates is not larger than 1. The Hamiltonian path (cycle) problem is to determine whether a graph contains a simple path (cycle) in which each vertex of the graph appears exactly once. This problem is NP-complete for general graphs and it is also NP-complete for general supergrid graphs. Despite the many applications of the problem, it is still open for many classes, including solid supergrid graphs and supergrid graphs with some holes. A graph is called Hamiltonian connected if it contains a Hamiltonian path between any two distinct vertices. In this paper, first we will study the Hamiltonian cycle property of C-shaped supergrid graphs, which are a special case of rectangular supergrid graphs with a rectangular hole. Next, we will show that C-shaped supergrid graphs are Hamiltonian connected except few conditions. Finally, we will compute a longest path between two distinct vertices in these graphs. The Hamiltonian connectivity of C-shaped supergrid graphs can be applied to compute the optimal stitching trace of computer embroidery machines, and construct the minimum printing trace of 3D printers with a C-like component being printed.
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The Hamiltonicity, Hamiltonian Connectivity, and Longest (s, t)-path of L-shaped Supergrid Graphs.
arXiv: Discrete Mathematics, 2019Co-Authors: Fatemeh Keshavarz-kohjerdi, Ruo-wei HungAbstract:Supergrid graphs contain grid graphs and triangular grid graphs as their subgraphs. The Hamiltonian cycle and path problems for general supergrid graphs were known to be NP-complete. A graph is called Hamiltonian if it contains a Hamiltonian cycle, and is said to be Hamiltonian connected if there exists a Hamiltonian path between any two distinct vertices in it. In this paper, we first prove that every L-shaped supergrid graph always contains a Hamiltonian cycle except one trivial condition. We then verify the Hamiltonian connectivity of L-shaped supergrid graphs except few conditions. The Hamiltonicity and Hamiltonian connectivity of L-shaped supergrid graphs can be applied to compute the minimum trace of computerized embroidery machine and 3D printer when a L-like object is printed. Finally, we present a linear-time algorithm to compute the longest (s, t)-path of L-shaped supergrid graph given two distinct vertices s and t.
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The Hamiltonian connectivity of rectangular supergrid graphs
Discrete Optimization, 2017Co-Authors: Ruo-wei Hung, Chin-feng Li, Jong-shin Chen, Qing-song SuAbstract:Abstract A Hamiltonian path of a graph is a simple path which visits each vertex of the graph exactly once. The Hamiltonian path problem is to determine whether a graph contains a Hamiltonian path. A graph is called Hamiltonian connected if there exists a Hamiltonian path between any two distinct vertices. In this paper, we will study the Hamiltonian connectivity of rectangular supergrid graphs. Supergrid graphs were first introduced by us and include grid graphs and triangular grid graphs as subgraphs. The Hamiltonian path problem for grid graphs and triangular grid graphs was known to be NP-complete. Recently, we have proved that the Hamiltonian path problem for supergrid graphs is also NP-complete. The Hamiltonian paths on supergrid graphs can be applied to compute the stitching traces of computer sewing machines. Rectangular supergrid graphs form a popular subclass of supergrid graphs, and they have strong structure. In this paper, we provide a constructive proof to show that rectangular supergrid graphs are Hamiltonian connected except one trivial forbidden condition. Based on the constructive proof, we present a linear-time algorithm to construct a longest path between any two given vertices in a rectangular supergrid graph.
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iCAST - The Hamiltonian connectivity of some alphabet supergrid graphs
2017 IEEE 8th International Conference on Awareness Science and Technology (iCAST), 2017Co-Authors: Ruo-wei Hung, Jun-lin LiAbstract:Supergrid graphs are first introduced by us and their structures are derived from grid and triangular-grid graphs. The Hamiltonian path problem on general supergrid graphs is a NP-complete problem. A graph is said to be Hamiltonian connected if a Hamiltonian path between any two nodes in it does exist. In the past, deciding whether or not a general supergrid graph contains a Hamiltonian path has been proved to be NP-complete. Very recently, we verified the Hamiltonian connectivity of some special supergrid graphs, including triangular, parallelogram, trapezoid, and rectangular supergrid graphs, except few conditions. In this paper, the Hamiltonian connectivity of alphabet supergrid graphs will be verifed. There are 26 types of alphabet supergrid graphs in which every capital letter is represented by a type of alphabet supergrid graphs. We will provide constructive proofs to verify the Hamiltonian connectivity of L-, F-, C-, and E-alphabet supergrid graphs. The results can be used to verify the Hamiltonian connectivity of other alphabet supergrid graphs with similar structure, such as G-, H-, J-, I-, O, P-, T-, S-, and U-alphabet supergrid graphs. The application of the Hamiltonian connectivity of alphabet supergrid graphs can be to compute the minimum stitching track of computer embroidery machines while a string is sewed into an object.
Bryan M. Jenkins - One of the best experts on this subject based on the ideXlab platform.
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SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?
Energy Policy, 2013Co-Authors: Morten Boje Blarke, Bryan M. JenkinsAbstract:This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two.
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SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?
Energy Policy, 2013Co-Authors: Morten Boje Blarke, Bryan M. JenkinsAbstract:This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two.The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit.The analysis includes a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments.A political effort is required for establishing dedicated SmartGrid innovation zones, while also redefining infrastructure to avoid the narrow focus on grids and cables. SmartGrid Investment Trusts could be supported from reallocation of planned transmission grid investments to provide for the equitable development of SmartGrid strategies. Compares SuperGrid and SmartGrid strategies for integrating intermittent renewables.Identifies technological and socio-economic conflicts of interest between the two.Proposes a strategic zoning strategy allowing for both strategies to evolve.Presents a paradigmatic case study showing that strategies are mutually exclusive.Proposes dedicated SmartGrid innovation zones and SmartGrid investment trusts. © 2013 Elsevier Ltd.
Burak Omer Saracoglu - One of the best experts on this subject based on the ideXlab platform.
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Location selection factors of concentrated solar power plant investments
Sustainable Energy Grids and Networks, 2020Co-Authors: Burak Omer SaracogluAbstract:Abstract This research aims to find, define, identify, describe, select and cluster (group, set) the location selection factors of very large concentrated solar power plant investments in Supergrids (super grid) and Global Grid with location selection factors module of the 1 s t generation Original Anatolian Honeybees’ investment decision support methodology. 11 preliminary screening investment stage criteria (e.g. C A : Direct normal irradiation/irradiance/insolation (DNI), C D : High-Voltage Direct Current (HVDC) & High-Voltage Alternating Current (HVAC) electrification/power grid infrastructure, C G : Political, war, terror & security conditions), and 287 pre-feasibility investment stage criteria (e.g. C B : Governments’ Supergrid integration policy, C B1 : Common Supergrid framework, legislation, and directive development willingness, C B2 : Common Supergrid electricity transmission law/regulation development willingness) are presented in a semantically clustered form by Grey Weighted Product Method based on expert judgments (3 linguistic variables in grey numbers and equal weight mean whitenization) weighting integrated with experience curve in select awarded criteria honeycomb cell, and Fuzzy Decision-Making Trial and Evaluation Laboratory combined with Simple Additive Weighting Method based on expert judgments (3 linguistic variables in triangular fuzzy membership functions, and graded mean integration defuzzification) weighting integrated with experience curve in complex clustering honeycomb cell. 11 criteria at only 1 hierarchical level (factors) and 287 criteria at 4 hierarchical levels (i.e. main factors, factors, 1st level sub-factor, 2nd level sub-factors) are semantically clustered respectively for preliminary screening and pre-feasibility project investment development stages.
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An Experimental Fuzzy Expert System Based Application For The Go/No-Go Decisions To The Geospatial Investigation Studies Of The Regions Of The Very Large Concentrated Solar Power Plants In The European Supergrid Concept
2018Co-Authors: Burak Omer SaracogluAbstract:One of the crucial activities of today's world electricity research groups is the investigation of the modeling possibility of the international grids on the concepts of the Supergrids and the Globalgrid. The European Supergrid Concept is one of the concepts in this respect. The solar power is one of the important renewable energy resource in the European Supergrid Concept. The concentrated solar power technology is one of the solar power technologies amongst the solar power technologies. The engineering, procuring, constructing and operating of the very large concentrated solar power plants in the European Supergrid Concept shall be one of the ways to escape from the consumption of fossil fuels. This paper performs an experimental one node Mamdani type fuzzy rule base evaluation approach or application for the go/no-go decisions to the geospatial investigation studies of the regions of the very large concentrated solar power plants in the European Supergrid Concept.
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Comparative Experimental FWA & FOWA Aggregated VLCSPPs' LUR Estimation for GIS Based VEED
International Journal of Engineering, 2018Co-Authors: Burak Omer SaracogluAbstract:Today, the solar power conversion technologies are the photovoltaics (PV), the concentrated solar power (CSP), and the concentrated photovoltaics (CPV). All of these technologies need sufficient amount of appropriate land. In the Supergrids and the Global Grid, the large sized power plants play the key role, so that this study only focuses on the very large solar power plants (VLSPP). The VLSPPs are defined as the power plants that have the installed power of 1.000 MW (peak in PV) or more in this study. There isn't any solar power plant in this size on the world by 2015. Hence, the solar land use requirements should be studied, analyzed and estimated for each solar power technology. This study investigates only the very large concentrated solar power plants (VLCSPPs). Under the unsharp conditions, a fuzzy weighted average/weight averaging (fuzzy WA) aggregated and an ordered fuzzy weighted average/weight averaging (fuzzy OWA) aggregated solar land use requirement models on worldwide basis are built for the land use requirement (LUR) prediction in the geospatial information system investigation studies (GIS) at the very early engineering design (VEED) phase. These two models are presented in a comparative way. Five experimental criteria (direct normal irradiance: DNI, engineering design year, net installed power, cooling method, storage capacity) are only included in these models. This study and its findings will be a good start to design a VLCSPP in the Supergrids and the Global Grid in the following few years.
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A framework for selecting the location of very large photovoltaic solar power plants on a global/supergrid
Energy Reports, 2018Co-Authors: Burak Omer Saracoglu, Opemipo E. Atiba, Jatinder Gill, Olayinka S. Ohunakin, Damola S Adelekan, Imhade P. Okokpujie, Aderemi A. AtayeroAbstract:One of the important optimization applications (minimization and maximization) is the power grid systems. National electricity grids should be interconnected to develop larger regional grids (Supergrids), and further integrated to build up a worldwide grid (global grid) for minimizing consumption of natural resources and maximizing economical useful life, recycling rate, and effective usage of natural resources. These Supergrids and global grid concepts can only be developed through detailed and organized supportive research studies. This research study aims to find, define, identify, describe and select location selection factors of very large photovoltaic solar power plant investments on a global grid and supergrid concepts. Grey systems theory, fuzzy (Type-1 and 2) theories, Mamdani's type fuzzy rule-based system, Interpretive Structural Modelling (ISM), Impact Matrix Cross-Reference Multiplication Applied to a Classification (MICMAC) tool, and Political, Economic, Social and Technological (PEST) framework and its extensions (SLEPT, PESTEL, PESTLE, STEEPLE, STEEPLED, DESTEP, STEER) are concurrently used in this study. Eleven (11) criteria are presented for preliminary screening (i.e. C 1 : global horizontal irradiation (GHI), C 2 : governments supergrid integration policy, C 3 : supergrid business climate and conditions, C 4 : High Voltage Direct Current (HVDC) and High Voltage Alternating Current (HVAC) electrification grid infrastructure, C 5 : land use, allocation and availability, C 6 : geological conditions, C 7 : political, war, terror & security, C 8 : topographical conditions, C 9 : climatic conditions, C 10 : water availability conditions, C 11 : natural disaster/hazard conditions), and 191 factors are presented for pre-feasibility investment stages. Findings can directly be used or taken as a basis for further analysis by researchers and practitioners.
Morten Boje Blarke - One of the best experts on this subject based on the ideXlab platform.
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SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?
Energy Policy, 2013Co-Authors: Morten Boje Blarke, Bryan M. JenkinsAbstract:This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two.
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SuperGrid or SmartGrid: Competing strategies for large-scale integration of intermittent renewables?
Energy Policy, 2013Co-Authors: Morten Boje Blarke, Bryan M. JenkinsAbstract:This paper defines and compares two strategies for integrating intermittent renewables: SuperGrid and SmartGrid. While conventional energy policy suggests that these strategies may be implemented alongside each other, the paper identifies significant technological and socio-economic conflicts of interest between the two.The article identifies differences between a domestic strategy for the integration of intermittent renewables, vis-à-vis the SmartGrid, and a cross-system strategy, vis-à-vis the SuperGrid. Policy makers and transmission system operators must understand the need for both strategies to evolve in parallel, but in different territories, or with strategic integration, avoiding for one strategy to undermine the feasibility of the other. A strategic zoning strategy is introduced from which attentive societies as well as the global community stand to benefit.The analysis includes a paradigmatic case study from West Denmark which supports the hypothesis that these strategies are mutually exclusive. The case study shows that increasing cross-system transmission capacity jeopardizes the feasibility of SmartGrid technology investments.A political effort is required for establishing dedicated SmartGrid innovation zones, while also redefining infrastructure to avoid the narrow focus on grids and cables. SmartGrid Investment Trusts could be supported from reallocation of planned transmission grid investments to provide for the equitable development of SmartGrid strategies. Compares SuperGrid and SmartGrid strategies for integrating intermittent renewables.Identifies technological and socio-economic conflicts of interest between the two.Proposes a strategic zoning strategy allowing for both strategies to evolve.Presents a paradigmatic case study showing that strategies are mutually exclusive.Proposes dedicated SmartGrid innovation zones and SmartGrid investment trusts. © 2013 Elsevier Ltd.
Fatemeh Keshavarz-kohjerdi - One of the best experts on this subject based on the ideXlab platform.
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The Longest (s, t)-paths of O-shaped Supergrid Graphs.
arXiv: Discrete Mathematics, 2019Co-Authors: Ruo-wei Hung, Fatemeh Keshavarz-kohjerdiAbstract:In this paper, we continue the study of the Hamiltonian and longest $(s, t)$-paths of supergrid graphs. The Hamiltonian $(s, t)$-path of a graph is a Hamiltonian path between any two given vertices $s$ and $t$ in the graph, and the longest $(s, t)$-path is a simple path with the maximum number of vertices from $s$ to $t$ in the graph. A graph holds Hamiltonian connected property if it contains a Hamiltonian $(s, t)$-path. These two problems are well-known NP-complete for general supergrid graphs. An $O$-shaped supergrid graph is a special kind of a rectangular grid graph with a rectangular hole. In this paper, we first prove the Hamiltonian connectivity of $O$-shaped supergrid graphs except few conditions. We then show that the longest $(s, t)$-path of an $O$-shaped supergrid graph can be computed in linear time. The Hamiltonian and longest $(s, t)$-paths of $O$-shaped supergrid graphs can be applied to compute the minimum trace of computerized embroidery machine and 3D printer when a hollow object is printed.
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Finding Hamiltonian and Longest (s, t)-paths of C-shaped Supergrid Graphs in Linear Time
arXiv: Computational Complexity, 2019Co-Authors: Ruo-wei Hung, Fatemeh Keshavarz-kohjerdiAbstract:A supergrid graph is a finite vertex-induced subgraph of the infinite graph whose vertex set consists of all points of the plane with integer coordinates and in which two vertices are adjacent if the difference of their x or y coordinates is not larger than 1. The Hamiltonian path (cycle) problem is to determine whether a graph contains a simple path (cycle) in which each vertex of the graph appears exactly once. This problem is NP-complete for general graphs and it is also NP-complete for general supergrid graphs. Despite the many applications of the problem, it is still open for many classes, including solid supergrid graphs and supergrid graphs with some holes. A graph is called Hamiltonian connected if it contains a Hamiltonian path between any two distinct vertices. In this paper, first we will study the Hamiltonian cycle property of C-shaped supergrid graphs, which are a special case of rectangular supergrid graphs with a rectangular hole. Next, we will show that C-shaped supergrid graphs are Hamiltonian connected except few conditions. Finally, we will compute a longest path between two distinct vertices in these graphs. The Hamiltonian connectivity of C-shaped supergrid graphs can be applied to compute the optimal stitching trace of computer embroidery machines, and construct the minimum printing trace of 3D printers with a C-like component being printed.
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The Hamiltonicity, Hamiltonian Connectivity, and Longest (s, t)-path of L-shaped Supergrid Graphs.
arXiv: Discrete Mathematics, 2019Co-Authors: Fatemeh Keshavarz-kohjerdi, Ruo-wei HungAbstract:Supergrid graphs contain grid graphs and triangular grid graphs as their subgraphs. The Hamiltonian cycle and path problems for general supergrid graphs were known to be NP-complete. A graph is called Hamiltonian if it contains a Hamiltonian cycle, and is said to be Hamiltonian connected if there exists a Hamiltonian path between any two distinct vertices in it. In this paper, we first prove that every L-shaped supergrid graph always contains a Hamiltonian cycle except one trivial condition. We then verify the Hamiltonian connectivity of L-shaped supergrid graphs except few conditions. The Hamiltonicity and Hamiltonian connectivity of L-shaped supergrid graphs can be applied to compute the minimum trace of computerized embroidery machine and 3D printer when a L-like object is printed. Finally, we present a linear-time algorithm to compute the longest (s, t)-path of L-shaped supergrid graph given two distinct vertices s and t.