Parameterized algorithms of fundamental NP-hard problems: a survey

Li, Wenjun; Ding, Yang; Yang, Yongjie; Sherratt, R. Simon; Park, Jong Hyuk; Wang, Jin

doi:10.1186/s13673-020-00226-w

Cited by 64 publications

(46 citation statements)

References 125 publications

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“…In all types of hybrid perovskites, divalent metallic cations form a BX 6 octahedral with halogen anions [43][44][45][46][47][48][49][50][51][52][53][54][55][56]. Most of the electronic and optical properties of hybrid perovskites depend on the BX 6 framework [57][58][59][60][61][62][63][64][65][66][67][68][69][70]. These materials are found in an orthorhombic phase at low temperatures (space group: Pnma) [71][72][73][74][75][76][77][78][79][80][81][82][83][84].…”

Section: Introductionmentioning

confidence: 99%

RETRACTED: The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites

et al. 2021

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Hybrid inorganic perovskites (HIPs) have been developed in recent years as new high-efficiency semiconductors with a wide range of uses in various optoelectronic applications such as solar cells and light-emitting diodes (LEDs). In this work, we used a first-principles theoretical study to investigate the effects of phase transition on the electronic and optical properties of CsPbI3 pure inorganic perovskites. The results showed that at temperatures over 300 °C, the structure of CsPbI3 exhibits a cube phase (pm3m) with no tilt of PbI6 octahedra (distortion index = 0 and bond angle variance = 0). As the temperature decreases (approximately to room temperature), the PbI6 octahedra is tilted, and the distortion index and bond angle variance increase. Around room temperature, the CsPbI3 structure enters an orthorhombic phase with two tilts PbI6 octahedra. It was found that changing the halogens in all structures reduces the volume of PbI6 octahedra. The tilted PbI6 octahedra causes the distribution of interactions to vary drastically, which leads to a change in band gap energy. This is the main reason for the red and blue shifts in the absorption spectrum of CsPbI3. In general, it can be said that the origin of all changes in the structural, electronic, and optical properties of HIPs is the changes in the volume, orientation, and distortion index of PbI6 octahedra.

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Section: Introductionmentioning

confidence: 99%

RETRACTED: The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites

et al. 2021

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“…The MP problem is a mixed-integer nonlinear programming problem (MINLP), which is an NP-hard problem [24,25]. It is very hard to figure out the precise optimal solution of this kind of problem.…”

Section: Problem Formulationmentioning

confidence: 99%

“…First contact Event Intervals [25,35]sec Simulation time 21600sec As depicted in Fig. 9, b0 is the event generator, which represents the data collection point.…”

Section: Routing Protocolmentioning

confidence: 99%

Revenue Optimization of a UAV-Fog Collaborative Framework for Remote Data Collection Services

Luo

Wang

et al. 2020

IEEE Access

Self Cite

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Unmanned aerial vehicles (UAVs) can provide remote data collection services with quality of service guarantees. The typical application fields include geographic information systems, such as topological survey and natural disasters and hazards monitoring. In the bad geographic environment, wireless communication performance of UAVs cannot be guaranteed. Therefore, the efficiency of remote data collection cannot be guaranteed. This paper proposes a collaborative framework of UAVs and fog computing for remote data collection. Our goal is to maximize the revenue of UAVs with the support of fog computing, so we need to find the optimal computation resources allocation and task assignment scheme. This is a mixed integer nonlinear programming problem. The block coordinate descent method is used to solve this problem, which allows the original problem to be divided into the optimal task assignment subproblem and the optimal computation resource allocation sub-problem. The greedy algorithm, heuristic algorithm and brute force algorithm are proposed to solve the optimal task assignment sub-problem. The convex optimization analysis method is used to solve the optimal resource allocation sub-problem. The genetic algorithm is used as a benchmark to compare with the heuristic-based block coordinate descent algorithm. The numerical simulation and network simulator based-simulation results show that the proposed UAV-Fog collaborative data collection problem can be efficiently solved by the block coordinate descent algorithm based on the heuristic strategy.

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“…Studies also show that the largest consumers of natural resources are development projects. In addition, various national and international programs are underway with an incentive to encourage developers and state-owned companies to move towards green, and in some cases to specify in its application [42,[58][59][60]. In the present article, while focusing on the environmental approach in the sustainable development of construction projects, green construction is presented as its main part and its implementation solutions are proposed.…”

Section: Introductionmentioning

confidence: 99%

Hotel Construction Management considering Sustainability Architecture and Environmental Issues

Kadaei

Sadeghian

Majidi

et al. 2021

Shock and Vibration

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Sustainable development and environment in the activities of the construction industry has attracted the attention of experts in most countries of the world. One of the obvious and problematic features of the construction industry of countries is the use of modern building materials using traditional construction methods. Changing the paradigm for sustainable buildings requires a change in the architectural design process. Today, smart buildings are buildings that are at a lower level in terms of energy consumption and operate in a dynamic and integrated environment, creating a perfect harmony between management, system, services, and structure. These qualities make plastics ideal products for construction and an essential component for a sustainable built environment. In the design of smart and sustainable buildings, the use of environmentally friendly materials increases the lifespan of the building and an effective step is taken towards the design of sustainable architecture. In this paper, we evaluate hotel construction based on sustainability issues with MCDM. The results show that alternative A4 is the best alternative in sustainable issues. With the increasing population and its concentration in large cities, the concern of energy supply and energy efficiency in buildings is one of the main concerns of urban planners, officials, and city residents. Construction projects mainly consume large amounts of materials and leave a huge amount of waste, and this problem sometimes includes existing buildings that cannot be demolished and need to be rebuilt and maintained.

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Parameterized algorithms of fundamental NP-hard problems: a survey

Cited by 64 publications

References 125 publications

RETRACTED: The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites

RETRACTED: The Effect of Structural Phase Transitions on Electronic and Optical Properties of CsPbI3 Pure Inorganic Perovskites

Revenue Optimization of a UAV-Fog Collaborative Framework for Remote Data Collection Services

Hotel Construction Management considering Sustainability Architecture and Environmental Issues

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