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A multi-agent deep reinforcement learning approach for solving the multi-depot vehicle routing problem

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Journal of Management Analytics 2023年第3期10卷 493-515页

作者： Ali Arishi krishna krishnan Department of Industrial Engineering King Khalid UniversityAbhaSaudi Arabia Department of Industrial Systemsand Manufacturing EngineeringWichita State UniversityWichitaKSUSA

The multi-depot vehicle routing problem(MDVRP)is one of the most essential and useful variants of the traditional vehicle routing problem(VRP)in supply chain management(SCM)and logistics *** supply chains(SC)choose the joint distribution of multiple depots to cut transportation costs and delivery ***,the ability to deliver quality and fast solutions for MDVRP remains a challenging *** optimization approaches in operation research(OR)may not be practical to solve MDVRP in *** the latest developments in artificial intelligence(AI),it becomes feasible to apply deep reinforcement learning(DRL)for solving combinatorial routing *** paper proposes a new multi-agent deep reinforcement learning(MADRL)model to solve *** experiments are conducted to evaluate the performance of the proposed *** show that the developed MADRL model can rapidly capture relative information embedded in graphs and effectively produce quality solutions in real-time.

关键词： artificial intelligence supply chain management combinatorial optimization multi-depot vehicle routing problem multi-agent deep reinforcement learning

Steady rotation of a composite sphere in a concentric spherical cavity

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Acta Mechanica Sinica 2012年第3期28卷 653-658页

作者： D.Srinivasacharya M.krishna Prasad Department of Mathematics National Institute of Technology

The problem of steady rotation of a composite sphere located at the centre of a spherical container has been investigated. A composite particle referred to in this paper is a spherical solid core covered with a permeable spherical shell. The Brinkman＇s model for the flow inside the compos- ite sphere and the Stokes equation for the flow in the spheri- cal container were used to study the motion. The torque ex- perienced by the porous spherical particle in the presence of cavity is obtained. The wall correction factor is calculated. In the limiting cases, the analytical solution describing the torque for a porous sphere and for a solid sphere in an un- bounded medium are obtained from the present analysis.

关键词： Rotation Porous sphere Solid core Stokesflow Brinkman equation Stress jump coefficient. Torque Wall correction factor

Assessment of temporal dynamics of snow cover and its validation with hydro-meteorological data in parts of Chenab Basin, western Himalayas

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Science China Earth Sciences 2016年第5期59卷 1081-1094页

作者： Retinder KOUR Nilanchal PATEL Akhouri Pramod krishna Department of Remote Sensing Birla Institute of Technology Mesra

The present investigation was conducted to analyze the temporal patterns of snow cover area%(SCA%), air temperature, snowfall and river discharge in parts of Chenab basin, western Himalayas. The relationship of mean SCA% with mean air temperature and river discharge was also tested using Pearson's product-moment correlation at 95% confidence limit and further sensitivity analysis of river discharge to SCA and SCA to air temperature was performed. Moderate Resolution Imaging Spectroradiometer(MODIS) 8-day surface reflectance product MOD09A1 was used to delineate SCA during the period 2000–2013. Moreover, variation in the lowest elevation from where snow cover area starts(LESCA) was also analyzed and its relationship with mean air temperature was also studied. Non-parametric method, Mann-Kendall test was employed to determine the trend in the SCA%, air temperature, snowfall and river discharge. The investigation carried out for three meteorological stations i.e. Batote, Reasi and Tandi revealed significant findings. At Batote and Reasi, statistically significant decreasing trends were observed over the period 2000 to 2012, for maximum, minimum and mean air temperature. Mean minimum SCA% exhibited a significant upward trend during 2000–2013 which is corroborated by the significantly increasing trend of mean annual snowfall(Tandi station) from 2000 to 2010. Further, significant decreasing trend of river discharge for the winter season at Batote station from 2000 to 2011 and decreasing trends in the maximum, minimum and mean air temperature at Batote and Reasi stations are also consistent with the increasing trend of SCA%. At both Batote and Reasi stations, mean SCA% exhibited significant negative relationship with the mean air temperature. On the other hand, LESCA exhibited positive correlation with the mean air temperature except in a few months, where negative relationship was seen. Sensitivity analysis of river discharge to SCA exhibited very low values of sensitivit

关键词： Chenab basin SCA Mann-Kendall test MODIS Western Himalayas Sensitivity analysis

A new four-dimensional chaotic system with first Lyapunov exponent of about 22,hyperbolic curve and circular paraboloid types of equilibria and its switching synchronization by an adaptive global integral sliding mode control

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Chinese Physics B 2018年第4期27卷 214-227页

作者： Jay Prakash Singh Binoy krishna Roy Zhouchao Wei Department of Electrical Engineering National Institute of Technology Silchar Silchar 788010 India School of Mathematics and Physics China University of Geosciences Wuhan 430074 China

This paper presents a new four-dimensional（4 D） autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional（3 D） and 4 D chaotic *** proposed system exhibits hyperbolic curve and circular paraboloid types of *** system has all zero eigenvalues for a particular case of an equilibrium *** system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and *** system also exhibits coexistence of *** behavior of the new system is validated using circuit *** an interesting switching synchronization phenomenon is proposed for the new chaotic *** adaptive global integral sliding mode control is designed for the switching synchronization of the proposed *** the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization *** of the controller designed in the paper is compared with an existing controller.

关键词： new hyperchaotic system maximum chaos an infinite number of equilibria hidden attractors switching synchronization global sliding mode control

View on Bay of Bengal upwelling area on the basis of 19-years of satellite sea surface temperature

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International Journal of Digital Earth 2008年第3期1卷 304-314页

作者： K.Muni krishna Department of Meteorology and Oceanography Andhra University Visakhapatnam-530003India

The seasonal and interannual variation of upwelling along the east coast of India between 68N and 228N was studied for the period 19852003 using NOAAAVHRR sea surface temperature *** seasonal migration of pronounced upwelling,which follows the seasonal shift of the winds in transition period and northeast monsoon,was *** temporal mean sea surface temperature images clearly show the upwelling season,as does the seasonal sea surface temperature *** dominant features of the upwelling system are also the most variable,with most of the variance being explained by the seasonal ***-cyclic behaviour of sea surface temperature on interannual scales has also been observed.

关键词： AVHRR sea surface temperature seasonal interannual

ETM-IoT:Energy-Aware Threshold Model for Heterogeneous Communication in the Internet of Things

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Computers, Materials & Continua 2022年第1期70卷 1815-1827页

作者： A.Vijaya krishna A.Anny Leema School of Computer Science and Engineering VIT UniversityVelloreTamilnaduIndia School of Information Technology and Engineering VIT UniversityVelloreTamilnaduIndia

The internet of things(IoT)has a wide variety of applications,which in turn raisesmany challenging *** technology enables devices to closely monitor their environment,providing context-aware intelligence based on the real-time data collected by their sensor *** IoT not only controls these devices but also monitors their user’s *** of the major issues related to IoT is the need for an energy-efficient communication protocol which uses the heterogeneity and diversity of the objects connected through the *** energy consumption is a requirement for energyconstrained nodes and outsourced *** IoT nodes deployed in different geographical regions typically have different energy *** paper focuses on creating an energy-efficient protocol for IoTwhich can deal with the clustering of nodes and the cluster head selection *** energy thresholdmodel is developed to select the appropriate cluster heads and also to ensure uniform distribution of energy to those heads andmember *** proposed model envisages an IoT network with three different types of nodes,described here as advanced,intermediate and normal *** nodes are first-level nodes,which have the lowest energy use;intermediate nodes are second-level nodes,which have a medium energy requirement;and the advanced class are thirdlevel nodes with the highest energy *** simulation results demonstrate that the proposed algorithm outperforms other existing *** tests,it shows a 26%improvement in network lifetime compared with existing algorithms.

关键词： Internet of things communication energy threshold heterogeneous network

Local Extreme Complete Trio Pattern for Multimedia Image Retrieval System

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International Journal of Automation and computing 2016年第5期13卷 457-467页

作者： Santosh Kumar Vipparthi Shyam krishna Nagar Indian Institute of Technology Banaras Hindu UniversityVaranasi 221005Uttar PradeshIndia Malaviya National Institute of Technology Jaipur 302017RajastanIndia

This paper presents a new feature descriptor, namely local extreme complete trio pattern （LECTP） for image retrieval application. The LECTP extracts complete extreme to minimal edge information in all possible directions using trio values. The LECTP integrates the local extreme sign trio patterns （LESTP） with magnitude local operator （MLOP） for image retrieval. The performance of the LECTP is tested by conducting three experiments on Corel-5 000, Corel-10 000 and MIT-VisTex color databases, respectively. The results after investigation show a significant improvement in terms of average retrieval precision （ARP） and average retrieval rate （ARR） as compared to the other state-of-the art techniques in content based image retrieval （CBIR）.

关键词： Image retrieval (IR) local binary patterns (LBP) average retrieval precision (ARP) average retrieval rate (ARR) database (DB).

Roughness evaluation in shotcrete-lined water tunnels with invert concrete based on cases from Nepal

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Journal of Rock Mechanics and geotechnical Engineering 2018年第1期10卷 42-59页

作者： Chhatra Bahadur Basnet krishna Kanta Panthi Department of geosciences and Petroleum Norwegian University of Science and Technology

Most of the existing roughness estimation methods for water tunnels are related to either unlined or concrete/steel-lined tunnels. With the improvement in shotcrete technology, advancement in tunneling equipment and cost and time effectiveness, future water tunnels built for hydropower projects will consist of rock support with the extensive use of shotcrete lining in combination with systematic bolting and concrete lining in the tunnel invert. However, very little research has been performed to find out tunnel surface roughness for shotcrete-lined tunnels with invert concrete, which is important in calculating overall head loss along the waterway system to achieve an optimum and economic hydropower plant design. Hence, the main aim of this article is to review prevailing methods available to calculate tunnel wall roughness, and to use existing methods of head loss calculation to back-calculate roughness of the shotcrete-lined tunnels with invert concrete by exploiting measured head loss and actual cross-sectional profiles of two headrace tunnels from Nepal. Furthermore, the article aims to establish a link between the Manning coefficient and the physical roughness of the shotcrete-lined tunnel with invert concrete and to establish a link between over-break thickness and physical roughness. Attempts are also made to find a correlation between over-break thickness and rock mass quality described by Q-system and discussions are conducted on the potential cost savings that can be made if concrete lining is replaced by shotcrete lining with invert concrete.

关键词： Shotcrete-lined water tunnels Friction loss Physical and hydraulic roughnesses Tunnel over-break

Evaluation of earthquake impact on magnitude of the minimum principal stress along a shotcrete lined pressure tunnel in Nepal

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Journal of Rock Mechanics and geotechnical Engineering 2019年第5期11卷 920-934页

作者： krishna Kanta Panthi Chhatra Bahadur Basnet Department of Ceoscience and Petroleum Norwegian University of Science and Technology

In situ stress condition in rock mass is influenced by both tectonic activity and geological environment such as faulting and shearing in the rock *** influence is of significance in the Himalayan region,where the tectonic movement is active,resulting in periodic dynamic *** large-scale earthquake causes both accumulation and sudden release of strain energy,instigating changes in the in situ stress environment in the rock *** paper first highlights the importance of the magnitude of the minimum principal stress in the design of unlined or shotcrete lined pressure tunnel as water conveyance system used for hydropower *** we evaluated the influence of local shear faults on the magnitude of the minimum principal stress along the shotcrete lined high pressure tunnel of Upper Tamakoshi Hydroelectric Project(UTHP)in Nepal.A detailed assessment of the in situ stress state is carried out using both measured data and three-dimensional(3D)numerical analyses with ***,analysis is carried out on the possible changes in the magnitude of the minimum principal stress in the rock mass caused by seismic movement(dynamic loading).A permanent change in the stress state at and nearby the area of shear zones along the tunnel alignment is found to be an eminent process.

关键词： Shotcrete lined pressure tunnel The minimum principal stress Three-dimensional(3D)numerical model geology Tectonic activity Himalaya