Radial propagation of yield-power-law grouts into water-saturated homogeneous fractures
انتشار شعاعی ماسه های عملکردقدرت -قانون در شکستگی های همگن اشباع شده با آب-2020
This study presents analytical solutions for single-phase radial flow of yield-power-law fluids between homogeneous fractures (smooth parallel plates), which covers the special cases of yield-power-law fluids, i.e., Herschel-Bulkley, Bingham and power-law fluids, as well as Newtonian fluids. The analytical solution for radial flow of Herschel-Bulkley fluids is given for the first time. A formula for the plug flow region created by the yield stress is deduced, showing that this is constant and independent of the radius for radial flow of yield-stress fluids, which is also verified by numerical simulations. For modeling of the rock grouting process where the yieldpower- law grouts are injected into water-saturated fractures, we also established a general mathematical model for the two-phase (one yield-power-law grout and one Newtonian fluid) radial flow in homogeneous fractures using the Reynolds equation based on the derived analytical solutions for single-phase radial flow of yield-power-law grouts. By solving the two-phase radial flow problem, the evolution of pressure distribution and grout propagation length is illustrated. The results generally show the high sensitivity of the rheological parameters and the potentially important impact of water flow and time-dependent rheological properties on the radial propagation of yield power-law grouts.
Keywords: Rock grouting | Two-phase flow | Radial flow | Yield-power-law fluids | Plug flow region | Propagation length
The clustering algorithm for efficient energy management in mobile ad-hoc networks
الگوریتم خوشه بندی برای مدیریت انرژی کارآمد در شبکه های ad-hoc تلفن همراه-2020
MANET (Mobile Ad-hoc Network) consumes much energy due to their dynamic capabilities, complex- ities, constraints of design such as lack of a specified communication infrastructure, and their change over time. One strategy to reduce energy consumption is to optimize routing in these networks, which is, in turn, one of the most important challenges in these networks. In addition, optimal routing will in- crease the network lifetime and lead to its stability. Considering the high efficiency of clustering methods among the routing algorithms we present a new clustering method and considering good performance of Evolutionary Algorithms (EAs) in finding proper head clusters, we present a specific EA-based method named ICA (Imperialist Competitive Algorithm) via numerical coding. By thinking of specific conditions of a MANET and estimating the mobility direction of nodes, we prevent from additional reclusterings lead- ing to reducing the overload. We have evaluated our proposed method for: 1) accuracy (including the reproducibility, convergence and stability criteria) through three case studies with different numbers of nodes and ranges and 2) efficiency (by comparing to other methods). Moreover, we applied our proposed method to a case study (multi-robot system) with low velocity.
Keywords: ICA | MANET | Clustering | Energy consumption
Adaptive data and verified message disjoint security routing for gathering big data in energy harvesting networks
داده تطبیقی و تایید امنیت پیام متلاشی شدن مسیریابی برای جمع آوری داده های بزرگ در شبکه های برداشت انرژی-2020
To improve the data arrival ratio and the transmission delay and considering that the capacity for determining malicious nodes and energy are limited, a security disjoint routing-based verified message (SDRVM) scheme is proposed. The main contributions of SDRVM are as follows: (a) two connected dominating sets (a data CDS and a v-message CDS) are created for disseminating data and verified messages (v-messages), respectively, based on the remaining energy of nodes. (b) Nodes record the ID information in data packets with a specified probability, namely, the marking probability, which is adjusted according to the remaining energy of the nodes. (c) The duty cycle of the nodes is adjusted, and the energy of the nodes is divided into three levels. In the data CDS, the duty cycle of the sensor nodes is the longest and the duty cycle of the nodes that do not belong to either of the CDSs is the shortest. (d) If the energy of the sensor nodes is sufficient, data packets are transmitted several times and the v-messages that are stored in the nodes are transmitted to the destination nodes. The proposed scheme has been evaluated using different parameters where the results obtained prove its effectiveness in comparison to the existing solutions.
Keywords: Energy harvesting networks | Security | Disjoint routing | Marking probability | Network lifetime
AIS Data-Based for Statistics and Analysis of Maritime Traffic Dangerous Features: A Case Study of San Diego Costal Water
AIS مبتنی بر داده ها برای آمار و تجزیه و تحلیل ویژگی های خطرناک ترافیک دریایی: مطالعه موردی آب پایدار سن دیگو-2020
For analyzing the distribution characteristics of maritime traffic dangers and ensure the safety of ships navigating at sea, plotting the ship’s trajectory and making statistic based on the relevant dynamic data that can be extracted and analyzed from the Automatic Indentification System (AIS) information, the Distance to Closet Point of Approach (DCPA) between any two ships have been computed and applied. Through constructing the innovative three-dimensional bubbles chart to reflect the spatial characteristics from the DCPA matrix. Utilizing the Kernel Density Estimation (KDE) method, draws the heat map in the vicinity of San Diego sea area, measures the traffic danger characteristics of the costal sea area, and compares the analysis results with ArcGIS Pro 2.3. It reflects that the analysis results are consistent with the actual situation. The heat map has the powerful scientificity and practicability, can accurately measure the traffic distribution in the sea area, and provides auxiliary references for the planning and design of the ships routing system and maritime traffic safety management.
Key Words: Maritime Navigational Safety | Ship Automatic Identification System | Kernel Density Estimation | Distance to Closet Point of Approach
An energy-efficient distributed adaptive cooperative routing based on reinforcement learning in wireless multimedia sensor networks
مسیریابی همکاری تطبیقی با انرژی کارآمد و مبتنی بر یادگیری تقویتی در شبکه های حسگر چندرسانه ای بی سیم-2020
Complex task processing and frequent data communication in Wireless Multimedia Sensor Networks (WMSN) demand for energy-efficient and Quality of Service (QoS) guarantee to support new applications especially in the sensing layer of Internet-of-Vehicles. However, the WMSN is heterogeneous and the energy distribution is not uniform, the current routing protocols do not take energy consumption into account while ensuring QoS. Therefore, to make energy distribution more efficiently while ensuring QoS has become a challenging problem. In this paper, we propose an energy-efficient distributed adaptive cooperative routing (EDACR) for WMSN, taking into account the constraints of QoS and energy consumption. Particularly, we design a reinforcement learning based mechanism to perform QoS and energy balanced routing according to the knowledge of reliability and delay. The simulation results show that the energy consumption is reduced while ensuring QoS compared with the traditional cooperative protocol and the distributed adaptive cooperative routing protocol.
Keywords: WMSN | Adaptive | Cooperative routing | Reinforcement learning | QoS | Energy-efficient distributed
Reinforcement learning of adaptive online rescheduling timing and computing time allocation
یادگیری تقویت زمان بندی برنامه ریزی آنلاین انطباقی و تخصیص زمان محاسبات-2020
Mathematical optimization methods have been developed to a vast variety of complex problems in the field of process systems engineering (e.g., the scheduling of chemical batch processes). However, the use of these methods in online scheduling is hindered by the stochastic nature of the processes and prohibitively long solution times when optimized over long time horizons. The following questions are raised: When to trigger a rescheduling, how much computing resources to allocate, what optimization strategy to use, and how far ahead to schedule? We propose an approach where a reinforcement learning agent is trained to make the first two decisions (i.e., rescheduling timing and computing time allocation). Using neuroevolution of augmenting topologies (NEAT) as the reinforcement learning algorithm, the ap- proach yields, on average, better closed-loop solutions than conventional rescheduling methods on three out of four studied routing problems. We also reflect on expanding the agent’s decision-making to all four decisions.
Keywords: Online scheduling | Rescheduling procedures | Reinforcement learning | Decision-making | Timing | Computing resource allocation
Modeling dopaminergic modulation of clustered gamma rhythms
مدل سازی مدولاسیون دوپامینرژیک ریتم گاما خوشه ای-2020
Gamma rhythm (20–100 Hz) plays a key role in numerous cognitive tasks: working mem- ory, sensory processing and in routing of information across neural circuits. In compar- ison with lower frequency oscillations in the brain, gamma-rhythm associated firing of the individual neurons is sparse and the activity is locally distributed in the cortex. Such “weak”gamma rhythm results from synchronous firing of pyramidal neurons in an inter- play with the local inhibitory interneurons in a "pyramidal-interneuron gamma" or PING. Experimental evidence shows that individual pyramidal neurons during such oscillations tend to fire at rates below gamma, with the population showing clear gamma oscillations and synchrony. One possible way to describe such features is that this gamma oscilla- tion is generated within local synchronous neuronal clusters. The number of such syn- chronous clusters defines the overall coherence of the rhythm and its spatial structure. The number of clusters in turn depends on the properties of the synaptic coupling and the intrinsic properties of the constituent neurons. We previously showed that a slow spike frequency adaptation current in the pyramidal neurons can effectively control cluster numbers. These slow adaptation currents are modulated by endogenous brain neuromod- ulators such as dopamine, whose level is in turn related to cognitive task requirements. Hence we postulate that dopaminergic modulation can effectively control the clustering of weak gamma and its coherence. In this paper we study how dopaminergic modulation of the network and cell properties impacts the cluster formation process in a PING network model.
Keywords: Gamma oscillations | Spike frequency adaptation | Cluster syncronization | Dopamine modulation | Multiple timer scales
A Savings-Based Heuristic for Solving the Omnichannel Vehicle Routing Problem with Pick-up and Delivery
روش مکاشفه ای مبتنی بر ذخیره برای حل مسئله کانال مسیریابی وسایل نقلیه کانال omni با انتخاب و تحویل-2020
In recent times, new models of commerce have incorporated new decisions and constraints which have led to new variants of classical problems in supply chain management. Modern advances in Information and Communication Technologies have increased the number of marketing channels that are available to consumers. This paper focusses on the new “omnichannel” delivery concept for the retailing industry which addresses the replenishment of a set of retail stores and on the direct shipment of the products to customers (last-mile delivery) within an integrated VRP formulation. The VRP in omnichannel distribution systems consists of a group of retail stores that must be served from a distribution center and a set of online consumers that must be served by the same fleet of cargo vehicles from these retail stores. Since the VRP in omnichannel distribution systems is an NP-Hard problem, we propose a savings-based heuristic for solving large-size instances the VRP in omnichannel retailing. Results show that the proposed heuristic is able to find feasible and competitive solutions in a very short computational time.
Keywords: Vehicle Routing Problem | Omnichannel Supply Chain | Savings Heuristic
Managing underground transfer of floods for irrigation: A case study from the Ramganga basin, India
مدیریت انتقال زیرزمینی سیلاب برای آبیاری : یک مطالعه موردی از حوضه رامگانگا ، هند-2020
Protecting flood prone locations through floodwater recharge of the depleted aquifers and using it for protecting dry season irrigated agriculture is the rationale for a form of intervention termed as ‘underground transfer of floods for irrigation’ (UTFI). This helps reduce the intensity of seasonal floods by tapping and storing excess floodwater in aquifers for productive agricultural use. This paper presents a case study of managing the recharge interventions in the context of the Ramganga basin, India. Using a case study approach, this study determines the socio-economic and institutional context of the study area, proposes three potential routes to institutionalize UTFI, and provides insights for scaling up the interventions in the Ganges and other river basins that face seasonal floods and dry season water shortages. Managing the interventions involves community participation in regular operations and maintenance tasks. Given the limited scale of the pilot UTFI intervention implemented to date, and the socio-economic and institutional context of the case study region, the benefits are not conspicuous, though the piloting helped in identifying potential ways forward for the long-term management of the pilot site, and for scaling up the interventions. Initially pilot site management was handled by the project team working closely with the community leaders and villagers. As the intervention was demonstrated to perform effectively, management was handed over to the district authorities after providing appropriate training to the government personnel to manage the system and liaise with the local community to ensure the site is operated and managed appropriately. The district administration is willing to support UTFI by pooling money from different sources and routing them through the sub-district administration. While this is working in the short term, the paper outlines a programmatic longer term approach for wider replication.
Keywords: Floods | Droughts | Groundwater | Management | Institution | Ganges basin | India
An enhancement of EAACK using P2P ACK and RSA public key cryptography
افزایش EAACK با استفاده از رمزنگاری کلید عمومی P2P ACK و RSA-2019
MANET – Mobile Adhoc Network is a self-configuring network that connected by the number of mobile nodes with wireless links and it has no fixed infrastructure. In this, each single node can operates as both a transmitter and receiver. It has been exploited in various applications such as disaster stuck areas, military, emergency revival etc. Nevertheless, the open intermediate and broad distribution of nodes in MANET can cause a vulnerable to different malicious attacks and MANET that can operate consistently even in the being there of inside packet drop attackers can be really challenging. Therefore, we need to develop Intrusion Detection System to detect the misbehavior nodes during the packet delivery with acknowledgement for the protection of MANET. In this paper, EAACK (Enhanced Adaptive Acknowledgment) is developed with Enhanced Interior Gateway Routing Protocol (EIGRP) hybrid protocol which consists of P2P ACK and RSA algorithm. At present, the network overhead is caused by the digital signature algorithm if more misbehavior nodes are presented on network. Hence, this proposed system is applied with EIGRP to reduce the network overhead caused by digital signatures in EAACK, and P2P (peer-peer) ACK and RSA (named after Ron Rivest, Adi Shamir and Len Adleman) provides more security to the network. S-ACK (Selective Acknowledgements) cannot differentiate the particular node is malicious node. Therefore, this proposed system introduces the P2P ACK to detect the misbehavior node efficiently. Here, RSA can encrypt the session key that creates the key more secure to improve the security level and P2P ACK use this encrypted key for the acknowledgement. In the P2P ACK, keys are generated by the RSA and distributed for signing and verifying the acknowledgement packets in advance. This proposed P2P ACK is used to enhance the detection of misbehavior nodes. The performance of this proposed method can improve the security level and reduce the routing overhead through the secured acknowledgement.
Keywords: MANET | EAACK | Routing overhead | Security level | RSA | P2P ACK | Intrusion detection systems | Misbehaving nodes detec