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Algebra has made the tasks of modelling routing algorithms and proving their correct operation very clear. However, traditional models are only concerned with the convergence to a stable routing solution not covering distributed hop-by-hop forwarding on multiple paths (within a flow or separately per flow). This paper addresses this challenge. Currently, loop-free distributed multipath forwarding is only proven if a strict decrease in the preference of a path occurs with every added link. This is very rigid for multipath routing, limiting the amount of equal preferred paths. In this work we prove that correct distributed forwarding behaviour is possible, without the strict decrease in preference, if the possible pairs of policy values applied to the directed edges connecting two nodes obey to a particular condition. If this is not true, correct behaviour is still possible if the policies applied to links forming circuits in the network graph are constrained according to two other conditions. Modern technologies are bringing the possibility to build new routing protocols using network programmability while distributed operation is still needed in many scenarios due to scaling issues. We show how our results can be relevant in this setting and serve as a tool in the design process and/or for formal protocol verification. authorsversion epub_ahead_of_print

In this paper, we study a dual-hop wireless powered communication network (DH-WPCN), where the two-way communication between the users and the access point (AP) is assisted by a relay. Assuming a piece-wise linear energy harvesting (EH) model for the users and the relay, we investigate the problem of total throughput maximization for both amplify-and-forward (AF) and decode-and-forward (DF) relaying modes. To deal with the non-convexity of the throughput maximization problem, we apply the block coordinate descent (BCD) technique and alternately optimize different blocks of optimization variables until convergence is achieved. Numerical results demonstrate the substantial performance gain of the proposed scheme with piece-wise linear EH model as compared to the case with oversimplified linear EH model. This is due to the fact that our proposed scheme takes into consideration the saturation effect of practical EH circuits in optimizing the resource allocation.

In this paper, resource allocation is studied for a fully sustainable cooperative IoT network, in which a relay powered by renewable energy forwards data to a destination while charging multiple IoT nodes by radio-frequency (RF) signals. An optimal joint time and power allocation problem is formulated to maximize the long-term sum-throughput of IoT nodes, taking into consideration the bounded transmit power of IoT nodes, the stochastic characteristic of energy harvesting (EH) process, and dynamic wireless channel conditions. To solve the formulated problem, we analyze the time allocation for cooperative communications with EH, considering both data and energy dependency of the two hop transmissions in three cases with different network settings. Based on the analysis, we derive the closed-form solutions of optimal time and power allocation in a network with symmetric links. Then, we extend our solution to a general network with asymmetric links. By employing Lyapunov optimization, an online stochastic resource allocation algorithm is proposed to obtain the maximum network throughput. It has been shown that the proposed algorithm can achieve close-to-optimal network throughput while maintaining the stability of the system. Finally, extensive simulations validate the analysis and demonstrate the effectiveness of the proposed algorithm.

In this letter, we propose a dual-hop reconfigurable intelligent surface (RIS)-based free space optical and radio frequency (FSO-RF) communication system, where an RIS is utilized to improve the coverage and system performance. Taking both the atmospheric turbulence and pointing errors into consideration, we derive exact closed-form expressions for the outage probability and bit error rate (BER) in terms of the Meijer’s G-function, generalized hypergeometric function, and Marcum Q-function. Furthermore, to obtain the diversity order, an asymptotic outage analysis is also obtained. Finally, the correctness of the analytical results is verified by Monte-Carlo simulation results.

In recent years, wireless sensor networks experience the energy hole problem as the most critical issue due to the heavy data forwarding load on the proximate sensor nodes to the sink. The best known solution found by the current state-of-the-art approaches for the energy hole problem is the Mobile Sink (MS) strategy. However, allowing the MS to visit every node for data collection incurs high data delivery latency, which may not be feasible in delay-sensitive applications. Thus, in this paper, restricted mobile sink motion is considered, where the MS halts at a limited number of locations stated as sojourn locations and all nodes disseminate their data to the nearby sojourn locations. The data dissemination to the sojourn location is achieved via a cluster-based routing protocol which aims to preserve the sensor nodes’ energy to enhance the network lifetime. Furthermore, analogous to network lifetime, extending the coverage lifetime is of equal importance in many coverage sensitive applications of WSN. Thus, this article incorporates the coverage parameter to the proposed protocol in order to preserve the network coverage despite certain nodes die. Based on the sojourn locations, the proposed routing algorithm ensures that each cluster data is disseminated to the MS following the minimum hop path to limit the data delivery delay. Experimental results demonstrate the efficacy of the proposed protocol over several state-of-the-art protocols with respect to different metrics like network lifetime, coverage ratio, energy efficiency, packet delivery ratio, end-to-end delay, etc.

The distance vector-hop (DV-hop) is a typical localization algorithm. It estimates sensor nodes location through detecting the hop count between nodes. To enhance the positional precision, the weight is used to estimate position, and the conventional wisdom is that the more hop counts are, the smaller value of weight will be. However, there has been no clear mathematical model among positioning error, hop count, and weight. This paper constructs a mathematical model between the weights and hops and analyzes the convergence of this model. Finally, the genetic algorithm is used to solve this mathematical weighted DV-hop (MW-GADV-hop) positioning model, the simulation results illustrate that the model construction is logical, and the positioning error of the model converges to 1/4R.

Clustering is an effective way to increase network lifetime but it leads to formation of isolated nodes in the wireless sensor network. These isolated sensor nodes forward data directly to sink and consume more energy which significantly reduces the network lifetime. In this article, we present how to maximize the network lifetime through joint routing and resource allocation with isolated nodes technique (JR-IN) between cluster head and isolated nodes in a cognitive based wireless sensor networks. In JR-IN technique the network area is divided into different layers and cluster size is formulated in each layer such that the size of the cluster remains unequal when it moves towards sink. Hence the cluster size is lager in the outermost layer compared to the cluster size in the inner most layer. To avoid inter cluster collision, we proposed different fixed channel to all the cluster heads in the network. For the intra cluster communication, the cluster member (sensor nodes) will lease the spectrum from the cluster head and forward data to their respective cluster head using TDMA technique. The periodical data gathering of cluster heads and forwarding the data to one hop cluster head may tend to lose energy faster and dies out quickly. We also propose in the JR-IN technique, the isolated nodes in the layer will take charge as a cluster head node and utilizes the resource allocated to the respective cluster head and forward the data to next hop cluster head. Simulation result shows that JR-IN outperforms the existing techniques, maximizes network lifetime and throughput and reduces the end to end delay.

The vehicular ad hoc network (VANET) is a self-organized and decentralized wireless ad hoc network formed by the mobile vehicles on demand to communicate the traffic-related valuable information among the vehicles. The mobile vehicles work as a node because they use to either send or receive traffic-related information in the network. The vehicles can communicate within restricted distance but mobility nature causes they frequently switch from one network to another network topology; therefore, the links among the vehicles seldom vanish. Therefore, in the multi-hop VANET delivery of the messages at the anticipated destination is problematic. In this paper, a routing mechanism namely link reliability-based multi-hop directional location routing (MHDLR) has proposed to overcome the link vanish problem. The MHDLR decides a link reliability-based next-hop node to create a strongly durable path from the source to destination. In multi-hop VANET, the inter-vehicle distance directly impacts on the connectivity of the vehicles. Therefore, to estimate the link reliability of vehicles their inter-vehicle distance and relative velocity have considered. The geometry-based localization mechanism (G-BLM) has been proposed to estimate the inter-vehicle distance of the vehicles. The performance of MHDLR has estimated for routing metrics i.e. path vanish, message broadcasting time in the group, packet delivery ratio and throughput. The simulated outcomes of the proposed model MHDLR have shown, its performance is better as compared to the existing fuzzy-logic based directional location routing (FLDLR), directional location aided routing (D-LAR) and location aided routing (LAR) protocols.

Energy usage on nodes is still a hot topic among researchers on wireless sensor networks. This is due to the increasing technological development increasing information requirements and caused the occurrence of information exchange continuously without stopping and impact the decline of lifetime nodes. It takes more effort to manually change the energy source on nodes in the wireless sensor network. The solution to such problems is to use routing protocols such as Low Energy Adaptive Clustering Hierarchy (LEACH). The LEACH protocol works by grouping nodes and selecting the Cluster Head (CH) in charge of delivering data to the Base Station (BS). One of the disadvantage LEACH protocols, when nodes are far from the CH, will require a lot of energy for sending data to CH. One way to reduce the energy consumption of each node-far is to use multi-hop communication. In this research, we propose a multi-hop simulated annealing (MhSA-LEACH) with an algorithm developed from the LEACH protocol based on intra-cluster multi-hop communication. The selection of intermediate nodes in multi-hop protocol is done using Simulated Annealing (SA) algorithm on Traveling Salesman Problem (TSP). Therefore, the multi-hop nodes are selected based on the shortest distance and can only be skipped once by utilizing the probability theory, resulting in a more optimal node path. The proposed algorithm has been compared to the conventional LEACH protocol and the Multi-Hop Advance Heterogeneity-aware Energy Efficient (MAHEE) clustering algorithm using OMNeT++. The test results show the optimization of MhSA-LEACH on the number of packets received by BS or CH and the number of dead or alive nodes from LEACH and MAHEE protocols.

Background: A limited number of patients return to sport (RTS) after an anterior cruciate ligament reconstruction (ACLR) and patients who RTS have a relatively high risk for second ACL injury. The purpose of the current study was to compare the results of a test battery between patients who returned to the pre-injury level of sport (RTS group) and patients who did not (NO-RTS group).It was hypothesized that the RTS group showed better test results.Methods: Sixty-four patients (age 27.8 +/- 8.8 years) were included. The results of a multicomponent test battery (jump-landing task assessed with the Landing Error Scoring System (LESS), three hop tests, isokinetic strength test for quadriceps and hamstring) were compared between groups with a 2 x 2 ANOVA.Results: The RTS group showed a significantly lower LESS score (p = 0.010), significantly higher absolute scores on hop tests with both legs (injured leg: single leg hop test p = 0.013, triple leg hop test p = 0.024, side hop test p = 0.021: non-injured leg: single leg hop test p 0.011, triple leg hop test p = 0.023, side hop test p = 0.032) and significantly greater hamstring strength in the injured leg (p = 0.009 at 60 degrees/s, p = 0.012 at 180 degrees/s and p - 0.013 at 300 degrees/s). No differences in test results were identified between patients who sustained a second ACL injury and patients who did not.Conclusion: Patients after ACLR with better jump-landing patterns, hop performance and greater hamstring strength have greater likelihood for RTS. However, our findings show that RTS criteria fail to identify patients who are at risk for a second ACL injury. (C) 2020 The Author(s). Published by Elsevier B.V.

Heat-shock factor 1 (HSF1) regulates the transcriptional response to stress and controls expression of molecular chaperones required for cell survival. Here we report that HSF1 is regulated by the abundance of the Hsp70-Hsp90 organizing protein (Hop/STIP1). HSF1 levels were significantly reduced in Hop-depleted HEK293T cells. HSF1 transcriptional activity at the Hsp70 promoter, and binding of a biotinylated HSE oligonucleotide under both basal and heat-shock conditions were significantly reduced. Hop-depleted HEK293T cells were more sensitive to the HSF1 inhibitor KRIBB11 and showed reduced short-term proliferation, and reduced long-term survival under basal and heat-shock conditions. HSF1 nuclear localization was reduced in response to heat-shock and the nuclear staining pattern in Hop-depleted cells was punctate. Taken together, these data suggest that Hop regulates HSF1 function under both basal and stress conditions through a mechanism involving changes in levels, activity and subcellular localization, and coincides with reduced cellular fitness.

The network-on-chips (NoCs)-based communication architecture is a promising candidate for addressing communication bottlenecks in many-core processors and neural network processors. In this article, we consider the generalized fault-tolerance topology generation problem, where the link (physical channel) or switch failures can happen, for application-specific NoCs (ASNoCs). With a user-defined maximum number of faults, $K$ , we propose an integer linear programming (ILP)-based method to generate ASNoC topologies, which can tolerate at most $K$ faults in switches or links. Given the communication requirements between cores and their floorplan, we first propose a convex-cost-flow-based method to solve a core mapping (CM) problem for building connections between the cores and switches. Second, an ILP-based method is proposed to solve the routing path allocation (PA) problem, where $K+1$ switch-disjoint routing paths are allocated for every communication flow between the cores. Finally, to reduce switch sizes, we propose to share the switch ports for the connections between the cores and switches and formulate the port sharing problem as a clique-partitioning problem, which is solved by iteratively finding a set of the maximum cliques. Additionally, we propose an ILP-based method to simultaneously solve the CM and routing PA problems when only physical link failures are considered. The experimental results show that the power consumption of fault-tolerance topologies increases almost linearly with $K$ because of the routing path redundancy for fault tolerance. When both switch faults and link faults are considered, port sharing can reduce the average power consumption of fault-tolerance topologies with $K=1$ , $K=2$ , and $K=3$ by 18.08%, 28.88%, and 34.20%, respectively. When considering only the physical link faults, the experimental results show that compared to the fault-tolerant topology generation (FTTG) algorithm, the proposed method reduces power consumption and hop count by 10.58% and 6.25%, respectively; compared to the de Bruijn Digraph (DBG)-based method, the proposed method reduces power consumption and hop count by 21.72% and 9.35%, respectively.

Underwater sensor networks (UWSNs) have recently been regarded as a promising method to monitor and explore underwater environments. Reliable and efficient data transmission to Sink is one of most important concerns of UWSNs. In this letter, we propose an energy-efficient probabilistic depth-based routing (EEPDBR) for UWSNs, which is improved from traditional depth-based routing (DBR) algorithm. The key idea of EEPDBR algorithm is to design an improved probabilistic DBR algorithm for reliable underwater data reporting to any surface sonobuoy, which takes node's depth, residual energy, and forwarding number within its 2-hop neighborhood into account. Extensive simulation results verify that the proposed EEPDBR method can achieve higher packet delivery ratio and lower average delivery time, while saving energy consumption effectively comparing to existing methods.

The hop count matrices (HCMs) are very helpful in obtaining the location information of sensing nodes in Internet of Things (IoT). However, in some scenarios, the HCMs cannot be completely observed due to abnormal termination of the flooding process, or some of the entries are contaminated by false information in external malicious attacks. Therefore, it is very important to recover the missing HCMs. However, to the best of our knowledge, there is no specific algorithm used in the current research to recover the HCMs, which would cause the positioning accuracy to be seriously deteriorated. In this article, for the scenarios of the entries partially observed in the HCMs, the HCMs recovery schemes, namely, HCMR-NBC and HCMR-MC, are proposed. The former, HCMR-NBC, is to learn the internal relations of different sensing node pairs in the HCMs. It is a simple and fast approach which utilizes the feature with a single dimension to predict the missing hop count values between the sensing nodes. The latter, HCMR-MC, is to transform the problem of the matrices recovery to the one of matrices completion. Compared with the previous SVT and BLMC algorithms, the proposed algorithms have great advantages in terms of the reconstruction performance and the computation complexity.

In this paper, the authors consider an underlay multi-hop cognitive radio network with energy harvesting secondary nodes, where there is a cluster of secondary decode-and-forward relays in each hop. The secondary nodes have no separate energy source available with them, but wake up from idle mode to harvest energy from the primary signal with the time-switching protocol, and use it for transmitting/relaying using the peak interference constraint. In each cluster, a relay with maximum transmit power is selected except in the last one. In the last cluster, a relay which has a maximum signal-to-noise ratio (SNR) at the secondary destination is selected. Though the suggested scheme has low implementation complexity and requires very little channel estimation, its performance is close to that of a scheme in which the link with the best SNR is chosen in each hop (which requires a lot of channel estimation). Analytical expressions are derived for the end-to-end outage probability and throughput assuming Rayleigh faded channels. They show that it is important to optimise the time-switching parameter (fraction of time devoted to energy harvesting) and the number of hops. Simulations confirm the accuracy of the derived expressions.

Routing in large-scale computer networks today is built on hop-by-hop routing: packet headers specify the destination address and routers use internal forwarding tables to map addresses to next-hop ports. In this paper we take a new look at the scalability of this paradigm. We define a new model that reduces forwarding tables to sequential strings, which then lend themselves readily to an information-theoretical analysis. Contrary to previous work, our analysis is not of worst-case nature, but gives verifiable and realizable memory requirement characterizations even when subjected to concrete topologies and routing policies. We formulate the optimal address space design problem as the task to set node addresses in order to minimize certain network-wide entropy-related measures. We derive tight space bounds for many well-known graph families and we propose a simple heuristic to find optimal address spaces for general graphs. Our evaluations suggest that in structured graphs, including most practically important network topologies, significant memory savings can be attained by forwarding table compression over our optimized address spaces. According to our knowledge, our work is the first to bridge the gap between computer network scalability and information-theory.

Age-of-information (AoI) is a metric quantifying information freshness at the receiver. It captures the delay together with packet loss and packet generation rate. However, the existing literature focuses on average or peak AoI and neglects the complete distribution. In this letter, we consider a ${N}$ -hop network with time-invariant packet loss probabilities on each link. We derive closed form equations for the probability mass function of AoI. We verify our findings with simulations. Our results show that the performance indicators considered in the literature such as average or peak AoI may give misleading insights into the real AoI performance.

Gateway elimination in a LoRa network could highly reduce the network installation cost. However, LoRa end devices could not overcome many obstacles with only a point-to-point communication. Thus, this research implemented a multi-hop communication in a LoRa network. One or more LoRa end devices are placed between the source node and the destination node to act as relay nodes. A simple routing based on the packet length is configured to determine the packet transmission path. As the results, the designed multi-hop communication could improve packet success rate until 2,47 times in indoor environment. Whereas, the optimum delay time for multi-hop communication is 100 ms for each hop to produce high PRR and lowest RTT.

In order to solve the problem that the traditional DV-Hop location algorithm has a large error in locating unknown nodes, this paper proposes an improved DV-Hop algorithm based on dual communication radius. By adding a communication radius, the algorithm updates the minimum hop number obtained by the unknown node closer to the beacon node to a smaller hop value and keeps the minimum hop number information of unknown nodes farther away. This method reflects the gap between the actual distances in terms of hop number, which solves the problem of the large difference between the actual distances of the same hops to a certain extent. Therefore, it is more advantageous to estimate the more accurate average jump distance and can calculate the more precise distance between them and obtain the more precise coordinates of unknown nodes. MATLAB simulation results show that the improved algorithm based on dual communication radius DV-Hop can effectively reduce the location error and improve the location accuracy and stability compared with the traditional DV-Hop location algorithm.

Multi-hop wireless sensor networks are being implemented in various domains. The collected data are used to make important decisions for censorious infrastructures. Data are processed by a huge quantity of sensor nodes as well as handled on intermediate nodes which are known as hops on the way to the Base Station (BS) which performs the resolution accomplishing. Information have been collected from various sources and intermediate hopes will process and aggregate information. A malevolent opponent may interfere through the information via proposing extra node within the web infrastructure. There are chances to compromising the existing nodes. Malevolent Selective Forwarding attacks are most important protection problem toward the information forwarding within wireless sensor networks (WSN), as this might hinder broadcast of susceptible information as well as it reduces network throughput. Assuring data trustworthiness in this situation has been critical in support of accurate resolution accomplishing. Information provenance signifies a main aspect into analyzing the trustworthiness of wireless sensor data. In this paper we introduce a provenance based technique to determine the attack. Three phases are there in this scheme, detecting packet-loss in the first phase, second phase dealing with identifying attacked sensor node and isolating malevolent sensor node in the third phase. We have included the detailedanalysis of the investigational outcomes for showing the accurateness as well as effectiveness of the proposed system.

The Internet of Things (IoT) has developed rapidly in recent years where significant numbers of devices have been connected to the network and this will increase over the ensuing years. There is also a trend to shift the IoT topology from cloud computing to fog computing where computing logic is brought as nearest as possible to the sensors. One of the topologies that is commonly used in fog computing is the mesh network. In a mesh network, end point nodes/sensors are connected to other nodes with routing capabilities called routers, and these nodes are connected to gateways where the mesh can communicate with other meshes or clouds. In multi-gateway mesh networks, each gateway may have set of routers that is fully depended on the gateway to forward the data to the clouds. Mesh is a complex network structure and the overall performance of the networks can be affected by several issues, such as overload gateways, network latency and gateway failover. In this paper, we compare the ordinary Network Voronoi Diagram (NVD) with Hops Voronoi diagram (HVD) to distribute the gateway workload based on network hops; and extend these methods to identify the overlapped routers for gateway failover.

In the multi-hop wireless network, transmission control protocol (TCP) throughput stability and flow fairness performances are worsened due to slower flow convergence in the loss recovery phase and flat-rate reduction during the congestion control process. In this article, a combination of network-assisted and window utilization based congestion control approach, known as feedback assisted improved recovery + (FAIR+), is proposed to overcome TCP's limitations under multi-hop wireless networks. The proposed FAIR+ algorithm initiates the congestion control process based on the queue level notification of the relay node and trims down the sending rate based on TCP flow's utilization level. In the congestion recovery phase, the FAIR+ algorithm implements a newer window increment pattern that achieves a faster convergence rate than the existing RFC 6582 implementation. The throughput stability of the FAIR+ algorithm is validated using the duality model and multi-hop wireless simulation. The simulation results convincingly prove that the FAIR+ attains significant improvement in throughput, flow fairness, and end-to-end latency performance over the existing TCP variants (OQS, NRT, and Westwood).

The main objective of Internet of Things (IoT) is to connect almost all the devices anywhere and everywhere in the world. IoT network is heterogeneous in nature, hence routing the data packets in this network is a big challenge. Routing Protocol for Low Power Lossy Network (RPL), has been designed by Internet Engineering Task Force (IETF) for such type of network. The existing design of RPL Objective Function (OF) is insufficient to cover all the issues of IoT applications. In this paper, the proposed OFs designs using various routing metrics are used to enhance the performance of the IoT applications. The analysis for various scenarios for these designs shows that only traditional hop and Expected Transmission Count (ETX) routing parameters will not fit for the smart applications need. The routing metric selection according to the application requirement is the principal idea of the proposed design. Three metrics ETX, Content and Energy, single and combination with each other are used to enhance the design of objective function of RPL for IoT applications. The enhanced triggering technique is added in these designs for the improvement of RPL. This technique will eliminate the cumulative effect of the short-listen problem of default trickle timer. The result analysis done using Cooja simulator along with Contiki Operating System (OS) states that, all the designs are performing well in one or other manner than the traditional OF. Energy combined with Content (EC) and aggregation with Enhanced timer (EC_En_Timer) design gives better result for Packet Delivery Ratio (PDR) and Latency Delay (LD) as compared to default OF design. Residual Energy (RE) combined with ETX (EE) and conjunction with Enhanced timer (EE_En_Timer) design works well for energy consumption. Overhead is very less in RE and ETX design. Conversion time is reduced by almost 50% in an En_Timer design. Higher PDR and low delay values of EC and EC_En_Timer design encourages its use in health monitoring application where reliability is essential. Low energy consumption results of RE, EE and EE_En_Timer designs are comfortable for forest monitoring application, as energy is a crucial aspect. This comparative result outcome will help to fulfill the IoT application requirements.

New ways of managing hop sediments from brewing and fermentation of beer are constantly being sought and the existing ones improved as part of the circular economy. These wastes are not generated in large amounts, but the absence of their proper characteristics may lead to further processing errors. The study analyses the composting of hop waste under laboratory conditions and the effects of the biological activity of composts introduced into the soil. The study was carried out on two-hop sediments from two different technological stages of beer production: hot trub (HT) and spent hops (SH). Chemical, microbiological and biochemical analyses, as well as the assessment of phytotoxicity to Lepidium sativum L., were performed in the materials. The results proved that, due to their formation technology, the tested feedstocks are safe from an epidemiological point of view and are not a source of microbial contamination. Inhibitory properties for plant development were found for HT and it most likely results from the organic compound content. The mineral composition of hot trub does not exclude composting if its share in biomass is low. Spent hops (SH) were characterised by a significant total nitrogen content, which affected the composting process. Composting this sediment required the selection of substrates with a wide C:N ratio. The number of microorganisms inhabiting the analysed material was very diverse and varied depending on the type of sediments. The sample that contained the composted SH from dry hopping had a much larger number of microorganisms than the sample with HT from wet hopping.

The large varieties of hops and hop products used in the brewing industry. Various in the biochemical composition, individual approaches to the brewing technology of each hop product are required in order to obtain a high-quality beer with a characteristic bitter taste and aroma. The purpose of this work was to study the biochemical composition of pressed conical hops, pellets of hop type 90, type 45, ethanolic and CO2 extracts of hop of various varieties, and their influence on the quality of the finished beer. As a result of comprehensive research on hops and hop products of various varieties, using the modern biochemical methods were determined differences in their biochemical composition depend on the absolute values such parameters as the mass fraction of α-acids, b-acids and their composition, xanthohumol, general polyphenols, essential oils, the ratio of their valuable components of hops: b-acids to a-acids and also for quantity of general polyphenols, essential oils per unit of α-acids. Based on the results of the biochemical composition of hops and hop products were investigated their influence on the quality of beer and were determined their using in brewing.

This letter investigates millimetre wave (mmWave) backhaul network flow as affected by the interplay between deployment/topology, hardware architectures of the nodes and the number of hops while taking into account minimum demand per a node. The objective is to maximise the network flow, for a given deployment, based here on the Madrid-grid model. The optimisation problem firstly minimises the number of fibre-connected nodes to meet the hop-constraint, followed by the maximisation of flow to meet the constraints on the number of radiofrequency (RF) chains on the node and minimum demand. The results show that by minimising the number of hops, the network flow generally increases but requires a higher number of fibre-connected nodes, while, at the same time, the total number of RF chains in the network is reduced.

Diffusion obstacles in membranes have not been directly visualized because of fast membrane dynamics and the occurrence of subresolution molecular complexes. To understand the obstacle characteristics, mobility-based methods are often used as an indirect way of assessing the membrane structure. Molecular movement in biological plasma membranes is often characterized by anomalous diffusion, but the exact underlying mechanisms are still elusive. Imaging total internal reflection fluorescence correlation spectroscopy (ITIR-FCS) is a well-established mobility-based method that provides spatially resolved diffusion coefficient maps and is combined with FCS diffusion law analysis to examine subresolution membrane organization. In recent years, although FCS diffusion law analysis has been instrumental in providing new insights into the membrane structure below the optical diffraction limit, there are certain exceptions and anomalies that require further clarification. To this end, we correlate the membrane structural features imaged by atomic force microscopy (AFM) with the dynamics measured using ITIR-FCS. We perform ITIR-FCS measurements on supported lipid bilayers (SLBs) of various lipid compositions to characterize the anomalous diffusion of lipid molecules in distinct obstacle configurations, along with the high-resolution imaging of the membrane structures with AFM. Furthermore, we validate our experimental results by performing simulations on image grids with experimentally determined obstacle configurations. This study demonstrates that FCS diffusion law analysis is a powerful tool to determine membrane heterogeneities implied from dynamics measurements. Our results corroborate the commonly accepted interpretations of imaging FCS diffusion law analysis, and we show that exceptions happen when domains reach the percolation threshold in a biphasic membrane and a network of domains behaves rather like a meshwork, resulting in hop diffusion.

In most applications of Mobile Ad-hoc Networking and Wireless Sensor networks (WSNs), security and power consumption is a recurring problem which is very difficult to solve due to unpredictable behaviour, environmental changes and mobility of nodes. TERP is a Trust based Energy Routing Protocol that considers the energy conservation and security aspects of WSNs. It is an improved version of AODV and ensures low power consumption while adding a trust based system to the reactive nature of AODV. It also provides the solutions for the most basic attacks like node selfishness, spoofing, misbehaviour and packet sniffing. But black-hole attack, gray-hole attack, Sybil and wormhole attacks are yet to be addressed in the TERP. This paper provides a solution to detect and prevent the node misbehaviour and gray-hole attack. TERP identifies the node misbehaviour using direct and indirect trust recommendations received from neighbour nodes. The detection rate of misbehaving nodes is less during the initial life of the network. Therefore we propose a method that detects the node misbehaviour during the initial life by using a multi-hop acknowledgement system. The simulation results show that the proposed method performs well in detecting the gray-hole and node misbehaviour.

Terpene alcohols play an important role in hop aroma, and their stereostructure is closely correlated with aroma characteristics. The stereoisomer distributions among R-(−)- and S-(+)-linalool, ner...

Interpretable multi-hop reading comprehension (RC) over multiple documents is a challenging problem because it demands reasoning over multiple information sources and explaining the answer prediction by providing supporting evidences. In this paper, we propose an effective and interpretable Select, Answer and Explain (SAE) system to solve the multi-document RC problem. Our system first filters out answer-unrelated documents and thus reduce the amount of distraction information. This is achieved by a document classifier trained with a novel pairwise learning-to-rank loss. The selected answer-related documents are then input to a model to jointly predict the answer and supporting sentences. The model is optimized with a multi-task learning objective on both token level for answer prediction and sentence level for supporting sentences prediction, together with an attention-based interaction between these two tasks. Evaluated on HotpotQA, a challenging multi-hop RC data set, the proposed SAE system achieves top competitive performance in distractor setting compared to other existing systems on the leaderboard., Comment: Accepted to AAAI 2020

The current article is concerned with the instability of 2-methylbutyl isobutyrate (2-MBIB) throughout beer storage. 2-MBIB is the primary ester of hops and HS-SPME-GC-MS/MS analysis of 135 commerc...

In multi-tree-structured Peer-to-Peer (P2P) video streaming, video streams are delivered from the source peer to subscribing peers in such a way that each stream is divided into several sub-streams and those sub-streams are delivered through different spanning trees. In this paper, we focus on the delivery of all sub-streams to [Formula: see text] subscribers through spanning trees of depth two each, which will be referred to as the 2-hop delivery of sub-streams. The main contribution of the current paper is the derivation of a tight lower bound on the upload capacity of homogeneous peers so that 2-hop delivery is possible if and only if the upload capacity of each peer is greater than or equal to the derived bound.

Hardware impairment is common in practical transceivers. This work analyzes the impact of hardware impairment on the performance of dual-hop relaying. In the analysis, both multiplicative I/Q imbalance and additive hardware impairment are considered at all nodes. The outage probabilities of amplify-and-forward (AF) and decode-and-forward (DF) relaying schemes are derived. The AF scheme includes both fixed-gain AF and variable-gain AF. Optimum maximum likelihood detectors are obtained. Numerical results are presented to show the effects of hardware impairment on relaying performances.

In infrastructure-less ad-hoc networks, the nodes can converse directly with other nodes without centralized servers. The vehicular networks are derived from the features of mobile ad-hoc networks (MANETs) whereas the message transmissions between the nodes are direct with each other or through some fixed terminals. But, a unique trademark is that the vehicle-to-vehicle ad-hoc links are poor because of extreme mobility which leads to frequent route breakage that causes emergency message delivery failure. The routing protocols availed in MANETS does not suit due to quick topology changes. The hop selection is based on the best cumulative communication duration that will be failing in some cases. Also, the worst/average case scenario is that the minimum connectivity to the source vehicle is not described in existing approaches. The core idea about the proposed research is to deliver data through an optimum path and to eliminate rupture link during the packet transmission. The system uses the Heterogeneous Motion Guess (HMG) algorithm for vehicular networks to set up a vested path. The HMG will select the relay vehicle's current position is near to the target vehicle plus the vehicle will opt the relay forwarder that has good radio coverage. The link lifetime of the selected hop should be greater than the minimum connectivity duration with the source vehicle. The selected vehicle will append the link expiry time and minimum connectivity duration in Route Demand Dispatch message in a unicast manner. This approach significantly minimizes the hop count numbers and improves the stability of the path. It radically predicts the link life, so the node can decide an alternative vested route. The simulation result shows how well the reactive demand-based HMG affords optimum results in terms of packet transmission success rate, average minimum hop counts, and communication delay.

The Pacific Northwest grows the majority of hops in the United States; however, the region is experiencing an increase in the number of days with high heat. In addition, there is an increased interest in growing hops in other warmer regions of the United States. To understand how hop plants respond to high temperatures, we measured several physiological traits of six hop cultivars under a range of temperatures from 15 to 45 °C. We found that hop plants achieved maximal carbon assimilation at temperatures of 21 to 39 °C when given sufficient water. At temperatures of 41 °C and higher, all cultivars experienced declines in carbon assimilation. This was likely due to multiple effects on the cell, including damage to photosystem II (PSII), as reflected in declines in FV/FM, damage to membrane integrity as reflected in electrolyte leakage at high temperatures, and declines in Rubisco activity likely due to degradation of Rubisco activase, as reflected in declines in Vc,max. ‘Cascade’, ‘Willamette’, and ‘Southern Brewer’ may be good candidates for growing in warm climates because all experience relatively high rates of carbon assimilation at high temperatures and did not experience significant declines in FV/FM or increases in electrolyte leakage. ‘Chinook’ appeared susceptible to extreme heat stress and exhibited evidence of irreparable damage to PSII and membrane integrity at 45 °C.

In hop-based burst-cluster transmission, multiple bursts are assembled simultaneously and sorted from the smallest number of hops to the largest one. By doing so, the burst loss probability for a large number of hops decreases, improving fairness. How- ever, in mesh networks, the amount of trac on each link is not necessarily the same, and hence degrades the performance of hop-based burst-cluster transmis- sion. In this paper, we propose dynamic burst or- dering to solve this problem. Here, each source node calculates the burst loss probability for each number of hops using ACK and NACK messages. Based on the calculated probabilities, the source node changes the order of bursts within a burst-cluster dynami- cally. It is expected that this method can improve local fairness for each source node. We evaluate the performance of the proposed method in tandem net- works by simulation. Numerical examples show that the proposed method is eective for improving fair- ness for each source node regardless of the amount of trac on each link.

Localization of sensor nodes is of utmost importance as the information collected by sensor nodes may be meaningless without the knowledge of its origin. Due to limited battery life and non uniform data loaded in the network, some of the sensor nodes may exhaust their battery early and may cease their intended function. This may lead to partitioning of network, wherein some portion of network may not communicate its sensed data to the sink node. In such situation we need to deploy some additional new nodes in the network. Newly deployed nodes needs to be localized as they are unaware of their estimated location. In this paper, we have proposed a new framework to localize newly deployed nodes in a pre-localized network using GA DV-Hop algorithm. The proposed framework has been simulated for various network topologies such as Random topology, C-shaped topology and W-shaped topology. Simulation results show that our proposed localization framework has a trade off between localization error and energy consumption, i.e. one of the proposed method features high localization accuracy at the cost of high energy consumption. However, it has been observed that proposed methods requires less time for localization as compared to traditional methods.

The upper bound capacity based on the SINR model is a very important parameter when evaluating the performance of the multi-hop wireless ad hoc networks. In this paper, a new upper bound capacity algorithm is proposed. Firstly, we analyzed the classical physics SINR model over the Rayleigh fading channels to establish the relationship between density of nodes and path outage probability. Then, we developed the closed-form expression of the upper bound transmission capacity based on the Weber model for the random networks. Finally, we evaluated effects of parameters in the communication range, density, SINR threshold and fading factors, and consequently transmission capacity of the network by sensitivity analysis. The numerical simulation showed that the optimum density of nodes was existed to obtain the upper bound transmission capacity. The capacity increased firstly and then decreased over the density of nodes increasing. It affected by channel fading factor and communication range sensitively.

The importance of hops (the flowers of Humulus lupulus) as food and an herbal remedy is reflected by a large number of analytical methods published. However, supercritical fluid chromatography, a highly efficient, rapid, and “green” separation technique, has not been considered for hops samples so far. This prompted us to establish the first supercritical fluid chromatography-based protocol for the separation, identification, and quantitation of five prenylated constituents of hops. Hulupinic acid (1), a prominent oxidation product of hop acids, three flavanones, i.e., 8-prenylnaringenin (2), 6-prenylnaringenin (3), and isoxanthohumol (4), as well as the chalcone xanthohumol (5) could be baseline separated in less than 5 minutes using a Viridis BEH 2-EP column (3.0 × 100 mm; 1.7 µm particle size) and a mobile phase consisting of CO2 and isopropanol. Good results regarding selectivity, accuracy (recovery rates: 85.0 – 113.1%), precision (intra-day ≤ 2.1%, inter-day ≤ 3.5%), and linearity (R2 ≥ 0.99) were obtained for both photodiode array and mass detection. The lowest detection limit at 220 nm was at 0.1 µg/mL (1, 3, and4), with mass detection even at 0.001 µg/mL (4). As an application example of the validated method, the five hops constituents were quantified in three dietary supplements, one herbal medicinal product, and two batches of hop flowers (Lupuli flos). In most samples analyzed, the major component was5 (0.01 – 1.02%), whereas the major component in Lupuli flos samples was compound1 (0.12 – 0.21%). This protocol offers a fast and environmentally friendly alternative to liquid chromatography for the quality control of hops.

A feasible and convenient strategy for oligosaccharide synthesis, which realizes reaction in solution while product purification occurs only by solid-liquid filtration, has been developed. By using a hop-on/off carrier (polytetrafluoroethylene particle), rapid synthesis of tumor-associated antigen Globo-H hexasaccharide has been successfully achieved within 5 steps in 48% overall yield without any intermediate purification by column chromatography. Also, global deprotection, including the cleavage of the tag, proceeded simultaneously only by one-step hydrogenolysis.

Efficient routing and broadcasting among a set of nodes play a critical role in wireless adhoc networks. for energy efficient routing, a connected dominating set (CDS) based virtual backbone is a promising approach. In the network, one-hop neighbors are selected as multi point relay (MPR) by each node to cover all its two-hop neighbors for the purpose of broadcasting and 2-hop repair. To improve the network lifetime, energy efficient MPR based CDS construction has been proposed by considering the node degree, energy level, node ID and velocity of the node. We also propose a route discovery protocol to relay route request messages, which makes use of the CDS nodes to obtain a stable routing path; 2-hop repair for route maintenance, which reduces the path damage (reduced control packets with lesser consumption of bandwidth) and broadcast storm problem. The simulation results show that the proposed protocol increases the network lifetime up to 30% than other works and effectively repair damaged routes by reducing control packets.

The selection of optimal relay node ever remains a stern challenge for underwater routing. Due to a rigid and uncouth underwater environment, the acoustic channel faces inevitable masses that tarnish the transmission cycle. None of the protocols can cover all routing issues; therefore, designing underwater routing protocol demands a cognitive coverage that cannot be accomplished without meticulous research. An angle-based shrewd technique is being adopted to improve the data packet delivery, as well as revitalize the network lifespan. From source to destination, one complete cycle comprises three phases indeed; in the first phase, the eligibility of data packet belonging to the same transmission zone is litigated by Forwarder Hop Angle (FHA) and Counterpart Hop Angle (CHA). If FHA value is equal or greater than CHA, it presages that the generated packet belongs to the same transmission zone; otherwise, it portends that packet is maverick from other sectors. The second phase picks out the best relay node by computing a three-state link quality with prefix values using the Additive-Rise and Additive-Fall method. Finally, the third phase renders a decisive solution regarding exorbitant overhead fistula; a packet holding time is contemplated to prevent the packet loss probability. Simulation results using NS2 have been analyzed, regarding packet delivery ratio, packet error rate, communication overhead, and end-to-end delay. Comparing to HHVBF and GEDAR, USPF indeed has outperformed, leading into the evidence of applicability’s favor.

Currently, IEEE 802.11 standard for ad-hoc wireless mode is inadequate for multi-hop network. Recent efforts for the advancement of 802.11 standards, such as 11e for QoS support and 11n for high data rates (> 100 Mbps), are still limited as they are dependent on the wired infrastructure backbone and single-hop wireless communication. One major challenge in quality-of-service (QoS) oriented routing in wireless ad-hoc networks is to find a route that satisfies multiple constraints including energy consumption minimization, delay, node failure and throughput maximization. In this paper, we propose a novel Dynamic Energy Efficient Routing (DEER) protocol that guarantees message delivery, maximum network lifetime and message flow. DEER uses those specific nodes on the fly which has maximum residual energy above a defined energy level for relaying message from a source to a destination. Our proposed approach has been evaluated using realistic channel model and it demonstrates improved session lifetime and efficient data flow compared to Probabilistic Energy Profile, Efficient Hop Count Routing, Dijkstra and Random/opportunistic algorithms. In addition, DEER can lend itself easily to battery-based sensor networks or energy-harvested based sensor networks.

The seamless data delivery is essential in VANET for application such as autonomous vehicle, intelligent traffic management and for the road safety and emergency applications. The incorporation of named data networking (NDN) with VANET, intended to frame intelligent traffic flow and seamless data delivery. Such integration of vehicular ad hoc networks (VANET) with NDN is termed as vehicular named data networks (VNDN). Because of the continuous node/vehicle mobility, it is a tedious process to build constant and consistent communication between vehicles. With that concern, for enhancing the performance of VNDN and solving the issues such as frequent cluster formation on heavy loaded data transmissions, position-based adaptive clustering model (PACM) is developed. The major intention of PACM is to form clusters based on trajectory. Besides, PACM performs efficient data caching by collecting significant data from vehicles to establish consistent data communication with all nodes in the network. Efficient data caching is done with the elected cluster heads among the framed clusters based on its positions and mobility models. For handling the vehicles at higher mobility speed, mutual data caching process is also designed that makes vehicles to perform on-demand data gathering from cluster heads. Further, the model is simulated and the obtained results are compared with the existing models based on the metrics such as packet delivery ratio, mean delay, cache hit rate and mean hop distance. The comparative analysis shows that the proposed model outperforms the available techniques.

Now-a-days, wireless sensor node acts as a basement for a higher level industrial internet of things application. Any kind of real time IoT applications sense the data using already in-built sensors. In real time physical environment, sensors are having minimum amount of power for their operations such as sensing, communicating and processing the data. Many researches are carried out to improve the energy efficiency of sensor nodes and improves their network lifetime. More concentration is needed on clustering and routing part of the communication to go for energy saving. We have proposed an algorithm based on fuzzy and unequal clustering (FBUCA) and a three tier multi-hop optimized routing technique (TM-ORT) to improve the efficiency of the network. Energy consumption and data reliability are stabilized by QOS based multi-hop routing protocols. Whenever clustering plays a main role, load balancing among the clusters has to be important to concentrate. Load balancing has been achieved by choosing best parameters for fuzzy based clustering to select an efficient cluster head for data aggregation and routing. We have done experimental simulations and concluded the results in terms of performance metrics such as standard deviation (SD), First node Die (FND), total energy consumption (TEC) and average energy consumption (AEC).

Routing in network is a classic issue to be solved. To route the data among the nodes without any interruptions and without getting yield in any kind of malicious attack is a tedious task. Though there exist many routing techniques which were near success in the past some part of the problems are always left unsolved. Trust-based routing techniques and the bio-inspired path is connecting techniques area embedded together to solve this. The security of the proposed technique is given a big significance, which takes care of the rest of the key points. Initially, when a node tries to enter into the network which was already secured and confined by trustable nodes, we provide a two-way security check both from the new node and from the host node. This is made possible by applying digital signature algorithm, hash message authentication code, and message-digest algorithms for signature generations, hash value generation, and its corresponding encrypt and decrypt procedure. Elliptic curve Diffie–Hellman algorithm is used for certificate verification, after which the node is provided with the broadcast key. In the case of routing, ant colony optimization is applied to detect the best path for routing from root to destiny, and this path is again verified by trust frameworks and certain calculations. This highly secured verification and authentication process make the proposed advanced resilient data consigning mechanism (ARDC) stand out from the existing routing mechanisms. The proposed ARDC mechanism is analyzed against various network frameworks as throughput, packet loss, overhead, delivery ratio, delivery latency, and hop count and path reliability to prove its effectiveness. Further, the routing capability is also analyzed by comparing it against traditional DSR, destination-sequenced distance-vector and open shortest path first protocols.

Low-voltage broadband power line communication (PLC) system transmits its information by the power line on the existed infrastructure. However, PLC attenuation and its harsh environment make it difficult to establish a reliable communication between the source and destination nodes, and relay-aided (RA) PLC technology can be used to solve this issue to increase the transmission rate and coverage. In this study, an indoor three-hop RA PLC system is under investigation for the first time. Based on a simple PLC attenuation model, the optimal relay node positions and transmitted power distribution of each node are studied to get the best system performance in theory. Then, a criterion of selection optimal relay node positions in a practical power-line network is derived by solving an optimisation problem. Finally, for a specific power-line network, the criterion for the selection of optimal relay node positions at the existed sockets between the source and destination nodes is verified. The theoretical work in this study could be useful in the design of broadband multi-hop RA PLC systems and their engineering applications.

Distance vector-hop (DV-hop) is a classical node localisation method for wireless sensor networks. Its main advantages are ease of use and excellent scalability, but its shortcomings are also very prominent for the high requirements on the network topology and low localisation accuracy in practical applications. An amended DV-hop strategy is provided to improve the shortcomings of the classical DV-hop including two aspects: one is that an N-gram model is adopted to amend the distances between unknown nodes and beacons and the other is that a weighed Levenberg–Marquardt method is adopted to optimise the unknown nodes’ initial positions. Simulation results show that compared with the original DV-hop method and the other two typical improved methods, our proposed strategy improves the adaptability of the DV-hop class methods to network topology changes, and the localisation accuracy is significantly enhanced.