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In the process of multi-target tracking, the complex underwater acoustic channel, target model mismatch, target strong maneuvering and other factors are easy to cause track interruption and rerun, which have a bad influence on the situation assessment and tactical decision of the Unmanned sonar system. Aiming at the problem of track interruption, this paper integrates the track adhesion algorithm into the active multi-target tracking algorithm. Simulation results show that the track adhesion algorithm can effectively improve the correct track association rate and track lifetime. By comparing the effect of the new and old methods with the sea test data, the track adhesion can effectively solve the problem of track interruption in the case of target track maneuvering and improve the track life.

Understanding long-term variations in aerosol loading is essential for evaluating the health and climate effects of airborne particulates as well as the effectiveness of pollution control policies. The expected satellite lifetime is about 10 to 15 years. Therefore, to study the variations of atmospheric constituents over longer periods information from different satellites must be utilized. Here we introduce a method to construct a combined annual and seasonal long time series of AOD at 550 nm using the Along-Track Scanning Radiometers (ATSR: ATSR-2 and AATSR combined) and the MODerate resolution Imaging Spectroradiometer on Terra (MODIS/Terra), which together cover the 1995–2017 period. The long-term (1995–2017) combined AOD time series are presented for all of mainland China, for southeastern (SE) China and for 10 selected regions in China. Linear regression was applied to the combined AOD time series constructed for individual L3 (1∘ × 1∘) pixels to estimate the AOD tendencies for two periods: 1995–2006 (P1) and 2011–2017 (P2), with respect to the changes in the emission reduction policies in China. During P1, the annually averaged AOD increased by 0.006 (or 2 % of the AOD averaged over the corresponding period) per year across all of mainland China, reflecting increasing emissions due to rapid economic development. In SE China, the annual AOD positive tendency in 1995–2006 was 0.014 (3 %) per year, reaching maxima (0.020, or 4 %, per year) in Shanghai and the Pearl River Delta regions. After 2011, during P2, AOD tendencies reversed across most of China with the annually averaged AOD decreasing by −0.015 (−6 %) per year in response to the effective reduction of the anthropogenic emissions of primary aerosols, SO2 and NOx. The strongest AOD decreases were observed in the Chengdu (−0.045, or −8 %, per year) and Zhengzhou (−0.046, or −9 %, per year) areas, while over the North China Plain and coastal areas the AOD decrease was lower than −0.03 (approximately −6 %) per year. In the less populated areas the AOD decrease was small. The AOD tendency varied by both season and region. The increase in the annually averaged AOD during P1 was mainly due to an increase in summer and autumn in SE China (0.020, or 4 %, and 0.016, or 4 %, per year, respectively), while during winter and spring the AOD actually decreased over most of China. The AOD negative tendencies during the 2011–2017 period were larger in summer than in other seasons over the whole of China (ca. −0.021, or −7 %, per year) and over SE China (ca. −0.048, or −9 %, per year). The long-term AOD variations presented here show a gradual decrease in the AOD after 2011 with an average reduction of 30 %–50 % between 2011 and 2017. The effect is more visible in the highly populated and industrialized regions in SE China, as expected.

The most important thing nowadays is to use available resources to develop infrastructure as efficiently as possible. In this regard, evaluating the deterioration of tramway tracks is critical from both a technical and an economic viewpoint. In Hungary, seven types of superstructure systems are currently differentiated in the case of tramway transport, but the geometrical deterioration, lifecycle, and lifecycle cost of the tramway tracks are not accurately known. The current study aimed to evaluate and compare the results of track geometry measurements of two different “open” tramway superstructure systems depending on their traffic load and age. The geometry measurements we re executed by TrackScan 4.01 instrument, developed and maintained by a Hungarian developer company called Metalelektro Méréstechnika Ltd. The evaluation of the measurements showed a clear relationship between the traffic load, age, and track deterioration. Based on the results, it can be generally stated, concerning “open” superstructure systems, that regardless of the “open” superstructure system or the level of traffic load, the average value of alignment is decreasing; however, the average value of the longitudinal level is increasing. Furthermore, the deterioration of an older ballasted track with lower traffic is similar to that of a younger ballasted track that has a higher traffic load. Another significant result was that the deterioration of the track gauge parameter in the case of concrete slab tracks is clearly described as the broadening of the track gauge.

Ethylene propylene diene monomer (EPDM) is broadly employed as an insulating material for high voltage applications. Surface discharge-induced thermal depolymerization and carbon tracking adversely affect its performance. This work reports the electrical field modeling, carbon tracking lifetime, infrared thermal distribution, and leakage current development on EPDM-based insulation with the addition of nano-BN (boron nitride) contents. Melt mixing and compression molding techniques were used for the fabrication of nanocomposites. An electrical tracking resistance test was carried out as per IEC-60587. Simulation results show that contamination significantly distorted the electrical field distribution and induced dry band arcing. Experimental results indicate that electric field stress was noticed significantly higher at the intersection of insulation and edges of the area of contamination. Moreover, the field substantially intensified with the increasing voltage levels. Experimental results show improved carbonized tracking lifetime with the addition of nano-BN contents. Furthermore, surface temperature was reduced in the critical contamination flow path. The third harmonic component in the leakage current declined with the increase of the nano-BN contents. It is concluded that addition of nano-BN imparts a better tracking failure time, and this is attributed to better thermal conductivity and thermal stability, as well as an improved shielding effect to electrical discharges on the surface of nanocomposite insulators.

In wireless sensor networks (WSN), sensor nodes communicate with one another and transfer the sensed data to the sink over a wireless medium, making the network vulnerable to a variety of security flaws, including eavesdropping. To provide a secure communication, encryption techniques based on some keys need to be used, and the participating sensor nodes should agree with it. The sensor nodes are resource constrained in terms of energy, memory, and processing power. As a result, the key agreement technique in WSN is nontrivial. Therefore, many key agreement techniques have been developed, however most of them focus primarily on security, which is not considered a relevant concern in the context of energy efficiency. There is a compromise between energy usage and security, so we've proposed an algorithm to address it. Also, the nodes in WSN can be benefited by using symmetric based pairwise key establishment for efficient communication in the network. The proposed algorithm strikes a crucial balance between secure routing and energy consumption within wireless sensor networks, outperforming well-established routing algorithms by delivering optimal results. In this paper, we have proposed a Secure and Energy Efficient Protocol Based on Pairwise Key (SEE2PK) for WSN. In the proposed scheme, nodes need to store only one row of the secure matrix and establish secure communication after exchanging one column of a public matrix, which is based on the neighbor adjacency matrix of a cluster. This scheme benefits from using a mesh router as a Cluster Head (CH) due to more memory and computation power. The storage and computation costs are decreased by employing the adjacency matrix as a public matrix. The performance of secure routing is examined with the standard techniques, and the results indicate that: 1) nodes can establish pairwise communication with other nodes; 2) performance of the proposed scheme is better for network metrics: network lifetime, security, computation cost, scalability, and energy consumption; 3) communication cost and storage cost of the network are decreased.

Severe damage to cement asphalt mortar (CA mortar) can compromise the stability and safety of high-speed railway operations due to various complex factors during service. The loads from high-speed trains and temperature gradients within the ballastless track structure are significant contributors to this damage. However, most previous studies have focused on laboratory tests or numerical simulations under simple loading conditions, while few have investigated the damage evolution of CA mortar when both train loads and temperature gradients are considered simultaneously. In this paper, a finite element model of the CRTS II ballast track and a high-speed railway train dynamics model based on the damage constitutive model of CA mortar was established. The damage evolution of CA mortar through long-term cyclic numerical simulations under the combined effects of train load and temperature gradient load were investigated. By integrating the maintenance criteria for high-speed railways, the lifetime of CA mortar using the criteria of crack length and off-seam width was predicted. In addition, the material and structural properties of CA mortar were also optimized, considering the relationship between its elastic modulus and density, to enhance its lifetime. The conclusions reached are more realistic. The results indicate that the combined load causes deformation in the ballast track structure, leading to gradual damage progression from the edge to the interior of the CA mortar layer. The lifetime of CA mortar is determined by the number of days it takes for the crack length to reach the maintenance criteria. The lifetime of CA mortar under different temperature gradients ranges from 1 to 2 years. Increasing the elastic modulus and thickness of the CA mortar layer improves its lifespan. An elastic modulus of 9000 MPa and a thickness of 50 mm for the CA mortar were recommended.

This paper describes a problem related to a casting bridge crane with a combined load of 200/50/12.5 t and a span of 18.6 m, working in a heavy metallurgical operation. Due to the specific stress of the structure after its long-term operation, longitudinal fillet welds between the upper flange and the web of the main box beam on the rail side of the 200 t trolley were irreparably damaged. As a result, the cross-section of the main beam had opened, thereby substantially reducing its strength and stiffness. This resulted in a disproportionate increase and undesirable redistribution of stresses in the beam and, at the same time, an increase in the probability of acute fatigue or the loss of stability of the elastic beam shape. Therefore, the rectification of the damaged load-bearing structure was carried out by specific structural modifications. Critical load-bearing elements were subjected to complicated strength and fatigue life analyses before and after rectification. These analyses were supported by experimental measurements. The applied modifications resulted in a partial strengthening of the lifting device with the possibility of its further operation, but only in a limited mode, with a limited period of operation with a time limit of 2 years and a reduced total load capacity of 150 t. The applied methods are also applicable for the fatigue analysis of load-bearing elements and equipment for bridge, gantry and tower cranes, crane tracks, road and railway bridges and support structures under machinery and other devices with a dominant transverse and rotating effect.

Here, this paper presents a search for direct electroweak gaugino or gluino pair production with a chargino nearly mass-degenerate with a stable neutralino. It is based on an integrated luminosity of 36.1 fb–1 of pp collisions at √s = 13 TeV collected by the ATLAS experiment at the LHC. The final state of interest is a disappearing track accompanied by at least one jet with high transverse momentum from initial-state radiation or by four jets from the gluino decay chain. The use of short track segments reconstructed from the innermost tracking layers significantly improves the sensitivity to short chargino lifetimes. The results are found to be consistent with Standard Model predictions. Exclusion limits are set at 95% confidence level on the mass of charginos and gluinos for different chargino lifetimes. For a pure wino with a lifetime of about 0.2 ns, chargino masses up to 460 GeV are excluded. For the strong production channel, gluino masses up to 1.65 TeV are excluded assuming a chargino mass of 460 GeV and lifetime of 0.2 ns.

In sensor network lot of difficulties are made for routing, so does not improve the network lifetime. Normal routing consumes more resources; it is not efficient approach for huge number of sensor nodes in network. Sender node not finds the all nodes location in particular time slot. Also heavy load given to the routing path provides unexploited routing path. Proposed Improved Network Lifetime to Identify Unexploited Path (ILIUP) is applied to network which increase lifetime of routing nodes. The main purpose of ILIUP is to discover the efficient path with uninterrupted packet forwarding process. The unexploited paths are detected based on its behavior, sender broadcast data packet continuously from source node to destination node through path that does not handle heavy load or traffic in network. Then develop the series cornerstone path algorithm to obtain series of intermediate node for relaying the data packets frequently, it tracks the each and every node position, easy to assign routing path. It reduces energy consumption, routing overhead, and increase network lifetime, Throughput.