Long-term tracking based on spatio-temporal context

Aiming at the problem that the fast tracking algorithm using spatio-temporal context (STC) will inevitably lead to drift and even lose the target in long-term tracking, a new algorithm based on spatio-temporal context that integrates long-term tracking with detecting is proposed in this paper. We track the target by the fast tracking algorithm, and the cascaded search strategy is introduced to the detecting part to relocate the target if the fast tracking fails. To a large extent, the proposed algorithm effectively improves the accuracy and stability of long-term tracking. Extensive experimental results on benchmark datasets show that the proposed algorithm can accurately track and relocate the target though the target is partially or completely occluded or reappears after being out of the scene.     

Efficient clustering and simulated annealing approach for circuit partitioning

Circuit net list bipartitioning using simulated annealing technique has been proposed in the paper. The method converges asymptotically and probabilistically to global optimization. The circuit net list is partitioned into two partitions such that the number of interconnections between the partitions is minimized. The proposed method begins with an innovative clustering technique to obtain a good initial solution. Results obtained show the versatility of the proposed method in solving non polynomial hard problems of circuit net list partitioning and show an improvement over those available in literature.     

Study on bending conditions of plate in coil box

In a coil box between the roughing and finishing stands on a hot strip mill, a problem has been encountered that the entry region of the plate touches the bending rolls and deforms. As a result, the defective coil occurs. The condition of plate bending, which forms a new deformation feature in coiling, is analyzed. In this paper, the authors focus on the research of the effects of coiling parameters, such as the thickness of plate, roll speed and feeding speed of plate in coil box, and on specific plate bending. A finite element method is developed to simulate this coiling process. Based on numerical simulation, the effects of the coiling parameters on the mechanics and deformation of the bending plate are obtained. Numerical simulation tests have verified the validity of the developed model.     

Comments on enhanced yoking proof protocols for radio frequency identification tags and tag groups

A radio frequency identification (RFID) yoking proof scheme can generate proofs of simultaneous presence of two tags in the range of a specified reader so that an off-line verifier can verify the proofs later. This proof has found several interesting applications. However, many existing RFID yoking schemes are vulnerable to replay attacks. To overcome the weaknesses, Cho et al. proposed a new RFID yoking proof protocol and a new grouping protocol. Unfortunately, Cho et al.’s schemes are still vulnerable to replay attacks. In this paper, in addition to demonstrating weaknesses, we further discuss the rationale behind these weaknesses to provide a guide line for designing secure RFID yoking schemes. Based on the guide line, we propose a new RFID yoking scheme and a new RFID grouping scheme. Performance evaluation shows that our scheme outperforms its counterparts.     

Application of the reverse 3D scanning method to evaluate the wear of forging tools divided on two selected areas

This study is focused on tools used in the industrial hot forging process of a front wheel forging (eventually–gear wheel) manufactured for the automotive industry. Four different variants were applied for the tools: 2 die inserts were coated with two different hybrid layers (GN + PVD type), i.e. AlCrTiN and AlCrTiSiN, one insert was only nitrided, and one was pad welded, to improve tool durability. The tool wear was analysed and represented by the material degradation on the working surface, based on the 3D scanning and the material growth of the periodically collected forgings. Additionally, the scanned tools were divided into two areas, in which it was found, based on the reliminary analysis, that various degradation mechanisms are predominant. Microstructural and hardness measurements of the analyzed tools were also performed. Based on the results, it was found that, in the central part of the die insert (area A), thermo-mechanical fatigue and wear occurred, while in the area of the bridge insert (area B), only abrasive wear could be observed. For these areas (A and B), the loss of material was determined separately. In area A for the inserts with hybrid layer GN+AlCrTiSiN and gas nitrided, an intensive increase of wear took place, which was not observed for the pad welded and GN+AlCrTiN layer insert, for which, together with the increase of the forging number, a proportional growth of the loss of material occurred. In area B the weakest results were obtained for the insert with GN+AlCrTiSiN layer, while wear of other die inserts grew similar and proportional.     

Finite element modeling of hydrostatic stress distribution in copper dual-damascene interconnects

Hydrostatic stresses of copper dual-damascene interconnects are calculated by a commercial finite element software in this paper. The analytical work is performed to examine the effects of different low-k (k is permittivity) dielectrics, barrier layer and aspect ratio of via on hydrostatic stress distribution in the copper interconnects. The results of calculation indicate that the hydrostatic stresses are highly non-uniform throughout the copper interconnects and the highest tensile hydrostatic stress exists on the top interface of lower level interconnect near via. Both the high coefficient of thermal expansion and the low elastic modulus of the low-k dielectrics and barrier layer can decrease the highest hydrostatic stress on the top interface, which can improve the reliability of the copper interconnects.     

Lightweight mixture faults detection method for gasoline engine using on-line trend analysis

Mixture faults detection is meaningful for gasoline engines because proper mixture is the basic prerequisite for healthy running of a combustion engine. Among existing methods for faults detection, the data-driven trend analysis technique is widely used due to the simplicity and efficiency in time-domain. The CUSUM (Cumulative Sum Of Errors) algorithm is good at real-time trend extraction, but it’s easy to be costly on the fuel trim signal during the engine in normal working conditions, which will increase battery energy consumption because engine failure is rarely occurs. Hence, the conventional treatment methods of artifacts in the CUSUM algorithm are modified by means of decay function and detection time analysis. The thresholds are tuned according to the characteristics of artifacts instead of residual variability, which leads to better results of trend extraction and less computation. Then, the revised CUSUM algorithm is used for monitoring the mixture abnormal behaviors, and the mixture faults can be detected in real time through analyzing the variation features of fuel trim signal. The lightweight faults detector using the advanced CUSUM algorithm (FD-A-CUSUM) is evaluated on the experimental data collected from a Ford engine. The validation results show that while engine works under normal conditions, the computation of FD-A-CUSUM has decreased by 72.79 % in comparison with the detection method using the original CUSUM algorithm (FD-O-CUSUM), and the false alarm ratio of FD-A-CUSUM is 3.37 %. Futhermore, the detection results of FD-A-CUSUM for two leakage faults have achieved 91.18 % test accuracy.     

Numerical method for simulating tire rolling noise by the concept of periodically exciting contact force

For the numerical simulation of tire rolling noise, an important subject is the extraction of normal velocity data of the tire surface that are essential for the acoustic analysis. In the current study, a concept of periodically exciting contact force is introduced to effectively extract the tire normal velocity data. The ground contact pressure within contact patch that is obtained by the static tire contact analysis is periodically applied to the whole tread surface of stationary tire. The periodically exciting contact forces are sequentially applied with a time delay corresponding to the tire rolling speed. The tire vibration is analyzed by the mode superposition in the frequency domain, and the acoustic analysis is performed by commercial BEM code. The proposed method is illustrated through the numerical experiment of 3-D smooth tire model and verified from the comparison with experiment, and furthermore the acoustical responses are investigated to the tire rolling speed.     

Feasibility study for the application of air inflated membrane structure in China National Stadium

China National Stadium, also known as “Bird’s Nest”, is the main stadium of the 29th Olympic Games in Beijing in 2008, which has successfully held not only the Opening and the Closing ceremonies but also the track and field events. A new problem of rain preventing is brought out to improve the utilization of the Bird’s Nest after the Olympic Games. The scheme of installing an air inflated membrane at the opening of the steel structure is proposed in this paper to solve the rainproof problem of the Bird’s Nest. The form-finding and mechanical analyses of the air inflated membrane are carried out. Comparison between the mechanical performance and dynamical character before and after installing the air inflated membrane structure is given. To verify the analysis results, based on the practical structure of the Bird’s Nest, a test of a 1:20 model membrane is worked out.