Implementation Strategy for the Numerical Efficiency Improvement of the Multiscale Interpolation Wavelet-Galerkin Method

The multiscale wavelet-Galerkin method implemented in an adaptive manner has an advantage of obtaining accurate solutions with a substantially reduced number of interpolation points. The method is becoming popular, but its numerical efficiency still needs improvement. The objectives of this investigation are to present a new numerical scheme to improve the performance of the multiscale adaptive wavelet-Galerkin method and to give detailed implementation procedure. Specifically, the subdomain technique suitable for multiscale methods is developed and implemented. When the standard wavelet-Galerkin method is implemented without domain subdivision, the interaction between very long scale wavelets and very short scale wavelets leads to a poorly-sparse system matrix, which considerably worsens numerical efficiency for large-sized problems. The performance of the developed strategy is checked in terms of numerical costs such as the CPU time and memory size. Since the detailed implementation procedure including preprocessing and stiffness matrix construction is given, researchers having experiences in standard finite element implementation may be able to extend the multiscale method further or utilize some features of the multiscale method in their own applications.     

Secure and reliable electronic record management system using digital forensic technologies

Currently, most records are produced and stored digitally using various types of media storage and computer systems. Unlike physical records such as paper-based records, identifying, collecting, and analyzing digital records require technical knowledge and tools that are not found in archival institutions. As a result, archival institutions face challenges in their attempt to collect digital archives. One approach to overcome this problem is for archival institutions to use digital forensic knowledge and technologies. In this paper, we propose the Digital Archive Management System that integrates digital forensic technologies and archival information management systems to acquire, identify, analyze, and manage digital records in archival intuitions.     

Information delivery scheme of micro UAVs having limited communication range during tracking the moving target

In the proposed scheme, micro Unmanned Aerial Vehicle (micro UAV) is used to find the target and the UAV group is controlled to constantly provide location information to the base while the target is moving. UAVs have a limited communication range and information transmission is only possible through communication among the UAVs. After locating the target within the search area, the UAVs move toward the base station in order to transmit the information to the base station using multihop connectivity. In the proposed scheme, when communication is not possible among the UAVs because the target moves too far away from the base station, UAVs retain the information of the target and move toward the base station, deliver the information to another UAV, return to the target, and repeat the process. The base station calculates the range of target’s location upon receiving the information, and determines whether target tracking is possible with the current number of UAVs. The performance of the proposed scheme was evaluated by a simulation using NS-2.     

Dynamic learning model update of hybrid-classifiers for intrusion detection

Machine Learning as network attack detection is one of the popular methods researched. Signature based network attack detection is no longer convinced the efficiency in the diversified intrusions (Limmer and Dressler in 17th ACM Conference on Computer and Communication Security, 2010). Moreover, as the various Zero-day attacks, non notified attacks cannot be detected (Wu and Banzhaf in Appl Soft Comput 10(1):1–35, 2010). This paper suggests an effective update method of data set on Machine Learning to detect non notified attacks. In addition, this paper compares and verifies the effects of Machine Learning Detection with updated data set to the former methods.     

A study on the thermomechanical behavior of semiconductor chips on thin silicon substrate

This study is concerned with the deformation or warping behavior of thin layered semiconductor structure comprising a silicon substrate, a pattern layer and a polyimide coating layer with its thickness varying from 100um to 50 um. In contrast with the conventional thick semiconductor structure, today’s semiconductor structure is increasingly thin and therefore the warping is extremely conspicuous, being among the major concerns in the structural design of a chip. In the view of thermomechanical analysis of an extremely thin layer structure considered in the present paper, a few parameters on the deformation should be taken into consideration such as the pattern layer and intrinsic stress. To account for the effect of the pattern layer, we make a well educated guess for the mechanical properties, employing the test results and the CBA (Composite Beam Analysis) theory. In addition, we take into consideration the effect of the intrinsic stress due to moisture absorption on deformation. We show that the chip warpage is accurately predicted when all these are properly considered. Furthermore, we have found that the local instability or wrinkling, associated with the nonuniformity or the inhomogeneity in material properties and bonding quality between any two neighboring layers, appears as one important mode of energy relaxation in addition to the overall warpage when the chip thickness becomes very small.     

Visualization for internet of things: power system and financial network cases

Multimedia Tools and Applications - National critical infrastructure networks, such as banks and industrial control systems (ICSs), can be serious damaged in the event of a security incident....     

FATIGUE CRACK GROWTH AND CLOSURE BEHAVIOUR THROUGH A COMPRESSIVE RESIDUAL STRESS FIELD

Behaviour of fatigue crack growth and closure through a compressive residual stress field is investigated by performing fatigue crack growth tests on welded SEN specimens of a structural steel (JIS SM50A). Depending on the type of the initial residual stress in the region of crack growth, the growth and closure of the crack show different behaviour. In particular, in the transition region from a compressive residual stress field to a tensile residual stress field, the fatigue crack growth rates cannot be described by the effective stress intensity factor range ΔK_eff, based on the measured crack opening stress intensity factor K_op. Also it is found that the R'-method using the data of da/dN vs ΔK for residual stress-free specimens, with the effective stress ratio R'[=(K_max+K_r)/(K_min+K_r)], gives non-conservative predictions of the growth rates in the transition region. Observations of crack closure behaviour in this study indicates that partial opening of the crack occurs and this plays an important role in crack growth through a compressive residual stress field. Based on the concept of a partial opening point (defined and measured in this work), fatigue crack growth behaviour can be better explained.