An Air Pressure Control Method for Fast and Precise Inspection on Triple Action Pressure Sensors

In this study, we proposed a multi-section gradient control method for fast and precise inspection on triple action pressure sensors, which is used to check the abnormal low, mid, and high pressures of the compressor. The multi-section gradient control is divided into time sections that change either rapidly or slowly as the pressure rises or falls, respectively. In the low-speed sections, the pressures are slowly changed so as to allow for precise measurements, while in the high-speed sections, the pressures are quickly changed in order to shorten the inspection time. This involves calculating the target (set-point) values of steps in each section in real time and adjusting the present value using the Proportional Integral Derivative (PID) control method. In order to verify the proposed method, we constructed an automatic inspection system and ran experiments to evaluate the performance. These performance results exhibited an error rate of 0.286% while the semi-automatic inspection took an error rate of 0.857%. The inspection time was greatly shortened to the point that the automatic inspection took less than 12 seconds per product while the semi-automatic inspection took about 30 seconds. The experimental results showed high reliability and shortened inspection time.

     

Change impact analysis for requirements: A metamodeling approach

ContextFollowing the evolution of the business needs, the requirements of software systems change continuously and new requirements emerge frequently. Requirements documents are often textual artifacts with structure not explicitly given. When a change in a requirements document is introduced, the requirements engineer may have to manually analyze all the requirements for a single change. This may result in neglecting the actual impact of a change. Consequently, the cost of implementing a change may become several times higher than expected.ObjectiveIn this paper, we aim at improving change impact analysis in requirements by using formal semantics of requirements relations and requirements change types.MethodIn our previous work we present a requirements metamodel with commonly used requirements relation types and their semantics formalized in first-order logic. In this paper the classification of requirements changes based on structure of a textual requirement is provided with formal semantics. The formalization of requirements relations and changes is used for propagating proposed changes and consistency checking of proposed changes in requirements models. The tool support for change impact analysis in requirements models is an extension of our Tool for Requirements Inferencing and Consistency Checking (TRIC).ResultsThe described approach for change impact analysis helps in the elimination of some false positive impacts in change propagation, and enables consistency checking of changes.ConclusionWe illustrate our approach in an example which shows that the formal semantics of requirements relations and change classification enables change alternatives to be proposed semi-automatically, the reduction of some false positive impacts and contradicting changes in requirements to be determined.     

Measurement and compensation of errors in absolute encoder using dual absolute encoder system

The dual absolute encoder (DAE) system is a measurement system for a motion control system that comprises two absolute encoders and one reduction mechanism. In terms of accuracy and measuring range, DAE is superior to ordinary dual encoder systems, which comprise one incremental encoder, one absolute encoder, and a reduction mechanism. In this study, we focus on the error measurement and compensation using DAE system. There have been many studies to measure and compensate for the errors in measuring systems. However, this typically demands high precision equipment to measure the errors, and attaching and detaching the equipment affects the errors. We measured the errors in the absolute encoder by using the DAE systems solely. The measured errors are modeled using harmonic functions and compensated for by using the modeled errors. The experimental results reveal that the maximum errors and mean absolute errors decrease by one-seventh and one-twelfth, respectively, after error compensation. As a result, we can compensate the errors in the encoders with the encoder system, itself. Additionally, the modeled errors in a DAE system are observed to remain constant even when changing the reduction ratios between two absolute encoders. Once the errors are measured and modeled in the DAE system, the modeled errors can be applied to a DAE system with a different reduction ratio for error compensation.

     

Smart card-based secure authentication protocol in multi-server IoT environment

Multimedia Tools and Applications - In recent years, the internet of things has been widely utilized in various fields, such as in smart factories or connected cars. As its domain of application...     

Design of phononic crystals for self-collimation of elastic waves using topology optimization method

Self-collimating phononic crystals (PCs) are periodic structures that enable self-collimation of waves. While various design parameters such as material property, period, lattice symmetry, and material distribution in a unit cell affect wave scattering inside a PC, this work aims to find an optimal material distribution in a unit cell that exhibits the desired self-collimation properties. While earlier studies were mainly focused on the arrangement of self-collimating PCs or shape changes of inclusions in a unit cell having a specific topological layout, we present a topology optimization formulation to find a desired material distribution. Specifically, a finite element based formulation is set up to find the matrix and inclusion material distribution that can make elastic shear-horizontal bulk waves propagate along a desired target direction. The proposed topology optimization formulation newly employs the geometric properties of equi-frequency contours (EFCs) in the wave vector space as essential elements in forming objective and constraint functions. The sensitivities of these functions with respect to design variables are explicitly derived to utilize a gradient-based optimizer. To show the effectiveness of the formulation, several case studies are considered.     

Geometrically invariant watermarking: synchronization through circular Hough transform

This paper addresses a geometrically invariant watermarking method for digital images. Most previous watermarking algorithms perform weakly against geometric distortions, which desynchronize the location for the inserted watermark. Watermark synchronization, which is a process for finding the location for watermark insertion and detection, is crucial for robust watermarking. In this paper, we propose a watermarking method that is robust to geometric distortions. In order to synchronize the location for watermark insertion and detection, we use circular Hough transform, which extracts circular features that are invariant to geometric distortions. The circular features are then watermarked using additive way on the spatial domain. Our method belongs to the category of blind watermarking techniques, because we do not need the original image during detection. Experimental results support the contention that our method is useful and considerably robust against both geometric distortion attacks and signal processing attacks as listed in Stirmark 3.1.

Join processing with threshold-based filtering in MapReduce

Data analytics, in particular those involving heterogeneous data, often require join operations on datasets collected from different sources. MapReduce, one of the most popular frameworks for large-scale data processing, is not suited for joining multiple datasets. This is because MapReduce often produces a large number of redundant intermediate results, irrespective of the size of the joined records. Although several existing approaches attempt to reduce the number of such redundant results using Bloom filters, they may be inefficient if large portions of records are joined or the number of distinct keys is large. To alleviate this problem, we propose a join processing method with threshold-based filtering in MapReduce, called TMFR-Join, which is an abbreviation for “Threshold-based Map-Filter-Reduce Join”. TMFR-Join applies filters according to their performance, which is estimated in terms of false-positive rates. It also provides a general framework for exploiting various filtering techniques that support certain desired operations. The experimental results indicate that the performance of TMFR-Join is close to that of the better of existing join processing techniques, both with and without filters.     

A study on malicious codes pattern advanced analysis using visualization

The expansion of internet technology has made convenience. On the one hand various malicious code is produced. The number of malicious codes occurrence has dramatically increasing, and new or variant malicious code circulation very serious, So it is time to require analysis about malicious code. The being so malicious code pattern extract for malicious code properties of anti-virus company. Visualization possible to make one image for thousands upon thousands of malicious code. and It is possible to extract unseen pattern. Therefore this paper of object is various malicious code analysis besides new or variant malicious code type or form deduction using visualization of strong. Thus this paper proposes unseen malicious code pattern extract.     

Mask-substrate gap control system for exposure equipment

Microsystem Technologies - Precise printed circuit boards (PCBs) and touch screen panels (TSPs) are produced by the proximity exposure patterning process. In the exposure patterning process, the...