Off-line Checking Research Articles

Detecting measurement issues in SQL arithmetic expressions and aggregations

Research on user errors in retrieving information from SQL databases has focused on erroneous syntax in the query language and erroneous semantics concerning the data model. In the present paper, we investigate a third source of error, namely erroneous aggregations that break the limitations imposed by the numerical properties of the data. An erroneous aggregation might arise because of the SQL programmer’s misunderstanding concerning those numerical properties, or because of a simple mistake. We show that for database queries in the SQL language, significant classes of erroneous aggregations can be detected by non-intrusive, off-line checking, using only a simple set of metadata rules that can be supplied by the data provider. We have implemented software that performs static checks on users’ SQL queries, looking for evidence of misunderstandings concerning the measurement properties of the numerical data.

Design of On-Line Detection System for Paper Defects Based on Line-Scan Camera

Paper defects mean that there are some defects in the paper such as hole, emboss, and fold during the paper production, which mainly results from the limitation of technological level. In the past time, artificial visual inspection and off-line checking were often used to detect the paper defects. However, its shortcoming was highlighted along with the improvement of industrial technology level and increasing demand for paper. In order to realize the online detection and markers for paper defects, the project designs the on-line detection system based on line-scan digital camera. Firstly, the principle and detection scheme of the system for the paper defects was presented. Then the overall structure of the system was designed. After that, the hardware circuit of the system was designed using TMS320F2812 as main control chip. It mainly consists of the function of each module and the working process of the system. Finally, the software of the image acquisition system was presented. With the experimental verification, the system has advantages of low cost, high efficiency and strong resistance to interference. The functions and indexes achieved the design requirements.

Verifying integrity of decision diagrams

Decision diagrams (DDs) are the state-of-the-art data structure in CAD of integrated circuits. They are used in many safety critical applications, like verification. In this paper security aspects of implementation techniques of DDs are discussed. A recursive checksum technique is presented for on- and off-line checks. These methods are used to verify the integrity of DDs. The correctness of the data structures can be verified by (nearly) no overhead. It is demonstrated how the techniques can be combined with operations on DDs, like recursive synthesis and reordering. Experimental results are presented to demonstrate the efficiency of this approach.

Methods of Recording and Analysing Cough Sounds

Efforts have been directed to evolve a computerized system for acquisition and multi-dimensional analysis of the cough sound. The system consists of a PC – AT486 computer with an ADC board having 12 bit resolution. The audio cough sound is acquired using a sensitive miniature microphone at a sampling rate of 8 kHz in the computer and simultaneously recorded in real time using a digital audio tape recorder which also serves as a back up. Analysis of the cough sound is done in time and frequency domains using the digitized data which provide numerical values for key parameters like cough counts, bouts, their intensity and latency. In addition, the duration of each event and cough patterns provide a unique tool which allows objective evaluation of antitussive and expectorant drugs. Both on-line and off-line checks ensure error-free performance over long periods of time. The entire system has been evaluated for sensitivity, accuracy, precision and reliability. Successful use of this system in clinical studies has established what perhaps is the first integrated approach for the objective evaluation of cough.