K.: Model-based Control for Reconfigurable Manufacturing Systems

Abstract: The manufacturing industry cannot stay competitive and survive in today’s market without agile adaptation to rapidly changing customers ’ demands. This in turn requires manufacturing systems to be reconfigurable for timely introduction of new products in the market. Unfortunately, at present, the system designers cannot systematically and completely manage their design data, because the manufacturing systems have gradually become too large and too complicated to manage. In order to reconfigure and reuse H/W and S/W components in manufacturing systems, and improve the engineering environment of system control design, we propose a model-based control design based on state transition diagrams and a general graph description, while taking reconfiguration and reuse of design data into account. We demonstrate the utility of the proposed approach using a real application. 1

Quality improvement of dual-energy lung perfusion image by reduction of low-energy x-ray spectrum : an evaluation on clinical images

BACKGROUND: The effects of the reduction of low-energy X-ray spectrum on lung perfusion images created by dual-energy CT have not been well evaluated. The aim of this study is to investigate the reliability of lung perfusion blood volume (PBV) images created by dual-energy CT (DECT) equipped with or without a tin filter, focusing on its accuracy adjacent to high-attenuation areas. MATERIAL AND METHODS: Among 176 patients who underwent DECT for suspicion of pulmonary embolism, 38 patients (mean age, 64; range, 16 to 83 years) without apparent evidence of pulmonary embolism were evaluated in this study. They underwent DECT at 100/140 kVp with a tin filter on 140 kVp tube (Group A; n=18) or at 80/140 kVp without the filter (Group B; n=20). On the lung PBV images, the degrees of artifacts - pulmonary enhancement defect (PED) and pseudo-enhancement in the trachea (PTE) adjacent to the vena cava were evaluated using a four-point scale (0=minimal to 3=prominent). RESULTS: The mean degrees of artifact in Group A were significantly lower than those in Group B (0.8 vs. 1.9; P<0.0001 for PED, respectively, and 1.1 vs. 2.2; P<0.0001 for TPE, respectively). The mean CTDIvols were 4.90±1.14 and 12.98±3.15 mGy (P<0.0001) for Group A and Group B, respectively. CONCLUSIONS: The quality and accuracy of dual-energy lung perfusion image will be improved by using the tin filter technique