The firing squad synchronization problem for graphs

In this paper, we give a solution of the Firing Squad Synchronization Problem for graphs. The synchronization times of solutions which have been obtained are proportional to the number of nodes of a graph. The synchronization time of our solution is proportional to the radius r_G of a graph (G (3r_G + 1 or 3r_G time units, where r_G, is the longest distance between the general and any other node of G. This synchronization time is minimum for an infinite number of graphs.     

Development and Comparison of Two Types of Cryogen-Free Dilution Refrigerator

Dilution refrigerators are an important tool used in solid state and quantum fluid physics for cooling to temperatures below 0.3 K. Conventional dilution refrigerators consume a lot of liquid helium, which has to be recharged in a helium bath every few days. Cryogen-free dilution refrigerators, however, do not use liquid helium and then automatic operation by electricity can be possible from room temperature to the mK region. In near future, therefore, most conventional dilution refrigerators will be replaced by cryogen-free refrigerators because they are easy to operate, do not require maintenance and do not consume helium. We have developed two types of cryogen-free dilution refrigerator. One is directly cooled by a pulse tube refrigerator in the same cryostat using copper thin wires as a thermal link, and the other is cooled by a separate Gifford McMahon refrigerator using circulating helium gas through a flexible syphon tube. The latter has been developed as a vibration-free cryogen-free dilution refrigerator. These two types of cryogen-free dilution refrigerator are compared considering several key points: base temperature, precooling time, minimum temperature and vibration amplitude.     

Clamped‐inverter circuit architecture for luminescent‐period‐control driving of active‐matrix OLED displays

Abstract— An innovative pixel‐driving technology for high‐performance active‐matrix OLED flat‐panel displays is described. Called “clamped‐inverter circuit architecture,” it uses luminescent‐period‐control driving to reduce the inter‐pixel non‐uniformity caused by the device‐to‐device variability of low‐temperature poly‐Si TFTs. A prototype full‐color display shows a luminous deviation of less than 1.6%, which corresponds to only the LSB‐error in 6‐bit gray‐scale.