BiCMOS circuit technology for a 704 MHz ATM switch LSI

This paper describes BiCMOS level-converter circuits and clock circuits that increase VLSI interface speed to 1 GHz, and their application to a 704 MHz ATM switch LSI. An LSI with a high speed interface requires a BiCMOS multiplexer/demultiplexer (MUX/DEMUX) on the chip to reduce internal operation speed. A MUX/DEMUX with minimum power dissipation and a minimum pattern area can be designed using the proposed converter circuits. The converter circuits, using weakly cross-coupled CMOS inverters and a voltage regulator circuit, can convert signal levels between LCML and positive CMOS at a speed of 500 MHz. Data synchronization in the high speed region is ensured by a new BiCMOS clock circuit consisting of a pure ECL path and retiming circuits. The clock circuit reduces the chip latency fluctuation of the clock signal and absorbs the delay difference between the ECL clock and data through the CMOS circuits. A rerouting-Banyan (RRB) ATM switch, employing both the proposed converter circuits and the clock circuits, has been fabricated with 0.5 μm BiCMOS technology. The LSI, composed of CMOS 15 K gate logic, 8 Kb RAM, I Kb FIFO and ECL 1.6 K gate logic, achieved an operation speed of 704-MHz with power dissipation of 7.2 W     

Inductive Synthesis of Recursive Processes from Logical Properties

This paper proposes an inductive synthesis algorithm for a recursive process. To synthesize a process, facts, which must be satisfied by the target process, are given to the algorithm one by one since such facts are infinitely many in general. When n facts are input to the algorithm, it outputs a process which satisfies the given n facts. And this generating process is repeated infinitely many times. To represent facts of a process, we adopt a subcalculus of μ-calculus. First, we introduce a new preorder _d on recursive processes based on the subcalculus to discuss its properties. p_d q means that pf implies qf, for all formulae f in the subcalculus. Then, its discriminative power and relationship with other preorders are also discussed. Finally, we present the synthesis algorithm. The correctness of the algorithm can be stated that the output sequence of processes by the algorithm converges to a process, which cannot be distinguished from the intended one (if we could know it) by a given enumeration of facts, in the limit. A prototype system based on the algorithm is stated as well.     

Very-high-speed Si bipolar static frequency dividers with newT-type flip-flops

This paper presents two circuit techniques for highspeed operation of a master-slave toggle flip-flop circuit (MSTFF). One circuit reduces the gain in latching circuits, and the other uses the transient current of the emitter followers to boost the switching speed. Both the SPICE simulations and the measured results for static 1/8 frequency dividers fabricated using 0.5-μm super self-aligned process technology (SSTIC) show that the maximum operating speed of our MS-TFF's is 10% and 30% faster than that of conventional ones. By applying these technologies, 19.1-GHz and 22.4-GHz Si bipolar static frequency dividers have been fabricated     

Fabrication of Langmuir-Blodgett films using amphiphilic peptides

To introduce self-organization ability of transmembrane proteins into Langmuir (L) and Langmuir-Blodgett (LB) techniques, we focused on "amphiphilic peptide" (AP) which is composed of two distinct hydrophilic and hydrophobic domains. Three types of APs of different average hydropathies were used to prepare the AP/lipid mixed L and LB films. According to the circular dichroism spectra, the secondary structures of APs were not uniform but were a mixture of alpha-helix, beta-strand and random coil. The fraction of alpha-helix was higher for lower hydropathy AP. The interaction between AP and lipid in the L film and the structure of the LB film were also depended on the APs used.     

A-SATCHMORE: SATCHMORE with availability checking

We present an improvement of SATCHMORE, calledA-SATCHMORE, by incorporating availability checking into relevancy. Because some atoms unavailable to the further computation are also marked relevant, SATCHMORE suffers from a potential explosion of the search space. Addressing this weakness of SATCHMORE, we show that an atom does not need to be marked relevant unless it is available to the further computation and no non-Horn clause needs to be selected unless all its consequent atoms are marked availably relevant, i.e., unless it is totally availably relevant. In this way,A-SATCHMORE is able to further restrict the ues of non-Horn clauses (therefore to reduce the search space) and makes the proof more goal-oriented. Our theorem prover,A-SATCHMORE, can be simply implemented in PROLOG based on SATCHMORE. We discuss how to incorporate availability cheeking into relevancy, describe our improvement and present the implementation. We also prove that our theorem prover is sound and complete, and provide examples to show the power of our availability approach. This research is supported in part by the Japanese Ministry of Education and the Artificial Intelligence Research Promotion Foundation. Lifeng He, Ph.D: He received the B. E. degree from Northwest Institute of Light Industry, China, in 1982, the M. S. and Ph.D. degrees in AI and computer science from Nagoya Institute of Technology, Japan, in 1994 and 1997, respectively. He currently works at the Institute of Open System in Nagoya, Japan. His research interests include automated reasoning, theorem proving, logic programming, knowledge bases, multi-agent cooperation and modal logic. Yuyan Chao, M. S.: She received the B. E. degree from Northwest Institute of Light Industry, China, in 1984, and the M. S. degree from Nagoya University, Japan, in 1997. She is currently a doctoral candidate in the Department of Human Information, Nagoya University. Her research interests include image processing, graphic understanding, CAD and theorem proving. Yuka Shimajiri, M. S.: She currently works as a Assistant Professor in Department of Artificial Intelligence and Computer Science at the Nagoya Institute of Technology. She received her B.Eng. and M.Eng. from the Nagoya Institute of Technology in 1994 and 1996, respectively. Her current research interests include logic programming and automated deduction. She is a member of IPSJ and JSAI. Hirohisa Seki, Ph.D.: He received the B. E., M. E. and Ph.D degrees from the University of Tokyo in 1979, 1981 and 1991 respectively. He joined the Central Research Laboratory of Mitsubishi Electric Corporation in 1981. From 1985 to 1989, he was with the Institute for New Generation Computer Technology (ICOT). Since 1992, he has been an Associate Professor in the Department of AI and Computer Science at Nagoya Institute of Technology. His current research interests include logic programming, deductive databases and automated deduction. He is a member of ACM, IEEE, IPSJ and JSAI. Hidenori Itoh, Ph.D.: He received the B. S. degree from Fukui University, in 1969, the M. S. degree and Ph.D degree from Nagoya University, Japan, in 1971 and 1974, respectively. From 1974 to 1985, he worked at Nippon Telephone and Telegraph Laboratories, developing operating systems. From 1985 to 1989, he was with the Institute for New Generation Computer Technology, developing knowledge base systems. Since 1989, he has become a professor at the Nagoya Institute of Technology. His current research interests include image processing, parallel computing, fuzzy logic and knowledge processing.     

Characterization of micro-flocs of NOM coagulated by PACl, alum and polysilicate-iron in terms of molecular weight and floc size.

Micro-flocs of NOM coagulated by polyaluminium chloride (PACl), alum and polysilicate-iron (PSI) were characterized by flocs size, HPSEC-based molecular weight and the captured content of coagulants-based aluminium and iron. Changes in floc composition with respect to the mass ratios of captured NOM to Al and Fe were examined. Lowering water pH to optimum levels was found to be capable of removing small NOM constituents that are generally difficult to be precipitated at neutral pH levels. For PACl and PSI, the distribution of micro flocs (0.1-5.0 microm) reached steady stage after rapid mixing for 30 seconds, with NOM being found existent within the non-coagulated fraction (d<0.1 microm) and the coagulated fraction with floc sizes above 5.0 microm (d >5.0 microm). For alum, however, the existence of NOM inside intermediate floc fractions of d = 0.1-1.0 microm, 1.0-3.0microm and 3.0-5.0 microm was confirmed.