With the aim to improve the effectiveness of SAWSDL service discovery, this paper proposes a novel discovery method for SAWSDL services, which is based on the matchmaking of so-called fine-grained data semantics that is defined via sets of atomic elements with built-in data types. The fine-grained data semantics can be obtained by a transformation algorithm that decomposes parameters at message level into a set of atomic elements, considering the characteristics of SAWSDL service structure and semantic annotations. Then, a matchmaking algorithm is proposed for the matching of fine-grained data semantics, which avoids the complex and expensive structural matching at the message level. The fine-grained data semantics is transparent to the specific data structure of message-level parameters, therefore, it can help to match successfully similar Web services with different data structures of parameters. Moreover, a comprehensive measure is proposed by considering together several important components of SAWSDL service descriptions at the same time. Finally, this method is evaluated on SAWSDL service discovery test collection SAWSDL-TC2 and compared with other SAWSDL matchmakers. The experimental results show that our method can improve the effectiveness of SAWSDL service discovery with low average query response time. The results imply that fine-grained parameters fit to represent the data semantics of SAWSDL services, especially when data structures of parameters are not important for semantics.

We focus on non-conflicting construction of an optical multistage feedforward network to emulate the N-to-1 output buffer multiplexer by using switched fiber delay line (SDL). In [1], Y.T. Chen et al. presented a sufficient condition (an upper bound) for the number of delay lines required for such a multiplexer with variable length bursts. In this paper, we first give an improved upper bound. Then we develop a framework to construct an arrival case of bursts which can be used to achieve a necessary condition (a lower bound). These results are further extended to the feedforward construction of N-to-N output buffer switch. Through simulation and performance comparison, we find that the new bounds can significantly decrease the hardware cost for constructing both the feedforward SDL-based multiplexer and output buffer switch while still provide the same performance as that of the old ones.

Differential power analysis (DPA) is an effective technique that extracts secret keys from cryptographic systems through statistical analysis of the power traces obtained during encryption and decryption operations. This letter proposes symmetric discharge logic (SDL), a circuit-level countermeasure against DPA, which exhibits uniform power traces for every clock period by maintaining a set of discharge paths independent of input values. This feature minimizes differences in power traces and improves resistance to DPA attacks. HSPICE simulations for the test circuits using 0.18 µm TSMC CMOS process parameters indicate that SDL reduces power differences by an order of magnitude, compared to the existing circuit-level technique.

It has become more important to reduce the protocol implementation costs as the functions of protocols have become more abundant. The protocol implementation tools which automatically generate a protocol program from a specification described by an FDT (Formal Description Technique) are very promising. Selecting SDL as a target FDT, we have developed an SDL-based protocol implementation tool which consists of a process scheduler and a compiler. Since the efficient SDL process execution is a key to generating the high-speed program, the scheduler is introduced. It provides the mechanism which executes SDL processes concurrently as light-weight-processes. It optimizes so that as few context switches take places as possible. The compiler converts as many kinds of SDL functions whose behaviors can be determined at compile time into programming language statements as possible. These elaborations are so successful that the tool can generate an efficient program. The OSI Transport protocol class 0 program generated by the compiler can process more than 500 packets per second on a 6MIPS workstation.

The purpose of this paper is to propose a technique to simplify the communications software descriptions written in a procedural language in order to enhance their comprehensibility. Although such a technique was not much studied and discussed in the past, this technique is important to realize high productivity and high quality of the communications software by reducing the complexity of the software description. This paper firstly systematically presents various simplification methods with their principles for the descriptions of the communications software from the viewpoints of their layout, syntactical structures etc. Then, it describes a simplification support system based on these principles for the software specifications written in SDL. Lastly, this paper demonstrates the usefulness and effectiveness of the proposed simplification technique by analyzing the evaluation results of the simplification system.