Dai Araki

Specify-explore-refine (SER): from specification to implementation

Driven by increasing complexity and reliability demands, the Japanese Aerospace Exploration Agency (JAXA) in 2004 commissioned development of ELEGANT, a complete SpecC-based environment for electronic system-level (ESL) design of space and satellite electronics. As integral part of ELEGANT, the Center for Embedded Computer System (CECS) has developed and supplied the SER tool set. Following a Specify-Explore-Refine methodology, SER supports system-level design space exploration, interactive platform development and automatic model refinement and model generation. The SER engine has been successfully integrated into ELEGANT. With SER at its core, ELEGANT provides a seamless tool chain for modeling verification and synthesis from top-level specification down to embedded HW/SW implementation. ELEGANT and SER have been successfully delivered to JAXA and its suppliers. Tools are currently being deployed in companies like NEC Toshiba Space Systems. Evaluation results prove the feasibility of the approach for design space exploration, rapid virtual prototyping and system synthesis resulting in tremendous productivity and reliability gains. In addition, ELEGANT has been commercialized for general market availability. The SER component has been licensed to InterDesign Technologies, Inc. (IDT) and it is available from, sold and supported by IDT.

Geographical route planning based on uncertain knowledge

Reports on the development of a geographical route planning system using uncertainty reasoning. This system searches for the route from a start point to a goal point indicated on a map. This system uses the digitized terrain map available from the Japanese Geographical Survey Institute. The target area of the route planning is subdivided into fine meshes of 100 meters square. This system is composed of two reasoning modules: a mobility cost evaluation module and a route planning module. The former module evaluates mobility costs for every 300/spl times/300 meshes included in the designated area. Domain experts often use ambiguous data interpretation knowledge for evaluating terrain circumstances and deciding the mobility cost in a mesh. We introduce two uncertainty reasoning mechanisms to represent such a data interpretation process: one is fuzzy reasoning, and the other is Dempster-Shafer theory. The route planning module uses the F* optimization algorithm. The geographical route planning system also offers knowledge editing facilities for describing the mobility cost evaluation knowledge, such as a dataflow diagram editor for designing the data integration process and a membership function editor for designing data abstraction methods. These knowledge editors facilitate the development and modification of a mobility cost evaluation knowledge base.

Error repair and knowledge acquisition via case-based reasoning

Abstract To cope with the knowledge acquisition bottleneck, the authors propose a new architecture combining rule-based reasoning (RBR), case-based reasoning (CBR) and knowledge acquisition technology in a system which solves pattern search problems. The RBR part searches for specified patterns in a large space represented by a network structure such as an LSI circuit diagram, which contains a great number of patterns and variations. It then carries out specified actions, such as fault diagnosis, on the patterns that are found. The outputs of the RBR part are transferred to the CBR part. The user of the system detects and repairs a few pattern detection errors caused by the RBR part. The CBR part detects and repairs all remaining errors which can be estimated from the user detected ones. The repaired results are sent back to the RBR part to recover the RBR output. The repaired results are also stored automatically in the case base. Similar cases are grouped in a same case family. The knowledge acquisition part relates each case family to an incomplete rule in the RBR knowledge base and proposes modifying the rule. Eventually, the system can obtain refined rules with the cooperation of domain experts. Thus, the problem solving process and knowledge acquisition process are performed cyclically. The architecture was successfully applied to a pair condition extraction problem for an analog LSI circuit layout system.

Development of a distributed cooperative scheduling system based on negotiations between scheduling agents

Using a single concentrated scheduling system in a large-scale manufacturing system is problematic. As a result, scheduling systems are being introduced in departmental units, which has resulted in having to repeat schedule adjustments between departments whenever there is a change in one department. Therefore, the authors propose a horizontal distributed scheduling system to create speed and localization in schedule adjustments which occur frequently between departments by introducing a multiagent model to perform negotiations between schedulers by using each departments scheduler as an agent. The negotiations between schedulers in this system are characterized by defining the negotiation protocol which controls the flow of the negotiations so as to maintain consistency between schedulers and by introducing a mechanism to enable simultaneous execution of multiple negotiations so as to create speed in schedule adjustments. In addition, the authors evaluated the application of this system to scheduling problems in a real multiple work job shop. They confirmed that speed was achieved through simultaneous implementation of multiple negotiations while at the same time consistency in schedules was maintained via negotiations between schedulers.

Rapid prototyping with HW/SW codesign tool

The paper describes a visual design authoring tool named VisualSpec. VisualSpec realizes a homogeneous hardware/software codesign process which means to perform both functional specification design and architectural specification design of HW/SW parts in a single tool and a common design specification language. The design specification captured with VisualSpec is always executable so that the designer can develop a virtual prototype system and simulation model for verifying functional requirements, performance and cost. VisualSpec combines top-down and bottom-up design approaches and facilitates reuse of cores and other IP components.

KASE project toward effective diagnosis system development

Abstract The Knowledge Acquisition Support Environment (KASE) and some case studies on expert system development are described. DiPROS is a diagnostic expert system building tool, which has a knowledge base editor and an inference engine specialized for diagnostic tasks. DiKAST is an interactive knowledge-acquisition (KA) tool, which guides repairs on defects in the knowledge base. In order to build this KA facility, many kinds of KA interview strategies were formalized. We applied KASE tools in building a defect diagnosis system for a color picture tube manufacturing plant. The prototype system was able to be developed in a short time by the domain experts alone, who had no previous experience in computer programming.

Knowledge modeling environment for job-shop scheduling problem

The scheduling model and method must be designed to be application-domain dependent so as to reflect a set of constraints, objectives and preferences which reside in the target problem. We analyzed the scheduling process of human experts in a knowledge-base level and have developed a task-specific shell named ARES/SCH. ARES/SCH possesses a primitive task library that is a collection of domain-independent and generic components of scheduling mechanisms. The whole scheduling method can be described as a combinational flow-chart of primitive tasks. Memory module mounting shop (MMS) scheduling is shown as an example of ARES/SCH applications. It was apparent that ARES/SCH contributes to the rapid development of scheduling systems and supports a wide range of scheduling domains.<<ETX>>