Kimio Kuramitsu

Towards ubiquitous database in mobile commerce

Ubiquitous database places data everywhere. We focus on contactless smartcards combined with a small processor and memory for data storage. Very small DBMS implemented on them can interact through queries on a wireless communication. Ubiquitous database attaches such DBMSs to real world “objects” physically, and then allows different organizations to share information retrieved directly from physical goods, materials, or persons. We combined the theory with practice in the ticket digitalization project. Through the experience of our project, this paper will discuss how to manage ubiquitous database in the context of mobile commerce applications.

TTP: secure ACID transfer protocol for electronic ticket between personal tamper-proof devices

The expanding market for digital content increases the demand to transfer electronic value through open networks. This paper describes the Ticket Transfer Protocol (TTP), which enables electronically transferable tickets to directly move between two personal tamper-proof devices. The applied two-phase commit protocol for the transfer realizes the ACID (atomicity, consistency, isolation, durability) transaction properties without any external coordinators. Moreover, this paper addresses the initial implementation of a secure TTP, enabling the detection of message replays by attackers, and evaluates the size of its logging field in the transaction. We conclude that TTP has enough reliability to transfer electronic tickets directly between personal ticket wallets.

Packrat parsing with elastic sliding window

Packrat parsing is a linear-time implementation method of recursive descent parsers. The trick is a memoization mechanism, where all parsing results are memorized to avoid redundant parsing in cases of backtracking. An arising problem is extremely huge heap consumption in memoization, resulting in the fact that the cost of memoization is likely to outweigh its benefits. In many cases, developers need to make a difficult choice to abandon packrat parsing despite the possible exponential time parsing. Elastic packrat parsing is developed in order to avoid such a difficult choice. The heap consumption is upper-bounded since memorized results are stored on a sliding window buffer. In addition, the buffer capacity is adjusted by tracing each of nonterminal backtracking activities at runtime. Elastic packrat parsing is implemented in a part of our Nez parser. We demonstrate that the elastic packrat parsing achieves stable and robust performance against a variety of inputs with different backtracking activities.

Digiket: decentralized architecture for worldwide electronic market

Proposes a new decentralized architecture for electronic markets, called Digiket (DIGItal marKET), as an alternative to traditional virtual malls. The present Internet commerce consists of relatively small closed markets; so, new frameworks that enable Web-based stores and malls to share their services worldwide are strongly desired. Digiket separates electronic commerce functions (such as content authoring, catalog delivery, intermediary services, shopping assistants and transaction processing) from traditional mall sites, and decentralizes each of them independently. Digikets architecture is unique in that it requires no central coordinators for the distributed components. Instead, the PCO (Portable Compound Object) language, a lingua franca for Digiket, connects the components to each other. We have also implemented the PCO language and a user agent client named OpenBasket, to demonstrate a shopping application on Digiket. The demonstration shows that a consumer can order arbitrary goods described in PCO without vendor barriers.

Finding periodic outliers over a monogenetic event stream

Sensors are active everywhere. Enormous volumes of sensed events are sent over the data streams, while most of applications want to focus on events that would be curious. We propose a technique for mining periodicities and predicting its outliers from the stream. The key to our technique is a simple periodic pattern /spl Delta/t, derived from delta-time mining, or SUP(t, t+/spl Delta/t). We provide efficient algorithms for finding the highest support /spl Delta/t on a small and resource-limited sensor device. Our experiments compare memory efficiency and accuracy, on a variety of event patterns, monogenesis, polygenesis, and semi-random.

KonohaScript: static scripting for practical use

This demonstration presents the language design of Konoha-Script, a statically typed object-oriented scripting language. KonohaScript provides the very similar scripting experiences compared to dynamic languages. In addition, it also preserves useful programming supports by static typing, such as automated verification of careless mistakes, improved readability of source code, better opportunity of optimized code generation. This demonstration will show how KonohaScript improved scripting experiences with static typing, using our open source implementation fully written in C.

Nez: practical open grammar language

Nez is a PEG(Parsing Expressing Grammar)-based open grammar language that allows us to describe complex syntax constructs without action code. Since open grammars are declarative and free from a host programming language of parsers, software engineering tools and other parser applications can reuse once-defined grammars across programming languages. A key challenge to achieve practical open grammars is the expressiveness of syntax constructs and the resulting parser performance, as the traditional action code approach has provided very pragmatic solutions to these two issues. In Nez, we extend the symbol-based state management to recognize context-sensitive language syntax, which often appears in major programming languages. In addition, the Abstract Syntax Tree constructor allows us to make flexible tree structures, including the left-associative pair of trees. Due to these extensions, we have demonstrated that Nez can parse many grammars of practical programming languages. Nez can generate various types of parsers since all Nez operations are independent of a specific parser language. To highlight this feature, we have implemented Nez with dynamic parsing, which allows users to integrate a Nez parser as a parser library that loads a grammar at runtime. To achieve its practical performance, Nez operators are assembled into low-level virtual machine instructions, including automated state modifications when backtracking, transactional controls of AST construction, and efficient memoization in packrat parsing. We demonstrate that Nez dynamic parsers achieve very competitive performance compared to existing efficient parser generators.

Extensible online log analysis system

These days, embedded systems such as robotics and car navigation systems are composed of a variety of software components. These systems frequently suffer environmental damage and require changes. Improving the adaptation cycles in the development phase is a big challenge in this area. We will provide an extensible online log analysis system that will reduce the debugging cost of the real-time system in the development phase. A real-time system is used as the base of the system. To achieve this, we offer two proposals: One is the online log analysis architecture that will not disturb the target observed system. The second is an extensible analysis framework for detecting errors and faults in the target real-time system. Our system provides methods for treating both input log streams and output results. Results will be shown in the Web browser viewer for root cause analysis by engineers. This system will help the incremental development of complex systems such as robotics that require adaptable improvements in either the developmental or operational phases. In this paper, we will show the prototype architecture and examine its results.

A Declarative Extension of Parsing Expression Grammars for Recognizing Most Programming Languages

Parsing Expression Grammars are a popular foundation for describing syntax. Unfortunately, several syntax of programming languages are still hard to recognize with pure PEGs. Notorious cases appears: typedef-defined names in C/C++, indentation-based code layout in Python, and HERE document in many scripting languages. To recognize such PEG-hard syntax, we have addressed a declarative extension to PEGs. The ”declarative” extension means no programmed semantic actions, which are traditionally used to realize the extended parsing behavior. Nez is our extended PEG language, including symbol tables and conditional parsing. This paper demonstrates that the use of Nez Extensions can realize many practical programming languages, such as C, C#, Ruby, and Python, which involve PEG-hard syntax.

Online Anomaly Symptom Detection and Process's Resource Usage Control

In this paper we propose an online lightweight anomaly symptom detection and process’s resource usage control mechanism. Our system collects fine-grain resource information that can reflect the subtle changes of the application’sbehavior. Then it creates models with a learning-based algorithm without manual configurations. If an anomaly symptom is detected, the automatic procedure will start. The system will control the suspected application’s resource use by limiting the upper bound resource of the process. The method will make the application yield its CPU to the administrative inspection. In this paper, we described whole architecture of the system and evaluate it with the non deterministic and deterministic failure. Our experimental results indicate that our prototype system is able to detect non deterministic failure with high precision in anomaly training and control it’s resource use with an overhead of about 1%.