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Yoshikazu Yamamoto

Bio: Yoshikazu Yamamoto is an academic researcher from Keio University. The author has contributed to research in topics: Unified Modeling Language & Web server. The author has an hindex of 9, co-authored 21 publications receiving 392 citations.

Papers
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Proceedings Article
14 Jun 1999
TL;DR: An extension to Unified Modeling Language (UML) is proposed to support aspects properly without breaking the existing UML specification, which allows developers to recognize and understand aspects in the design phase explicitly.
Abstract: Aspect-Oriented Programming (AOP) has been considered a promising abstraction principle to reduce the problem of code tangling and make software structure clean and configurable. This paper addresses the aspect support in the design level while it has been focused mainly in the implementation/coding phase. We propose an extension to Unified Modeling Language (UML) to support aspects properly without breaking the existing UML specification. This allows developers to recognize and understand aspects in the design phase explicitly. Also, we propose a XMLbased aspect description language, UXF/a. It provides the interchangeability of aspect model information between development tools such as CASE tools and aspect weavers.

145 citations

Proceedings ArticleDOI
07 Oct 2003
TL;DR: Implementation and evaluation of this ID recognition system showed that a mobile augmented reality system can be achieved by combining thisID recognition system with a PDA and a wireless network.
Abstract: An ID recognition system is described that uses optical beacons and a high-speed image sensor. The ID sensor captures a scene like an ordinary camera and recognizes the ID of a beacon emitted over a long distance. The ID recognition system has three features. The system is robust to changes in the optical environment, e.g. complete darkness, spotlights, and sunlight. It can recognize up to 255 multiple optical beacons simultaneously. Furthermore, it can recognize beacons even over a long distance, e.g. 40 m indoors and 20 m outdoors. Implementation and evaluation of this ID recognition system showed that a mobile augmented reality system can be achieved by combining this ID recognition system with a PDA and a wireless network.

93 citations

Proceedings ArticleDOI
01 Sep 1998
TL;DR: UXF (UML exchange Format) is proposed, which is an exchange format for UML models, based on XML (Extensible Markup Language), which is a format powerful enough to express, publish, access and exchange U ML models and a natural extension from the existing Internet environment.
Abstract: It is hard to manage the software design documents within a distributed development team. The issues include the format, distribution and evolution of data. This paper mainly focuses on the issues of the format and distribution, and addresses how we can manage the software design documents for the distributed software development in the standard based way. In the software engineering community, Unified Modeling Language (UML) has been widely accepted as an object-oriented software analysis/design methodology, since it provides most of the concepts and notations that are essential for documenting object oriented models. UML, however, does not have an explicit format for interchanging its models intentionally. This paper addresses this lack and proposes UXF (UML exchange Format), which is an exchange format for UML models, based on XML (Extensible Markup Language). It is a format powerful enough to express, publish, access and exchange UML models and a natural extension from the existing Internet environment. It serves as a communication vehicle for developers, and as a well-structured data format for development tools. We demonstrate some proof-of-concept applications that show the merits of UXF. We are especially interested in a distributed model management system that manages the software design documents over the Internet with UXF. This system leverages the team development, reuse of design documents and tool interoperability by publishing a set of CORBA interfaces. Our work shows an important step in sharing and exchanging software design documents, and indicates the future direction of the interoperable software development tools.

57 citations

Journal ArticleDOI
TL;DR: The extension of the UML metamodel for specifying reflective software components allows for recognizing and understanding reflective components in the upper levels of abstraction at an earlier stage of the development process.
Abstract: This paper describes our extension of the UML metamodel for specifying reflective software components. Reflection is a design principle that allows a system to have a representation of itself in the manner that makes it easy to adapt the system to a changing environment. It has matured to the point where it is used to address real-world problems in various areas. We describe how to document reflective components in the framework of UML. Our work allows for recognizing and understanding reflective components in the upper levels of abstraction at an earlier stage of the development process. It leverages the documentation, learning, visual modeling, reuse and roundtrip development of metalevel designs. We also demonstrate the seamless model exchange between different development tools and model continuity across development phases with application-neutral interchange formats.

15 citations

Book ChapterDOI
TL;DR: An interchange format called UXF (UML eXchange Format) based on XML (Extensible Markup Language) is developed, which leverages the tool interoperability, team development and reuse of design models by interchanging the model information with the the XML standard.
Abstract: Unified Modeling Language (UML) has been widely accepted in the software engineering area, because it provides most of the concepts and notations that are essential for documenting object-oriented models. However, UML does not have an explicit format to describe and interchange its model information intentionally. This paper addresses the UML model interchange and presents our efforts to make UML highly interoperable. We developed an interchange format called UXF (UML eXchange Format) based on XML (Extensible Markup Language). UXF is a simple and well-structured format to encode UML models. It leverages the tool interoperability, team development and reuse of design models by interchanging the model information with the the XML standard. Also, we propose an open distribution platform for UML models, which provides multiple levels of interoperability of UML models. Our work shows an important step in the evolution for the interoperable UML.

14 citations


Cited by
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Proceedings ArticleDOI
17 Mar 2003
TL;DR: It is argued that such modularisation makes it possible to establish early trade-offs between aspectual requirements hence providing support for negotiation and subsequent decision-making among stakeholders.
Abstract: An effective requirements engineering (RE) approach must harmonise the need to achieve separation of concerns with the need to satisfy broadly scoped requirements and constraints. Techniques such as use cases and viewpoints help achieve separation of stakeholders' concerns but ensuring their consistency with global requirements and constraints is largely unsupported. In this paper we propose an approach to modularise and compose such crosscutting, aspectual requirements. The approach is based on separating the specification of aspectual requirements, non-aspectual requirements and composition rules in modules representing coherent abstractions and following welldefined templates. The composition rules employ informal, and often concern-specific, actions and operators to specify how an aspectual requirement influences or constrains the behaviour of a set of non-aspectual requirements. We argue that such modularisation makes it possible to establish early trade-offs between aspectual requirements hence providing support for negotiation and subsequent decision-making among stakeholders. At the same time early separation of crosscutting requirements facilitates determination of their mapping and influence on artefacts at later development stages. A realisation of the proposed approach, based on viewpoints and the eXtensible Markup Language (XML), supported by a tool called ARCaDe and a case study of a toll collection system is presented.

443 citations

Journal ArticleDOI
TL;DR: In this article, the authors provide a technology overview and a review on optical wireless technologies, such as visible light communication, light fidelity, optical camera communication, free space optical communication, and light detection and ranging.
Abstract: New high-data-rate multimedia services and applications are evolving continuously and exponentially increasing the demand for wireless capacity of fifth-generation (5G) and beyond. The existing radio frequency (RF) communication spectrum is insufficient to meet the demands of future high-data-rate 5G services. Optical wireless communication (OWC), which uses an ultra-wide range of unregulated spectrum, has emerged as a promising solution to overcome the RF spectrum crisis. It has attracted growing research interest worldwide in the last decade for indoor and outdoor applications. OWC offloads huge data traffic applications from RF networks. A 100 Gb/s data rate has already been demonstrated through OWC. It offers services indoors as well as outdoors, and communication distances range from several nm to more than 10 000 km. This paper provides a technology overview and a review on optical wireless technologies, such as visible light communication, light fidelity, optical camera communication, free space optical communication, and light detection and ranging. We survey the key technologies for understanding OWC and present state-of-the-art criteria in aspects, such as classification, spectrum use, architecture, and applications. The key contribution of this paper is to clarify the differences among different promising optical wireless technologies and between these technologies and their corresponding similar existing RF technologies.

338 citations

Journal ArticleDOI
TL;DR: This work designed the smart camera as a fully embedded system, focusing on power consumption, QoS management, and limited resources, and combined several smart cameras to form a distributed embedded surveillance system that supports cooperation and communication among cameras.
Abstract: Recent advances in computing, communication, and sensor technology are pushing the development of many new applications. This trend is especially evident in pervasive computing, sensor networks, and embedded systems. Smart cameras, one example of this innovation, are equipped with a high-performance onboard computing and communication infrastructure, combining video sensing, processing, and communications in a single embedded device. By providing access to many views through cooperation among individual cameras, networks of embedded cameras can potentially support more complex and challenging applications - including smart rooms, surveillance, tracking, and motion analysis - than a single camera. We designed our smart camera as a fully embedded system, focusing on power consumption, QoS management, and limited resources. The camera is a scalable, embedded, high-performance, multiprocessor platform consisting of a network processor and a variable number of digital signal processors (DSPs). Using the implemented software framework, our embedded cameras offer system-level services such as dynamic load distribution and task reconfiguration. In addition, we combined several smart cameras to form a distributed embedded surveillance system that supports cooperation and communication among cameras.

302 citations

Journal ArticleDOI
TL;DR: This article discusses the topic of learning objects in three parts, identifying a need for learning objects and describing their essential components based on this need, and drawing on concepts from recent developments in computer science to describe learning objects from a theoretical perspective.
Abstract: This article discusses the topic of learning objects in three parts. First, it identifies a need for learning objects and describes their essential components based on this need. Second, drawing on concepts from recent developments in computer science, it describes learning objects from a theoretical perspective. Finally, it describes learning objects in practice, first as they are created or generated by content authors, and second, as they are displayed or used by students and other client groups.

296 citations

Proceedings ArticleDOI
01 Jul 2001
TL;DR: This paper demonstrates how composition patterns map to one programming model that provides a solution for separation of cross-cutting requirements in code—aspect-oriented programming, and serves to illustrate that separation of aspects may be maintained throughout the software lifecycle.
Abstract: Requirements such as distribution or tracing have an impact on multiple classes in a system. They are cross-cutting requirements, or aspects. Their support is, by necessity, scattered across those multiple classes. A look at an individual class may also show support for cross-cutting requirements tangled up with the core responsibilities of that class. Scattering and tangling make object-oriented software difficult to understand, extend and reuse. Though design is an important activity within the software lifecycle with well-documented benefits, those benefits are reduced when cross-cutting requirements are present. This paper presents a means to mitigate these problems by separating the design of cross-cutting requirements into composition patterns. Composition patterns require extensions to the UML, and are based on a combination of the subject-oriented model for composing separate, overlapping designs, and UML templates. This paper also demonstrates how composition patterns map to one programming model that provides a solution for separation of cross-cutting requirements in code—aspect-oriented programming. This mapping serves to illustrate that separation of aspects may be maintained throughout the software lifecycle.

255 citations