Yukikazu Nakamoto

Power-Aware Resource Allocation with Fair QoS Guarantee

A power-aware optimal processor cycle allocation scheme with consideration of fair quality of service (QoS) guarantee in real-time systems is formulated. Although power-aware resource management using dynamic voltage and frequency scaling techniques can be used to resolve the trade-off between QoS maximization and energy consumption minimization, it is also necessary to ensure fair QoS allocation in real-time resource allocation to avoid deterioration of QoS levels. The formulation presented in this paper is a multiple-objective optimization problem in which the objective functions are minimization of total enemy consumption and maximization of the QoS level. A Pareto optimal solution representing the trade-off between the two objective functions is obtained numerically using a weighted-sum method for the case that the resource consumption functions are convex. We show an example in cast that all resource consumption functions are linear

Toward Remote Service Invocation in Android

Android has spread as a platform for not only smart phones and tablet devices but also embedded devices. When Android was adapted for embedded systems, various kinds of application software were considered. One of these applications is to build collaborative and cooperative work environments. In developing software for collaborative and cooperative work, transparent invocation of remote services in other devices is expected. In this paper, we evaluate whether the inter-process communication mechanism in Android can be used in remote service invocation using the application layer protocol in the feasibility study. Moreover, we propose intent class extension to realize transparent remote service communication to other devices without any modifications to the Android application.

AEDSMS: Automotive Embedded Data Stream Management System

Data stream management systems (DSMSs) are useful for the management and processing of continuous data at a high input rate with low latency. In the automotive domain, embedded systems use a variety of sensor data and communications from outside the vehicle to promote autonomous and safe driving. Thus, the software developed for these systems must be capable of handling large volumes of data and complex processing. At present, we are developing a platform for the integration and management of data in an automotive embedded system using a DSMS. However, compared with conventional DSMS fields, we have encountered new challenges such as precompiling queries when designing automotive systems (which demands time predictability), distributed stream processing in in-vehicle networks, and real-time scheduling and sensor data fusion by stream processing. Therefore, we developed an automotive embedded DSMS (AEDSMS) to address these challenges. The main contributions of the present study are: (1) a clear understanding of the challenges faced when introducing DSMSs into the automotive field; (2) the development of AEDSMS to tackle these challenges; and (3) an evaluation of AEDSMS during runtime using a driving assistance application.

Real-Time-Aware Embedded DSMS Applicable to Advanced Driver Assistance Systems

Automotive embedded systems are composed of many kinds of sensors, and it is becoming difficult to manage these data. Therefore, we define a vehicle data processing by a Stream Processing Description (SPD), which is the data processing description used in the Data Stream Management Systems (DSMS). However, because existing DSMSs run on generalpurpose systems, it is difficult to deploy DSMSs in automotive embedded systems and fulfill these performance requirements. The DSMS for automotive embedded systems (eDSMS) generates an optimized runtime from the queries defined by an SPD not dynamically (in execution) but statically (in development), which reduces the ROM/RAM usage. In this study, we extend eDSMS for real-time processing and show the extended eDSMS is applicable to the Advanced Driver Assistance Systems (ADAS).

Virtual Software Execution Environments for Distributed Embedded Control Systems

The size and complexity of large-scale distributed embedded systems such as automotive and process controls have increased recently. Sophisticated systems that are safe and environmentally friendly require numerous types of sensor data, which are collected from various devices and sent to computers through networks. To develop such large-scale distributed embedded systems with high dependability and productivity, we have developed a virtual execution environment platform. This platform integrates numerous CPU simulators and various device simulators through the network and provides network-wide simulation functionalities. In this paper, we describe a fast CPU simulator and controlled object simulation for testing control software in a virtual software execution environment. The virtual environment integrates a CPU simulator and a controlled object simulator in order to test functional behaviors of embedded control software. The environment enables the developer to test control software at the same execution rate as a real system without the source codes. This is very helpful because in this industry, not all of the source codes are provided.

Toward Integrated Virtual Execution Platform for Large-Scale Distributed Embedded Systems

The size and complexity of large-scale distributed embedded systems such as automotive and process control have increased recently. Sophisticated systems that are safe and environment friendly in the distributed systems require numerous types of sensor data, which are collected from various devices and sent to computers through networks. In order to develop the large-scale distributed embedded systems with high productivity and quality, a virtual execution environment platform is required. This platform integrates numerous CPU simulators and various device simulators through the network and provides network-wide simulation functionalities in the distributed system. In this paper, we present the requirements and initial system designs of a virtual execution environments platform for the development of the large-scale distributed embedded system software.

An extensible browser architecture for mobile terminals

The number of mobile terminals with a Web browser has increased in recent years, and many diverse mobile services using the Internet have evolved. However, there are still limitations such as that it is difficult to change or replace browser functionalities in mobile terminals. This is a factor in service providers being unable to freely provide services. We propose an extensible browser architecture (EBA) to extend the browser functions. The EBA consists of two layers: browser foundation and browser application layer. The browser foundation layer provides the core functions of the browser as Java class libraries. The browser applications, which are written in the Java language and downloadable, utilize modules using the browser class libraries in the browser foundation layer to provide a variety of browser applications. Several applications demonstrate the effectiveness of the EBA.

The next generation software platform for mobile phones

Recently mobile phones provide not only voice service but internet access, multi-media message services, games, local communication controller and so on. Therefore, more productive software platforms are required. We develop the next generation software platform based on Linux. In the paper, we describe a summary of the software platform. First, back grounds are mentioned, including recent and future functionalities in mobile phones. Then, we summarize requirements for mobile phone Linux. Third, we describe functionalities of middleware for the mobile phones on top of Linux. Lastly future trends in mobile phone software are presented.

A Proposal for Mobile Collaborative Work Support Platform Using an Embedded Data Stream Management System

This paper presents a mobile collaborative work support platform that uses an embedded data stream management system (mDSMS). The collaborative work that we focus on includes activities not only within typical organizations, but also in organizations such as disaster relief centers. These activities are modeled using a meeting-oriented coordination model of distributed systems, because such activities are temporally coupled and referentially uncoupled. We develop a collaborative work support system for Android devices that uses data stream management, which is a key technique of the model. One of the features in mDSMS is a multilayer query scheduling feature that is capable of various holding times for activity messages and assures the timeliness of message processing. We present the architecture and design of mDSMS on the Android platform as well as preliminary evaluation results.

Vehicle Embedded Data Stream Processing Platform for Android Devices

Automotive information services utilizing vehicle data are rapidly expanding. However, there is currently no data centric software architecture that takes into account the scale and complexity of data involving numerous sensors. To address this issue, the authors have developed an in-vehicle data-stream management system for automotive embedded systems (eDSMS) as data centric software architecture. Providing the data stream functionalities to drivers and passengers are highly beneficial. This paper describes a vehicle embedded data stream processing platform for Android devices. The platform enables flexible query processing with a dataflow query language and extensible operator functions in the query language on the platform. The platform employs architecture independent of data stream schema in in-vehicle eDSMS to facilitate smoother Android application program development. This paper presents specifications and design of the query language and APIs of the platform, evaluate it, and discuss the results.