Kyuchang Kang

A wearable context aware system for ubiquitous healthcare.

Recent developments of information technologies are leading the advent of the era of ubiquitous healthcare, which means healthcare services at any time and at any places. The ubiquitous healthcare service needs a wearable system for more continual measurement of biological signals of a user, which gives information of the user from wearable sensors. In this paper, we propose a wearable context aware system for ubiquitous healthcare, and its systematic design process of a ubiquitous healthcare service. Some wearable sensor systems are introduced with Zigbee communication. We develop a context aware framework to send information from wearable sensors to healthcare service entities as a middleware to solve the interoperability problem between sensor makers and healthcare service providers. And, we propose a systematic process of design of ubiquitous healthcare services with the context aware framework. In order to show the feasibility of the proposed system, some application examples are given, which are applied to remote monitoring, and a self check service

UPnP AV architectural multimedia system with a home gateway powered by the OSGi platform

The key issue of multimedia systems in home network environment is interoperability among different kinds of multimedia devices. And, as for multimedia content providers outside a home, another issue of multimedia systems in home network environment is how to provide the multimedia service from the outside of a home. We developed a UPnP AV architectural multimedia system with a home gateway powered by the OSGi platform, which gives interoperability among multimedia home devices in home network environment, and a powerful tool for multimedia content providers to provide smarter multimedia service for users in a home.

Unsupervised learning for human activity recognition using smartphone sensors

Abstract To provide more sophisticated healthcare services, it is necessary to collect the precise information on a patient. One impressive area of study to obtain meaningful information is human activity recognition, which has proceeded through the use of supervised learning techniques in recent decades. Previous studies, however, have suffered from generating a training dataset and extending the number of activities to be recognized. In this paper, to find out a new approach that avoids these problems, we propose unsupervised learning methods for human activity recognition, with sensor data collected from smartphone sensors even when the number of activities is unknown. Experiment results show that the mixture of Gaussian exactly distinguishes those activities when the number of activities k is known, while hierarchical clustering or DBSCAN achieve above 90% accuracy by obtaining k based on Calinski–Harabasz index, or by choosing appropriate values for ɛ and MinPts when k is unknown. We believe that the results of our approach provide a way of automatically selecting an appropriate value of k at which the accuracy is maximized for activity recognition, without the generation of training datasets by hand.

Home server for home digital service environments

This paper proposes a new scheme of the home server platform for providing home digital services by connecting home networks and the Internet. The proposed scheme is an integrated form of a home multimedia server, a home control server, and a home information server. The proposed system has an interface between access networks and home networks, various kinds of wired and wireless home networks devices, and multimedia processing modules. As examples of home digital services, the system provides a digital TV service, a remote multimedia service, and an instant message service based on the open service gateway initiative (OSGi) framework. We have implemented the proposed home server scheme, and verify that the system can be a core device of the home digital service environments.

A Systematic Design Tool of Context Aware System for Ubiquitous Healthcare Service in a Smart Home

Recent developments of information technologies are leading the advent of the era of ubiquitous healthcare service, which means healthcare services at any time and at any places. In a home, the ubiquitous healthcare service requires some context aware system for smart services using home network. In this paper, we propose a systematic design tool of a context aware system for ubiquitous healthcare service in a smart home, which is composed of a home gateway, a home server, a PDA, home network healthcare devices, and wearable sensors. We developed a context aware framework to send information from wearable sensors or healthcare devices to healthcare service entities as a middleware to solve the interoperability problem among sensor makers and healthcare service providers. And, we propose a design tool of ubiquitous healthcare services with the context aware framework in a systematic way. In order to show the feasibility of the proposed system, an application example is given, which is applied to a self check service.

Implementation of management agents for an OSGi-based residential gateway

This paper presents a concept of management agent and its implementing approach in an OSGi-based residential gateway. The role of management agent has been defined by OSGi (Open Service Gateway initiatives) alliance but the detailed interfaces have not been specified yet. In this paper, we propose servlet-based management agents and implement them to support their roles defined by OSGi specification. Implemented management agents consist of small function component, thus these can be extended easily according to the change of OSGi release.

N-screen service using I/O Virtualization technology

Improvement of computing devices caused a wide range of changes in our life with new technologies such as cloud computing and n-screen. Virtualization is at the center of these challenges and here we approach N-screen service based on the I/O Virtualization. To support seamless screen of a personal computing, we virtualized individual screen devices to be plugged into the remote OS. Here we suggest a framework that provides OS virtualization and I/O virtualization as well as Softbus protocol that empowers frame buffer translation.

Lifelog agent for human activity pattern analysis on health avatar platform.

Objectives To provide accurate personalized medical care, it is necessary to gather individual-related data or contextual information regarding the target person. Nowadays a large number of people possess smartphones, which enables sensors in the smartphones to be used for lifelogging. The objective of the study is to analyze human activity pattern by using lifelog agent cooperating with the Health Avatar platform. Methods Using the lifelog measured by accelerometer and gyroscope in a smartphone at a 50 Hz rate, the agent reveals how long the user walks, runs, sits, stands, and lies down, and this information is summarized by hours. The summaries are sent to the Health Avatar platform and finally are written in the Continuity of Care Record (CCR) format. Results The lifelog agent is successfully operated with the Health Avatar platform. In addition, we implement an application that displays the users activity patterns in a graph and calculates the metabolic equivalent of task based calorie burned by hour or by day using the lifelog of the CCR form to show that the lifelog can be used as medical records. Conclusions The agent shows how lifelogs are analyzed and summarized to help activity recognition. We believe that our agent demonstrates a way of incorporating lifelogs into medical care and a way of exploiting lifelogs in a medical format.

Management system for OSGi-based infrastructure

This paper describes a remote management system and its implementation to control and manage the OSGi-based infrastructure such as residential gateway, telematics terminal, or other embedded devices. The features of implemented management system include dynamic service, user interface, and static package tracking. In order to provide inter-operation between relevant entities such as a remote manager and a management agent, we design XML-based communication message. The management system described in this paper provides a simple foundation for a service provider to deliver and manage a wide range of a managed e-service based on the OSGi infrastructure

A novel real time video tracking framework using adaptive discrete swarm optimization

A new adaptive discrete swarm optimization (ADSO) is proposed for video tracking.ADSO shows high accuracy rate and fast tracking and relocating speed.Error rate is reduced to 70.21% of Particle Swarm Optimization (PSO).Processing time per frame is reduced to 58.6% of PSO. This paper has proposed a new adaptive discrete swarm optimization (ADSO) for the video tracking framework. Each target object is first presented by a search window with four-dimensional features, which include 2D coordinates of the search window, its width and height. The image in the search window of a target object is extracted to calculate the HSV histograms, which are used to establish a feature model for the target object. Then the particles fly in a sub-search-space to find an optimal match of the target. If any occlusion or disappearance of the target object is detected, the particles will adaptively update their searching strategies in order to recapture the target. The experimental results demonstrate that the ADSO can out-perform the traditional PSO algorithm in the aspects of high accuracy rate and fast tracking and relocating speed.