Seongju Chang

A HYBRID SYSTEM FOR DAYLIGHT-RESPONSIVE LIGHTING CONTROL

Capability is provided to dynamically reallocate the multiplex data stream from one communication channel to a plurality of communication channels. This allows increased flexibility in responding to degradation of the main communication channel and in accommodating increased user demand exceeding the capacity of the main channel. A table is generated to control the DTE PORTs accessed during each slot of a multiplexer frame. A separate table is generated to control the allocation of multiplex data between communication channels. Both tables are generated based upon a common Hash table. A plurality of Hash tables correspond to different output data rates and permit the output rate of the multiplexer to coincide with the maximum output rate capacity of an associated transmission device such as a modem.

What is an intelligent building? Analysis of recent interpretations from an international perspective

In recent years, the notion of intelligent buildings (IBs) has become increasingly popular due to their potentials for deploying design initiatives and emerging technologies towards maximized occupants’ comfort and well-being with sustainable design. However, various definitions, interpretations, and implications regarding the essence of IBs exist. Various key performance indicators of IBs have been proposed in different contexts. This study explores the notion of IBs and presents an analysis of their main constituents. Through a comparison of these constituents in different contexts, this study aims to extract the common features of IBs leading to an evolved definition which could be useful as a reference framework for design, evaluation, and development of future IBs. Findings also scrutinize the long run benefits of IBs, while demonstrating the constraints and challenges of the current international interpretations.

Ubi-Floor: Design and Pilot Implementation of an Interactive Floor System

Ubi-floor is designed as an interactive floor system which allows user to interact with a floor based smart environment. Concerning context aware floor system, previous researches typically dealt with simple ideas of using gate pattern recognition supported by piezoelectric sensing devices or personal identification mediated by body weight estimation that cannot fully support position dependent context-awareness not to mention interactive interfaces based on it. This paper describes the design and implementation of an interactive floor system that is capable of dealing with various context aware multimedia applications such as visual displays, floor based games, navigation through geographical maps and recording or playing video memo triggered by the menu selections through foot step tracking interface. In addition, this pilot system is recognized as a highly scalable modular prototype of an innovative digital floor system applicable to diversified ubiquitous environments. Furthermore, the system is likely to provide highly enhanced usability of a smart floor system largely affected by various applications that could be adopted. Our further study will include the integration of this ubi-floor platform with various applications in the domain of ubiquitous computing.

High-Resolution Touch Floor System Using Particle Swarm Optimization Neural Network

A touch floor system, based on force sensitive resistors, capable of identifying user position and motion with high resolution, is proposed in this paper. A particle swarm optimization-based neural network (NN), initialized with the output of a Levenberg-Marquardt-based NN, allows inaccuracy drawbacks of the trilateration method in position estimation due to sensors nonlinearity to be reduced to one fifth under non-stationary conditions. Furthermore, position-tracking accuracy is improved by a Kalman filter and a motion recognition algorithm is suggested for mimicking computer mouse clicks. Experimental results show non-uniformly sized icons displayed with high-resolution coordinates can be selected on the floor by the participants of diversified weights. This proves the feasibility of a high-resolution touch floor interface scalable for large area, by facilitating digitally mediated human-architecture interactions.

Modularized multimedia framework for multi-modal and multi-functional interactions

Smart Architectural Surface is a novel and highly integrated planar construct for diversified smart home services with networked smart cell units equipped with various sensing, cognition and actuation capabilities that would allow run-time polymorphism as the basis for functional changes for various event-driven operation scenarios. The SAS system can demonstrate the outcomes of collective intelligence that are mediated by various multi-modal interactions. Current SAS prototype is capable of polymorphous functional changes for dynamically adjustable electronic wallpaper, location/distance-aware video conferencing, personalized information browser, and automatic responses to various unintended events. Future applications would harness machine learning and machine vision techniques and will explore the advantages of having computational ecology of its digital modular units constituting smart wall system for multi-modal and multi-functional interactions.

Auto-localized multimedia platform based on a modular Cyber Physical System aligned in a two-dimensional grid

In this research, a smart mechanism to automatically configure the relative locations of clustered intelligent nodes arranged in a grid pattern is introduced. If an intelligent node knows the relative location of more than one neighboring node, its location can be recognized. By studying the feature of the grid structure and the short-range infrared signal communication method between the adjacent nodes, the location of an intelligent node and the location map construction of the whole system are configured automatically at each node. The algorithms in this study are tested by a cross-module image or video display task with modularized and reconfigurable digital surface, a modular Cyber-Physical System platform which has stacked ‘smart modules’ each of which has smart sensing and multimedia node with infra-red transceivers at four corners. Exemplary applications demonstrate the feasibility of the system in its scalability and practicality as well as performance by being applied to various spatially reconfigurable multimedia platforms.

Numerical analysis to determine the performance of combined variable ceiling and floor-based air distribution systems in an office room

This study analyses the performance characteristics of combined variable ceiling and floor-based air distribution systems in an office room using a numerical method to optimize the level of thermal comfort and indoor air quality. To validate the computational fluid dynamics simulations, temperature, air velocity and CO2 concentration were measured and compared. The simulation results of various combinations of ceiling and floor-based air distribution systems show that the exhaust should be located above the occupant and the window in summer; due to the large thermal plume as heat sources that could be generated by the window and the occupant. Whereas in winter, the supply should be located on the ceiling far from the window and the exhaust should be positioned on the floor near the occupant; as the downward airflow around the cold window surface would become more dominant when compared to the upward airflow associated with any other heat sources. The results have indicated that having both ceiling and floor-based air conditioning systems would allow the flexibility to change supply and exhaust air diffuser locations to optimize thermal and ventilation performance more efficiently in countries that are subject to distinct seasonal changes.

I-sphere: a virtual reality based 3D interactive web navigation interface

This research explores a novel hybrid interface which dynamically links a virtual reality based 3D interface object with multiple hypertext webpages. The tree or network structured 3D graphic object named I-Sphere, consists of multiple nodes and links which intuitively represents the entire 3D navigational space of a site so that the user is aware of his/her navigational position in the web search space at all times. This user operable 3D web search visual interface would give a more intuitive and information rich control over the entire search space to assist highly interactive online information navigation. I-Sphere development process follows a user centric design methodology. A prototypical 3D web search interface was conceptualized and test-built. Finally an instance of the developed interface was employed over a context and tested for usability issues.

Application of Matrix Pencil Algorithm to Mobile Robot Localization Using Hybrid DOA/TOA Estimation

Localization plays an important role in robotics for the tasks of monitoring, tracking and controlling a robot. Much effort has been made to address robot localization problems in recent years. However, despite many proposed solutions and thorough consideration, in terms of developing a low-cost and fast processing method for multiple-source signals, the robot localization problem is still a challenge. In this paper, we propose a solution for robot localization with regards to these concerns. In order to locate the position of a robot, both the coordinate and the orientation of a robot are necessary. We develop a localization method using the Matrix Pencil (MP) algorithm for hybrid detection of direction of arrival (DOA) and time of arrival (TOA). TOA of the signal is estimated for computing the distance between the mobile robot and a base station (BS). Based on the distance and the estimated DOA, we can estimate the mobile robots position. The characteristics of the algorithm are examined through analysing simulated experiments and the results demonstrate the advantages of our method over previous works in dealing with the above challenges. The method is constructed based on the low-cost infrastructure of radio frequency devices; the DOA/TOA estimation is performed with just single value decomposition for fast processing. Finally, the MP algorithm combined with tracking using a Kalman filter allows our proposed method to locate the positions of multiple source signals.

Consensus Achievement of Decentralized Sensors Using Adapted Particle Swarm Optimization Algorithm

This paper explores the possibility of enhancing consensus achievement of decentralized sensors by establishing cooperative behavior between sensor agents. To these ends, a novel particle swarm optimization framework to achieve robust consensus of decentralized sensors is devised to distribute sensing information via local fusing with neighbors rather than through centralized control; the new framework showed a 16.5 percent improvement in consensus achievement as compared to the classic majority rule method. Noteworthy enhancements in consensus achievement are also pertinent to the comparable situation of decentralized sensor systems.