Department Publications

The safety of critically ill patients in intensive care units is an important aspect of medical care. Many human factors contribute to deficiencies and errors in patient care in the intensive care setting, such as long working hours, high levels of stress, lack of enough people, may cause human errors and affecting the effectiveness of the decisions of the physician. Several attempts have been made to increase the effectiveness of such decisions by issuing early alerts on adverse patient conditions. However, such alerts are based on single parameter variations, and not on the relationship between multiple parameter variations. We developed a computer-based model is an integrated solution which identifies adverse patient events based on multiple parameter variations, and then provides predictive treatment suggestions based on the likely clinical conditions which result in the parameter variations. The proposed system follows an interactive communication cycle in order to properly notify the responsible treating physicians at different tiers of responsibility. Our model is capable of early identification of adverse conditions and providing suitable treatment suggestions, thus acting as a decision support system to assist the treating physician.

Designing a PABX system using the existing power line infrastructure as the transmission medium is an effective method of implementing a fast and easily installable communication solution. The scope of this research is to develop such a system for a small scale organizational environment to avoid the complexities and time consumption of cable installation. As the power line transmission technique, we used narrowband frequency shift keying to counter the noise disturbances in power line. In addition we used a novel communication protocol to further reduce the effects of noise and to achieve reliable transmission. We integrated the switching function into the central unit which is the central control element in the system. We were able to achieve voice communication at the rate of 2kbps and to switch between four extensions. Further improvements in the voice quality can be achieved by using advanced noise …

In this paper, we address the problem of extracting objects in an image that conform to prior object shape knowledge. Major challenges include the judgment of scale and rotation parameters as well as tolerating occlusions and noise. We propose the use of a novel log polar domain mapping of the Cartesian domain image to efficiently and effectively overcome these. This method greatly simplifies rotation, scaling and provides an opportunity to incorporate a decision threshold. Whilst, the initial theoretical framework is developed on binary images, placement of this into the gray scale domain is achieved by incorporating a pre-processing binary segmentation step. A post processing Cartesian domain energy optimization is done to counteract discripancies caused at the initial stage. We demonstrate our results using several examples.

Three-wheelers are popular in Sri Lankan roads as a convenient mode of transportation. Presently there are about 500,000 registered three-wheelers. The range of commercially available electric vehicles are limited due to their battery weight and hence used mostly as neighbourhood vehicles. Three-wheelers are used mostly as neighbourhood vehicles and hence ideal for electrification. But no successful commercial electrically powered three-wheeler is available yet. Aerodynamic drag coefficient and rolling resistance coefficient are two basic parameters needed to determine the motor capacity of an electric vehicle. Accurate values of aerodynamic drag coefficient and rolling resistant coefficient are important to calculate accurate power estimate in electric vehicle design. In this paper we present an accurate method to determine the aerodynamic drag coefficient and rolling resistance coefficient of commonly …

The development and expansion of broadband technologies has stimulated the multimedia streaming market for the delivery of live streaming services which can be used for a variety of applications. The design of a generic audio and video streaming platform that can be employed for a wide range of applications is presented in this paper. A key feature of the platform is the ‘subscription framework’ which enables the service users to subscribe to a set of live feeds with their application specific requirements. The platform is capable of adjusting its service functionalities and the extent to which the media streams are secured for a particular user based on the requirements given at the service subscription. The platform is designed based on a layered architecture and a prototype implementation is carried out within the University network.

This thesis is about issues related to the security of electric substations automated by IEC61850, an Ethernet (IEEE 802.3) based protocol. It is about a comprehen sive security analysis and development of a viable method of auditing the security of this protocol. The security analysis focuses on the possible threats to an electric substation based on the possible motives of an attacker. Existing methods and met rics for assessing the security of computer networks are explored and examined for suitability of use with IEC61850. Existing methods and metrics focus on conven tional computers used in computer networks which are fundamentally different from Intelligent Electronic Devices (IED’s) of substations in terms of technical composition and functionality. Hence, there is a need to develop a new method of assessing the security of such devices. The security analysis is then used to derive a new metric scheme to …

• In some vision systems, the knowledge of the environment consist of a grid representation in which each object in the environment was represented by a 2D projection of its volume onto the horizontal plane. Such a representation is usually referred to as an “occupancy map”.

There are a few style-related and other items that are important. I list them in this document. Please use them when you write reports, and theses.

The hyperfine splittings of the 6P 3/2 state of indium (I= 9/2) have been measured for the first time using a two-step, two-color excitation scheme. These results provide a precise experimental test of new ab initio wavefunction calculations of three-valence-electron atomic systems such as indium and thallium. We first excite ground-state atoms in a heated quartz indium cell to the intermediate 6S 1/2 state using a blue (GaN) diode laser at 410 nm. By measuring the differential atomic vapor cell absorption of double-passed, second-order-diffracted beams from an acousto-optic modulator, we are able to stabilize the blue laser frequency to the sub-MHz level [M. Gunawardena et al., Rev. Sci. Instrum. 79. 103110 (2008)]. A second laser beam at 1291 nm overlaps the first in the vapor cell, exciting Doppler-narrowed hyperfine transitions to the 6P 3/2 excited state. By modulating the blue laser beam and using lock-in …

We are pursuing a series of precise atomic structure measurements in Group III elements--currently thallium and indium--designed to test recent ab initio theory calculations in these three-valence-electron systems [Phys. Rev. A 74, 022504 (2006); Phys. Rev. A 76, 022501 (2007)]. For thallium, independent atomic theory calculations are essential for atomic tests of discrete symmetry violation. In an experiment just completed, we used two-step, two-color laser excitation to measure the hyperfine constants of the 6P 3/2 excited state of indium (I= 9/2) for the first time. Currently we are pursuing a similar two-step excitation experiment in thallium to measure the isotope shift and hyperfine splitting in the 7P 1/2 excited state using a heated quartz vapor cell. In both experiments, the blue laser for the first excitation step is locked to its transition using a new scheme which makes use of an acousto-optic modulator. The thallium …

Research & Development of an Autonomous Mobile Robot "Transformer '08 to '09"for Tsukuba Challenge - Shibaura Institute of Technology Skip to main navigation Skip to search Skip to main content Shibaura Institute of Technology Home Shibaura Institute of Technology Logo English 日本語 Search content at Shibaura Institute of Technology Home Profiles Research units Research output Activities Press/Media Prizes Research & Development of an Autonomous Mobile Robot "Transformer '08 to '09"for Tsukuba Challenge Peshala Gehan Jayasekara , Shimon Ajisaka , Sousuke Nakamura , Takeshi Sasaki , Hajime Tamura , Hideki GHashimoto Functional Control Systems Research output: Contribution to journal › Article › peer-review Overview Original language English Pages (from-to) 1382-1384 Journal Default journal Publication status Published - 2009 Dec 26 Cite this APA Standard Harvard Vancouver Author …

Research on outdoor autonomous mobile robots has received much attention in the past decade. Outdoor autonomy meets with many challenges due to unpredictable dynamic environments, hard to control lighting and unavailability of resources. Nevertheless, such robots find a wide variety of potential applications in exploration, surveillance, agriculture, rescue missions and self-driven vehicles. This paper presents the authors’ approach to achieve long distance autonomous navigation with a mobile robot on outdoor cluttered pedestrian paths. The expected outcome was to finish “The Real World Robot Challenge”, an event held in the City of Tsukuba in Japan, by navigating a 1km course autonomously in a real environment with pedestrians and cyclists. Utilized hardware components and software architecture are illustrated. Furthermore, the strategies and other tactics to overcome context-based complexities are explained. The experimental results demonstrate the effectiveness of the system for outdoor autonomous navigation. Finally, the problems the authors faced in the real event are discussed.

This is a study done to assess the level of Informatization, simple definition of utilization of Information and Communication Technologies (ICTs), in the rural areas of Sri Lanka. The level of Informatization is measured as an index value. In the Asia Pacific region different types of Informatization Indices are calculated in different countries. In this study authors have defined a mechanism to calculate the Informatization Index for Sri Lanka, by considering the number of indices related to Informatization. This Informatization Index is calculated using 48 measures categorized under 11 sub components of ICT. Also a hypotheses testing based on an identified analysis framework is conducted in this study. According to the results obtained from this study, it was observed that in rural areas high utilization is there for utilization of Radio, Television, and Telephone. Mobile phone and Computer utilization is at a medium level. Level of utilization of ICT also varies with the demographic factors also.

Estimation of the location of a Mobile Station accurately is a key requirement to effectively provide a wide range of Location Based Services over mobile networks. Hence developing cellular positioning techniques has been a key research problem, with numerous localization solutions been proposed. These include technologies such as Cell ID, angle and time of arrival methods, statistical methods and fingerprinting methods. This paper presents fingerprinting based positioning techniques suitable for outdoor and indoor positioning. Multiple positioning techniques were proposed, implemented and evaluated with outdoor and indoor trials. The ultimate solution proposed in this paper is not a single positioning technique; rather it presents several positioning techniques that achieve optimum performance in each test environment. The results reports 67% positioning error as 112 m, 299 m and 221 m for urban …

In this paper EOG signal processing and developing a low cost signal interface for wheelchair with high accuracy and reliability for severely disabled people is presented. Here the signal processing is done on a microcontroller which reduces the cost drastically rather than using a computer. Eye movement is detected by processing EOG signal, and associates the eye movement to motion commands of the wheelchair such as forward, reverse, left and right. A 99% accurate classification has been demonstrated experimentally.

Bluetooth is a high end wireless technology designed for short range communications with high means of integrity. The application of Bluetooth technology for remote monitoring and control is an evolving concept in automation. However, in these applications, the controller which is controlled via Bluetooth technology or the sensor which transmits the sensed values via Bluetooth technology is application-specific. On the other hand, more productivity can be achieved by making the module general purpose, such that it can be used for wide range of applications. In fact, the general purpose concept can be applied to a selected set of devices with standard data interfaces, by making the system general purpose to the developer rather than the end user. In this work, a general purpose controlling module is designed with the capability of controlling and sensing up to five devices simultaneously. The communication …

We present a simple method for diode laser frequency stabilization that makes use of a Doppler-broadened vapor cell absorption signals of two frequency-shifted laser beams. Using second-order-diffracted, double-passed beams from an acousto-optic modulator, we achieve a frequency separation roughly equal to the Doppler half width. The differential transmission signals of the two beams provide an error signal with a very large linear feature, allowing frequency stabilization over a range of greater than 1 GHz by means of standard proportional-integral-derivative servo feedback to the piezoelectric control of the grating in our external cavity diode laser. We have applied this technique to two different diode laser systems, one used to lock to the 410 nm E1 transition in indium and another for locking to the M1/E2 transition in thallium at 1283 nm. In both cases the technique reduces frequency fluctuation to roughly 1 …

This paper details the use of decision fusion from the outputs of different types of classifiers used for analyzing network traffic to detect masquerading within an IEC61850 automated substation. Data on network traffic is collected under simulated scenarios of a genuine user casually browsing data and an attacker rapidly downloading restricted data. The logarithm of the time difference between two successive packets is calculated and the histogram of this is used for classification using support vector machines and nearest neighbor classifiers. Decision fusion of the outputs of the best classifiers is done using evidence theory and possibility theory in order to reduce the number of input data and increase the reliability.

This paper presents a case study of the application of security metrics to a computer network. A detailed survey is conducted on existing security metric schemes. The Mean Time to Compromise (MTTC) metric and VEA-bility metric are selected for this study. The input data for both metrics are obtained from a network security tool. The results are used to determine the security level of the network using the two metrics. The feasibility and convenience of using both metrics are then compared.

The paper presents the combined application of Geographical Information Systems (GIS), the Global Positioning System (GPS), the General Packet Radio Service (GPRS) and the Internet for tracking of vehicle fleets. It is one component of an enterprise solution that is designed to manage and track a large fleet. The key features of the system are an open-source GIS platform, real-time location information update, and a web-based user interface. The system consists of GPS-based vehicle tracking devices, a communications server, a web-server, a database server, and a map server. The tracking devices mounted in the vehicles collect location information in real-time via the GPS. This information is transferred continuously through GPRS to a central database. The users are able to view the current location of each of the vehicles in the fleet via a web-based application, and thereby manage the fleet. The vehicle positions and other related information are displayed on a digital map, which is made available by a map server.

The objectives of this research are to assess the impact of ICT on learning and teaching in secondary schools in Sri Lanka, to assess the current ICT usage in schools, and to derive a set of recommendations that would help future policy making. The research found that there is no direct relationship between the computer usage of students and their perceived impact of ICT on learning. Both studentspsila and teacherspsila attitude toward the usage of ICT for learning and teaching purposes are statistically-significant and positively-related to their perceived impact. However, the relationship between ICT skills and their perceived impact of ICT on learning was comparatively more significant for students than teachers and principals. Government interventions on training are not related to the perceived impact of ICT of teachers and principals. Furthermore, research found that the mere presence of ICT infrastructure in …

This paper presents non linear automatic unmanned aerial vehicle (UAV) control simulation with high maneuverability and precise tracking. Major considerations of flight performance and precise tracking have been evaluated with software simulation by aerosonde UAV. The autonomous control system is based on the Aerosonde UAV with control theory previously developed and implemented into aircraft. Major requirements for the high maneuverability are good path following with minimum overshoot, settling time without oscillation and low coupling between high level commands. High maneuverability leads to precise tracking for any kind of application. A MATLAB reg standard configuration environment and the Aerosim reg Aeronautical Simulation Block Set are utilized for simulation studies and presented through a Flightgear reg interface.

In this paper, we present a novel strategy to detect the slipping of an object grasped by a human hand. The recognition of slipping of a grasped object early plays a significant role in designing the dexterous robotic hands to ensure a firm grasping. Here, we present a system that uses force sensors embedded in a tight glove to capture force variations during a slipping of a grasped object. The analysis of contribution by five fingers and the palm for grasping is presented based on new factor called contribution factor. Also, we propose a new direction to incorporate controlling of dexterous robot hands based on spatial activity of force exerted by hand to ensure a firm grasping.

This paper discusses the design of a centralized control and monitoring system for railway traffic that can be implemented on top of the existing control logic (interlocking system) of Sri Lanka railways. The overall solution comprises of a central server system and databases with redundancy, relay house hardware unit (with embedded Ethernet and a custom communication protocol for microcontrollers) to interface with the relays of the interlocking system, Dispatchers Controlling Interface for remote monitoring and controlling, and a TCP/IP network which interconnects all the above mentioned components of the total system. The current centralized traffic control (CTC) system in Sri Lanka, located at Maradana, was implemented in the year 1985. This has manually operated switch boards, a relay based operation (separate relays for controls and indications) having every switch hardwired to the relays which are …

Testing of wireless sensor network protocols can be tedious for large networks when mobility is added. Mainly because these networks involve a large number of nodes scattered in an ad-hoc configuration. Although there are several publicly available static sensor network testbeds, testbeds where mobility is facilitated are very rare. One of the main objectives of this work is to provide a general hardware platform, which supports to implement different protocols for mobile sensor networks. The testbed is implemented with one base station node, one mule and five sensor nodes, where data mules move in a random manner through a community of fixed sensor nodes. As the mule comes within range of each sensor node, it collects the available data. After collecting data from all the sensor nodes, the mule returns to a central node, where it uploads all the data collected. The motes are connected to the central node …