Browsing by Author "Ozawa, S."

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Assessing the potential of satellite and ground spectral data for Chlorophyll-a monitoring in Lake Kasumigaura, Japan
(IEEE, 2014) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
The suitability of a handheld spectrometer and ASTER satellite data for monitoring Chlorophyll-a (Chl-a) in Lake Kasumigaura, Japan was tested in July 2010 to December 2013. ASTER based Chl-a retrieval algorithms were developed support with in-situ Chl-a, MODIS OC3 Chl-a and Kakemaoki and Koshin automated water quality monitoring stations Chl-a. ASTER VNIR band ratio were regressively analyzed with the corrected MODIS Chl-a and automated station values obtained for each ASTER date on a day by day basis. The regression equation of the ASTER band ratio (B1/B2), with highest correlation was used to generate high-resolution Chl-a distribution maps. Significant correlation between the ratio of the reflectance peak at 705 nm and the Chl-a absorption at 678 nm and the in-situ Chl-a content was observed and these reflectance ratios were used to establish spectrometric Chl-a estimation algorithms. Proposed algorithms can be successfully adopted to determine localized environmental effects in the Lake.
Change detection in the channel segment of Negombo Estuary, Sri Lanka using time series satellite data and its possible impacts on estuarine productivity
(The Asian Fisheries Society, 2011) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
CHLOROPHYLL-A MONITORING IN SRI LANKAN ESTUARIES USING ALOS/ANVIR-2 DATA
(International Geo Science and Remote Sensing symposium, 2012) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
Coastal water body database to monitor the water quality and land use changes from remote sensing data
(Remote Sensing Society of Japan (RSSJ), 2012) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
Comparison of three chlorophyll-a estimation approaches using ASTER data acquired over Sri Lankan coastal water bodies
(Malaysian Journal of Remote Sensing & GIS (MJRS&GIS), 2015) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
In the present study, we compare the following Chlorophyll–a (Chl-a) estimation algorithms using ASTER data acquired over Sri Lankan coastal water bodies: (1) the simple band-ratio algorithm with simple atmospheric correction using dark object subtraction (DOS); (2) the single band-ratio algorithm with radiative transfer-based atmospheric correction using ENVI’s FLAASH software including MODTRAN; and (3) our previously proposed algorithm based on combinations of ASTER and corrected MODIS Ocean Color-3 (OC3) data. First, several ASTER band ratios were regressively analyzed with in-situ Chl-a data acquired from the Negombo estuary and Puttalam lagoon in the west coast of Sri Lanka, and the band ratio with the highest correlation was selected. Then, time-series Chl-a distribution maps with the spatial resolution of ASTER/VNIR (15 m) were generated using the above three methods, and compared with the in-situ Chl-a data. Based on the result obtained, the FLAASH and ASTER/OC3 based methods showed high correlation with the in-situ Chl-a values (R2 = 0.96 and 0.92 respectively), while the DOS based method showed low correlation (R2 = 0.61), which indicates that the ASTER/OC3 based method will give equivalent performance to the FLAASH based method even though it does not need user-based atmospheric correction like the DOS and the FLAASH based methods.
Continues monitoring of environmental radioactivity in the area polluted by the Fukushima Nuclear Power Plant Accident 2011 and disclosure of the data to public through the Internet
(Department of Zoology and Environmental Management, University of Kelaniya, Kelaniya, Sri Lanka., 2016) Fuse, M.; Miura. S.; Ozawa, S.
The Internet has become a powerful communication media. In authors’ previous paper, it has been shown that the Internet can be a good risk communication tool in panic situations caused by natural disasters. The present paper deals with the role of the media in the recovering process from the disaster. It is five years since the earthquake of the magnitude 9.0 occurred at the bottom of the Pacific Ocean near the coast of Northern Japan. There occurred nuclear accidents triggered by the tsunami at the Fukushima Nuclear Power Plants (FNPP). They experienced wide range of radioactive contaminations. Many people had to evacuate from the polluted lands. Even today, about 100,000 people in the Fukushima Prefecture cannot come back to their home lands. The National Institute of Technology, Fukushima College (NITFC) is located at 40km south of the FNPP. About 100 students (10% of total students) had their home lands in the risky 30km region from the FNPP. Some staffs and students of NITFC have been monitoring the radioactivity of their environment since just after the accident and they continued to open their data to public through the Internet. This paper discusses influence of giving different source data to the public beside the official governmental data regarding the radioactivity of the environment.
Development of a Job Control System to Optimize Web Traffics
(2007) Fernando, S.; Dalugama, J.; Jayasekera, R.; Dassanayake, G.; Patu, V.; Minato, A.; Ozawa, S.
Development of coastal water body database on KISSEL server
(IEEE, 2012) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
Monitoring of coastal water bodies in all the relevant aspects was highly important for the sustainable use of those. To achieve this all the research findings should be easy access and presenting those in a user friendly manner will be more advantage. In Sri Lanka, there was not fully or never developed database on research findings especially on coastal water bodies. Thus we developed a Sri Lankan coastal water body database (CWBDS) on KISSEL server system which can be benefitted all the interest communities including general public. Presently it include water quality data over two decades of lagoons and estuaries and in near future it will update with support from universities and research organizations including research on biodiversity, fisheries, land use, socio economics, topography, water circulation, pollution etc.
Development of E-learning community in Asia Pacific countries
(Faculty of Social Sciences, University of Kelaniya, 2009) Dasanayake, G.; Vaise, P.; Minato, A.; Warnajith, N.; Wijayanayake, J.; Ozawa, S.
Development of E-learning community in Asian Pacific countries
(University of Kelaniya, 2008) Dassanayake, G.; Vaise, P.; Minato, A.; Ozawa, S.
Eutrophication Trends in Bolgoda North Lake, Sri Lanka
(Department of Zoology, University of Kelaniya, Kelaniya, Sri Lanka, 2014-06) Perera, B.D.C.; Wijeyaratne, M.J.S.; Dahanayaka, D.D.G.L.; Tonooka, H.; Minato, A.; Ozawa, S.
Chlorophyll-a (Chl-a) concentration in the Bolgoda North Lake (06.400 – 06. 480 N; 079. 550 -079. 580 E), which is a shallow brackish water body situated in the western coastal region of Sri Lanka, was determined through correlating Advanced Space-borne Thermal Emission and Reflection Radiometer (ASTER) optical sensor data with in-situ data measured from April 2013 to October 2013 in 05 sampling sites. ASTER band ratio of B1/B2 which gave the highest correlation with in-situ Chl-a data was used to generate 15 m resolution Chl-a distribution maps. Chl-a distribution maps generated using ASTER data indicated that most areas of Bolgoda North Lake were eutrophic. Some regions of the Weras Ganga which flows into the Lake showed very high Chl-a concentrations during April indicating hypereutrophic conditions while in June, September and October these areas indicated eutrophic conditions. Observations on land use pattern revealed that industrial zones border these areas. High Chl-a concentrations were also observed in the areas bordered by the lands with low income houses from which household waste as well as sewage are discharged directly to the lake. Chl-a distribution maps developed for 2005, 2008, 2010 and 2011 revealed that eutrophication of the Bolgoda North Lake has gradually increased in the recent past. This may possibly be due to the increase in the industrial effluents as a result of industrial development in the area and also due to increased population of low income groups that live in some areas bordering the lake.
Evaluation of Chlorophyll retrieval algorithm using an intermittently closed tidal estuary: The Chilaw lagoon in the west coast of Sri Lanka
(Remote Sensing Society of Japan (RSSJ), 2011) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
Feasibility Study for the Estimation of the Chlrophyll-a Using ASTER Data in an Eutrophic Lake, Sri Lanka
(Japan Geoscience Union, Japan., 2014) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
The objective of this study is to evaluate the performance of the previously proposed band ratio approach in estimating Chl-a in Bolgoda Lake, Sri Lanka as a representative example of Case II waters. Lake is located at western province in an area with lot of industries and also with some agricultural activities. Considerable amount of industrial effluents are discharged into it. Illegal filling and also encroachment has occurred in the recent past. This study focused on to determine the trends in eutrophication via Chl-a changes during the recent past, make predictions and recommend mitigatory measures and suggest precautionary measures to restore the environment. From March to December 2013, water samples at 5 points of Lake were collected once per month parallel to ASTER overpass and Chl-a of each sample was measured using a laboratory spectrophotometer. Cloud-free ASTER scenes acquired over Lake under clear sky conditions were selected during 2000 to 2013 for Chl-a estimation and trend analysis. All the ASTER images were atmospherically corrected using FLAASH and in-situ Chl-a data on Lake were regressively analyzed with atmospherically corrected three ASTER VNIR band ratios such as B1/B2 of the same date. Finally, the regression equation of the band ratio with highest correlation (B1/B2; R2 = 0.78) was used to develop algorithm for generation of 15-m resolution Chl-a distribution maps using atmospherically corrected time series satellite imageries in day by day basis. This method applied for ASTER band 1/2 ratio due to Chl-a is positively correlated with the green band reflectance and negatively correlated with the red band reflectance. Therefore, the reflectance ratio of green and red bands becomes a robust parameter to estimate the Chl-a content. According to the ASTER based Chl-a distribution maps it is clearly evident that eutrophication of the Bolgoda Lake has been gradually increased from 2005-2011. Further, results showed that there were significant eutrophic conditions throughout the year 2013 in several parts of the Lake and considerable spatial heterogeneity with higher concentrations being recorded water stagnant areas and in water adjacent to freshwater outlets. It is clear that Bolgoda Lake is apparently a disposal site of various discharges of factories in addition to poor drainage and sewage systems present in this area. Highly unplanned urbanization and absolutely lack of adequate waste disposal management facilities in industries close to Lake have resulted in pollution of water. If the present trend of waste disposal and unplanned urbanization continue, they would create enormous environmental problems in future. Results of the present study showed that information from satellite remote sensing can play a useful role in determining the changes in Chl-a related to eutrophication in Bolgoda Lake and in the development of time series Chl-a distribution maps. Such information is important for the future predictions, development and management of this area as well as in the conservation of biodiversity. Therefore we recommend incorporation with this technique for routine monitoring of water quality using multi satellite data such as ASTER in inland water bodies like Bolgoda Lake in the future.
ICT for Sustainable Growth in the World
(Department of Zoology, University of Kelaniya, Kelaniya, Sri Lanka, 2014-06) Dassanayake, G.; Warnajith, N.; Minato, A.; Itaba, M.; Ozawa, S.
Information and Communication Technologies (ICTs), including satellites, mobile phones or the Internet, play a key role in addressing the major challenges related with climate change and sustainable development. ICTs can play a significant role to improve the carbon footprint of cities by moving to a more intelligent use of energy. Climate change has risen rapidly up the agenda of international organizations, governments, communities, universities and industry sectors in the past decade, reflecting the growing impact of climatic manifestations at multiple levels with the potential to become a major disruptive factor in the achievement of economic growth and development over the next fifty years, climate change is playing an increasing role in processes of policy design, strategy implementation, livelihood maintenance and business practices around the world. This paper aims to raise awareness of the need to design and implement strategies for the ICT sector to better prepare for, respond and adjust to the impacts of short-term and long-term climatic manifestations. It gives an overview of the importance of adaptation for the ICT sector and of the challenges and opportunities resulting from this adaptation. It also describes the ICT sector's current response to climate change and gives a list of suggested adaptation actions. ICTs are fundamental for monitoring climate change, mitigating and adapting to its effects and assisting in the transition towards a green economy. By raising awareness of the role of ICTs, it is promoting transformative solutions that can ensure a sustainable future for all.
Image Processing Approach for Ancient Brahmi Script Analysis
(University of Kelaniya, 2015) Warnajith, N.; Bandara, D.; Bandara, N.; Minato, A.; Ozawa, S.
Writing is one of the most important inventions of Humankind. There are few main languages in the ancient world. Among these ancient languages Sanskrit was used in Indo region. Brahmi script is one of the most important ancient letters in South Asia. It became the matrix of Debanagaricharacter used for Sanskrit and Hindi. And, it produced Burmese script, Khmer script, Thai alphabet, Laotian alphabet, Tibetan alphabet, etc., during the last two thousand years. The people of Sri Lanka are fortunate that some of the writing of their ancestors is preserved on various inscriptions found throughout the country. These inscriptions have been discovered under the drip ledges of caves, rocks, pillars and slabs. Inscribed gold, silver and copper plates have been discovered as well. On the decipherment of these inscriptions, historical, linguistic and paleographical conclusions could be arrived at. The source data of this study is already published grayscale images of early Brahmi script. These images are taken from the paper copies of inscriptions called as estampages (rubbed copy). Up to the present, reading and analyzing these inscriptions are done by manually. The aim of this study is to develop algorithms based on image data of these estampages and implement a digital data repository. The process of this study can be divided into few stages. Such as: (1). Producing precise alphabet fonts of early Brahmi scripts has been produced from photographic data, (2). Precise method of identification of ancient letters with the aid of the alphabet fonts, which leads to automatic reading of ancient inscriptions by computers, (3). Database implementation for the analysis, (4). Develop web based interface for scholars over KISSEL network to share the knowledge and experience among the KISSEL users.
Improvement of Text-based E-learning Contents by Using a New Multimedia-type Web Authoring Tool - A case study from a Sri Lankan University
(2007) Dassanayake, G.; Patu, V.; Fernando, S.; Jayasekera, R.; Minato, A.; Noguchi, H.; Ozawa, S.
Inexpensive Sensor Network Solution for Environment Monitoring
(Department of Zoology, University of Kelaniya, Kelaniya, Sri Lanka, 2014-06) Warnajith, K.N.S.; Lakesh, S.H.P.K.; Minato, A.; Ozawa, S.
Sensor Networks are designed for specific applications which range from small-size healthcare systems to large scale environmental monitoring systems. The design of sustainable sensor networks is a very challenging issue. With the aid of rapid development of the modern technology, commercial equipments for monitoring environment factors have been introduced so frequently. However, the cost of these equipments becomes the main problem when developing a sensor network. Also, energy consumption of these equipment is another problem. In this paper, these factors were considered and a sensor network implementation which uses small low cost Linux board (Raspberry Pi) and low cost sensors was introduced. A small microcontroller was used as the interface between the sensor and the Linux Board and the functionality of this microcontroller was also discussed. This was tested for recording CO2 content, temperature and spectrum data. A practical method for continuous power supply for the developed system was also described and application in large scale environment was also proposed.
Integration of multisource data for chlorophyll-a monitoring in Negombo estuary, Sri Lanka
(IEEE, 2011) Dahanayaka, D.D.G.L.; Tonooka, H.; Wijeyaratne, M.J.S.; Minato, A.; Ozawa, S.
In order to estimate chlorophyll-a concentration (Chl-a) for tropical coastal estuarine environments using satellite optical sensor, observations were conducted from 1987 to 2009 in Negombo estuary, Sri Lanka, with support with available in-situ measurements. Landsat band ratios were regressively analyzed with available in-situ Chl-a data. This relationship was used for correcting MODIS OC3 Chl-a values, and then ASTER band ratios were regressively analyzed with the corrected MODIS values. The regression equations obtained for ASTER and Landsat were used to develop algorithms for generation of 15m and 30m resolution Chl-a distribution maps, respectively, in Negombo estuary using atmospherically-corrected time-series imageries. The results indicate that some parts of the estuary have increased eutrophication conditions during 1987-2009.
Message formation and message transfer
(University of Kelaniya, 2008) Ozawa, S.; Dassanayake, G.; Patu, V.; Itaba, M.; Minato, A.
Mobile Applications for Language Education in the Pacific
(Department of Zoology and Environmental Management, University of Kelaniya, Kelaniya, Sri Lanka., 2016) Ualesi, E.T.; Ozawa, S.
The rapid developments and usage of mobile apps worldwide prompts the idea of producing a mobile app particularly for language education. This study shows the development of a basic language education app to assist learners who are interested in learning some of the Pacific Languages. Most islanders living abroad cannot speak their native languages fluently especially the young children. Nowadays, nearly every person has access to mobile devices and it is not only a tool for communication but for learning. In this study, we used the Android platform to design and build a simple language app which is then implemented and tested. It is then released for distribution subsequently for users to download. The evaluation will be based on the user’s feedback and reviews after they used the app. Positive results were expected and were also achieved. Many users are interested in these mobile applications and are requesting more features to be added. This is taken as further consideration and will be another extended project to improve future mobile learning in the Pacific.