Tsuneo Tsukatani

Operation of storage reservoir for water quality by using optimization and artificial intelligence techniques

Water quantity and quality are considered to be the main driving forces of the reservoir operation. Barra Bonita reservoir, located in the southeast region of Brazil, is chosen as the case study for the application of the proposed methodology. Herein, optimization and artificial intelligence (AI) techniques are applied in the simulation and operation of the reservoir. A fuzzy stochastic dynamic programming model (FSDP) is developed for calculating the optimal operation procedures. Optimization is applied to achieve multiple fuzzy objectives. Markov chain technique is applied to handle the stochastic characteristics of river flow. Water quality analysis is carried out using an artificial neural network model. Organic matter and nutrient loads are modeled as a function of river discharge through the application of a fuzzy regression model based on fuzzy performance functions. The obtained results show that the proposed methodology provides an effective and useful tool for reservoir operation.

Simplified Pearson distributions applied to air pollutant concentration

Abstract Determination of Pearson system of distribution is proposed by using first three moments of the data. The actual distribution of air pollutant concentration observed at two typical areas is well approximated by Type VI distribution (Beta distribution of the second kind). About half of the data observed around an isolated source show convex curve when the cumulative frequencies are drawn on the probability paper of log-normal distribution which belongs to Type VI of Pearson system. Errors of the distributions are evaluated between log-normal and Type VI of Pearson system.

Statistical model of air pollutant concentration and its application to the air quality standards

Abstract A statistical model of the time series which gives the relations between air pollutant concentration, averaging time and frequency of occurrence is described. The percentile concentration with respect to averaging time is expressed by two functions. One of them is the probability density function, which is approximated by the log-normal distribution and the other one is the spectrum density function, approximated by the Markoffian spectrum. The authors suggest the mathematical application of the model to the air quality standard for sulfur oxides in Japan, and two important problems involved in the standard are discussed.

A demineralization mechanism for Lake Balkhash

Lake Balkhash is one of the many closed lakes in Central Asia. Mechanisms of demineralization in Lake Balkhash were considered from results of surveys undertaken on the lake and along the Ili River. Electrical conductivity (EC) values at the eastern coast in south-western Lake Balkhash were higher than those of the western coast. The Ili River enters at the south-western corner of the lake, so that EC values of this area are low. This water flows westwards. The distribution of Ca2+ concentrations showed that these were lower value in Lake Balkhash than along the Ili River, implying Ca2+ removal by the lake. Amongst suspended mineral matter in the lake occur calcite and dolomite. Thus, a possible mechanism of calcium removal is that it is removed as crystals of calcite or dolomite. SO42− concentration within the lake has increased for the past 37 years. This may be caused by the discharge into the lake from the city of Balkhash of waste water from a copper smelter.