Optimization of Multireservoir Systems by Genetic Algorithm

Application of optimization techniques for determining the optimal operating policy of reservoirs is a major issue in water resources planning and management. As an optimization Genetic Algorithm, ruled by evolution techniques, have become popular in diversified fields of science. The main aim of this study is to explore the efficiency and effectiveness of genetic algorithm in optimization of multi-reservoirs. A computer code has been constructed for this purpose and verified by means of a reference problem with a known global optimum. Three reservoirs in the Colorado River Storage Project were optimized for maximization of energy production. Besides, a real-time approach utilizing a blend of online and a posteriori data was proposed. The results obtained were compared to the real operational data and genetic algorithm was found to be effective and can be utilized as an alternative technique to other traditional optimization techniques.     

Assessing Flood Induced Land-Cover Changes Using Remote Sensing and Fuzzy Approach in Eastern Gujarat (India)

Natural hazards such as flooding can cause changes in land-cover. The present study deals with the changes in land-cover in three worst affected districts (Anand, Vadodara and Kheda) of Gujarat state in India due to severe flood during 2005. The Indian Remote Sensing (IRS) P6 Linear Imaging Self Scanning (LISS) III satellite imageries of pre- and post-flooding periods were used as sources of information for the study area. Three classification approaches (unsupervised ISODATA, supervised Maximum Likelihood Classifier, and fuzzy rule based) were used to extract flood induced land-cover information. Results obtained from the above classification approaches were compared. Soft computing technique such as fuzzy based image classification gave better separability amongst classes as compared to hard classification techniques. The accuracy assessment showed that the fuzzy approach can predict land-cover more accurately than traditional approach and also showed great potential for dealing with mapping of flood induced land-cover. Unsupervised classification results for the period October 2004 to October 2005 revealed decrease in inland water bodies (14.49%) and agricultural area (6.42%) while increase in remaining land-cover. During February 2005 to February 2006, all land-cover classes decreased except agricultural fallow and sparse vegetation. In case of supervised classification, decreasing trend was observed only in case of agricultural area (6.78%) during October 2004 to October 2005. Similarly, during February 2005 to February 2006, increase in coastal water bodies (0.73%) and sparse vegetation (1.7%) was observed where as decreasing trend was noticed in the remaining land-cover classes. In fuzzy based classification, only decrease in agricultural area (7.09%) was observed from October 2004 to October 2005, whereas during February 2005 to February 2006, decrease in area was exhibited in all land-cover classes except coastal water bodies and sparse vegetation. Change detection indicated interchange of areas between inland and coastal water bodies and decrease in agricultural area leading to increase in area of agricultural fallow and sparse vegetation.     

A GIS Framework for Changing Cropping Pattern Under Different Climate Conditions and Irrigation Availability Scenarios

Irrigation water availability is a main driver which determines cropping patterns for an irrigation area. Irrigation water availability will potentially reduce due to changes in climate and irrigation extraction limits. Cropping patterns should be adjusted to meet this challenge. This study presents a new approach for assessing future cropping patterns using GIS in combination with an Irrigation Water Availability Simulation model (IWAS) at irrigation area scale. The IWAS-GIS framework was developed for analysis of cropping pattern options based on the forecast of irrigation water availability in 2030 for the Murrumbidgee Irrigation Area (MIA) which is one of the most important irrigation areas in Australia. Six scenarios considering climatic conditions and the irrigation availabilities were input into the IWAS-GIS framework to simulate cropping pattern changes corresponding to predicted monthly irrigation water availability. Cropping patterns were designed by integration of soil type and irrigation water availability to improve irrigation sustainability. Simulations results indicate that the total irrigated areas will likely decrease with drier climate and less irrigation availability. Rice and pasture areas change significantly when climate and irrigation availability varies. Under the same climate condition, horticulture area increases when irrigation availability decrease. The percentage of lands which are unsuitable for cropping has reduced with the drying climate and shrinking irrigation availability. The IWAS-GIS is simple to implement and provides an easy way for assessing spatial cropping pattern changes based on irrigation water availability. This framework was developed to help irrigators plan cropping patterns corresponding to irrigation water availability. It is flexible to be adopted for similar applications in other irrigation areas.     

Water Concession Principles for Geothermal Aquifers in the Mura-Zala Basin,NE Slovenia

Demand for thermal water in the Mura-Zala basin, situated between Slovenia, Austria, Hungary and Croatia, is constantly increasing, with the sandy geothermal aquifer within the Neogene Mura formation being the most exploited. During the water concession granting process various problems were identified, together with the need for elaboration of the uniform concession granting principles. The latter were devised according to the specific hydrogeological settings and field inspection of 23 geothermal wells, performed through use of an adapted methodology. The inspection revealed changes in wells performance, low efficiency of energy abstraction and a lack of reinjection. The acquired information was applied to the development of particular principles, including the six key indicators. Firstly, a unified and integrated operational monitoring programme must be established, and upgraded by a national surveillance monitoring. Secondly, an application of the best available techniques is proposed. Stimulation of energetic and balneology efficiency is also needed, with recharge and reinjection conditions evaluated and applied where possible. Limited or full water concessions could be granted based on their fulfilment then. This continuous step-by-step approach should enable the implementation of adequate measures to meet the standards required for the thermal groundwater bodies according to the EU water framework directions.     

Dielectric properties of iron doped calcium copper titanate,CaCu<Subscript>3</Subscript>Ti<Subscript>3.9</Subscript>Fe<Subscript>0.1</Subscript>O<Subscript>12</Subscript> ceramic

Dielectric properties of iron doped CaCu₃Ti₄O₁₂ (CCTO), viz. CaCu₃Ti_3.9Fe_0.1O₁₂ (CCTFO) prepared by a novel semi-wet route have been investigated. X-ray diffraction of powder sintered at 900 °C show formation of single phase solid solution. Energy dispersive X-ray spectroscopy (EDX) confirmed the presence of CuO rich phase at grain boundaries of CCTFO. Nature of dielectric relaxation observed above room temperature is studied using complex plane impedance analysis and modulus spectroscopy. It has been found that out of the two relaxations reported earlier above room temperature, one occurring at lower temperature is due to grainboundaries interfacial polarization.     

Innovative methodologies of circuit edit by focused ion beam (FIB) on wafer-level chip-scale-package (WLCSP) devices

As packaging technology advances to wafer level chip scale packaging (WLCSP) to enable reduced chip size and manufacturing cost, circuit edit has become a critical issue for the fully packaged integrated circuits (ICs). These advanced package types cannot be rebuilt on a single chip; therefore, function testing after circuit edit of WLCSP faces challenges. Furthermore, there are routings at the redistribution layer of WLCSP ICs. Circuit edit was applied on both the chip and the package level. In this paper the focused ion beam was applied to mill the organic material of the package structure to expose underlying ICs, instead of chemically destroying the packaging. Metal line cutting and conductive path deposition were also developed by a beam-based technique. These new approaches make the direct edit of electrical circuitry possible not only in ICs but also at package level. Therefore, for the debug process and for failure analysis, the WLCSP ICs have negligible damage and negligible signal integrity loss by retaining the original packaging structure.     

LA ICP-MS in microelectronics failure analysis

To keep up with the trend of integrating more functionality within lighter and smaller consumer electronics devices, the dimensions of components keep shrinking. Technologies such as high density interconnection, 3-D interconnection, system in package (SIP), and flexible circuit are becoming more commonly used. The smaller dimensions of the conductors and insulators (spacing) used in these technologies make them more sensitive to chemical contamination. Trace amounts of chemical contamination introduced during the manufacturing process or in the field can cause device failures. The failure mechanisms include inversion-induced leakage current, corrosion, and electro-chemical migration, to name a few. The complexity of materials used in a highly integrated system also poses new challenges for fault isolation and chemical characterization in failure analysis. This paper calls attention to the selection of appropriate analytical techniques in terms of spatial resolution and sensitivity, sample preparation complexity, throughput, and detection limitations. We present two failure analysis cases in which LA-ICP MS, in conjunction with other analytical techniques, was successfully used to identify the source of chemical contamination and the root cause.