Examining the effectiveness of rainwater collection systems in a Nigerian leper colony using the behavioural model

Olaoye Rebecca A., Coker Akinwale O., Sridhar Mynepalli K. and Adewole Esan M.

Rainwater from roof catchments can be a valuable source of water and can be quite safe to drink when stored in a properly installed and well maintained water storage system. It is noteworthy to observe the capacity intended for rainwater storage because this factor is a determinant to both its initial cost of construction and its effectiveness, especially during the dry season for the isolated lepers who are sited outskirts of towns and cities where the water mains does not get to. This paper examines the effectiveness of rainwater collection systems in a Nigerian leper colony using behavioral method, such that the relationship between the storage and the utility or demand was punctuated in terms of water saving efficiency. The data obtained were used to mathematically simulate the model algorithms using the time interval of an hour, a day and a month. The detailed analysis for the application of these time interval models were expressed in a dimensionless ratio known as the storage fraction, S/AR, where S= storage capacity (m³), A= roof area (m²), and R= average annual rainfall (m). The values obtained for the water saving efficiency using the YAS and the YBS algorithms shows that the YBS gives an exaggerated value for the data plots while the YAS operating algorithm showed a conservative estimate and could be used as a standard of comparison and calibration for other models. The hourly models can therefore be most effective for relatively small stores with storage fractions less than 0.014. Daily models can be used more effectively for stores with storage factions above 0.014 while the monthly time model for store capacities with storage fractions greater than 0.13.

Modeling inland valley suitability for rice cultivation

Masoud J., Agyare W. A., Forkuor G., Namara R. and Ofori E.

The demand for rice (Oryza sativa) in Ghana is increasing at a rate of 11.8% from 939, 920 t in 2010. Though there has been some increase in production it does not match the increase in consumption. This study seeks to determine the most suitable areas for inland valley rice cultivation using computer based models for selected sites (15km by 15km) in the Brong Ahafo Region (BAR) and Western Region (WR) of Ghana. A sensitivity analysis was carried out by excluding the least contributing parameters and varying their weights to determine highly suitable areas. Finally, 12 most sensitive input parameters were identified from the original 22. These were used to model for five suitability classes (highly suitable, suitable, moderately suitable, marginally suitable and not suitable). The model results based on parameters having equal weights showed that 0.5% and 11.8% (BAR); and 1.4% and 21.4% (WR) of the area were highly suitable and suitable respectively. Using unequal weights, 0.8% and 7.6% (BAR); and 0.9% and 13.6% (WR) of the area were highly suitable and suitable respectively. The study successfully mapped out suitable areas for rice cultivation using spatial models based on limited data set, which can be adopted for use elsewhere.

Distributed arithmetic based butterfly element for FFT processor in 45nm technology

P. Augusta Sophy, R. Srinivasan and J. Raja

Fast Fourier Transform (FFT) is one of the important signal processing algorithms because of its applications in digital filtering, communication, image processing, spectral analysis and estimation etc. Butterfly computation is the basic operation in the FFT algorithm. In this work, a novel approach is thought of and used in implementing the butterfly element. Distributed Arithmetic Algorithm (DAA) is used to do the butterfly computation instead of using conventional multipliers and adders. This has resulted in a more efficient butterfly element both in terms of area and power. This paper describes the design of such an area efficient butterfly module. Single precision floating point representation is used for the data. This design leads to a lot of area saving and also power saving. This butterfly can be used as the basic building block of a low power reconfigurable FFT processor. This finds its application in OFDM and there by in software defined radios.

Performance efficient heterogeneous multi core scheduling strategy based on genetic algorithm

A.S. Radhamani and E. Baburaj

Multi-core processors offer a significant performance increase over single core processors. Therefore, they have the potential to enable computation-intensive real-time applications with stringent timing constraints that cannot be met on traditional single-core processors. However, with the number of cores on a single chip continuing to increase, it has been a great challenge to effectively manage the energy efficiency of multicore based systems. Power and temperature management are also two concerns that can increase exponentially with the addition of multiple cores. Design innovations in multicore processor architectures bring new optimization opportunities and challenges in the computing era. System performance will be further enhanced by addressing these challenges. In particular, the process (task) scheduler is one of the critical challenge is garnering great interest. High performance in a heterogeneous multicore system is essential which is achieved by effective scheduling, which remains a challenging problem. Further multi core technology opens research opportunities for energy reduction through efficient scheduling. There may be different hardware and software solutions for the above issue; hardware solutions are based on adjusting dynamic voltage per core, alternatively software approach includes, scheduling task among cores, in heterogeneous environment. Task scheduling in multicore architecture is an extremely difficult problem, because it requires a large combinatorial search space and also precedence constraints between the processes; for the effective utilization of multi core processor system, efficient assignment and scheduling of jobs is more important. Many of the existing algorithms are not focused on task scheduling and core utilization in heterogeneous multi core systems. This paper formulates task scheduling as an optimization problem and the results are compared with the earlier faster scheduler in use. Findings show that, in addition to its optimum solution for large scale problem, the Genetic Algorithm (GA) proposed here fits the heterogeneous multi core parallel scheduling problem of minimizing the completion time as well as in effective core utilization.

Abstract:

At signalised intersection phasing is a multiple arm movements whereas staging is a single arm movement of vehicles at the onset of inter-green light. The purpose of the paper is to determine the extent to which highway traffic directional ratio can be accountable for the effectiveness of signal timing. Phasing and staging would be treated as mutual exclusive movements under varying directional traffic loading. Based on the hypothesis that percentage of directional split would influence traffic signal optimum performance and associated delays, directional split impact studies were carried out in Skudai town, Johor, Malaysia. Major roadway delays for traffic flows with 20/80; 30/70; 40/60; 50/50 incremental directional ratio were analysed. Results show that phasing signal settings are best suited to 40/60 and 50/50 directional flow and staging for 20/80 and 30/70 directional traffic flow. The paper concluded that optimised signal setting based on phasing would be more effective in circumstances where the likelihood of 50/50 and 40/60 directional split are more likely. The same cannot be said of 70/30 or 80/20 directional split.

Calibration and validation of hec-hms model for a river basin in eastern India

D. Roy, S. Begam, S. Ghosh and S. Jana

Abstract:

Assessment of impact of climate change on water resources in river basin requires a proper estimation of availability of water and that can only be achieved by hydrological modeling of the basin. However, hydrological modeling is a complex task and hydrologic models should be well calibrated to increase user confidence in its predictive ability which makes the application of the model effective. In this study a catchment simulation model viz., Hydrologic Modeling System, developed by the Hydrologic Engineering Center, USA (HEC-HMS) (with soil moisture accounting algorithm -- SMA) has been calibrated and validated for Subarnarekha river basin in Eastern India for prediction of its hydrologic response. The analysis shows that the soil storage, tension zone storage and groundwater 1 storage coefficient to be the sensitive parameters for the simulated stream flow. The Nash - Sutcliffe model efficiency criterion, percentage error in volume, the percentage error in peak, and net difference of observed and simulated time to peak, which were used for performance evaluation, have been found to range from (0.72 to 0.84), (4.39 - 19.47%), (1.9 - 19%) and (0 to1day) respectively, indicating a good performance of the model for simulation of stream flow and thereby quantification of available water. The study also demonstrates that the use of semi annual parameter sets that account for changing hydrologic conditions improves model performance. Thus the model may be applied to other watersheds in the Subarnarekha river basin and other hydro -meteorologically similar river basins.

Accelerated properties of steel fibre reinforced concrete containing finer sand

V. M. Sounthararajan and A. Sivakumar

The present study focuses of the influence of waste foundry sand for producing the accelerated rate of hardening at early ages with steel fibre mixed concrete. Experimental tests were conducted on the concrete mixtures containing different percentage of foundry sand (0, 10, 20 and 30%) and the performances were compared with normal concrete obtained from the source directly. The test results indicated that with higher replacement level upto 20 % foundry sand showed an increased cube and cylinder compressive strength (44.2 and 33.1 MPa) respectively at 7 days compared to Ordinary River sand at 28 days compressive strength of concrete. It can be also noted that the various waste foundry sand concrete mixes containing different mix constituents showed a consistent strength increase compared to controlled concrete. From the experimental results it is suggested that, waste foundry sand can be effectively utilized for producing high early strength concrete without affecting the durability properties. However, the replacement level of waste foundry sand can be restricted upto 30%, since it will affect the hardened and durability properties of concrete.

Abstract:

Generally software systems are scantily documented and incomplete specifications in the documents results in high maintenance cost. To lower maintenance efforts, automated tools are necessary to aid software developers to understand their existing code base by extracting specifications from the software. Specification mining aids the document to intend software behaviour, software maintenance, refactor or add new features to software, and detecting software bugs. In this paper a new technique to called CT Trace Miner is proposed to efficiently mine software specifications, which in turn mines software specifications from program execution traces. Then the mined specification using the CT Trace Miner approach is given as input to the ANOVA Two Way feature selection approach for selecting the best features. Conclusively, ARC-BC classifier is used to categorize the selected features. The experimental results exposed that the proposed approach provides better results than the existing approach.

Selective estimations of empirical roadway capacity

Johnnie Ben-Edigbe, Hashim Alhassan and Suleiman Aminu

Abstract:

Traffic theory is concerned with the movement of discrete objects in real time over a finite network in 2 Dimensions. It is compatible with or dependent on fundamental diagram of traffic. Without question traffic flow is an essential quantitative parameter that is used in planning, designs and roadway improvements. Road capacity is significant because it’s an important indicator of road performance and can point road managers in the right road maintenance and traffic management direction. In this paper four direct empirical capacity measurement methods have been considered. To test the efficacy of each method data for peak period, off-peak and transition to peak have been used. The headway and the volumes methods lack predictive capability and are suitable only for current assessment of flow rates. The product limit method is weak in its predictive capability in view of the arbitrariness in the selection of the capacity value. It is also an extreme value method; hence not all volume data can be used with this method. The fundamental diagram method has good predictive capability and furnishes capacity values consistent with the standard of the facility. Unlike other methods, it does not rely on bottleneck conditions to deliver the capacity value. The paper concluded that each method is uniquely suited to prevailing conditions and can be so employed.

Drying shrinkage properties of accelerated flyash cement concrete reinforced with hooked steel fibres

V. M. Sounthararajan and A. Sivakumar

Abstract:

Shrinkage of concrete during the process of drying is a inherent property which is accompanied with volume reduction and typically a very serious problem for mass concreting works. This volumetric reduction of concrete needs to be addressed at the outset since any restrained dimensional changes leads to cracking. The present study focuses on the influence of concrete with accelerated strength properties and the effect of steel fibres on the overall shrinkage characteristics of concrete. The effect of shrinkage was studied for the various design concrete mixtures containing different percentage of flyash (20 and 40%); steel fibres (0.5 and 1%) and accelerator (1%, 2% and 3%) and the performances were compared with plain concrete. The test results showed that for concretes containing 20 % flyash replacement, 1% steel fibre and a 1% accelerator dosage showed a consistent reduction in the drying shrinkage value (174 micro strains) compared to plain concrete tested at 28 days. It can also be noted that the drying shrinkage value was found to be lower in the case of fibre concretes compared to controlled concrete. However, the concretes with accelerator showed higher drying shrinkage compared to controlled concrete due to increased rate of hardening. From the experimental results it is suggested that, low calcium flyash, steel fibres and accelerator can be effectively utilized for producing high early strength concrete without showing any appreciable volume reduction.