Shahriar Khan

An energy saving program for bangladesh, for reducing load shedding, and for continuity of power for IT sector

The success of computers, IT, and telecommunications hinges greatly on the inexpensive and uninterrupted availability of power. Even with the gradual depletion of fossil fuel, and the rise in fuel prices, there has been insufficient effort towards saving electricity and making the most of remaining fuel reserves. It is time to adopt energy saving programs in Bangladesh, creating awareness that extravagant consumption is detrimental to national, global, and long-term interests. Such energy saving programs have been implemented to various extents in countries like Brazil, Norway, New Zealand, and the USA. With its high population density, low development, poor economic infrastructure, and dynamic river network, Bangladesh provides a unique backdrop to an Energy Saving programs. Such a program should reduce load-shedding, distribute electricity among more users, and divert electricity to productive uses like irrigating fields and preventing manufacturing stoppage. Continuity of electricity would also save our huge investment in generators and UPS equipment. An energy saving program should be well-understood and researched by policymakers and experts. An important part of such a program should be changing consumer behavior, such as turning off appliances when not in use. Power-hungry air-coolers develop acclimatization and dependence in users, who then perceive normal outside temperatures as uncomfortable. Low-power alternatives to air-coolers are ceiling fans and ventilator fans on walls. LED lights, compact fluorescent lamps, and IT and telecommunications are to be promoted as efficient uses of electricity. Urban sprawl to distant suburbs should be contained in favor of compact townships, which are better adapted to buses. Buses should be promoted over smaller cars, which should be promoted over larger hungry cars and SUVs. This paper pursues such common sense approaches, together with recommendations by experts, and implementation by policymakers.

Analysis of incipient behaviour of multiple distribution insulators

This paper presents research characterizing the leakage (incipient behaviour) of single and multiple distribution insulators through staged experiments. Four sets of field experiments were conducted over a two year period in which single and multiple insulators were artificially contaminated and energized on a lateral of a distribution system. More than 70 recordings were obtained from monitoring at the site of the insulator(s) under study and at the substation feeding the lateral. This paper focuses on the characterization of the site recordings. Individual insulator leakage currents showed an erratic behaviour with bursts lasting from half a cycle to several seconds. The multiple insulators conveyed a cumulative behaviour caused by individual insulators in various stages of leakage. The results are characterized graphically in the time and frequency domains.

Automated versus human traffic control for Dhaka and cities of developing nations

Traffic control is a rapidly evolving subject, reflective of new developments in electrical sensor technology, and information and communication technology. In Dhaka, a city of about 12 million people, traffic congestion has worsened dramatically over the last 2-3 years, in spite of the introduction of automated traffic lights. Expensive and drastic measures, such as the construction of flyovers, have been implemented to counter traffic congestion. Although various studies have been conducted on this topic, few or none have identified the many advantages of human traffic control. Dhaka and other cities of developing nations, present traffic situations quite unlike that of developed countries. As a result of improper planning and land management, only about 7 % of the city area consists of road space (compared to about 12% of New Delhi, or 20 % required ideally). In 2004, human traffic control started getting replaced with a modern signaling system, with the good intent of bringing discipline in traffic. In spite of optimistic predictions, it was seen that traffic congestion had become much worse. In the field of information and communication technology, the advantages of human decision-making over automated or microprocessor-based decision making is well recognized. It is proposed and shown here that for Dhaka, human traffic control is a better alternative than automated traffic lights. Human traffic control is preferred for Dhaka, and other developing nations, because of the relatively fewer cars, the few major intersections, and the low cost of human traffic-controllers. As signaling intervals are determined by past measurements of traffic, automated traffic control cannot take into account statistical and event-related variations of traffic. A human traffic controller makes the better decision of allowing through a long line of cars, avoiding the transition times during predetermined changing of signals. He/she does not show green to an empty street with cars waiting in another line. The neural-networks of a traffic controller can assess traffic in visual range, and take intelligent and adaptive decisions. Even with the best road sensor technology, accompanied by telecommunication and fast microprocessors, it is a formidable task for an automated traffic system to match the decision-making capacity of a human traffic controller.

Graphically including gain K into conventional root locus

The root locus method in control systems shows damping a and natural frequency w, but somewhat surprisingly, does not include graphically the gain K. This paper proposes the natural continuation of root locus, that K be shown graphically with the s-plane. To illustrate the principle, graphs were drawn with Matlab for transfer functions ranging from first order to second order with multiple zeros. Far from the simple curves of the conventional root locus, a wide range of complex curves and artistic shapes were observed. The three dimensional plot of the real K axis with the complex s plane raises some fundamental mathematical questions. How much is the validity and usefulness of real axis perpendicular to a complex plane. The graphical incorporation of K into the root locus has become easier than ever with the availability of softwares such as Matlab.

Warning sounds and color for reducing bird and bat mortality at wind turbines

The large number of bird and bat fatalities by wind turbines has slowed the installation of new turbines, and even prompted the dismantling of turbines with high casualty records. The sights and sounds of turbines, while considered an infringement on the environment, are seldom recognized as a visual and auditory warnings to birds and bats. Declining bird casualties in successive years implies a learning process in the birds where the view and noise of turbines have taught remaining birds and bats to stay away. This paper discusses providing additional auditory and visual stimuli that will further catch the attention of the birds, helping associate the sights and sounds with mortal danger. Sounds such as screeching and gunshots are recommended, based on what would be disturbing and repelling to birds and bats, and not much audible beyond the immediate vicinity of the turbine. Different sounds may be generated for different species, such as ultrasonic sounds for bats. Ultra-violet patterns painted on the blades may catch the visual attention of the birds, without being too obstrusive to human vision. Warning visual patterns and bird-repelling sounds should be similar for turbines, so that birds do not have to re-learn the warnings for different turbines. As birds are globally mobile, there can even be convergence towards a common world standard for warning colors and bird-repelling sounds.

Convergence in spelling, and spell-checker for Romanized Bangla in computers and mobile phones

Methods for Romanizing Bangla, or writing Bangla with the English alphabet were proposed half a century ago, but never gained popularity. Today, a new type of Romanized Bangla has emerged in mobile phone SMS, email, chatrooms, social networking websites, etc. Mobile phone SMS are widely used by individual users, phone operators, advertisers, the government, etc. In this study, about 500 - 1500 high-impact Romanized Bangla messages sent to wide audiences over about 4 years, were studied. In 2011 about 50% of Romanized Bangla words had converged to common and uniform spellings. In this study, the convergence to uniform spellings was seen to have increased to about 75 % of the words. Extrapolating from these trends, over the next three years, the convergence may rise to 85-90 % of words. Romanized spellings were found to be brief, for ease of typing with hand-held devices. English words were being rapidly absorbed into the Bangla language. As spellings converge further towards uniformity in the next few years. Romanized Bangla will become even easier to read and write, The common spellings also make it easier for computer softwares to recognize and convert Romanized Bangla to Bangla script. While it may not be possible or advisable to alter the convergence in the spelling trends, it may be possible to exert some force on the convergence with a spellchecker. Favorable spelling trends would make the Romanization consistent with pronunciations in English, making Bangla language more readily accessible by speakers of English.

The divided flash memory device for implementing neurons and neural networks

Neural networks have been of interest for long, but have been hard to implement in practice, because of excessive complexity and training required. Neural networks have been proposed with hardware, such as with FPGAs and VLSI. This paper proposes implementing neurons and neural networks with MOS Flash memory technology. The floating gate of the flash memory can store a charge for years, influencing the conductivity of the channel. It is proposed that the gates be divided into a number of control gate-floating gate pairs. Each gate pair will behave mostly independently, with the charged floating gate acting as a weighting on the input. The multiple floating and control gates may replicate the weighting and summation of inputs to dendrons, and their output to an axon. The voltage of the floating gate may be the “training” required in neural networks, and may be set by a method such as backpropagation. The resulting conductivity of the channel will be a non-linear combination of the inputs, very similar to the functioning of a neuron. The proposed devices may be placed in parallel for a different set of behaviors. The non-linearities of the divided Flash memory will have similarities and differences with the nonlinearities of a neuron. The non-linearities of the divided Flash memory may be manipulated through design to give optimized results for a neural network. Billions of divided Flash memory devices, and artificial neurons may be implemented in a single chip.

Automated digital archive for land registration and records

Land management is an important issue for Bangladesh, where the land registration process is a major barrier to the economic growth of the country. Technology and IT can greatly facilitate the creation of a proper land management system. This paper focuses on various issues and problems related to the current system of land management. It offers an alternative management system using IT features and shows a comparison between the existing system and the proposed system. It is shown that a digitized land management system in Bangladesh can bring positive outcomes in the entire process by minimizing hassle, expenditure, time, and staff dishonesty.

Largest blackouts around the world: Trends and data analyses

Blackouts are among the last remaining major challenges in power systems. In this paper, publicly available data have been compiled into a dataset of large-scale blackouts that happened from 1965 to 2015. A formula has been devised to filter the largest blackouts by equally weighting the number of people affected and the total restoration. Analysis is then performed on the selected data points in order to find trends and patterns. This paper also explores the different causes that trigger initial disturbances in the power system; some of which eventually leads to a cascading effect and cause widespread power failures. Finally, region-wise risk analysis of different causes of large-scale blackouts as well as fault analysis have been performed

Enhanced audio-visual warnings for reducing bird fatalities at wind turbines

Bird and bat fatalities by wind turbines has slowed the installation of new turbines, and even prompted the dismantling of existing turbines. Other animals can coexist in artificially created dangerous environments, like dogs maneuvering among cars in busy streets. Based on this concept, a previous paper has proposed that bird and bat mortality can be reduced by audio visual warnings in the proximity of wind turbines. This paper proposes further details of audio visual warnings, including directional lights, which will enhance the learning process and act as warnings. The leading edges and the peripheral regions of the blades are most likely to strike birds and bats, which may be trained to keep away by the colors, lighting and sounds of leading edges. Lights and sounds need only have a range of a few tens of meters and directionality towards the danger zone, meaning the lights and sounds will be imperceptible to humans in the vicinity. So that the globally mobile birds do not have to relearn the warning signals, countries can converge towards common standards for the warning colors, lights and sounds on wind turbines.