Thursday, November 05, 2015

Technology for Election-related Polling

There is some statistics behind the design of exit polls; but the state of the art is rather poor. Exit polls are giving contradictory predictions about the outcome of Bihar polls, 2015. They failed to predict the landslide in favour of the Aam Aadmi Party in the Delhi elections earlier.
I will offer a suggestion here for a new way of conducting exit polls. Any market research organization could easily try them out. My hope is that small experiments by students learning software technology or management would lead the way and lead to publishable R & D.

The basic premise is that a high percentage of voters have a cell phone. This is not entirely true, but we will return to that question later. Assume that the polling organization (call it pollster) offers during a national election handsome prizes like a hundred airline tickets to a holiday destination, a thousand gift coupons, and ten thousand brand-name pens. To qualify for a prize, you need to send an SMS within five hours of a poll closing, from the constituency concerned, using a cell phone registered in that constituency, giving the constituency name and the party you predict will win there. The polling computer will allow each cell phone to cast only one vote. Now comes the second premise: that you will most likely predict that the party you voted for will win. We assume that you did not waste your vote for a party you expected to lose. You reflect your own belief as well as those of the people who influence you by their conversations. We assume that political parties will not waste much effort in falsifying an exit poll as that confers no real benefits on them.

That is the basic idea. What would be cost-effectiveness of the idea, how can it be improved, can it be modified to serve other information collecting functions, etc., are good questions for students (and others) to examine. We also need to examine privacy issues involved and whether cell phone companies analyze the text messages they carry.

I would like to add another idea, to encourage voters to participate in the exit polls. The computer could randomly select a specified small fraction of the participants within a few minutes of receiving their text messages and send them a message like this: “You have been selected to receive a ----- if the party you have indicated wins in the constituency you have named. Prize winners are selected by a computer which uses random numbers to make fair selections”. This will increase the confidence of the participants that fair practices are in use.  

Finally, a word on my basic premise. Will the people at the bottom of the socio-economic pyramid really have proper representation in a technology-based poll? No. This is a matter worth considering.  

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Wednesday, November 04, 2015

Using solar power through an UPS

(This is a small project, but one that should be carried out with responsibility. Do the work only under the supervision of Electrical Engg Department Staff in your college/university Lab).
  
Solar panel prices are coming down but if you include the cost of batteries and solar panels, they are expensive. Products are available in India from a few vendors, but they are not priced like commodity items.  On the other hand, common UPS units are available at commodity prices. They incorporate a battery and inverter and come with power cables, plugs & sockets, all ready for use. The project suggested here is one of connecting a solar panel (SP) providing about twenty or thirty watts of power for a few hours a day to an UPS of the type used with a PC. The schematic below illustrates the idea.


 


A solar panel with a nominal rating of 30 W seems ideal for charging a UPS of the type discussed above.
The SP needs only to provide a DC output at the voltage of the UPS battery, which is usually 12 V.  The charge controller has to prevent reverse flow of current and prevent over-charging.  The typical UPS used with PCs has a 600 VA rating and has capacity of about seven Ampere hours (Ah). That provides for a nominal 84 Watt hour (Wh) energy storage. Assuming that we do not want to utilize more than 50% of the nominal capacity before recharging, such a device can deliver 40 Wh per day, enough to power a 5W LED lamp for 6 hours a day and to provide a few Watt hours to charge one or two cell phones. In fact, some UPS vendors offer models with built-in USB sockets that will charge most cell phones. 

The Solar Panel
Those interested in understanding sizing calculations would find the website http://www.batterystuff.com/  quite useful.  The site http://www.wholesalesolar.com/solar-information/charge-controller-article gives some information on the working of a charge controller. ICs for use in building a charge controller are available from vendors such as Texas Instruments.  I would urge students interested in this project to read about the risks of continuing to draw current from a battery when its voltage has fallen below a specified safe level, such as 11.6 V in case of 12 V batteries. Precautions should be taken to avoid under-voltage operation. One way of ensuring this is to build the system around an UPS that provides protection against under-voltage operation.

Social and Economic implications
The LED revolution has made small size solar installations attractive. Five hours lighting per day through a 5 W LED and a cell phone charger working round the clock would be a boon to most rural households. A solar UPS can provide this even without traditional electrification, but benefits from it if available. It makes it easier to live with power-cuts. Lighting based on a solar UPS confers significant advantages to small shops. Remote locations can use solar UPS units to provide some street lighting. Rural hospitals would find reliable lighting very valuable.  This article has had a focus on systems providing power in the range of 5 to 10 W; however, the future will see surging demand for units with higher capacities. At a macro-level, the UPS market in India is already worth several thousand crores of rupees per year; but it largely serves urban customers. Hybrid UPS units that can use traditional electrical supply as well as solar energy are practically absent in rural areas. The technology for putting them together exists and is relatively easy to master. This segment alone is likely to grow into a few thousand crores per year business within a few years. In the early stages, pioneering engineers will put together their own products and provide services. Within a few years, we can expect that small hybrid units will roll off big production lines and be available at commodity prices. The pioneers will see their business continuing to grow despite such mass manufacture, as long as they are present in rural locations to handle retail sales and to provide services.
Apart from providing reliable lighting, this industry will create several hundred thousand jobs all over the country.

Srinivasan Ramani