Saturday, February 28, 2009

Fundamentals of Software Testing

I recently read a Book, Software testing (Second Edition) by Ron Patton from SAMS Publications. Few concepts in this book enlightened me the complexity involved in Software testing.

From the points I learned out of this book is, I can see a pattern regarding the spectrum of skills and knowledge of people who participate in the practice. In the past, it was not uncommon for some companies to hire ‘clever’ people who were simply good at finding bugs into testing roles. I suspect that some people thought as long as they were finding behavioral type issues of the software they were providing a benefit to the company because they were ‘good at representing the customer.’ At the other end of the spectrum the developer’s in testing roles who failed to realize the challenges in software testing. In both extremes complacency and stagnation usually occurs. Of course, there are many other Software testers between these extremes; some who will go on to become professional Software testers and have significant impact, and others who will simply belly-ache and whine about how unfair it is or claim how wrong any change is and why change won’t work.

As professional software Engineers we must constantly strive to improve our knowledge of testing, technology, and the systems we are working on. We must also increase our skills and abilities as the demands of the role expand beyond the traditional comfort zone of behavioral testing and ‘playing customer advocate’ by executing ‘tests’ to find bugs at the end of a cycle. The challenges of testing complex systems built around advancing technologies significantly raises the aptitude bar for Engineers. To drive engineering quality upstream and form closer customer connections is also impacting the role of testing and how testing adds value in the lifecycle . Reinstituting best practices such as design and code reviews and inspections (when warranted), or developing new approaches or tools to help increase testing effectiveness and reduce costs also require greater skills and knowledge among Software testers.

The formidable challenges of testing software that lie ahead will require highly intelligent critical thinkers who also have an in-depth understanding of the systems they are working on, and who possess the technical aptitude to provide valued input in throughout the product cycle. Indeed we work in a very dynamic industry filled with diverse challenges that demand continued learning and greater proficiency of the skills used in our profession.

More Electric Aircrafts

I am writing this post from the studies I am doing these days on Actuator Technologies, part of TSG group for the company I am working with.

For years engineers have dreamed of an all-electric aircraft. They have envisioned a concept called "Fly-by-wire," in which electrical power moves aircraft flight surfaces. Gone would be the complex, heavy, maintenance-intensive, and (in combat) vulnerable hydraulic systems with their flammable liquids operating at high temperature and pressure. Gone, too, would be the miles of tubing, the pumps and valves. Weight could be shifted from plumbing to passengers, fuel or mission payloads.

The transition to an all-electric aircraft is still many years in the future. But aircraft engineers have tested electrohydrostatic actuators (EHAs), which combine electrical and hydraulic power. Hence the evolutionary "more electric aircraft" idea. EHAs are electrically powered but use small hydraulic pumps and reservoirs that transform electrical power into hydraulic power.

To move the huge Primary and Secondary surfaces of the aircraft hydraulically, only, was considered but was discarded in favor of a hydraulic-plus-electric flight control architecture in the past.

The use of electrically powered actuators, however, allows designers to efficiently segregate power distribution channels and save weight. Increased hydraulic pressure in the remaining hydraulic circuits–from 3,000 psi to 5,000 psi–also saves weight. It reduces the size of components, generation equipment, tubing, and the amount of fluid required, and makes installation easier. Overall, the benefits are clear: improved reliability and maintainability; reduced weight and increased cost savings; and increased safety margin because of the use of dissimilar power sources. "Because of the dissimilar [flight control] architecture, if we lose hydraulic power, the aircraft does not lose any flight handling capabilities. "There will be no impact on the performance of the aircraft."

Electrohydrostatic actuation will generate large weight savings. "The combination of the higher hydraulic pressure and the ‘more electric’ flight control architecture led to a weight reduction of approximately [3,307.5 pounds] 1,500 kg for the aircraft. For variable-frequency power generation, "weight was not the driver". That decision "was more oriented to reliability and maintenance cost." "It’s clear that we are oriented more and more toward the ‘more electric aircraft,’" these days.

More to follow soon. Stay Tuned!

MRO for Avionics at Hyd, India

Hello All,
Few of my Blog readers might be wondering what is MRO. It is Maintenance,Repair and Overhaul Centre for the Aircrafts. Aircrafts are very similar to our two and Four wheelers and they need maintenance on certain systems after "n" no. of Flight hours. We dont have this kind of facility in the southern India till date.
GMR Hyderabad Intl Airport Ltd. is Partnering with MAS Aerospace Engineering to set up a 50/50 joint venture that will supply airframe maintenance, repair and overhaul at Rajiv Gandhi Intl Airport (HYD). Starting in the third quarter of 2010, MAS-GMR Aerospace Engineering will provide services such as base maintenance and C-checks for commercial aircraft, including the Airbus A320 and Boeing 737. The joint venture anticipates servicing 60–80 aircraft per year. As per the Forecast, despite the global economic downturn, more than 350 aircrafts are currently operating in the country. “It is expected that more than 200 new aircraft will be headed for India in the next few years, with a possible ten-fold increase of 2,000 new planes in the next 10–15 years. Good going and God Bless Aerospace Business!

Sunday, February 22, 2009

Globalisation and Impact on Individuals

I decided to write the Post on Globalisation and impact on Individual Household after reading the Book "New Systems Competition" by Sinn, Hans-Warner. Somehow I pushed this task aside, as I am busy at work. I really want to share with my readers what economists are thinking about globalisation and its impact from the books I read. But, frankly I am very confused how to start the column on Globalisation and its impact on Individuals.

Today’s globalisation is operating with higher resolution. It is not enough to think of skill groups and sectors; the impact is more unpredictable, sudden and individual than in the past. The current crisis may pose political challenges to both financial development and economic integration. The current global financial crisis highlights the vexed issues of what role national governments should and do play in an internationally integrated economic system. Government policies meant to shelter citizens from risk may indeed be more important in countries where international market access fosters opportunities to trade but also exposes workers to more frequent and intense shocks.

The relationship between global work force is negative as everyone wants to grab the piece of cake available and leading to internal politics. This suggests that as technological progress and multilateral trade liberalisation have made borders less of a barrier to economic activity but introduced lot of politics into the system. As an increasingly globalised economic system increases the risk households face and makes it harder, someone has to pick up the slack. As globalisation progressed, financial development substituted for government policies. Financial markets must indeed be more important if international competition makes it difficult to implement social protection schemes while introducing new sources of income risk.

Globalisation increased aggregate incomes and also allowed aggresive borrowing across the countries to buffer the ups and downs of needs and made it possible to reap the fruits of globalisation in terms of overall competitiveness. But, for individual households, it is not advisable to borrow a lot and go bankrupt upon negative income shocks.

Financial markets are indeed in trouble. To steer clear of the Great recession path we are in now, where redistribution is no longer very effective and financial markets are key to the sustainability of international integration. we must develop an internationally coordinated financial regulation framework and avoid retracing backwards to decayed policies of international integration and financial development.

Saturday, February 14, 2009

Flight crashes and importance of Flight Data and Voice Recorders

I am honored to write this Post on Flight Data and Voice Recorders as I worked on these for two and half years (March, 06 to May, 08). I realised to write this post after the Hudson and Buffalo incidents. These recorders are installed to help reconstruct the events leading to an aircraft accident.

Large commercial aircraft and some smaller commercial, corporate, and private aircraft are required by the FAA to be equipped with two "black boxes" that record information about a flight. One of these, the Cockpit Voice Recorder (CVR), records radio transmissions and sounds in the cockpit, such as the pilot's voices and engine noises. The other, the Flight Data Recorder (FDR), monitors parameters such as altitude, airspeed and heading. The older analog units use one-quarter inch magnetic tape as a storage medium and the newer ones use digital technology and memory chips. Both recorders are installed in the most crash survivable part of the aircraft, usually the tail section.

Each recorder is equipped with an Underwater Locator Beacon (ULB) to assist in locating in the event of an overwater accident. The device called a "pinger", is activated when the recorder is immersed in water. It transmits an acoustical signal on 37.5 KHz that can be detected with a special receiver. The beacon can transmit from depths down to 14,000 feet. Following an accident, both recorders are immediately removed from the accident site and transported to NTSB headquarters in Washington D.C. for processing. Using sophisticated computer and audio equipment, the information stored on the recorders is extracted and translated into an understandable format.

Let me talk in general what Cockpit Voice recorder (CVR) does:
The CVR records the flight crew's voices, as well as other sounds inside the cockpit. The recorder's "cockpit area microphone" is usually located on the overhead instrument panel between the two pilots. Sounds of interest to an investigator could be engine noise, stall warnings, landing gear extension and retraction, and other clicks and pops. From these sounds, parameters such as engine rpm, system failures, speed, and the time at which certain events occur can often be determined. Communications with Air Traffic Control, automated radio weather briefings, and conversation between the pilots and ground or cabin crew are also recorded. More precise timing for critical events can be obtained using sound spectrum software called as FFT- Fast Fourier Transform).

Let me talk in general what Flight Data recorder (FDR) does:
The FDR onboard the aircraft records many different operating conditions of the flight. By regulation, newly manufactured aircraft must monitor at least eighty-eight important parameters such as time, altitude, airspeed, heading, and aircraft attitude. In addition, some FDRs can record the status of more than 1,000 other in-flight characteristics that can aid in the investigation. The items monitored can be anything from flap position to auto-pilot mode or even smoke alarms.
With the data retrieved from the FDR, the Safety Board can generate a computer animated video reconstruction of the flight. The investigator can then visualize the airplane's attitude, instrument readings, power settings and other characteristics of the flight. This animation enables the investigating team to visualize the last moments of the flight before the accident.
They can provide information that may be difficult or impossible to obtain by other means.

Friday, February 13, 2009

Economic Down turn and recession Proof Analysis

After my last post on Valentine's day thoughts, many people enquired me whether something went wrong with me towards relations, or someone hurt me personally. It was just my thoughts, nothing to do with any relations. I am here now, to write on different subject which I am trying to pick up.

Okay, I am here to write post on Economic Down turn's, which I am following very deeply these days as I am the big time looser in Shares...because of the dwindling economy.

Unemployment is rising – Many economists say, job losses are up 30% in the US and 50% in the UK since 2007. How bad will it get? A conservative estimate says that unemployment will reach at least 5% in Britain and 8% in US.
With the US economy officially in recession and other major economies set to follow suit, the spectre of rising unemployment once again occupies the minds of policymakers and media pundits alike. At any point in time, many workers flow into and out of the unemployment pool. Increases in unemployment are preceded by a rise in unemployment inflows as jobs are destroyed, followed by a rise in the duration of unemployment spells as workers fail to quickly find new jobs.
A natural question, is whether the recent ramp-up in US unemployment has evolved any differently. Despite many similarities with previous recessions, the rapid inflow of workers into unemployment during the current downturn confirms that this is one of the most severe recessions in recent history.... I would say this is Global down turn as most of countires are affected by this recession.

After going through various different economic sites and news, here is what I realised will be the recession proof.

1. Health care jobs will be plentiful. Even in bad financial times, people need to see the doctor. Any health care related profession is a good area to be in.
2. Alternative energy will be a growth field, especially for engineers [Energy efficiency - including the reduction of energy loss - will probably also become a hot area]
3. Anything which helps people save money will be in demand.

Sunday, February 8, 2009

Random Thoughts on Valentine's Day.....

Feb 14 is invented by greeting card companies to make people feel like a crap. I don't know why??????........ I am an impulsive person.

Love is in the air.. In this world people are dressed RED & Pink. Few Places will be decorated with red balloons. Some spots will be decorated with flowers. I don’t want to sound stereotypical by uttering this boring sentence "Every day is a valentnie day…wat’s so special on Feb 14? one can celebrate it any time and day they want".

But, I do believe that its just another day like other days. The question is if anyone want to gift their dear ones something special, would valentine day be the apt day to gift?
For me, I think any other day will be a bigger surprise for the gal/boy. Just imagine, if we gift our parents, teachers on any random day...that would be lot more fun and exciting, rather than being obedient and gifting only on the so called Teacher's/Father's/Mother's Day.

I don’t mean celebrating Diwali in April and Christmas in August, as these festivals are something related to cosmic timings and close to religion. I will categorise all above mentioned days as Social Days (Teacher's, father's,Mother’s,valentine's day etc.) Social days can never be limited to a fixed day and timing for celebrations. Social Days are for someone very special and personal and therefore doesn’t need any predecided day for celebrations.

It’s for the people to decide how they weigh these day's in their life's.

7 good things Valentine's should have:

1. Intelligence and Wit
2. Sense of Humour which should be good enough to appreciate jokes levelled at oneself
3. Modesty and a down to earth attitude
4. Same wavelength thinking and Common Interests
5. General Goodness
6. Friendly and an easy going attitude
7. Looks that appeal to each other

Wednesday, February 4, 2009

Food and Habits!

I dislike wasting/ throwing away food in any form, more so when prepared at home. I feel we are wasting the money spent for the ingredients used, time used to buy them/ make the dish, the efforts involved in preparing it and most importantly I feel we’re depriving someone else a meal by throwing it away. I don’t know how extreme this behaviour might be considered, but I strongly feel that way.
Though this feeling - that wasting food is wrong, was always there within me somewhere, it had not come to the fore as it has now, when I am staying here on my own. My mom always used to insist that I and my sister should not waste anything. Even if there were some leftovers we would re-heat and eat it, as long as it was not stale, or it would be given to the maid or somebody else in need of it. At that time, though we did follow it, we would complain sometimes.
But now I realize exactly how she felt and why she said so. In the past months, I have had to encounter people who have no such qualms. They have no second thoughts when they have to throw away food – whether home-made or from the reataurant doesn’t seem to matter to them. I have a terrible time bearing such behaviour and it upsets me badly :(My thoughts are simple – if you don’t like eating some vegetables or dish, don’t buy them or just prepare as much as you need. I know that it is always not possible to prepare the exact quantity and there are unforeseen circumstances which might come up due to which the food can’t be finished, in that case see if it can be eaten for the next meal, by keeping in the refrigerator. Please, do make an effort and don’t just take the convenient escape route of dumping it in the bin! I guess it has to do with the manner in which one is brought up and the values one is taught, as one grows, realizes and gains understanding of the ways of the world. I am thankful that my parents taught me this important lesson that one should be grateful for every morsel one gets to eat, there are thousands who’re deprived of even that. I just hope that others too realize this, even if nobody ever told them so… ‘coz its never too late to learn.

We won the Series--Cricket

Yesterday was truly remarkable – not because India won a cricket tournament, not because it was a resurgent young Indian team sans all the stars and pillars and what-nots (there have been such false starts in the past as well); not because we literally steam-rolled all opposition throughout our journey to the finals. I t was remarkable for me, because thousands of miles away, in a foreign country, I was watching the exciting match, in all but a tiny slot of the mosaic pattern of channels on the TV screen (the subscription rates for cricket channels in this country are incredible!), the commentary on at full volume, jumping up and down, shouting and cheering at every wicket, with a equally cricket-crazy roomie.

When I think back, it was a wonderful feeling. But the bottom-line is, we won. It almost seemed like India was destined to win this one, looking at their performance from the beginning. As someone aptly said, cricket is not a sport; it’s a religion. It binds us all together, no matter where and what soil we are on!