In a previous post, I talked about several robots used to fight oil spill at the Gulf of Mexico. Today I will focus on only one of them -- the iRobot 1KA Seaglider.
The Seaglider robot was originally developed by the Applied Physics Laboratory at University of Washington. It is submarine like UUV (Unmanned Underwater Vehicle) or AUV (Autonomous Underwater Vehicle) used to collect oceanology data under the surface of ocean water. (Go here to see more pictures.)
Seaglider ready to launch (Photo credit APL-UW)
Seaglider in action (Photo credit APL-UW)
Seaglider is 1.8 meter long with wing span of one meter and weighs only 52 kg dry. Powered by 24V Lithium battery, Seaglider has a cruising range of 4600 km and can dive up to 1000 meters. As shown in the short animation below, the robot doesn't have any propeller and flies through water using changes in buoyancy for thrust. This minimum energy consumption allows the robot to stay in water for very long missions that many times last months long.
The Seaglider robot had been used to "track deep-diving mammals by their high-frequency clicks and squeals." It had also been deployed to the poles months underneath the sea ice for a study of climate change as shown in the video below. Every once a while, the robot would surface and then using the long antenna in its tail to send data to a satellite, which then become accessible from web-enabled devices. The operator can also upload preset way points to the robot for it to survey a certain region. The robot is also capable of loiter and drift modes that will allow the robot to maintain neutral buoyancy at any depth.
In June 2008, the Massachusetts based robotics company, iRobot (yes, the one that makes the popular home vacuum cleaner robots), purchased the Seaglider technology to mass produce it for military use. With its top speed at 25 cm/s, I'd think the robot is probably going to used for reconnaissance use instead of the more action-packed 007 style attacking missions. However, at $100,000 a piece, I don't know if this is tax money well spent. In the BP Oil Spill Crisis currently in progress, iRobot has sent several of this sleek autonomous submarines to the Gulf of Mexico to help collect ocean data and track the movement of the oil spill.
Obviously, this robot is only good for the very patient type users. However, I just can't help asking this question, "if, by any chance, the robot gets swallowed by a big fish, will the fish get diarrhea?"
Picture of the Day:
How often do you see this man in a suit? And can you believe these two used to be teammates?
Argentina's coach Diego Maradona (L) speaks to midfielder Juan Sebastian Veron after substituting him during their 2010 World Cup Group B soccer match against Nigeria at Ellis Park stadium in Johannesburg June 12, 2010.
Photograph by: DAVID GRAY Credit: REUTERS
The Deepwater Horizon drilling rig burns as oil
pours into the Gulf of Mexico.[The Canadian Press]
If you follow the news somewhat, then you probably have heard about the Oil Spill at the Gulf of Mexico. The BP-owned well has been leaking for nearly two months, causing great disaster to the environment and ocean lives. In the process of fighting the oil leak, many new robotics technologies were put to test and proved to be very handy tools for gulf researchers.
iRobot Seaglider Robot
One robot used is the iRobot Seaglider, a deep-diving UUV (Underwater Unmanned Vehicle) used to detect and map leaked oil in the gulf. Seaglider was originally developed by University of Washington and later acquired by iRobot in June 2008. The robot is powered by changes of buoyancy and does not need a traditional propeller, which allows it to go on missions that last many months long. Sensors on the robot can detect levels of dissolved oxygen in the water, temperature, salinity, other ocean properties, and the presence of oil all the way down to 1,000 meters. The robot has been used to locate and monitor clouds of dispersed oil droplets. Data can be uploaded to a satellite and then distributed via the web to any web-capable devices around the world.
Scripps Glider: Spray
Another robot used is the Spray robot, which is also a submarine type underwater glider, developed under ONR (Office of Naval Research) support by Scripps Institute of Oceanography and Woods Hole Oceanographic Institution Scientists. The robot is "fitted with a sensor similar to the one used used to measure chlorophyll, which is essential for the growth of plants." Scientists hope that the sensor can also pick up the spreading oil leak. The glider can dive up to 1,500 feet deep, and then periodically surface to relay data back to the scientists. It is also possible to use an i-Phone to command the glider, such as telling it to go up or down, turn, or to turn on/off sensors.
BP engineers also used ROV (Remotely Operated Vehicles) type robots to wield clamps and haul machinery in slow machine below the surface of the gulf to cap the renegade well. Video feeds showed the robots using a circular saw-like device to cut small pipes around the leaking riser. I cannot find more information about what kinds of ROV robots were used, but from the video below (from the perspective of the ROV robot) you can see that the ROV robot had arms and grippers tele-operated by human operators to perform manipulation tasks.
Isn't it amazing that we see robots everywhere these days? They are in the air, under the sea, and even in people's homes (not mentioning those ones on other planets). I sure have picked the right career! :)
Picture of the Day:
Giant Isopod that hitched a ride on an ROV in the Gulf of Mexcio. The subject of Isopocalypse 2010.
On June 3, 2010, the third stage of the Mars-500 Project kicked into gear at the Russian Academy of Sciences' Institute of Biomedical Problems in Moscow, Russia, where six volunteers from four different countries would spend their next 520-days inside a locked experiment facility simulating a long enduring trip to Mars.
The Mars-500 project is a ground-based experiment simulating manned flight to Mars. The main purpose of the experiment is to evaluate how the long isolation, especially the 20-minutes delayed communication with the outside world, affects the state of health and working capability of the crews.
The project has three stages. The first, 15-day stage took place in 2007 and was only designed to test out the facility. The second, 105-day stage happened in 2009 with 6 volunteers living in the isolated living complex. Currently in progress is the third stage, and another 6 volunteers will actually simulate a complete 520-day mission to Mars -- yes, that's how long the round-trip takes.
The 6 volunteers (professional astronauts, scientists, and engineers) will spend the entire duration of the experiment in a sealed facility with no windows and a '20-minute, one-way time-delay in communications to mirror the real lag in sending messages over the vast distance between Mars and Earth. It's almost like serving an 18-month jail term, but only worse, because they won't ever see the sun and have to live off canned food. They will also be under constant supervision and will be going through many scientific tests each day.
I have always been a big fan of space exploration. Call me Chicken Little if you wish, but with enough nuclear bombs that can blow up our planet over 300 times with only the push of a button, and with so many maniacs in this world, we've got to spread the seeds for human kind before the dooms day, before we wipe out ourselves completely from this universe. Therefore, great shout outs to these 6 volunteers who are willing to make the sacrifice for the benefit of the entire human race (think of all the World Cup games they are going to miss!!). I wish them a very productive "journey" and the greatest success! If I ever get locked up for 18 months, the entire book of Smiling Proud Wanderer would have been translated. LOL!
In order to successfully establish human outposts (or colonies) on another planet, it is essential to have intelligent worker robots working alongside human crews. Although we already have several robots roaming on top of the Martian surface, they are mainly for scientific exploration. What we really need are robots that can work as a team building/assembling equipments and living complexes. Some of them can be sent to Mars before the humans to get things started. Because of the long distance and long communication lag, they would have to be quite capable of autonomous operations, probably at some basic level tasks. Then more robots would go along with the human crews. These robots don't have to be fully autonomous, but will need to be able to interact with human well and take directions/supervisions from human operators efficiently/effectively. Robots have great advantages over human for these kind of space exploration because they don't need to eat, breathe, be entertained, and will never need a psychiatrist during such long space trips.
Picture of the Day:
The South African players dancing on the sideline in celebration of their goal against Mexico in the 2010 World Cup. It is so wonderful that the host nation gets to score the first goal of the tournament! Go Africans!
This paper was written by Meila (MIT) and Heckerman (Microsoft Research) and published at the Machine Learning journal in 2001.
This tech report compares three batch clustering algorithms: EM, CEM, and HAC and also investigate the effect of three different initialization schemes on the final solution produced by the EM algorithm.
The clustering algorithms first use the log posterior probability of model structure given the training data log P(K|Dtrain) to select model structure, and then learn the parameters of a given model structure. The EM algorithm is iterative, and in the E step, assigns the case fractionally to each cluster. The CEM algorithm assigns the case fully to the class k that has the highest posterior probability given the document and the current parameter values. The HAC algorithm merge smaller clusters by recursively merging the two clusters that are closest together until only K clusters are left. The authors derive the distance metric for mixtures of independent multinomially distributed variables.
The three initialization methods experimented are: the random approach where the parameters are independent of the data, the noisy-marginal method (data dependent), and the method of using HAC on a random sample of the data. Several performance criteria are used. For the model structure, the log-marginal-likelihood criterion and the difference between the number of clusters in the model and the true number of clusters are used. For the entire model, one criterion is the cross entropy between the true joint distribution for X and the joint distribution given by the model, and another criterion is the classification accuracy. Running time is also used to compare algorithms.
Experimental results from two datasets were reported. The synthetic dataset was constructed using the MSNBC news service, and the digits dataset consists of images of handwritten digits made available by the US Postal Service Office for Advanced Technology. For both datasets, EM outperformed CEM for all initialization methods and for all criteria (except that CEM is four times faster than EM). After constraining EM run time to match CEM, EM still performed better. When comparing EM versus HAC (initializing using Marginal method), EM is clearly better.
When comparing initialization methods, for the Synthetic dataset, Marginal and HAC are always better than Random (for all criteria) with no significant differences between themselves, but Marginal is much faster than HAC. For the digit6 dataset, there is no clear winner.
Picture of the Day:
First time ever a rescue helicopter landing in Bryce Canyon, Utah. The chopper landed right on the top of the ridge. Got to give the pilot some shout out for his awesome skills!
A voice came from outside the iron-door, “Mr. Ren, it has been very hot in the last couple of days. May I ask if the revered mister still enjoys his good health?”
As soon as Linghu Chong heard the voice, he recognized it instantly. It was the voice of Mr. Black-White. If he had come to his cell one month before, Linghu Chong would have shouted all kinds of invective at him with no scruples. However, after many days of imprisonment, his anger had mollified a great deal and he was able to think calmly.
“Why did he call me Mr. Ren? Has he come to the wrong cell?” he thought to himself and decided to remain silent and listen on.
“Every two months, I come and ask the revered mister the same question. Today is the first day of July, so please allow me to ask once again: Will the revered mister grant my request?” Mr. Black-White continued, his tone respectful and cautious.
Linghu Chong laughed inwardly. “He got the prison cells all mixed up and must have thought I am the Revered Mr. Ren. How careless of him!” But immediately after, he felt a chill in his heart. “Mr. Black-White obviously is the most meticulous one among the four Masters of the Plum Manor. It might be possible for Mr. Bald-Brush or Mr. Paint to mix up the prison cells, but how could Mr. Black-White actually make such a mistake? There must be a reason behind this.” With that in mind, he kept his silence.
Mr. Black-White continued, “Revered Mr. Ren, valiant and capable all your life, why let yourself languish with the decaying dust in the underground dungeon? My words are as firm as the mountain. If the revered mister grants me my request, I promise I will help the revered mister get out of this prison.”
Linghu Chong’s heart thumped wildly. Many thoughts raced through his mind, but he failed to put them in order. What was Mr. Black-White really after and why did he speak this way? He simply couldn’t figure it out. Then he heard Mr. Black-White asking a second time.
“Will the revered mister grant my request?”
Linghu Chong knew that this could be the very opportunity for him to escape. Despite any possible ill intentions, it would still have been a much better alternative than getting stranded forever in the underground prison for some unknown reasons. But having no way of identifying Mr. Black-White’s true intention, he bit his lip and remained silent, afraid that he might say something wrong to ruin this precious opportunity.
“Revered Mr. Ren, why aren’t you speaking up?” Mr. Black-White heaved a sigh. “Last time, when that boy Feng challenged you in the art of sword, you didn’t mention a single word about my request in front of my three sworn-brothers. I am truly grateful for the kindness. I thought to myself, the sword fight must have brought back the many fond memories and the lofty sentiments in Revered Mr. Ren’s heart, and reminded him of the vast world outside. If your Excellency could break out of the dark dungeon, the entire world would be yours for the taking, and you can snuff out any mundane life at will, whether male or female, old or young; and no one would ever dare defy your wish. Wouldn’t that be exhilarating? Granting the request would not have brought any nuisance to your own. Why wouldn’t you ever consent in the past twelve years?”
Linghu Chong could sense the sincerity in his voice. Apparently he really thought he was addressing senior master Ren, which puzzled Linghu Chong even more. He listened on as Mr. Black-White begged again and again for him to agree to the request. Linghu Chong really wanted to know more details about the request, but he reckoned that the situation would take an immediate bad turn if he opened his mouth. Holding his tongue forcibly with great effort, he dared not make the slightest sound.
“If the revered mister is still so stubborn, I guess I’ll visit him again in two months,” Mr. Black-White concluded. He suddenly let out a few chuckles. “The revered mister didn’t scold me this time. Maybe there’s a favorable turn in the situation. I hope the revered mister will give my request some good consideration in the next two months.” After those words, he turned around to exit.
Linghu Chong became quite worried. It would be another two months before Mr. Black-White would return, and how could he stand another two months of the miserable life in the pitch-black prison? He waited until Mr. Black-White had taken several steps and then spoke up in an intentionally lowered and coarse voice.
“What request shall I grant?”
Mr. Black-White turned around at once, and with a swift leap, he had returned back to the square-shaped opening.
“You will…you will grant me my request?” His voice trembled.
Linghu Chong turned to face the wall and covered his mouth with his hand.
“What request?” he said in a muffled voice.
“In the past twelve years, I would take on great risks to come here six times each year, just so that I could implore for the revered mister to consent. Why is the revered mister asking when the answer is so obvious?”
“I forgot!” Linghu Chong snorted.
“I would like the revered mister to teach me the secret of the magical art. Once I master the skills, I promise to let the revered mister out of this place.”
“Has he really mistaken me for that senior master Ren, or is this some kind of intrigue?” Linghu Chong pondered. Still having no clue about Mr. Black-White’s true intentions, he mumbled something indistinct, not even knowing what he said himself.
Naturally, Mr. Black-White didn’t understand a word of his, and had to ask again and again, “Will the revered mister grant it? Will the revered mister grant it?”
“You don’t live up to your promise. You won’t fool me,” Linghu Chong replied.
“What kind of guarantee would I have to provide so the revered mister will believe my words?”
“What do you have in mind?”
“I understand the revered mister’s worries. What if I break my promise after the revered mister teaches me the secret of the magical art and still not let him out? There is no need to worry! I have it all arranged, and the revered mister can put his trust in my arrangement,” Mr. Black-White answered.
“What arrangement?”
“Does this mean the revered mister will grant me my request?” Mr. Black-White asked quickly, his voice filled with excitement.
Linghu Chong thought very quickly, “He wants me to teach him the secret of the magical art. Where the heck would I find this secret of the magical art? But I might as well check out his arrangement. If he really will let me out of this place, I could just give him those meditation techniques carved on the steel plate. Who cares if it works or not, it doesn’t hurt to give him some false hope.”
When Mr. Black-White didn’t hear an answer, he added, “After the revered mister teaches me the magical art, I would have automatically become an apprentice of the revered mister. In our cult, an apprentice who deceives his master is to be skinned and dismembered alive. In the past several hundred years, not a single one had managed to get away from the harsh punishment. How would I ever dare to not let the revered mister out?”
“I see,” Linghu Chong let out another snort. “Come back in three days to get your answer.”
“Why won’t the revered mister grant my request today? Why wait another three days in this dark dungeon?” Mr. Black-White pleaded.
Linghu Chong thought to himself, “He is even more impatient than I am. It might be a good idea to wait three days and see if he’s going to pull some clever tricks.” At that thought, he produced a loud, disgruntled humph as if he was very annoyed.
“Sure! Sure! I shall return in three days so I could ask advice from the revered mister again!” Mr. Black-White hurriedly agreed.
Linghu Chong listened as Mr. Black-White walked out of the underground tunnel and closed the iron gate while many unsettling thoughts swirled inside his head.
“Could he really have mistaken me as the Ren-named senior master? He is a very meticulous man. How could he make such a silly mistake?”
Suddenly, an idea struck him. “Could it be possible that Mr. Huang-Zhong found out about Mr. Black-White’s visits and secretly moved senior master Ren to another cell, then put me in this cell instead? That’s got to be it! In the past twelve years, Mr. Black-White had been paying a visit every other month. It’s very likely that someone found out about it. It must have been Mr. Huang-Zhong who set up this scheme clandestinely.”
Then, he remembered what Mr. Black-White had said earlier. “In our cult, an apprentice who deceives his master is to be skinned and dismembered alive. In the past several hundred years, not a single one had managed to get away from the harsh punishment.”
“Our cult? Which cult?” he thought it over. “Could it be the Demon’s Cult? Is it possible that the senior master Ren and the Four Skunks of Jiangnan are all members of the Demon’s Cult? What kind of game are they playing? Why are they dragging me into this mess?”
As soon as the name “Demon’s Cult” came to his mind, he found the entire matter surreptitious and beyond his comprehension, and decided to not ponder upon it. Instead, he concentrated only on two things: “Was Mr. Black-White sincere or was he just acting it up? How shall I answer him when he comes back in three days?”
All kinds of strange idea went through his mind, but no matter how hard he tried, he still couldn’t figure out Mr. Black-White’s true intentions. After some time, he became extremely weary and fell asleep. By the time he woke up, his first thought was, “If brother Xiang were here, with his experience and knowledge, he would have guessed Mr. Black-White’s intention in no time. That Ren-named senior master was also very bright, likely even smarter than brother Xiang…oops!”
He suddenly cried out and jumped to his feet. After the nap, his brain functioned much better and he realized something.
“For the last twelve years, senior master Ren never granted him the request. Why? Because he knew very well what would happen if he did. As sharp and experienced as he is, he clearly knew the pros and cons of the matter.” Then he thought to himself, “Although senior master Ren should not grant the request, I am not senior master Ren. Why can’t I?”
He knew he shouldn’t do it. He could even smell the great danger involved, yet the hope of escape weighed heavily on his mind, and he would risk the greatest calamity just for an opportunity to break out from the dark underground dungeon. He soon made up his mind.
“When Mr. Black-White comes back in three days, I will consent to his request and teach him the inner energy cultivation and meditation techniques carved on the steel plate. Then I’ll just act according to his reactions.”
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Video of the Day:
One of the best fighting scenes in Kung Fu movies --- Jet Li's Fist of Legend
