Sunday, October 16, 2011

Filled Trip

OVERVIEW
Field Trip and Seminars, based on the definition of http://en.wikipedia.org/wiki/Field_trip, is a journey by a group of people to a place away from their normal environment. The purpose of the trip is usually observation for education, non-experimental research or to provide students with experiences outside their everyday activities, such as going camping with teachers and their classmates.
Just last September 20-25, we had a Field Trip and Seminars in Metro Manila. Field Trip and Seminars is one of our courses for this semester.  We are the second batch who took this course. This was added to our curriculum with the aim of educating us about the new technologies that different large companies are using.
During our 5-day trip, we visited different companies around Metro Manila. Though the companies differ in nature from one another, the common thing about them is that they use technology in improving the productivity of their company. Each company prepared a couple of presentations about their company and the different technologies they are using. They also gave us the chance to see these technologies and gave us details about it.
We have planned for the Field Trip and Seminars for a couple of months. We paid quite a large amount of money that is due for all our expenses for the trip. But I must say that all the efforts and the amount we paid are worth it. I went to Manila not sure of what will happen to me after graduation or if I really want to be in this field, but I went home to Davao loving myself for choosing Bachelor of Science in Information Technology and I am now sure that a bright future awaits me. In our visit to the different companies, I saw that there are different things that an IT person can do and I love it. Each day of the trip made our minds full with different new knowledge about our field. The whole trip fired up my passion for what I am doing.


DAY 1
            September 20, 2011, Tuesday, was the first day of our Field Trip to Manila which we have been planning for months.  I woke up early out of excitement and maybe because I was afraid that I might get left behind. At around 4:20 in the morning, my classmates and I were already gathered in front of the airport. It took almost an hour for all of us to check in. After all of us have checked in, we stayed in the terminal and waited for our flight. At around 6:20, we boarded the plane. I was excited and at the same time nervous because it was my first time to ride an airplane. The one and a half hour trip went on smoothly.
At 8:15, we arrived at Manila. Outside the airport, our bus was waiting for us along with Ma’am Mae Ann and Kuya Byron—our tour guide. We went directly to our first company visit at the Philippine Long Distance Telephone Company at Mandaluyong City. We had our breakfast on board during our travel to PLDT because we were in a rush to arrive at PLDT on time. We didn’t want to be late because from what we heard, PLDT is strict, especially when it comes to schedules and time. Good thing we arrived at PLDT at exactly 9:00 in the morning. We explored the Innovation Laboratory and Telecommunications Education Center of PLDT or simply known as the Innolab. The first part of the tour was all about the history of PLDT. The guide discussed about how PLDT started and the different ages PLDT had gone through. PLDT had been in the business for around 83 years. Since its beginning, PLDT faced a couple of obstacles and had even fallen but was able to rise again. And this time, PLDT started to grow rapidly. The company was a great help in the economy of our nation. It was able to employ quite a large number of Filipino. From 1998 up to the present, the Chairman of the Board of PLDT is Mr. Manuel V. Pangilinan, also known as Manny, a Filipino business man. Along the rapid change of technology, PLDT was able to cope with it. They use these new technologies to improve the service they can offer and develop the products that they can give. PLDT had grown. Smart, the largest wireless network provider in the Philippines is now, PLDT’s sister company. The second part of our visit to PLDT was a short presentation from Mr. Edmund Mamboyo. In the presentation he said that PLDT is only selling the wire that is connected to the telephone of their customer and that the service they offer is optional. He discussed about the networking of PLDT around the country. He was also able to mention about the Fiber to the Home or FTTH which they will be launching this year. According to PLDT, FTTH uses fiber optic technology which transmits data via light signals sent through hair-thin strands of pure glass. Instead of the usual copper going to the homes of customers, thin fiber optic cables will be used. The new platform will be able to deliver simultaneously voice, video and data services at much higher speeds and larger capacities than DSL or cable technologies. They also said that it is a quantum leap forward in terms of broadband services and that it demonstrates PLDT’s commitment to offer its customers cutting edge communication technologies. When Mr. Mamboyo finished his presentation, I thought that we were already done with our first company visit but I was wrong. The third and last part of the trip was the part I liked the most. They showed us the different technologies that they are using and some technologies that they are working on and will be launched in the near future. They are developing technologies that will surely improve every aspect of people’s lives. PLDT is currently developing different technologies for homes and businesses. Our visit to PLDT filled our brains with knowledge and information with new things regarding the use technology. I just feel that it lacks a little more because though they were able to show us the technologies they are developing, they were not able to tell us much about it maybe because of some confidentiality reasons. At around 12:30 in the afternoon, our first company visit was done.
After our visit, we had our lunch, still on board. But unlike our breakfast, we were really able to taste our food in the lunch. We did not have to rush because our next company visit is scheduled at 2:30 in the afternoon and we still have a lot of time. After everyone finished eating we headed our way to SPI Servisoft at Paranaque City. Though the trip to Paranaque was quite long, we were not bored because of Kuya Byron. He was like a walking history book. I bet he knows everything about all the cities of Metro Manila. He keeps on telling us things about all the remarkable places that we pass through. And every time he wants us to see something, he’ll point at it and say, “There oh”. Our travel time was about a quarter of an hour. We arrived early and were still ahead of our scheduled visit time. Kuya Byron negotiated with someone from SPI if we could start our visit to their company earlier than what was scheduled. Luckily SPI agreed. The first part of the visit was a presentation. They discussed about what SPI Servisoft is all about. SPI Servisoft is a BPO or Business Process Outsourcing. A BPO, from the definition of wikipedia.com, is a subset of outsourcing that involves the contracting of the operations and responsibilities of specific business functions (or processes) to a third-party service provider. SPI offers a host of IT-oriented services that support the creation, conversion, management, and presentation of enterprise content to deliver cost-effective business solutions and improved business performance. They also discussed about the networking in their company and about the System Development Life Cycle or SLDC which is a conceptual model that describes the stages involved in an information system development. After the presentation, they gave us a tour around different workplaces in their company. Every workplace is divided into teams. Each team has a task different from the others. They introduced us to some people who are the team leaders of a team and they gave us an idea of what their team is doing. I was amazed with one of the workplaces which work with how the books look like. I thought arranging the content of a book is easy but   I guess I was wrong. I saw that the people on that place were really serious and focused on what they’re doing. It seems like they need a deep concentration. We finished our visit at SPI with a picture taking with some of their employees. I did not like that much the first part of the visit. The presentation seemed an orientation for new employees. What I liked on the visit was the tour but they were not able to explain thoroughly what every workplace does and how does it work. At around 5:00, we were already done with our company visit for the first day of our field trip.
Base on our itinerary, after every company visit, we will have a shopping in different malls. Immediately after our visit to SPI, we went to the biggest mall in Asia—the SM Mall of Asia. We did a little walking around the mall. I did not enjoy that much because I was already exhausted from the day’s activity and all I wanted to do was to take a rest. At around 7:30 in the evening, everyone was already in the bus. We started our way to Kabayan Hotel where we will be spending staying for the whole duration of the trip.
When we arrived at the hotel, we went directly to our rooms. We took a quick rest before going to dinner. We had our dinner only at the hotel. The food was delicious and it made me full. Somehow, I regained my energy. We decided that since we are already in Manila, we will take this opportunity to see different places. We were also told that there are night markets where different stuffs were sold at a very cheap cost. After our dinner, we decided to go to Baclaran Church.  Our side trip took about two hours. When we returned to the hotel it was almost 11:00 in the evening. When I lay down my bed, it did not take long for me to go to sleep and the first day of our Field Trip was over.

DAY 2
September 21, 2011, Wednesday— second day of our educational trip. Our day started early. We all woke up at 4:30 in the morning. We prepared ourselves for today’s activity—the Philippine Youth Congress in Information Technology or Y4IT. The Y4IT is considered the biggest IT gathering in the country. Its aim is to provide a venue where IT experts and practitioners, industry players and academics can share to students and computer enthusiasts alike current researches, trends and developments in IT and hopefully inspire audiences to take the forefront in shaping the future of the Philippine IT industry. We had our breakfast in the hotel. We were scheduled to leave the hotel at 6:30 in the morning. It was still 6:00 when everyone was already in the bus so we departed earlier than what was scheduled. When we arrived at UP Diliman, the event did not started yet but the place was already very crowded. We went to the University Theater. At around 9:00 in the morning, the congress started. The welcome remarks was given by no other than our dearest instructor, Sir Randy S. Gamboa. The key note was given by Vicente Sotto III, senator of the Philippines. After Mr. Sotto’s speech, we had a break. We went outside the theater to get some food. When we returned, someone was singing and I was shocked to see that it was Liezel Drillion and Hansen from the Philippine Dream Academy. After we were refreshed by the intermission number, the congress went on to the program. The topic was about game development. Two speakers, both from the International Game Developer’s Association, discussed about the topic. Every talk or speech was short to make sure that everything in the schedule would be followed.
Around 12:00 noon, the first part of the congress was finished. Outside the theater, there was a stall giving out freebies, and because it was still early for our scheduled lunch, we took the time to grab the opportunity. We returned to our bus and had lunch. I must say that, so far, every meal served to us makes us very full that’s why I also call our field trip a “Filled” trip.
After an hour of lunch break, we went back for the continuation of the congress. This time, we went to the Film Institute. When we entered the Film Institute, someone was already giving her talk. The speaker, Mr. Yung-Cheol Bun, from Jeju National University, discussed about Smart Life and Smart Applications. It was fun. Everything that he needs to do is in his phone. He discussed his activities in a day and talk about how Smart Life and Smart Applications can help him in every activity. The next topic was about competitive computing. After the talk, we had a break. We went out of the Film Institute but instead of returning, we went to another building. We went to the Bahay ng Alumni. We did not sit down and listen to different speakers this time. We just went to see the different exhibitors. The congress did not last long. We decided to ride the UP Ikot—the name of the jeepneys inside the campus. We went to see the famous UP oblation. We had a picture taking and headed our way back to the bus. Before we went to Trinoma Mall, we stopped by a souvenir shop inside UP. We also had a picture taking again in the oblation, this time with the whole class. We also went to the famous Pinoy Big Brother House and took some pictures outside. And finally, we went to Trinoma. What I liked about the mall is that it has a mini park inside. After two hours of window shopping, we went back to the hotel. On our way back, everyone fell asleep, of course except the driver.
We had our dinner, still at the hotel and just like the first day, no matter how tired we were, we decided to go on a side trip. After dinner we went out to experience riding the MRT/LRT. It was again a first time for me and it was really fun. After strolling down the streets, we decided to return to the hotel. This time, MRT/LRT stations are already closed so we rode a bus. We arrived at the hotel before 11:00 in the evening. As I lay down my bed, sleep easily found its way to me and the second day of our trip was over.

DAY 3
            September 22, 2011, Thursday-- third day of our field trip. Just like the day before, our day started early. We prepared ourselves for another company visit. We ate our breakfast at the hotel. We waited on the bus, when we were already complete; we started our way to our next company visit.
Fluor Daniel is located in Alabang. Just by riding the elevator, I can see that this is a great company to work in. Just like the other companies, Flour prepared a presentation. The first topic discussed was about the six things that a person must have in order to achieve success. Then they talked about the company overview. Fluor is one of the world’s leading publicly traded engineering, procurement, construction, maintenance, and project management companies. They also discussed about the company’s IT Service Delivery. I liked it because the things that they discussed were all related to us. Before going on the next part of the visit, they gave us food and some souvenirs from their company. What I liked in our visit to Fluor was the tour around their company. We were able to see different workplaces inside the company and they also gave us the chance to see their data center. In the data center, it was unusually freezing. Someone from the company explained that it is to maintain the security of the place. The data center, of all places of the company is the one that must be greatly looked after. The employee discussed about the different devices in the data center and how each device works. We did not stay longer because we would soon turn to ice. In our visit to Fluor, I said to myself, “I would want to work here in the future”.
We had our lunch at a mall just near Fluor Daniels. Our next company visit was still scheduled at 2:00 in the afternoon. We still had a lot of time to stroll inside the mall. When we were already tired, we went back to the bus. We stayed in the bus for about an hour and watched a movie. It was raining outside.
At around 1:00 in the afternoon, we started heading our way to our next company visit—to the Department of Science and Technology. We arrived at DOST early so we started early than what was scheduled. Someone from DOST is a dabawenyo. He discussed about IP address, particularly about IPv4 which is slowly running out of addresses. The solution to this is the IPv6 which is a 128 bit addressing scheme. They also discussed about the different websites of DOST. The visit did not last long. We were again ahead of schedule so we decided to visit the DOST museum. It was full of different works of different Filipinos and the profiles of the famous Filipino scientists. After about an hour of roaming around the museum, it was time to proceed with our schedule. I did not like our visit to DOST. It was like we just went there to hear someone talk about IPv4 and IPv6. We already discussed it in the school.
At around 4:00 in the afternoon, we went to Market Market for our shopping schedule. We saw a stall of the famous Krispy Kreme. We agreed to have a taste of it. Inside the mall was a bazaar where items were sold at really cheap prices. We took the opportunity to buy some pasalubongs for our family and classmates. After about two hours of shopping, we got tired and decided to go back to the bus. When we were already complete, we started our way back to the hotel.
After dinner we had another side trip. This time, we went back to SM Mall of Asia but not to stroll around the mall but to go to San Mig by the Bay. It was the perfect place to really have fun. There were live bands playing in the restaurants, there were also stalls of food. It was a park just beside the bay. We stayed later this night. We arrived at the hotel just before it strikes 11:00 in the evening. We did not immediately went to sleep. Some of my classmates bought French fries from McDonald’s. We had a little chitchat before going back to our own rooms. At around 12:00 midnight, I lay down my bed and realized that the trip will soon be over. It made me sad and thinking about it made me fall asleep and the third day of our trip was over.

DAY 4
            September 23, 2011, Friday—fourth day of our educational tour and also the last day of our company visits. Our day started later than the other days. We did our normal routines. We prepared ourselves and ate our breakfast at the hotel. Our scheduled company visit for this morning is at the Social Security System or SSS.
At around 8:30, we arrived at SSS. We were again ahead of schedule. We went inside and waited for them to finish their preparations. They prepared a presentation for us. They discussed about what social security is all about, what are the features of SSS, its coverage, its contributions, and all other stuffs about SSS. It also did not last that long. After the presentation, we had a picture taking together with some of the employees and then after, we had a tour to where different SSS transactions are held. I also did not like it because they discussed all about SSS and did not see its connection to us. I wanted to hear something from their IT department-- what are the things they do and how do they do it. Also, there was nothing in the tour. It was just like a typical trip to SSS when you transact or process your SSS membership. I was disappointed because I really wanted everything to happen great because its our last day for company visits.
At around 12:00 noon, we went to Tramway—an eat-all-you-can buffet located in Mandaluyong City. We had our lunch there. We ate for about an hour. We were very full when we returned to the bus. We still have more time for our next company visit so we went to Greenhills. I chose to stay on the bus because I was not feeling well. I slept for about a quarter of an hour when my classmates returned. When we were complete, we headed our way to the last company that we’re going to visit. At 2:00 in the afternoon, we arrived at Exist Global located in Ortigas Center. We started earlier than what was scheduled. They also prepared a presentation for us. But unlike some of the previous presentations in the other companies, their presentation really relates to us. They discussed about their company and how it works. They also discussed stuffs about what an IT people must be and must not be. I can see that they really value the people working for them. Though Exist is just simple and not that big, I can say that this is the company I want to work for. What I liked most about our visit to Exist is that they were able to satisfy my expectations. They have presented us with the things that we want and we need to know. I just wished that they had toured us around their workplace and explained to us the things that they do. At around 4:00 in the afternoon, our visit to Exist was over and our company visit was finally over.
We did not go to any mall after our visit to exist because we are going to Divisoria tonight and we’re planning to have an early dinner at a time to rest before we go to Divisoria for our shopping. On our way back to the hotel, my classmates and I had a game. Whoever loses will have a punishment. It was a good way for us to get to know each other more and to bond. The trip lasted an hour so we had an hour to get close to each other.
We went to our rooms immediately after we arrived at the hotel. After resting for a couple of minutes, we went to our classmate’s room and stayed there until it was time for dinner. We had our dinner at around 6:30 in the evening. At 7:00, we departed from to the hotel. The trip to Divisoria took about an hour. Everyone was silent inside the bus maybe because we were all tired and we were all sad because our field trip will end soon and we will go back to our normal lives. At 8:00 in the evening, we arrived at Divisoria. We were given until 11:00 in the evening to shop. We strolled around different stalls and were able to buy stuffs for ourselves and for our family and classmates. Before 11:00, raindrops started to fall and we were all forced to go back to the bus. When we were already complete, we went back to the hotel. When we were back in the hotel, everyone got busy preparing their things. We packed our things because we will be living early in the morning. After packing our things, we had another bonding moment because some of my classmates bought French fries and they shared it to everyone. At around 1:00 in the morning, we went back to our rooms. I lay down my bed and did not have the chance to think of anything because I was so tired I easily fell asleep.

DAY 5
            September 24, 2011, Saturday—the last day of our field trip. Our day started later than all other days. We woke up at around 7:00 in the morning. We prepared ourselves, had our breakfast and checked out of the hotel. Today’s schedule was all about having fun. We went to Luneta Park. We had a picture taking together with the famous Rizal Monument. We also rode a kalesa. After going to Luneta Park, we went to the National Museum. There, we were able to see historical stuffs from a shipwreck.  After two hours of strolling in the museum, it was time for us to go back to the bus. We are going to have our lunch at Tutuban Mall because we were also given the chance to have our shopping done. On our way there, we played again. We had so much fun and it made us real close to one another. We arrived at Tutuban Mall at around 12:00 noon. We immediately searched for a place to eat. We ate at McDonald’s. after our lunch, we started our shopping. At 3:30 in the afternoon, we were already back in the bus. We started our way to the airport. We spent the one hour trip just watching a movie because we all got tired from shopping. At exactly 4:30 in the afternoon, we arrived at the airport and it was time for us to say goodbye to our tour guides and to Metro Manila. We checked in at the airport an waited for our flight. We boarded our plane at around 6:30 in the evening and our plane took off. When we were already in the sky and as I watched the lights of Metro Manila slowly fading out of sight, I realized that the amount we paid for the trip was really worth it. It was a Filled trip not just because our stomachs are always full but it was also a trip full of knowledge, fun, and friendship. I hope I can experience this again.


DEVELOPERS CONNECT
            Last September 7, 2011, Wednesday, we had our annual Icean Congress with Developers Connect or known as DevCon. The Field Trip and Seminars students together with the officers of the Society of Information Technology Students (SITS) and the Computer Science Society (CSS) prepared this event.  In our chosen model for the Field Trip and Seminar, team building was a part of it. Instead of having the team building, because the FTS students were only few, we decided to have DevCon as an interpersonal skills seminar. The activity had two parts.
The first part was in the morning. The fourth year Bachelor of Science in Computer Science students had their thesis presentation. Different theses of the different groups were presented in front of the audience from first year to fourth year students both from Bachelor of Science in Information Technology and Bachelor of Science in Computer Science. The presentation lasted the whole morning.
            The second part was in the afternoon. This was the part where people from DevCon presented to us different topics. They discussed about the new technologies they are using and developing.
            After the presentations of the speakers, there was a Birds of Feathers. It was a debate on what operating system is the best. There were three groups with assigned operating system. The operating system assigned to them was Windows, Mac, and Linux. The Windows team won.



What I can recommend for the improvement of the Field Trip and Seminars program:
            Base on my experience, I recommend that the event must be planned thoroughly and without haste. The company that the students would visit must really be thought of. They must be sure that they will gain the proper knowledge from that company.

My advice to those who will take their Field Trip and Seminars in the future:
            My advice to the students who will take FTS is that they must take this opportunity to really learn. It will help a lot in firing up our passion in our chosen field. They must also enjoy their time because this will only happen once.

Tuesday, March 22, 2011

Case 6: Process Life Cycle

    A process is a program in execution. The execution of a process must progress in a sequential fashion. That is at any time, at most one instruction is executed on behalf of the process.

    A program by itself is not a process; a program is a passive entity, whereas a process is an active entity.

    As a process executes, it changes state. The state of the process is defined in part by the followings states:

New
        - The process is being created.
Ready
        - The process is waiting to be assigned to a processor.
Running
        - Instructions are being executed.
Waiting
        - The process is waiting for an event to occur.
Terminated
        - The process has finished execution.

These names are random, and vary between operating systems. However, the state that they represent are found on all systems.

From Ready to Waiting

    There is no transition from READY to WAITING because, as defined, when a process is at its READY state, the process is only waiting to be assigned to a processor. And from the word itself, the process is ready for execution. When the process is already in that state, all the events it needs to execute were already executed before it can be placed in the READY STATE. If we are going to put a transition from READY to WAITING, it would only mean that in the first place, the process should not be in the READY state. Because the WAITING state is still waiting for an event to occur, it is still not ready for execution.

From Waiting to Running

    When a process is interrupted during in the RUNNING process, it is placed in the WAITING state. Therefore, all process in the WAITING list has interrupts and lacks I/O request. A process cannot be placed in the RUNNING state when it lacks I/O request. And when the I/O requests are complete, the process is being placed in the READY state. Thus, it is impossible to have a transition from WAITING to RUNNING.

Case 5: Memory Allocation in Fixed Partition

 Legend: * - Turnaround; ( )- Size; E- Excess memory

First- fit


A. The first batch of jobs is loaded to the memory blocks. Job 1 searches for a block that is big enough. Searching can stop as soon as it can find a memory block that fits. Block 2 is the first memory block that fits Job1. Therefore, Job 1 is loaded to Block 2. Block 1 is the first one that fits Job 2. Block 3 first fits Job 3. Block 4 fits Job 4. Job 5 can not be loaded because Blocks 1 to 4 are already occupied and Block 5 has lesser memory than Job 5. Job 5 is placed in the waiting list.

B. Jobs 2 and 4 terminate and leave the memory block they occupy. Job 5 is loaded first. Block 1 is the first memory block that fits Job 5. Job 6 first fits in Block 4. Job 7 is placed in the waiting list for the same reason Job 5 was also placed in the waiting list.

C.  Jobs 3 and 6 terminate. Job 7 is loaded to Block 3 where it first fits. Job 8 first fits on Block 4. Job 9 is placed in the waiting list.

D. Jobs 1, 5, and 7 terminate. Job 9 is loaded to Block 2 where it first fits. Job 10 is placed in the waiting list.

E. Job 8 terminates. Job 10 is loaded to Block 4 where it fits.

F. Jobs 9 and 10 continue processing.

G. Job 9 terminates. Job 10 is still processing.

H. Job 10 terminates.



Best- fit


A. Job 1 searches the entire list. It is loaded to the block which produces the smallest excess memory or leftover. In this case, Job 1 is loaded to Block 4, Job 2 to Block 5, Job 3 to Block 1, Job 4 to Block 3, and  Job 5 to Block 2.

B. Jobs 4 and 2 terminate. Job 6 is loaded to Block 5, Job 7 to Block 3.

C. Jobs 3, 5, 7, and 6 terminate. Job 8 is loaded to Block 3, Job 9 to Block 2. Job 10 is placed in the waiting list because its memory exceeds the remaining free memory blocks.

D. Job 1 terminates. Job 10 is loaded to Block 4.

E. Job 8 terminates. Jobs 9 and 10 are still processing.

F. Job 9 terminates. Job 10 is still processing.

G. Job 10 terminates.



Worst- fit


A. In this case, the job searches the entire list and is loaded to the block which produces the largest leftover. Block 2 is the block where Job 1 produces the largest leftover. Job 2 to Block 4. Job 3 to Block 3. Job 4 to Block 1. Job 5 is placed in the waiting list.

B. Jobs 4 and 2 terminate. Job 5 searches the list of free memory block. Block 4 produces the largest leftover for Job 5. Job 6 is loaded to Block 1. Job 7 is placed in the waiting list.

C. Jobs 3 and 6 terminate. Job 7 is loaded to Block 3. Job 8 is placed in the waiting list.

D. Jobs 1, 5, and 7 terminate. Job 8 is loaded to Block 2, Job 9 to Block 4. Job 10 is placed in the waiting list.

E. Jobs 8 and 9 are still processing. Job 10 is still in the waiting list.

F. Job 9 terminates. Job 10 is still processing.

G. Job 10 is processing.

H. Job 10 terminates.

Saturday, January 8, 2011

Case 4: Dynamic and Relocatable Partition

There is a total memory size of 220 k. 15 k is allocated for the operating system.

Dynamic Partition

( a) Jobs 1 to 6 were loaded to the memory occupying 189 k. There is still 16 k of memory remaining. Job 7 cannot be loaded to the remaining memory because its size exceeds the size of the remaining memory.

( b) Jobs 2, 4, and 6 terminate, thus, releasing their memory. Job 7 still cannot be loaded because the released memory blocks are still not enough to hold it.

( c) Jobs 3 and 5 terminate and release their memory. This time, Job 7 found a released memory block that is enough to hold it. There are released memory blocks but not one of them is enough to hold Job 8.

( d) Jobs 1 and 7 terminate and release their memory. The memory block released by Job 1 is enough to hold Job 8. Job 9 has a size of 88 k. no free memory block is large enough to hold Job 9. Job 10 can neither be loaded because Job 9 should be the first one to be loaded.





Relocatable Dynamic Partition

( b) compaction is applied. Compaction means placing all free memory blocks together to form one large block. Jobs 3 and 5 were moved upward. The free memory blocks of sizes 10 k, 15 k, 6 k, and 16 k were compacted forming a memory block of size 47 k. now, Job 7 is loaded to the compacted memory block. There is a remaining memory of size 22 k. 22 k is not enough to hold Job 8.

( c) Jobs 3, 5, and 7 terminate and release their memory. Job 8 is loaded. There is a remaining memory of 50 k.

( d) Job 1 terminates and releases its memory. Job 8 is moved upward. The free memory block size is now 150 k. Job 9 is loaded. There is now a remaining memory of 62 k.

( e) Job 8 terminates, releasing 55 k of memory. The free memory has a size of 117 k. Job 10 is now loaded. There is a remaining memory of 17 k.

Saturday, December 4, 2010

Case Study 3:Time-sharing and Multiprogramming System

          In 1950’s multiprogramming capabilities was developed as a feature of the operating system. Computer multiprogramming is the allocation of a computer system and its resources to more than one concurrent application, job or user. Time-sharing, on the other hand, refers to the concurrent use of a computer by more than one user -- users share the computer's time. Time sharing is synonymous with multi-user. Multi-user is common in internet cafes and the like.
          Time-sharing and multiprogramming systems have good uses but along with these uses are security problems. These problems may later lead to serious issues and threats. One of the most common problems in   time-sharing and multiprogramming system is stealing or copying a user’s file. A person can easily alter or even delete the contents of a certain file without an authorized access or permission from the owner of the file. These files may be important files and would lead to serious problems if changes are made. There are also files that are confidential to the owner and would lead to serious problems if exposed. This act can also be considered as plagiarism. Plagiarism is copying another's work, or borrowing someone else's original ideas and making them yours. For instance, copying the user’s compositions, writings, poems, and others and printing it with your name as the writer. It is an act that is prohibited by the law because that person who stole the file, stole the original ideas of the owner of the file.
Another problem is deleting, changing and installing programs or applications without proper authorization. For instance, in an internet café, you can easily install or delete an application on the computer without the owner or operator knowing it. The user of the computer can also change the contents of some programs. This may cause those programs not to function well. Installing programs to the computer could also be a problem. There is a tendency that the program or application that will be installed might carry viruses that can harm the system. These changes can also affect the other users of the system. It would also be a great burden for the owner to be fixing such problems.
         A dedicated machine is a computer that services one primary function or task. For example, an automobile might have an onboard computer that is dedicated solely to navigation. I can say that dedicated machines are more secured than the time-sharing machines. Base on the definition, a dedicated machine is a machine that is intended to perform a single certain task, thus it ensures that it only performs the tasks that are intended for it. Dedicated machines are also used by only one user. Therefore, using dedicated machines than time-sharing machines is more secure because in dedicated machines, the user or owner is the only person that can access the machine. This helps in preventing security problems like the ones mentioned above. And also in dedicated machines, the user is confident and secured that all his files and all the programs or applications installed in the machine are kept private and unauthorized access will be blocked.

Case Study 2:Hand-held Computers


          A computer is a device that computes, especially a programmable electronic machine that performs high-speed mathematical or logical operations or that assembles, stores, correlates, or otherwise processes information. If we trace the history of computers, we could see that one of the first computers that were used had a size that we could not imagine possible for a computer. As the time pass by, along with the growing knowledge of the human mind, major breakthroughs in the digital world were also made. Discoveries were made known and different devices were created. Computers evolved from what we called the mainframes, these are computers that are made up of thousands of vacuum tubes. Then the 1970’s mini computers which are smaller and are composed only of hundreds of vacuum tubes. After that there was a wide spread use of microprocessors in the 1980’s. And in the 1990’s, hand held devices were widely used throughout the world. What is a hand held computer? Base on the definition from searchmobilecomputing.com, a handheld computer is a computer that can conveniently be stored in a pocket and used while you're holding it. Today's handheld computers, which are also called personal digital assistants (PDAs), can be divided into those that accept handwriting as input and those with small keyboards.

          In communication Arts, Journalism, and Publishing, a newspaper reporter is a person who reports, especially one employed to gather news for a newspaper, news agency, or broadcasting organization. In their type of work, the use of handheld computer would be a really great help to them. One way that a hand held computer can help them is in recording. Newspaper reporters are always on the go to search for any event or happening that would be reporting. They would need to record everything that has happened in that event, and that record would later be edited. A traditional newspaper reporter would use a piece of paper and a pen to write down every detail of the event. It would be a disadvantage because it would take quite a lot of their time and their effort. And there is a tendency that they would miss a part of that event while they are writing. They would also need a place where they could write properly and it would be a disadvantage if they are in a fight scene or a scene that does not have that kind of place. By using hand held computers, newspaper reporters would have an efficient use of their time and effort. Hand held, from the word itself, you can use it with just a hand. They can use a hand held computer to record every detail of the event without even having the need to look at what they are typing on the computer. They would be confident that whatever they typed would still be legible. And unlike the use of pen and paper, they can use the hand held computer without having a proper place to write or record. So they can use it even if they are in a war. Another way that a hand held computer could help a newspaper reporter is in doing research. Their job also requires research. They would need a lot of reference materials just like books and of course, the web. Nowadays, people would say that the web is more reliable than the books. Their reason was because they have seen too many errors in the books, especially in text books which are used by students as a reference material. So, in doing their research, newspaper reporters would need an internet connection. Today, with the use of mobile phones, we can have an internet access. So internet connection is also made handy. Even if a newspaper reporter does not have a personal computer at home, he would not have the need to go to an internet café or a library to use a desktop computer. The only thing that he needs is his mobile phone, of course the modern mobile phones and not those with antennas. So anytime, anywhere ha can do his research.
          A general practitioner doctor is a physician whose practice is not oriented to a specific medical specialty but instead covers a variety of medical problems in patients of all ages. In their type of work, they would be meeting different people with different character. And for some purposes, a doctor would need a record of each of his patient. Every record is written in a piece of paper and is stored in a certain place. The problem with this is that there is a tendency that the record of a patient would get lost. The doctor meets quite a large number of patients so it also means a large number of records. It would be time consuming if the doctor would look for a certain record and go through a huge stack of papers. By using hand held computers, doctors would not go through this problem looking for a single record. They can use hand held computer for their patient’s record. The record of each patient will be stored in a file and will be saved in the computer. So the doctor would not have to worry about loosing a record of his patient. And in searching a record, the doctor would not have the need to go through each of the saved record; all he needs to do is to type the name of his patient and in just an instant, the record would show up. It is what modern technology can do—a handy record book. And just like newspaper reporters, doctors still have the need to do a research. So with the use of a hand held computer, they can do their research in any place they want and in any time.
           In conclusion, hand held computer would be a great help to newspaper reporters and a general practitioner doctor. When used properly, it would make a really great change to the world but when not properly utilized would cause a great destruction to human kind. We must remember that everything has its own advantage and disadvantages.

Tuesday, November 23, 2010

Case Study 1:Types of Operating Systems

Batch Systems: OS/2
OS/2 is a computer operating system, initially created by Microsoft and IBM, then later developed by IBM exclusively. The name stands for "Operating System/2," because it was introduced as part of the same generation change release as IBM's "Personal System/2 (PS/2)" line of second-generation personal computers.
OS/2 is compatible with DOS and Windows, which means that it can run all DOS and Windows programs. However, programs written specifically to run under OS/2 will not run under DOS or Windows.
Any real mode operating system could also be made to run using OS/2's virtual machine capabilities, subject to certain direct hardware access limitations.
Because OS/2 only ran the user-mode system components of Windows, it was not compatible with Windows device drivers (VxDs) and applications needing them.
Multiple Windows applications ran in a single Windows session, just as they would under native Windows. To achieve true isolation between Windows 3.x programs, OS/2 could run multiple copies of Windows in parallel. This approach required considerable system resources, especially memory.


Interactive Systems: UNIX


Unix operating systems are widely used in servers, workstations, and mobile devices. The Unix environment and the client–server program model were essential elements in the development of the Internet and the reshaping of computing as centered in networks rather than in individual computers. Unix was designed to be portable, multi-tasking and multi-user in a time-sharing configuration.

Unix systems are characterized by various concepts:
·         the use of plain text for storing data
 ·         a hierarchical file system
·         treating devices and certain types of inter-process communication(IPC) as files; and
·         the use of a large number of software tools, small programs that can be strung together through a command line interpreter using pipes, as opposed to using a single monolithic program that includes all of the same functionality.
These concepts are collectively known as the Unix philosophy.


Real-time: RT- Linux

RT-Linux is an operating system in which a small real-time kernel coexists with the Posix-like Linux kernel. The intention is to make use of the sophisticated services and highly optimized average case behaviour of a standard time-shared computer system while still permitting real-time functions to operate in a predictable and low-latency environment.


RT-Linux is both spartan and extensible in accord with two, somewhat contradictory design premises.
The first design premise is that the truly time constrained components of a real-time application are not compatible with dynamic resource allocation, complex synchronization, or anything else that introduces either hard to bound delays or significant overhead. The most widely used configuration of RT-Linux offers primitive tasks with only statically allocated memory, no address space protection, a simple fixed priority scheduler with no protection against impossible schedules, hard interrupt disabling and shared memory as the only synchronization primitives between real-time tasks, and a limited range of operations on the FIFO queues connecting real-time tasks to Linux processes. The environment is not really as austere as all that, however, because the rich collection of services provided by the non-real-time kernel are easily accessed by Linux user tasks. Non-real-time components of applications migrate to Linux. One area where we hope to be able to make particular use of this paradigm is in QOS, where it seems reasonable to factor applications into hard real-time components that collect or distribute time sensitive data, and Linux processes or threads that monitor data rates, negotiate for process time, and adjust algorithms.
The second design premise is that little is known about how real-time systems should be organized and the operating system should allow for great flexibility in such things as the characteristics of real-time tasks, communication, and synchronization. The kernel has been designed with replaceable modules wherever practical and the spartan environment described in the previous paragraph is easily "improved" (or "cluttered", depending on one's point of view). There are alternative scheduling modules, some contributed by the user community, to allow for EDF and rate-monotonic scheduling of tasks. There is a "semaphore module" and there is active development of a richer set of system services. Linux makes it possible for these services to be offered by loadable kernel modules so that the fundamental operation of the real-time kernel is run-time (although not real-time) reconfigurable. It is possible to develop a set of tasks under RT-Linux, test a system using a EDF schedule, unload the EDF scheduling module, load a rate monotonic scheduling module, and continue the test. It should eventually be possible to use a memory protected process model, to test different implementations of IPCs, and to otherwise tinker with the system until the right mix of services is found.


Hybrid: Sun386i (codenamed Roadrunner)

The Sun386i was a hybrid UNIX workstation/PC compatible computer system produced by Sun Microsystems, launched in 1988. It was based on the Intel80386 microprocessor but shared many features with the contemporary Sun-3 series systems.
It designed for stand-alone operation or for connection to networks.  It is a multi-user, multi-tasking system but is also capable of running many MS-DOS applications. There are three models - the 150, the 150X and the 250.


Embedded: Windows CE

Known officially as Windows Embedded Compact or Windows Embedded CE is an operating system developed by Microsoft for minimalistic computers and embedded systems. Windows CE is a distinct operating system and kernel, rather than a trimmed-down version of desktop Windows.
Windows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of memory. It has evolved into a component-based, embedded, real-time operating system.  It is no longer targeted solely at hand-held computers.
A distinctive feature of Windows CE compared to other Microsoft operating systems is that large parts of it are offered in source code form. First, source code was offered to several vendors, so they could adjust it to their hardware. Then products like Platform Builder (an integrated environment for Windows CE OS image creation and integration, or customized operating system designs based on CE) offered several components in source code form to the general public. However, a number of core components that do not need adaptation to specific hardware environments (other than the CPU family) are still distributed in binary only form.