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Messages - mnsalim

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Hal Burch conducted an analysis over spring break of 1999 and made an amazing discovery: there are only 16 types of programming contest problems! Furthermore, the top several comprise almost 80% of the problems seen at the IOI. Here they are:
Dynamic Programming
Complete Search
Flood Fill
Shortest Path
Recursive Search Techniques
Minimum Spanning Tree
Computational Geometry
Network Flow
Eulerian Path
Two-Dimensional Convex Hull
Heuristic Search
Approximate Search
Ad Hoc Problems
The most challenging problems are Combination Problems which involve a loop (combinations, subsets, etc.) around one of the above algorithms - or even a loop of one algorithm with another inside it. These seem extraordinarily tricky to get right, even though conceptually they are ``obvious''.

Very useful post. Hope to try all the apps. Thanks for sharing with us :)

Graphics has been developed and will be the new domain of visualizations :)

Really. Now it's with racism. AI has gone so far :(

Common Forum/Request/Suggestions / Re: How to e-mail easily
« on: April 20, 2017, 06:24:35 PM »
Nice :)

AI is the best. The future is full of AI. Thanks for sharing :)

Wow. Interesting. Let's see what's happened in future. :)

« on: April 20, 2017, 05:39:04 PM »
Competitive programming is similar to quiz contests. Here a team or individual is given a number of mathematical and logical problems to solve using any programming language allowed by the host. The competition can span from just a few hours to even months. The categories of problems cover many mathematical concepts like data structures, graphs, number theory, dynamic programming, string processing, algebra, geometry and much more. The competitions take place online – on both local and global networks. The team that solves the most problems earliest with the least erroneous submissions wins. There can also be other criteria of point distribution such as the efficiency of the algorithm, size of the code and many more.

Wow. HumCom: HumanComputer :P

Common Forum/Request/Suggestions / Re: Robot awakening
« on: April 20, 2017, 04:43:49 PM »
AI is the ultimate things and Robotics now is an extended field of AI. The post is really informative. :)

Use of email / Email Security
« on: April 20, 2017, 03:59:01 PM »
The most important point in Email Security is protecting your email login details and messages. This is very important because of the security risks during data transmission, especially on mobile and wireless networks. For this purpose it is recommended to use encryption when checking / sending emails. This can be accomplished by using:

Secure IMAP (IMAPs) - It is used for encrypting the incoming communication from the remote mail server. Check these instructions on how to enable it on Outlook, Outlook Express, Thunderbird and Mac Mail.

Secure POP3 (POP3s) - It is also used for encrypting the incoming communication from the remote mail server. Check these instructions on how to enable it on Outlook, Outlook Express, Thunderbird and Mac Mail.

Note: The difference between IMAPs and POP3s is the same as for the standard IMAP and POP3 protocols. IMAPs leaves the messages on the server. It is faster because it does not download the whole message but only its headers. Furthermore, it is preferred in terms of reliability. When your local computer crashes your mails will not be lost if you have used IMAPs. On the other hand, POP3s downloads the whole message and stores it locally. That's why it is slower and less reliable.

Secure SMTP (SMTPs) - It encrypts the outgoing communication to the remote mail server. Check these instructions on how to enable it on Outlook, Outlook Express, Thunderbird and Mac Mail.

Secure HTTP (secure HTTPs) - It is suitable for checking your webmail. Usually it is available at an URL similar to

The next thing to know about Email Security is how to fight SPAM (unsolicited email) and viruses. Below are some tips on this matter:

Make sure to have an updated antivirus program. We recommend Norton Internet Security which has built-in Spam and Anti-Virus protection.
Update your email client to the latest version. If you have troubles updating your current email client, try the freely available Thunderbird. Many viruses are targeted against outdated mail clients.
Do not open suspicious attachments even if the sender might look familiar.
Avoid subscribing to free newsletters, lotteries or other similar activities. This usually results in an increased number of spam messages in your inbox.
Protect your domain from being spoofed by spammers using an SPF record. Email spoofing will make you receive bounced back messages you have not sent.
Use the SiteGround SpamExperts solution which will protect your e-mail accounts against Spam.

Use of email / Using An Email Alias to Receive Student Work
« on: April 20, 2017, 03:57:56 PM »
Have you ever asked students to email their work to you and all it does is create a big mess in your inbox?  If you don't use a Learning Management System, then one way to organize incoming assignments is to use an email alias.  Both Gmail and Hotmail have this capability.

Gmail Users
Here's a synopsis from the Gmail help page:  "Gmail doesn't offer traditional aliases, but you can receive messages sent to You can set up filters to automatically direct these messages to Trash, apply a label or star, skip the inbox, or forward to another email account."

For teachers, this means you can filter student emails by period.  For example, your Period 1 students can send their work to while your Period 2 students can send their work to msjosiebruin+period

You can use up to 30 Gmail aliases, so use them wisely.

If you don't know how to create a filter, visit this Gmail Help Page.

Hotmail Users
One nice feature of using a Hotmail alias is that your alias can be vastly different from your username.  Maybe your email address is, but your alias is ""  You can send out email using your alias without ever giving away your real email address.  You also can't log into Hotmail with your alias, so that can be an additional layer of security for some.

Hotmail allows a total of 15 email aliases, but you are limited to creating only 5 per year.  To get started on creating a Hotmail alias, click

Control Cyber security Risks / Category of Technical Cyber Crime
« on: April 20, 2017, 03:54:11 PM »
Unauthorized access:
 Some body can do access in to the computer systems or Networks activity for which he is not authorized to do so. This  is commonly known  as hack
Theft of information contained in electronic form:
 By this crime, some body gets access in to the  computer  systems or Networks activity  of another person. Then he collects information stored in computer hard disks and removes the information. This is called Theft of information contained in electronic form.

E-mail bombing:
E-mail bombing occurs when a large number of emails sent to the victim’s computer. As a consequence the victim’s email account or mail servers might crash.

Data diddling:
This kind of  attack involves altering the raw data just before it is processed by a computer and then changing it back after the processing is completed

Salami attacks:
 Salami attack is one kind of financial crime. Here the computer program is altered. The alteration is so insignificant  that in a single case it remains completely unnoticed e.g. A bank employee inserts a program into bank’s servers that deducts a small amount from the account of every customer.

Denial of service Attack :
The computer resource receives so many requests which it can not handle . This crashes the computer resource. As a result the computer resource denies giving proper service to the authorized users. Another kind of denial of service  attack is known as Distributed
Denial of  Service(DDOS) attack. Here the perpetrators are many. They are geographically widespread.

Virus attack: v
iruses are one kind of  programs that attach themselves to a computer or a computer  file and then they  circulate themselves to other files and to other computers on a network . They usually affect the data on a computer either by altering or deleting it.

Worms attack:
Worms are  unlike viruses. It  does not need the host to attach them. They make functional  copies of themselves. They do this repeatedly  till they eat up all the available space on a computer’s memory.

Logic bombs:
These are event dependent programs. These programs are created to do something only when a certain event occurs. Some viruses may be termed logic bombs because they lie dormant all through the year and become active only on a particular date(Like Chernobyl virus).

Trojan attack :
It is an unauthorized program which functions from inside of a computer. It  conceals what  it is actually doing .There are many simple ways of installing a Trojan in someone’s  computer.

Internet Time Theft:
 It is a kind of cyber crime. Here an unauthorized person uses internet hours but payment made by another person. It is a theft of internet hours by using log in name & password from various places causing wrongful loss of internet hour of other users.

Web jacking :
It  occurs when someone forcefully takes control of a website by cracking the password. After that he changes it. The actual owner of the website does not have any more control over  his website. He does not know what appears on that website.

Theft of computer system: It is a kind of offence which involves the theft of a computer, some parts of computer or a peripheral attachment  to the computer.

Physically  damaging a computer system: It is a crime that  is committed by physically damaging a computer or its peripherals.

Control Cyber security Risks / COUNTERMEASURES OF CYBER CRIME
« on: April 20, 2017, 03:50:16 PM »
Due to above mentioned consequences cyber security should be maintained. There are a variety of different technical countermeasures that can be deployed to thwart cyber criminals and harden system against attack. Firewalls, network or host based are considered the first line of defense in securing a computer network by setting Access Control Lists (ACLs) determining which what services and traffic can pass through the check point.

Antivirus can be used to prevent  propagation of malicious code. Most computer viruses have similar characteristics which allow for signature based detection. Heuristics such as file analysis and file emulation are also used to identify and remove malicious programs. Virus definitions should be regularly updated in addition to applying operating system hotfixes, service packs and patches to keep computers on a network secure.

Cryptography techniques can be employed to encrypt information using an algorithm commonly called a cipher to mask information in storage or transit. Tunneling for example will take a payload protocol such as Internet Protocol (IP) and encapsulate it in an encrypted delivery protocol over a Virtual Private Network (VPN), Secure Sockets Layer (SSL), Transport Layer Security (TLS), Layer 2 Tunneling protocol (L2TP), Point  to Point Tunneling Protocol (PPTP) or Internet Protocol Security (IPSec) to ensure data security during transmission. Encryption can also be employed on the file level using encryption protocols like Data Encryption Standard (DES), Triple Data Encryption Algorithm (3DES) or Advanced Encryption Standard (AES) to ensure security of information in storage.

Additionally, network vulnerability testing performed by technicians or automated programs can be used to test on a full-scale or targeted specifically to devices, systems and passwords used on a network to assess their degree of secureness.  Furthermore network monitoring tools can be used to detect intrusions or suspicious traffic on both large and small networks.

Physical deterrents such as locks, card access keys or biometric devices can be used to prevent criminals from gaining physical access to a machine on a network. Strong password protection both for access to a computer system and the computer’s BIOS are also effective countermeasures to against cyber criminals with physical access to a machine.
 The threat is advancing quicker than we can keep up with it. The threat changes faster than our idea of the risk. It’s no longer possible to write a large white paper about a risk of a particular system. So according to the nature of threat we  have to  take the decision. By maintaining the proper security we can not say that the system is fully secured. So the system can compromise,  in that case we need cyber expert & cyber forensic lab that can help to detect the cyber criminals and to ensure punishment  accordingly by  cyber laws.

Targeting to make a digital Bangladesh by 2021, we have already stepped into the digital era. Lives will be much easier, quicker & meaningful if we use the digital facilities to perform our day to day activities. Once, people did not feel satisfied if a printed newspaper was not at their hands in the morning. Today, the same people feel nasty if the internet is disconnected. It is very easy to think that we will be in a digital Bangladesh in few years. But very few people imagine that the digitalization without proper security measures will make our lives hell overnight.

On 23 August 2004 an email was sent to the Daily prothom- Alo threatening to kill Sheikh Hasina,  the leader of the opposition in the parliament. Two days later on 25 August, 2004 another email was sent to the Bangladesh Police Headquarters, threatening Khaleda Zia, the Prime minister, her elder son and some members of the parliament. These were the first cyber crime incidents in Bangladesh which received due attention of the police authority.

The Prime minister inaugurated the opening of 64 district web portals on 6 January, 2010 while the hackers  invaded 19 of them by 21 March, 2010. This was the first cyber criminality by the foreign hackers. However, the news of cyber crime is sporadically published in the newspapers at interval. But like the traditional ones most of the computer related crimes remain unpublished, unregistered and uninvestigated.

The computer and the internet system have opened not only wide avenues for the development and humanitarian activities across the world, but they have also ushered in a vast world for the criminal section of the society. Unlike the traditional criminals, cyber criminals are sufficiently educated & highly specialized in computer systems and networking. They possess good IQs too. They can crack into your bank account rendering it empty, steal your valuable information and data from your computers and sell them to your enemies to defeat you in your business and even in your war planning. The terrorist organizations are the beneficiaries of the internet communication system. From disseminating motivated information to the innocent public to credit card fraud, the terrorist organizations may use the internet system in their benefits. Many of the terrorist organizations maintain their own web sites. Most communications of the AL Queda networks are performed through the internet. Even the Bangladeshi terrorist organization JMB does not go less. Although their own web site is still unknown, they have developed internet specialization among their operators. The intensity of cyber crime victimization in Bangladesh is yet to be measured. There are no research or data collection efforts on how much money is lost every year due to cyber criminality. Neither the government nor the non government organizations have initiated any data collecting project about it. But many countries of the world collect & preserve statistics on cyber crime and the monetary loss due to cyber criminality across & outside of their countries. Many countries have been adopting innovative measures to detect and investigate the cyber crime. Almost every country has developed  Computer Emergency Response Team(CERT). The Malaysian developed  Computer Emergency Response Team(MyCERT) which operates the Cyber999 help centre, a public service that provides emergency response to computer security related emergencies as well as assistance in handling incidents such as computer abuses, hack attempts & other information security breaches.
The Chinese government has taken the innovative techniques to fight cyber crimes. Their measures are simultaneously preventive, investigative & preoperative. According to  reports from Chinese media ,two virtual police officers –one male, one female will appear at the bottom of user’s browser windows every thirty minutes, a visual reminder that they are being monitored. Many police agencies across the world set up special cyber crime units to fight the cyber crimes. Virtual police stations are common in many countries. Even our neighboring state, west Bengal started the function of cyber police station.

Cyber crime is still a low priority in Bangladesh. As a whole Bangladesh is not aware of her cyber security. Though computers are becoming  common house hold items and the number of internet users have already crossed thirty millions, very few computer related offences are reported to the police. In Bangladesh there is no Computer Emergency Response Team(CERT), no cyber police or virtual police to handle the incidents such as computer abuses, hack attempts and other information security breaches. It is known that there is a cyber crime unit in CID headed by a DIG. Some officers were given  special training on the purpose but for the want of necessary logistic support the unit remains nonfunctional. They have been dealing with cell phone related petty crimes only. The legal provisions to deter the cyber criminals from doing harm to billions of dollars are not sufficient. Bangladesh has enacted the Information and Communication Technology ACT-2006 with a maximum punishment for the cyber crime up to ten years of imprisonment or maximum fine of one crore taka or with the both. But the legislation may not be sufficient to effectively fight cyber crimes, For the offences under the act are non cognizable i.e the police can not arrest the alleged offender without the warrant of arrest. The non cognizance of an offence gives the perpetrators an upper hand over the victims. To fight cybercrime we must not impose all liabilities to the government. Computer and Internet system have facilitated the non government organizations a lot. They should have the largest interest in cyber security. So non government organizations must come forward to augmenting the governmental initiatives with money, logistics and specialized manpower. Mumbai  Cyber Lab is a unique initiative of public-private collaboration  in investigation of cyber crime. Bangladesh should follow their suit. The government should  welcome outsourcing initiatives to prepare a galaxy of virtual police officers and establish  few cyber police stations across the country as soon as possible. These cyber crime fighters should be given specialized training home and abroad. Introduction of cyber crime tribunals should be done at least in divisional headquarters of Bangladesh as early as poss

The present government is expected to invest millions of taka to materialize their promise to build a digital Bangladesh. So the issue of cyber security must get a  due priority and a considerable portion of budget should be allocated to ensure the cyber security. There is no denying that cyber criminals are very much capable of robbing Bangladesh causing the loss  of crores of taka. They can make a havoc in our national life at any time. At that time we will find that our stallions are stolen and we will then be very much careful to lock our empty stables. So, let us prepare for the worst beforehand. Prevention is undoubtedly better than cure. 

Control Cyber security Risks / Effects of Cybercrimes
« on: April 20, 2017, 03:49:26 PM »
Effects of Cybercrimes:
Cyber crime affects more than the financial integrity of a business. There are many real and damaging consequences associated with internet crime. The losses are various types, Li

Loss o
f Revenue:-One of the main effects of cyber crime on a company is a loss of revenue. This loss can be caused by an outside party who obtains sensitive financial information, using it to withdraw funds from an organization. It can also occur when a business's e-commerce site becomes compromised while inoperable, valuable income is lost when consumers are unable to use the site.

Wasted time:- Another major effect or consequence of cyber crime is the time that is wasted when  IT Personnel must devote great portions of their day handling such incidences. Rather than working on productive measures for an organization, many IT staff members spend a large percentage of their time handling security breaches and other problems associated with cyber crime.

Damaged Reputations:-In cases where customer records are compromised by a security breach associated with cyber crime, a company's reputation can take a major hit. Customers whose credit cards or other financial data become intercepted by hackers or others infiltrators lose confidence in an organization and often begin taking their business elsewhere. 

Reduced Productivity:-Due  to the  measures that  many companies must implement to counteract cyber crime, there is often a negative effect on employee's productivity. This is because, due to security measures, employees must enter more password and perform other time consuming acts in order to do their jobs. Every second wasted performing these tasks is a second not spent working in a productive manner.

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