Artificial Intelligence: Video Games

Can you think of a game without an AI or computer controlled opponent? I certainly can't! One of the most interesting fields of Computer Science is Artificial Intelligence, or known as AI.  There are many applications for AI such as speech recognition (like Siri on iPhone), natural language processing, computer vision, etc.  However, I find games are some of the more interesting applications that utilize AI.  Well what is AI in games? They are techniques used to produce the illusion of intelligence in the behavior of non-player characters.  You could have competent opponents or helpful allies!

How it is implemented depends on the type of game, such as RTS (Real-time strategy), FPS (First-Person shooter), RPGs, sport games, etc.  Here are some common elements in which AI are implemented:

• Event Driven Engine: AI reacts based on events.
• Specific AI Structure: how the AI moves and determines reasoning and its behavior.
• Path-Finding: finding the shortest path to a certain destination.
• Animation sequences for different body parts such as shooting/reloading in FPS.
• Scripted Behavior: show their personality through dialogue, contributing to the overall storyline of the game.
• Collision: detect obstacles in game.

As an SJSU student, I have yet to learn about the algorithms used in video games to create AI. The most popular algorithms used are A(*),  Finite State machines, and Artificial Neural Networks.  Every game you've played has definitely used some sort of AI, and have implemented these algorithms.  

History of Computer Science: Mobile Application Development

How long ago do you think Apple released the Itunes App Store? Only five years, but it feels like ten years to me! In just five years, smartphones have become ubiquitous as well as its mobile applications. These mobile applications have now become a great part of our daily lives. The birth of the Itunes App Store in 2008 led to the creation of the millions of apps that we have today.  What apps you may ask? Well, a well-designed app has the potential to help increase productivity and even revolutionize the job market.

The history of mobile application development actually dates back to 2003, introduced first by IBM. It was not popular back then and only had basic features.  However, a later major advancement arrived in 2002, when the Blackberry-smartphone was introduced.  Thus began wireless emailing.  As time went on, new mobile platforms(iOS and android) were introduced which further boosted mobile app development.  With these smartphones, mobile technology became completely revolutionized.  Mobile apps have allowed people to become more efficient and allow new experiences.  For me, I have used the Udemy app which allows me to take a course anywhere, without the need for laptop or desktop.

File Sharing: Client-Server Downloading vs. P2P Sharing

I’m sure you have downloaded something off the web but do you know the process?  When you download something, your computer, the client, tells the server (computer that holds the web page and file) to transfer a copy of the file to your computer.  This transfer goes through a protocol, or set of rules. The transfer speed is affected by the type of protocol (FTP or HTTP), amount of traffic on server, and number of other users downloading the file.  How does this traditional client-server download contrast with peer-to-peer sharing?

In peer-to-peer sharing, you use a software program, such as BitTorrent.  BitTorrent downloads torrents, which are files that point to the computer with the desired file. BitTorrent sends a request for the file by communicating with a tracker (central server with the file) to locate other computers connected to the internet.  The tracker finds a swarm, or a group of connected computers that are file sharing.  Once BitTorrent finds a seeder, or a computer that has the complete file, it will start downloading the file.   Basically, you are downloading small bits of files from different sources at the same time.   Once you finish downloading, you will become a seeder and help others download the file. 

BitTorrent is sometimes used for distributing copyrighted material but the program is still legal.  If you choose to download any copyrighted material, you are at risk of being caught, since the download can be traced back to you.  Be careful and happy downloading!

Data Structures: Real World Applications

If you’re a CS major, I am sure you have come across a data structure.  You may have worked with arrays, linked lists, graphs, or trees.  These are all ways of storing and organizing data for efficient usage. There is no “best” data structure and are used depending on the task at hand; all data structures have pros/cons.  The question is HOW are these structures used in the real world? Let’s take a look at a few common ones:

1) Linked List

An example on how a linked list may be used in the real world is managing a train.  These trains are linked together in a calculated way so that items can be loaded, transferred, unloaded, and picked up efficiently.  Like a linked list, trains can be added or removed at any point of the train.  Also, the train at the end can be removed easier than the train in the middle.  Therefore, one may use a linked list in order to plan the order of the trains, and the contents of the trains.  

2) Binary Search Trees

Binary Search Trees are often used for data that is constantly added or removed, such as a map or set of objects.  For example, any language library (C++, Java, .Net, etc) uses binary search to find items; items are inserted in order, and items can be easily accessed.  

3) Hash Tables 

Internet Routers use Hash Tables; a router table may contain millions of entries.  Therefore, the router must determine the best route by querying the router table when the packet is routed to a specific IP address.  In this case, the key is the IP address and the value is the address.

Knowing when to implement these data structures is important because some are more efficient, depending on the task!

Hacking: iOS Jailbreaking

Jailbreaking is the legal process of bypassing restrictions on Apple devices (iPhone, iPad, iPod Touch) running the iOS system. If you want to know how it exactly works, an explanation on how the evasi0n jailbreak works is shown here. 

Essentially, what happens is a modified set of kernel patches is installed. The kernel is the supervisor of the OS and allows you to run unsigned code.  When you jailbreak, you’re able to use unauthorized software and download tweaks.  However, there is a reason why Apple made the iOS to be a closed environment! Let’s go over some pros/cons. 

Pros

• New apps. Apps like Cydia allow you to install apps that are not in the Itunes App Store.
• Customization.  Winterboard allows you to change your icons and wallpaper, customize sounds, etc.
• Secure Shell Client (SSH).  You can manage all of your iPhone’s files. 

Cons

• No security and limited antivirus protection. You never know if the unauthorized app you are downloading contains malware.
• Instable; can brick your phone and render it useless.
• No warranty. 

If you decide to jailbreak your phone, do it at your own risk! If you are careful in what you download, you can maximize the true potential of your device.  I have jailbroken my iphone (iOS 6) and have downloaded some useful apps myself.  TheiOS 7 jailbreak is not released yet so sit tight.  If you do happen to jailbreak your phone, check out these.

1. Nitrous: significantly speeds up web browsing on mobile device
2. BiteSMS: quicker way to compose/reply to messages.
3. MapsOpener: forces map links to open in Google Maps instead of stock Apple Maps app.  

For me, jailbreaking my iphone has allowed me to take advantage of unauthorized but useful apps.  I highly recommend anybody to jailbreak to make the best use of the device.  Just remember to be careful!

Open Source: Free Tools

Everything comes with a price. Except free open source software! Open source refers to something that can be modified because its design is publicly accessed.  Therefore, open source software is software whose source code is available for modification by anyone. You may have heard of Firefox, Thunderbird, Open Office, BitTorent, VLC Media Player, Audacity, etc.  These are all FREE tools that everyone should take advantage of! Here is my favorite open source software list:

1) Open Office: This is a great alternative to Microsoft Office that handles most of Microsoft Office's productivity tasks from document production to creating full multi-media presentations.

2) VLC Media Player: very simple and powerful media player since it can play most codecs  (MPEG-2, DivX, H.254, MKV, WebM, WMW, MP3..)., plays everything (files, discs, webcams...) and runs on all platforms (Windows, Linux, Mac OS X...).

3) Audacity: a multiplatform audio edittor that can import and export in numerous formats (WAV, FLAC, AU...). It is useful for anyone that needs to manipulate audio.

Of course there's benefits of being a consumer of these tools but what about on the developing side?
Public collaboration.  Most open source projects, like Wordpress,  are created by a large number of programmers, all working together to create a software package.  Also, because it's open source, source code is available to ALL developers that want to contribute.

Go take advantage of these free tools!

Agile: Understanding Agile Methodology

      When I first heard of agile in my CS100W class, I was thinking of the actual definition: Characterized by quickness, lightness, and ease of movement.  I continued to learn that the term "agile" in class refers to a software development method! You may have heard of other software development methods such as Waterfall, Spiral, Iterative and Incremental, etc. These are all methods that work as a framework which controls project development and maintenance.  Agile Methodology is an alternative to traditional project management, based on iterative and incremental development. Requirements and solutions through cooperation between self-organizing, cross-functional teams.

Here are some underlying principles of Agile Methodology:

1) Complex projects are broken into smaller, attainable goals.

2) Simplicity

3) Face to face communication (the best kind of communication!)

4) Close, daily cooperation between business people and developers

5) Regular adaption to changing circumstances

A framework that uses agile methodology is Scrum.  Projects are broken down into smaller pieces that are managed and completed in short intervals called sprints.  These sprints, which are often two to four weeks, involve short term goals that are part of the main goal.  Following the process above, customers receive the "Release" often and are able to evaluate it so that modifications can be made.

Agile is a very powerful tool that can be used efficiently in any project. Although it may not be the best option, it provides a productive approach for teams and product development.