Search Results

In this chapter we cover competitive environments, in which two or more agents have conflicting goals, giving rise to adversarial search problems. We consider games with two players turn-taking zero sum perfect information deterministic and stochastic (they c...

MAX wants to find a sequence of actions leading to a win, but MIN has something to say about it. This means that MAX’s strategy must be a conditional plan—a contingent strategy specifying a response to each of MIN’s possible moves. Given a game tree, the opti...

Reduces the complexity of the minimax search by not considering branches of the game tree that cannot influence the final decision Alpha-beta pruning returns the same outcome of the “vanilla” minimax search. Two parameters: $\alpha$: It represents the value o...

The basic MCTS strategy does not use a heuristic evaluation function. Instead, the value of a state is estimated as the average utility over a number of simulations of complete games starting from the state. A simulation (also called a playout or rollout) choo...

Many games include unpredictable stochastic events, like throwing of dice in backgammon We can apply an approach like minimax search using a game tree with chance nodes and expectiminimax values Alpha-beta pruning can be applied to stochastic games

Factored representation for each state: a set of variables, each of which has a value. A problem is solved when each variable has a value that satisfies all the constraints on the variable. A problem described this way is called a constraint satisfaction probl...

A CSP algorithm has choices. It can generate successors by choosing a new variable assignment, or it can do a specific type of inference called constraint propagation: using the constraints to reduce the number of legal values for a variable, which in turn can...

Sometimes we can finish the constraint propagation process and still have variables with multiple possible values. In that case we have to search for a solution. CSP is commutative: the order of application of any given set of actions does not matter. We need ...

A logical agent is an agent that is capable of using logical sentences to represent knowledge of states and actions, and to exploit such representation to decide what to do By logical sentence we mean a sentence (i.e., a well-formed formula) of the formal lang...

Syntax The syntax of propositional logic defines the allowable sentences. The atomic sentences consist of a single proposition symbol. Each such symbol stands for a proposition that can be true or false. We use symbols that start with an uppercase letter and m...

Our goal now is to decide whether $KB \models \alpha$ for some sentence $\alpha$. Reasoning with truth tables Reasoning with truth tables is a form of semantic reasoning, in the sense that it directly exploits the definition of entailment: 𝛼 ⊨ 𝛽 holds when 𝛽 i...

Software platform to easily process vast amounts of data. The main features are: Scalable: It can reliably store and process petabytes. Economical: It distributes the data and processing across clusters of commonly available computers (in thousands). Effic...

HDFS Architecture NameNode Manages File System Namespace Maps a file name to a set of blocks Maps a block to the DataNodes where it resides Cluster Configuration Management Replication Engine for Blocks: NameNode detects DataNode failures Chooses new Dat...

Shell Commands There are two types of shell commands: User Commands hdfs dfs – runs filesystem commands on the HDFS hdfs fsck – runs a HDFS filesystem checking command Administration Commands hdfs dfsadmin – runs HDFS administration commands The g...

YARN Splits up the two major functions of JobTracker Global Resource Manager - Cluster resource management Application Master - Job scheduling and monitoring (one per application). The Application Master negotiates resource containers from the Scheduler,...

Introduction MapReduce is a programming model and an associated implementation for processing and generating big data sets with a parallel, distributed algorithm on a cluster. A MapReduce program is composed of a map procedure, which performs filtering and s...

Input Splitter Is responsible for splitting your input into multiple chunks (default is 64MB). These chunks are then used as input for your mappers Splits on logical boundaries. Typically, you can just use one of the built in splitters, unless you are reading ...

By default, Hadoop uses FIFO to schedule jobs. Alternate scheduler options: capacity and fair Capacity Scheduler Jobs are submitted to queues Jobs can be prioritized Queues are allocated a fraction of the total resource capacity Free resources are allocated t...

HBase is a key-valued row/column store modeled on Google’s Bigtable providing Bigtable-like capabilities for Hadoop. That is, it provides a fault-tolerant way of storing large quantities of sparse data (small amounts of information caught within a large collec...

Apache Pig is a high-level platform for creating programs that run on Apache Hadoop. The language for this platform is called Pig Latin. Pig can execute its Hadoop jobs. Pig Latin abstracts the programming from the Java MapReduce idiom into a notation which ma...