Hill climbing is an optimization algorithm that belongs to the family of local search methods. It is often used in artificial intelligence and computer science to find a solution to problems by iteratively making incremental changes to a solution and selecting the best one available. The process can be thought of as climbing a hill: the algorithm starts at a given point (a solution) and explores neighboring points (solutions) in the solution space.

Platform screen doors (PSDs) are barriers installed at train or subway stations that separate the platform from the tracks. They are designed to enhance safety and improve passenger experience by preventing accidents on the tracks, such as falls or unauthorized access, as well as to reduce the impact of noise and improve climate control within stations.

"Presumed security" is a concept that refers to the assumption that certain systems, protocols, or environments are secure by default, often due to their design, reputation, or the ways in which they have been implemented. This presumption can lead users and organizations to believe that they do not need to take additional precautions or to scrutinize the security measures in place, potentially leading to vulnerabilities if the underlying assumptions turn out to be incorrect.

The number 128 is an integer that follows 127 and precedes 129. It has several interesting properties: 1. **Mathematical Properties**: - It is a power of two: \( 128 = 2^7 \). - It is an even number. - The divisors of 128 are 1, 2, 4, 8, 16, 32, 64, and 128.

Late Move Reductions (LMR) is a technique used in computer chess and other game-playing AI to optimize the search process in game trees. The idea behind LMR is to skip certain moves that are unlikely to change the outcome of the search based on previous evaluations, thus allowing the algorithm to focus its computational resources on more promising moves.

Lifelong Planning A* (LPA*) is an extension of the A* search algorithm that is designed to efficiently plan over an extended horizon, particularly in dynamic environments where changes can occur during the planning process. The key features of LPA* include: 1. **Incremental Replanning**: Unlike traditional A*, which recalculates paths from scratch, LPA* updates existing paths based on changes in the environment.

Linear hashing is a dynamic hashing scheme used for efficient data storage and retrieval in databases and file systems. It is designed to handle the growing and shrinking of data in a way that minimizes the need for reorganization of the hash table. ### Key Features of Linear Hashing: 1. **Dynamic Growth**: Linear hashing allows for the hash table to expand and contract dynamically as data is added or removed. This is particularly useful for applications with unpredictable data volumes.

Locality-Sensitive Hashing (LSH) is a technique used to effectively and efficiently retrieve similar items from large datasets. It's particularly useful in applications involving high-dimensional data, such as image retrieval, text similarity, or near-neighbor search.

Look-ahead and backtracking are concepts often associated with algorithm design and problem-solving techniques, particularly in the context of search algorithms. ### Look-ahead: Look-ahead is a strategy used to anticipate the consequences of decisions before committing to them. It involves evaluating several possible future states of a system or a decision path to see what outcomes can arise from various choices.

In the context of game theory, specifically when analyzing game trees, "variation" refers to the different possible sequences of moves or play that can occur in a game. Each variation represents a unique path through the game tree, which is a visual representation of the possible moves in a game from the initial state to all potential outcomes. ### Key Concepts: 1. **Game Tree**: A game tree is a branching diagram that illustrates the sequential moves in a game.

Proactive secret sharing is an advanced cryptographic technique designed to enhance the security and reliability of secret sharing schemes. In traditional secret sharing, a secret (such as a cryptographic key) is divided into multiple shares and distributed among participants, where a certain threshold of these shares is required to reconstruct the secret. While effective, traditional schemes can be vulnerable to certain attacks, such as when a participant's share is compromised or when all shares are static over time.

3D security, in the context of digital transactions, often refers to "3-D Secure," a security protocol designed to enhance the security of online credit and debit card transactions. The protocol aims to reduce fraud and provide a safer online shopping experience by adding an additional layer of authentication during the payment process.

NewsRx is a news service that specializes in delivering information and updates related to various fields, including health, medicine, pharmaceuticals, biotechnology, and other scientific sectors. The platform aggregates and disseminates news articles, press releases, and research findings from a wide range of sources, catering to professionals, researchers, and organizations interested in the latest developments in these areas. NewsRx often provides insights into clinical trials, regulatory changes, and emerging trends in the industry, helping its audience stay informed about crucial developments.

The Null-move heuristic is an optimization technique used in search algorithms, particularly in game tree search applications like those found in chess and other strategy games. Its primary purpose is to reduce the number of nodes evaluated during the search process by skipping certain moves and using the result to prune the search tree effectively.

A **perfect hash function** is a type of hash function that maps a set of keys to unique indices in a hash table without any collisions. This means that each key in the set corresponds to a unique index, allowing for fast retrieval of the associated value with no risk of overlapping positions. Perfect hashing is particularly important in scenarios where the set of keys is static and known in advance. ### Types of Perfect Hash Functions 1.

Phrase search is a search technique used in information retrieval systems, such as search engines and databases, to find results that match an exact sequence of words or phrases. When using phrase search, the searcher typically places quotation marks around the desired phrase. For example, searching for "climate change" would return results that contain that exact phrase rather than results that only contain the individual words "climate" and "change" in different contexts.

A **Range Minimum Query (RMQ)** is a type of query that seeks the minimum value in a specific range of a sequence or array. This is a common problem in computer science and has applications in areas such as data processing, optimization, and computational geometry.

The Rocchio algorithm is a classic method used in information retrieval and text classification. It was originally developed for relevance feedback in document retrieval systems. The algorithm helps to improve the relevance of search results by re-evaluating document vectors based on user feedback. Here's a more detailed breakdown of its key components and functionality: ### Key Concepts: 1. **Vector Space Model**: Documents and queries are represented as vectors in a high-dimensional space.

A search algorithm is a method used to retrieve information stored within some data structure or to find a specific solution to a problem. It involves systematically exploring a collection of possibilities to locate a desired outcome. Search algorithms are fundamental in computer science and are used in various applications, such as databases, artificial intelligence, and optimization. There are two primary categories of search algorithms: 1. **Uninformed Search Algorithms**: These algorithms do not have additional information about the problem apart from the problem definition.

The term "Search Game" can refer to a couple of concepts depending on the context: 1. **Computer Science and Artificial Intelligence**: In the realm of algorithms, particularly in artificial intelligence (AI) and computer programming, a "search game" can refer to problems involving searching through a space (like a game tree or state space) to find an optimal solution.