• 디지털융복합연구
• /
• 제14권8호
• /
• pp.415-421
• /
• 2016

행동 트리는 인공지능의 행동을 표현하는 트리로 FSM(Finite State Machine)보다 상태 전이가 용이하고 행동의 진행을 쉽게 알 수 있는 특징을 갖고 있다. 때문에 최근 FSM보다 널리 쓰이고 있는 추세이다. 본 논문은 이러한 배경에서 게임 엔진의 행동 트리의 장단점을 분석하고 이를 바탕으로 개선된 행동 트리를 제안하기 위한 것이다. 이를 위해 본 논문에서는 첫째, 유니티 엔진과 언리얼 엔진의 행동 트리 구조와 노드들의 역할을 먼저 살펴본다. 둘째, 살펴본 행동 트리의 구조와 노드들을 바탕으로 장점과 단점을 논한다. 셋째, 이 행동 트리들의 단점인 트리의 깊이와 실행 노드 검색 시간을 개선한 행동 트리를 제안한다. 본 논문은 추후 행동 트리를 사용해 게임 개발을 하려는 개발자들에게 도움을 줄 수 있다.

• 한국컴퓨터정보학회:학술대회논문집
• /
• 한국컴퓨터정보학회 2016년도 제53차 동계학술대회논문집 24권1호
• /
• pp.267-269
• /
• 2016

본 논문에서는 언리얼 엔진4의 Behavior Tree(행동 트리)를 이용하여 NPC의 다양한 상태와 움직임을 가진 어드벤처 게임 AI를 설계 및 개발하였고, 그 효율성을 분석하였다. Behavior Tree는 상태와 행동을 계층적으로 나누어 AI의 행동을 결정하는 알고리즘으로 FSM(Finite State Machine, 유한상태기계)과 비교하여 유지보수와 행동 규칙 검증의 어려움을 해결하는 데 장점이 있음을 확인하였다.

• 한국멀티미디어학회논문지
• /
• 제25권2호
• /
• pp.432-439
• /
• 2022

This paper introduces deliberative behavior tree using utility theory. The proposed approach combine the strengths of behavior trees and utility theory to implement complex behavior of AI agents in an easier and more concise way. To achieve this goal, we devised and implemented three types of additional behavior tree nodes, which evaluate utility values of its own node or its subtree while traversing and selecting its child nodes based on the evaluated values. In order to validate our approach, we implemented a sample scenario using conventional behavior tree and our proposed deliberative tree respectively. And then we compared and analyzed the simulation results.

• Journal of Information Processing Systems
• /
• 제7권1호
• /
• pp.173-186
• /
• 2011

Due to the disadvantages of signature-based computer virus detection techniques, behavior-based detection methods have developed rapidly in recent years. However, current popular behavior-based detection methods only take API call sequences as program behavior features and the difference between API calls in the detection is not taken into consideration. This paper divides virus behaviors into separate function modules by introducing DLLs into detection. APIs in different modules have different importance. DLLs and APIs are both considered program calling resources. Based on the calling relationships between DLLs and APIs, program calling resources can be pictured as a tree named program behavior resource tree. Important block structures are selected from the tree as program behavior features. Finally, a virus detection model based on behavior the resource tree is proposed and verified by experiment which provides a helpful reference to virus detection.

• Journal of Multimedia Information System
• /
• 제6권4호
• /
• pp.179-184
• /
• 2019

This paper introduces a study for procedurally generating the behavior of objects in a virtual environment at runtime. This study was initiated to enable the behavioral model of objects in virtual reality applications to evolve in response to user behavior at runtime. Our approach is to describe the behavior of an object as a behavior tree, and to make a node of the behavior tree change to another type if a certain condition is satisfied. We defined four types of node changes: "parameterized", "probabilistic", "alternate", and "variant". We experimented with a virtual environment that includes a variety of simple procedural elements to explore the possibilities of our approach. As a result of the implementation, if an optimization algorithm that can select and apply the optimized procedural elements in response to the user's behavior is complemented, it is confirmed that more intelligent objects and agents can be implemented in virtual reality applications.

• Journal of Multimedia Information System
• /
• 제7권4호
• /
• pp.263-268
• /
• 2020

This paper introduces an event modeling and simulation system using behavior trees. The system aims to overcome the limitations of existing fixed, simple scenario-based training content, and to extend the behavior of objects to enable various experience deployments. To achieve this goal, we made specific tasks of behavior trees can change according to users' reaction and developed an adaptive simulation module that can analyze and execute behavior trees that changes at runtime. In order to validate our approach, we applied the adaptive behavior tree simulation to the scenarios in our virtual reality simulation-based fire training system we have been developing and demonstrated the implementation results.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1998년도 추계학술대회 논문집
• /
• pp.280-287
• /
• 1998

In this paper, Dynamic Fault Tree algorithm(DFT algorithm) is presented. This new algorithm provides a concise representation of dynamic fault tolerance system structure with redundancy, dynamic redundancy management and complex fault ＆ error recovery techniques. And it allows the modeler to define a dynamic fault tree model with the relative advantages of both fault tree and Markov models that captures the system structure and dynamic behavior. This algorithm applies to TMR and Dual-Duplex systems with the dynamic behavior and show that this algorithm captured the dynamic behavior in these systems with fault ＆ error recovery technique, sequence-dependent failures and the use dynamic spare. The DFT algorithm for solving the problems of the systems is more effective than the Markov and Fault tree analysis model.

• Wind and Structures
• /
• 제22권1호
• /
• pp.89-106
• /
• 2016

With an aim to assess the wind damage to urban trees in more realistic conditions, the nonlinear dynamics of structured trees subjected to strong winds with different levels is investigated in the present paper. For the logical treatment of dynamical behavior of trees, material nonlinearities of green wood associated with tree biomechanics and geometric nonlinearity of tree configuration are included. Applying simulated fluctuating wind velocity to the numerical model, the dynamical behavior of the structured tree is explored. A comparative study against the linear dynamics analysis usually involved in the previous researches is carried out. The failure wind velocity of urban trees is then defined, whereby the failure percentages of the tree components are exposed. Numerical investigations reveal that the nonlinear dynamics analysis of urban trees results in a more accurate solution of wind-induced response than the classical linear dynamics analysis, where the nonlinear effect of the tree behavior gives rise to be strengthened as increasing of the levels of wind velocity, i.e., the amplitude of 10-min mean wind velocity. The study of relationship between the failure percentage and the failure wind velocity provides a new perspective towards the vulnerability assessment of urban trees likely to fail due to wind actions, which is potential to link with the practical engineering.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
• /
• pp.1177-1180
• /
• 1996

In this paper, we propose an algorithm that realizes cooperative behavior by construction of autonomous mobile robot system. Each robot is able to sense other robots and obstacles, and it has the rule of behavior to achieve the goal of the system. In this paper, to improve performance of the whole system, we use Genetic Programming based on Natural Selection. Genetic Programming's chromosome is a program of tree structure and it's major operators are crossover and mutation. We verify the effectiveness of the proposed scheme from the several examples.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• 제7권1호
• /
• pp.58-65
• /
• 2007

Behavioral sequences of the medaka (Oryzias latipes) were continuously investigated through an automatic image recognition system in response to medaka treated with the insecticide and medaka not treated with the insecticide, diazinon (0.1 mg/l) during a 1 hour period. The observation of behavior through the movement tracking program showed many patterns of the medaka. After much observation, behavioral patterns were divided into four basic patterns: active-smooth, active-shaking, inactive-smooth, and inactive-shaking. The "smooth" and "shaking" patterns were shown as normal movement behavior. However, the "shaking" pattern was more frequently observed than the "smooth" pattern in medaka specimens that were treated with insecticide. Each pattern was classified using classification methods after the feature choice. It provides a natural way to incorporate prior knowledge from human experts in fish behavior and contains the information in a logical expression tree. The main focus of this study was. to determine whether the decision tree could be useful for interpreting and classifying behavior patterns of the medaka.