• Title/Summary/Keyword: A* algorithm

Search Result 54,193, Processing Time 0.066 seconds

Development of an Enhanced Artificial Life Optimization Algorithm and Optimum Design of Short Journal Bearings (향상된 인공생명 최적화 알고리듬의 개발과 소폭 저널 베어링의 최적설계)

  • Yang, Bo-Suk;Song, Jin-Dae
    • Transactions of the Korean Society for Noise and Vibration Engineering
    • /
    • v.12 no.6
    • /
    • pp.478-487
    • /
    • 2002
  • This paper presents a hybrid method to compute the solutions of an optimization Problem. The present hybrid algorithm is the synthesis of an artificial life algorithm and the random tabu search method. The artificial life algorithm has the most important feature called emergence. The emergence is the result of dynamic interaction among the individuals consisting of the system and is not found in an individual. The conventional artificial life algorithm for optimization is a stochastic searching algorithm using the feature of artificial life. Emergent colonies appear at the optimum locations in an artificial ecology. And the locations are the optimum solutions. We combined the feature of random-tabu search method with the conventional algorithm. The feature of random-tabu search method is to divide any given region into sub-regions. The enhanced artificial life algorithm (EALA) not only converge faster than the conventional artificial life algorithm, but also gives a more accurate solution. In addition, this algorithm can find all global optimum solutions. The enhanced artificial life algorithm is applied to the optimum design of high-speed, short journal bearings and its usefulness is verified through an optimization problem.

Development of an Algorithm for the Prevention and Management of Pressure Ulcers (입원 환자의 욕창예방과 중재를 위한 알고리즘 개발)

  • Kim, Jin-Mi;Park, Jeong-Sook
    • Korean Journal of Adult Nursing
    • /
    • v.22 no.4
    • /
    • pp.353-364
    • /
    • 2010
  • Purpose: The purpose of this study was to develop an algorithm for preventing and managing of pressure ulcer and to verify the its appropriateness. Methods: The first step was development of a pre-algorithm through a literature review and expert opinion. The second step was to establish content validity by submitting the algorithm questionnaires about the content to 12 experts. The third step was the revision of the algorithm. The fourth and last step was to establish the clinical validity of the algorithm with 25 experienced nurses. Results: For the ease of the practitioner the algorithm for prevention and the management of pressure ulcers was confined to one page depicting the main algorithm pathway and seven stepwise guidelines. The guidelines included skin care of pressure ulcer prevention, mechanical loading care, support surface care, reposition care of pressure ulcer, and Stages II, III and IV explanations along with debridement/wound irrigation and infection control. Most of all algorithm courses chosen more than 80% of agreement by expert index of content validity. The usefulness, appropriateness, and convenience of the algorithm were demonstrated through clinical validity with intensive care unit and ward nurses. Conclusion: The algorithm will improve the quality of pressure ulcer nursing care as it provides a model for decision making for clinical nurses as well as providing consistent and integrated nursing care for patients with pressure ulcer throughout an institution.

Development of multiclass traffic assignment algorithm (Focused on multi-vehicle) (다중계층 통행배분 알고리즘 개발 (다차종을 중심으로))

  • 강진구;류시균;이영인
    • Journal of Korean Society of Transportation
    • /
    • v.20 no.6
    • /
    • pp.99-113
    • /
    • 2002
  • The multi-class traffic assignment problem is the most typical one of the multi-solution traffic assignment problems and, recently formulation of the models and the solution algorithm have been received a great deal of attention. The useful solution algorithm, however, has not been proposed while formulation of the multi-class traffic assignment could be performed by adopting the variational inequality problem or the fixed point problem. In this research, we developed a hybrid solution algorithm which combines GA algorithm, diagonal algorithm and clustering algorithm for the multi-class traffic assignment formulated as a variational inequality Problem. GA algorithm and clustering algorithm are introduced for the wide area and small cost. We also performed an experiment with toy network(2 link) and tested the characteristics of the suggested algorithm.

A hybrid algorithm for classifying rock joints based on improved artificial bee colony and fuzzy C-means clustering algorithm

  • Ji, Duofa;Lei, Weidong;Chen, Wenqin
    • Geomechanics and Engineering
    • /
    • v.31 no.4
    • /
    • pp.353-364
    • /
    • 2022
  • This study presents a hybrid algorithm for classifying the rock joints, where the improved artificial bee colony (IABC) and the fuzzy C-means (FCM) clustering algorithms are incorporated to take advantage of the artificial bee colony (ABC) algorithm by tuning the FCM clustering algorithm to obtain the more reasonable and stable result. A coefficient is proposed to reduce the amount of blind random searches and speed up convergence, thus achieving the goals of optimizing and improving the ABC algorithm. The results from the IABC algorithm are used as initial parameters in FCM to avoid falling to the local optimum in the local search, thus obtaining stable classifying results. Two validity indices are adopted to verify the rationality and practicability of the IABC-FCM algorithm in classifying the rock joints, and the optimal amount of joint sets is obtained based on the two validity indices. Two illustrative examples, i.e., the simulated rock joints data and the field-survey rock joints data, are used in the verification to check the feasibility and practicability in rock engineering for the proposed algorithm. The results show that the IABC-FCM algorithm could be applicable in classifying the rock joint sets.

A Study on the Face Recognition Using PCA Algorithm

  • Lee, John-Tark;Kueh, Lee-Hui
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.17 no.2
    • /
    • pp.252-258
    • /
    • 2007
  • In this paper, a face recognition algorithm system using Principal Component Analysis (PCA) is proposed. The algorithm recognized a person by comparing characteristics (features) of the face to those of known individuals of Intelligent Control Laboratory (ICONL) face database. Simulations are carried out to investigate the algorithm recognition performance, which classified the face as a face or non-face and then classified it as known or unknown one. Particularly, a Principal Components of Linear Discriminant Analysis (PCA + LDA) face recognition algorithm is also proposed in order to confirm the recognition performances and the adaptability of a proposed PCA for a certain specific system.

A Study on Applying Genetic Algorithm for Optimum Virtual Path Network Design in ATM Network (ATM 망에서 최적 가상 경로망 설계를 위한 유전자 알고리즘 응용에 관한 연구)

  • 강주락;권기호
    • Proceedings of the IEEK Conference
    • /
    • 2000.06c
    • /
    • pp.31-34
    • /
    • 2000
  • Genetic Algorithm is well known as the efficient algorithm which can solve a difficult optimization problem. Recently, there has been increasing interest in applying genetic algorithm to problem related to network design. In this paper, we propose a two-step genetic algorithm for designing a optimum virtual path network(VPN) for a given physical network and traffic demand. The first step is a routing step in which a route is found between every node pair in the network. In the second step, paths are assigned as VPs so as to minimize the total number of VPs configured, the number of VPs carried by a link, and the VP hopcount. We study the performance of the propose algorithm through simulation. The result shows that the VPN generated by the proposed algorithm is good in minimizing the number of VPs configured, the load on a link, and the VP hopcount.

  • PDF

A New Method for Efficient in-Place Merging

  • Kim, Pok-Son;Arne Kutzner
    • Proceedings of the Korean Institute of Intelligent Systems Conference
    • /
    • 2003.09a
    • /
    • pp.392-394
    • /
    • 2003
  • There is a well-known simple, stable standard merge algorithm, which uses only linear time but for the price of double space. This extra space consumption has been often remarked as lack of the standard merge sort algorithm that covers a merge process as central operation. In-place merging is a way to overcome this lack and so is a topic with a long tradition of inspection in the area of theoretical computer science. We present an in-place merging algorithm that rear-ranges the elements to be merged by rotation, a special form of block interchanging. Our algorithm is novel, due to its technique of determination of the rotation-areas. Further it has a short and transparent definition. We will give a presentation of our algorithm and prove that it needs in the worst case not more than twice as much comparisons as the standard merge algorithm. Experimental work has shown that our algorithm is efficient and so might be of high practical interest.

  • PDF

VTA* Algorithm: A* Path-Finding Algorithm using Variable Turn Heuristic (VTA* 알고리즘: 가변적인 턴 휴리스틱을 적용한 A* 경로탐색 알고리즘)

  • Kim, Ji-Soo;Cho, Dae-Soo
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.14 no.3
    • /
    • pp.663-668
    • /
    • 2010
  • In driving a car, turns such as left turns, right turns, or u-turns, make the speed of the car decrease considerably. A more straight path, therefore, is probably faster to arrive at the destination than zig-zag path with same distance. In this paper, we have newly proposed the turn heuristic to make more straight path. The path navigation algorithm with turn heuristic(called as TA* algorithm) could enhance the straightness of a path by putting the turned-edges to the turn cost. It requires higher cost to use TA* algorithm than traditional A* algorithm because the straight-edge first searching have increased the search space. We have improved the TA* algorithm into the variable TA* algorithm(called as VTA* algorithm) which adopt the turn-heuristic during the a portion of the whole path.

A Speed-Based Dijkstra Algorithm for the Line Tracer Control of a Robot (로봇 경로 제어를 위한 속도기반 Dijkstra 알고리즘)

  • Cheon, Seong-Kwon;Kim, Geun-Deok;Kim, Chong-Gun
    • Journal of Information Technology Services
    • /
    • v.10 no.4
    • /
    • pp.259-268
    • /
    • 2011
  • A robot education system by emulation based on Web can be efficiently used for understanding concept of robot assembly practice and control mechanism of robot by control programming. It is important to predict the path of the line tracer robot which has to be decided by the robot. Shortest Path Algorithm is a well known algorithm which searches the most efficient path between the start node and the end node. There are two related typical algorithms. Dijkstra Algorithm searches the shortest path tree from a node to the rest of the other nodes. $A^*$ Algorithm searches the shortest paths among all nodes. The delay time caused by turning the direction of navigation for the line tracer robot at the crossroads can give big differences to the travel time of the robot. So we need an efficient path determine algorithm which can solve this problem. Thus, It is necessary to analyze the overhead of changing direction of robot at multi-linked node to determine the next direction for efficient routings. In this paper, we reflect the real delay time of directional changing from the real robot. A speed based Dijkstra algorithm is proposed and compared with the previous ones to analyze the performance.

The Supply Water Algorithm for a Condensing Gas Boiler Control (콘덴싱가스보일러 제어를 위한 공급수알고리즘)

  • Han, Do-Young;Yoo, Byeong-Kang
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.23 no.6
    • /
    • pp.441-448
    • /
    • 2011
  • The energy consumption of a condensing gas boiler may be greatly reduced by the effective operation of the unit. In this study, the supply water algorithm for a condensing gas boiler control was developed by using the fuzzy logic. This includes the supply water set temperature algorithm, and the control algorithms of a gas valve, a blower and a pump. For the set temperature algorithm, the outside air temperature and the return water temperature were used as input variables. The supply water temperature difference and its slope were used as input variables of the gas valve and blower control algorithm. And the supply water temperature and the return water temperature were used as input variables of the pump control algorithm. In order to analyse performances of these algorithms, the dynamic model of a condensing gas boiler was used. The initial start-up test, the supply water set temperature change test, the outside air temperature change test, and the return water temperature change test were performed. Simulation results showed that algorithms developed in this study may be practically applied for the effective control of a condensing gas boiler.