• Title/Summary/Keyword: GREEDY

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Polynomial-time Greedy Algorithm for Anti-Air Missiles Assignment Problem (지대공 미사일 배정 문제의 다항시간 탐욕 알고리즘)

  • Lee, Sang-Un
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.19 no.3
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    • pp.185-191
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    • 2019
  • During the modern battlefields of multi-batches flight formation attack situation, it is an essential task for a commander to make a proper fire distribution of air defense missile launch platforms for threat targets with effectively and quickly. Pan et al. try to solve this problem using genetic algorithm, but they are fails. This paper gets the initial feasible solution using high threat target first destroying strategy only use 75% available fire of each missile launch platform. Then, the assigned missile is moving to another target in the case of decreasing total threat. As a result of experiment, while the proposed algorithm is polynomial-time complexity greedy algorithm but this can be improve the solution than genetic algorithm.

Correlation Distance Based Greedy Perimeter Stateless Routing Algorithm for Wireless Sensor Networks

  • Mayasala, Parthasaradhi;Krishna, S Murali
    • International Journal of Computer Science & Network Security
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    • v.22 no.1
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    • pp.139-148
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    • 2022
  • Research into wireless sensor networks (WSNs) is a trendy issue with a wide range of applications. With hundreds to thousands of nodes, most wireless sensor networks interact with each other through radio waves. Limited computational power, storage, battery, and transmission bandwidth are some of the obstacles in designing WSNs. Clustering and routing procedures have been proposed to address these concerns. The wireless sensor network's most complex and vital duty is routing. With the Greedy Perimeter Stateless Routing method (GPSR), an efficient and responsive routing protocol is built. In packet forwarding, the nodes' locations are taken into account while making choices. In order to send a message, the GPSR always takes the shortest route between the source and destination nodes. Weighted directed graphs may be constructed utilising four distinct distance metrics, such as Euclidean, city block, cosine, and correlation distances, in this study. NS-2 has been used for a thorough simulation. Additionally, the GPSR's performance with various distance metrics is evaluated and verified. When compared to alternative distance measures, the proposed GPSR with correlation distance performs better in terms of packet delivery ratio, throughput, routing overhead and average stability time of the cluster head.

A Novel Duty Cycle Based Cross Layer Model for Energy Efficient Routing in IWSN Based IoT Application

  • Singh, Ghanshyam;Joshi, Pallavi;Raghuvanshi, Ajay Singh
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.6
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    • pp.1849-1876
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    • 2022
  • Wireless Sensor Network (WSN) is considered as an integral part of the Internet of Things (IoT) for collecting real-time data from the site having many applications in industry 4.0 and smart cities. The task of nodes is to sense the environment and send the relevant information over the internet. Though this task seems very straightforward but it is vulnerable to certain issues like energy consumption, delay, throughput, etc. To efficiently address these issues, this work develops a cross-layer model for the optimization between MAC and the Network layer of the OSI model for WSN. A high value of duty cycle for nodes is selected to control the delay and further enhances data transmission reliability. A node measurement prediction system based on the Kalman filter has been introduced, which uses the constraint based on covariance value to decide the scheduling scheme of the nodes. The concept of duty cycle for node scheduling is employed with a greedy data forwarding scheme. The proposed Duty Cycle-based Greedy Routing (DCGR) scheme aims to minimize the hop count, thereby mitigating the energy consumption rate. The proposed algorithm is tested using a real-world wastewater treatment dataset. The proposed method marks an 87.5% increase in the energy efficiency and reduction in the network latency by 61% when validated with other similar pre-existing schemes.

Hierarchical Resource Management Framework and Multi-hop Task Scheduling Decision for Resource-Constrained VEC Networks

  • Hu, Xi;Zhao, Yicheng;Huang, Yang;Zhu, Chen;Yao, Jun;Fang, Nana
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.11
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    • pp.3638-3657
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    • 2022
  • In urban vehicular edge computing (VEC) environments, one edge server always serves many task requests in its coverage which results in the resource-constrained problem. To resolve the problem and improve system utilization, we first design a general hierarchical resource management framework based on typical VEC network structures. Following the framework, a specific interacting protocol is also designed for our decision algorithm. Secondly, a greedy bidding-based multi-hop task scheduling decision algorithm is proposed to realize effective task scheduling in resource-constrained VEC environments. In this algorithm, the goal of maximizing system utility is modeled as an optimization problem with the constraints of task deadlines and available computing resources. Then, an auction mechanism named greedy bidding is used to match task requests to edge servers in the case of multiple hops to maximize the system utility. Simulation results show that our proposal can maximize the number of tasks served in resource constrained VEC networks and improve the system utility.

An Enhanced Greedy Message Forwarding Protocol for High Mobile Inter-vehicular Communications (고속으로 이동하는 차량간 통신에서 향상된 탐욕 메시지 포워딩 프로토콜)

  • Jang, Hyun-Hee;Yu, Suk-Dae;Park, Jae-Bok;Cho, Gi-Hwan
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.3
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    • pp.48-58
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    • 2009
  • Geo-graphical routing protocols as GPSR are known to be very suitable and useful for vehicular ad-hoc networks. However, a corresponding node can include some stale neighbor nodes being out of a transmission range, and the stale nodes are pone to get a high priority to be a next relay node in the greedy mode. In addition, some useful redundant information can be eliminated during planarization in the recovery mode. This paper deals with a new recovery mode, the Greedy Border Superiority Routing(GBSR), along with an Adaptive Neighbor list Management(ANM) scheme. Each node can easily treat stale nodes on its neighbor list by means of comparing previous and current Position of a neighbor. When a node meets the local maximum, it makes use of a border superior graph to recover from it. This approach improve the packet delivery ratio while it decreases the time to recover from the local maximum. We evaluate the performance of the proposed methods using a network simulator. The results shown that the proposed protocol reveals much better performance than GPSR protocol. Please Put the of paper here.

Segmentation Algorithm for Wafer ID using Active Multiple Templates Model

  • Ahn, In-Mo;Kang, Dong-Joong;Chung, Yoon-Tack
    • 제어로봇시스템학회:학술대회논문집
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    • 2003.10a
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    • pp.839-844
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    • 2003
  • This paper presents a method to segment wafer ID marks on poor quality images under uncontrolled lighting conditions of the semiconductor process. The active multiple templates matching method is suggested to search ID areas on wafers and segment them into meaningful regions and it would have been impossible to recognize characters using general OCR algorithms. This active template model is designed by applying a snake model that is used for active contour tracking. Active multiple template model searches character areas and segments them into single characters optimally, tracking each character that can vary in a flexible manner according to string configurations. Applying active multiple templates, the optimization of the snake energy is done using Greedy algorithm, to maximize its efficiency by automatically controlling each template gap. These vary according to the configuration of character string. Experimental results using wafer images from real FA environment are presented.

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Speaker Identification Using an Ensemble of Feature Enhancement Methods (특징 강화 방법의 앙상블을 이용한 화자 식별)

  • Yang, IL-Ho;Kim, Min-Seok;So, Byung-Min;Kim, Myung-Jae;Yu, Ha-Jin
    • Phonetics and Speech Sciences
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    • v.3 no.2
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    • pp.71-78
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    • 2011
  • In this paper, we propose an approach which constructs classifier ensembles of various channel compensation and feature enhancement methods. CMN and CMVN are used as channel compensation methods. PCA, kernel PCA, greedy kernel PCA, and kernel multimodal discriminant analysis are used as feature enhancement methods. The proposed ensemble system is constructed with the combination of 15 classifiers which include three channel compensation methods (including 'without compensation') and five feature enhancement methods (including 'without enhancement'). Experimental results show that the proposed ensemble system gives highest average speaker identification rate in various environments (channels, noises, and sessions).

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Parallel Information Retrieval with Query Expansion (질의 확장을 이용한 병렬 정보 검색)

  • 정유진
    • Proceedings of the Korean Information Science Society Conference
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    • 2002.04b
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    • pp.103-105
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    • 2002
  • 이 논문에서는, PC 클러스터 환경에서 질의 확장을 사용하는 정보 검색 시스템 (IR)을 설계하고 구현한 내용을 기술한다. 이 정도 검색 시스템은 문서 집합을 저장하고, 문서 집합은 역색인 파인 (IIF)로 색인되고, 랭킹 방법으로 벡터 모델을 사실하며, 질의 확장 방법으로 코사인 유사도를 사용한다. 질의 확장이란 사용자가 준 원래의 질의에 연관된 단어를 추가하여 검색 효율을 향상시키는 것이다. 여기서 제안하는 병렬 정보 검색 시스템에서는 역색인 과일은 여러 개로 분활되는데 lexical 분할 방법과 greedy 분할 방법을 사용한다. 사용자의 질의가 들어오면 질의확장을 하여 여러 개의 단어로 이루어진 확장된 질의가 만들어 지는데 이 확장된 질의를 구성하는 단어들은 각 단어와 연관된 IIF를 가지고 있는 노드에 보내어져서 병렬로 처리된다. 실험을 통하여 병렬 IR 시스템의 성능이 질의 확장과 IIF의 두 가지 분한 방법에 의해 어떻게 영향을 받는지 보인다. 실험에는 표준 한국어 테스트 말뭉치인 EKSET과 KTSET을 사용하였다. 실험에 따르면 greedy 분활 방법이 lexical 분할 방법에 비해 20%정도의 성능 향상을 보였다.

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A Markov Decision Process (MDP) based Load Balancing Algorithm for Multi-cell Networks with Multi-carriers

  • Yang, Janghoon
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.10
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    • pp.3394-3408
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    • 2014
  • Conventional mobile state (MS) and base station (BS) association based on average signal strength often results in imbalance of cell load which may require more powerful processor at BSs and degrades the perceived transmission rate of MSs. To deal with this problem, a Markov decision process (MDP) for load balancing in a multi-cell system with multi-carriers is formulated. To solve the problem, exploiting Sarsa algorithm of on-line learning type [12], ${\alpha}$-controllable load balancing algorithm is proposed. It is designed to control tradeoff between the cell load deviation of BSs and the perceived transmission rates of MSs. We also propose an ${\varepsilon}$-differential soft greedy policy for on-line learning which is proven to be asymptotically convergent to the optimal greedy policy under some condition. Simulation results verify that the ${\alpha}$-controllable load balancing algorithm controls the behavior of the algorithm depending on the choice of ${\alpha}$. It is shown to be very efficient in balancing cell loads of BSs with low ${\alpha}$.

An Efficient Robot Path Generation Using Delaunay Mesh (딜레노이 메시를 이용한 효율적인 로봇 경로 생성방법)

  • Noh, Sung-Woo;Ko, Nak-Yong;Kim, Kwang-Jin
    • The Journal of Korea Robotics Society
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    • v.5 no.1
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    • pp.41-47
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    • 2010
  • This paper proposes a path planning method of a mobile robot in two-dimensional work space. The path planning method is based on a cell decomposition approach. To create a path which consists of a number of line segments, the Delaunay Triangulation algorithm is used. Using the cells produced by the Delaunay Triangulation algorithm, a mesh generation algorithm connects the starting position to the goal position. Dijkstra algorithm is used to find the shortest distance path. Greedy algorithm optimizes the path by deleting the path segments which detours without collision with obstacles.