• Title/Summary/Keyword: Path-finding

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The Research on Extraction of Topology Model Using Straight Medial Axis Transformation Algorithm (SMAT 알고리즘을 이용한 위상학적 모델 추출 방법)

  • Park, So-Young;Lee, Ji-Yeong
    • Spatial Information Research
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    • v.20 no.2
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    • pp.117-127
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    • 2012
  • The purpose of this study is to develop the auto-building algorithm of the Geometric Network Model(GNM), a topology model including geometric information because of the need to reflect the features' geometric characteristic into the topology model, which is for development of indoor 3D virtual model enabling queries. As the critical algorithm, the Straight Medial Axis Transformation(SMAT) algorithm is proposed in order to automatically extract the medial axis of features. The SMAT algorithm is generalized from the existing S-MAT algorithm and a range of target features where applicable is extended from simple polygons to weakly simple polygons which mean the polygons containing the inner ring inside. The GNM built automatically is finally printed out as the .csv file for easy access and w ide application in other systems. This auto-building algorithm of the GNM is available for plenty of cases such as finding a shortest path, guiding a route in emergency situation, and semantic analysis.

Implementation of NPC Artificial Intelligence Using Agonistic Behavior of Animals (동물의 세력 투쟁 행동을 이용한 게임 인공 지능 구현)

  • Lee, MyounJae
    • Journal of Digital Convergence
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    • v.12 no.1
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    • pp.555-561
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    • 2014
  • Artificial intelligence in the game is mainly used to determine patterns of behavior of NPC (Non Player Character) and the enemy, path finding. These artificial intelligence is implemented by FSM (Finite State Machine) or Flocking method. The number of NPC behavior in FSM method is limited by the number of FSM states. If the number of states is too small, then NPC player can know the behavior patterns easily. On the other hand, too many implementation cases make it complicated. The NPC behaviors in Flocking method are determined by the leader's decision. Therefore, players can know easily direction of movement patterns or attack pattern of NPCs. To overcome these problem, this paper proposes agonistic behaviors(attacks, threats, showing courtesy, avoidance, submission)in animals to apply for the NPC, and implements agonistic behaviors using Unity3D engine. This paper can help developing a real sense of the NPC artificial intelligence.

Detecting Inner Attackers and Colluded nodes in Wireless Sensor Networks Using Hop-depth algorithm (Hop-depth 알고리즘을 이용한 무선 센서 네트워크상에서의 내부공격자 및 공모노드 검출)

  • Rhee, Kang-Hyeon
    • Journal of the Institute of Electronics Engineers of Korea CI
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    • v.44 no.1
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    • pp.113-121
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    • 2007
  • Commonly, in the Sensor Network that composed with multiple nodes uses Ad-hoc protocol to communicate each other. Each sensed data packets are collected by base node and processed by Host PC. But the Ad-hoc protocol is too vulnerable to Sinkhole attack, where the intruder attracts surrounding nodes with unfaithful routing information, and then performs selective forwarding or changes the data passing through it. The Sinkhole attack increases overhead over the network and boosts energy consumption speed to decrease network's life time. Since the other attacks can be easily adopted through sinkhole attack, the countermeasure must be considered carefully. In this paper, we proposed the Hop-depth algorithm that detects intruder in Sinkhole attack and colluded nodes. First, the proposed algorithm makes list of suspected nodes and identifies the real intruder in the suspected node list through the Hop-depth count value. And recalculates colluder's path information to find the real intruder. We evaluated the performance of the proposed algorithm using NS2. We compared and analyzed the success ratio of finding real intruder, false positive ratio, false negative ratio, and energy consumption.

Testing Measurement Invariance of the School Vitality Scale Across The Level of School (학교활력 진단도구의 학교급 간 측정동일성 검정)

  • Lee, Jae-Duck
    • The Journal of the Korea Contents Association
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    • v.20 no.3
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    • pp.41-48
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    • 2020
  • The purpose of this study is testing measurement invariance of the school vitality scale across the level of school. For this study, 3,156 elementary school teachers and 4,411 secondary school teachers were surveyed. As a result, school vitality scale was found to have the same factor structure in the structure regression model. Second, the factor load of the measurement model was found to be the same. Third, the structural path coefficients were the same. Fourth, structural covariance was found to be the same. Fifth, the structural residuals were the same. Based on these findings, it can be concluded that we can use school vitality scale both elementary school and secondary school. This study will contribute to diagnosing school vitality levels and finding ways to improve school management.

The Impact of Competition on Universal Service in Korea (경쟁도입이 한국의 보편적 서비스에 미친 영향)

  • Kim, Sung Wook
    • Informatization Policy
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    • v.17 no.4
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    • pp.80-99
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    • 2010
  • A substantial body of theoretical and case study literature exists about the relationship between competition and universal service in developing countries. On the one hand, many scholars have argued that state-owned monopolies in developing countries are not able to mobilize the capital needed for network expansion: the resulting unmet demand for services becomes a motivator for liberalization. On the other hand, the introduction of competition jeopardizes the internal and external subsidies through which the state-owned monopoly kept subscription rates low: the heightened concern about loss of subscribership incentivizes the creation of explicit universal service statutes and funding mechanisms concurrently with or soon after competition is introduced. This paper shows that universal service in Korea had a unique evolutionary path, which did not conform to either of these expectations. From this finding, it reaches the conclusion that the outcomes predicted by theory and observed in the case study literature are not intrinsic to the monopoly condition per se, but derive from the strategic choices made by telecommunications managers, regulators and lawmakers in developing countries.

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A Fuzzy Evaluation Method of Traveler's Path Choice in Transportation Network (퍼지평가방법을 이용한 교통노선 결정)

  • 이상훈;김덕영;김성환
    • Journal of Korean Society of Transportation
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    • v.20 no.1
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    • pp.65-76
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    • 2002
  • This study is realized using fuzzy evaluation and AHP(the analytic hierarchy process) for the optimum search of traffic route and estimated by the quantitative analysis in the vague subjective judgement. It is different from classical route search and noticed thinking method of human. Appraisal element, weight, appraisal value of route is extracted from basic of the opinion gathering fur the driving expert and example of route model was used for the finding of practice utility. Model assessment was performed attribute membership function making of estimate element, estimate value setting, weight define by the AHP, non additive presentation of weight according to $\lambda$-fuzzy measure, Choquet fuzzy integral.

Effect of Male-Sterile Cytoplasm on the Genetic Performance of Agronomic Traits in $F_1$ Hybrid Rices

  • Lin, Wen-Xiong;Kim, Kil-Ung;Shin, Dong-Hyun;Lee, In-Jung;He, Shui-Lin;Moon, Huhn-Pal
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.43 no.2
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    • pp.59-63
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    • 1998
  • Three different male-sterile cytoplasmic lines and their common maintainer 'Zhenshan 97B' and two elite restorer lines were used to study cytoplasmic effects on agronomic trait manifestation per se under different nitrogen supply levels. The result showed that cytoplasmic effects could be modified by nitrogen environments. The cytoplasmic effect on grain yield under 150 kg N/ha varied depending on crosses, while it was significantly negative in most crosses under both 60 and 330 kg N/ha. The correlation and path-coefficient analyses suggested that it was expected to improve cytoplasmic effects through reducing maximum tillers and increasing the percentage of productive tillers, leading to increased productive tillers and higher yield in hybrid rice by the aid of cultural practice and genetic transformation. This study also revealed that the same cytoplasm in different combinations had differential effect under the same nitrogen environment, indicating that cytoplasmic effect was produced by interaction of nuclear genes with cytoplasm rather than cytoplasm per se. These results indicated the usefulness of evaluating diverse cytoplasmic sources in various nuclear genotypes bred for hybrid rice breeding program. The finding also suggested that negative cytoplasmic effect could be effectively overcome by elite restorer lines through the interaction of nuclear genes with female cytoplasm.

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Real-time Graph Search for Space Exploration (공간 탐사를 위한 실시간 그래프 탐색)

  • Choi, Eun-Mi;Kim, In-Cheol
    • Journal of Intelligence and Information Systems
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    • v.11 no.1
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    • pp.153-167
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    • 2005
  • In this paper, we consider the problem of exploring unknown environments with a mobile robot or an autonomous character agent. Traditionally, research efforts to address the space exploration problem havefocused on the graph-based space representations and the graph search algorithms. Recently EXPLORE, one of the most efficient search algorithms, has been discovered. It traverses at most min$min(mn, d^2+m)$ edges where d is the deficiency of a edges and n is the number of edges and n is the number of vertices. In this paper, we propose DFS-RTA* and DFS-PHA*, two real-time graph search algorithms for directing an autonomous agent to explore in an unknown space. These algorithms are all built upon the simple depth-first search (DFS) like EXPLORE. However, they adopt different real-time shortest path-finding methods for fast backtracking to the latest node, RTA* and PHA*, respectively. Through some experiments using Unreal Tournament, a 3D online game environment, and KGBot, an intelligent character agent, we analyze completeness and efficiency of two algorithms.

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Geometric LiveWire and Geometric LiveLane for 3D Meshes (삼차원 메쉬에 대한 기하학 라이브와이어와 기하학 라이브레인)

  • Yoo Kwan-Hee
    • The KIPS Transactions:PartA
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    • v.12A no.1 s.91
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    • pp.13-22
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    • 2005
  • Similarly to the edges defined in a 2D image, we can define the geometric features representing the boundary of the distinctive parts appearing on 3D meshes. The geometric features have been used as basic primitives in several applications such as mesh simplification, mesh deformation, and mesh editing. In this paper, we propose geometric livewire and geometric livelane for extracting geometric features in a 3D mesh, which are the extentions of livewire and livelane methods in images. In these methods, approximate curvatures are adopted to represent the geometric features in a 3D mesh and the 3D mesh itself is represented as a weighted directed graph in which cost functions are defined for the weights of edges. Using a well-known shortest path finding algorithm in the weighted directed graph, we extracted geometric features in the 3D mesh among points selected by a user. In this paper, we also visualize the results obtained from applying the techniques to extracting geometric features in the general meshes modeled after human faces, cows, shoes, and single teeth.

A Study of SSA Routing Protocol using Utilization Metric in Ad Hoc Networks (Ad Hoc 환경에서의 Utilization Metric을 이용한 SSA 라우팅 프로토콜에 관한 연구)

  • Ji Jong-Bok;Park Joo-Ha;Lee Kaug-Seok;Song Joo-Seok
    • The KIPS Transactions:PartC
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    • v.12C no.4 s.100
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    • pp.543-550
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    • 2005
  • Many routing algorithms, proposed for ad-hoc wireless networks, we based on source routing scheme and shortest path route has short lifetime especially in highly dense ad-hoc wireless networks. So some routing protocols such as SSA and ABR are considering the link stability and try finding more stable route. In this paper we propose a new routing algorithm considering utilization metric based on SSA routing algerian in Ad-Hoc networks. To reduce the bottleneck by specific metric of SSA, proposed scheme makes load balancing in networks by distributing the connections to several routes. For the evaluation of the performance we compare our scheme with existent routing protocol AODV and SSA. And the results, obtained using the ns-2 network simulation platform, show good performance that reduced the number of reconstructions remarkably by distributing the whole traffic to several routes when there are several stable routes.