• Title/Summary/Keyword: global networks

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Collocation Networks and Covid-19 in Letters to the Editor: A Malaysian Case Study

  • Joharry, Siti Aeisha;Turiman, Syamimi
    • Asia Pacific Journal of Corpus Research
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    • v.1 no.1
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    • pp.1-30
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    • 2020
  • The present study examines language used to talk about the global coronavirus pandemic during a three-month period of movement control order in Malaysia. More specifically, a corpus of online letters to the editor of a local popular national newspaper was collected during the time in which the official quarantine instruction was initiated, resulting in a total of 303 online letters written by Malaysians that were analyzed through use of corpus linguistics techniques. For this purpose, the latest version of #LancsBox 5.0 (Brezina et al., 2020) is used to analyze patterns of language surrounding the portrayal of Covid-19 and further visualizing them by use of collocation networks. Findings present 25 statistically significant collocates that share an interesting relationship in revealing what the letters are about and thus, reflecting how Malaysians perceive and receive news about the pandemic during this time. Recurring topics and expressions include describing the virus in terms of metaphorical use of language (Covid-19 does not discriminate), preparing for an economic fallout (Prihatin Economic Stimulus Package), and preference to associate Covid-19 as a pandemic (impacts of the Covid19 pandemic) rather than an outbreak (first/second/third wave of the outbreak). Implications of the study resonates with findings from Azizan et al. (2020) where constructions of positive discourse among Malaysian writers may reflect the culture and society that make up the nation.

Design of CNN Chip with Annealing Capability (어닐링 기능을 갖는 셀룰러 신경망 칩 설계)

  • 유성환;전흥우
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.11
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    • pp.46-54
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    • 1999
  • The output values of cellular neural networks would have errors because they can be stabilized at local minimums depending on the initial states of each cell. So, in this paper, we design the $6\times6$cellular neural networks with annealing capability which guarantees that the outputs reaches the global minimum to have correct output values independent of the initial states of each cell. This chip is designed using a $0.8\mu\textrm{m}$ CMOS technology The designed chip contains about 15,000 transistors and the chip size is about $2.89\times2.89\textrm{mm}^2$. The simulation results of edge extraction and hole filling using the designed circuit show that the outputs values would have errors in un-annealed case, but not in annealed case. In the simulation, the annealing time of $3\musec$ is employed.

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Reactor Vessel Water Level Estimation During Severe Accidents Using Cascaded Fuzzy Neural Networks

  • Kim, Dong Yeong;Yoo, Kwae Hwan;Choi, Geon Pil;Back, Ju Hyun;Na, Man Gyun
    • Nuclear Engineering and Technology
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    • v.48 no.3
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    • pp.702-710
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    • 2016
  • Global concern and interest in the safety of nuclear power plants have increased considerably since the Fukushima accident. In the event of a severe accident, the reactor vessel water level cannot be measured. The reactor vessel water level has a direct impact on confirming the safety of reactor core cooling. However, in the event of a severe accident, it may be possible to estimate the reactor vessel water level by employing other information. The cascaded fuzzy neural network (CFNN) model can be used to estimate the reactor vessel water level through the process of repeatedly adding fuzzy neural networks. The developed CFNN model was found to be sufficiently accurate for estimating the reactor vessel water level when the sensor performance had deteriorated. Therefore, the developed CFNN model can help provide effective information to operators in the event of a severe accident.

A Localization Scheme Using Mobile Robot in Wireless Sensor Networks (무선 센서 네트워크에서 이동성 로봇을 이용한 센서 위치 인식 기법에 관한 연구)

  • Kim, Woo-Hyun
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.2
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    • pp.105-113
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    • 2007
  • Accurate and low-cost sensor localization is a critical requirement for the deployment of wireless sensor networks in a wide variety of application. Sensor position is used for its data to be meaningful and for energy efficient data routing algorithm especially geographic routing. The previous works for sensor localization utilize global positioning system(GPS) or estimate unknown-location nodes position with help of some small reference nodes which know their position previously. However, the traditional localization techniques are not well suited in the senor network for the cost of sensors is too high. In this paper, we propose the sensor localization method with a mobile robot, which knows its position, moves through the sensing field along pre-scheduled path and gives position information to the unknown-location nodes through wireless channel to estimate their position. We suggest using the sensor position estimation method and an efficient mobility path model. To validate our method, we carried out a computer simulation, and observed that our technique achieved sensor localization more accurately and efficiently than the conventional one.

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An Energy Efficient Distributed Approach-Based Agent Migration Scheme for Data Aggregation in Wireless Sensor Networks

  • Gupta, Govind P.;Misra, Manoj;Garg, Kumkum
    • Journal of Information Processing Systems
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    • v.11 no.1
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    • pp.148-164
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    • 2015
  • The use of mobile agents for collaborative processing in wireless sensor network has gained considerable attention. This is when mobile agents are used for data aggregation to exploit redundant and correlated data. The efficiency of agent-based data aggregation depends on the agent migration scheme. However, in general, most of the proposed schemes are centralized approach-based schemes where the sink node determines the migration paths for the agents before dispatching them in the sensor network. The main limitations with such schemes are that they need global network topology information for deriving the migration paths of the agents, which incurs additional communication overhead, since each node has a very limited communication range. In addition, a centralized approach does not provide fault tolerant and adaptive migration paths. In order to solve such problems, we have proposed a distributed approach-based scheme for determining the migration path of the agents where at each hop, the local information is used to decide the migration of the agents. In addition, we also propose a local repair mechanism for dealing with the faulty nodes. The simulation results show that the proposed scheme performs better than existing schemes in the presence of faulty nodes within the networks, and manages to report the aggregated data to the sink faster.

A Study on Kohenen Network based on Path Determination for Efficient Moving Trajectory on Mobile Robot

  • Jin, Tae-Seok;Tack, HanHo
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.10 no.2
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    • pp.101-106
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    • 2010
  • We propose an approach to estimate the real-time moving trajectory of an object in this paper. The object's position is obtained from the image data of a CCD camera, while a state estimator predicts the linear and angular velocities of the moving object. To overcome the uncertainties and noises residing in the input data, a Extended Kalman Filter(EKF) and neural networks are utilized cooperatively. Since the EKF needs to approximate a nonlinear system into a linear model in order to estimate the states, there still exist errors as well as uncertainties. To resolve this problem, in this approach the Kohonen networks, which have a high adaptability to the memory of the inputoutput relationship, are utilized for the nonlinear region. In addition to this, the Kohonen network, as a sort of neural network, can effectively adapt to the dynamic variations and become robust against noises. This approach is derived from the observation that the Kohonen network is a type of self-organized map and is spatially oriented, which makes it suitable for determining the trajectories of moving objects. The superiority of the proposed algorithm compared with the EKF is demonstrated through real experiments.

The Meaning of Geographical Education of Commodity through Relational Thinking (관계적 사고를 통한 상품의 지리 교육적 의미)

  • Kim, Byung-Yeon
    • Journal of the Korean Geographical Society
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    • v.46 no.4
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    • pp.554-566
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    • 2011
  • Consumer capitalism is transforming real geographical knowledge into imaginary one through commodity fetishism. As a result, students' ability to think themselves and commodity relationally become weak. Thus, the students cannot recognize the positional meanings of themselves in the global networks of food and ethically perceive environmental issues that generate due to the interrelation between the students and the commodity networks. In these problematic consciousness and situations, this research examine relation of commodity consumption and ethics through hamburger connection and insists that geographical education helps the students acquire insight into the relationship between food and themselves through relational thinking.

A novel clustering method for examining and analyzing the intellectual structure of a scholarly field (지적 구조 분석을 위한 새로운 클러스터링 기법에 관한 연구)

  • Lee, Jae-Yun
    • Journal of the Korean Society for information Management
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    • v.23 no.4 s.62
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    • pp.215-231
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    • 2006
  • Recently there are many bibliometric studies attempting to utilize Pathfinder networks(PFNets) for examining and analyzing the intellectual structure of a scholarly field. Pathfinder network scaling has many advantages over traditional multidimensional scaling, including its ability to represent local details as well as global intellectual structure. However there are some limitations in PFNets including very high time complexity. And Pathfinder network scaling cannot be combined with cluster analysis, which has been combined well with traditional multidimensional scaling method. In this paper, a new method named as Parallel Nearest Neighbor Clustering (PNNC) are proposed for complementing those weak points of PFNets. Comparing the clustering performance with traditional hierarchical agglomerative clustering methods shows that PNNC is not only a complement to PFNets but also a fast and powerful clustering method for organizing informations.

Development of UAV Teleoperation Virtual Environment Based-on GSM Networks and Real Weather Effects

  • AbdElHamid, Amr;Zong, Peng
    • International Journal of Aeronautical and Space Sciences
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    • v.16 no.3
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    • pp.463-474
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    • 2015
  • Future Ground Control Stations (GCSs) for Unmanned Aerial Vehicles (UAVs) teleoperation targets better situational awareness by providing extra motion cues to stimulate the vestibular system. This paper proposes a new virtual environment for long range Unmanned Aerial Vehicle (UAV) control via Non-Line-of-Sight (NLoS) communications, which is based on motion platforms. It generates motion cues for the teleoperator for extra sensory stimulation to enhance the guidance performance. The proposed environment employs the distributed component simulation over GSM network as a simulation platform. GSM communications are utilized as a multi-hop communication network, which is similar to global satellite communications. It considers a UAV mathematical model and wind turbulence effects to simulate a realistic UAV dynamics. Moreover, the proposed virtual environment simulates a Multiple Axis Rotating Device (MARD) as Human Machine Interface (HMI) device to provide a complete delay analysis. The demonstrated measurements cover Graphical User Interface (GUI) capabilities, NLoS GSM communications delay, MARD performance, and different software workload. The proposed virtual environment succeeded to provide visual and vestibular feedbacks for teleoperators via GSM networks. The overall system performance is acceptable relative to other Line-of-Sight (LoS) systems, which promises a good potential for future long range, medium altitude UAV teleoperation researches.

Temporary Access Selection Technology in WIFI Networks

  • Lu, Yang;Tan, Xuezhi;Mo, Yun;Ma, Lin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.8 no.12
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    • pp.4269-4292
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    • 2014
  • Currently, increasing numbers of access points (AP) are being deployed in enterprise offices, campuses and municipal downtowns for flexible Internet connectivity, but most of these access points are idle or redundant most of the time, which causes significant energy waste. Therefore, with respect to power conservation, applying energy efficient strategies in WIFI networks is strongly advocated. One feasible method is dynamically managing network resources, particularly APs, by powering devices on or off. However, when an AP is powered on, the device is initialized through a long boot time, during which period clients cannot be associated with it; therefore, the network performance would be greatly impacted. In this paper, based on a global view of an entire WLAN, we propose an AP selection technology, known as Temporary Access Selection (TAS). The criterion of TAS is a fusion metric consisting of two evaluation indexes which are based on throughput and battery life, respectively. TAS is both service and clients' preference specific through balancing the data rate, battery life and packet size. TAS also works well independently in traditional WLANs in which no energy efficient strategy is deployed. Moreover, this paper demonstrates the feasibility and performance of TAS through experiments and simulations with Network Simulator version 3 (NS3).