Browsing by Author "Jhong, Shun-Yu"

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A Triangular NodeTrix Visualization Interface for Overlapping Social Community Structures of Cyber-Physical-Social Systems in Smart Factories
(2020-01-01)
Lin, Chun-Cheng
;
Deng, Der-Jiunn
;
Jhong, Shun-Yu
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This work proposes a cyber-physical-social system (CPSS) framework for smart factories which associates the social-network-based physical factory circumference with the cyber control through a visualization interface based on NodeTrix. The NodeTrix representation consisting of adjacency matrices and node-link diagrams has been popularly used in social network analysis. Different from previous works on NodeTrix based on square-shaped matrices, the proposed NodeTrix applies triangle-shaped matrices for visualizing overlapping communities to save the displaying space, and a simulated annealing algorithm is used to reduce the crossings among links and communities. In the CPSS for smart factories, working-in-process (WIP) products are categorized according to their attributes, and are placed at different storage locations for later different production processes. By the NodeTrix-based interface for CPSS, when users with different domains and experiences work together to make instant decisions on production and logistics, the physical production environment will be adjusted accordingly and immediately through technological support of Industry 4.0. Through the interface, the information on locations, parameters, and interoperability of WIP products can be visualized and adjusted in time. By comparison with other works, the proposed representation looks promising in displaying social networks for the CPSS with fewer crossings within a smaller screen space.
Drawing Social Networks Using Area-Labeling Rectangular Cartograms
(2012-03-01)
Lin, We Dar
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Jhong, Shun-Yu
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Huang, Weidong
;
Lin, Chun-Cheng
;
工業工程與管理學系
People are linked together by social networks, whose complexity depends upon a lot of factors. To our understanding, most visualization interfaces for social networks have not been designed for reflecting their factors so far. As a result, this paper tries to solve such a problem by rectangular cartogram, which is a kind of geographical visualization interface using rectangles to represent regions in a map. Besides the relative position of each rectangle can reflect actual geographical related positions, one of the main features of rectangular cartograms is to use the area size or the shape of each rectangle to reflect the information of its corresponding region, e.g., the population in that region. This paper proposes a layout approach for rectangular cartograms with area labeling for social networks, in which each region has a minimum-width constraint for accommodating a text label. To satisfy the practical use for social networks, we apply a genetic algorithm to finding the minimum-width area-labeling rectangular cartogram under some constraints. By doing so, we can visualize the labeling text on each rectangle and observe the information represented by its area size or shape at the same time. Furthermore, the proposed approach is applied to visualizing the distribution of the Facebook popularity of an enterprise in Taiwan. From the cartogram, the text label on each region can be read directly and the relation among regions as well as their popularity can be visualized at the same time, so that the enterprise can improve the regions with poor popularity by the help from the regions with high popularity.
Energy-efficient placement and sleep control of relay nodes in heterogeneous small cell networks
(2017-02)
Lin, Chun-Cheng
;
Deng, Der-Jiunn
;
Jhong, Shun-Yu
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Small cell (SC) provides low-power radio access with a relatively smaller coverage range than a macrocell. It has been regarded as a key solution for offloading traffic in the future 5G system. Previous works on energy-efficient placement of base stations (BSs) in cellular networks introduced placement and sleep control of low-power relay stations (RSs) to reduce the total power consumption for downlink transmission from BSs to users. As compared with legacy RSs, SC can serve as an RS with a larger coverage range though consuming a bit more circuit power. Hence, this work additionally considers to deploy small cells (SCs) in a one-dimensional highway cellular network with BSs and legacy RSs, and further models the power consumption minimization problem for placement and sleep control of legacy RSs and SCs in this network. Since the problem is hard to be solved analytically, a genetic algorithm with dynamic operator-selection mechanism is further proposed to resolve this problem. Performance of the proposed algorithm is evaluated via simulation with a practical experimental parameter setting.
Evaluating esthetics for user-sketched layouts of clustered graphs with known clustering information
(2016-12)
Lin, Chun-Cheng
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Huang, Weidong
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Liu, Wan-Yu
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Tanizar, Shierly
;
Jhong, Shun-Yu
This paper aims to empirically analyze the esthetics for user-sketched layouts of clustered graphs with known clustering information. In our experiments, given not only the adjacency list of a clustered graph but also its predefined clustering information, each participant was asked to manually sketch clustered graphs "nicely" from scratch on a tablet system using a stylus. Different from previous works, the main concern in this paper is on which graph drawing esthetics people favor when sketching their own drawings of clustered graphs with known clustering information. Another concern of this paper is on the esthetics of clustered graph layouts employed by participants which include not only characteristics and structures of the final graph layouts but also the behavior of user\'s sketching process (including layout creation and adjustment). By observing all layouts and drawing processes, the drawing strategies which participants applied and the drawing esthetics are analyzed. Results show that most participants were unsurprisingly able to draw graphs with clear presence of bridge edges and clustering cohesiveness; more importantly, to distinguish clusters within the restricted-size tablet screen during the drawing process, some of the participants were still able to make each cluster with fewer edge crossings, more symmetries, and more alignment of grid in a smaller drawing area where the cluster spreads. Our results support that to alleviate user\'s complex drawing tasks, aside from the grid-based editing function suggested by the previous work, graph drawing systems should also provide the clustering information if the structure of the graph to be drawn is known.
Lifetime Enhancement of Dynamic Heterogeneous Wireless Sensor Networks with Energy-Harvesting Sensors
(2017-10-01)
Lin, Chun-Cheng
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Chen, Yung-Chiao
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Chen, Jiann-Liang
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Deng, Der-Jiunn
;
Wang, Shang-Bin
Lifetime enhancement has been the major constraint of developing wireless sensor networks (WSNs). Most of previous related works separately considered dynamics and heterogeneity of WSNs, and did not consider energy-harvesting (EH) sensors, which can absorb natural power (e.g., solar and wind power) to extend lifetime of sensor devices. Therefore, this work investigates the problem of extending the lifetime of dynamic heterogeneous WSNs with EH sensors to enhancing the total WSN lifetime. This problem can be characterized as finding the maximal number of covers each of which is a part of all sensors so that all targets can be monitored by these sensors. Since the case for static WSNs has been shown to be NP-complete, the concerned problem is also NP-complete. Hence, this work first models this problem mathematically, and then proposes a novel harmony search algorithm with multiple populations and local search (HSAML) for this problem with dynamics, heterogeneity, and EH sensors. By simulation, the network lifetime, stability, and executing time of the proposed algorithm are analyzed. From experimental results, the proposed HSAML performs better than the conventional algorithm in terms of average network lifetime for larger-scale problems (i.e., when the number of common and EH sensors is small). In addition, the results confirm that adding EH sensors really helps extend the total WSN lifetime.
Minimizing electromagnetic pollution and power consumption in green heterogeneous small cell network deployment
(2017-12-24)
Lin, Chun-Cheng
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Tsai, Ching-Tsorng
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Deng, Der-Jiunn
;
Tsai, I-Hsin
;
Jhong, Shun-Yu
An enormously increasing number of mobile communications devices and IoT sensors have driven rapid advance in wireless and cellular network technologies. Owing to limited energy resources, 5G technology has been expected to be designed as a 'green' network system. To achieve the requirement of future 'green' 5G networks to serve a huge number of mobile devices, this work investigates the problem of deployment and sleep control of a 'green' heterogeneous cellular network along a highway composed of base stations (BSs), legacy relay stations (RSs), and small cells (SCs), with two objectives: minimizing the energy consumption to decrease the impact of limited energy; as well as minimizing the electromagnet pollution from radiation of the three device types to avoid the potential harm to creatures. For decision variables, the deployment and sleep control of legacy RSs and SCs affect the total power consumption, and their coverage affects the total electromagnet pollution. First, this work creates a mathematical model for the optimization problem, and then proposes a hybrid algorithm of genetic algorithm (GA) and differential evolution (DE) with three local search operators to solve the problem, in which GA and DE can effectively handle discrete and continues decision variables, respectively. Simulation of the concerned green cellular networks verifies performance of the proposed algorithm. (C) 2017 Elsevier B.V. All rights reserved.
Rectangular Cartogram Visualization Interface for Social Networks
(2011)
Jhong, Shun-Yu
;
Lin, Chun-Cheng
;
Liu, Wan-Yu
;
Huang, Weidong
;
工業工程與管理學系
Social networks link people together, among which a lot of factors influences their complexity. To our understanding, so far most visualization interfaces for social networks have not reflected any of their factors. Therefore, this paper tries to solve such a problem by rectangular cartograms, which is a kind of geographical visualization interface using rectnaguls to represent regions in a map. Besides the relative position of each rectangle can reflect the actual geographical related positions, one of the main feastures of rectangular cartograms is that the area size or the shape of each rectangle can reflect the information of its corresponding region, e.g., the population in that region. This paper proposes a layout approaph for rectangular cartograms with area labeling for social networks, in which each region has a minimum-width constraint for accommodating a text label. As a result, this paper applies a genetic algorithm to finding the area-labeling rectangular cartogram with minimum width under some constraints to meet the practical use in social networks. By doing so, we can visualize the labeling text on each rectangle and observe the information represented by its area size or shape at the same time. Furthermore, the proposed approach is applied to visualizing the distribution of the Facebook popularity of an enterprise in Taiwan. From the cartogram, the text label on each region can be read directly and the relation among regions as well as the popularity can be visualized, so that the enterprise can improve the regisons with poor popularity by the help from the regions with high popularity.
Wireless Mesh Router Placement with Constraints of Gateway Positions and QoS
(2015)
Lin, Chun-Cheng
;
Chen, Tung-Huei
;
Jhong, Shun-Yu
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The past studies on router node placement for wireless mesh networks (WMNs) did not consider placement of Internet gateways. Therefore, mesh routers and mesh clients can only communicate locally. The problem in this paper is to maximize both network connectivity and client coverage for the router node placement in WMNs consisting of mesh routers, mesh clients, and Internet gateways, subject to three QoS constraints: delay, relay load, and Internet gateway capacity. By visualizing the placements in previous works, we discover two main drawbacks: overlapping and coverless. To solve them, this paper presents a novel particle swarm optimization approach. Performance of the proposed approach is verified by simulation.