• Smart Structures and Systems
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• v.18 no.5
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• pp.885-909
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• 2016

Advances in low-cost wireless sensing have made instrumentation of large civil infrastructure systems with dense arrays of wireless sensors possible. A critical issue with regard to effective use of the information harvested from these sensors is synchronized sensing. Although a number of synchronization methods have been developed, most provide only clock synchronization. Synchronized sensing requires not only clock synchronization among wireless nodes, but also synchronization of the data. Existing synchronization protocols are generally limited to networks of modest size in which all sensor nodes are within a limited distance from a central base station. The scale of civil infrastructure is often too large to be covered by a single wireless sensor network. Multiple independent networks have been installed, and post-facto synchronization schemes have been developed and applied with some success. In this paper, we present a new approach to achieving synchronized sensing among multiple networks using the Pulse-Per-Second signals from low-cost GPS receivers. The method is implemented and verified on the Imote2 sensor platform using TinyOS to achieve $50{\mu}s$ synchronization accuracy of the measured data for multiple networks. These results demonstrate that the proposed approach is highly-scalable, realizing precise synchronized sensing that is necessary for effective structural health monitoring.

• Journal of Digital Convergence
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• v.18 no.3
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• pp.171-177
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• 2020

Under the influence of the Fourth Industrial Revolution, there are many tries to promote productivity enhancement and competitiveness by adapting smart farm technology that converges ICT technologies in agriculture. This smart farming technology is emerging as a new paradigm for future growth in agriculture. The development of real-time cultivation environment monitoring and automatic control system is needed to implement smart farm. Furthermore, the development of intelligent system that manages cultivation environment using monitoring data of the growth of crops is required. In this paper, a fast and efficient development method for implementing a cloud-based smart farm management system using a highly compatible and scalable web platform is proposed. It was verified that the proposed method using the web platform is effective and stable system implementation through the operation of the actual implementation system.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.5
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• pp.639-650
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• 1999

Generally, a performance management consists of the iterative process of performance monitoring, performance analysis, and performance tuning. In this paper, we describe the design and implementation of performance monitor and performance tuner which can be used on the top of SPAX, also known as TICOM IV. SPAX has a hierarchical structure. All nodes, each of which has a local memory, are connected to the interconnection network and constructed to form clusters. Therefore, it is necessary to develop a new performance monitor reflecting the underlying hierarchical structure of SPAX, to implement performance monitoring more effectively. Implemented performance monitor can monitor the state of nodes, clusters, and total system of SPAX at realtime. And, implemented performance tuner can change the value of variables related to the performance of SPAX. System manager can perform an effective performance management by using the proposed performance management tools.

• Smart Structures and Systems
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• v.5 no.4
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• pp.415-426
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• 2009

This study focuses on the concept of multi-scale wireless sensor networks for damage detection in civil infrastructure systems by first over viewing the general network philosophy and attributes in the areas of data acquisition, data reduction, assessment and decision making. The data acquisition aspect includes a scalable wireless sensor network acquiring acceleration and strain data, triggered using a Restricted Input Network Activation scheme (RINAS) that extends network lifetime and reduces the size of the requisite undamaged reference pool. Major emphasis is given in this study to data reduction and assessment aspects that enable a decentralized approach operating within the hardware and power constraints of wireless sensor networks to avoid issues associated with packet loss, synchronization and latency. After over viewing various models for data reduction, the concept of a data-driven Bivariate Regressive Adaptive INdex (BRAIN) for damage detection is presented. Subsequent examples using experimental and simulated data verify two major hypotheses related to the BRAIN concept: (i) data-driven damage metrics are more robust and reliable than their counterparts and (ii) the use of heterogeneous sensing enhances overall detection capability of such data-driven damage metrics.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.3-9
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• 2008

Recently, the plant industries are being activated and plant control systems use various technologies. Because the optimized design for the plants is very important for the reducing of operation and maintenance costs, automatic control systems become more important. Plant control systems consist of the master controller, the plant networks, the programming environment for engineering, monitoring software and the field devices. The control systems should have reliability, availability and safety. Modular architecture of hardware and software makes flexible configuration of the control systems. Each component should have diagnostic functions. It follows industrial standards and makes open systems. Open systems increase accessibility against the data which is distributed in the plants. The controllers including processor and communication modules use the up-to-date technology. They have real time and fault tolerant function by duplicating processors or networks. It also enables to make the distributed control systems. The distributed architecture makes more scalable main control system. Automatic control systems can be operated with better performance. In this paper, we analyzed the requirements of the seawater desalination plants and made some consideration facts for developing the optimized controller. Also we described the design concept of the main controller, which consists of several modules. We should validate and complement the design for the reliability and better performance.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.2
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• pp.852-857
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• 2011

The shipbuilding industry needs automation and mechanization to solve reduction of skilled workers and labor shortage. Ship manufacturing process is the lack of automation than standardized manufacturing field. In this paper, we design and development an process automation system for hand rail production. Mechanical parts of the cutting process was designed with efficiency, productivity and reliability, CATIA and ANSYS, the stability of the mechanical structure was confirmed. System control using a PCNC controller to provide an open and scalable, and operate using touch-screen display control and monitoring of the system was performed. The automatic system successfully passed the driving test and processing test, and it showed an excellent performance.

• Journal of Information Processing Systems
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• v.13 no.5
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• pp.1299-1319
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• 2017

This paper presents a scalable multiple camera collaboration strategy for active tracking applications in large areas. The proposed approach is based on distributed mechanism but emulates the master-slave mechanism. The master and slave cameras are not designated but adaptively determined depending on the object dynamic and density distribution. Moreover, the number of cameras emulating the master is not fixed. The collaboration among the cameras utilizes global and local sectors in which the visual correspondences among different cameras are determined. The proposed method combines the local information to construct the global information for emulating the master-slave operations. Based on the global information, the load balancing of active tracking operations is performed to maximize active tracking coverage of the highly dynamic objects. The dynamics of all objects visible in the local camera views are estimated for effective coverage scheduling of the cameras. The active tracking synchronization timing information is chosen to maximize the overall monitoring time for general surveillance operations while minimizing the active tracking miss. The real-time simulation result demonstrates the effectiveness of the proposed method.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.440-448
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• 2019

The Internet of Things (IoT) is one of the main enablers for situation awareness needed in accomplishing smart cities. IoT devices, especially for monitoring purposes, have stringent timing requirements which may not be met by cloud computing. This deficiency of cloud computing can be overcome by fog computing for which fog nodes are placed close to IoT devices. Because of low capabilities of fog nodes compared to cloud data centers, fog nodes may not be deployed with all the services required by IoT devices. Thus, in this article, we focus on the issue of fog service placement and present the recent research trends in this issue. Most of the literature on fog service placement deals with determining an appropriate fog node satisfying the various requirements like delay from the perspective of one or more service requests. In this article, we aim to effectively place fog services in accordance with the pre-obtained service demands, which may have been collected during the prior time interval, instead of on-demand service placement for one or more service requests. The concept of the logical fog network is newly presented for the sake of the scalability of fog service placement in a large-scale smart city. The logical fog network is formed in a tree topology rooted at the cloud data center. Based on the logical fog network, a service placement approach is proposed so that services can be placed on fog nodes in a resource-effective way.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.3
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• pp.1141-1163
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• 2019

In an effort to minimize operational expenses and supply users with more scalable services, distributed applications are actually going towards the Cloud. These applications, sent out over multiple environments and machines, are composed by inter-connecting independently developed services and components. The implementation of such programs on the Cloud is difficult and generally carried out either by hand or perhaps by composing personalized scripts. This is extremely error prone plus it has been found that misconfiguration may be the root of huge mistakes. We introduce AutoBot, a flexible platform for modeling, installing and (re)configuring complex distributed cloud-based applications which evolve dynamically in time. AutoBot includes three modules: A simple and new model describing the configuration properties and interdependencies of components; a dynamic protocol for the deployment and configuration ensuring appropriate resolution of these interdependencies; a runtime system that guarantee the proper configuration of the program on many virtual machines and, if necessary, the reconfiguration of the deployed system. This reduces the manual application deployment process that is monotonous and prone to errors. Some validation experiments were conducted on AutoBot in order to ensure that the proposed system works as expected. We also discuss the opportunity of reusing the platform in the transition of applications from Cloud to Fog computing.

• The KIPS Transactions:PartC
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• v.10C no.2
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• pp.171-178
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• 2003

Differentiated Services (DiffServ) is a technique to provide Quality of Service (QoS) in an efficient and scalable way. However, current DiffServ specifications have limitations in providing the complete QoS management framework and its implementation model. This paper proposes a policy-based QoS management model that supports DiffServ policies for managing QoS of DiffServ networks. The management model conforms to Model-View-Controller (MVC) architecture, and is based on Enterprise JavaBeans (EJBs) technologies. In our model, high-level DiffServ QoS policies are represented as valid XML documents with an XML Schema and are translated to low-level EJB policy beans in the EJB-based policy server. The routing topology and role information required to define QoS policies is discovered by using SNMP MIB-II, and the QoS policy distribution and monitoring is accomplished by using SNMP DiffServ MIB.