• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.189-196
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• 2011

The main issues of the researches are monitoring environment such as weather or temperature variation and natural accident, and sensor gateways which have mobile device, applications for mobile health care. In this paper, we propose the SFMS(Smart Factory Management System) that can effectively monitor and manage a green smart factory area based on M2M service and smart phone with android OS platform. The proposed system is performed based on the TinyOS-based IEEE 802.15.4 protocol stack. To validate system functionality, we built sensor network environments where were equipped with four application sensors such as Temp/Hum, PIR, door, and camera sensor. We also built and tested the SFMS system to provide a novel model for event detection systems with smart phone.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.5
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• pp.1-11
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• 2008

Wireless Sensor Networks is applied to improvement of life convenience or service like U-City as well as environment pollution, tunnel and structural health monitoring, storm, and earthquake diagnostic system. To increase the usability of sensor data and applicability, mobile devices and their facilities allow the applications of sensor networks to give mobile users and actuators the results of event detection at anytime and anywhere. In this paper, we present MUSNEMO(Multi-sensor centric Ubiquitous Smart sensor NEtwork using Mobile devices) developed system for providing more efficient and valuable information services with a variety of mobile devices and network camera integrated to WSN. Our system is performed based on IEEE 802.15.4 protocol stack. To validate system usability, we built sensor network environments where were equipped with five application sensors such magnetic, photodiode, microphone, motion and vibration. We also built and tested proposed MUSNEMO to provide a novel model for event detection systems with mobile framework.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.1
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• pp.64-72
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• 2009

Previous research on sensor networks mainly focused on efficient transmission of data from sensors to fixed sink nodes. Recently there has been active research on mobile sink nodes, but the re-search of an environment where both fixed sink nodes and mobile sinks are present at the same time is rather scarce. This paper proposes a technique for context gathering by mobile devices with the sink functionality added through fixed sinks under a previously built, cluster based multi hop sensor network environment. To this end, clustering of mobile devices were done based on the fixed sinks of a previously built sensor network, and by using appropriate fixed sinks, context gathering was made possible. By mathematical comparison with TTDD routing protocol, which was proposed for mobile sinks, it was conformed that performance increases in energy with the number of mobile sinks, and with the number of movements by mobile devices.

• Journal of Astronomy and Space Sciences
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• v.18 no.3
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• pp.231-238
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• 2001

A prototype CMOS (complementary metal oxide semiconductor) imaging system has been built and the possibility of applying to the application to astronomical observations has been investigated. The CCD (charge coupled device) image sensor has been the mainstay of image capture and astronomical imaging for the last 30 years, but CMOS devices have shown rapidly increasing success and have been adapted to many commercial imaging systems . Although the photometric performances and system noise of CMOS sensors are lower than that of CCD image sensors, CMOS Imaging system can be used to obtain general image capture for astronomical applications.

• Smart Structures and Systems
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• v.8 no.4
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• pp.343-365
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• 2011

Structural system identification (SSI) is an inverse problem of difficult solution. Currently, difficulties lie in the development of algorithms which can cater to large size problems. In this paper, a parameter estimation technique based on evolutionary strategy is presented to overcome some of the difficulties encountered in using the traditional system identification methods in terms of convergence. In this paper, a non-traditional form of system identification technique employing evolutionary algorithms is proposed. In order to improve the convergence characteristics, it is proposed to employ immune algorithms which are proved to be built with superior diversification mechanism than the conventional evolutionary algorithms and are being used for several practical complex optimisation problems. In order to reduce the number of design variables, domain decomposition methods are used, where the identification process of the entire structure is carried out in multiple stages rather than in single step. The domain decomposition based methods also help in limiting the number of sensors to be employed during dynamic testing of the structure to be identified, as the process of system identification is carried out in multiple stages. A fifteen storey framed structure, truss bridge and 40 m tall microwave tower are considered as a numerical examples to demonstrate the effectiveness of the domain decomposition based structural system identification technique using immune algorithm.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.1
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• pp.12-24
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• 2000

The electro-hydraulic servo winch system built in a automatic tension control equipment was designed with a latent need for an advanced system in fishing operations of the inshore and coastal fishing vessels. In order to keep the constant tension condition of warp under loading, a tension control circuit was added to the servo winch system.The dynamic performance in the open loop behaviour of the designed winch system was investigated and its applicability was tested for various possibilities of load using a load generator especially developed in order to this study.The mechanical characteristics of this system is different from that of a conventional type, that is, the tension, length, line speed and drum revolution can be automatically controlled by the information from various sensors, such as torque, rpm and pressure transducers. from the experiment results, it was verified that the servo winch system has very good output and tracking behaviour for the control input signals in different operating conditions though overshoot of out 8% in the transient characteristics of torque under the load though a overshoot of about 8% in the transient characteristics of torque under the load condition can be observed when the opening of servo valve, adjustable by the input voltage between - 10 V up to 10 V, changed suddenly.Consequently, the improved fishing winch system can be effectively used as the automatic shooting and hauling equipment of low cost for small inshore and coastal fishing vessels which engage in net fishing.

• Smart Structures and Systems
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• v.15 no.3
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• pp.593-608
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• 2015

In many of the industrialized countries an increasing amount of infrastructure is ageing. This has become specifically critical to bridges which are a major asset with respect to keeping an economy alive. Life of this infrastructure is scattering but often little quantifiable information is known with respect to its damage condition. This article describes how a damage tolerance approach used in aviation today may even be applied to civil infrastructure in the sense that operational life can be applied in the context of modern life cycle management. This can be applied for steel structures as a complete process where much of the damage accumulation behavior is known and may even be adopted to concrete structures in principle, where much of the missing knowledge in damage accumulation has to be substituted by enhanced inspection. This enhanced and continuous inspection can be achieved through robotic systems in a first approach as well as built in sensors in the sense of structural health monitoring (SHM).

• Advances in nano research
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• v.5 no.4
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• pp.337-357
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• 2017

Knowledge of thin films mechanical properties is strongly associated to the reliability and the performances of Nano Electro Mechanical Systems (NEMS). In the literature, there are several methods for micro materials characterization. Bulge test is an established nondestructive technique for studying the mechanical properties of thin films. This study improve the performances of NEMS by investigating the mechanical behavior of Nano rectangular thin film (NRTF) made of new material embedded in Nano Electro Mechanical Systems (NEMS) by developing the bulge test technique. The NRTF built from adhesively-bonded layers of basalt fiber reinforced polymer (BFRP) laminate composite materials in Nano size at room temperature and were used for plane-strain bulging. The NRTF is first pre-stressed to ensure that is no initial deflection before applied the loads on NRTF and then clamped between two plates. A differential pressure is applying to a deformation of the laminated composite NRTF. This makes the plane-strain bulge test idea for studying the mechanical behavior of laminated composite NRTF in both the elastic and plastic regimes. An exact solution of governing equations for symmetric cross-ply BFRP laminated composite NRTF was established with taking in-to account the effect of the residual strength from pre-stressed loading. The stress-strain relationship of the BFRP laminated composite NRTF was determined by hydraulic bulging test. The NRTF thickness gradation in different points of hemisphere formed in bulge test was analysed.

• International Journal of High-Rise Buildings
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• v.8 no.2
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• pp.95-100
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• 2019

Whilst most research focuses on the reduction of operative energy use in buildings, the aspect of which (and how many) materials are used is often neglected and poorly explored. However, considering the continuous growth of the global population and the limited availability of resources, it is clear that focusing on operative energy alone is too short-sighted. The tasks lying ahead for architects and engineers cannot be accomplished with conventional methods of construction. With a share of 50-60% of global resource consumption, the building industry has a decisive impact on our environment. If business as usual continues, resources will be significantly depleted in a matter of decades. Therefore, researchers of the University of Stuttgart are investigating the concept of adaptivity as a promising method for saving resources in the built environment. The term adaptivity in the context of building structures was first introduced by Werner Sobek. It describes a method where sensors, actuators and control units are implemented in systems or facades in order to oppose physical impacts in an ideal way. The applicability of this method will be verified on an experimental high-rise building at the University campus in Stuttgart. Thus, this paper describes this innovative research project and depicts the concept of adaptivity in high-rise structures. Furthermore, it gives an overview of potential actuation concepts and the interdisciplinary challenges behind them.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1075-1084
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• 2022

Internet of Things(IoT) has become a key available technology for efficiently implementing device to device(D2D) services in various domains such as smart home, healthcare, smart city, agriculture, energy, logistics, and transportation. A lightweight publish/subscribe(Pub/Sub) messaging protocol not only establishes data dissemination pattern but also supports connectivity between IoT devices and their applications. Also, a Pub/Sub broker is deployed to facilitate data exchange among IoT devices. A scalable edge-based publish/subscribe (Pub/Sub) broker overlay networks support latency-sensitive IoT applications. In this paper, we design a hypercube grid quorum(HGQ) for distributed Pub/Sub systems based IoT applications. In designing HGQ, the network of hypercube structures suitable for the publish/subscribe model is built in the edge layer, and the proposed HGQ is designed by embedding a mesh overlay network in the hypercube. As their applications, we propose an HGQ-based mechansim for dissemination of the data of sensors or the message/event of IoT devices in IoT environments. The performance of HGQ is evaluated by analytical models. As the results, the latency and load balancing of applications based on the distributed Pub/Sub system using HGQ are improved.