• Journal of Information Technology Services
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• v.10 no.1
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• pp.105-116
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• 2011

With recent spotlight on the, uniquitous computing technology, the need for object of indentification and location infrastructure has increased. Such GPS technolgy must utilize IEEE 802.15.4 Zigbee used for existing wireless sensor network infra as a basice element for user's context-awareness in a uniquitous environement, for effectiveness.Such real-time GPS service is provided in the internal environment where the user would actually are and most high-rise buildlings apply. Underthe assumption, the real-time GPS technology is seperated by each floor, and signals do not get transmitted to other floors, the application on one floor within the high-rise buildling was conducted. This study intends to suggest a floor detection algorithm using IEE 802.15.3/Zigbee's RSSI which supports the accuracy within a couple of meters for the user's the movement between the floors in high-rise buildings in a complex environment. It proposes an floor detection algorithm using IEEE 802.15.4/Zigbee's RSSI which provides accuracy within a radius of few meters for the users movement between the floors for real-time location tracking within high-rise building in a cmoplex environment. Furthermore, for more accurate real-time location tracking, it suggests an algorithm for real-time location tracking using IEEE 802.15.4a/Zigbee's CSS technology based on triangulation. Based on the suggested algorithm, it designs a hybrid real-time location tracking service system in a high-rise buildling and test its functions.

• Journal of Information Processing Systems
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• v.10 no.1
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• pp.103-118
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• 2014

Over the last couple of years, traditional VANET (Vehicular Ad Hoc NETwork) evolved into VANET-based clouds. From the VANET standpoint, applications became richer by virtue of the boom in automotive telematics and infotainment technologies. Nevertheless, the research community and industries are concerned about the under-utilization of rich computation, communication, and storage resources in middle and high-end vehicles. This phenomenon became the driving force for the birth of VANET-based clouds. In this paper, we envision a novel application layer of VANET-based clouds based on the cooperation of the moving cars on the road, called CaaS (Cooperation as a Service). CaaS is divided into TIaaS (Traffic Information as a Service), WaaS (Warning as a Service), and IfaaS (Infotainment as a Service). Note, however, that this work focuses only on TIaaS and WaaS. TIaaS provides vehicular nodes, more precisely subscribers, with the fine-grained traffic information constructed by CDM (Cloud Decision Module) as a result of the cooperation of the vehicles on the roads in the form of mobility vectors. On the other hand, WaaS provides subscribers with potential warning messages in case of hazard situations on the road. Communication between the cloud infrastructure and the vehicles is done through GTs (Gateway Terminals), whereas GTs are physically realized through RSUs (Road-Side Units) and vehicles with 4G Internet access. These GTs forward the coarse-grained cooperation from vehicles to cloud and fine-grained traffic information and warnings from cloud to vehicles (subscribers) in a secure, privacy-aware fashion. In our proposed scheme, privacy is conditionally preserved wherein the location and the identity of the cooperators are preserved by leveraging the modified location-based encryption and, in case of any dispute, the node is subject to revocation. To the best of our knowledge, our proposed scheme is the first effort to offshore the extended traffic view construction function and warning messages dissemination function to the cloud.

• KIISE Transactions on Computing Practices
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• v.22 no.8
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• pp.363-368
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• 2016

A storage-based VDI (Virtual Desktop Infrastructure) system has the disadvantage of degraded performance when IOs for the VDI system are concentrated on the storage. The performance of the VDI system decreases rapidly especially, in case of the boot storm wherein all virtual desktops boot simultaneously. In this paper, we propose a main memory-based virtual desktop system managing virtual desktop images on main memory to solve the performance degradation problem including the boot storm. Performance of the main memory-based VDI system is improved by storing the virtual desktop image on the main memory. Also, the virtual desktop images with large size can be stored in the main memory using deduplication technology. Implementation of the proposed VDI system indicated that it has 4 times performance benefit than the storage-based VDI system in case of the boot storm.

• Journal of KIISE:Computing Practices and Letters
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• v.5 no.6
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• pp.758-770
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• 1999

최근 급속한 네트워크 기술의 발달로 이들에 대한 관리의 필요성이 제기되었고 이를 위해 SNMP와 CMIP등과 같은 표준이 등장하여 사용되어 왔다. 그러나 점점 더 다양하고 복잡한 네트워크가 형성되자 이들에 대한 효율적인 관리가 필요하게 되었다. 현재, TMN은 개념에 있어서 보편성 및 가장 일반화된 관리개념이며 최종적으로 도달할 네트워크 관리 개념을 포함하고 있다. CORBA는 분산환경에서 응용프로그램을 쉽게 구현할 수 있는 기반을 제공하고 있다. 따라서 이러한 두 가지 기술을 접목한 CORBA와 TMN을 통합하고자 하는 많은 연구가 진행되고 있다. 본 논문에서는 현재의 CORBA/TMN 통합에 대한 연구를 바탕으로 효율적인 네트워크 통합 관리 구조를 정의하고 TMN의 기능중 Alarm Surveillance를 구조에 맞춰 구현하였다. 구현된 Alarm Surveillance System은 다양한 대리자들로부터 보고되는 여러 형태의 Alarm 정보에 대해, 처리 및 운용자에 대한 보고수행 등을 일관성 있게 처리하고 있는 것을 보여주고 있다. 따라서 제시된 Alarm Surveillance System은 사용자에게 일관성 있는 관리행위를 제공함으로써 다양한 관리구조가 적용된 복잡한 네트워크 관리를 제공할 수 있다. 또한 전체 네트워크로부터 필요한 통계분석을 위한 자료 수집 등의 편의를 제공할 것이다.Abstract Recently, due to the rapid development of network technology, the need for the network management appeared. So two representative standardards, SNMP and CMIP, have been applied to many network management system. But the more complex and vaious network are constructed, the demand for more efficient network management technology grew bigger. Currently, TMN technology is beginning to be widely applied to the management of networks. CORBA has been widely adopted for developing distributed systems in many areas of information technology. CORBA provides the infrastructure for the interoperability of various object-oriented management applications in a distributed environment, and, recently there have been world-wide research for the integration of CORBA within a TMN framework. Many attempts have been made to enable network management using CORBA techonology and some are working on already. This paper defines the architecture for integrated network management based on current CORBA/TMN integration technologies and then presents the design and implementation for alarm surveillance system which was applied to the defined architecture. The prototype implementation was done using IONA orbix. The proposed integrated network management framework will provide users with consistent management operations and ability to manage complex and various networks and to gather statistical data from those networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.2
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• pp.267-276
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• 2009

Nowadays, numerous of valuable internet services are available not only for personal computer but also for mobile appliances in wireless network environment. Therefore, as the amount of contents is increased for those services, the storage limitation on mobile devices has became a significant issue. In this paper, we present a new block-level storage network protocol, iATA (Internet Advanced Technology Attachment) as a solution to the above problem. iATA is designed to transport ATA block-level data and command over the ubiquitous TCP/IP network. With iATA, a mobile appliance is able to access and control the ATA storage devices natively through network from anywhere and at anytime as if the storage devices is attached locally. We describe the concepts, design and diverse consideration of iATA protocol. Based on the benchmark experiments and application exploitation, we strongly believe that iATA as a light-weight protocol is efficient and cost-effective to be used as a storage network protocol on a resource limited device that utilizes common-off-the-shelf storage hardware and existing IP infrastructure.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.198-205
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• 2007

In ubiquitous environment a user can be provided with context-aware services based on his or her current location, time, and atmosphere. LBS(Location-Based Services) play an important role for ubiquitous context-aware computing. Because deployment and maintenance of this specialized equipment is costly, many studies have been conducted on positioning using only wireless equipment under a wireless LAN infrastructure. Because a CPS(Cooperative Positioning System) that uses the RSSI (Received Signal Strength Indicator) between mobile equipments is more accurate than beacon based positioning system, it requires great concentration in its applications. This study investigates the relationship between nodes by analyzing a WiPS (Wireless LAN indoor Positioning System), a similar type of CPS, and proposes a improved WiCOPS-d(Wireless Cooperative Positioning System using node density) to increase performance by determining the convergence adjustment factor based on node density.

• Korean Journal of Remote Sensing
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• v.25 no.4
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• pp.367-374
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• 2009

Recently, new GIS applications such as gee portal and spatial data infrastructure are emerging. These are related to web computing techniques or methodologies based on web 2.0 paradigm, open API of portal, open source GIS, and international GIS standards which are independently on developing. The product of these applications can be realized in the linkage of those components. In this study, a case implementation concerning linkage with Google maps API and open source middleware named Deegree is carried out, and the results are discussed for open source uses in geo portal. Open source middleware supports various levels and types of OGC standards, so that it enables web publishing in the several web standard formats and data exchanges and interoperable uses between external database servers. Also the (unction extensions and the multi tier-based architecture within geo portal for specific purpose are possible.

• Steel and Composite Structures
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• v.33 no.3
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• pp.319-332
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• 2019

This study is aimed to predict the behaviour of channel shear connectors in composite floor systems at different temperatures. For this purpose, a soft computing approach is adopted. Two novel intelligence methods, including an Extreme Learning Machine (ELM) and a Genetic Programming (GP), are developed. In order to generate the required data for the intelligence methods, several push-out tests were conducted on various channel connectors at different temperatures. The dimension of the channel connectors, temperature, and slip are considered as the inputs of the models, and the strength of the connector is predicted as the output. Next, the performance of the ELM and GP is evaluated by developing an Artificial Neural Network (ANN). Finally, the performance of the ELM, GP, and ANN is compared with each other. Results show that ELM is capable of achieving superior performance indices in comparison with GP and ANN in the case of load prediction. Also, it is found that ELM is not only a very fast algorithm but also a more reliable model.

• Smart Structures and Systems
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• v.6 no.5_6
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• pp.561-578
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• 2010

This study proposes a multi-level damage localization strategy to achieve an effective damage detection system for civil infrastructure systems based on wireless sensors. The proposed system is designed for use of distributed computation in a wireless sensor network (WSN). Modal identification is achieved using the frequency-domain decomposition (FDD) method and the peak-picking technique. The ASH (angle-between-string-and-horizon) and AS (axial strain) flexibility-based methods are employed for identifying and localizing damage. Fundamentally, the multi-level damage localization strategy does not activate all of the sensor nodes in the network at once. Instead, relatively few sensors are used to perform coarse-grained damage localization; if damage is detected, only those sensors in the potentially damaged regions are incrementally added to the network to perform finer-grained damage localization. In this way, many nodes are able to remain asleep for part or all of the multi-level interrogations, and thus the total energy cost is reduced considerably. In addition, a novel distributed computing strategy is also proposed to reduce the energy consumed in a sensor node, which distributes modal identification and damage detection tasks across a WSN and only allows small amount of useful intermediate results to be transmitted wirelessly. Computations are first performed on each leaf node independently, and the aggregated information is transmitted to one cluster head in each cluster. A second stage of computations are performed on each cluster head, and the identified operational deflection shapes and natural frequencies are transmitted to the base station of the WSN. The damage indicators are extracted at the base station. The proposed strategy yields a WSN-based SHM system which can effectively and automatically identify and localize damage, and is efficient in energy usage. The proposed strategy is validated using two illustrative numerical simulations and experimental validation is performed using a cantilevered beam.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.6
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• pp.33-41
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• 2018

The idea of the Internet of Things as a platform on the Smart Campus has become increasingly popular. It requires an infrastructure consisting of communication networks, sensor nodes and gateways to connect to the Internet. Each sensor node is responsible for gathering data from the environment. This document outlines a network of wireless sensors on the Internet for the application of Smart Campus monitoring. Wireless sensor network Monitoring have become a complete solution to using a low power implementation and integrated systems. The numerous restrictions however result from the low communication range, the limited computing power, the lack of availability of the network protocol, the lack of programming security and the security failures in the areas of confidentiality, integrity and availability. A new security technique and its functionality for WSNM nodes developed. Development in the research of a secure network and suggestions for avoiding denial of service (DOS) and complexity attacks. These systems if properly implemented can provide an energy efficiency mechanism through pre-allocation and a new key from key management models with a secure routine algorithm.