• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2007.06a
• /
• pp.645-648
• /
• 2007

This paper describes database server management system by mobile device. Our system can control database server immediately in any where by mobile device. We have developed the dataset server CE which interface with mobile device, database management system which rons in mobile device and web services which connect the mobile database with desktop database. External mobile device communicate with web service agent via wireless equipment. Our system includes dataset server CE client engine, web service server agent and mobile device management system. Through the test by an application program, we have confirmed that our system operates very well each others.

• Journal of Advanced Navigation Technology
• /
• v.12 no.2
• /
• pp.109-114
• /
• 2008

As the Ubiquitous times approach, an interest regarding a Ubiquitous sensor network to be the only during key technology is rising. Currently, The fast development which radio communication technique is creating new services from the industry sector which is various from convenient characteristic and the ease characteristic side. Specially, rise and development of the radio communication technique which is various from environment monitor ring field makes to be improved about sharp curtailment of establishment and logistics relation expense, and collection period of the data which occurs real-time from site, reliability and delivery characteristic. But continuous application and the success about the environment monitor ring field of radio communication technique will be able to trust And It is important to provide time information which is appropriate real-time.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.14 no.9
• /
• pp.2057-2064
• /
• 2010

With the development of wireless network technology, the location information of a spatiotemporal object which changes their location is used in various application. Each spatiotemporal object has many location information, hence it is inefficient to search all trajectory information of spatiotemporal objects for a range query. In this paper, we propose an efficient method which divides a trajectory and stores its division data on restricted storage space. Using suboptimal split algorithm, an extended split algorithm that minimizes the volume of EMBRs(Extended Minimum Bounding Box) is designed and simulated. Our experimental evaluation confirms the effectiveness and efficiency of our proposed splitting policy

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.8A
• /
• pp.810-819
• /
• 2010

This paper proposes an algorithm to improve total network lifetime for Wireless Sensor Network (WSN) application such as environmental condition monitoring systems based on LEACH protocol. Firstly, the algorithm had equal number of nodes allocated to each cluster at cluster set-up phase where it abided by LEACH protocol. Secondly, at cluster set-up phase, each node was determined the order to be cluster header of the cluster which it had joined. After then, the role of a cluster head delivers to the next node according to determined order when the cluster head has received certain number of packets. With above method energy consumption of each node made equal and overall network lifetime was increased. Simulation results shows that overall network lifetime of proposed algorithm was increased two times than that of LEACH and total energy consumption was one forth of that of LEACH protocol.

• Korean Journal of Computational Design and Engineering
• /
• v.19 no.2
• /
• pp.157-168
• /
• 2014

In this paper, HSE (Health and Safety Environments) research with smart device and biometrics is conducted for the worker's HSE enhancement in the manufacturing shop floor. Today, various kinds of smart devices are popularized extensively. In addition, the wearable type devices are being introduced such as google glass very recently. Smart device of werable type is exptected to bring great opportunity out in terms of HSE functionality. Smart devices of phone or tablet type are being used for on-line work between control center and manufacturing shop floor by virtue of wireless communication. However, those devices are not appropriate for detecting of worker's physical senses such as temperature and pulse. In this paper, we developed a glass type smart device and required funictions for HSE enhancement with the investigation of biometrics technology. Also, required sensors are investigated for the detecting of temperature, pulse and noxious gasses. Smart device of glass type has advantages in that most senses of personnel are gathered around faces, and also it's possible to detect neutral axis of body because the wearing location is fixed. We expect that the proposing HSE product of glass type smart device could contribute the enhancement of the HSE of manufacturing shop floor.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.3
• /
• pp.465-473
• /
• 2012

In this study, a novel dual band planar monopole antenna for wireless local area network (WLAN)/ Worldwide Interoperability of Microwave Access (WiMAX) application was designed, fabricated, and measured. The proposed antenna consists of two hook shaped strips, an asymmetric ground plane, and a rectangular slit in the ground plane. Acceptable agreements between the measured and simulated results are achieved. Numerical and experimental results demonstrate that the proposed antenna satisfies the 10 dB impedance bandwidth requirement while covering the WLAN and WiMAX bands simultaneously. This paper also presents and discusses the 2D radiation patterns and 3D gains according to the results of the experiment that was conducted.

• Journal of information and communication convergence engineering
• /
• v.2 no.4
• /
• pp.219-223
• /
• 2004

MMS has been seen as the key application in its entry into the 3G mobile markets. Furthermore, the combination of WLAN and 3G wireless technologies will make MMS service more popular, bringing benefits to both service providers and their customers. To realize seamless MMS service over WLAN and CDMA2000 networks, we design and implement new platform architecture by reusing the existing standards and network elements at the same time. We employ loose coupling approach and Mobile IP approach to propose new platform architecture, interfacing MMSC with many existing components. Based on our platform architecture, we also present seamless MMS delivery implementations that can't be possible within the current MMS reference architecture. This paper will make a contribution for service providers to offer their customers with seamless MMS service over WLAN and CDMA2000 networks.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.27 no.1B
• /
• pp.49-55
• /
• 2002

IMT-2000 mobile system will provide many application services such as mobile internet, wireless electronics commerce applications using air interface with high data rate. These applications require high data integrity, data confidentiality, user authentication, user identity confidentiality and non-repudiation. In this study, we analyze new security threats and air interface traffic performance for IMT-2000 mobile systems. Signal traffic for network access security services requires 0.2kbps~4.5kbps with the conditions of 246~768bits/massage, 0.2~1.0 basic services/sec and the security services of the rate 0.2~1.0 times compared with basic services.

• Journal of Construction Engineering and Project Management
• /
• v.6 no.2
• /
• pp.30-39
• /
• 2016

This research presents the development of a self-governing mobile robot navigation system for indoor construction applications. This self-governing robot navigation system integrated robot control units, various positioning techniques including a dead-reckoning system, a UWB platform and motion sensors, with a BIM path planner solution. Various algorithms and error correction methods have been tested for all the employed sensors and other components to improve the positioning and navigation capability of the system. The research demonstrated that the path planner utilizing a BIM model as a navigation site map could effectively extract an efficient path for the robot, and could be executed in a real-time application for construction environments. Several navigation strategies with a mobile robot were tested with various combinations of localization sensors including wheel encoders, sonar/infrared/thermal proximity sensors, motion sensors, a digital compass, and UWB. The system successfully demonstrated the ability to plan an efficient path for robot's movement and properly navigate through the planned path to reach the specified destination in a complex indoor construction site. The findings can be adopted to several potential construction or manufacturing applications such as robotic material delivery, inspection, and onsite security.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.48 no.1
• /
• pp.45-49
• /
• 2011

Cooperative multihop communications support effective transmissions over underwater acoustic channels as inferior wireless channels. But the performance of cooperative multihop systems may degrade due to the lack of cooperative nodes at the initial operation time duration. At the initial time duration, the lack of cooperative nodes causes more errors, and the multihop network propagates these errors. In this paper, we apply fountain code to the cooperative multihop system at the initial time duration, and show performance improvements by simulations.