• Journal of the Korean Professional Engineers Association
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• v.44 no.5
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• pp.42-47
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• 2011

Currently, wireless communication environment in high-rise buildings are limited in the basement and ground floor facilities are not in common use do not part, in case of disaster is difficult for efficient repression. In this paper, wireless communication facilities on the ground floor of the skyscraper by building infrastructure, wireless communications is proposed to eliminate shadows. That the presence of various wireless communication systems, wireless communication system proposed by this paper, TPS laying coaxial cable seals leak, and the propagation shades in place by installing indoor antenna is the solution to eliminate shadows. The wireless communications solutions reveal the advantages and features, a method of constructing the proposed design.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.11
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• pp.97-102
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• 2012

Recently, a wireless sensor network system has been receiving great attention for management of underground facilities. However, traditional wireless communication systems using microwaves in several hundred MHz ~ several GHz experience significant performance degradation in the non-uniform underground environment. In this research, in order to make a robust communication for the underground facilities, we propose a wireless underground sensor system based on magnetic field communication. In 3 meters underground environment including rocks, soils, water, etc.,, our proposed sensor network system has proved fully functional and met its performance specification.

• The KIPS Transactions:PartC
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• v.10C no.3
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• pp.335-344
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• 2003

In accordance with the changes in the wireless communication environment, there has been a great need to satisfy the demand for diverse modes of information exchange. Various types of short-distance wireless communication technology have been developed and studied to meet this demand. Among them, Bluetooth and WLAN which has recently been acclaimed as the standard for short-distance wireless communication, has been the focus of many such studies. However, Bluetooth and WLAN has weaknesses in its security features when its in real services are applied to m-commerce. The purpose of this study is to propose techniques that affinity considers to item that is non-security enemy who is although there is no public secure division direct connection in peculiar environment of radio environment as well as limitation security enemy of short distance radio communication. Propose secure monitoring techniques for straggling device to user center also applying proposed way to Bluetooth and WLAN that are short distance communication representative technology based on item that is security enemy and item that is rain suity enemy.

• Journal of Advanced Navigation Technology
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• v.16 no.1
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• pp.54-61
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• 2012

The WAVE specification, which for the Next-Generation ITS environment is a common title: IEEE 802.11p and IEEE P1609 specifications. These days, there are many activities for researching WAVE specification by release of the IEEE 802.11p specification. The difference between high-speed vehicle environment and the indoor environment, the wireless communication channel mode is that much more severe. Thus, the wireless communication system design, temperature, noise, multipath fading and can degrade the performance of the system points should be fully considered matters of. In this paper, we showed WAVE wireless communication system which based on IEEE 802.11p PHY/MAC design process, and also showed solving process many implementation problems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.9
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• pp.4510-4526
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• 2017

Most available methods of facial gender recognition work well under a constrained situation, but the performances of these methods have decreased significantly when they are implemented under unconstrained environments. In this paper, a method via low-rank and collaborative representation is proposed for facial gender recognition in the wild. Firstly, the low-rank decomposition is applied to the face image to minimize the negative effect caused by various corruptions and dynamical illuminations in an unconstrained environment. And, we employ the collaborative representation to be as the classifier, which using the much weaker $l_2-norm$ sparsity constraint to achieve similar classification results but with significantly lower complexity. The proposed method combines the low-rank and collaborative representation to an organic whole to solve the task of facial gender recognition under unconstrained environments. Extensive experiments on three benchmarks including AR, CAS-PERL and YouTube are conducted to show the effectiveness of the proposed method. Compared with several state-of-the-art algorithms, our method has overwhelming superiority in the aspects of accuracy and robustness.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.22 no.1
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• pp.7-14
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• 2014

This paper deals with recent research cases and directions of Fly-By-Wireless (FBWLS) flight control technology. FBWLS is a new type of flight control system technology with the aim of solving the problems mainly caused by the increasing amount of wires in aircraft to which Fly-By-Wire (FBW) technology applies. Therefore, in FBWLS flight control system the wired communication system is replaced with a wireless communication system. Currently the FBWLS flight control technology is at an initial development stage and thus this paper surveys deals with the cases in the viewpoint of technology feasibility. In this context, this paper analyzes technology that needs further studies to secure the reliability, stability and accuracy to the similar level of the corresponding FBW system. Since the major problems of FBWLS technology are packet losses and time delays so that this paper suggests the research direction of wireless communication protocol selection, optimization of wireless communication network and controller design considered communication environment.

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.261-265
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• 2005

In this paper, we constructed the infrastructure with wireless LAN and Access Point in the indoor environment and implemented the teleoperation. Wireless LAN based teleoperation system is irregular communication delay according to environment condition and occurrence possibility of blackout is very high. In this paper, In case these problem happened, we measured communication delay time by real time, and did mobile robot to control harmoniously through vision and force reflection information. Also, we present obstacle-avoidance mode that mobile robot can travel without collision using direction information in case communication delay time is large. We proved usefulness of presented algorithm through teleoperation experiment to apply presented algorithm.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.5
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• pp.2453-2467
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• 2017

Wireless communication is a telecommunication technology, which enables wireless transmission between the portable devices to provide wireless access in all types of environments. In this research, the measurements and various empirical models are analysed and compared in order to find out a suitable propagation model to provide guidelines for cell planning of wireless communication systems. The measured data was taken in urban region with low vegetation and some trees at 900 MHz frequency band. Path loss models are useful planning tools, which permit the designers of cellular communication to obtain optimal levels for the base station deployment and meeting the expected service level requirements. Outcomes show that these empirical models tend to overestimate the propagation loss. As one of the key outputs, it was observed that the calculations of Weissberger model fit with the measured data in urban environment.

• Journal of electromagnetic engineering and science
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• v.12 no.1
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• pp.77-84
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• 2012

This paper introduces our development of a MIMO-OTA system with simplified configuration. The key element of our proposal is the adoption of an antenna branch-controlled configuration for generating multipath delayed waves. The signal processing is carried out on IF band signal with an FPGA in a fading-emulator-type MIMO-OTA measurement system. The proposed scheme is largely different from available system configurations for the fading simulator method of constructing the OTA test environment. We describe the principle of the proposed scheme, channel model incorporated in the system, basic configuration of the developed system, and its performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.9
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• pp.2100-2106
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• 2015

Recently, we are increasing an interest of the health care from the developing elderly society. The need for the safety standardization is the High-tech industry that the technology of Medical science based on advanced nations with the wireless communication technology. It is urgent matter the chronic disease that is growing the total costs is everyday increased. We consider the standardization of the monitoring the medical examination based on the medical science environment with wireless communication technology. In addition, we make the environment of the powerful nation based on medical / patient care technology for the supporting of the high quality service. In this paper, we focus on description of the relationship that convergence of the medical / patient care science is need the component based on wireless communication technology.