• ETRI Journal
• /
• v.37 no.4
• /
• pp.707-716
• /
• 2015

The purpose of a localization system is to estimate the coordinates of the geographic location of a mobile device. The accuracy of wireless localization is influenced by nonline-of-sight (NLOS) errors in wireless sensor networks. In this paper, we present an improved time of arrival (TOA)-based localization method for wireless sensor networks. TOA-based localization estimates the geographic location of a mobile device using the distances between a mobile station (MS) and three or more base stations (BSs). However, each of the NLOS errors along a distance measured from an MS (device) to a BS (device) is different because of dissimilar obstacles in the direct signal path between the two devices. To accurately estimate the geographic location of a mobile device in TOA-based localization, we propose an optimized localization method with a BS selection scheme that selects three measured distances that contain a relatively small number of NLOS errors, in this paper. Performance evaluations are presented, and the experimental results are validated through comparisons of various localization methods with the proposed method.

• 제어로봇시스템학회:학술대회논문집
• /
• 1998.10a
• /
• pp.391-394
• /
• 1998

The man-machine interface Is an important factor in the computer system, and it is thought that line-of-sight (LOS) detection technology will allow significant advances in this field. Techniques for detecting LOS for use in human interfaces have been studied［1]［2］. In earlier studies, however, LOS was detected with a head piece, goggles, or through fixing the position of the head. The limitations imposed by these fixed conditions render them unsuitable far use in interfaces, as they have adverse mental or physical effects on humans. Therefore. they have not been sufficiently developed for practical application. Research on non-contact LOS detection is expected to result in a usable LOS man-machine interface［3］［4］, and the current study is intended to be a step in that direction. The authors used color contact lenses for LOS detection, and applied this new method to a computer interface. The use of color contact lenses simplifies image processing. The algorithm used in this study is sufficiently accurate for practical applications. This technique can be used in input devices, in virtual reality applications, and in human engineering research.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.6
• /
• pp.118-125
• /
• 2011

In this paper, a WCDMA experimental base station is constructed for power management of mobile communication base station and effective isotropic radiated power is determined by using received power of pilot channel measured on the line-of sight. The measurement system was constructed by a experimental base station and a measurement receiver and the common pilot channel (CPICH) power of the base station was measured. Effective isotropic radiated power (EIRP) of the base station obtained by the measurement value considering correction factor for the errors represented the difference of 0.5 dB compared to the established EIRP of the base station.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.14 no.9
• /
• pp.756-765
• /
• 2002

Experimental work was performed on the flow characteristics of R-22 and R-l34a in small diameter tubes. The experimental apparatus was made up of liquid pump, pre-heater, sight-glass, condenser and measurement instruments. The sight-glass for flow pattern observations was located at the outlet of the pre-heater. The experiment was carried out to show the flow characteristics of R-22 and R-l34a. Data were taken with test conditions in the following ranges; the mass flux was ranged from 100 to 1,000 kg/$m^2s$, the saturation temperature was $30^{\circ}C$ and the vapor quality was ranged from 0.1 to 0.9. The main results were summarized as follows; In the flow patterns during evaporation, the annular flow in a 2 mm inner diameter tube occurred at a relatively lower quality and mass velocity, compared to the flow in a 8mm inner diameter tube. The evaporation flow in small diameter tubes has been shown major deviations with the Mandhane, Taitel-Dukler's and Wambs-ganss' flow pattern maps but it was similar to the Dobson's flow pattern map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.26 no.6
• /
• pp.611-616
• /
• 2008

When extracting geo-referenced 3D data from cameras mounted on Mobile Mapping Systems, one of important properties for accuracy of extracted data is the alignment of the relative translation(lever-arm) and rotation(bore-sight) between the coordinate systems of Inertial Measurement Unit(IMU)/Ground Positioning System(GPS) and cameras. Since the conventional method calculates absolute camera orientation using ground control points (GCP), the alignment is determined in one Coordinated System (GPS Coordinated System). It basically require GCP. We proposed a mathematical model for the alignment using the initially uncoupled data of cameras and IMU/GPS without GCPs.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.11
• /
• pp.1000-1008
• /
• 2014

Situation awareness for vehicles and pedestrians is very critical to ensure safety. While on-board sensors or systems can easily detect line-of-sight pedestrians, it is difficult to locate the positions of out-of-sight pedestrians especially with no GPS service. This paper proposes a method for accurate and on-time localization of indoor pedestrians by nearby vehicles. The proposed method is based on mobile ad-hoc networks among vehicles and pedestrians, without relying on infrastructures such as GPS, WiFi AP, and Bluetooth-based systems. Also, this paper develops a genetic algorithm to accurately and promptly locate pedestrians. Finally, simulation results are presented to quantitatively evaluate the proposed method compared to other studies.

• Journal of Korea Game Society
• /
• v.10 no.3
• /
• pp.37-45
• /
• 2010

This study examines the characteristics of screen image of 3D first-person shooting games and the newly created subjectivity by that image. 3D first-person shooting games create immersion by remediating the visual experience in the real world. The construction of subjective perspectives and comparatively clear interface are the important features of 3D first-person shooting games. The subjectivity created by this games' image is different from the subjectivity constructed by suture of film. Gamers have the dominant position of the subject of looking, gaming and narrating, but the narrating position is never permanent nor stable. Because the position has the limited sight of first-person, not the comprehensive sight of third-person.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.6A
• /
• pp.568-576
• /
• 2010

In this paper, we analyze the outage probability of full duplex relay (FDR) with decode-and-forward (DF) protocol is derived under fading channels. The fading channel for source-relay link is assumed to be Rician fading to consider the infrastructured fixed relay with line of sight (LOS) propagation, and the other fading channels are assumed to be Rayleigh fading. Based on this analytical result, we provide the criterion that FDR shows a lower outage probability than HDR to consider the interference problem and the resource efficiency improvement by full duplex (FD) operation. The accuracy of the analysis is confirmed throughout the simulation results.

• Journal of the Korean Institute of Rural Architecture
• /
• v.3 no.2
• /
• pp.57-70
• /
• 2001

The spatial composition of Korean traditional houses is based on the relation of spaces in the background of humanism, society, and composition. According to the analysis of it in this study, we make conclusions as follows; 1) Two compositive axises are formed according to age, sex and status which are the main factors of society and culture in the traditional society. 2) The house of '口-shaped' type in the traditional houses concentrates to the interior. To the exterior, it has the closed and conservative system. The wall in the outside of An-Chae intercepts the sight outward and the extension of space, while the wall in the inside is composed of doors and windows which make the sight and space concentrate to the interior. On the contrary, the doors and windows of Sarang-bang and Nu-maru of Sarang-chae open and extend to the exterior. 3) The spatial composition of the traditional houses is composed of geometrical order system and organic order system.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.2
• /
• pp.315-321
• /
• 2011

Since the MB-OFDM(Multi-Band Orthogonal Frequency Division Multiplexing) is an ultra wideband communication system operated on ISM(Industrial, Scientific and Medical) band, DAA(Detect-And-Avoid) is required for co-existence with the other communication service. In this paper we propose the new detection algorithm based on decision-feedback, which shows faster convergence time and less complexity than previous works. The proposed algorithm detects interference above -20dB in AWGN(Additive White Gaussian Noise) and LOS(Line-Of-Sight) channel, and close to AWGN in non-LOS channel under appropriate channel clipping.