• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.365-371
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• 2012

In recent years, researchers have been attracted to clustering methods to improve communication and data transmission in a network. Compared with traditional wireless networks, wireless sensor networks are energy constrained and have lower data rates. The concept of implementing a clustering algorithm in an existing project on gateway relocation is being explored here. Low energy adaptive clustering hierarchy (LEACH) is applied to an existing study on relocating a gateway. The study is further improved by moving the gateway to a specific cluster based on the number or significance of the events detected. The protocol is improved so that each cluster head can communicate with a mobile gateway. The cluster heads are the only nodes that can communicate with the mobile gateway when it (the mobile gateway) is out of the cluster nodes' transmission range. Once the gateway is in range, the nodes will begin their transmission of real-time data. This alleviates the load of the nodes that would be located closest to the gateway if it were static.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.141-144
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• 1998

An L-band omnidirectional circular polarized wave antenna is designed and evaluated for transmitting/receiving of vehicle data. Conventional linear polarized wave antenna can not reveive clearly all of the vehicle data which come from the wide driving test range on account of distortion. To overcome this problem, an omnidirectional circular polarized wave antenna is required for the design, first of all, the characteristics, design principle and theoretical background of circular polarized wave with a little signal loss have been reviewed. The designed antenna characteristics an analysed and compared to the desired ones. Our results demonstrate that the strength of vehicle data is flat enough over the full test range using this new antenna.

• The Research Journal of the Costume Culture
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• v.12 no.6 s.53
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• pp.1045-1059
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• 2004

The purpose of the present study was to investigate the total coordination as determined by personality, appearance-related characteristics. Data were collected through a self-administered questionnaire survey from December 18, 2003 to January 13, 2004 from 650 women living in Seoul in the age range of $20{\sim}35$; 500 were used for the data analysis. Data were analyzed by chi-square analysis, ANOVA, descriptive statistics, cluster analysis and Duncan's multiple range test were used. The results showed significant differences in the total coordination behaviors among the groups divided by personality and appearance-related characteristics. Those who had the independent extrovert personality, egg-shaped face or white skin color were most positive with regards to the extent and behaviors of the total coordination.

• Proceedings of the KSR Conference
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• 2003.10a
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• pp.210-215
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• 2003

Korean High Speed Train (KHST) has been tested on high speed line in JungBu site since it was developed in 2002. The KHST figured 7 cars was modeled for dynamic simulation with Vampire program. and the data acquisition system was used to test successfully the on-line test for proving the dynamic performance of KHST. The comparison between test and simulation results for dynamic behavior of KHST was tried in this paper and it was very difficult because the environmental conditions and running conditions have an effect on the test results and these conditions are unable to be modeled for dynamic analysis. Also the parameters for data acquisition system for test are usually not same to simulation conditions. Therefor, in this paper the acceleration data after filtering with low pass filter below 1Hz were used to compare between test and simulation results because the low frequency range is useful to evaluate the dynamic performance for railway vehicle system, so as steady state curving acceleration. The results show that both are similar in low frequency range.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.529-534
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• 2004

The increasing need and use of 3D GIS particularly in urban areas has produced growing attention on building reconstruction. Nowadays, the use of close-range data for building reconstruction has been intensively emphasized since they can provide higher resolution and more complete coverage than airborne sensory data. We developed a fusion approach for building reconstruction from both points and images. The proposed approach was then applied to reconstructing a building model from real data sets acquired from a large existing building. Based on the experimental results, we assured that the proposed approach cam achieve high resolution and accuracy in building reconstruction. The proposed approach can effectively contribute in developing an operational system producing large urban models for 3D GIS.

• Journal of the Korea Institute of Military Science and Technology
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• v.13 no.3
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• pp.388-396
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• 2010

Generally, flight information is transmitted by voice signal over legacy UHF radio in ground to air communication system. In this paper, we have implemented the transceiver of TDL(tactical data link) which transmits tactical information, such as flight information, using digital signal. For transmitting digital information over radio path, we have designed data modem that is processing CPFSK modulation, and TDMA(Time Division Multiple Access) network for Synchronization among multi user(platform). By simulating aeronautical propagation modeling with the environment of Korea terrain, it is predicted the maximum performance of communication range of the transceiver. As result of the transceiver's aviational boarding test, it is proved that the transceiver of TDL over legacy UHF radio transmits and receives the tactical information in TDMA network within communication range of 160km.

• Publications of The Korean Astronomical Society
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• v.37 no.1
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• pp.1-11
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• 2022

During the course of analysing both single-dish and very long baseline interferometry (VLBI) data obtained from the Korean VLBI Network (KVN), we found a systematic offset between flux density measurements from different antennas. We were able to attribute a majority of the systematic offsets to changes in the "a priori" antenna gains, which were found to have varied up to 10 percent at 22 GHz and up to 30 percent at 43 GHz. Using historical calibrator observations, we present a revised set of gains that may be applied to KVN data taken from 2015 August to 2019 January. Application of the revised gains to the KVN results in a consistency of correlated flux density measurements between the three baselines of approximately five percent. We found that images from the recalibrated data typically have a 50 percent higher dynamic range, with some cases showing an increase of dynamic range of up to a factor of three.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.52-61
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• 1993

Developed in this research is a CAM system for 5-axis NC Machining of sculptured surfaces. We identify problems in generating 5-axis NC data and propose methods of overcoming them. Issues discussed in this paper are: kinematic modelling of NC machines; determination of cutter position (location and orientation); check of machine work-range; linear trajectory plann- ing ; calculation of feedrate number. The proposed system has been implemented in FORTRAN77 on the Personal IRIS EWS, and it also constitutes a module of the CAD/CAM system 'CASSET' developed in KIST CAD/CAM lab.

• Journal of applied mathematics & informatics
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• v.29 no.3_4
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• pp.713-719
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• 2011

The problem of approximation from a set of scattered data arises in a wide range of applied mathematics and scientific applications. In this study, we present a quasi-interpolatory approximation scheme for scattered data approximation problem, which reproduces a certain space of polynomials. The proposed scheme is local in the sense that for an evaluation point, the contribution of a data value to the approximating value is decreasing rapidly as the distance between two data points is increasing.

• Journal of Oral Medicine and Pain
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• v.40 no.3
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• pp.96-101
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• 2015

Purpose: Thermal sensory test as an essential part of quantitative sensory testing (QST) has been recognized as a useful tool in the evaluation of the trigeminal nerve function. Normative data in the orofacial region have been reported but the data on differences in the test site, sex and ethnicity are still insufficient. Thus, this study aimed to investigate the normal range of orofacial thermal QST data in the healthy Korean women, and assess sex difference of thermal perception in the orofacial regions. Methods: Thermal QST was conducted on 20 healthy women participants (mean age, 26.4 years; range, 21 to 34 years). The thermal thresholds (cold detection threshold, CDT; warm detection threshold, WDT; cold pain threshold, CPT; and heat pain threshold, HPT) were measured bilaterally at the 5 trigeminal sites (the forehead, cheek, mentum, lower lip and tongue tip). The normative thermal thresholds of women in the orofacial region were evaluated using one-way ANOVA and compared with the previously reported data from age- and site-matched 30 healthy men (mean age, 26.1 years; range, 23 to 32 years) using two-way ANOVA. One experienced operator performed the tests of both sexes and all tests were done in the same condition except the time variability. Results: Women showed significant site differences for the CDT (p<0.001), WDT (p<0.001), and HPT (p=0.047) in the orofacial region. The CDT (p<0.001) and the CPT (p=0.007) presented significant sex difference unlike the WDT and the HPT. Conclusions: The thermal sensory evaluation in the orofacial region should be considered in the context of site and sex and the normative data in this study could be useful for assessment of the sensory abnormalities in the clinical setting.