• Journal of Institute of Control, Robotics and Systems
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• v.19 no.2
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• pp.152-157
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• 2013

In this paper, we represent the implementation and performance analysis of vector tracking loop based GPS receiver for jamming environment. The vector tracking loop navigation performance is compared by simulation with conventional tracking loop. The simulation results shows that vector tracking loop is more robust than conventional tracking loop in jamming environment. The vector tracking loop can gain 2dB in jamming performance capability over a conventional GPS receiver. Also, Anti-jamming performance of INS Doppler aiding and deep integration method are compared.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.12A
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• pp.1217-1224
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• 2008

The carrier tracking has to be basically completed for accurate positioning of Galileo satellite system. The FLL for tracking frequency errors is robust to dynamic stress causing changes of propagation time but hardly tracks accurate carrier tracking. The PLL for tracking phase errors provides accurate carrier tracking but is sensitive to dynamic stress and its tracking performance is decreased when high dynamics exist. In this paper, we design the carrier tracking loop with the FLL-assisted PLL loop filter and co-operations of FLL and PLL to achieve accurate carrier tracking in high dynamic stress. we prove the performance of designed carrier tracking loop via simulations.

• Journal of Oral Medicine and Pain
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• v.31 no.1
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• pp.37-45
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• 2006

The use of music as a means of inducing positive emotions and subsequent relaxation has been extensively studied by researchers. A great deal of this research has focussed on the use of music as a means of reducing feelings of anxiety and stress as well as aiding in the relief of numerous pathologies. The purpose of this study was to evaluate this effect of music using laser doppler flowmeter that monitors relative changes in the muscular blood cell perfusion, concentration of moving blood cells, mean velocity of the myofascial pain disorder patients. Total of 30 subjects were selected. They were monitored by LDF(Laser Doppler Flowmeter) during music listening for 3 minutes. LDF probe was placed over the temporalis muscle. The obtained results were as follows: 1. The average blood perfusion for 3 minutes of music listening at surface of temporalis muscles were elevated on both affected and unaffected parts compared to rest time. 2. The average of blood perfusion elevated during music listening at surface of temporalis muscles were higher in affected part than unaffected part. 3. Increase of blood perfusion during music listening is proportioin to that before music listening. In summary, these results may encouraging start to the elucidation of the hemodynamic events occuring during music listening and aimed to serve as a base for further studies.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.99-104
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• 2012

The United States will proceed with the effort to modernize the GPS system, and one of its main content is to provide L5 signal. L5 will be transmitted in a radio band reserved exclusively for aviation safety services. And, L5, in combination with L1, will improve the position accuracy via ionospheric correction and robustness via signal redundancy. However, The acquisition processing time of L5 takes longer than that of L1 as the code length of L5 is 10 times longer than that of L1. To reduce this acquisition processing time, a higher number of correlators in the aquisition module should be used. However, there is a problem that this causes increase in the complexity of the correlator configuration and the computation power. So, in this paper, we propose L5 signal tracking scheme using tracking results in the GPS L1/L5 receiver. The proposed scheme could reduce the hardware complexity as the GPS L5 signal acquisition module is not needed, and provide fast and stable tracking of L5 signal by aiding L1 tracking results such as PRN, the code phase synchronization, and the Doppler frequency. The feasibility of the proposed scheme is demonstrated through simulation results.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.676-685
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• 2023

Purpose To investigate the incidence, outcomes, and imaging characteristics of clustered microcysts detected on breast US in asymptomatic women, and suggest appropriate management guidelines. Materials and Methods We identified and reviewed the lesions recorded as "clustered microcysts" on breast US performed in asymptomatic women between August 2014 and December 2019. The final diagnosis was based on pathology and imaging follow-up results for at least 12 months. Results The incidence was 1.5% and 100 patients with 117 lesions were included. Among 117 lesions, 3 (2.6%), 2 (1.7%), and 112 (95.7%) were malignant, high-risk benign, and benign lesions, respectively. The malignant lesions included two cases of ductal carcinoma in situ and one invasive ductal carcinoma. Two of them were assessed as category 4, showing mammographic suspicious microcalcifications and internal vascularity on Doppler US. The remainder was a false negative case and showed echo pattern change on the 12-month follow-up US. Conclusion The incidence of clustered microcysts on breast US in asymptomatic women was 1.5% and malignancy rate was 2.6% (3 of 117). Knowledge of outcomes and imaging features of benign and malignant clustered microcysts may be helpful for radiologists, thereby aiding categorization and management recommendations.