• Title/Summary/Keyword: Short Baseline

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Estimated Position of Sea-Surface Beacon Using DWT/UKF (DWT/UKF를 이용한 수면 BEACON의 위치추정)

  • Yoon, Ba-Da;Yoon, Ha-Neul;Choi, Sung-He;Lee, Jang-Myung
    • Journal of Institute of Control, Robotics and Systems
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    • v.19 no.4
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    • pp.341-348
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    • 2013
  • A location estimation algorithm based on the sea-surface beacon is proposed in this paper. The beacon is utilized to provide ultrasonic signals to the underwater vehicles around the beacon to estimate precise position of underwater vehicles (ROV, AUV, Diver robot), which is named as USBL (Ultra Short Baseline) system. It utilizes GPS and INS data for estimating its position and adopts DWT (Discrete Wavelet Transform) de-noising filter and UKF (Unscented KALMAN Filter) elaborating the position estimation. The beacon system aims at estimating the precise position of underwater vehicle by using USBL to receive the tracking signals. The most important one for the precise position estimation of underwater vehicle is estimating the position of the beacon system precisely. Since the beacon is on the sea-waves, the received GPS signals are noisy and unstable most of times. Therefore, the INS data (gyroscope sensor, accelerometer, magnetic compass) are obtained at the beacon on the sea-surface to compensate for the inaccuracy of the GPS data. The noises in the acceleration data from INS data are reduced by using DWT de-noising filter in this research. Finally the UKF localization system is proposed in this paper and the system performance is verified by real experiments.

Landcover classification by coherence analysis from multi-temporal SAR images (다중시기 SAR 영상자료 긴밀도 분석을 통한 토지피복 분류)

  • Yoon, Bo-Yeol;Kim, Youn-Soo
    • Aerospace Engineering and Technology
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    • v.8 no.1
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    • pp.132-137
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    • 2009
  • This study has regard to classification by using multi-temporal SAR data. Multi-temporal JERS-1 SAR images are used for extract the land cover information and possibility. So far, land cover information extracted by high resolution aerial photo, satellite images, and field survey. This study developed on multi-temporal land cover status monitoring and coherence information mapping can be processing by L band SAR image. From July, 1997 to October, 1998 JERS SAR images (9 scenes) coherence values are analyzed and then extracted land cover information factors, so on. This technique which forms the basis of what is called SAR Interferometry or InSAR for short has also been employed in spaceborne systems. In such systems the separation of the antennas, called the baseline is obtained by utilizing a single antenna in a repeat pass.

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Functional Reconstruction of a Combined Tendocutaneous Defect of the Achilles Using a Segmental Rectus Femoris Myofascial Construct: A Viable Alternative

  • DeFazio, Michael Vincent;Han, Kevin Dong;Evans, Karen Kim
    • Archives of Plastic Surgery
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    • v.41 no.3
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    • pp.285-289
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    • 2014
  • The composite anterolateral thigh flap with vascularized fascia lata has emerged as a workhorse at our institution for complex Achilles defects requiring both tendon and soft tissue reconstruction. Safe elevation of this flap, however, is occasionally challenged by absent or inadequate perforators supplying the anterolateral thigh. When discovered intraoperatively, alternative options derived from the same vascular network can be pursued. We present the case of a 74-year-old male who underwent composite Achilles defect reconstruction using a segmental rectus femoris myofascial free flap. Following graduated rehabilitation, postoperatively, the patient resumed full activity and was able to ambulate on his tip-toes. At 1-year follow-up, active total range of motion of the reconstructed ankle exceeded 85% of the unaffected side, and donor site morbidity was negligible. American Orthopaedic Foot and Ankle Society and Short Form-36 scores improved by 78.8% and 28.8%, respectively, compared to preoperative baseline assessments. Based on our findings, we advocate for use of the combined rectus femoris myofascial free flap as a rescue option for reconstructing composite Achilles tendon/posterior leg defects in the setting of inadequate anterolateral thigh perforators. To our knowledge, this is the first report to describe use of this flap for such an indication.

Effects of Sex Education on Condom Attitudes and Condom Use Intention among Undergraduate Students - Dramaturgical interaction approach - (연극학적 상호작용 모델에 근거한 성교육이 남녀 대학생의 콘돔에 대한 태도와 콘돔사용의향에 미치는 효과)

  • Cho, Eun-Jung
    • Research in Community and Public Health Nursing
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    • v.17 no.2
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    • pp.223-234
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    • 2006
  • Purpose: This study was conducted to identify the effects of sexual health education guided by dramaturgical interaction on condom attitudes and intention to use a condom among undergraduate students. Method: Seventy-one female and 23 male volunteers at a university in D metropolitan city participated in the study with an one group pretest-posttest design. The intervention was implemented for five weeks in October 2003 with a short course including group works to encourage university students' social skills In condom use negotiations and condom purchase by using a dramaturgical interaction model. A confidential questionnaire was administered at baseline and post-intervention, and changes in condom attitudes and intention to use a condom were measured. Result: The self-report of female subjects showed significant positive changes in two out of the five condom attitudes domains, such assailability and effectiveness(p<.001) embarrassment about negotiation and use(p<.05), while male subjects showed no change in each of the condom attitudes domains. No significant difference was found in intention to use a condom after the intervention. Conclusion: Sexual health education planned to encourage social skills in condom use by using the dramaturgical interaction model was found to have positive effects on female university students' condom attitudes. A more rigorously designed trial is needed to develop a comprehensive sexual health promotion programme that targets both cognitive and behavioral changes among sexually active Young adults within community.

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The Health Examinees (HEXA) Study: Rationale, Study Design and Baseline Characteristics

  • Health Examinees (HEXA) Study Group
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.4
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    • pp.1591-1597
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    • 2015
  • Background: Korea has experienced rapid economic development in a very short period of time. A mixture of traditional and modern risk factors coexists and the rapid change in non-genetic factors interacts with genetic constituents. With consideration of these unique aspects of Korean society, a large-scale genomic cohort study-the Health Examinees (HEXA) Study-has been conducted to investigate epidemiologic characteristics, genomic features, and gene-environment interactions of major chronic diseases including cancer in the Korean population. Materials and Methods: Following a standardized study protocol, the subjects were prospectively recruited from 38 health examination centers and training hospitals throughout the country. An interview-based questionnaire survey was conducted to collect information on socio-demographic characteristics, medical history, medication usage, family history, lifestyle factors, diet, physical activity, and reproductive factors for women. Various biological specimens (i.e., plasma, serum, buffy coat, blood cells, genomic DNA, and urine) were collected for biorepository according to the standardized protocol. Skilled medical staff also performed physical examinations. Results: Between 2004 and 2013, a total of 167,169 subjects aged 40-69 years were recruited for the HEXA study. Participants are being followed up utilizing active and passive methods. The first wave of active follow-up began in 2012 and it will be continued until 2015. The principal purpose of passive follow-up is based on data linkages with the National Death Certificate, the National Cancer Registry, and the National Health Insurance Claim data. Conclusions: The HEXA study will render an opportunity to investigate biomarkers of early health index and the chronological changes associated with chronic diseases.

Autonomous Real-time Relative Navigation for Formation Flying Satellites

  • Shim, Sun-Hwa;Park, Sang-Young;Choi, Kyu-Hong
    • Journal of Astronomy and Space Sciences
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    • v.26 no.1
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    • pp.59-74
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    • 2009
  • Relative navigation system is presented using GPS measurements from a single-channel global positioning system (GPS) simulator. The objective of this study is to provide the real-time inter-satellite relative positions as well as absolute positions for two formation flying satellites in low earth orbit. To improve the navigation performance, the absolute states are estimated using ion-free GRAPHIC (group and phase ionospheric correction) pseudo-ranges and the relative states are determined using double differential carrier-phase data and singled-differential C/A code data based on the extended Kalman filter and the unscented Kalman filter. Furthermore, pseudo-relative dynamic model and modified relative measurement model are developed. This modified EKF method prevents non-linearity of the measurement model from degrading precision by applying linearization about absolute navigation solutions not about the priori estimates. The LAMBDA method also has been used to improve the relative navigation performance by fixing ambiguities to integers for precise relative navigation. The software-based simulation has been performed and the steady state accuracies of 1 m and 6 mm ($1{\sigma}$ of 3-dimensional difference errors) are achieved for the absolute and relative navigation using EKF for a short baseline leader/follower formation. In addition, the navigation performances are compared for the EKF and the UKF for 10 hours simulation, and relative position errors are mm-level for the two filters showing the similar trends.

CHANGES IN AUTONOMIC RESPONSES AND JAW MUSCLE ACTIVITY INDUCED BY TOOTH PULP STIMULATION IN THE RAT (쥐의 치수자극에 의해 유발되는 자율신경 반응과 악안면 근육활동의 변화)

  • Yu, Mi-Kyung;Park, Soo-Joung
    • Restorative Dentistry and Endodontics
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    • v.24 no.4
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    • pp.657-665
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    • 1999
  • The effects of application of mustard oil (MO), a small-fiber excitant and inflammatory irritant into the rat maxillary molar tooth pulp on arterial blood pressure and heat race, and electromyographic (EMG) activity of the jaw muscles were assessed in the anesthetized rats. In addition, Evans blue extravasation following pulpal MO application was measured. Application of MO into the tooth pulp produced a significant increase in mean arterial pressure and heat rate which gradually returned to baseline level. Application of MO into the tooth pulp induced a significant and short-lasting increase in EMG activity of digastric masseter and tongue muscle. Application of MO into the tooth pulp significantly increased the plasma extravasation of Evans blue dye. However, Application of mineral oil into the tooth pulp did not produce any significant changes in EMG activity of the digastric, masseter and tongue muscles, mean arterial pressure and heart rate, and plasma extravasation of Evans blue dye. These findings indicate that changes in arterial blood pressure, heart rate, jaw muscle activity and plasma extravasation accompanying noxious tooth pulp stimulation call be utilized as indirect measure of orofacial pain and inflammation.

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Using Light Travel Time Effect to Detect Circumbinary Planets with Ground-Based Telescopes

  • Hinse, Tobias Cornelius
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.109.1-109.1
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    • 2012
  • In the past few years, two-planet circumbinary systems (e.g., HW Vir, NN Ser, DP Leo and HU Aqr) have been detected around short-period eclipsing binaries using ground-based telescopes. The existence of these planets has been inferred by interpreting the O-C variations of the mid-eclipse times. We have tested the orbital stability of these systems and propose to use Light Travel Time Effect (LITE) to detect such circumbinary planets from the ground. We generated synthetically the LITE signal of a two-planet circumbinary system with the aim to apply an analytic LITE model to recover the underlying synthetic system. To mimic a degree of realism inherent to ground-based observations, we added to the synthetic LITE data white noise with a Gaussian distribution and sampled the synthetic LITE signal randomly. We successfully recovered the original system demonstrating that two-planet circumbinary systems can be detected using ground-based telescopes, provided the timing measurements of the mid-eclipses are sufficiently accurate and the observing baseline is long enough to ensure a sufficient coverage of all involved periods. We used HU Aqr as a test system and applied our model to its proposed planetary bodies considering near-circular orbits. We present the results of our calculations and discuss the LITE-detectability of a HU Aqr-like system.

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SIFamide and SIFamide Receptor Define a Novel Neuropeptide Signaling to Promote Sleep in Drosophila

  • Park, Sangjin;Sonn, Jun Young;Oh, Yangkyun;Lim, Chunghun;Choe, Joonho
    • Molecules and Cells
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    • v.37 no.4
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    • pp.295-301
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    • 2014
  • SIFamide receptor (SIFR) is a Drosophila G protein-coupled receptor for the neuropeptide SIFamide (SIFa). Although the sequence and spatial expression of SIFa are evolutionarily conserved among insect species, the physiological function of SIFa/SIFR signaling remains elusive. Here, we provide genetic evidence that SIFa and SIFR promote sleep in Drosophila. Either genetic ablation of SIFa-expressing neurons in the pars intercerebralis (PI) or pan-neuronal depletion of SIFa expression shortened baseline sleep and reduced sleep-bout length, suggesting that it caused sleep fragmentation. Consistently, RNA interference-mediated knockdown of SIFR expression caused short sleep phenotypes as observed in SIFa-ablated or depleted flies. Using a panel of neuron-specific Gal4 drivers, we further mapped SIFR effects to subsets of PI neurons. Taken together, these results reveal a novel physiological role of the neuropeptide SIFa/SIFR pathway to regulate sleep through sleep-promoting neural circuits in the PI of adult fly brains.

How multipath error influences modernized GNSS ambiguity resolution in urban areas

  • Kubo, Nobuaki;Yasuda, Akio
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.2
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    • pp.131-136
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    • 2006
  • Commercial uses of GPS have been growing rapidly with applications for aircraft, ship, and land vehicle navigation as well as for surveying and time keeping. The next generation GPS and Japanese QZS (Quasi Zenith Satellite) will provide three different civil signals. Galileo will also provide several types of civil signals. The availability of the third civil frequency has obvious advantages to instantaneous carrier phase accuracy and ambiguity resolution for centimeter level measurements. This paper discusses the effects of additional new civil signals for the high accuracy positioning in urban areas based on simulation using practical raw data. As for constellation, only GPS and GPS+QZS are considered. For positioning, a short distance baseline is assumed in order to disregard atmosphere effects. In this simulation, mask angle and signal conditions were fixed and ambiguity success rates were compared between different triple frequency combination scenarios. The coefficient of reflection was set randomly from 0.05 to 0.5 and the multipath delay was also set randomly from 5-100 m. Visible satellites and signal strength were determined by raw data collected in Tokyo by car. These simulation results have confirmed that the availability of high accuracy positioning will increase in all scenarios if we use GPS+QZS with triple frequencies.

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