• Title/Summary/Keyword: position-domain

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Online correction of drift in structural identification using artificial white noise observations and an unscented Kalman Filter

  • Chatzi, Eleni N.;Fuggini, Clemente
    • Smart Structures and Systems
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    • v.16 no.2
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    • pp.295-328
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    • 2015
  • In recent years the monitoring of structural behavior through acquisition of vibrational data has become common practice. In addition, recent advances in sensor development have made the collection of diverse dynamic information feasible. Other than the commonly collected acceleration information, Global Position System (GPS) receivers and non-contact, optical techniques have also allowed for the synchronous collection of highly accurate displacement data. The fusion of this heterogeneous information is crucial for the successful monitoring and control of structural systems especially when aiming at real-time estimation. This task is not a straightforward one as measurements are inevitably corrupted with some percentage of noise, often leading to imprecise estimation. Quite commonly, the presence of noise in acceleration signals results in drifting estimates of displacement states, as a result of numerical integration. In this study, a new approach based on a time domain identification method, namely the Unscented Kalman Filter (UKF), is proposed for correcting the "drift effect" in displacement or rotation estimates in an online manner, i.e., on the fly as data is attained. The method relies on the introduction of artificial white noise (WN) observations into the filter equations, which is shown to achieve an online correction of the drift issue, thus yielding highly accurate motion data. The proposed approach is demonstrated for two cases; firstly, the illustrative example of a single degree of freedom linear oscillator is examined, where availability of acceleration measurements is exclusively assumed. Secondly, a field inspired implementation is presented for the torsional identification of a tall tower structure, where acceleration measurements are obtained at a high sampling rate and non-collocated GPS displacement measurements are assumed available at a lower sampling rate. A multi-rate Kalman Filter is incorporated into the analysis in order to successfully fuse data sampled at different rates.

Comparative Study of the Symbol Rate Detection of Unknown Digital Communication Signals (미상 디지털 통신 신호의 심볼율 검출 방식 비교)

  • Joo, Se-Joon;Hong, Een-Kee
    • Journal of Advanced Navigation Technology
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    • v.7 no.2
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    • pp.141-148
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    • 2003
  • This paper presents and compares several techniques that detect the symbol rate of unknown received signal. Symbol rate is detected from the power spectral density of the circuits such as the delay and multiplier circuit, the square law circuit, and analytic signal, etc. As a result of discrete Fourier transform of the output signals of these circuits, a lot of spectral lines and some peaks appear in frequency domain and the position of first peak is corresponding to the symbol rate. If a spectral line on the frequency that is not located in symbol rate is larger than the first peak, the symbol rate is erroneously detected. Thus, the ratio between the value of first peak and the highest side spectral line is used for the measure of the performance of symbol rate detector. For the MPSK modulation, the analytic signal method shows better performance than the delay and multiplier and square law circuits when the received signal power is lager than -20dB. It is also noted that the delay and multiplier circuit is not able to detect the symbol rate for the QAM modulation.

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A Study on the Sasang Constitutional Symptom of Taeumin by Voice Characteristics (음향특성에 따른 태음인 체질병증(體質病證) 연구(硏究))

  • Kim, Dal-Rae
    • Journal of Sasang Constitutional Medicine
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    • v.19 no.1
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    • pp.90-97
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    • 2007
  • 1. Objectives and Methods This study was done to investigate the relationships of Sound parameters between Liver Heat Symptom and Esophagus Symptom of Taeumin using PSSC(Phonetic System of Sasang Constitution) in a sentence. Experimental Participants were 20 Korean adult males including, each 10 Liver Heat Symptom and Esophagus Symptom of Taeumin. 2. Results In Pitch segment, APQ segment and Shimmer segment, there were no significant differences between Liver Heat Symptom and Esophagus Symptom of Taeumin. In Octave segment, there were significant differences in Octave 1, Octave 3, Octave 4, Octave 6 of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. In Energy segment, FreQ Domain Total Sum / cnt(0), 0k-2k Total Sum,0k-2k sum dev., 2k-4k Total Sum, 2k-4k sum dev., A# Tot E, B__TOT_E, C__TOT_E, C# Tot E, D__TOT_E, A sum dev., A# sum dev., B sum dev., C sum dev., C# sum dev., Dsum dev., D# sum dev., E sum dev., F sum dev., F# sum dev., G sum dev., G# sum dev. of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. In Voice Recording time segment, Total Voice Recording Time, Voice Recording Time, Divide By Time3, Divide By Energy10, Total Unit, Max Unit Position, U_0 TO 3 of Liver Heat Symptom of Taeumin were significantly high compared with Esophagus Symptom of Taeumin. 3. Conclusion From above result, there is the postbility of efficiency quide constitutional sx. of Taeumin by Voice characteristics. More Soeumin, Soyangin and Taeyangin Symptoms are needed to determine Sasang Constitution using PSSC and to make PSSC effective.

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Sulfonylurea Herbicide Resistance Mechanism of Some Acetohydroxy Acid Synthase Mutants and New Designed Herbicides Specific to the Mutants

  • Choe, Mun Myong;Kang, Hun Chol;Kim, In Chul;Li, Hai Su;Wu, Ming Gen;Lee, Im Shik
    • Weed & Turfgrass Science
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    • v.6 no.1
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    • pp.28-31
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    • 2017
  • The mutation rate of proline in the position 197 (Pro197) in acetohydroxy acid synthase (AHAS) is highest among sulfonylurea (SU) herbicide-resistance mutants. Therefore, it is significant to investigate the resistance mechanism for the mutation and to develop the herbicides specific to the mutants. SU herbicide resistance mechanism of the mutants, 197Ser, 197Thr and 197Ala, in AHAS were targeted for designing new SU-herbicide. We did molecular dynamics (MD) simulation for understanding SU herbicide-resistance mechanisms of AHAS mutants and designed new herbicides with docking and MD evaluations. We have found that mutation to 197Ala and 197Ser enlarged the entrance of the active site, while 197Thr contracted. Map of the root mean square derivation (RMSD) and radius gyrations (Rg) revealed the domain indicating the conformations for herbicide resistant. Based on the enlarging-contracting mechanism of active site entrance, we designed new herbicides with substitution at the heterocyclic moiety of a SU herbicide for the complementary binding to the changed active site entrances of mutants, and designed new herbicides. We confirmed that our screened new herbicides bonded to both AHAS wild type and mutants with higher affinity, showing more stable binding conformation than the existing herbicides.

Perception and Practice of Hospital Infection Control of Nursing Staff depending on the Supplementation of Nurses in Long-term Care Hospitals (간호사 확보에 따른 노인요양병원 간호인력의 병원감염관리 인지도 및 실천도)

  • Lee, Ji-Hyean;Lee, Ga Eon
    • Korean Journal of Occupational Health Nursing
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    • v.21 no.3
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    • pp.308-316
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    • 2012
  • Purpose: The purpose of this study was to describe the perception and practice of hospital infection control of nursing staff in long-term care hospitals by the level of supplementation of nurses. Methods: The participants were 212 nurses and nurse assistants in 13 long-term care hospitals in a metropolitan city and the data were gathered by self-reported questionnaires during August 2011 and analyzed by SPSS/WIN program. Results: The beds per a nurse were 15, and the proportion of nurses among nursing staff in long-term care hospitals was about 33%. In general, the level of infection control in practice was lower than that of perception. The highest perception and practice domain was 'Management of disinfection/contamination', and the lower level domains were 'Personal hygiene' and 'Hand washing' There were statistically significant differences in the hospital infection control of perception and practice depending on age, education, career in long-term care hospital, job position, the quantity of beds, nurse, and nurse assistant, beds per a nurse and proportion of nurses in hospitals. Conclusion: According to these results, the systematic and continual education on hospital infection control of the nursing staff in long-term hospitals should be carried out. In addition, the policy to add more nurses into long-term care hospitals must be implemented.

A Design of semantic web-based fish drug information system (시맨틱 웹기반 수산용 의약품 정보시스템 설계)

  • Ceong, Hee-Taek;Kim, Hae-Ran;Han, Soon-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.1
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    • pp.145-155
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    • 2010
  • In this paper, we suggest a fish drug domain ontology to show an associated information and hierarchy together through concept-relation and inference mechanism instead of keyword matching. First, we investigate competency questions from workers of fishery industry and then we derive concepts and terminologies. Next, we present a process of fish drug ontology modelling using Protege-OWL editor, which is an extension of Protege that supports the Web Ontology Language(OWL). Last, we suggest the user interface of semantic web-based fish drug information system to search easily associated informations of fish drug using this ontology. It is to provide an effective search method that fish disease manager, fish farmer, and students majoring in fisheries can confirm details of diseases, fish, and drug evaluations associated with fish drug within one screen without moving to another position.

Synchrotron SAXS Study on the Micro-Phase Separation Kinetics of Segmented Block Copolymer

  • Lee, Han-Sup;Yoo, So-Ra;Seo, Seung-Won
    • Fibers and Polymers
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    • v.2 no.2
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    • pp.98-107
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    • 2001
  • The phase transition behavior isothermal micro-phase separation kinetics of polyester-based thermoplastic elastomer were studied using the synchrotron X-ray scattering(SAXS) method. The structural changes occurring during heating period were investigated by determining the changes of the one-dimensional correlation function, interfacial thickness and Porod constant. Based on the abrupt increases of the domain spacing and interfacial thickness, a major structural change occurring well below the melting transition temperature is suggested. Those changes are explained in terms of melting of the thermodynamically unstable hard domains or/and the interdiffusion of the hard and soft segments in the interfacial regions. SAXS profile changes during the micro-phase separation process were also clearly observed at various temperatures and the separation rate was found to be sensitively affected by the temperature. The peak position of maximum scattering intensity stayed constant during the entire course of the phase separation process. The scattering data during the isothermal phase separation process was interpreted with the Cahn-Hilliard diffusion equation. The experimental data obtained during the early stage of the phase separation seems to satisfy the Cahn-Hilliard spinodal mechanism. The transition temperature obtained from the extrapolation of the diffusion coefficient to zero value turned out to be about 147$\pm$$2^{\circ}$, which is close to the order-disorder transition temperature obtained from the Porod analysis. The transition temperature was also estimated from the inveriant growth rate. By extrapolating the inveriant growth rate to zero, a transition temperature of about 145$\pm$$\pm$$2^{\circ}$ was obtained.

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High Performance Lossless Data Embedding Using a Moving Window (움직이는 창을 이용한 고성능 무손실 데이터 삽입 방법)

  • Kang, Ji-Hong;Jin, Honglin;Choe, Yoon-Sik
    • Journal of Broadcast Engineering
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    • v.16 no.5
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    • pp.801-810
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    • 2011
  • This paper proposes a new lossless data embedding algorithm on spatial domain of digital images. A single key parameter is required to embed and extract data in the algorithm instead of embedding any additional information such as the location map. A $3{\times}3$ window slides over the cover image by one pixel unit, and one bit can be embedded at each position of the window. So, the ideal embedding capacity equals to the number of pixels in an image. For further increase of embedding capacity, new weight parameters for the estimation of embedding target pixels have been used. As a result, significant increase in embedding capacity and better quality of the message-embedded image in high capacity embedding have been achieved. This algorithm is verified with simulations.

Image Tracking Based Lane Departure Warning and Forward Collision Warning Methods for Commercial Automotive Vehicle (이미지 트래킹 기반 상용차용 차선 이탈 및 전방 추돌 경고 방법)

  • Kim, Kwang Soo;Lee, Ju Hyoung;Kim, Su Kwol;Bae, Myung Won;Lee, Deok Jin
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.39 no.2
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    • pp.235-240
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    • 2015
  • Active Safety system is requested on the market of the medium and heavy duty commercial vehicle over 4.5ton beside the market of passenger car with advancement of the digital equipment proportionally. Unlike the passenger car, the mounting position of camera in case of the medium and heavy duty commercial vehicle is relatively high, it is disadvantaged conditions for lane recognition in contradiction to passenger car. In this work, we show the method of lane recognition through the Sobel edge, based on the spatial domain processing, Hough transform and color conversion correction. Also we suggest the low error method of front vehicles recognition in order to reduce the detection error through Haar-like, Adaboost, SVM and Template matching, etc., which are the object recognition methods by frontal camera vision. It is verified that the reliability over 98% on lane recognition is obtained through the vehicle test.

Integrative Modeling of Wireless RF Links for Train-to-Wayside Communication in Railway Tunnel

  • Pu, Shi;Hao, Jian-Hong
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.2
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    • pp.19-27
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    • 2012
  • In railway tunnel environment, the reliability of a high-data-rate and real-time train-to-wayside communication should be maintained especially when high-speed train moves along the track. In China and Europe, the communication frequency around 900 MHz is widely used for railway applications. At this carrier frequency band, both of the solutions based on continuously laid leaky coaxial cable (LCX) and discretely installed base-station antennas (BSAs), are applied in tunnel radio coverage. Many available works have concentrated on the radio-wave propagation in tunnels by different kinds of prediction models. Most of them solve this problem as natural propagation in a relatively large hollow waveguide, by neglecting the transmitting/receiving (Tx/Rx) components. However, within such confined areas like railway tunnels especially loaded with train, the complex communication environment becomes an important factor that would affect the quality of the signal transmission. This paper will apply a full-wave numerical method to this case, for considering the BSA or LCX, train antennas and their interacted environments, such as the locomotive body, overhead line for power supply, locomotive pantograph, steel rails, ballastless track, tunnel walls, etc.. Involving finite-difference time-domain (FDTD) method and uni-axial anisotropic perfectly matched layer (UPML) technique, the entire wireless RF downlinks of BSA and LCX to tunnel space to train antenna are precisely modeled (so-called integrative modeling technique, IMT). When exciting the BSA and LCX separately, the field distributions of some cross-sections in a rectangular tunnel are presented. It can be found that the influence of the locomotive body and other tunnel environments is very significant. The field coverage on the locomotive roof plane where the train antennas mounted, seems more homogenous when the side-laying position of the BSA or LCX is much higher. Also, much smoother field coverage solution is achieved by choosing LCX for its characteristic of more homogenous electromagnetic wave radiation.