• Title/Summary/Keyword: Temporal domain

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Ghost-free High Dynamic Range Imaging Based on Brightness Bitmap and Hue-angle Constancy (밝기 비트맵과 색도 일관성을 이용한 무 잔상 High Dynamic Range 영상 생성)

  • Yuan, Xi;Ha, Ho-Gun;Lee, Cheol-Hee;Ha, Yeong-Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.1
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    • pp.111-120
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    • 2015
  • HDR(High dynamic range) imaging is a technique to represent a dynamic range of real world. Exposure fusion is a method to obtain a pseudo-HDR image and it directly fuses multi-exposure images instead of generating the true-HDR image. However, it results ghost artifacts while fusing the multi-exposure images with moving objects. To solve this drawback, temporal consistency assessment is proposed to remove moving objects. Firstly, multi-level threshold bitmap and brightness bitmap are proposed. In addition, hue-angle constancy map between multi-exposure images is proposed for compensating a bitmap. Then, two bitmaps are combined as a temporal weight map. Spatial domain image quality assessment is used to generate a spatial weight map. Finally, two weight maps are applied at each multi-exposure image and combined to get the pseudo-HDR image. In experiments, the proposed method reduces ghost artifacts more than previous methods. The quantitative ghost-free evaluation of the proposed method is also less than others.

StateflowTD - A unified modeling Formalism of Stateflow and Timing Diagram (StateflowTD - Stateflow와 Timing diagram의 통합 모델링 방법론)

  • Lee, Hong-Seok;Chung, Ki-Hyun;Choi, Kyung-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.35 no.12B
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    • pp.1227-1235
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    • 2010
  • Stateflow is a useful system modeling tool, which is frequently used in industry. But Stateflow has defects when users are trying to describe consecutive behaviors or a system's temporal behaviors. Timing diagram, on the other hand, is a widely used tool of explaining behaviors of a hardware system in electronics. This tool has a merit when specifying consecutive behaviors and temporal behaviors of a system. Thus, this paper suggests $Stateflow_{TD}$, the unified modeling methodology in Stateflow domain integrating Stateflow with Timing diagram in order to improve the shortcomings of Stateflow. This paper not only explains a technique of integrating both a Stateflow model and Timing diagram models, and describes advantages of what $Stateflow_{TD}$ formalism has, but also shows its convenience using two example systems.

Development of Agricultural Drought Assessment Approach Using SMAP Soil Moisture Footprints (SMAP 토양수분 이미지를 이용한 농업가뭄 평가 기법 개발)

  • Shin, Yongchul;Lee, Taehwa;Kim, Sangwoo;Lee, Hyun-Woo;Choi, Kyung-Sook;Kim, Jonggun;Lee, Giha
    • Journal of The Korean Society of Agricultural Engineers
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    • v.59 no.1
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    • pp.57-70
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    • 2017
  • In this study, we evaluated daily root zone soil moisture dynamics and agricultural drought using a near-surface soil moisture data assimilation scheme with Soil Moisture Active & Passive (SMAP, $3km{\times}3km$) soil moisture footprints under different hydro-climate conditions. Satellite-based LANDSAT and MODIS image footprints were converted to spatially-distributed soil moisture estimates based on the regression model, and the converted soil moisture distributions were used for assessing uncertainties and applicability of SMAP data at fields. In order to overcome drawbacks of the discontinuity of SMAP data at the spatio-temporal scales, the data assimilation was applied to SMAP for estimating daily soil moisture dynamics at the spatial domain. Then, daily soil moisture values were used to estimate weekly agricultural drought based on the Soil Moisture Deficit Index (SMDI). The Yongdam-dam and Soyan river-dam watersheds were selected for validating our proposed approach. As a results, the MODIS/SMAP soil moisture values were relatively overestimated compared to those of the TDR-based measurements and LANDSAT data. When we applied the data assimilation scheme to SMAP, uncertainties were highly reduced compared to the TDR measurements. The estimated daily root zone soil moisture dynamics and agricultural drought from SMAP showed the variability at the sptio-temporal scales indicating that soil moisture values are influenced by not only the precipitation, but also the land surface characteristics. These findings can be useful for establishing efficient water management plans in hydrology and agricultural drought.

A Study for establishment of soil moisture station in mountain terrain (1): the representative analysis of soil moisture for construction of Cosmic-ray verification system (산악 지형에서의 토양수분 관측소 구축을 위한 연구(1): Cosmic-ray 검증시스템 구축을 위한 토양수분량 대표성 분석 연구)

  • Kim, Kiyoung;Jung, Sungwon;Lee, Yeongil
    • Journal of Korea Water Resources Association
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    • v.52 no.1
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    • pp.51-60
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    • 2019
  • The major purpose of this study is to construct an in-situ soil moisture verification network employing Frequency Domain Reflectometry (FDR) sensors for Cosmic-ray soil moisture observation system operation as well as long-term field-scale soil moisture monitoring. The test bed of Cosmic-ray and FDR verification network system was established at the Sulma Catchment, in connection with the existing instrumentations for integrated data provision of various hydrologic variables. This test bed includes one Cosmic-ray Neutron Probe (CRNP) and ten FDR stations with four different measurement depths (10 cm, 20 cm, 30 cm, and 40 cm) at each station, and has been operating since July 2018. Furthermore, to assess the reliability of the in-situ verification network, the volumetric water content data measured by FDR sensors were compared to those calculated through the core sampling method. The evaluation results of FDR sensors- measured soil moisture against sampling method during the study period indicated a reasonable agreement, with average values of $bias=-0.03m^3/m^3$ and RMSE $0.03m^3/m^3$, revealing that this FDR network is adequate to provide long-term reliable field-scale soil moisture monitoring at Sulmacheon basin. In addition, soil moisture time series observed at all FDR stations during the study period generally respond well to the rainfall events; and at some locations, the characteristics of rainfall water intercepted by canopy were also identified. The Temporal Stability Analysis (TSA) was performed for all FDR stations located within the CRNP footprint at each measurement depth to determine the representative locations for field-average soil moisture at different soil profiles of the verification network. The TSA results showed that superior performances were obtained at FDR 5 for 10 cm depth, FDR 8 for 20 cm depth, FDR2 for 30 cm depth, and FDR1 for 40 cm depth, respectively; demonstrating that those aforementioned stations can be regarded as temporal stable locations to represent field mean soil moisture measurements at their corresponding measurement depths. Although the limit on study duration has been presented, the analysis results of this study can provide useful knowledge on soil moisture variability and stability at the test bed, as well as supporting the utilization of the Cosmic-ray observation system for long-term field-scale soil moisture monitoring.

Autonomic Nervous Properties of Atropine and Glycopyrrolate on Heart Rate Variability during Anesthesia with Ketamine-Xylazine in Dogs (개에서 케타민-자일라진 마취동안 심박변이도에 대한 아트로핀과 글리코피롤레이트의 자율신경적 특성)

  • Park, Woo-Young;Bae, Chun-Sik;Lee, Soo-Han;Park, Woo-Dae
    • Journal of Veterinary Clinics
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    • v.26 no.3
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    • pp.212-219
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    • 2009
  • Anticholinergics, which are commonly given as a pre-anesthetic medication to prevent adverse effects in canine anesthesia, can cause cardiac adverse effects. To determine the effects of atropine and glycopyrrolate on the balance of sympathetic nervous tone and parasympathetic nervous tone of the heart during ketamine anesthesia in beagle dogs, heart rate variability(HRV), duration of anesthesia and behavioral changes were evaluated. There were no significant temporal domain differences between atropine and glycopyrrolate. Concerning the frequency domain component, atropine and glycopyrrolate effects were significantly lower(P<0.05) than the control saline-treated group. However, the root mean square of the interval differences between consecutive R peaks(RMSSD) and the standard deviation of Poincare plot perpendicular to the line-of-identity(SD1) in atropine were significantly decreased(P<0.05) from the baseline value, and the low frequency/high frequency ratio(LF:HF ratio) in glycopyrrolate was significantly increased from baseline value(P<0.05). The change of SD1 agreed with that of the high frequency(HF) in the frequency domain component and also with those of respiratory rate and $SpO_2-R$. Our results prove that glycopyrrolate is more suitable as a pre-anesthetic anticholinergic in ketamine anesthesia of dogs with respect to safety and duration of action.

The Parallelization Effectiveness Analysis of K-DRUM Model (분포형 강우유출모형(K-DRUM)의 병렬화 효과 분석)

  • Chung, Sung-Young;Park, Jin-Hyeog;Hur, Young-Teck;Jung, Kwan-Sue
    • Journal of Korean Society for Geospatial Information Science
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    • v.18 no.4
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    • pp.21-30
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    • 2010
  • In this paper, the parallel distributed rainfall runoff model(K-DRUM) using MPI(Message Passing Interface) technique was developed to solve the problem of calculation time as it is one of the demerits of the distributed model for performing physical and complicated numerical calculations for large scale watersheds. The K-DRUM model which is based on GIS can simulate temporal and spatial distribution of surface flow and sub-surface flow during flood period, and input parameters of ASCII format as pre-process can be extracted using ArcView. The comparison studies were performed with various domain divisions in Namgang Dam watershed in case of typoon 'Ewiniar' at 2006. The numerical simulation using the cluster system was performed to check a parallelization effectiveness increasing the domain divisions from 1 to 25. As a result, the computer memory size reduced and the calculation time was decreased with increase of divided domains. And also, the tool was suggested in order to decreasing the discharge error on each domain connections. The result shows that the calculation and communication times in each domain have to repeats three times at each time steps in order to minimization of discharge error.

Feasibility Study of EEG-based Real-time Brain Activation Monitoring System (뇌파 기반 실시간 뇌활동 모니터링 시스템의 타당성 조사)

  • Chae, Hui-Je;Im, Chang-Hwan;Lee, Seung-Hwan
    • Journal of Biomedical Engineering Research
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    • v.28 no.2
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    • pp.258-264
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    • 2007
  • Spatiotemporal changes of brain rhythmic activity at a certain frequency have been usually monitored in real time using scalp potential maps of multi-channel electroencephalography(EEG) or magnetic field maps of magnetoencephalography(MEG). In the present study, we investigate if it is possible to implement a real-time brain activity monitoring system which can monitor spatiotemporal changes of cortical rhythmic activity on a subject's cortical surface, neither on a sensor plane nor on a standard brain model, with a high temporal resolution. In the suggested system, a frequency domain inverse operator is preliminarily constructed, considering the individual subject's anatomical information, noise level, and sensor configurations. Spectral current power at each cortical vertex is then calculated for the Fourier transforms of successive sections of continuous data, when a single frequency or particular frequency band is given. An offline study which perfectly simulated the suggested system demonstrates that cortical rhythmic source changes can be monitored at the cortical level with a maximal delay time of about 200 ms, when 18 channel EEG data are analyzed under Pentium4 3.4GHz environment. Two sets of artifact-free, eye closed, resting EEG data acquired from a dementia patient and a normal male subject were used to show the feasibility of the suggested system. Factors influencing the computational delay are investigated and possible applications of the system are discussed as well.

Transient Analysis of General Dispersive Media Using Laguerre Functions (라게르 함수를 이용한 일반적인 분산 매질의 시간 영역 해석)

  • Lee, Chang-Hwa;Kwon, Woo-Hyen;Jung, Baek-Ho
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.10
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    • pp.1005-1011
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    • 2011
  • In this paper, we present a marching-on-in-degree(MOD) finite difference method(FDM) based on the Helmholtz wave equation for analyzing transient electromagnetic responses in a general dispersive media. The two issues related to the finite difference approximation of the time derivatives and the time consuming convolution operations are handled analytically using the properties of the Laguerre functions. The basic idea here is that we fit the transient nature of the fields, the flux densities, the permittivity with a finite sum of orthogonal Laguerre functions. Through this novel approach, not only the time variable can be decoupled analytically from the temporal variations but also the final computational form of the equations is transformed from finite difference time-domain(FDTD) to a finite difference formulation through a Galerkin testing. Representative numerical examples are presented for transient wave propagation in general Debye, Drude, and Lorentz dispersive medium.

Molecular and Biochemical Characterization of Opisthorchis viverrini Calreticulin

  • Chaibangyang, Wanlapa;Geadkaew-Krenc, Amornrat;Vichasri-Grams, Suksiri;Tesana, Smarn;Grams, Rudi
    • Parasites, Hosts and Diseases
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    • v.55 no.6
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    • pp.643-652
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    • 2017
  • Calreticulin (CALR), a multifunctional protein thoroughly researched in mammals, comprises N-, P-, and C-domain and has roles in calcium homeostasis, chaperoning, clearance of apoptotic cells, cell adhesion, and also angiogenesis. In this study, the spatial and temporal expression patterns of the Opisthorchis viverrini CALR gene were analyzed, and calcium-binding and chaperoning properties of recombinant O. viverrini CALR (OvCALR) investigated. OvCALR mRNA was detected from the newly excysted juvenile to the mature parasite by RT-PCR while specific antibodies showed a wide distribution of the protein. OvCALR was localized in tegumental cell bodies, testes, ovary, eggs, Mehlis' gland, prostate gland, and vitelline cells of the mature parasite. Recombinant OvCALR showed an in vitro suppressive effect on the thermal aggregation of citrate synthase. The recombinant OvCALR C-domain showed a mobility shift in native gel electrophoresis in the presence of calcium. The results imply that OvCALR has comparable function to the mammalian homolog as a calcium-binding molecular chaperone. Inferred from the observed strong immunostaining of the reproductive tissues, OvCALR should be important for reproduction and might be an interesting target to disrupt parasite fecundity. Transacetylase activity of OvCALR as reported for calreticulin of Haemonchus contortus could not be observed.

A Study of the Characteristics of Input Boundary Conditions for the Prediction of Urban Air Flow based on Fluid Dynamics (유체 역학 기반 도시 기류장 예측을 위한 입력 경계 바람장 특성 연구)

  • Lee, Tae-Jin;Lee, Soon-Hwan;Lee, Hwawoon
    • Journal of Environmental Science International
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    • v.25 no.7
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    • pp.1017-1028
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    • 2016
  • Wind information is one of the major inputs for the prediction of urban air flow using computational fluid dynamic (CFD) models. Therefore, the numerical characteristics of the wind data formed at their mother domains should be clarified to predict the urban air flow more precisely. In this study, the formation characteristics of the wind data in the Seoul region were used as the inlet wind information for a CFD based simulation and were analyzed using numerical weather prediction models for weather research and forecasting (WRF). Because air flow over the central part of the Korean peninsula is often controlled not only by synoptic scale westerly winds but also by the westerly sea breeze induced from the Yellow Sea, the westerly wind often dominates the entire Seoul region. Although simulations of wind speed and air temperature gave results that were slightly high and low, respectively, their temporal variation patterns agreed well with the observations. In the analysis of the vertical cross section, the variation of wind speed along the western boundary of Seoul is simpler in a large domain with the highest horizontal resolution as compared to a small domain with the same resolution. A strong convergence of the sea breeze due to precise topography leads to the simplification of the wind pattern. The same tendency was shown in the average vertical profiles of the wind speed. The difference in the simulated wind pattern of two different domains is greater during the night than in the daytime because of atmospheric stability and topographically induced mesoscale forcing.