• Title/Summary/Keyword: fixed-intensity

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Adaptive thresholding for eliminating noises in 2-DE image (2차원 전기영동 영상에서 잡영을 제거하기 위한 적응적인 문턱값 결정)

  • Choi, Kwan-Deok;Kim, Mi-Ae;Yoon, Young-Woo
    • Journal of the Institute of Convergence Signal Processing
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    • v.9 no.1
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    • pp.1-9
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    • 2008
  • One of the problems for implementing the spot detection phase in the 2-DE gel image analysis program is the eliminating noises in the image. Remained noises after the preprocessing phase cause the over-segmented regions by the segmentation phase. To identify and exclude the over-segmented background regions, if we use the fixed thresholding method that is choosing an intensity value for the threshold, the spots that is invisible by the eyes but mean a very small amount proteins which have important role in the biological samples could be eliminated. This paper propose an adaptive thresholding method that come from an idea that is got on statistical analysing for the prominences of the peaks. The adaptive thresholding method works as following. Firstly we calculate an average prominence value curve and fit it to exponential function curve, as a result we get parameters for the exponential function. And then we calculate a threshold value by using the parameters and probability distribution of errors. Lastly we apply the threshold value to the region for determining the region is a noise or not. According to the probability distribution of errors, the reliability is 99.85% and we show the correctness of the proposed method by representing experiment results.

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Flow-conditioning of a subsonic wind tunnel to model boundary layer flows

  • Ghazal, Tarek;Chen, Jiaxiang;Aboutabikh, Moustafa;Aboshosha, Haitham;Elgamal, Sameh
    • Wind and Structures
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    • v.30 no.4
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    • pp.339-366
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    • 2020
  • This study aims at modeling boundary layers (BLs) encountered in sparse and built environments (i.e. open, suburban and urban) at the subsonic Wind Tunnel (WT) at Ryerson University (RU). This WT has an insignificant turbulence intensity and requires a flow-conditioning system consisting of turbulence generating elements (i.e., spires, roughness blocks, barriers) to achieve proper turbulent characteristics. This system was developed and validated in the current study in three phases. In phase I, several Computational Fluid Dynamic (CFD) simulations of the tunnel with generating elements were conducted to understand the effect of each element on the flow. This led to a preliminary design of the system, in which horizontal barriers (slats) are added to the spires to introduce turbulence at higher levels of the tunnel. This design was revisited in phase II, to specify slat dimensions leading to target BLs encountered by tall buildings. It was found that rougher BLs require deeper slats and, therefore, two-layer slats (one fixed and one movable) were implemented to provide the required range of slat depth to model most BLs. This system only involves slat movement to change the BL, which is very useful for automatic wind tunnel testing of tall buildings. The system was validated in phase III by conducting experimental wind tunnel testingof the system and comparing the resulting flow field with the target BL fields considering two length scales typically used for wind tunnel testing. A very good match was obtained for all wind field characteristics which confirms accuracy of the system.

Motor Evoked Potentials Study of the Facilitation and Reciprocal Inhibition Induced by Motor Imagination in the Thumb Muscles (무지근육에서 상상의 운동과 연관된 촉진과 억제에 관한 운동 유발 전위 검사)

  • Yang, Hyun Duk;Son, Il Hong;Suk, Seung Han;Lee, Sung Soo
    • Annals of Clinical Neurophysiology
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    • v.5 no.2
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    • pp.187-191
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    • 2003
  • Purpose: MEPs elicited by transmagnetic stimulations of the motor cortex are facilitated by voluntary muscle contraction. We evaluated the effects of the imagination of the movements on latencies of MEPs and reciprocal inhibition by using transmagnetic stimulations. Methods: Twenty two healthy volunteers(eight men and fourteen women) were studied. TMSs were delivered at rest and during imagining abducting or adducting right thumb. A stimulator with a round coil and a fixed intensity of 80% of maximum was used to evoke MEPs. MEPs were evoked by magnetic stimulations over the scalp and cervical spine(C7-T1), and central motor conduction times(CMCT) were calculated by subtracting the latency of compound muscle action potentials(CMAPs) obtained by stimulating over the cervical spine from that obtained by stimulating over the scalp. The motor evoked potentials were recorded from right abductor pollicis brevis muscle(APB) and adductor pollicis muscle(AP) simultaneously. Results: Imagination of abduction resulted in a shortened latency of the CMAPs in APB, and a prolonged latency in AP. Imagination of adduction resulted in a shortened latency in AP, and a prolonged latency in APB. But the imagination caused no significant change in the latency of CMAPs elicited by stimulation over cervical spine. Therefore, the changes of the CMCTs account for these latency changes with imagination of movement. With the imagination of abduction, there are significant reduction of the CMCT's in APB(10.8%) and prolongation in AP(5.8%). On the other hand, with the imagination of adduction, prolongation of the CMCT's in APB(7.3%) and reduction in AP(5.9%) were observed. Conclusion: These findings indicate that imagination of muscle contraction increases the excitability of the human corticospinal system. Reciprocal inhibition may be accountable for the prolonged latency in the antagonist muscle.

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A Study on Face Recognition using Neural Networks and Characteristics Extraction based on Differential Image and DCT (차영상과 DCT 기반 특징 추출과 신경망을 이용한 얼굴 인식에 관한 연구)

  • 임춘환;고낙용;박종안
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.24 no.8B
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    • pp.1549-1557
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    • 1999
  • In this paper, we propose a face recognition algorithm based on the differential image method-DCT This algorithm uses neural networks which is flexible for noise. Using the same condition (same luminous intensity and same distance from the fixed CCD camera to human face), we have captured two images. One doesn't contain human face. The other contains human face. Differential image method is used to separate the second image into face region and background region. After that, we have extracted square area from the face region, which is based on the edge distribution. This square region is used as the characteristics region of human face. It contains the eye bows, the eyes, the nose, and the mouth. After executing DCT for this square region, we have extracted the feature vectors. The feature vectors were normalized and used as the input vectors of the neural network. Simulation results show 100% recognition rate when face images were learned and 92.25% recognition rate when face images weren't learned for 30 persons.

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Development of an Organic Scintillator Sensor for Radiation Dosimetry using Transparent Epoxy Resin and Optical Fiber (투명 에폭시와 광섬유를 이용한 방사선량 측정용 유기섬광체 센서 개발)

  • Park, Chan-Hee;Seo, Bum-Kyoung;Lee, Dong-Gyu;Lee, Kune-Woo
    • Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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    • v.7 no.2
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    • pp.87-92
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    • 2009
  • Remote detecting system for a radiation contamination using a plastic scintillator and an optical fiber was developed. Using a commercially available silica optical fiber and a plastic scintillator, we tested then for a real possibility as a remote monitoring detector. Also, a plastic scintillator was developed by itself, and evaluated as a radiation sensor. The plastic scintillator was made of epoxy resin, a hardener and an organic scintillation material. The mixture rate of the epoxy resin, hardener and organic scintillator was fixed by using their emission spectrum, transmittance, intensity etc. In this study, in order to decrease the light loss of an incomplete connection between an optical fiber and a scintillator, the optical fiber was inserted into the scintillator during the fabrication process. The senor used a plastic optical fiber and was estimated for its detection efficiency by an optic fiber's geometric factor.

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A Novel PV Tracking System Control Considering the Power Loss with Change of Insolation (일사량 변화에 다른 전력손실을 고려한 새로운 태양광 추적 시스템 제어)

  • Park, Ki-Tae;Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.6
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    • pp.89-99
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    • 2008
  • In this paper proposes a novel tacking algorithm regarding the power loss when operating a tracking system for a rapidly changing insolation to improve the power of PV hacking system. The tracking system of sensor method used in a conventional PV power station is unable to exactly track a sun position when lacking in the intensity of radiation and has the problem is malfunction of tracking system by a rapidly changing climatic. The tracking system of program method spends too much energy on the unnecessary operation of tracking system because that is unable to adapt itself to a outside factor of climatic environment. In case of tracking an azimuth and altitude of the sun in realtime, therefore, the actual PV power is less increasing than the power of tracking system fixed a specific position. To reduce the power loss, this pap proposes a novel control algorithm of the tracking system. Also, this paper is analyzed efficiency of traditional solar tracking method and proposed method, prove validity of proposed algorithm through demonstrable study.

The Effects of PZT Ratio and Sr Doping on the Piezoelectric Properties in PZN-PNN-PZT (PZN-PNN-PZT계 압전 조성에서 PZN 함량과 Sr Doping이 압전 특성에 미치는 영향)

  • Choi, Jeoung Sik;Lee, Chang Hyun;Shin, Hyo Soon;Yeo, Dong Hun;Lee, Joon Hyung
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.1
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    • pp.19-23
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    • 2018
  • In a Pb-included piezoelectric composition, $Sr_yPb_{1-y}[(Zn_{1/3}Nb_{2/3})_x-(Ni_{1/3}Nb_{2/3})_{0.2}-(Zr_{0.46}Ti_{0.54})_{0.8-x}]O_3$ was selected in order to attain high piezoelectric properties. According to the PZN ratio (x) and the amount of Sr doping (y), the crystal structure, microstructure and piezoelectric properties were measured and evaluated. In the case of Sr 4 mol% doping, the piezoelectric properties were the highest for a PZN ratio of 0.1. In this condition, the grain size was larger and the intensity was higher. With the PZN ratio fixed and varying the Sr doping, the piezoelectric properties increased until 10 mol% doping and then decreased for over 12 mol% doping. In the case of x=0.1 and y=10 mol%, the best piezoelectric properties were obtained, i.e., $d_{33}=660pC/N$ and $k_p=68.5%$, and these values seem to be related to the grain size and crystal structure.

Effect of Gd-based MR contrast agents on CT attenuation of PET/CT for quantitative PET-MRI study

  • Ko, In OK;Park, Ji Ae;Lee, Won Ho;Lim, Sang Moo;Kim, Kyeong Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.1 no.2
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    • pp.130-136
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    • 2015
  • We evaluate the influence of MR contrast agent on positron emission tomography (PET) image using phantom, animal and human studies. Phantom consisted of 15 solutions with the mixture of various concentrations of Gd-based MR contrast agent and fixed activity of [$^{18}F$]FDG. Animal study was performed using rabbit and two kinds of MR contrast agents. After injecting contrast agent, CT or MRI scanning was performed at 1, 2, 5, 10, and 20 minutes. PET image was obtained using clinical PET/CT scan, and attenuation correction was performed using the all CT images. The values of HU, PET activity and MRI intensity were obtained from ROIs in each phantom and organ regions. In clinical study, patients (n=20) with breast cancer underwent sequential acquisitions of early [$^{18}F$]FDG PET/CT, MRI and delayed PET/CT. In phantom study, as the concentration increased, the CT attenuation and PET activity also increased. However, there was no relationship between the PET activity and the concentration in the clinical dose range of contrast agent. In animal study, change of PET activity was not significant at all time point of CT scan both MR contrast agents. There was no significant change of HU between early and delayed CT, except for kidney. Early and delayed SUV in tumor and liver showed significant increase and decrease, respectively (P<0.05). Under the condition of most clinical study (< 0.2 mM), MR contrast agent did not influence on PET image quantitation.

Global Utopia and Local Anxiety on the Stage of the Korean Musical

  • Choi, Sung Hee
    • Cross-Cultural Studies
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    • v.36
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    • pp.123-147
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    • 2014
  • The purpose of this essay is three-fold: to trace the genealogy of the Korean musical, which ever since its inception in the 1960s has been seeking to modernize Korean theater with Broadway as a constant role model; to investigate how the national and the global conflict and are conflated in the form of the Korean musical in the process of its (dis)identification with Broadway; and to examine how its intercultural translations reveal and reflect the dilemma and ambivalence posed by globalization in our era. Drawing on Richard Dyer's signature article Entertainment and Utopia, I analyze how the Korean musical manifests and conduits competing utopian impulses of Korean/Global audiences. I also attempt to problematize the formulaic notion of Broadway musicalsthe Superior Other!which implies a global hegemony that does not, in fact, exist because the boundary between the global and the local as well as the power dynamics of global culture are not fixed but constantly moving and changing. Today's musical scene in Korea shows interesting reversals from the 1990s, when Korean producers were eager to debut on Broadway and impress American audiences. Korean producers no longer look up to Broadway as a final destination; instead they want to make Seoul a new Broadway. They import Broadway musicals and turn them into Korean shows. The glamor of Broadway is no longer the main attraction of musicals in Korea. What young audiences look for most is the glamor of K-pop idols and utopian feelings of abundance, energy, intensity, transparency and community, which they can experience live in the musical with their favorite stars right in front of their eyes. In conclusion, I delve into the complex dynamics of recent Korean musicals with Thomas Friedman's theory of Globalization 3.0 as reference. The binary formula of Global/America versus Local/Korea cannot be applied to the dynamic and intercultural musical scene of today. Globalization is not a uniform phenomenon but rather a twofold (multifold) process of global domination and dissemination, in which the global and the local conflict and are conflated constantly. As this study tries to illuminate, the Korean musical has evolved in a huge net of interdependences between the global and the local with a range of sources, powers and influences.

Case Study for Preventing Construction Site Fall Accidents (건설현장 추락사고 예방을 위한 사례 연구)

  • Choi, Du Ho
    • Korean Journal of Construction Engineering and Management
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    • v.20 no.6
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    • pp.81-88
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    • 2019
  • Recently, the government has shown a decrease in disaster accidents throughout the industry and construction industry due to various efforts to reduce disasters. However, the fall accidents in the construction industry are not decreasing but increasing. In particular, the fall accident caused by scaffolding is low each year, but the disaster intensity is very high in that it directly leads to the death of workers. Scaffolding working environment in domestic construction industry is very poor. Moreover, scaffold workers in small construction sites are not subject to safety oversight and control. Therefore, this study is the installation and non-installation of the vertical lifeline, which is the most fundamental problem to be prevented during the study, to prevent the fall of the moon scaffold. In addition, it is hoped that it will be a solution for preventing accidents in construction site construction through the identification of various causes of disasters such as rope loosening, rope breaking, and fixed point failure.