• Title/Summary/Keyword: 신호원

Search Result 2,393, Processing Time 0.033 seconds

Experimental Study on Temperature-Moisture Combined Measurement System for Slope Failure Monitoring (사면붕괴 모니터링에 사용되는 온도-함수비 복합계측시스템 개발에 관한 실험적 연구)

  • Nam, Jin-Won
    • Journal of the Korea institute for structural maintenance and inspection
    • /
    • v.19 no.2
    • /
    • pp.33-39
    • /
    • 2015
  • Recently, the event of slope failure has been occurring frequently due to rapid climate changes and broad development of infrastructures, and the research for establishment of monitoring and prevention system has been an attentive issue. The major influence factors of slope failure mechanism can be considered moisture and temperature in soil, and the slope failure can be monitored and predicted through the trend of moisture-temperature change. Therefore, the combined sensing technology for the continuous measurement of moisture-temperature with different soil depths is needed for the slope monitoring system. The various independent sensors for each item (i.e. temperature and moisture respectively) have been developed, however, the research for development of combined sensing system has been hardly carried out. In this study, the high-fidelity sensor combing temperature-moisture measurement by using the minimized current consuming temperature circuit and the microwave emission moisture sensor is developed and applied on the slope failure monitoring system. The feasibility of developed monitoring system is verified by various experimental approaches such as standard performance test, mockup test and long-term field test. As a result, the developed temperature-moisture combined measurement system is verified to be measuring and monitoring the temperature and moisture in soil accurately.

Immune-stimulatory Effects of Fomes fomentarius Extract in Murine Macrophages (말굽버섯 추출물의 대식세포 면역반응 증강 효과)

  • Kim, Young Hoon;Park, Eun Gyu;Batsuren, Dulamjav;Ganbaatar, Jamsranjav;Nho, Chu Won;Pan, Cheol-Ho;Lee, Jae Kwon
    • Journal of Applied Biological Chemistry
    • /
    • v.57 no.4
    • /
    • pp.373-377
    • /
    • 2014
  • In this study, we demonstrated whether the extract of Fomes fomentarius (FFE; FF extract) could be used to stimulate macrophages (RAW 264.7 cells). All four doses of FFE (5, 10, 20, and $40{\mu}g/mL$) had no significant cytotoxicity during the entire experimental period. FFE potently increased the production of nitric oxide (NO). Consistent with these observations, inducible NO synthase levels were increased by FFE in a dose-dependent manner. Moreover, FFE increased the production of tumor necrosis factor-${\alpha}$, interleukin (IL)-$1{\beta}$, and IL-6 in the same cells. These stimulating effects of FFE were found to be caused by the stimulation of phosphorylation of $I{\kappa}B{\alpha}$ and MAP kinases (p38, ERK, and JNK). These results suggest that FFE may be used as new agents for wide application in the immune study of mushroom.

Dynamic Spectrum Sensing and Channel Access Mechanism in Frequency Hopping Based Cognitive Radio Ad-hoc Networks (주파수 홉핑 기반 인지무선 애드 혹 네트워크에서 동적 스펙트럼 센싱 및 채널 엑세스 방안)

  • Won, Jong-Min;Yoo, Sang-Jo;Seo, Myunghwan;Cho, Hyung-Weon
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.11
    • /
    • pp.2305-2315
    • /
    • 2015
  • Frequency resource value is growing more and more with the development of the wireless communication. With the advent of the current information society comes a serious shortage of frequency resource, as the amount of supply is far from meeting its demands. Thus, cognitive radio (CR) technique is receiving more attention as a way to make use of the temporarily unoccupied frequency resource. In this paper we propose a novel out-of-band spectrum sensing and dynamic channel access scheme for frequency hopping-based cognitive radio ad-hoc networks. At the beginning of each current channel hopping time, member nodes perform spectrum sensing for the next hopping channel. Based on the proposed collision free primary detection notification, member nodes can determine whether they should execute a hopping time extension procedure of the current channel or not. When the primary detected hopping channel is re-idled, the hopping pattern recovery procedure is performed. In this paper we evaluated the performance of the proposed dynamic sensing and hopping channel extension mechanism for the various wireless network conditions. As a result, we show that the proposed method can increase channel utilization and provide reliable channel management operation.

Clinical Analysis of 51 Cases of Free Flap Reconstruction after Ablative Surgery of Head and Neck Cancer (두경부암종 수술 후 결손부위 재건에 사용된 유리피판술 51예의 고찰)

  • Lee, Seung-Won;Kim, Jae-Wook;Kim, Yong-Bae;Tak, Min-Sung;Shi, Ho-Sung;Chang, Hyuck-Soon;Oh, Cheon-Hwan;Park, Jin-Gyu;Koh, Yoon-Woo
    • Korean Journal of Head & Neck Oncology
    • /
    • v.23 no.1
    • /
    • pp.26-31
    • /
    • 2007
  • Background and Objectives:Microvascular free flap reconstruction has been revolutionized in last two decades, and became a standard option in the reconstruction of head and neck defects. We intended to review our experiences of 51 microvascular free flap for head and neck defects during 5-year period and to analyze the types of flaps according to primary sites, success and complication rates. Subjects and Methods:From Oct. 2001 through Dec. 2005, fifty one free flap reconstructions were performed in forty nine patients at ENT department of Soonchunhyang university bucheon hospital. Primary sites, pathology, T-stage, operative time, time interval of oral feeding, and various reconstructive factors such as recipient and donor vessels, free flap related complications, failure rates and salvage rates were retrospectively analyzed. The relation between complication rates and preoperative risk factors were statistically analyzed. Results:Methods of reconstruction were radial forearm free flap(RFFF)(n=28, 54.9%), anterolateral thigh free flaps(n=9, ALTFF)(17.6%), rectus abdominis free flap(n=7, RAFF)(13.7%), jejunal free flap(n=5, JFF)(9.8%), and miscellanous(n=2, 4.0%) in order. In free flap related complications, failure of free flap occurred in seven cases(13.7%) and pharyngocutaneous fistula occurred in five cases(9.8%) among fifty one free flaps. The overall success rate of free flaps was 86.3%. Salvage of free flaps was possible only one among eight cases(12.5%). In positive preoperative risk factor groups, failure of free flap was higher than in negative risk factor group. However, it was not statistically significant. Conclusion:We confirmed that free flap reconstructions are highly versatile and reliable options for use in the reconstruction of various soft tissue defects of the head and neck. Free flaps have gained great popularity given its versatility, ability for a two-team approach, and minimal donor site morbidity. However, complications related to microvascular surgery may be overcome by increased surgical experience and by intensive flap monitoring in early postoperative period.

Home Health Care Service Using Routine Vital Sign Checkup and Electronic Health Questionnaires (주기적인 생리변수 측정과 전자건강설문을 이용한 재택건강관리서비스)

  • 박승훈;우응제;이광호;김종철
    • Journal of Biomedical Engineering Research
    • /
    • v.22 no.5
    • /
    • pp.469-477
    • /
    • 2001
  • In this Paper. we describe a home health care service using electronic health questionnaires and routine checkup of vital signs Including ECG (Electrocardiography) , blood pressure. and SpO$_2$ (Oxygen Saturation) . This system is for patients at home with chronic diseases, discharged Patients, or any normal people for the Prevention of disease The service requires a home health care terminal and a PC with Interned connection installed at Patient home. The distance health care management center is equipped with a vital-sign and questionnaire interpreter as well as database, Web, and notification servers with UMS (Unified Messaging System). Participating Physician can access the servers at the center using a Web browser running on a PC available to them at any time. These components are linked together through various kinds of data and voice communication channels including PSTN (Public Switched Telephone Network) . CATV(Community Antenna TV) . Interned. and mobile communication network. Following the Physician's direction given to a Patient. he or she uses the home health care terminal to collect vital signs and fill out the questionnaire. When the terminal automatically transmits these data to the management center. the data interpreter and servers at the center process the information fo1lowing the Protocol implemented on the system. Physicians can retrieve and review data corresponding to their Patients and send back their diagnostic reports to the center. UMS at the center delivers the physician 's recommendation to the corresponding patient through the notification server. Patients can also reprieve and review their own records as well as diagnostic reports from physicians. The system Provides a new way of collecting diagnostic information and delivering doctor's recommendation to patients at home for their health management. Future works are needed in the development of new technology for measurements and interpretations of various vital signs .

  • PDF

Simulation of Low-Grazing-Angle Coherent Sea Clutter (Low Grazing Angle에서의 코히어런트 해상 클러터 시뮬레이션)

  • Choi, Sang-Hyun;Song, Ji-Min;Jeon, Hyeon-Mu;Chung, Yong-Seek;Kim, Jong-Mann;Hong, Seong-Won;Yang, Hoon-Gee
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.29 no.8
    • /
    • pp.615-623
    • /
    • 2018
  • The probability density function(PDF) for the amplitude of the reflectivity of low-grazing-angle sea clutter has generally been modeled by a compound-Gaussian distribution, rather than by the Rayleigh distribution, owing to the intensity variation of each clutter patch over time. The texture component forming the reflectivity has been simulated by combining Gamma distribution and memory-less nonlinear transformation(MNLT). On the other hand, there is no typical method available that can be used to simulate the speckle component. We first review Watt's method, wherein the speckle is simulated starting from the Doppler spectrum of the received echoes that is modeled as having a Gaussian shape. Then, we introduce a newly proposed method. The proposed method simulates the speckle by manipulating a clutter covariance matrix through the Cholesky decomposition after minimizing the effect of adjacent clutter patches using an equalizer. The feasibility of the proposed method is validated through simulation, wherein the results from two methods are compared in terms of the Doppler spectrum and the correlation function.

Multi-step Ahead Link Travel Time Prediction using Data Fusion (데이터융합기술을 활용한 다주기 통행시간예측에 관한 연구)

  • Lee, Young-Ihn;Kim, Sung-Hyun;Yoon, Ji-Hyeon
    • Journal of Korean Society of Transportation
    • /
    • v.23 no.4 s.82
    • /
    • pp.71-79
    • /
    • 2005
  • Existing arterial link travel time estimation methods relying on either aggregate point-based or individual section-based traffic data have their inherent limitations. This paper demonstrates the utility of data fusion for improving arterial link travel time estimation. If the data describe traffic conditions, an operator wants to know whether the situations are going better or worse. In addition, some traffic information providing strategies require predictions of what would be the values of traffic variables during the next time period. In such situations, it is necessary to use a prediction algorithm in order to extract the average trends in traffic data or make short-term predictions of the control variables. In this research. a multi-step ahead prediction algorithm using Data fusion was developed to predict a link travel time. The algorithm performance were tested in terms of performance measures such as MAE (Mean Absolute Error), MARE(mean absolute relative error), RMSE (Root Mean Square Error), EC(equality coefficient). The performance of the proposed algorithm was superior to the current one-step ahead prediction algorithm.

Comparison Study of Image Quality of Direct and Indirect Conversion Digital Mammography System (직접 및 간접변환 방식의 디지털 유방 X선 촬영시스템의 영상화질 비교 연구)

  • Park, Hye-Suk;Oh, Yu-Na;Jo, Hee-Jeong;Kim, Sang-Tae;Choi, Yu-Na;Kim, Hee-Joung
    • Progress in Medical Physics
    • /
    • v.21 no.3
    • /
    • pp.239-245
    • /
    • 2010
  • The purpose of this study is to comprehensively compare and evaluate the characteristics of image quality for digital mammography systems which use a direct and indirect conversion detector. Three key metrics of image quality were evaluated for the direct and indirect conversion detector, the modulation transfer function (MTF), normalized noise power spectrum (NNPS), and detective quantum efficiency (DQE), which describe the resolution, noise, and signal to noise performance, respectively. DQE was calculated by using a edge phantom for MTF determination according to IEC 62220-1-2 regulation. The contrast to noise ratio (CNR) was evaluated according to guidelines offered by the Korean Institute for Accreditation of Medical Image (KIAMI). As a result, the higher MTF and DQE was measured with direct conversion detector compared to indirect conversion detector all over spatial frequency. When the average glandular dose (AGD) was the same, direct conversion detector showed higher CNR value. The direct conversion detector which has higher DQE value all over spatial frequency would provide the potential benefits for both improved image quality and lower patient dose in digital mammography system.

Optimizing Imaging Conditions in Digital Tomosynthesis for Image-Guided Radiation Therapy (영상유도 방사선 치료를 위한 디지털 단층영상합성법의 촬영조건 최적화에 관한 연구)

  • Youn, Han-Bean;Kim, Jin-Sung;Cho, Min-Kook;Jang, Sun-Young;Song, William Y.;Kim, Ho-Kyung
    • Progress in Medical Physics
    • /
    • v.21 no.3
    • /
    • pp.281-290
    • /
    • 2010
  • Cone-beam digital tomosynthesis (CBDT) has greatly been paid attention in the image-guided radiation therapy because of its attractive advantages such as low patient dose and less motion artifact. Image quality of tomograms is, however, dependent on the imaging conditions such as the scan angle (${\beta}_{scan}$) and the number of projection views. In this paper, we describe the principle of CBDT based on filtered-backprojection technique and investigate the optimization of imaging conditions. As a system performance, we have defined the figure-of-merit with a combination of signal difference-to-noise ratio, artifact spread function and floating-point operations which determine the computational load of image reconstruction procedures. From the measurements of disc phantom, which mimics an impulse signal and thus their analyses, it is concluded that the image quality of tomograms obtained from CBDT is improved as the scan angle is wider than 60 degrees with a larger step scan angle (${\Delta}{\beta}$). As a rule of thumb, the system performance is dependent on $\sqrt{{\Delta}{\beta}}{\times}{\beta}^{2.5}_{scan}$. If the exact weighting factors could be assigned to each image-quality metric, we would find the better quantitative imaging conditions.

State-of-the-art Studies on Infrasound Monitoring in Korea (국내 인프라사운드 관측기술의 최신 연구 동향)

  • Che, Il-Young;Lee, Hee-Il;Jeon, Jeong-Soo;Shin, In-Cheul;Chi, Heon-Cheol
    • Geophysics and Geophysical Exploration
    • /
    • v.13 no.3
    • /
    • pp.286-294
    • /
    • 2010
  • Korea Institute of Geoscience and Mineral Resources (KIGAM) has installed and operated seven seismoacoustic (infrasound) arrays as well as seismic stations in Korea. The seismo-acoustic array, which consists of co-located seismometers and micro-barometers, can observe both seismic and infrasonic signals from distant explosive phenomena. The infrasound is defined as low frequency (<20 Hz) acoustic waves in atmosphere. In particular, it can be detectable at long distance due to its low energy attenuation during propagation in atmosphere. KIGAM adopted the infrasound technology to discriminate surface explosions from earthquakes only because the surface explosion generally generates infrasound following seismic signal. In addition to surface explosions, these arrays have detected diverse geophysically natural and artificial phenomena, such as infrasound signal from the North Korean nuclear test. This review introduced the state-of-the-art studies and examples of infrasonic signals in and around the Korean Peninsula. In conclusion, infrasound technology would be clearly accepted itself as a new Earth monitoring technology by expanding its detectable regime to lithosphere-Earth surface-atmosphere. In future, an advanced technology, which allows to analyze seismic and infrasonic wave fields together, will enlarge the understanding of geophysical phenomena and be used as a robust analysis method for remote explosive phenomena in the broad infrasound regime.