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A Rapid Signal Acquisition Scheme for Noncoherent UWB Systems (비동기식 초광대역 시스템을 위한 고속 신호 동기획득 기법)

  • Kim Jae-Woon;Yang Suck-Chel;Choi Sung-Soo;Shin Yo-An
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.4C
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    • pp.331-340
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    • 2006
  • In this Paper, we propose to extend the TSS-LS(Two-Step Search scheme with Linear search based Second step) scheme which was already proposed by the authors for coherent UWB(Ultra Wide Band) systems, to rapid and reliable acquisition of noncoherent UWB systems in multipath channels. The proposed noncoherent TSS-LS employing simple energy window banks utilizes two different thresholds and search windows to achieve fast acquisition. Furthermore, the linear search is adopted for the second step in the proposed scheme to correctly find the starting point in the range of effective delay spread of the multipath channels, and to obtain reliable BER(Bit Error Rate) performance of the noncoherent UWB systems. Simulation results with multipath channel models by IEEE 802.15.3a show that the proposed two-step search scheme can achieve significant reduction of the required mean acquisition time as compared to general search schemes. ]n addition, the proposed scheme achieves quite good BER performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

Thickness Evaluation of the Aluminum Using Pulsed Eddy Current (펄스 와전류를 이용한 알루미늄 두께 평가)

  • Lee, Jeong-Ki;Suh, Dong-Man;Lee, Seung-Seok
    • Journal of the Korean Society for Nondestructive Testing
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    • v.25 no.1
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    • pp.15-19
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    • 2005
  • Conventional eddy current testing has been used for the detection of the defect-like fatigue crack in the conductive materials, such as aluminum, which uses a sinusoidal signal with very narrow frequency bandwidth, Whereas, the pulsed eddy current method uses a pulse signal with a broad bandwidth. This can allow multi-frequency eddy current testing, and the penetration depth is greater than that of the conventional eddy current testing. In this work, a pulsed eddy current instrument was developed for evaluating the metal loss. The developed instrument was composed of the pulse generator generating the maximum square pulse voltage of 40V, an amplifier controlled up to 52dB, an A/D converter of 16 bit and the sampling frequency of 20 MHz, and an industrial personal computer operated by the Windows program. A pulsed eddy current probe was designed as a pancake type in which the sensing roil was located inside the driving roil. The output signals of the sensing roil increased rapidly wich the step pulse driving voltage かn off, and the latter part of the sensing coil output voltage decreased exponentially with time. The decrement value of the output signals increased as the thickness of the aluminum test piece increased.

Usefulness Evaluation of HRCT using Reconstruction in Chest CT (흉부CT 검사 시 HRCT 영상 재구성의 유용성)

  • Park, Sung-Min;Kim, Keung-Sik;Kang, Seong-Min;Yoo, Beong-Gyu;Lee, Ki-Bae
    • Korean Journal of Digital Imaging in Medicine
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    • v.17 no.1
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    • pp.13-18
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    • 2015
  • Purpose : Skip the repetitive HRCT axial scan in order to reduce the exposure of patients during chest HRCT scan, Helical Scan Data into a reconstructed image, and exposure of the patient change and visually evaluate the usefulness of the HRCT images. Materials and method : Patients were enrolled in the survey are 50 people who underwent chest CT scans of patients who presented to the hospital from January 2015 to March 2015. 50 people surveyed 22 people men and 28 people women people showed an average distribution of 30 to 80 years age was 48 years. 50 patients to Somatom Sensation 64 ch (Siemens) model with 120 kVp tube voltage to a reference mAs tube current to mAs (Care dose, Siemens) as a whole, including the lungs and the chest CT scan was performed. Scan upon each patient CARE dose 4D (Automatic exposure control, Siemens Medical Solution Erlangen, Germany) was to maintain the proper radiation dose scan every cross-section through a device that automatically adjusts the tube current of. CT scan is the rotation time of the Tube slice collimation, slice width 0.6 mm, pitch factor was made under the terms of 1.4. CT scan obtained after the raw data (raw data) to the upper surface of the axial images and coronal images for each slice thickness 1 mm, 5 mm intervals in the high spatial frequency calculation method (hight spatial resolution algorithm, B60 sharp) was the use of the lung window center -500 HU, windows were reconstructed into images in the interval -1000 HU to see. Result : 1. Measure the total value of DLP 50 patients who proceed to chest CT group A (Helical Scan after scan performed with HRCT) and group B (Helical Scan after the HR image reconstruction to the original data) compared with the group divided, analysis As a result of the age, but show little difference for each age group it had a decreased average dose of about 9%. 2. A Radiation read the results of the two Radiologist and a doctor upper lobe and middle lobe of the lung takes effect the visual evaluation is not a big difference between the two images both, depending on the age of the patient, especially if the blood vessels of the lower lobe (A: 3.4, B: 4.6) and bronchi(A: 3.8, B4.7) image shake caused by breathing in anxiety (blurring lead) to the original data (raw data) showed that the reconstructed image is been more useful in diagnostic terms. Conclusion : Scan was confirmed a continuous, rapid motion video to get Helical scan is much lower lobe lung reduction in visual blurring, Helical scan data to not repeat the examination by obtaining HRCT images reorganization reduced the exposure of the patient.

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Expanding Health Education Plan For Improving Public Health (국민건강증진을 위한 보건교육확대방안에 관한 연구)

  • Yun, Gi-Seon;Park, Chung-Yeol
    • The Journal of the Korea Contents Association
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    • v.15 no.3
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    • pp.303-317
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    • 2015
  • Although the public health centers have been initiating health education recently, it is not extending as expected and the participation of the program is low. The reason is that the office workers have few opportunities to receive health education since there are few public health centers in relation to the population. Much time is required for travel and attendance of the classes. In order to solve this problem, the aim is to increase participation in health education, improve the overall public health awareness, expand the number of health education locations to reduce medical expenses, vitalize the lifelong educational health programs, and improve the national health insurance. In order to research about the health education expansion plan for public health improvement, a study focused on men and women above age 20 who need health education. The research sample was selected through random sampling that targeted people who participated in the health programs or the health education. The period of this survey was from September 1st to September 30th, 2014. A total of 509 participants completed the survey data for the actual analysis to propose the health education expansion plan for the public health improvement.

Importance-Performance Analysis of Selection Attributes of University Ski Lecture Environment (대학 스키 수업 환경의 선택속성 중요도-만족도 분석)

  • Kim, Sung-Duck;Lee, Yong-Kuk
    • Journal of Digital Convergence
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    • v.14 no.6
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    • pp.489-498
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    • 2016
  • The purpose of this study was to evaluate selective attributes importance and satisfaction of University Ski Lecture Environment that students perceive using IPA method. In order to achieve this goal, a questionnaire was used to gather data, and the convenient sampling method was used to select 300 members from three pertinent university in Seoul and Chungcheong-do, Gyeongsang-do Province as participants of this study. Only data from 221 respondents however were used after screening data for reliability, and SPSS for Windows(21.0 version) statistical program was used to conduct descriptive analysis, factor analysis, reliability analysis, paired samples t-test analysis, independent samples t-test analysis and IPA matrix analysis. The following results were obtained. First, significant differences between the level of satisfaction and the level of importance were found for part of the selection attributes for each group. Second, Iquadrant was included with meals and information provided factors. IIquadrant was included with instructors and class program, information provided, accommodation factors. IIIquadrant was included in accommodation and meals, time-distance factors. IVquadrant was included in the information provided factor.

Comparison of Effects between Alteplase and Pamiteplase on MMPs Regulation (Alteplase와 pamiteplase에 의한 MMPs 조절 효과 비교)

  • Jung, Jae-Chang;Lee, Sun-Ryung
    • Journal of Life Science
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    • v.17 no.7 s.87
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    • pp.1019-1022
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    • 2007
  • Thrombolytic therapy with tissue plasminogen activator (tPA) can improve the clinical outcome of ischemic stroke patients. However, its clinical application is limited by narrow therapeutic time windows and elevated risks of cerebral hemorrhage and brain injury. In part, these effects of tPA has been related to matrix metalloproteinase-9 (MMP-9) dysregulation. Here, we investigate that the effects of alteplase (tPA with short half-life) and pamiteplase (a modified tPA with long half-life) on the MMP-9 regulation in neurovascualr unit. The total levels of MMP-2 and MMP-9 in neuronal cells are lower than astrocytes. Alteplase (1-10 μg/ml) induced upregulation of MMP-2 and MMP-9 in rat cortical neurons and astrocytes, respectively. Whereas pamiteplase in a wide range of dose did not affect the MMP-2 and MMP-9 responses in both of cells. These results suggest that pamiteplase with long half-life can be provided as a agent that overcome the side effects of alteplase.

A Comparison of the Characteristics between Intake and Non-intake Respondents of Health Foods, and Analysis of Factors Affecting the Willingness to Consume Health foods in Busan and Gyeongnam Region (부산.경남 지역 소비자의 건강식품 섭취자와 비섭취자의 특성 비교 및 섭취 의도에 영향을 미치는 요인 분석)

  • Kim, Mee-Ra;Lim, Mee-Kyoung
    • Journal of the East Asian Society of Dietary Life
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    • v.17 no.6
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    • pp.798-807
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    • 2007
  • This study compared the characteristics between intake and non-intake respondents of health foods, and analyzed the factors affecting the willingness to consume health foods, in order to provide the educational program for the desirable choice of health foods. The data were collected from 453 adults living in Busan and Gyeongnam through a self-administered questionnaire and were analyzed using SPSS Windows. Approximately 49% of the respondents consumed health foods at the time of survey. According to the results of chi-square and t tests, there were significant differences between the intake and non-intake respondents by variables, which included sex, age, educational level, marriage status, monthly household income, concerns about health, self-evaluation of health status, self-evaluation of health status compared to the same age, concerns about health foods, awareness of health foods, and internal health locus of control. In addition, the results of multinomial logistic regression analysis showed that the factors affecting willingness to consume health foods in the future were sex, educational level, marriage status, concerns about health and health foods, awareness of health foods, powerful others health locus of control, internal health locus of control, and current intake of health foods.

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Effect of Korean Medicine Combined with Electric Moxibustion in Patients with Traffic Accident-Induced Lumbago

  • Jeong, Hui-Gyeong;Kwon, Oh-Hoon;Park, Ju-Hun;Kim, Sang-Gyun;Kim, Yong-Hyeon;Lee, Ju-Young;Kim, Eun-Ji;Kim, Tae-Ju;Jeong, Sang-Jun
    • Journal of Acupuncture Research
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    • v.35 no.4
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    • pp.193-199
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    • 2018
  • Background: The purpose of this study was to investigate electric moxibustion on patients with back pain caused by road traffic accidents. Methods: This was a retrospective study (n = 112) comparing treatment with Korean medicine combined with electric moxibustion (n = 56), and Korean medicine alone (n = 56). Patient gender, age, Numeric Rating Scale (NRS), Oswestry Disability Index (ODI) and EuroQol-5 Dimension (EQ-5D) was recorded for each group at the time of hospital admission. Mean NRS measured weekly, mean ODI and EQ-5D scores were measured 2 weeks post-treatment, and evaluated by paired sample t test. using the Statistical Program for Social Science v. 25.0 for Windows. An independent, two-sample t test was used to test for a significant difference in the decrement of NRS, ODI and increment EQ-5D scores between groups. Results: NRS scores decreased in both groups after 1 week of treatment (electric moxibustion, from 5.13±0.79 to 3.86±0.67; Korean medicine alone, from 5.18±0.92 to 4.30±0.94; both p < 0.001). There was a significantly greater reduction in NRS score in the electric moxibustion group (1.27±0.59) than in the Korean medicine alone group (0.88±0.61; p = 0.001). After 2 weeks of treatment, EQ-5D scores increased significantly in the moxibustion group (0.19±0.12) compared with the Korean medicine alone group (0.13±0.20; p = 0.043). After 2 weeks of treatment, NRS and ODI scores decreased in both groups. EQ-5D increased in both groups. Conclusion: We suggest that electric moxibustion treatment may be effective for reducing early-stage back pain in patients with road traffic accident injuries.

The Development of Signal Processing Software for Single-and Multi-Voxel MR Spectroscopy (단위용적 및 다용적 기법 자기공명분광 신호처리 분석 소프트웨어의 개발)

  • Paik, Moon-Young;Lee, Hyun-Yong;Shin, Oun-Jae;Eun, Choong-Ki;Mu, Chi-Woong
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.39 no.5
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    • pp.544-555
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    • 2002
  • The aim of this study is to develop the 1H-MRS data postprocessing software for both single-voxel and multi-voxel technique, which plays and important role as a diagnostic tool in clinical field. This software is based on graphical user interface(GUI) under windows operating system of personal computer(PC). In case of single-voxel MRS, both of raw data in time-domain and spectrum data in frequency-domain are simultaneously displayed in a screen. Several functions such as DC correction, zero filling, line broadening, Lorentz-Gauss filtering and phase correction, etc. are included to increase the quality of spectrum data. In case of multi-voxel analysis, spectroscopic image reconstructed by 3-D FFT was displayed as a spectral grid and overlapped over previously obtained T1- or T2-weighted image for the spectra to be spatially registered with the image. The analysis of MRS peaks were performed by obtaining the ratio of peak area. In single-voxel method, statistically processed peak-area ratios of MRS data obtained from normal human brain are presented. Using multi-voxel method, MR spectroscopic image and metabolite image acquired from brain tumor are demonstrated.

Probabilistic Assessment of Hydrological Drought Using Hidden Markov Model in Han River Basin (은닉 마코프 모형을 이용한 한강유역 수문학적 가뭄의 확률론적 평가)

  • Park, Yei Jun;Yoo, Ji Young;Kwon, Hyun-Han;Kim, Tae-Woong
    • Journal of Korea Water Resources Association
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    • v.47 no.5
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    • pp.435-446
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    • 2014
  • Various drought indices developed from previous studies can not consider the inherent uncertainty of drought because they assess droughts using a pre-defined threshold. In this study, to consider inherent uncertainty embedded in monthly streamflow data, Hidden Markov Model (HMM) based drought index (HMDI) was proposed and then probabilistic assessment of hydrologic drought was performed using HMDI instead of using pre-defined threshold. Using monthly streamflow data (1966~2009) of Pyeongchang river and Upper Namhan river provided by Water Management Information System (WAMIS), applying the HMM after moving-averaging the data with 3, 6, 12 month windows, this study calculated the posterior probability of hidden state that becomes the HMDI. For verifying the method, this study compared the HMDI and Standardized Streamflow Index (SSI) which is one of drought indices using a pre-defined threshold. When using the SSI, only one value can be used as a criterion to determine the drought severity. However, the HMDI can classify the drought condition considering inherent uncertainty in observations and show the probability of each drought condition at a particular point in time. In addition, the comparison results based on actual drought events occurred near the basin indicated that the HMDI outperformed the SSI to represent the drought events.