• 제목/요약/키워드: frequency-dependent

검색결과 1,821건 처리시간 0.031초

Individual Variation of Radiation Adaptive Responses in Patients Undergoing Imaging Studies Using $^{99m}Tc$ Labeled Radiopharmaceuticals ($^{99m}Tc$ 표지 방사성의약품을 이용한 핵의학 영상검사를 받은 환자에서 방사선 적응반응의 개인간 차이에 대한 연구)

  • Li, Ming-Hao;Bom, Hee-Seung;Kwon, An-Sung;Kim, Young-Ho;Kim, Ji-Yeul
    • Journal of Radiation Protection and Research
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    • 제28권2호
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    • pp.117-125
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    • 2003
  • It was reported that radiopharamaceuticals induced radiation adaptive response (RAR) in patients undergoing nuclear medicine imaging studies. Individual variations of RAR were not studied well. The purpose of this study was to evaluate individual variation of RAR in patients undergoing nuclear medicine imaging studies. Peripheral lymphocytes were collected from 23 patients undergoing $^{99m}Tc-diethylenetriamine$ pentaacetic acid $(^{99m}Tc-DTPA)$ renal scintigraphy, 18 patients undergoing $^{99m}Tc-methylene$ diphosphonate $(^{99m}Tc-MDP)$ bone scintigraphy and 21 patients undergoing $^{99m}Tc-tetrofosmin\;(^{99m}Tc-TF)$ scintigraphy were collected before and 4 hours after injection of radiopharmaceuticals. The lymphocytes were exposed to challenge dose of 2 Gy gamma rays using a cell irradiator. Numbers of ring-form (R) and dicentric (D) chromosomes were counted under the light microscope. and used to calculate the frequency of chromosomal aberration [Ydr=(D+R)/total number of counted lymphocytes]. Adaptation index (k) was defined 3s ratio of Ydr in conditioned lymphocytes over Ydr in unconditioned lymphocytes. Coefficients of variance of k in $^{99m}Tc-DTPA,\;^{99m}Tc-MDP\;and\;^{99m}Tc-TF$ were 35%, 34% and 21%, respectively k was not dependent upon age, sex, and underlying diseases. There was a wide variation of RAR induced by radiopharmaceuticals among patients undergoing nuclear medicine procedures. It remains to be determined for causes of such variation.

Nonlinear Characteristic Analysis of Charging Current for Linear Type Magnetic Flux Pump Using RBFNN (RBF 뉴럴네트워크를 이용한 리니어형 초전도 전원장치의 비선형적 충전전류특성 해석)

  • Chung, Yoon-Do;Park, Ho-Sung;Kim, Hyun-Ki;Oh, Sung-Kwun
    • Journal of the Korean Institute of Intelligent Systems
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    • 제20권1호
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    • pp.140-145
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    • 2010
  • In this work, to theoretically analyze the nonlinear charging characteristic, a Radial Basis Function Neural Network (RBFNN) is adopted. Based on the RBFNN, an charging characteristic tendency of a Linear Type Magnetic Flux Pump (LTMFP) is analyzed. In the paper, we developed the LTMFP that generates stable and controllable charging current and also experimentally investigated its charging characteristic in the cryogenic system. From these experimental results, the charging current of the LTMFP was also found to be frequency dependent with nonlinear quality due to the nonlinear magnetic behaviour of superconducting Nb foil. On the whole, in the case of essentially cryogenic experiment, since cooling costs loomed large in the cryogenic environment, it is difficult to carry out various experiments. Consequentially, in this paper, we estimated the nonlinear characteristic of charging current as well as realized the intelligent model via the design of RBFNN based on the experimental data. In this paper, we view RBF neural networks as predominantly data driven constructs whose processing is based upon an effective usage of experimental data through a prudent process of Fuzzy C-Means clustering method. Also, the receptive fields of the proposed RBF neural network are formed by the FCM clustering.

A study of Korean Physical Therapist's Attitudes and Beliefs on Korean Government's National Long Term Care Insurance Program (노인 장기요양 보험 제도에 대한 부산광역시 물리치료사들의 인식도 조사)

  • Kim, Bu-Young;Park, Bo-Ram;Song, In-Kyoung;Oh, Tae-Young
    • Journal of Korean Physical Therapy Science
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    • 제18권1호
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    • pp.21-32
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    • 2011
  • Objective: This study was conducted to describe physical therapists' attitudes and beliefs towards Korean Government's National Long Term Care Insurance Program implemented last July 2008. Design: A survey research. Methodology: Participants were 143 physical therapists working in General Hospitals or University Hospitals in Busan, Korea. Each of the participants completed a questionnaire which was comprised of 22 questions. Among the 22 questions, 7 of these were independent variables such as gender, age, career, etc. while 15 of these questions were dependent variables such as the subject's expectations and reactions on the said program, opinions of the participants on the impact of the program to old people's families and relatives, participant's sentiments on social effects of this program to the society, etc. Data collection was conducted from the $20^{th}$ of July to the $5^{th}$ of August, 2008. Data were analyzed by Chi-square test, frequency and cross tabs using SPSS/PC program. Results: Based on the survey conducted, it showed that 50.3% were female respondents, 53.8% were on their twenties, 31.5% of the total respondents were married and that a percentage of 82.4% had working experiences below 10 years. About 80.4% of respondents were satisfied of their jobs and 32.4%of the respondents graduated from three - year college degree, 49.3% of the respondents graduated from four-year college degree. 95.1% of the total respondents knew the existence of the national long term care insurance program of the government and almost 78% got the information of the said program via internet, news paper or T.V. About 86% of the respondents believe that there will be future improvements in the quality of life in Korea through the said program and 82% said that there will be an increase sense of responsibility among family members to take care of their old relatives. 67.2 % of respondents believe that problems regarding old people will be solved through the government's national long term care insurance program. In aspect of Physical Therapy, 50% of the respondents expected generation of more jobs especially to physical therapists and 95% of the respondents want to work in any position in the said program especially those are more experienced ones. Conclusion: Physical Therapists in Korea are aware of the existence of the National Long Term Care Insurance Program of the Korean Government. Based on the gathered results from the survey, many experienced physical therapists of the country wanted to acquire positions in the said program especially that their expertise are needed in the said field. Through this study, it is evident that many physical therapists of the country have positive vibes on the said program and are optimistic on the outcomes of the said insurance program.

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Characteristic Intracelluar Response to Lidocaine And MK-801 of Hippocampal Neurons: An In Vivo Intracellular Neuron Recording Study

  • Choi, Byung-Ju;Cho, Jin-Hwa
    • The Korean Journal of Physiology and Pharmacology
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    • 제2권3호
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    • pp.297-305
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    • 1998
  • This study used in vivo intracellular recording in rat hippocampus to evaluate the effect of lidocaine and MK-801 on the membrane properties and the synaptic responses of individual neurons to electrical stimulation of the commissural pathway. Cells in control group typically fired in a tonic discharge mode with an average firing frequency of $2.4{\pm}0.9$ Hz. Neuron in MK-801 treated group (0.2 mg/kg, i.p.) had an average input resistance of $3.28{\pm}5.7\;M{\Omega}$ and a membrane time constant of $7.4{\pm}1.8$ ms. These neurons exhibited $2.4{\pm}0.2$ ms spike durations, which were similar to the average spike duration recorded in the neurons of the control group. Slightly less than half of these neurons were firing spontaneously with an average discharge rate of $2.4{\pm}1.1$ Hz. The average peak amplitude of the AHP following the spikes in these groups was $7.4{\pm}0.6$ mV with respect to the resting membrane potential. Cells in MK-801 and lidocaine treated group (5 mg/kg, i.c.v.) had an average input resistance of $3.45{\pm}6.0\;M{\Omega}$ and an average time constant of $8.0{\pm}1.4$ ms. The cells were firing spontaneously at an average discharge rate of $0.6{\pm}0.4$ Hz. Upon depolarization of the membrane by 0.8 nA for 400 ms, all of the tested cells exhibited accommodation of spike discharge. The most common synaptic response contained an EPSP followed by early-IPSP and late-IPSP. Analysis of the voltage dependence revealed that the early-IPSP and late-IPSP were putative $Cl^--and\;K^+-dependent$, respectively. Systemic injection of the NMDA receptor blocker, MK-801, did not block synaptic responses to the stimulation of the commissural pathway. No significant modifications of EPSP, early-IPSP, or late-IPSP components were detected in the MK-801 and/or lidocaine treated group. These results suggest that MK-801 and lidocaine manifest their CNS effects through firing pattern of hippocampal pyramidal cells and neural network pattern by changing the synaptic efficacy and cellular membrane properties.

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A Study on the Actual Condition of Gas Equipment and Gas Safety Consciousness Survey to Improve Gas Safety of Gas Consumers (가스 소비자들의 가스안전성 제고를 위한 가스기기 사용 실태 및 가스안전의식 조사에 관한 연구)

  • Ko, Jaesun
    • Journal of the Society of Disaster Information
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    • 제13권4호
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    • pp.465-475
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    • 2017
  • As a result of a survey on households using gas, gas safety accidents have been declining linearly in 2006. However, when analyzing the causes of gas accidents, accidents detail caused by carelessness have increased to 62%It is analyzed that urgent measures are needed. In addition, 7 households per 10 households perceive city gas as safe, but 30% of them recognize that gas safety accidents are likely to occur in their homes in the future. Even though city gas use is relatively safe,It is recognized that there is a risk. Although the perception of the gas safety of the city gas consumers is not related to the age and gender income level, it is analyzed that it is highly educated and experienced direct or indirect gas safety accident, the perception of safety was relatively low. In order to reduce gas safety accidents, the installation of gas safety equipment for elderly households should be continuously supplied. As a result of investigating the disposal costs in case of various disasters, 66% of the insurance costs were found to be highly dependent on insurance. In addition, to reduce gas safety accidents, the installation of gas safety devices for elderly households should be continuously implemented.

Non-invasive Measurements of the Thickness of YBCO Thin Films by Using Microwave Resonators: Roles of the Uncertainty in the Calibration Film Thickness (마이크로파 공진기를 이용한 YBCO 박막 두께의 비파괴적 측정: 캘리브레이션 박막 두께의 불확도의 역할)

  • Kim, Myung-Su;Jung, Ho-Sang;Yang, Woo-Il;Lee, Sang-Young
    • Progress in Superconductivity
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    • 제14권1호
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    • pp.45-51
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    • 2012
  • Microwave metrology for the thickness of metallic or superconductive films provides a new way to measure the film thickness in a non-invasive way by using microwave resonators, with the measurement accuracy affected by standard uncertainties in the resonator quality factor, temperature-dependent resonant frequency and the dimensions of the resonators. Here we study effects of the standard uncertainty in the thickness, $t_{cal}$, of a calibration $YBa_2Cu_3O_{7-{\delta}}$ (YBCO) film on the measured thicknesses, $t_{RF}$, by using a ~ 40 GHz microwave resonator. For the study, we used five YBCO films having the thicknesses of 70 - 360 nm, for which relative standard uncertainties in $t_{RF}$ due to that in $t_{cal}$ are obtained. The standard uncertainty in $t_{cal}$ was determined with the surface roughness of the film taken into account. It appeared that relative standard uncertainty in $t_{cal}$ significantly affects the $t_{RF}$ values, with the values of 1% (5%) in the former resulting in those of 1-2% (5-9%) for the latter at 10 K. Our results show that, for realizing relative standard uncertainties less than 5% in $t_{RF}$ for all the YBCO films, the surface roughness of the calibration films should be small enough to realize a relative standard uncertainty of less than 2.7% in $t_{cal}$.

Thermal Degradation of Thermoplastic Polyurethane Modified with Polycarbonate (열가소성 폴리우레탄으로 개질된 폴리카보네이트에서 TPU의 열분해)

  • 권회진;차윤종;최순자
    • Polymer(Korea)
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    • 제24권3호
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    • pp.314-325
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    • 2000
  • Thermal degradation of thermoplasitc polyurethane modified polycarbonate has been investigated by means of DSC, GPC and FT-IR techniques. The polyurethanes used in this study are TPU-35 and TPU-53 containing 35.5 and 53.4 wt% of hard segments, respectively. The more content of hard segment, the higher the glass transition temperature (T$_{g}$) of TPU was observed. On the other hand, the T$_{g}$ of the TPU modified PC decreased with the content of TPU and the annealing temperature regardless of the hard segment contents. The latter behavior nay arise from the thermal degradation of TPU upon annealing process: the observed thermal degradation temperatures were at 240 and 25$0^{\circ}C$ for the PC/TPU-35 and PC/TPU-53, respectively. The molecular weight, molecular weight distribution and viscosity agree well with the DSC measurement, which implicates a thermal degradation of TPU. In addition, thermal stability of the TPU modified PC linearly decreased with an incorporation of TPU. Transesterification or any interaction was not observed using FT-IR: the evidence was no frequency shift or any variance betwere the carbonyl stretching and NH group. For the specimens prepared below the degradation temperature, the enhancement of the thickness dependent impact strength of the PC/TPU blend was observed, and the morphology of the two blends was compared.d.

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Dependences of Ultrasonic Parameters for Osteoporosis Diagnosis on Bone Mineral Density (골다공증 진단을 위한 초음파 변수의 골밀도에 대한 의존성)

  • Hwang, Kyo Seung;Kim, Yoon Mi;Park, Jong Chan;Choi, Min Joo;Lee, Kang Il
    • Journal of the Korean Society for Nondestructive Testing
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    • 제32권5호
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    • pp.502-508
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    • 2012
  • Quantitative ultrasound technologies for osteoporosis diagnosis measure ultrasonic parameters such as speed of sound(SOS) and normalized broadband ultrasound attenuation(nBUA) in the calcaneus (heel bone). In the present study, the dependences of SOS and nBUA on bone mineral density in the proximal femur with high risk of fracture were investigated by using 20 trabecular bone samples extracted from bovine femurs. SOS and nBUA in the femoral trabecular bone samples were measured by using a transverse transmission method with one matched pair of ultrasonic transducers with a center frequency of 1.0 MHz. SOS and nBUA measured in the 20 trabecular bone samples exhibited high Pearson's correlation coefficients (r) of r = 0.83 and 0.72 with apparent bone density, respectively. The multiple regression analysis with SOS and nBUA as independent variables and apparent bone density as a dependent variable showed that the correlation coefficient r = 0.85 of the multiple linear regression model was higher than those of the simple linear regression model with either parameter SOS or nBUA as an independent variable. These high linear correlations between the ultrasonic parameters and the bone density suggest that the ultrasonic parameters measured in the femur can be useful for predicting the femoral bone mineral density.

Effect of the hatchery larval sieving on the larval growth, scuticociliate occurrence, and ensuing spat growth of Patinopecten yessoensis (참가리비, Patinopecten yessoensis 인공종묘 생산시 환수가 유생에 미치는 영향-유생성장, 스쿠티카충 발생, 치패성장의 관점)

  • Jo, Q-Tae;Kim, Su-Kyoung;Lee, Chae-Sung;Lee, Jin-Ho;Park, Mi-Seon;Moon, Tae-Suk
    • Journal of fish pathology
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    • 제23권3호
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    • pp.303-311
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    • 2010
  • Our previous finding summarizing that larval sieving process is inevitable but triggers the outbreak of scutica-like ciliates (SLCs) in the seed production of Patinopecten yessoensis urged further study to determine best suggestable sieving interval in an agreeable range of water quality. In the mass seed production of the scallop, SLC outbreak was closely related to the larval sieving in which larvae were drained on the basis of every 3-day (5T), 5-day (3T), 7-day (2T), or 9-day (1T) from culture tanks onto a mesh screen and placed back into new water in cleaned tanks. The larval performance of growth and survival was clearly dependent on the sieving intervals. It was in order of 3T, 5T, 2T, and 1T for both of growth and survival and in reverse order for SLC infection frequency, confirming that larval sieving is necessary but damageable if it overwhelms the larval resistance. Interestingly, the larval damages by the sieving persisted to their ensuing spat life in terms of nursery growth, survival, and abnormality.

Factors Associated with Self-rated Health Status for the Elderlies in Urban Areas (일부 도시지역 노인들의 주관적 건강상태와 관련 요인)

  • Lee, Hu-Yeon;Baek, Jong-Tae;Cho, Young-Chae
    • Journal of the Korea Academia-Industrial cooperation Society
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    • 제17권10호
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    • pp.569-581
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    • 2016
  • The purpose of this study was to determine factors affecting self-rated health status among the elderly in urban areas. The study subjects were 390 persons aged 65 years and older who had lived more than 5 years in D city. Interviews from the questionnaire were conducted from June through August 2016. The distribution of self-rated health status was rated in terms of dependent variables, with odds ratios and their 95% confidence intervals calculated using unconditional logistic models. As a result, 67.2% of the study subjects answered that they were healthy, whereas 32.8% were unhealthy. In the logistic regression analysis, disability and lowered IADL greatly lowered self-rated health status. The group without an occupation, living expenses from governmental subsidies, frequency of relative contents is seldom, anxiety is high, subjective sleep quality is low, satisfaction of daily life is low, had low levels of self-rated health status. Above results suggest that the self-rated health status of the elderly in urban areas is closely related to sociodemographic characteristics, physical health status, social activity participation, and psychosocial factors.