• 제목/요약/키워드: baseline suppression

검색결과 26건 처리시간 0.024초

Efficient baseline suppression via TIP and modified DEPTH

  • Hyun, Namgoong
    • 한국자기공명학회논문지
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    • 제26권4호
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    • pp.51-58
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    • 2022
  • The baseline flattened NMR spectrum has been achieved by several methodologies including pulse manipulation with a series of phase cycling. The background signal inherent in the probe is also main source of baseline distortion both in solution and solid NMR. The simple direct polarization with 90° pulse flipping the magnetization from the z-axis onto the receiver coil requires the strong rf pulse enough to encompass the wide frequency range to excite the resonance of interest nuclei. Albeit the perfect polarization 90° pulse, the signal from the unwanted magnetic fields such as background signal can not be completely suppressed by suitable phase cycling. Moreover, slowly baseline wiggling signal from the low 𝛾 nuclei is not easy to eliminate with multiple pulse manipulation. So there is still need to contrive the new scheme for that purpose in an adroit manner. In this article new triple pulse excitation schemes for TIP and modified DEPTH pulse sequence are analytically examined in terms of arbitrary phase and flip angle of pulse. The suitable phase cycling for these pulse trains is necessary for the good sensitivity and resolution of the spectrum. It is observed that the 13C sensitivity TIP experiment is almost equal to the CP/MAS with modified DEPTH sequence, both of which are applicable to both solid and solution state NMR.

다중레이트 디지털 필터 설계 및 심전도 신호의 기저선 변동 및 전원 잡음 제거 (Baseline Drift Reduction and Suppression of Power Line Noises in ECG Signal by Designing Multirate Digital Filter)

  • 김정환;김현태;박상은;이정환;김경섭
    • 전기학회논문지
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    • 제63권4호
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    • pp.551-558
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    • 2014
  • Baseline drift reduction and removal of power line noises in electrocardiogram are often necessary to avoid the distortions in extracting the fiducial features. With this aim, the multirate digital filtering algorithm is suggested to design and implement Finite Impulse Response or Infinite Impulse Response Filter by changing the sampling rate with omitting or interpolating intermediate ECG data. After the experimental simulations performed, we can conclude the fact that we can suppress the baseline wander and power line disturbances in ECG signal with reducing the computational complexities in which we do not keep the original and high sampling frequency.

생각회피훈련을 이용한 생각억제와 생각대체 전략의 효과비교 (Comparison of Effects of Thought Suppression and Thought Substitution Strategies Using Thought Avoidance Training)

  • 신영은;민윤기;이영창
    • 감성과학
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    • 제24권1호
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    • pp.3-10
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    • 2021
  • 본 연구는 생각/생각회피 과제를 이용하여 의도적 생각회피, 즉 생각억제와 생각대체의 효과를 종합적으로 검증하였다. 이를 위해 연관성이 높지 않은 2음절 단어자극을 선정하고, 단일집단을 대상으로 회상조건(단서회상, 표적회상)과 훈련조건(생각, 생각억제, 생각대체, 기저선)의 정확회상률을 비교하였다. 그 결과, 훈련조건과 관계없이 표적회상에 비해 단서회상의 정확기억률이 높은 것으로 나타났으며, 회상조건과 관계없이 다른 조건에 비해 생각조건의 정확회상률이 높은 것으로 나타났다. 또한 회상조건과 훈련조건의 상호작용 효과의 경향성이 나타났으며, 세부적 검증 결과. 생각억제의 경우, 회상조건 간 차이가 나타나지 않은 반면에 생각대체의 경우에는 표적회상에 비해 단서회상의 정확기억률이 높은 것으로 나타났다. 이러한 결과는 생각억제와 생각대체전략이 모두 의도적으로 생각을 회피하는데 효과적이라는 것과 더불어 생각억제와 생각대체전략이 서로 다른 원리에 의해 발생할 수 있음을 시사한다.

Noise Suppression in NMR Spectrum by Using Wavelet Transform Analysis

  • Kim, Daesung;Youngdo Won;Hoshik Won
    • 한국자기공명학회논문지
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    • 제4권2호
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    • pp.103-115
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    • 2000
  • Wavelet transforms are introduced as a new tool to distinguish real peaks from the noise contaminated NMR data in this paper. New algorithms of two wavelet transforms including Daubechies wavelet transform as a discrete and orthogonal wavelet transform (DWT) and Morlet wavelet transform as a continuous and nonorthogonal wavelet transform(CWT) were developed fer noise elimination. DWT and CWT method were successfully applied to the noise reduction in spectrum. The inevitable distortion of NMR spectral baseline and the imperfection in noise elimination were observed in DWT method while CWT method gives a better baseline ahape and a well noise suppressed spectrum.

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아편양 순응제가 백서의 억제된 자발적 교대행동에 미치는 영향 (Effects of Opioid Agonists on the Suppressed Spontaneous Alternation Behaviour in Rats)

  • 이기철;전성일;장환일;이정호;최영민;김성호;류정환;최미
    • 생물정신의학
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    • 제6권2호
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    • pp.193-201
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    • 1999
  • This study was designed to evaluate the effects of opioid receptor agonists on the spontaneous alternation behaviour in an animal model of obsessivecompulsive disorder in rats. According to the theory that dopamine is related to the biological etiology of obsessive-compulsive disorder, the effect of the nalbuphine(opioid kappa agonist) and the tramadol(opioid mu agonist), which act as manipulating agents on the inhibition or stimulation of dopamine release, in the spontaneous alternation behaviour were evaluated. 24 hours prior to the experiment, rats were food-deprived. These rats were put into the T-maze, in which white and black goal boxes were baited with small amounts of chocolate milk. Each rat was given 2 set of 7 trials during which it was placed in the start box and allowed to choose the one of the goal boxes for each time. After identifying the stable baseline of spontaneous alternation behaviour, nonselective 5-HT agonist 5-MeODMT(1.25mg/kg/IP) disrupted spontaneous alternation. Rats were stratified into fluoxetine(10mg/kg/IP), nalbuphine(10mg/kg/IP), tramadol(46.4mg/kg/IP), and saline(0.5cc/IP) injection group with experimental drug treatment for 21 days. The effects on the 5-MeODMT(1.25mg/kg/IP) induced disruption of spontaneous alternation behaviour were checked at the next day of discontinuation of drug treatment. The results were as follows ; 1) At the day after 21 days of the drug treatment, the nalbuphine treated group and the fluoxetine treated group showed significant difference from the tramadol treated group and the saline treated group in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. 2) Within each drug treatment group, the fluoxetine treated group showed significant difference between before and after the treatment of fluoxetine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. And also, the nalbuphine treated group showed significant difference between before and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. There was no difference between the baseline and after the treatment of nalbuphine in the 5-MeODMT(1.25mg/kg/IP) induced suppression of spontaneous alternation behaviour. We indentified that the opioid kappa agonist that act as dopamine release inhibitor affect the spontaneous alternation behaviour which is an animal model of obsessive-compulsive disorder in rat.

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만성 난치성 기침에 대한 기침 억제 요법의 효과 (The Benefit of Supplemental Cough Suppression Therapy for Chronic Refractory Cough)

  • 유용준;박혜진;한명월;김지원
    • 대한후두음성언어의학회지
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    • 제33권1호
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    • pp.26-30
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    • 2022
  • Background and Objectives Cough suppression therapy (CST) is a physiotherapy that can be used for patients with chronic refractory cough (CRC). We aimed to investigate the efficacy of CST for CRC. Materials and Method A prospective randomized controlled trial was conducted in 27 patients with CRC. Participants were randomized to receive either standard mucolytic medications for CRC combined with supplemental CST (CST group) or standard medications alone (control group). CST consists of laryngeal hygiene management, humidification, cough suppression technique, breathing method, and counseling. We assessed the symptoms change at baseline and week 4 with the Leicester Cough Questionnaire (LCQ). Secondary efficacy outcomes included the degree of cough Visual Analog Scale (VAS) score (0 to 100 scale). Results From 2019 to 2021, 14 CST group patients and 13 control group patients were included. The improvement was significantly greater in the CST group than in the control group for cough VAS score (36.67 to 13.33 vs. 74.29 to 16.43, p<0.001). Patients in the CST group had a significant improvement in total (70.14 to 107.71, p=0.005), physical (31.42 to 43.86, p=0.015), psychological (23.57 to 40.14, p=0.003), and social (15.14 to 23.71, p=0.005) LCQ scores. However, there was not a significant pre- to post-treatment LCQ score improvement in control group. Conclusion CST might be an effective supplemental intervention for CRC.

T2 Mapping with and without Fat-Suppression to Predict Treatment Response to Intravenous Glucocorticoid Therapy for Thyroid-Associated Ophthalmopathy

  • Linhan Zhai;Qiuxia Wang;Ping Liu;Ban Luo;Gang Yuan;Jing Zhang
    • Korean Journal of Radiology
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    • 제23권6호
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    • pp.664-673
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    • 2022
  • Objective: To evaluate the performance of baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping of the extraocular muscles (EOMs) in the prediction of treatment response to intravenous glucocorticoid (IVGC) therapy for active and moderate-to-severe thyroid-associated ophthalmopathy (TAO) and to investigate the effect of fat-suppression (FS) in T2 mapping in this prediction. Materials and Methods: A total of 79 patients clinically diagnosed with active, moderate-to-severe TAO (47 female, 32 male; mean age ± standard deviation, 46.1 ± 10 years), including 43 patients with a total of 86 orbits in the responsive group and 36 patients with a total of 72 orbits in the unresponsive group, were enrolled. Baseline clinical characteristics and pretherapeutic histogram parameters derived from T2 mapping with FS (i.e., FS T2 mapping) or without FS (i.e., conventional T2 mapping) of EOMs were compared between the two groups. Independent predictors of treatment response to IVGC were identified using multivariable analysis. Receiver operating characteristic (ROC) curve analysis was performed to evaluate the predictive performance of the prediction models. Differences between the models were examined using the DeLong test. Results: Compared to the unresponsive group, the responsive group had a shorter disease duration, lower kurtosis (FS-kurtosis), lower standard deviation, larger 75th, 90th, and 95th (FS-95th) T2 relaxation times in FS mapping and lower kurtosis in conventional T2 mapping. Multivariable analysis revealed that disease duration, FS-95th percentile, and FS-kurtosis were independent predictors of treatment response. The combined model, integrating all identified predictors, had an optimized area under the ROC curve of 0.797, 88.4% sensitivity, and 62.5% specificity, which were significantly superior to those of the imaging model (p = 0.013). Conclusion: An integrated combination of disease duration, FS-95th percentile, and FS-kurtosis was a potential predictor of treatment response to IVGC in patients with active and moderate-to-severe TAO. FS T2 mapping was superior to conventional T2 mapping in terms of prediction.

스마트폰 연동 생체신호 왜곡보정을 위한 디지털 필터 설계 및 구현 (Suppression of Noisy Characteristics of Biosignals by Implementing Digital Filters with an Android Smartphone Platform)

  • 김정환;김경섭;신승원;김현태;이정환;김동준
    • 전기학회논문지
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    • 제61권10호
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    • pp.1518-1523
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    • 2012
  • In this study, the novel digital filtering algorithms are implemented to suppress the noisy characteristics embedded in ambulatory electrocardiogram signals by an android smartphone platform. With this aim, Graphical User Interface (GUI) is designed and implemented by utilizing multithread-Java programming to realize Finite Impulse Response and Infinite Impulse Response filter. With simulating our implemented digital filters built in an android smartphone, we can find the fact that we can efficiently suppresses the noisy characteristics due to baseline wandering and 60 Hz powerline source fluctuations especially in electrocardiograms.

Optimization of 1D 1H Quantitative NMR (Nuclear Magnetic Resonance) Conditions for Polar Metabolites in Meat

  • Kim, Hyun Cheol;Ko, Yoon-Joo;Kim, Minsu;Choe, Juhui;Yong, Hae In;Jo, Cheorun
    • 한국축산식품학회지
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    • 제39권1호
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    • pp.1-12
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    • 2019
  • The objective of this study was to establish an optimized 1D $^1H$ quantitative nuclear magnetic resonance (qNMR) analytical method for analyzing polar metabolites in meat. Three extraction solutions [0.6 M perchloric acid, 10 mM phosphate buffer, water/methanol (1:1)], three reconstitution buffers [20 mM 3-morpholinopropane-1-sulfonic acid, 2-[4-(2-hydroxyethyl)piperazin-1-yl]ethanesulfonic acid, phosphate buffer], and two pulse programs (zg30, noesypr1d) were evaluated. Extraction with 0.6 M perchloric acid and 20 mM phosphate resulted in a stable baseline and no additional overlap for quantifying polar metabolites in chicken breast. In qNMR analysis, zg30 pulse program (without water-suppression) showed smaller relative standard deviation (RSD) and faster running time than noesypr1d (water-suppression). High-performance liquid chromatography was compared with qNMR analyses to validate accuracy. The zg30 pulse program showed good accuracy and lower RSD. The optimized qNMR method was able to apply for beef and pork samples. Thus, an optimized 1D $^1H$ qNMR method for meat metabolomics was established.

18개월간 자일리톨 껌 저작에 따른 Streptococcus mutans의 집락 형성 억제효과 (Inhibitory effects on colonization of Streptococcus mutans by eighteen months xylitol consumption)

  • 박지혜;안상헌;구효진;최연희;송근배
    • 한국산학기술학회논문지
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    • 제11권1호
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    • pp.375-382
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    • 2010
  • 본 연구는 임신 및 수유기간 동안 구강위생상태가 불량해질 수 있는 임산부에 있어서 장기간의 자일리톨 섭취가 Streptococcus mutans(S. mutans) 집락수에 어떠한 영향을 미치는 지에 대해 알아보고자 하였다. 임산부구강건강 예방프로그램에 대상자를 자발적으로 모집하여 두 군(실험군과 대조군)으로 나눈 후 18개월간 추적 조사하였다. 자극성 타액은 오후시간(1:00-3:00 p.m.)에 초기, 6개월, 12개월 및 18개월에 채취하였다. 구강보건행태(잇솔질 횟수와 정기구강검진)에 관한 정보는 설문지를 통해서 얻어졌다. 타액 내 자일리톨군의 연구기간에 따른 S. mutans 평균집락수의 차이는 통계적으로 유의하였으며, 특히 연구초기에 비해 출산 후 6개월, 12개월 및 18개월 모두에서 유의한 감소를 나타내었다. 반면 대조군에서는 연구초기에 비해 출산 후 18개월에서만 유의한 감소를 나타내었다. 이상의 결과를 종합해 보면, 자일리톨의 장기적인 섭취는 구강 내 S. mutans 집락수를 감소시킴으로써 임산부들에 있어서도 치아우식증 예방효과가 나타날 수 있을 것으로 사료된다.