• 제목/요약/키워드: relaxation frequency

검색결과 340건 처리시간 0.027초

Ionic Conductivity in Lithium-Borate-Tantalate Compound Glasses

  • Kwon, Oh Hyeok;Yang, Yong Suk;Rim, Young Hoon
    • Journal of the Korean Physical Society
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    • 제73권12호
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    • pp.1873-1878
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    • 2018
  • We have investigated the ionic conductivity and dielectric relaxation in $Li_2B_4O_7$ (LBO) and $Li_2O-B_2O_3-Ta_2O_5$ (LBTO) glasses. The sample was synthesized by using the melt quenching method. The frequency dependence of the electrical data from the LBO and LBTO glasses has been analyzed in the frameworks of the impedance Cole-Cole formalism and the universal power-law representation driven by the modified fractional Rayleigh equation. The potential barriers in the LBO and the LBTO glasses turn out to be the same. Comparing with the dc and ac activation energies of the LBO glass, these energies of the LBTO glass decrease due to the increasing Coulomb interaction of inter-cationic interaction.

Musical Genre Classification Based on Deep Residual Auto-Encoder and Support Vector Machine

  • Xue Han;Wenzhuo Chen;Changjian Zhou
    • Journal of Information Processing Systems
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    • 제20권1호
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    • pp.13-23
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    • 2024
  • Music brings pleasure and relaxation to people. Therefore, it is necessary to classify musical genres based on scenes. Identifying favorite musical genres from massive music data is a time-consuming and laborious task. Recent studies have suggested that machine learning algorithms are effective in distinguishing between various musical genres. However, meeting the actual requirements in terms of accuracy or timeliness is challenging. In this study, a hybrid machine learning model that combines a deep residual auto-encoder (DRAE) and support vector machine (SVM) for musical genre recognition was proposed. Eight manually extracted features from the Mel-frequency cepstral coefficients (MFCC) were employed in the preprocessing stage as the hybrid music data source. During the training stage, DRAE was employed to extract feature maps, which were then used as input for the SVM classifier. The experimental results indicated that this method achieved a 91.54% F1-score and 91.58% top-1 accuracy, outperforming existing approaches. This novel approach leverages deep architecture and conventional machine learning algorithms and provides a new horizon for musical genre classification tasks.

도심 수목원에서의 경관감상과 산책이 인체의 생리적 안정에 미치는 영향 (Physiological Effects of Walking and Viewing on Human at a Urban Arboretums)

  • 박범진;가재남;이민선;김선아;박민우;최윤호;정다워;권치원;염동걸;박순주;이준우;김건우
    • 한국산림과학회지
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    • 제103권4호
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    • pp.664-669
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    • 2014
  • 본 연구는 도시림에서의 경관감상과 산책이 인체의 생리적 안정에 미치는 영향을 규명하기 위해 수행되었다. 실험은 대전광역시에 위치한 한밭수목원에서 실시하였으며, 대조실험은 대전시청 앞에서 실시하였다. 20대 남자 대학생 24명(평균나이 $21.1{\pm}2.5$세)이 피험자로 참여하였고, 피험자를 세 그룹으로 나누어 수목원 내 소나무 숲, 수목원 내 연못, 도시 세 장소에 무작위 배치하였으며, 자리에 앉아 10분간 경관을 감상한 후 15분 동안 산책을 실시하였다. 측정지표로써 HRV, 혈압, 맥박수를 이용하여 생리적 변화를 측정하였다. 그 결과 도심 수목원 내에서 경관감상과 산책을 했을 때 도심과 비교하여 통계적으로 유의한 HF 성분의 증가와 수축기 혈압의 감소를 확인할 수 있었다. 본 연구를 통해 도심 수목원에서의 경관감상 또는 산책과 같은 활동이 도시민의 생리적 안정감을 향상시키는데 효과가 있음을 알 수 있었다.

4-10 Hz 빛과 소리자극 후 단기기억력 및 자율신경심장기능의 변화 - 예비연구 - (The Changes of Short-Term Memory and Autonomic Neurocardiac Function after 4-10Hz Sound and Light Stimulation - A Pilot Study -)

  • 이승환;김진환;박중규;이경욱;양대현;홍근영;채정호
    • 수면정신생리
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    • 제11권1호
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    • pp.29-36
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    • 2004
  • 목 적 : 본 연구는 $4{\sim}10\;Hz$의 빛과 소리자극이 인체의 단기기억력 및 긴장이완에 어떠한 영향을 주는지 관찰하기 위한 예비연구로 시행되었다. 방법:총 10명의 대상을 무작위로 동기화된 파형의 빛과 소리를 가한 처치군(R 군)과 동기화되지 않은 무작위 파형의 빛과 소리를 가한 허위군(P 군)으로 분류하고, 하루 15분씩 5일간 빛과 소리 자극을 가하였다. 단기기억력을 측정하기위한 척도, 불안 척도 그리고 자율신경심장 기능 검사 등을 시행하였다. 2일간 휴식 후 R군과 P군을 교차하여 5일간 같은 실험을 반복하였다. 결 과:R군에서 빛과 소리자극 1회 적용 후 단기기억력의 유의미한 향상이 관찰되었다. 자율신경심장기능 검사에서는 R군에서 유의미한 이완 효과가 관찰되었다. 결 론:이 연구 $4{\sim}10\;Hz$의 빛과 소리자극이 단기기억 및 긴장이완과 연관됨을 암시한다. 향후 실험대상수를 늘려 예비연구결과를 확인함이 필요하다.

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생애주기에 따른 스트레스 관리 프로그램에 대한 고찰 -1993년부터 1996년까지의 외국문헌을 중심으로- (Literature Review on the Stress Management Programs throughout Life - span: By foreign research for 1993-1996)

  • 윤손녕;최정숙;이경숙
    • 지역사회간호학회지
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    • 제8권2호
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    • pp.178-196
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    • 1997
  • The purpose of this study is to identify the kind, the frequency, and the type of Stress Management Program(SMPs) throughout life-span used foreign, recent research. The period of this study was from July 1 to Dec. 10, 1997. The data were collected through Medline using two concepts: stress management programs and life-span. The number of these research were 106 and thirty-one experimental researches that were tested the effectiveness of SMPs throughout life span were selected. The data were analysed by the kind, frequency, and life-span. The results were as follows: 1. The kind and frequency of SMP : The total number of the kind of SMP were twenty-two. The most used SMP was relaxation therapy, 22 out of 31. The second biofeedback was 10, the third, cognitive behavior program was 9, the fourth, nutrition and diet, and education were 7. The others were coping skill(4), cognitive therapy(4), breathing(4), imagery(3), autogenic training(3), sleep and rest(2), meditation(2), information(2), desensitization(2), hypnosis(2), behavior therapy(1), time management (1), visualization(I), yoga(I), diversion(1), and problem solving skill. 2. Throughout life-span: Most SMPs were applied to adolescents, young adults, and middle-adults. Other subjects could not be found under the schooler. 3. The type of SMPs : 28(90.3%) out of 31 research used combined-SMP : two-combined SMP, 5: three-combined SMP, twelve: four-combined SMP, seven: five-combined SMP. 4. Afterward, further study such as meta-analysis are needed in order to identify effective ness of the SMPs.

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턱관절장애 유무에 따른 깨물근, 목빗근의 두께 및 근긴장도, 최대 입벌림 범위의 비교 및 상관성 연구 (Comparison and Correlation on Muscle Thickness and Muscle Tone of Masseter Muscle and Sternocleidomastoid Muscle, Maximum Jaw Opening in Subjects With and Without Temporomandibular Joint Disorder)

  • 이근효;천승철
    • 대한통합의학회지
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    • 제8권3호
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    • pp.93-101
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    • 2020
  • Purpose : Temporomandibular joint disorder (TMJD) is often accompanied by pain and limited range of motion of the jaw joint, which affect patients' quality of life and result in hypertrophy or hyperactivity of the muscles around the jaw joint. In this study, we compared the muscle thickness and tone of the masseter and sternocleidomastoid (SCM) muscles and the jaw range of motion in individuals with and without TMJD. Correlation comparison was performed on the results of the TMJD group. Methods : This study included 40 patients; 20 patients were assigned to an experimental group (TMJD group) and 20 to a control group (non-TMJD group). Ultrasonography, myotonometry, and measurements performed with digital Vernier calipers were used to determine the changes in muscle thickness, muscle tone, and maximum jaw opening, respectively. The independent t-test was used for intergroup comparison of data, and Pearson correlation coefficients were used to compare correlations in the TMJD group results. Results : We observed a significant intergroup difference in the masseter and SCM thickness during the relaxed and clenched phases (p<.05). A significant intergroup difference was also observed in maximum jaw opening (p<.05). With regard to muscle tone, we observed a significant intergroup difference in frequency (p=.011) and stiffness (p=.011) of the masseter, as well as in the frequency (p=.009) and stiffness (p=.026) of the SCM. We observed a moderate negative correlation (r=-.524) between maximum jaw opening and the frequency of the masseter. Additionally, we observed a moderately negative correlation between jaw opening and muscle stiffness (r=-.321). Conclusion : Planning exercise programs to treat patients with TMJD who present with pain should focus on efforts to reduce muscle thickness and achieve muscle relaxation (to reduce muscle tension) for improved jaw range of motion.

자성재료를 이용한 광대역 전자파 흡수체 설계 연구 (Design of Wideband Electromagnetic Wave Absorber Using Magnetic Materials)

  • 김동영;윤석수
    • 한국자기학회지
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    • 제22권6호
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    • pp.210-215
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    • 2012
  • 단층형 전자파 흡수체의 흡수 성능은 입사파의 반사 손실(return loss)이 최대가 되는 두께 정합 조건 및 주파수 정합 조건에서 최적화 된다. 본 연구에서는 재료의 복소 투자율과 복소 유전율에 의존하는 전송선 이론을 적용하여 광대역 흡수체의 정합 조건을 계산하였다. 그 결과 주파수에 따른 복소 투자율 감소 특성이 두께 정합 조건을 광대역으로 확대하는 효과를 지니기 때문에 광대역 전자파 흡수체에 자성 재료가 이용될 수 있다는 것을 알 수 있었다. 따라서 향후 확대될 EMC(Electromagnetic compatibility) 규격을 대비한 차세대 광대역 전자파 흡수체를 만들기 위하여 현재 사용되고 있는 NiZn 페라이트 소결체 보다 포화 자화량이 크고 유전율 값이 작은 자성 재료들을 사용하여야 한다는 것을 보였다.

칼슘 및 칼륨이온이 흰쥐 자궁근(子宮筋) 활동전압(活動電壓)에 미치는 영향(影響) (Effects of $Ca^{2+}$ and $K^+$ on the Spike Action Potentials in Oxytocin-induced Uterine Contractions)

  • 김철수;김기환
    • The Korean Journal of Physiology
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    • 제20권1호
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    • pp.43-52
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    • 1986
  • The influences of extracellular $Ca^{2+}\;and\;K^+$ upon the spike action potentials were studied in isolated uterine strips of rat. Regular, rhythmic uterine contractions were induced by the administration of oxytocin$(0.2{\sim}0.5\;I.U.)$, and recorded with force transducer. Spike action potentials were extracellularly measured by use of suction electrode, and compared with those recorded intracellularly by glass microelectrode. The results obtained were as follows : 1) The frequency and duration of spike bursts, and the number of spikes in a burst could be analyzed by use of both methods. But the absolute values of membrane potential were not measurable with the suction electrode. 2) The duration of contraction$(CD_{90};\;the\;duration\;of\;90%\;relaxation)$ was lengthened from the control 17.0 sec to 20.6 sec, in parallel with the increase of spike number from the control 21 to 26, as the increase in $Ca^{2+}$ concentration from 2 to 4 mM. 3) The amplitude and frequency of contractions were gradually decreased, simultaneously with the decrease in the number of spikes in a burst, when the $Ca^{2+}-antagonist$, verapamil was administered cumulatively. 4) The number of spikes was changed from the control 15 to 7, in cabs of the administration of ver)'low dose of verapamil$(10^{-6}\;g/l)$. 5) Increase in the numbers of spike bursts was well matched to the increase in frequency of contractions when extracellular $K^+$ was increased.

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Epoxy/BaTiO3 (SrTiO3) composite films and pastes for high dielectric constant and low tolerance embedded capacitors fabrication in organic substrates

  • Paik Kyung-Wook;Hyun Jin-Gul;Lee Sangyong;Jang Kyung-Woon
    • 한국마이크로전자및패키징학회:학술대회논문집
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    • 한국마이크로전자및패키징학회 2005년도 ISMP
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    • pp.201-212
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    • 2005
  • [ $Epoxy/BaTiO_3$ ] composite embedded capacitor films (ECFs) were newly designed fur high dielectric constant and low tolerance (less than ${\pm}15\%$) embedded capacitor fabrication for organic substrates. In terms of material formulation, ECFs are composed of specially formulated epoxy resin and latent curing agent, and in terms of coating process, a comma roll coating method is used for uniform film thickness in large area. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ composite ECF is measured with MIM capacitor at 100 kHz using LCR meter. Dielectric constant of $BaTiO_3$ ECF is bigger than that of $SrTiO_3$ ECF, and it is due to difference of permittivity of $BaTiO_3\;and\;SrTiO_3$ particles. Dielectric constant of $BaTiO_3\;&\;SrTiO_3$ ECF in high frequency range $(0.5\~10GHz)$ is measured using cavity resonance method. In order to estimate dielectric constant, the reflection coefficient is measured with a network analyzer. Dielectric constant is calculated by observing the frequencies of the resonant cavity modes. About both powders, calculated dielectric constants in this frequency range are about 3/4 of the dielectric constants at 1 MHz. This difference is due to the decrease of the dielectric constant of epoxy matrix. For $BaTiO_3$ ECF, there is the dielectric relaxation at $5\~9GHz$. It is due to changing of polarization mode of $BaTiO_3$ powder. In the case of $SrTiO_3$ ECF, there is no relaxation up to 10GHz. Alternative material for embedded capacitor fabrication is $epoxy/BaTiO_3$ composite embedded capacitor paste (ECP). It uses similar materials formulation like ECF and a screen printing method for film coating. The screen printing method has the advantage of forming capacitor partially in desired part. But the screen printing makes surface irregularity during mask peel-off, Surface flatness is significantly improved by adding some additives and by applying pressure during curing. As a result, dielectric layer with improved thickness uniformity is successfully demonstrated. Using $epoxy/BaTiO_3$ composite ECP, dielectric constant of 63 and specific capacitance of 5.1nF/cm2 were achieved.

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돼지의 세균성 위장관 질환에 따른 평활근 기능 이상에 대한 침술의 효과 (The Effect of Acupuncture on the Intestinal Smooth Muscle Dysfunction Caused by Enteric Bacterial Infection in Weaning Piglet)

  • 김태완;나준호;성태식;강정우;남치주;최민철;윤여성;양일석
    • 대한수의학회지
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    • 제43권3호
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    • pp.415-421
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    • 2003
  • It is now generally accepted that acupuncture is effective in diarrhea caused by bacterial infection. However, its effect on the intestinal smooth muscle dysfunction is not clear. Therefore, we investigated the effect of acupuncture therapy at Jiao-chao (GV-1) on the intestinal muscle dysfunction in weaning piglets orally infected by Escherichia coli. The animals are divided into four groups; 1) E. coli + no-treatment, 2) E. coli + antibiotic, 3) E. coli + acupuncture, 4) normal group. In the three E. coli infected groups, low frequency electrical field stimulation (EFS, 1 Hz) provoked triphasic responses composed of initial relaxation followed by on-contraction and off-contraction. While in the normal group, EFS (1Hz) induced biphasic responses composed of relaxation during the stimulation and off-contraction. At the high frequency (16Hz) EFS, both on-contraction and off-contraction of the E. coli + antibiotic, E. coli + acupuncture and the normal group were larger than those of the E. coli + no-treatment group. In the non-adrenergic non-cholinergic (NANC) condition, only biphasic responses occurred to EFS in all experimental groups and the off-contraction of E. coli + antibiotic, E. coli + acupuncture and the normal group were larger than those of the E. coli + no-treatment group. The response to carbachol of those three groups was also significantly greater than that of the E. coli + no-treatment group. These results suggest that acupuncture is as effective as antibiotic in the dysfunction of colonic circular muscle caused by E. coli infection. The maintenance of contractile neuromuscular transmission seems to be involved in the mechanism of the acupuncture effects on diarrhea.