• Title/Summary/Keyword: High-Frequency Components

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A Clinical Study on Blood Lipids as a Risk Factor of Cerebral Infarction (뇌경색 위험인자로서의 혈중 지질에 대한 임상적 연구)

  • Son, Yeon-Hui;Lee, Sang-Hee;Kim, Jae-Kyu;Jeong, Hyun-Yun;Kim, Young-Kyun;Kwon, Jung-Nam
    • Journal of Pharmacopuncture
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    • v.11 no.4
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    • pp.49-58
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    • 2008
  • Objective The purpose of this case-control study was done to examine the relationship among the acute brain infarction, silent brain infarction and blood lipids. Methods We compared the components of blood lipids among acute brain infarction patients group (n=99), silent brain infarction patients group(n=101) and controls group (n=153). The analysis of the data was done by Frequency Analysis, one-way ANOVA, Post Hoc Test(Duncan), Pearson's Correlation. Results The results were as follows. High density lipoprotein cholesterol(HDL-Chol) was significantly lower in patients of acute brain infarctions group. The blood levels of total cholesterol(T-Chol) was significantly higher in patients of silent brain infarctions. A study on the relationship among the significant variables ; In T-Chol and HDL-Chol, DM(No=0, Yes=1) and Age, they had positive correlation each other. Between Sex(Female=0, Male=1) and HDL-Chol, Age and HDL-Chol, DM and HDL-Chol, they had negative correlation each other. Conclusions These results suggest that low HDL-Chol may be risk factor of acute brain infarction.

The Effects of Qigong Position on Electroencephalogram (기공(氣功) 자세(姿勢)가 뇌파에 미치는 영향)

  • Jung, Dae-Sun;Han, Chang-Hyun;Park, Soo-Jin;Lee, Sang-Nam;Park, Ji-Ha
    • Korean Journal of Oriental Medicine
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    • v.16 no.1
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    • pp.157-171
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    • 2010
  • This study aimed to investigate the effect of four common types of Qigong position (standing, sitting, supine, and horse-riding position) on the autonomic nervous system. Thirty healthy subjects participated in this study once a week for four weeks. Electroencephalogram (EEG) was measured three times (before, during, and after the position) while the subject maintained one of four positions for ten minutes. There were significant changes in HRV components compared with EEG power spectra in the standing position. Especially, the ratio of low-to-high frequency (LF/HF) which represents a state of balance of autonomic nervous system was increased. In the sitting position, $\beta$ wave which reflects a state of alert consciousness was increased and both the sympathetic and parasympathetic nerves were activated. On the other hand, in the spine position, $\theta$ wave which signifies a state of relaxation was increased and heart rate (HR) was decreased. Activation of sympathetic and parasympathetic nerves was also observed in this position. Significant increases of indices related to awakening and concentration were observed accompanied by increase of HR and a sympathetic nerve was activated in the riding-horse position. In the present study, it was shown that each Qigong position caused various and significant changes in autonomic nervous system. It would be expected that these results can be applied in the choice of appropriate Qigong position according to objective of Qigong therapy although it is remained to further evaluate the effects of long-term maintenance of Qigong positions and repeated Qigong training.

Pyroshock and Vibration Isolation using SMA Mesh Washer Isolator (형상기억합금 메쉬 와셔 절연계의 파이로 충격 및 진동 절연 시험)

  • Youn, Se-Hyun;Jang, Young-Soon;Han, Jae-Hung
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.3
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    • pp.307-313
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    • 2009
  • In general, pyroshock is generated from the actuation of separation devices for several stage, fairing, and satellite separation in the flight of a launch vehicle. During these events, transient vibration phenomenon called pyroshock, which shows large acceleration in the high frequency range, occurs and it can result in the malfunction of electronic components which is equipped inside the launch vehicle or satellite. In this paper, mesh washer isolators made out of SMA were introduced for the isolation of pyroshock. One type of isolator primarily used pseudoelastic characteristics of SMA and the other type of isolator used shape memory effect of SMA. For the study of basic load-displacement relationship of each SMA isolator, compressive loading tests were performed and the results showed the capability of the isolator itself. Pyroshock isolation tests were followed and verified the outstanding isolation performance of isolator. In addition, random vibration tests were also performed and checked the dynamic characteristics of each SMA isolator.

Design of n Miniaturized LTCC Power Detector for the Tx Power Control in Wireless Communication System (무선통신시스템 송신측 제어를 위한 초소형 LTCC 전력검출부의 설계)

  • Hwang, Mun-Su;Lim, Jong-Sik;Yang, Gyu-Ryeol;Ahn, Dal
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.3
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    • pp.621-627
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    • 2008
  • This paper presents a compact and miniaturized power detector utilizing low temperature co-fired ceramics(LTCC) technology for the application in wireless handset system to monitor the transmitting power at the frequency of 824-849MHz. The proposed power detector is composed of detector diode, lumped components for matching network, and LTCC stripline coupler based on LTCC substrate technology. A 20dB LTCC stripline direction coupler is designed and implemented with many bending section in order to reduce the practically occupied area for miniaturization. A zero bias schottky diode is adopted for detector design because of its high speed operation with minimized loss. The measured performances of fabricated detector agree well with the predicted results with a good linearity within the effective input RF power range.

Hypermethylation Status of E-Cadherin Gene in Gastric Cancer Patients in a High Incidence Area

  • Rashid, Haroon;Alam, Khursheed;Afroze, Dil;Yousuf, Adfar;Banday, Manzoor;Kawoosa, Fizalah
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.6
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    • pp.2757-2760
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    • 2016
  • Gastric cancer (GC) is the fourth most prevalant cancer and the second leading cause of cancer-related mortality worldwide. As in other cancers gastric carcinogenesis is multifactorial involving environmental, genetic and epigenetic components. Epigenetic silencing due to hypermethylation of tumour suppressor genes is one of the key events in gastric carcinogenesis. This study was aimed to analyse the hypermethylation status of the E-Cadherin (CDH1) gene promoter in GCs in the ethnic Kashmiri population. In this study a total of 80 GC patients were recruited. Hypermethylation in tumour tissue was detected by methylation specific PCR (MS-PCR). Hypermethylation of CDH1 promoter was observed in 52 (65%) of gastric carcinoma cases which was significantly much higher than adjacent normal tissue [$p{\leq}0.0001$]. Further the frequency of CDH1 promoter methylation was significantly different with intestinal and diffuse types of gastric cancer [55.7% vs 82.1%; p<0.05]. Moreover females and cases with lymph node invasion had higher frequencies of CDH1 hypermethylation [$P{\leq}0.05$]. Thus the current data indicate a vital role of epigenetic alteration of CDH1 in the causation and development of gastric cancer, particularly of diffuse type, in our population.

Comparison of Fatigue Damage Models of Spread Mooring Line for Floating Type Offshore Plant (부유식 해양플랜트 다점 계류라인의 피로손상모델 비교)

  • Park, Jun-Bum;Kim, Kookhyun;Kim, Kyung-Su;Ko, Dae-Eun
    • Journal of Ocean Engineering and Technology
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    • v.27 no.5
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    • pp.63-69
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    • 2013
  • The mooring lines of a floating type offshore plant are known to show wide banded and bimodal responses. These phenomena come from a combination of low and high frequency random load components, which are derived from the drift-restoring motion characteristic and wind- sea, respectively. In this study, fatigue models were applied to predict the fatigue damage of mooring lines under those loads, and the result were compared. For this purpose, seven different fatigue damage prediction models were reviewed, including mathematical formula. A FPSO (floating, production, storage, and offloading) with a $4{\times}4$ spread catenary mooring system was selected as a numerical model, which was already installed at an offshore area of West Africa. Four load cases with different combinations of wave and wind spectra were considered, and the fatigue damage to each mooring line was estimated. The rain flow fatigue damage for the time process of the mooring tension response was compared with the results estimated by all the fatigue damage prediction models. The results showed that both Benasciutti-Tovo and JB models could most accurately predict wide banded bimodal fatigue damage to a mooring system.

Composite PEO-Coatings as Defence Against Corrosion and Wear: A Review

  • Gnedenkov, S.V.;Sinebryukhov, S.L.;Sergienko, V.I.;Gnedenkov, A.S.
    • Corrosion Science and Technology
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    • v.18 no.5
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    • pp.212-219
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    • 2019
  • This paper reviews recent approaches to develop composite polymer-containing coatings by plasma electrolytic oxidation (PEO) using various low-molecular fractions of superdispersed polytetrafluoroethylene (SPTFE). The features of the unique approaches to form the composite polymer-containing coating on the surface of MA8 magnesium alloy were summarized. Improvement in the corrosion and tribological behavior of the polymer-containing coating can be attributed to the morphology and insulating properties of the surface layers and solid lubrication effect of the SPTFE particles. Such multifunctional coatings have high corrosion resistance ($R_p=3.0{\times}10^7{\Omega}cm^2$) and low friction coefficient (0.13) under dry wear conditions. The effect of dispersity and ${\xi}$-potential of the nanoscale materials ($ZrO_2$ and $SiO_2$) used as electrolyte components for the plasma electrolytic oxidation on the composition and properties of the coatings was investigated. Improvement in the protective properties of the coatings with the incorporated nanoparticles was explained by the greater thickness of the protective layer, relatively low porosity, and the presence of narrow non-through pores. The impedance modulus measured at low frequency for the zirconia-containing layer (${\mid}Z{\mid}_{f=0.01Hz}=1.8{\times}10^6{\Omega}{\cdot}cm^2$) was more than one order of magnitude higher than that of the PEO-coating formed in the nanoparticles-free electrolyte (${\mid}Z{\mid}_{f=0.01Hz}=5.4{\times}10^4{\Omega}{\cdot}cm^2$).

Retouching Method for Watercolor Painting Effect Using Mean Shift Segmentation (Mean Shift Segmentation을 이용한 수채화 효과 생성 기법)

  • Lee, Sang-Geol;Kim, Cheol-Ki;Cha, Eui-Young
    • Journal of the Korea Society of Computer and Information
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    • v.15 no.9
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    • pp.25-33
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    • 2010
  • We propose a retouching method that converts a general photography to a watercolor painting image using bilateral filtering and mean shift segmentation which are mostly used in image processing. The first step is to weaken high frequency components of the image, while preserving the edge of image using the bilateral filtering. And after that we perform DoG(Difference of Gradient) edge extraction and mean shift segmentation respectively from the bilateral filtered image. The DoG edge extraction is performed using luminance component of the image whose RGB color space is transformed into CIELAB space. Experimental result shows that our method can be applied to various types of image and bring better result, especially against the photo taken in daylight.

Behavioral and cardiac responses in mature horses exposed to a novel object

  • Lee, Kyung Eun;Kim, Joon Gyu;Lee, Hang;Kim, Byung Sun
    • Journal of Animal Science and Technology
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    • v.63 no.3
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    • pp.651-661
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    • 2021
  • This study aimed to investigate whether breed, sex, and age affected temperament differently (more or less neophobic) in mature horses during a novel object test. The study included Jeju crossbred (n = 12, age = 9.42 ± 4.57 y), Thoroughbred (n = 15, age = 10.73 ± 3.09 y), and Warmblood horses (n = 12, age = 13.08 ± 3.55 y) with the females (n = 22, age = 11.36 ± 4.24 y) and geldings (n = 17, age = 10.65 ± 3.66 y). Jeju crossbreds (Jeju horse × Thoroughbred) are valuable considering their popular usage in Korea, but limited studies have explored temperament of Jeju crossbred horses. A trained experimenter touched the left side of the neck with a white plastic bag (novel object). The test ended when the horse stopped escape response and heart rate (HR) dropped to baseline. Behavioral score and escape duration were measured as behavioral variables. Multiple variables related to HR and heart rate variability (HRV) were measured to reflect emotional state. These included basal HR (BHR), maximum HR (MHR), delay to reach maximum heart rate (Time to MHR), standard deviation of beat-to-beat intervals (SDNN), root mean square of successive differences (RMSSD), and ratio of low to high frequency components of a continuous series of heartbeats (LF/HF). Statistics revealed that Thoroughbreds had significantly higher behavioral scores, and lower RMSSD than Jeju crossbreds (p < 0.05), suggesting greater excitement and fear to the novel object in Thoroughbreds. None of the behavioral or cardiac parameters exhibited sex differences (p < 0.05). Age was negatively correlated with SDNN and RMSSD (p < 0.05), indicating that older horses felt more anxiety to the novelty than younger horses. Thoroughbreds and females had distinct correlations between behavioral and HRV variables in comparison with other groups (p < 0.05), implying that escape duration might be a good indicator of stress, especially in these two groups. These results are expected to improve equine welfare, safety and utility, by providing insights into the temperament of particular horse groups, to better match reactivity levels with specific functions.

Physical nature of the eclipsing δ Scuti star AO Serpentis

  • Park, Jang-Ho;Lee, Jae Woo;Hong, Kyeongsoo;Koo, Jae-Rim;Kim, Chun-Hwey
    • The Bulletin of The Korean Astronomical Society
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    • v.44 no.1
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    • pp.86-86
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    • 2019
  • We present BV photometric observations and high-resolution spectra of AO Ser, which were obtained at the Mt. Lemmon Optical Astronomy Observatory (LOAO) and the Bohyunsan Optical Astronomy Observatory (BOAO), respectively, in 2017. The radial velocities (RVs) for both components were measured, and the effective temperature of the primary star was found to be $T_{eff,1}=8,820{\pm}62K$ by a comparison of the observed spectra and the Kurucz models. A unique set of fundamental parameters of AO Ser were derived for the first time by a simultaneous analysis of the light and RV curves. The results indicate that our program target is a semi-detached eclipsing system with values of $M_1=2.06{\pm}0.11M_{\odot}$ and $M_2=0.41{\pm}0.03M_{\odot}$, $R_1=1.54{\pm}0.03R_{\odot}$ and $R_2=1.30{\pm}0.02R_{\odot}$, and $L_1=12.9{\pm}0.2L_{\odot}$ and $L_2=0.9{\pm}0.3L_{\odot}$. We applied multiple frequency analyses to the eclipse-subtracted light residuals. As a result, two frequencies of $f_1=21.85151days^{-1}$ and $f_2=23.48405days^{-1}$ were detected and their pulsation constants were calculated to $Q_1=0.0344days$ and $Q_2=0.0320days$. The pulsational characteristics and the position in the HR diagram demonstrate that the primary star is a ${\delta}$ Sct pulsator.

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