• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.904-907
• /
• 2002

Optical disk drive device is improved in rotating speed for faster data reading. In the case of CD-ROM, rotating speed is over 10000 rpm in the practical use. As a result of high rotating speed, unexpected effects as like increasing disk fluctuation and acoustic noise are raised by the air friction on the rotating disk and the eccentricity of rotating parts. The overall acoustic noise of running CD-ROM could be classified into two different characterized noise. The first is the structural-borne noise which is generated from vibrating solid body. By the reason, the signal of structural borne noise has very similar to the signal of surface vibrating one. It has dense noise energy at specific frequency region. The other is the air-borne noise which is generated from turbulence or vortex caused by friction between disk and air. The signal of air-borne noise has no dominant peak point at acoustic pressure-frequency domain. The noise energy is widely distributed while comparatively high and large frequency region. The structural-borne noise could be reduced by reducing vibration of structure and in addition it's target reducing frequency is narrow. However the air-borne noise reduction is effectively needed of enclosing method for the noise source located near the disk surface because it is difficult to define target frequency point. In this study, the acoustic noise at driving CD-ROM is classified by the sides of it's character and tried to reduce the overall acoustic noise.

• International Journal of Control, Automation, and Systems
• /
• 제4권3호
• /
• pp.325-332
• /
• 2006

The dynamic responses of human standing postural control were investigated when subjects were exposed to long-term horizontal vibration. It was hypothesized that the motion of standing posture complexity mainly occurs in the mid-sagittal plane. The motor-driven support platform was designed as a source of vibration. The AC Servo-controlled motors produced anterior/posterior (AP) motion. The platform acceleration and the trunk angular velocity were used as the input and the output of the system, respectively. A method was proposed to identify the complexity of the standing posture dynamics. That is, during AP platform motion, the subject's knee, hip and neck were tightly constrained by fixing assembly, so the lower extremity, trunk and head of the subject's body were individually immovable. Through this method, it was assumed that the ankle joint rotation mainly contributed to maintaining their body balance. Four subjects took part in this study. During the experiment, the random vibration was generated at a magnitude of $0.44m/s^2$, and the duration of each trial was 40 seconds. Measured data were estimated by the coherence function and the frequency response function for analyzing the dynamic behavior of standing control over a frequency range from 0.2 to 3 Hz. Significant coherence values were found above 0.5 Hz. The estimation of frequency response function revealed the dominant resonance frequencies between 0.60 Hz and 0.68 Hz. On the basis of our results illustrated here, the linear model of standing postural control was further concluded.

• 대한한방내과학회지
• /
• 제36권4호
• /
• pp.547-561
• /
• 2015

Objectives In this study, we divided Korean asthma patients into excess syndrome or deficiency syndrome groups according to clinical phenotype. Genetic analysis was conducted to investigate the association of exonic SNPs in the CD46 gene polymorphism with the clinical phenotype based on the differentiation syndrome of the bronchial asthma patients.Methods There were 95 healthy patients (control group) and 53 asthma patients. (The deficiency syndrome group included 24 and the excess syndrome group 29). We searched the exonic areas of the CD46 gene in the NCBI website SNPs with <0.01 minor allele frequency (MAF) and <0.01 heterozygosity. We finally selected two SNPs: rs138843816, Ser13Phe and rs7144, 3’-UTR. Hardy-Weinberg equilibrium was calculated using SNPStats.Results There were significant differences in the codominant 1 model and the dominant model between the healthy group and the asthma group. There were significant differences between deficiency syndrome group and the excess syndrome group in the genotype frequencies and in the codominant 1 model, the dominant model, and the log-additive model. The allele frequency of rs7144C showed a significant difference between the deficiency syndrome group and the excess syndrome group. Two-SNP haplotype analysis showed a significant difference in frequency in the deficiency syndrome group and in the excess syndrome group. There were significant differences between the healthy group and the excess syndrome group in the codominant 1 model, the dominant model, and the log-additive model. The frequency of the rs7144 C allele exhibited a significant difference in the demonstration. SNP haplotype analysis between the healthy group and the excess syndrome group showed a significant difference in the frequency of the CT haplotype and the CC haplotype.Conclusions The results indicate that two CD46 SNPs (rs138843816, Ser13Phe and rs7144, 3′–UTR) might be associated with the symptomatic excess syndrome in Korean asthma patients.

• 지구물리와물리탐사
• /
• 제11권2호
• /
• pp.116-126
• /
• 2008

가스 하이드레이트의 탐사에서 탄성파 진폭과 주파수 특성은 가스 하이드레이트의 부존 여부에 대한 매우 중요한 판단 근거이다. 본 연구에서 탄성파 진폭특성은 탄성파 수치모델링 기법을 이용하여 음원 주파수 및 산란체의 크기에 따른 변화 양상을 파악하고자 하였다. 일반적으로 진폭에 큰 영향을 미치는 산란은 음원의 주파수 제곱에 비례하고 산란 이상체의 체적에 비례한다. 음원의 주파수가 높아질수록 가스 하이드레이트 지층에서의 산란이 심하여 BSR이 잘 나타나지 않는 반면 음원의 주파수가 낮아질수록 가스 하이드레이트 지층의 진폭공백대 특성이 잘 나타나고 또한 하부의 BSR이 보다 뚜렷히 보이나 해상도가 낮아지게 된다. 가스 하이드레이트 지층 하부의 Free-Gas층을 통과한 반사파는 고주파수 성분이 감쇠되어 저주파수 성분이 우세해지고, Free-Gas로 인하여 나타나는 BSR의 진폭은 극성역전현상이 발생되며 이것은 가스 하이드레이트 지층의 존재와 분포를 판단하는 중요한 인자가 된다. 탄성파 주파수 특성 분석은 Wavelet Transform을 이용하여 시간에 따른 탄성파동의 주파수 변화를 관찰하는 방법을 사용하였다. 탄성파 모형 실험 자료에 대하여 적용한 결과 Free-Gas층에 대비되는 공기층을 통과하여 반사된 탄성파의 주파수는 고주파수 성분이 상당히 감쇠되었음을 관찰할 수 있었다.

• 수산해양기술연구
• /
• 제8권1호
• /
• pp.14-22
• /
• 1972

For the development of acoustic fishing method, the noises of fishes have been recorded and analy/'ed by many scientists. Some specimens of fishes were selected as such Cyprinus carpio, Ctenopharyngodon idellus Carassius carassius, and pagrosol1ms major in this experiment. The noises such as feeding noise, driving away noise, jumping noise and fi llip noise were recorded by the tape recorder, Sony Model 262, through the underwa te r microph I one, Oki ST 6582, and analyzed in frequencies bv octave band analyzer, Rion SA-55, and sound pressure level of source by sound level meter, Rion NA-opNN The supplied feed was placed within 5em apart from the hydrophone. The result of analyzed noises were as follow. Cyprinus carjJio; Feeding noise 250- 500 cps, 92- 99 dB Driving away noise 125-2, 000 eps, 101-112 dB Jumping noise 125-2, 000 eps, 99-116.5 dB Ctenopharyngodon idcllus; Driving away noise 125-1, 000 cps, 96-109 dB Carassius carassius; Feeding noise 250- 500 cps, 91. 5- 99.5 dB Driving away noise 125-1, 000 eps, 99-108 dB Carassius auratus Feeding noise 250 eps, 94-101 dB Driving away noise 125-1, 000 cps, 98-110 dB Pagrosomus major Feeding noise 230-500 cps, 90-101 dB Fillip noise 500 cps, 98-108 dB (1) Feeding noise was produced as like as snap noise of twig and gulping down saliva noise in human and dominant frequency range of the noise is 250-500 cps and noise level 90-101 dB. (2) It was found that feeding noise were not a monotonic but a complex tones though fish took the same food. (3) Driving away noise was produced not so keen and the wave form of the noise is rising very sharp and big amplitude in the oscillograph. Dominant frequency range of this noise was about 150-1, 000 cps and noise level 96-112 dB except thut of carp. (4) The frequency of snapper's fillip noise, when it produced by caudal fin in swimming at the surface of water, was 500 cps and noise level 93-108 dB snd that of jumping noise of carp about 150-2, 000 cps and noise level 99-116.5 dB.

• 한국지구과학회지
• /
• 제31권6호
• /
• pp.584-599
• /
• 2010

우리나라의 7개 라디오존데 관측소의 2년간 관측자료를 이용하여 레이더 빔의 진행과 관련된 과대굴절, 빔갇힘의 발생빈도를 통계 분석하였다. 과대굴절과 빔갇힘의 발생빈도는 백령도가 다른 지역에 비해 높았으며 오산과 광주는 시간대별 변화가 가장 크게 나타났다. 세부적인 빔갇힘 발생빈도에서는 고산을 제외한 모든 관측소에서 지표 빔갇힘의 발생이 우세하였으며 흑산도, 고산은 상층 빔갇힘의 비율이 다른 관측소들에 비해 높았다. 계절변동에서는 전체적으로 여름이 겨울에 비해 빔갇힘 발생비율이 높았다. 빔갇힘의 발생은 봄, 가을 겨울에 백령도가 가장 우세하였으며 여름은 포항으로 나타났다. 오산과 광주는 모든 계절에서 발생빈도가 가장 적었다. 빔갇힘의 월별분포에서는 오산과 광주를 제외한 관측소에서는 00 UTC와 12 UTC 간에 큰 차이가 없었다. 광주, 흑산도, 고산은 월별 총 발생비율의 최대값이 60%를 넘지 않았으며 전체적인 발생비율도 다른 관측소들에 비해 낮게 나타났다. 빔갇힘 발생가능 레이더 관측 고도각 조사에서 KSN이 4개 고도각으로 고도각수에서 최고로 나타났으며 JNI가 고도각 $1.2^{\circ}$로 고도각에서 최고로 나타났다. 전체적으로는 $1.0^{\circ}$ 근처에서 최대 고도각이 나타났다.

• 한국환경복원기술학회지
• /
• 제19권1호
• /
• pp.61-71
• /
• 2016

The purpose of the research is to identify the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria as leguminous woody plants for the cut-slope revegetation. To investigate the coverage ratio and appearance frequency, we divided Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria into five treatment groups with various quantities of $0.0g/m^2$, $1.0g/m^2$, $2.4g/m^2$, $3.8g/m^2$, and $5.2g/m^2$. For each treatment group, we mixed the identical quantities of herbaceous flowers (Lotus corniculatus var. japonicus, Dianthus sinensis, Aster yomena and Pennisetum alopecuroides) seeds and cool-season turfgrasses (Festuca arundinacea and Poa pratensis) seeds. In this result, as the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria increased in the spray, the coverage ratio for leguminous woody plants appeared to increase whereas the coverage ratio decreased in herbaceous flowers and cool-season turfgrasses. However, when the seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria exceeded $3.8g/m^2$ in the spray, the coverage ratio of leguminous woody plants rather decreased compared to four treatment groups less than $3.8g/m^2$ seeding ratio. Based on the longitudinal data of coverage ratio in five treatment groups, we observed the gradual process of a short-term succession in which the dominant species shifted in the following order: First, cool-season turfgrasses; Second, herbaceous flowers; Third, leguminous woody plants. Comparing the appearance frequency of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria, Lespedeza cyrtobotrya appeared more frequent in 2014 whereas Indigofera pseudo-tinctoria appeared to be relatively more frequent in 2015. As a result, Indigofera pseudo-tinctoria was discovered to be a dominant species among woody plants. In this study, we observed that the optimal seeding quantity of Lespedeza cyrtobotrya and Indigofera pseudo-tinctoria was $2.4g/m^2{\sim}3.8g/m^2$. Moreover, the coverage ratio of 29.1%~35.4% and appearance frequency of 4.6plants~5.8plants were found in the condition of optimal seeding quantity.

• 생물정신의학
• /
• 제20권4호
• /
• pp.166-178
• /
• 2013

Objectives Alteration of epigenetic effects of testosterone during early development was suggested as an ancillary mechanism for the genesis of schizophrenia. EEG coherence was thought to be a marker for cerebral laterality of which important determinant was testosterone during early development. We studied sex-related differences of EEG coherences between patients with schizophrenia and controls to examine the sex effects in the genesis of schizophrenia. Methods EEG was recorded in 35 patients with schizophrenia and 46 healthy controls in the eyes closed resting state. Pair-wise EEG coherences were calculated over delta, theta, alpha, beta and gamma frequency bands. To examine the differences of EEG coherence according to sex in each group, ANCOVA was performed using Statistical Analysis system (SAS, Ver 9.3) and R (Ver 2.15.2). Results Healthy control males showed more increased right intrahemispheric coherences than healthy control females in delta, theta, alpha and beta frequency bands. In patients with schizophrenia, this male dominant pattern in right intrahemispheric coherences was attenuated especially in alpha and beta bands. Healthy control females showed more increased interhemispheric coherences than healthy control males in delta, theta, beta and gamma frequency bands. In patients with schizophrenia, these female dominant patterns in interhemispheric coherences were attenuated especially in delta, theta, and beta bands, which were commonly observed in frontal to central areas. Conclusion Sex differences in resting EEG coherences were attenuated in schizophrenia patients. These results imply that sex-related aberrant cerebral lateralization might exist in patients with schizophrenia, which are partly due to sex hormones via epigenetic mechanisms.

• 한국작물학회지
• /
• 제53권spc호
• /
• pp.58-64
• /
• 2008

Cyanidin-3-glucoside(C3G) 고함유 흑자색미 계통을 육성하기 위해 흑진주, 수원425호, 상해향혈나, 용금1호, C3GHi 품종 및 계통들 간에 완전이면교배에서 얻은 20개 조합 $F_1$의 현미 천립중과 C3G함량에 대한 diallel analysis 및 조합 능력 분석 결과는 다음과 같다. 1. 교배모본의 현미 천립중은 16.6 g(흑진주) - 30.4 g(상해향혈나)이고, 현미 100 g당 C3G 함량은 C3GHi가 흑진주의 5배 정도 높은 1043.5 mg으로 나타났다. 2. 완전이면교배 결과 현미 천립중과 C3G 함량은 비대립 유전자 효과는 나타나지 않았고, 유전자의 상가적 및 우성적 유전효과만 인정되었다. 3. 현미 천립중과 C3G 함량의 유전 양식은 두 형질 모두 상가적 및 우성효과에 의한 부분우성을 보였으며, 평균 우성정도는 각각 0.80 및 0.69였고, 교배모본에서 정의대립 유전자 비율이 높았으며, 우성친의 빈도가 높고, 후대에서는 감소하는 방향으로 작용하였다. 4. 두형질의 상가적 유전효과에 의한 협의의 유전력은 각 각 0.66, 0.70이고, 광의의 유전력은 각각 0.98, 0.98로 높게 나타났다. 5. 현미 천립중에 대한 일반조합능력 효과는 상해향혈나가 가장 높았고, 흑진주가 가장 낮았으며, 흑진주/수원425 호, 수원425호/C3GHi 조합의 특정조합능력 효과가 가장 높았다. 6. C3G함량에 대한 일반조합능력 효과는 C3GHi가 가장 높았고, 상해향혈나가 가장 낮았으며, 흑진주/C3GHi 조합에서 특정조합능력 효과가 가장 낮게 나타났다.

• Annals of Clinical Neurophysiology
• /
• 제10권2호
• /
• pp.104-108
• /
• 2008

Background: The compression of 7th cranial nerve by arteries is one of the various causes of hemifacial spasm (HFS). A few previous studies were revealed the relation between the compression of 7th cranial nerve and common trunk anomaly. We evaluated the common trunk anomalies in patients with HFS using MRI and MRA. Methods: From January 2001 to December 2005, 41 consecutive patients (9 men, mean age $54.5{\pm}12.6$) with HFS underwent MRI and MRA. T2 axial images and time-of-flight angiographies were reviewed for identification of the compression at root exit zone by two neuroradiologists and one neurologist. Results: Thirty-seven patients showed neurovascular compression on the lesion side. Twenty patients of them were shown the compression of 7th cranial nerve by anterior inferior cerebellar artery (AICA), and seventeen patients of them were shown the compression by posterior inferior cerebellar artery (PICA). Twenty-four patients of the thirty-seven patients had common trunk anomaly. In control, twelve of twenty-one subjects had common trunk anomaly, that the frequencies of common trunk anomaly of two groups were 58.8% in HFS and 57.1% in controls. In the twenty-four patients with common trunk anomaly, eighteen patients had dominant-AICA, and six patients had dominant-PICA. The rate of nerve compression by common trunk anomaly in the HFS with unilateral common trunk, dominant-AICA was 76.5% and dominant-PICA was 100%. Conclusions: This study also revealed that AICA was most common compressive artery. There was no difference between the HFS groups and control groups in frequency of common trunk anomaly. Thus, we could not demonstrate the relationship between common trunk anomaly and HFS.