• 제목/요약/키워드: met-frequency

검색결과 201건 처리시간 0.027초

카본블랙/섬유강화 복합재료의 전자파 차폐효과 (Electromagnetic Interference shielding effectiveness of carbon black / Glass fiber woven roving and Carbon fiber unidirectional fabric reinforced composite)

  • 김진석;한길영;안동규;이상훈;김민수
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1322-1325
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    • 2005
  • The main objectives of this research work are to develop conductive glass fiber woven roving and carbon fiber unidirectional fabric composite materials and to determine their electromagnetic shielding effectiveness(EMSE). Epoxy is the matrix phase and glass, carbon fiber are the reinforcement phase of the composite material. Carbon black are incorporated as conductive fillers to provide the electromagnetic shielding properties of the composite material. The amount of carbon black in the composite material is varied by changing the carbon black composition, woven roving and unidirectional (fabric) structure. The EMSE of various fabric composites is measured in the frequency range from 300MHz to 800MHz. The variations of EMSE of woven roving and unidirectional composites with fabric structure, metal powder composite are described. Suitability of conductive fabric composites for electromagnetic shielding applications is also discussed.

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전남지역 남해안 풍력자원조사 연구 (Analysis of Wind Resources of the South Seashore of JeonNam Province)

  • 김영찬;정진화;이응채;전중환;한경섭;김용환
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2006년도 추계학술대회
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    • pp.281-285
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    • 2006
  • As the needs of wind energy increase, the more sites for the wind farm are required. As a part of searching for the prominent wind farm site, specially for offshore wind farm, we chose 4 sites along the southern part seashore of JeonNam province based on the analysis of the data gathered by meteorological observatory ud have gathered wind data for more than a year by use of 40m Met masts installed in the representative locations, ie. small islands of 4 different bay area. The siting for the Met masts were very limited by the geographical circumstances The wind data of those areas show a little lower annual average wind speeds, for the wind farm development, of 4m/s to 5.5m/s at the height of 40m above the ground level of the respective islands. The detail figures of one year wind data of those area are presented in this report.

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사회적 지지의 특성에 따른 뇌졸중 환자의 우울 (The Relationship between the Characteristics of Social Support and Post-Stroke Depression)

  • 김인자;서문자;김금순;조남옥
    • 재활간호학회지
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    • 제2권2호
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    • pp.206-214
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    • 1999
  • The effect s of social support on post-stroke depression were investigated. Social support was classified into three categories : primary caregiver's, significant other's, and professional support. And primary caregiver's and significant other's support were divided into their relation, living state (which means they living together or not), frequency which they met at, and perceived satisfaction about the support, respectively. Professional support was divided into number of professionals who take care of, frequency they met at, and perceived satisfaction. The subjects were 254 stroke patients who had been discharged and were taken follow-up care at the out patient department. The depression was measured using CES-D. Out of the primary caregiver's support, only relation and perceived satisfaction were identified to affect the post-stroke depression. The patients who primarily their spouse takes care of were less depressed than those who their adult children take care of. None of the significant other's support affects the post-stroke depression. Only perceived satisfaction of the professional support was found to affect the post-stroke depression. So it was found that the quality, not the amount, of care was important to post-stroke depression. These results also support the claim that the facilities and teaching programs for primary caregivers are necessary.

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WCDMA(UMTS)용 다중출력 VC-TCXO (Multi-output VC-TCXO for WCDMA(UMTS))

  • 정찬용;이해영
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2005년도 추계종합학술대회
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    • pp.841-844
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    • 2005
  • Multi-output VC-TCXO (Voltage Controlled-Temperature Compensated Crystal Oscillator) for WCDMA has integrated the additional CMOS inverter, so it can be normal clipped sinewave output and additional CMOS output and it can be satisfied the VC-TCXO Characteristics that WCDMA system required. In this paper, however 26MHz is used for reference frequency, similarly and practically, it is usable from 10MHz to 40MHz, Most important factor to integrate CMOS inverter internally is the isolation between normal output and additional output. For this, it is separated in package design, due to this, when it isn't used additional output, it shows the same electrical performance, when it is used additional output, it has minimum-rized the interference. and then the important characteristics in reference oscillator are met to WCDMA system's requirements, like phase noise and frequency short term stability.

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기저막 특성을 이용한 새로운 음성 특징 추출 및 성능 분석 (Performance of analysis and extraction of speech feature using characteristics of basilar membrane)

  • 이철희;신유식;정성환;김종교
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2000년도 제13회 신호처리 합동 학술대회 논문집
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    • pp.153-156
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    • 2000
  • 본 논문에서는 음성 인식률 향상을 위한 여러 가지방법들 중에서 음성특징 파라미터 추출 방법에 관한 한가지 방법을 제시하였다. 본 논문에서는 청각 특성을 기반으로 한 MFCC(met frequency cepstrum coef-ficients)와 성능 향상을 위한 방법으로 GFCC (gamma-tone filter frequency cepstrum coefficients)를 제시하고 음성 인식을 수행하여 성능을 분석하였다. MFCC에서 일반적으로 사용하는 임계 대역 필터로 삼각 필터(triangular filter) 대신 청각 구조의 기저막(basilar membrane)특성을 묘사한 gammatone 대역 통과 필터를 이용하여 특징 파라미터를 추출하였다. DTW 알고리즘으로 인식률을 분석한 결과 삼각 대역 필터를 이용한 것보다 gammatone 대역 통과 필터를 이용한 추출법이 약 2∼3%의 성능 향상을 보였다.

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부분 손상된 음성의 인식성능 향상을 위한 가중 필터뱅크 분석 및 모델 적응 (Weighted filter bank analysis and model adaptation for improving the recognition performance of partially corrupted speech)

  • 조훈영;오영환
    • 대한음성학회지:말소리
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    • 제44호
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    • pp.157-169
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    • 2002
  • We propose a weighted filter bank analysis and model adaptation (WFBA-MA) scheme to improve the utilization of uncorrupted or less severely corrupted frequency regions for robust speech recognition. A weighted met frequency cepstral coefficient is obtained by weighting log filter bank energies with reliability coefficients and hidden Markov models are also modified to reflect the local reliabilities. Experimental results on TIDIGITS database corrupted by band-limited noises and car noise indicated that the proposed WFBA-MA scheme utilizes the uncorrupted speech information well, significantly improving recognition performance in comparison to multi-band speech recognition systems.

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교류가 유도되는 매설배관에서의 교류 부식속도 측정에 관한 연구 (Corrosion Rate of Buried Pipeline by Induced Alternating Current)

  • 송홍석;김영근;이성민;고영태;박용수
    • 한국가스학회:학술대회논문집
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    • 한국가스학회 2001년도 추계학술발표회 논문집
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    • pp.45-57
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    • 2001
  • An alternating current (AC) corrosion using coupon has been studied. Coupons were applied in terms of AC voltage from high value to low value through the survey of AC voltages on buried gas transmission pipeline over the country. Parameters such as AC current density of coupon, AC voltage, cathodic protection potential, soil resistivity and frequency were monitored continually. Corrosion induced by AC was observed even under cathodically protected condition that met cathodic protection criterion(: below -850mv vs. CSE). Corrosion rate was affected mainly not by AC voltage but by both of frequency and AC current density. An experimental corrosion rate relationship could be obtained statistically, in which AC corrosion rate increased linearly with effective AC current density and its slope was 0.619.

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Corrosion Rate of Buried Pipeline by Alternating Current

  • Song, H.S.;Kim, Y.G.;Lee, S.M.;Kho, Y.T.;Park, Y.S.
    • Corrosion Science and Technology
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    • 제4권1호
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    • pp.1-7
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    • 2005
  • An alternating current (AC) corrosion on buried pipeline has been studied using coupon and ER probe. Coupons and ER probes were applied to the sites from high value of AC voltage to low value based on the survey of AC voltages on buried gas transmission pipeline over the country. Parameters such as AC current density of coupon, AC voltage, cathodic protection potential, soil resistivity and frequency were monitored continually. Corrosion induced by AC was observed even under cathodically protected condition that met cathodic protection criterion (; below -850 mV vs. CSE). Corrosion rate was affected mainly not by AC voltage but by both of frequency and AC current density. An experimental corrosion rate relation could be obtained according to effective AC current density, in which AC corrosion rate increased linearly with effective AC current density, and its slope was 0.619 in coupon method and 0.885 in ER probes.

전분분해활성과 알코올 발효능을 보유한 효모의 육종 (Breeding of Yeast Strain with Starch Utilizing and Alcohol Fermenting Ability by Protoplast Fusion)

  • 주민노;홍성욱;김관태;염성관;김계원;정건섭
    • 한국미생물·생명공학회지
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    • 제36권2호
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    • pp.158-164
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    • 2008
  • Saccharomyces diastaticus KCTC 1804 균주와 Saccharomyces cerevisiae KOY-1 균주를 이용하여 전분분해활성과 알코올 발효능을 동시에 가지는 효모융합체를 개발하였다. Saccharomyces cerevisiae KOY-1 균주의 단수체 유도를 통하여 Saccharomyces cerevisiae KH-12 균주를 획득하였다. EMS를 사용한 돌연변이 유발을 통하여 Saccharomyces cerevisiae KH-12 균주의 Met 영양요구성 변이주를 획득하였다. Lyticase 처리로 Saccharomyces cerevisiae KOY-1 $(Met^-)$, Saccharomyces diastaticus KCTC 1804$(Trp^-)$ 균주의 원형질체 형성률은 각각 90.5%, 97.7%로 관찰되었다. 원형질체 융합은 polyethylene glycol 4,000을 이용하여 실시하였고, 이때 원형질체 융합율은 $1.79{\times}10^{-4}$으로 관찰되었다. 원형질체융합과정을 통해 총 1,000주의 융합체를 획득하였고, 획득한 융합체의 전분분해능과 알코올발효능을 비교하여 최종적으로 전분배지 YPS24에서 알코올생성능이 가장 우수한 효모융합체인 FA 776을 최종 선발하였다 최종 선발된 효모융합체 FA 776은 10세대 계대배양 후의 revertent 복귀율이 4.64%로 유전적 안정성을 확인하였으며, 효모융합체의 total DNA 함량을 비교한 결과, Saccharomyces cerevisiae 균주로부터 분리된 단수체 효모 KH-12는 26.56 fg/cell, Saccharomyces diastaticus KCTC 1804 균주는 25.40 fg/cell이었고, 이들을 사용해서 얻어진 융합체 FA 776의 DNA함량은 42.67 fg/cell이었다. 전분배지 YPS24배지에서 60시간 발효하였을때 Saccharomyces cerevisiae KOY-1 균주는 알코올 생성하지 못하였지만 효모융합체 FA 776은 13 mg/mL의 알코올을 생성하였다. 이는 전분이용성 효모인 Saccharomyces diastaticus KCTC 1804 균주에 비해 1.86배나 향상된 알코올 발효능을 나타냈다.

초등학교 아동의 비만지수와 신체활동에 관한 조사연구 (A Study on the Obesity Index and the Physical Activities of Elementary School Children)

  • 신재신;김명희;박형숙;송미경
    • 한국학교보건학회지
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    • 제13권1호
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    • pp.97-108
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    • 2000
  • This study researches an obesity index and the realities of physical activity of elementary school children and provide basic data to instruct correct physical activity for low weight and obese children. The subject was 813 Elementary School Children of grade 4-6 in Kyungju and data were collected with a Physical Activity Questionnaire from YHS, USA. The collected data were analyzed with real number, percentage, average and standard deviation techniques. The range was by SPSS WIN. Both of them were in the normal range, between -38.3 and 77.7, between low weight and obesity. The results are as follows : 1. An Obesity index according to grade and sex: the average obesity index of 423 boys was $7.56{\pm}15.7$, for girls it was $2.56{\pm}14.3$. Both of them were in the normal range, between -38.3 and 77.7. There were low weight($-38.85{\pm}0.9$) students as well as obese, including extremely low weight children ($-38.85{\pm}0.9$) and extremely obese children. 2. On the whole, in the Frequency of the 25 item physical activities breakdown, children reported to watch TV 1. ($2.7{\pm}0.6$), or do homework($2.1{\pm}0.9$), more than three-fourths of the week, male children, however, played more football($2.0{\pm}0.9$). As male obese children do less MET5, MET8(highly active activity) than male normal children, it was also discovered that low weight children do more severe activity in MET8(high activity). In female cases, it was revealed that neither do highly intense activity. 3. In physical activity, male children received higher points than female children with $92.94{\pm}37.95$ to $74.46{\pm}29.50$. On the whole, male and female obese children had lower score than normal children. 4. As for attitude toward physical activity, male children($31.96{\pm}4.37$) had a positive attitude than female children ($29.57{\pm}3.89$), but obese male children had a negative attitude regarding activity viewed as normal. Therefore, in preventing obesity in elementary school children the treating of under-weight children should be included in the obesity program so as to prevent mal-nutrition or deficiency. It is needed to instruct obese children to carry out intensive work-outs at least 3 times a week through systematic programs. It is also needed that parents and teachers educate elementary school children from an early age with information on the frequency and intensity of work-outs to prevent obesity. It is also desirable that children be educated to carry out physical activities that address their specific needs. As a result of this study, obesity management must be started from elementary school and children should be instructed to act in high-intensity actirities when they spend leisure time.

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