• Geomechanics and Engineering
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• 제34권2호
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• pp.197-208
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• 2023

Rate-dependent mechanical response of sand, subjected to loading of medium to high strain rate range, is of interest for several civilian and military applications. Such rate-dependent response can vary significantly based on the initial density state of the sand, applied confining pressure, considered strain rate range, drainage condition and sand morphology. A numerical study has been carried out employing a recently proposed visco-plastic constitutive model to explore the rate-dependent mechanical behaviour of Toyoura sand under drained triaxial loading condition. The model parameters have been calibrated using the experimental data on Toyoura sand available in published literature. Under strain rates higher than a reference strain rate, the simulation results are found to be in good agreement with the experimentally observed characteristic shearing behaviour of sand, which includes increased shear strength, pronounced post-peak softening and suppressed compression. The rate-dependent response, subjected to intermediate strain rate range, has further been assessed in terms of enhancement of peak shear strength and peak friction angle over varying initial density and confining pressure. The simulation results indicate that the rate-induced strength increase is highest for the dense state and such strength enhancements remain nearly independent of the applied confinement level.

• 말소리와 음성과학
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• 제8권3호
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• pp.61-66
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• 2016

The purpose of this study is to examine the speaking rate(overall speaking rate and articulatory rate) of Parkinson's disease patients with palilalia(PDP). Palilalia is traditionally characterized by not only compulsive repetitions of words and phrases, but also by increased rate of speech based on auditory perception. Since Souques(1908) first characterized palilalia as fast speech rate from the perspective of auditory perception, few studies have evaluated PDP speech using acoustic methods. To compare the speech rate between PDP and normal subjects, we included five PDP and eight control subjects(age over 55), as well as the date acquired under reading tasks(standardized Korean paragraph). The difference in median of the overall speaking rate was not statically significant between the PDP group(median 5.25, IQR 1.30) and normal group(median 4.76, IQR 0.71). The PDP, however, had a significantly higher syllables per second on the articulatory rate(median 6.60, IQR 1.04) than normal subjects(median 5.60, IQR 0.52). Results indicated no differences in pause over 250msec and disfluency duration between the two groups. To provide useful insight into PDP speech, multiple levels of analysis should be employed.

• Communications for Statistical Applications and Methods
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• 제6권2호
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• pp.383-395
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• 1999

This study is concerned with the evaluation of predictive ability of classification models with ordered multiple categories. If categories can be ordered or ranked the spread of misclassification should be considered to evaluate the performance of the classification models using loss rate since the apparent error rate can not measure the spread of misclassification. Since loss rate is known to underestimate the true loss rate the bootstrap method were used to estimate the true loss rate. thus this study suggests the method to evaluate the predictive power of the classification models using loss rate and the bootstrap estimate of the true loss rate.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 가을 학술발표회 논문집
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• pp.215-222
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• 1997

Flow experimental on not to be solid mortar which use Quenched Blast-furnace Slag as a fine aggregate was carried out for basic research data about fundamental study of application possibility of Quenched Blast-furnace Slag as a fine aggregate. It gives following result. The substitution rate is inversely proportional to Flow and C/S-rate same that. The relation with W/C-rate augment appear proportional : in case of C/S-rate, 1:3 increasing degree is a half of sand mortar that. Consequencely, Quenched Blast-furnace Slag motar is a counteraction to Flow in as same water content per unit. But suitable substitution rate and C/S-rate influence a little to the mortar consistency. And that reason, if C/S-rate and substitution rate will be regulated when we mix the mortar with quenched Blast-furnace Slag. that will be economic mixture.

• Clinical and Experimental Reproductive Medicine
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• 제21권2호
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• pp.221-226
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• 1994

Copper T 380A intrauterine devices were inserted to nine thousand and nine hundred twenty women by 51 KAVS-member physicians since January 1, 1993 through December 31, 1993. This study was undertaken for the clinical analysis on a total of 9,920 women wearing Copper T 380A to grasp the effectivness as well as the expulsion rate due to a various side effects. The following features were the results of the study: 1. During the twelve months period, from January 1993 to December 1993, the largest number of IUD insertion per one physician is 740 cases and the smallest number 60 cases, the mean 195 cases. 2. After insertion of Copper T 380A, a total of 117 cases were removed the IUD;81 cases(0.8%) were due to extensive bleeding and 36 cases(O.36%) were due to pain. The pregnancy failure rate represented comparatively lower rate, 0.08% (8 cases) and the expulsion rate was 0.06%(6 cases). 3. The removal rate of Copper T 380A was different by physicians. The highest removal rate for bleeding was 3.13% and 13 physicians(25.5%) did not experience any bleeding cases. 4. For the removal rate for pain, 30 physicians(58.8%) did not experience any removal of IUD due to pain while 21 physicians(41.2%) removed IUD due to pain: 17 physiciansC33.4 %) had 0.1-1.5% of removal rate and 4 physiciansC7.0%) had 1.6-2.1% of removal rate. 5. A total of 43 physicians(84.3 %) did not experience any pregnancy failure case while 8 (15.7%) physicians was experienced pregnancy failure rate. Four physicians(7.8%) had 0.1-0.5% of pregnancy failure rate and 4 physicians had 0.6-1.0% of pregnancy failure rate. 6. Expulsion rate showed comparatively lower, 0.06% in this study. A total of 45 physicians (88.2%) did not experience any expulsion cases while 6 physicians(11.7%) had expulsion rate with the highest expulsion rate of 2.0%.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.937-940
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• 1992

A cost-saving feeding rate contro method for a batch reaction process is proposed by reconfigurating the flow rate control loop where the feeding rate is estimated by differentiating weight measurement. While the existing control methods require either a flow rate measurement device or a flow rate estimator, the proposed method is devised not to require neither of these facilities by directly controlling the tank weight with a time-varying set point. Experimental evaluation in a pilot-scale unit shows that the proposed method can significantly reduce the actuator hunting of the existing method where the flow rate is estimated by differentiating the weight measurement.

• 산업경영시스템학회지
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• 제15권26호
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• pp.159-163
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• 1992

The assumption of reinvestment rate leads to the results conflicting with the priority order of investments determined by net present worth. It has been revealed through various studies that the priority order of projects determined by the criteria based on internal rate of return is different from that determined by present worth. This study is to find out how to define reinvestment rate of return influencing the decision-making of the priority order through examining the meanings of reinvestment rate of capital and true rate of return, and to present some examples with a simple mathematical model.

• 전기전자학회논문지
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• 제2권2호
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• pp.233-238
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• 1998

본 논문에서는 G.726 ADPCM 음성방식을 기존의 단일 압축을 대신 16Kbps 와 40Kbps의 두 가지 압축율을 사용한 가변 압축방식에 의한 음성 코딩 방식을 다루었다. 음성의 묵음 또는 소 신호 부분은 음질의 향상보다는 데이터 비트 수를 줄이기 위한 저 전송 16Kbps 압축율을 적용하였고 임계값 이상의 대 신호 부분은 음질을 향상하기 위하여 40Kbps의 압축율을 적용하여 모든 신호를 단일 압축율로 코팅하는 방식에 비하여 전체적으로 압축율을 높여 전송 비트 수를 줄이면서 음질을 저하시키지 않도록 하였다. 분 논문에서는 시뮬레이션을 통하여 여러 가지의 임계값에 의한 가변 압축 코딩 방식에 대하여 압축율과 음질의 관계 를 다루었다. 또한 고정된 임계값에 대하여 입력 음성의 크기를 여러 가지로 변동하여 주변 배경잡음과 포화에 의한 음질의 저하를 고찰하여 가변 율에 의한 음성의 코딩방식에서 임계값과 입력의 크기가 음질 및 압축율에 미치는 영향을 다루었다. 각 시뮬레이션의 경우에 대하여 실지 음성의 원음에 대한 음질의 충실 도를 임의의 집단에 대하여 비교하여 음질의 충실 도를 확인하였다. 추후의 연구를 통하여 DSP에 의한 실시간 처리 시스템의 구현을 하고자 한다.

• 국제지역연구
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• 제21권1호
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• pp.181-200
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• 2017

본 논문에서는 2006년 초부터 2015년 말까지 우리나라의 산업별 주가지수와 주요화폐의 환율을 이용하여 환율과 환율 변동성이 주가에 미치는 영향을 분석하였다. 주가지수로는 코스피지수와 우리나라의 대표적 산업인 음식료품, 화학, 기계, 전기전자, 종이목재, 전기가스, 운수장비, 은행 주가지수가 사용되었으며 환율의 변화를 보기 위한 주요화폐로서는 미국달러, 일본 엔, 유로, 영국 파운드가 사용되었다. 환율변화에 따른 주가의 반응분석에서는 예상한 바와 같이 전자, 운수장비 산업 주가와 환율은 정(+)의 관계를 나타내었으며 음식료품, 종이목재, 전기가스, 은행 산업의 경우도 예상한 것과 같이 주가와 환율은 부(-)의 관계를 나타냈다. 수출의 비중이 많은 기계 산업은 예상과 달리 부(-)의 반응을 보이는 것으로 나타났다. 화학 산업의 경우는 예상이 어려웠는데 분석결과 주가와 환율은 부(-)의 관계를 보여 주었다. 환율변동성에 대한 주가의 반응 분석에서는 종이목재 산업의 주가가 환율변동성에 부(-)의 반응을 나타냈다. 환율변동성에 대비한 위험관리 비용을 많이 지출하는 기업들이 종이목재산업에 속해 있는 것으로 보인다. 또한 은행산업의 주가도 환율변동성에 부(-)의 반응을 보였는데 이것은 선도환 등 외환 파생상품을 발행하여 수수료 수입이 증가하게 되는 은행산업의 주가는 환율변동성에 정(+)의 반응을 할 것이라는 예상과는 정반대의 결과였다.

• 지역연구
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• 제11권2호
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• pp.41-51
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• 1995

It has been estimated the total factor productivity(TFP)of the city of Seoul. Average TFP growth rate during 1974-1992 has been estimated as 0.0602. TFP growth rate has been decreased from 0.0804 of 1970's to 0.0561 of 1980 and 1990's Factsro affecting the TFP are found to be core infrastructure, capital stock and land price growth rate. High land price growth rate depresses the TFP growth rate. During 1989, due to the high land price growth rate and extremely low building costruction permit TFP rate has been estimated as negative.