• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.427-430
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• 1990

Cholesteryl aniline ($C_{33}H_{51}N$) is monoclinic, space group $P2_1$, with a = 9.020(3), b = 6.000(1), c = 27.130(9)${\AA},\;{\beta} = 98.22(2)^{\circ}$, Z = 2, Dc = 1.06 g/cm$^3$ and Dm = 1.04 g/cm$^3$. A diffraction data set was collected with Mo-$K_{\alpha}$ radiation (${\lambda} = 0.7107 {\AA}$) on a diffractometer with a graphite monochromator to a maximum 2${\theta}$ value of 50$^{\circ}$, by the ${\omega}-2{\theta}$ scan technique. The coordinates of the non-hydrogen atoms and their anisotropic temperature factors were refined by full-matrix least-squares methods to final R of 0.058. In cholesteryl group, bond distances were normal except in tail part, where high thermal vibration resulted in apparent shortening of the C-C distances. The crystal structure consists of bilayers of thickness $d_{001} = 27.13 {\AA}$, in each of which there is the tail to tail arrangement of molecules aligned in the unit cell with their long axes approximately parallel to the [104] axis. The two halves of the double layer are related to each other by the screw axis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권3호
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• pp.591-609
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• 2024

In this study, preprocessings with all combinations were examined in terms of the effects on decreasing word number, shortening the duration of the process and the classification success in balanced and imbalanced datasets which were unbalanced in different ratios. The decreases in the word number and the processing time provided by preprocessings were interrelated. It was seen that more successful classifications were made with Turkish datasets and English datasets were affected more from the situation of whether the dataset is balanced or not. It was found out that the incorrect classifications, which are in the classes having few documents in highly imbalanced datasets, were made by assigning to the class close to the related class in terms of topic in Turkish datasets and to the class which have many documents in English datasets. In terms of average scores, the highest classification was obtained in Turkish datasets as follows: with not applying lowercase, applying stemming and removing stop words, and in English datasets as follows: with applying lowercase and stemming, removing stop words. Applying stemming was the most important preprocessing method which increases the success in Turkish datasets, whereas removing stop words in English datasets. The maximum scores revealed that feature selection, feature size and classifier are more effective than preprocessing in classification success. It was concluded that preprocessing is necessary for text classification because it shortens the processing time and can achieve high classification success, a preprocessing method does not have the same effect in all languages, and different preprocessing methods are more successful for different languages.

• 한국임상수의학회지
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• 제36권3호
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• pp.159-165
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• 2019

Pimobendan is an inodilator used to treat canine heart failure, and pentoxifylline is reported to be beneficial for microcirculation and heart disease. The purpose of this study was to evaluate the pharmacokinetic and pharmacodynamic profiles of a novel pimobendan-pentoxifylline liquid mixture after oral administration to dogs. Eight healthy Beagle dogs were included in the study. The dogs were divided into the control group (orally administered water; n = 4) and experimental group (orally administered pimobendan-pentoxifylline liquid mixture [pimobendan 0.25 mg/kg, pentoxifylline 15 mg/kg]; n = 4). Plasma samples were obtained and echocardiographic indices were measured for 24 hours after administration. The concentrations of pimobendan and pentoxifylline were quantified by using a liquid chromatography-mass spectrometer (LC-MS). The elimination half-life ($T_{1/2}$) was $32.96{\pm}9.80mins$ for pimobendan and $29.49{\pm}6.67mins$ for pentoxifylline. The time to reach maximum concentration ($T_{max}$) were $52.50{\pm}31.22mins$ for pimobendan and $41.25{\pm}18.87mins$ for pentoxifylline. The maximum blood concentration ($C_{max}$) was $96.92{\pm}75.64ng/mL$ for pimobendan and $7074.07{\pm}3261.1ng/mL$ for pentoxifylline. Of the echocardiographic indices, fractional shortening (FS) and left ventricular internal diameter at end systole (LVIDs) were significantly altered at 1-3 hours after the administration of pimobendan-pentoxifylline liquid mixture. The pimobendan-pentoxifylline liquid mixture was well tolerated by the dogs, with no adverse effects observed during the study.

• 대한핵의학회지
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• 제17권2호
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• pp.1-17
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• 1983

The purpose of this study is to investigate the effects of thyroid hormone on the left ventricular(LV) volume arid function in man with untreated hyperthyroidism and to determine the effects of successful therapy for thyrotoxicosis on the ventricular pathophysiology. In the present study, equilibrium radionuclide cardiac angiography was performed and LV volume index, ejection phase indexes of LV performance, serum thyroid hormone levels and other hemodynamic parameters were measured in 28 normal subjects and 39 patients with hyperthyroidism before treatment and again every 4 weeks for the first 2 months after the initiation of effective therapy. The results obtained were as follows; 1) In the untreated hyperthyroid state heart rate, blood volume, cardiac index and stroke volume index($97{\pm}14$ beats/min, $73.5{\pm}11.8ml/kg,\;6.9{\pm}1.4\;l/min/m^2$ and $77.6{\pm}13.8ml/m^2$, respectively) were increased significantly compared to those in normal control($74{\pm}12beats/min$, $66.6{\pm}14.8ml/kg,\;3.8{\pm}1.2\;l/min/m^2$ and $56.6{\pm}13.2ml/m^2$ respectively). $(Mean{\pm}SD)$ 2) There was a significant increase in LV end-diastolic volume index in patients with hyperthyroidism ($30.5{\pm}7.5$ for hyperthyroid group compared to a normal control of $22.2{\pm}6.5$; p<0.001), whereas end-systolic volume index remained unchanged $9.6{\pm}3.6\;and\;8.8{\pm}3.3$ respectively).3) In patients with hyperthyroidism, LV ejection fraction was $70.0{\pm}5.6%$, fractional shortening $32.9{\pm}5.1%$, mean velocity of circumferential fiber shortening(mean Vcf) $1.34{\pm}0.31$ circ/sec and maximum ejection rate $3.47{\pm}0.80$. All the ejection phase indexes were significantly greater than those in normal control($65.2{\pm}5.7%,\;28.8{\pm}3.2%,\;0.88{\pm}0.37$ circ/see and $2.27{\pm}0.50$, respectively; p<0.001). 4) Effective therapy produced significant decrease in all the values of serum thyroid hormone concentrations(p<0.00l), hemodynamic parameters(p<0.001), end-diastolic volume index(p<0.01) and ejection phase indexes of LV contractility in patients with hyperthyroidism and after one to two months, when the patients were euthyroid, these measurements were in the range of normal. 5) A significant linear correlation between mean Vcf and serum thyroxine level(r=0.63, p<0.001) as well as between mean Vcf and serum triiodothyronine level(r=0.62, p<0.001) was found. The lesser degree of correlation was also noted between other ejection phase indexes and serum thyroid hormone concentrations. The results indicate that the major effects of excess thyroid hormone on the LV in human beings with hyperthyroidism are an enhancement of LV function and an increase in LV enddiastolic volume and that these effects cause predictable reversible cardiac alteration which are changed dramatically and immediately after effective therapy.

• 한국응용곤충학회지
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• 제18권3호
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• pp.127-132
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• 1979

본 실험은 몇가지 우화기구를 사용하여 기구형에 따른 우화상내 온도변화가 솔잎혹파리의 우화소장에 미치는 영향 및 유충의 월동기간중의 온도변화와 우화소장간의 관계를 알아 보기 위하여 각처리별 우화소장을 조사하여 다음과 같은 결과를 얻었다. 1) 우화기구별 상내 최고온도는 현저한 차리를 나타내어 대조구에 비하여 Vinyl형은 월평균 $15^{\circ}C$가 높았고 다른 처리구에 있어서도 $30^{\circ}C\~12^{\circ}C$가 높았는데 다른 처리구에 있어서도 $30^{\circ}C\~12^{\circ}C$가 높았는데 표준형의 순이었다. 2) 처리별유충의 월동기간중의 최저온도분포는 현저한 차이를 나타내지 않았다. 3) Vinyl형 처리구에서는 우화최성일이 5월 15로 대조구에 비하여 20일 앞당겨했고 표준형구와 Cage-50구도 14일 빨라졌다. 4) Funnel형 처리구에 있어서는 최고온도 및 적산온도의 분포가 대조구에 비하여 높았음에도 불구하고 우화최성일은 6일이 지연되었다. 5) 유충의 월동기간중의 온도처리효과는 12월중순과 3월중순의 최고온도의 상승이 우화최성일을 앞당기는 효과를 나타내었다.

• 한국산학기술학회논문지
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• 제22권4호
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• pp.160-166
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• 2021

본 연구에서는 화재, 붕괴, 특수사고, 산불 등의 4개의 재난·재해 중 화재현장에서 활용 가능한 재난안전로봇의 교육적 활용을 위한 시나리오를 개발하고 이 시나리오를 바탕으로 로봇 활용 교육에 따른 효과분석을 목표로 한다. 시나리오는 현직 소방대원을 대상으로 설문지 조사를 통해 방향성, 현실성 및 합리성 내용을 중심으로 시나리오를 개발하였다. 또한 재난안전로봇의 활용 교육 및 훈련의 효과를 확인하기 위해 로봇 개발연구진, 현직소방대원, 대학생들을 대상으로 반복적인 로봇 조종 훈련을 통하여 분석하였다. 로봇조종은 직접조정, 모니터조종, 시뮬레이터조종으로 구분하여 테스트를 5회 실시하여 하였다. 로봇조정 테스트분석결과 각 그룹별로 소요된 평균시간은 대학생이 28초로 가장 빨랐으며 연구개발팀(30초), 소방대원(38초) 순으로 나타났다. 개인별 분석결과를 보면 직접조정의 경우에는 소방대원이 (최대 35초), 모니터 조정에는 연구개발팀이 (최대 14초), 시뮬레이터 조종에서는 소방대원 (최대 22초)의 조종시간 단축의 효과를 나타냈다. 이는 재난·재해 현장에서 로봇을 보다 효과적으로 활용하기 위해서는 반복적인 로봇 조종 교육 및 훈련이 필요함을 입증했다.

• 한국철도학회논문집
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• 제16권5호
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• pp.402-409
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• 2013

현재 운영되고 있는 광역도시철도 시스템에서는 표정속도의 저하에 따라 평균 출퇴근 시간도 계속 증가하고 있으며 이는 도시철도 이용률의 저하와 타 교통수단 대비 졍쟁력 저하로 이어지게 된다. 따라서 열차의 표정속도를 대폭 향상시킬 수 있는 광역도시철도의 효율적인 급행화 방안이 요구되고 있다. 이번 연구에서는 가감속도와 최고속도 성능을 향상시킨 고성능 전동차 투입을 고려하여 급행과 완행으로 분리 투입시 획득 할 수 있는 시간 단축 효과와 경제성을 기준으로, 광역철도간 급행화 방안들을 제안 및 그 결과를 비교 분석하였다. 또한 대피선 설치를 최소화 할 수 있는 최적의 급행화 방안을 분석결과로 제안하였다.

• Journal of Positioning, Navigation, and Timing
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• 제5권4호
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• pp.193-202
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• 2016

The Korea Augmentation Satellite System (KASS), which is under development in Korea as a Satellite Based Augmentation System (SBAS) is expected to broadcast SBAS messages to air space in Korea according to the international standards defined by the International Civil Aviation Organization (ICAO) and the Radio Technical Commission for Aeronautics (RTCA). Around 13 SBAS messages are broadcast in every second to transmit augmentation information which can be applicable to a wide area in common. Each of the messages requires a different update interval and time-out according to the characteristics, purpose, and importance of transmitted information, and users should receive and combine multiple SBAS messages to calculate SBAS augmented information. Thus, a time to take acquiring first SBAS position by users differs depending on broadcasting various SBAS messages with which order and intervals. The present paper analyzes the considerations on message scheduling for broadcasting of KASS augmentation information and proposes a design of KASS message scheduler using the considerations. Compared to existing SBAS systems, which have a wide range of service area, a service area of the KASS is limited to Korea only. Thus, the numbers of ionosphere grid points and satellites to be augmented are expected to be smaller than those of existing SBAS. By reflecting this characteristic to the proposed design, shortening of broadcast interval of KASS message is verified compared to existing SBAS and a measure to increase a speed of acquisition of user navigation solution is proposed utilizing remaining message slots. The simulation result according to the proposed measure showed that the maximum broadcast interval can be reduced by up to 20% compared to that of existing SBAS, and users can acquire KASS position solution faster than existing SBAS.

• 대한기계학회논문집A
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• 제21권8호
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• pp.1250-1258
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• 1997

This paper reports on the development of a new foot for a quadrupedal jointed-leg type walking robot. The foot has 2 toes, one at the front and the other at the rear side, for stable landing on uneven ground by point contact. The toes can move up and down independantly, guided by double-wishbone shaped parallel links which enable the lower leg to rotate with respect to a remote center on the ground surface. The motion of each toe is damped by a hydropneumatic shock absorber integrated in the foot in order to absorb the dynamic landing shock. Furthermore, the new foot can reduce the maximum hip joint drive torque by shortening the moment arm length between the hip joint and the landing force vector on the ground. Intensive experiments were carried out in this study by using a one-leg walking model to investigate the soft landing performance of the foot which could be hardly offered by conventional robot feet such as a flat plate with a gimbal type ankle joint. And it was confirmed that the hip joint torque of the leg walking on the flat surface could be reduced remarkably by using the new foot.

• 대한약리학회지
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• 제12권1호
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• pp.45-55
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• 1976

The effect of positive inotropic agents on the contractile properties of myocardial muscle were studied in the cat papillary muscle preparation. For the purpose, the effects of ouabain $(1{\times}10^{-6}g/ml)$, norepinephrine (0.05r/m1) and Aconiti tuber butanol fraction (AF(5), $1{\times}10^{-4}$, $5{\times}10^{-4}$, $1{\times}10^{-3}$, $2{\times}10^{-3}g/ml$) on the contractile dynamics of the papillary muscle preparation isolated from right ventricle of cat were observed in terms of the characteristics of isometric twitch and the lengh-tension relation, the force-velocity relation and the load-extension relation of the series elastic component of contractile model of A.V. Hill. All the studied inotropic drugs similary increased the rate and the intensity of the developed isometric tension, while shortened the time from onset of contraction to peak tension and the total duration of contraction. In the afterloaded simultaneous isotonic and isometric contraction, they also similary increased the maximal velocity of shortening accompanied with the increasing the maximum developed force. In the load-extension relation all the drugs, however, had no appreciable influence on the properties of the series elastic component. Increasing the concentration, Aconiti tuber butanol fraction produced more pronounced effect on all the studied parameters of isometric and isotonic contraction of cat papillary muscle preparation. From the aspect of contractile dynamics, it seemed that the positive inotropic effect of ouabain, norepinephrine and Aconiti tuber butanol fraction are similary achieved through an influence on the behavior of the contractile component only.