• The Korean Journal of Physiology
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• 제22권2호
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• pp.207-218
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• 1988

Effects of 1, 4-dihydropyridine compounds, such as nifedipine, nisoldipine, nitrendipine, and nimodipine which were calcium antagonists on the normal and Ca-dependent, slow channel mediated action potentials in the guinea pig's papillary muscle were investigated. The glass microelectrode was impaled into a papillary muscle cell for measurements of potential changes with the simultaneous tracing of isometric contraction. The concentration of Ca antagonists were 1 mg/l (nifedipine and nisoldipine), 2 mg/l (nitrendipine and nimodipine), which showed the maximal inhibition of isometric contraction (above 90%) and simultaneous effects on the normal action potentials and only the halves of those concentrations were sufficient to observe the effects on the calcium action potentials. The data for analysis were only chosen when the microelectrode was maintained in a cell throughout the experiments. 1, 4-Dihydropyridine compounds decreased the action potential duration but did not affect the resting membrane potential, overshoot, and upstroke velocity of the normal action potentials with the decrease in the isometric contraction. And with the decrease in the area and amplitude of isometric contraction, the area, amplitude, upstroke velocity and duration of Ca action potential was decreased. But the differences in the effects of the Ca antagonists were not observed. Therefore it is inferred that the changes in normal and Ca action potential induced by the 1, 4-dihydropyridine compounds with a common chemical structure would be caused by the slow inward Ca-current, not by a fast Na-current.

• 약학회지
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• 제32권4호
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• pp.258-273
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• 1988

In this study attempts were made to observe the effects of guanabenz on renal function in dog, which manifests the antihypertensive action by inhibition of sympathetic tone through stimulating the presynaptic adrenoceptor (${\alpha}_2-adrenoceptor$). Guanabenz, when injected at a dose of $30.0{\mu}g/kg$, or infused at a dose of $3.0{\mu}g/kg/min$ intravenously, produced diuretic action with increased amounts of $Na^+\;and\;K^+$ in urine, and with decreased reabsorption rates of $Na^+\;and\;K^+$ in renal tubules. It was also observed that the rates of osmolar and free water clearances were increased, but the glomerular filtration rate and renal plasma flow were not changed. Guanabenz injected at a dose of $3.0{\mu}g/kg$ into a carotid artery or infused intravenously at a dose of $3.0{\mu}g/kg/min$ in a state of water diuresis elicited the diuretic action of the similar aspect as a case of guanabenz given intravenously. The diuretic action produced by guanabenz was completly blocked by pretreatment of i.v. prazosin, ${\alpha}_1-adrenoblocking$ agent, or of i.v. yohimbine, ${\alpha}_2-adrenergic$ blocking agent. Prazosin, when given into a renal artery, inhibited the diuretic action by i.v. guanabenz in only injected kidney, whereas in case of yohimbine the action was inhibited in both kidney. Guanabenz infused at a dose of $1.0{\mu}g/kg/min$ into a renal artery exhibited no significant changes of renal function in both kidney. In denervation experiments, guanabenz given intravenously produced typical diuretic action in innervated kidney, whereas in denervated kidney, it did not affect the action at initial period but exhibited the action with increase of only free water clearance at later period. These results suggest that guanabenz produced diuretic action in dog by inhibition of electrolyte reabsorption rates in renal tabules, mainly proximal tubule and of ADH release, which is mediated by stimulating of central sympathetic ${\alpha}_2-receptor$.

• 방송공학회논문지
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• 제25권3호
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• pp.374-385
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• 2020

본 논문에서 Equirectangular Projection(ERP) 영상으로 행동 인식을 할 때의 문제점들을 해결할 수 있는 전처리 기법을 제안한다. 본 논문에서 제안하는 전처리 기법은 사람 객체를 행동의 주체 즉, Object of Interest(OOI)로 가정하고, OOI의 주변 영역을 ROI로 가정한다. 전처리 기법은 3개의 모듈로 이루어져 있다. I) 객체 인식 모델로 영상 내 사람 객체를 인식한다. II) 입력 영상에서 saliency map을 생성한다. III) 인식된 사람 객체와 saliency map을 이용하여 행동의 주체를 선정한다. 이후 행동 인식 모델에 선정된 행동의 주체 boundary box를 입력하여 행동 인식 성능을 높인다. 제안하는 전처리기법을 사용한 데이터를 행동 인식 모델에 입력한 방법의 성능과 원본 ERP 영상을 입력한 방법의 성능을 비교하였을 때 최대 99.6%의 성능 향상을 보이며, OOI가 감지되는 프레임만을 추출하였을 때 행동 관련 영상 요약의 효과도 볼 수 있다.

• Computers and Concrete
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• 제1권3호
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• pp.325-354
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• 2004

Slabs in buildings and bridge decks, which are restrained against lateral displacements at the edges, have ultimate strengths far in excess of those predicted by analytical methods based on yield line theory. The increase in strength has been attributed to membrane action, which is due to the in-plane forces developed at the supports. The benefits of compressive membrane action are usually not taken into account in currently available design methods developed based on plastic flow theories assuming concrete to be a rigid-plastic material. By extending the existing knowledge of compressive membrane action, it is possible to design slabs in building and bridge structures economically with less than normal reinforcement. Recent research on building and bridge structures reflects the importance of membrane action in design. This paper describes the finite element modelling of membrane action in reinforced concrete slabs through optimisation of a simple concrete model. Through a series of parametric studies using the simple concrete model in the finite element simulation of eight fully clamped concrete slabs with significant membrane action, a set of fixed numerical model parameter values is identified and computational conditions established, which would guarantee reliable strength prediction of arbitrary slabs. The reliability of the identified values to simulate membrane action (for prediction purposes) is further verified by the direct simulation of 42 other slabs, which gave an average value of 0.9698 for the ratio of experimental to predicted strengths and a standard deviation of 0.117. A 'deflection factor' is also established for the slabs, relating the predicted peak deflection to experimental values, which, (for the same level of fixity at the supports), can be used for accurate displacement determination. The proposed optimised concrete model and finite element procedure can be used as a tool to simulate membrane action in slabs in building and bridge structures having variable support and loading conditions including fire. Other practical applications of the developed finite element procedure and design process are also discussed.

• 유통과학연구
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• 제16권8호
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• pp.69-77
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• 2018

Purpose - With growing competition in the service distribution industry, the importance of managing customer complaints has increased. If firms handle customer complaints effectively, they can strengthen customer loyalty and repurchase intention. Many studies have focused on customers expressing complaints, yet research on silent customers is scant. This study focuses on two types of complainers and non-complainers. In other words, this study is to examine the value of voice complaint intention and no-action intention. This study also investigates how perceptual and relational factors affect complaint intention. Research design, data, and methodology - This study was carried out using the survey with undergraduate students who have faced a service failure in a retail store(fast foods, electronics, apparel). And if such complaint were to occur again, respondents were asked about any possible action they would take. 300 questionnaires were distributed and a total of 279 respondents provided complete and usable data. The sample consisted of 158 males(56.6%) and 121 females(43.4%). The structural equation modeling analysis was used for the hypothesis test. Results - The results are as follows. First, attitude toward complaining, likelihood of successful complaint, and ease of complaint were positively related to voice complaint intention. Second, attitude toward complaining, likelihood of successful complaint, and ease of complaint were negatively related to no-action intention. Third, commitment was positively related to voice complaint intention but didn't have a significant negative impact on no action. Forth, voice complaint behavior reduced switching intention and no-action intention enhanced switching intention. Conclusions - The findings of this study confirm the value of complaint behavior and show voice complaint intention and no-action intention should be managed differently. Voice complaint intention is evaluated positively because it reflects customers' concerns about the company, while no-action intention is evaluated negatively. Attitude toward complaing is the most effective in increasing voice complaint intention and likelihood of successful complaint is a major factor in reducing no-action intention. Also, in explaining switching intention, voice complaint intention plays a more important role than no-action intention.

• Journal of Pharmaceutical Investigation
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• 제8권1호
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• pp.6-16
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• 1978

We obtained 4 kinds of extract fraction from Acanthopanacis Radicis Cortex and studied on the influence to the blood pressure of rabbit. These 4 fractions were obtained as follows; Fraction I was insoluble fraction by 99% ethanol from 80% methanol extract of Acanthopanacis Radicis Cortex, fraction II, precipitated fraction by ether from 99% ethanol soluble fraction of 80% methanol extract of Acanthopanaacis Radicis Cortex, fraction III, no precipitated fraction by ether from 99% ethanol soluble fraction of above 80% methanol extract and fraction IV, water extract of Acanthopanacis Radicis Cortex. All of fractions, when administered into ear-vein of rabbit, produced fall of blood pressure. Among these 4 fractions, although fraction III was not only the most potent but had the greatest efficacy, we observed the mechanism of hypotensive action of Acanthopanacis Radicis Cortex, making use of fraction II which was thought as a comparatively pure fraction. Hypotensive action of fraction II (APF II) was not affected by vagotominization but markedly inhibited by atropine. Pretreatment of bethanidine showed a tendency to weaken the depressor action of APF II, although it was not a significant result, but diphenhydramine did not influence APF II action. Phentolamine, guanethidine and chlorisondamine inhibited significantly the hypotensive action of APF II. APF II elicited the potentiation of norepinphrine pressor action dependent on the time-factor whereas it did not influence angiotesin pressor action. It is seemed that APF II exhibited hypotensive action, causing peripheral muscarinic-effect and centrally induced sympatholytic action.

• 대한약리학회지
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• 제22권2호
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• pp.135-143
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• 1986

저자는 적출관류 토끼 신장기능에서 칼슘의 역할과 furosemide의 이뇨작용에 미치는 영향을 관찰하여 다음과 같은 결과를 얻었다. hydralazine놔 verapamil을 주로 신혈관 저항의 감소로 이뇨작용을 나타냈다. furosemide를 hydralazine 또는 verapamil 병합투여시 뚜렷한 이뇨작용이 나타났으며 두군 사이에 차이는 없었다. quinidine은 신혈관 수축을 일으켰으나 이뇨작용이 나타났으며 furosemide의 이뇨작용을 항진시켰다. 칼슘제외된 관류액으로 관류시 칼슘은 신혈관 수축에도 불구하고 이뇨작용이 나타났으며 furosemide의 이뇨작용을 항진시켰다. quinidine은 칼슘이 제외된 상태에서 신장기능 및 furosemide의 이뇨작용에 영향을 미 치지 못하였으나 calcium 병합투여시 과도한 신혈관 수축으로 항 이뇨작용을 보였다. verapamil은 칼슘이 제외된 상태에서 약간의 이뇨작용을 보였지만 칼슘 및 furosemide의 이뇨작용을 변화시키지 못하였다. 이상의 성적은 적출관류 토끼 신장에서 칼슘, verapamil 및quinidine이 이뇨작용이 있으며 칼슘은 furosemide의 이뇨작용을 항진시킨다.

• 대한수학회보
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• 제26권1호
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• pp.47-52
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• 1989

Methods of Riemannian geometry has played an important role in the study of compact transformation groups. Every effective action of a compact Lie group on a differential manifold leaves a Riemannian metric invariant and the study of such actions reduces to the one involving the group of isometries of a Riemannian metric on the manifold which is, a priori, a Lie group under the compact open topology. Once an action of a compact Lie group is given an invariant metric is easily constructed by the averaging method and the Lie group is naturally imbedded in the group of isometries as a Lie subgroup. But usually this invariant metric has more symmetries than those given by the original action. Therefore the first question one may ask is when one can find a Riemannian metric so that the given action coincides with the action of the full group of isometries. This seems to be a difficult question to answer which depends very much on the orbit structure and the group itself. In this paper we give a sufficient condition that a subgroup action of a compact Lie group has an invariant metric which is not invariant under the full action of the group and figure out some aspects of the action and the orbit structure regarding the invariant Riemannian metric. In fact, according to our results, this is possible if there is a larger transformation group, containing the oringnal action and either having larger orbit somewhere or having exactly the same orbit structure but with an orbit on which a Riemannian metric is ivariant under the orginal action of the group and not under that of the larger one. Recently R. Saerens and W. Zame showed that every compact Lie group can be realized as the full group of isometries of Riemannian metric. [SZ] This answers a question closely related to ours but the situation turns out to be quite different in the two problems.

• 한국생활과학회지
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• 제6권1호
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• pp.111-127
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• 1997

This study was to examine home economics (HE) teachers' and the 1st-grade students' needs perception toward the purposes of HE education in middle school which has been practced since 1995 for both male and female students. This study, attempted (1) to analyze needs priority among the educational purposes of HE subject in relation to three systems of actions; (2) to compare differences between HE teachers' and students' perception concerning the degree of importance and achievement of the educational purposes of HE subject: and (3) to examine what they conceive as the problems In the current HE education. The survey was conducted with the samples of 600 1st-grade middle school students and 101 middle school HE teachers during the period of February-March 1996. The questionnaire used in this study was a modified version which had already been developed along with the 6th HE curriculum. For data analyses, SAS program was utilized to get Means and to perform both discrepancy test and t-test. The findings of this study were summarized as follows: first, with respect to each group's perception of the importance of the purposes related to three systems of action, HE teachers emphasized the importance of the purposes related to emancipatory action, while students placed more emphasis on the purposes related to technical action. Second, in terms of the degree of achievement, students had more positive perception on the degree of achievement of the purposes related to technical action than HE teachers did. Both groups marked low level of recognition on the degree of achievement of the purposes related to emancipatory action. Third, with respect to needs priority, HE teachers placed the first priority on emancipatory action, the second on technical action, and the last on communicative action: in the case of students, the first priority was on technical action, the second on communicative action, and the last on emancipatory action. In addition, the analysis of the opinions on the 6th curriculum revealed that most respondents found it necessary to secure adequate amount of classes for HE education. Also they shared the recongnition that HE curriculum should be renovated into the one which would fully appreciate the purposes of HE education from the perspective of the practical concerns of action which are distinct from the functional and technical concerns of passive learning. The findings of this study can serve as basic data for establishing the new purposes of HE education which put more emphasis on the purposes related to emancipatory action: as well as for developing an enhanced curriculum and reinforcing the identity of HE education.

• 한국콘텐츠학회논문지
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• 제15권11호
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• pp.658-671
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• 2015

본 연구는 블렌디드 액션러닝프로그램이 대학생의 자기주도적 학습능력 향상에 미치는 영향을 탐색하였다. 이를 위해 수도권 D 대학의 사범대학 학생들을 대상으로 실험집단 30명, 통제집단 30명을 구성하여 연구를 수행하였다. 연구대상의 평균연령은 22.3세이며, 2-4학년 재학생으로 인구통계학적 배경은 비교적 동질적이다. 교육사회학(교직과목) 수업에서 실험을 수행하였다. 연구는 학기 초에 자기주도적 학습 능력을 사전 검사하였다. 이후에 실험집단은 블렌디드 액션러닝프로그램으로 수업을 진행하였고, 통제집단은 액션러닝프로그램으로 수업을 진행하였다. 학기가 종료되는 시기에 사후 검사를 실시하였다. 자료 분석은 사전 검사 점수를 고려하여 집단 간 사후 검사 점수를 비교하기 위해 공분산분석(ANCOVA)을 수행하였다. 그 결과 첫째, 대학생들의 자기주도적 학습능력 향상을 위해서는 액션러닝프로그램 보다 블렌디드 액션러닝프로그램이 효과적인 것으로 나타났다. 둘째, 인지적, 경험적 수준이 낮은 학습자 대상의 수업에서는 액션러닝프로그램 보다 블렌디드 액션러닝프로그램이 더욱 효과적인 것으로 나타났다. 셋째, 학습자원 관리와 학습전략 활용 측면에서는 액션러닝프로그램과 블렌디드 액션러닝프로그램 공히 영향을 미치지 못하는 것으로 나타났다. 이상의 내용을 종합해볼 때 대학생의 자기주도적 학습능력을 향상하기 위해서는 다양한 교수방법 중 전통적 집단강의보다 학습자들의 참여 및 실천학습 방법인 액션러닝프로그램이 효과적인 교수방법이지만, 대학생들의 지적, 경험적 측면의 초보적 수준을 고려할 때 블렌디드 액션러닝프로그램의 적극적 활용이 요구된다.