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In order to study the antiinflamatory efficacy of ketoprofen diesters (polyethylene glycol 400 and 1,000) and lysinate in comparison with that of ketoprofen, the effects on blood vessel perme ability in mice, granuroma formation in rats, swelling of rat hind paw and ulcer formation in rats were examined. As shown in results, the inhibitory effect of the diesters in blood vessel permeability was same as Rthat of ketoprofen. Granuloma formation induced by 2% carageenin was significantly inhibited by ketoprofen itself and the diesters, however, the exudate formation was markedly inhibited only diester 1,000. In carageenin induced rat paw edema test, the diesters exhibited antiinflamatory effect same as ketoprofen. In addition, the average ulcer index in rats were as follows in decreasing order; ketoprofen lysinate, the diester 400, ketoprofen itself and the diester 1,000.
Planting, transplanting, and harvesting are important processes for the successful production of farm products in Korea because those require the short term high labor intensity. In the automatic production system of the field or the green house, planting is the first process required to be automated considering subsequent operations such as transpalnting and harvesting. A proto type experimintal robotized seeder was designed and built to handle various sizes and shape of seeds. The developed seeder is automatically controlled with one chip micro-controller. System is composed of the transfer arm, pecker, and the equipments integrated with sensor such as hopper, feeder, counter, and shutter. System allows to control the number of seeds to be planted. Results of the developed experimental robotized seeder are as following : 1. For the adequate feeding and counting of seeds, components such as hopper, feeder, counter, and shutter were designed and built. 2. Kinematic motion of the transfer arm was analyzed and designed. 3. Picker was designed to dig and drop seeds into the soil by the open and close action of the bottom gate controlled by DC solenoid. Digging depth of the pecker was controlled by the transfer arm.
In recent years, a trend of DC-DC converter is studied mainly quasi resonant converter and multi resonant converter such as resonant type. But by using zero voltage and zero current method, these converter have voltage and current stress in the circuits. So the purpose of this paper is to reduce voltage and current stress, and to increase efficiency (about 5∼10%) rather than above converters. Experimental results show that active clamp mode PWM switching forward converter has minimum switching loss and conducting loss. The test results verify the simulation performance.
Experimental vapor pressure data reported in the literature for 10 kinds of n -paraffin (from methane through n-decane) have been rigorously analyzed and used to determine the constants A, B, C, D, and exponent n of the following equation in the modified form of Frost-Kalkwarf vapor pressure equation proposed by Chung and Thodos : In P_r = A -f- B / T_r + C In T_r + DT_r^n According to varying exponent n all four constants have been obtained for n-paraffin by the error analysis. This has provided us with the best n and four constants for each material. The average deviation is 0.34% and the total average deviation is 0.38% for 10 materials with n = 4.30 as the best fit for n-paraffin. Using relationship between constants C and D for n=4.30 the following vapor pressure equation has been obtained. In P_r= ( -0.938 In, T_r) D^3 + (T_r^4.3-16.5 in T_r-18.49 /T_r + 17.49) D + 3.82 In T_r where the constant D is acquired by employing the latter equation at normal boiling point. In order to obtain the calculated vapor pressure by the above equation, only the normal boiling point and the critical pressure and temperature are necessary to get an overall average deviation of 0.51% for 551 experimental vapor pressure points consisting of 10 kinds of n-paraffin.
The objective of this paper is to develop a computational model and a software for predicting fatigue growth life of collinear multiple surface cracks under constant amplitude loadings and variable amplitude loadings. After examining crack growth rate data for CT specimens and surface crack specimens, empirical equations for surface crack geometry are proposed to predict the crack growth rate. In order to verify the proposed algorithm, a life prediction program has been developed. Several case studies were performed to check the accuracy of the proposed model and to verify the usefulness of the developed program. A good agreement was observed between the numerical results based on the proposed model and the published experimental data.
The thesis presents the problem of new harmonic elimination method of P\V\i inverter f d induction motor system using walsh series. In other words, this thesis presented technique of the selective harmonics elimination (SHE) by W-FT series in three phase PWM inverter output waveform. A microprocessor(8086 CPC)-controlled three phase induction motor system in order to verify this algorithm is presented. It is designed for a three output voltage in the 1∼60Hz inverter with the 5th and 7th harmonics, 5th, 7th, 11th, and 13th harmonics eliminated, and with the fundamental wave amplitude proportional to the output frequency. As the results, the performance of the proposed method could eliminate the harmonics and reduce computation time which determines switching pattern. In inverters, dead time circuits are inserted in the switching signals to prevent the dc link shortage. This causes the "dead-time effect", the fundamental voltage drop and the generation of low order harmonics, this thesis is deals with quantative prediction of dead-time effect and its compensation in PWM inverters. The performance of the compensation circuits is conformed through the sir,.-elation and the experiment. In the future, the proposed PWM pattern by W-FT series, is effective not only to the induction but also to the other electromagnetic machine such as volta e regulator, UPS.
Solute distribution on the ∑3  and ∑5  tilt boundary in a-brass of Cu-Zn binary system was studied. In calculating the amounts of solute segregated around the grain boundary, the regular solution theory was applied to define atomic interaction and coincidence site lattice model was used for grain boundaty structure. The results are summarized as follows : 1) Around the gtain boundary of α-brass, the zinc concentration profile curve shows a damped oscillation because of the ordering tendency in a-brass which has a negative value of the heat of mixing. 2) In Zn profile curves, the width of damped oscillation in ∑5 boundary is wider than that in ∑3 boundary because of the different number of broken bonds in each boundaries. 3) As the excess energy of ∑5 boundary is larger than that of ∑3 boundary, solute concentration in ∑5 boundary is higher than that in ∑3 boundary.
Elastic-plastic fracture toughness J_IC, is used as an effective criterion for the integrity as sessment of cracked structure in the elastic-plastic regime. The objective of this paper is to investigate the effect of various parameters on J_IC values. The material used in the experiment was SA 508 forged steel manufactured for the nuclear pressure vessel. The variables used in the experiments were temperature, orientation, specimen type, specimen shape and thickness. Two types of specimens, CT and TPB, with 1T, 1/2T thickness, were fabricated. Fracture toughness tests were performed in the temperature range of 20-300℃. Test results show that the J_IC values are decreased as temperature is increased. However, the effects of orientation, specimen size, shape and side-groove were negligible.
The purpose of a solar tracking system is to control the attitude of a space vehicle so that it will track the sun with high accuracy. In this paper, tracking of the sun in one plane is accomplished, an iterative procedure for control modellig of solar tracking system is presented by simultaneous differential equations and transfer functions. Also a program for obtaining a state-space representation is developed. A program for computation of state variables is based on the use of a 4th-order Runge-Kutta numerical integration algorithm included subroutines. It is applicable for the nonlinear time-variant case by appropriate modification of the subroutine. Computer simulation results are shown for the dynamic characteristics of vehicle system, armature -controlled DC motor and controller. Althogh certain interesting results are well established and documented, it is still a difficult task in the hardware realization.
The historical development of small farm economy has many different aspects such as socio-economic as well as political situations of the country. The small farm economic problem is not only dependent on the cultivated area of agricultural products, but also the society, where the farms are existing now. It might be impossible to compare between agricultural and industrial production. Agriculture is handled with living things, such as plants as well as animals. Therefore it is possible to increase agricultural production in small area of farm land, if the farm manager has enough capacities to do so. Therefore, the small farm problem is not only social and economic problem of the society but also the personal problem of farm managers.