• Architectural research
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• v.8 no.2
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• pp.37-42
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• 2006

Starting from the quadratic optimal control algorithm, this study obtains the relation of the performance index for constrained systems and Gauss's principle. And minimizing a function of the variation in kinetic energy at constrained and unconstrained states with respect to the velocity variation, the dynamic equation is derived and it is shown that the result compares with the generalized inverse method proposed by Udwadia and Kalaba. It is investigated that the responses of a 10-story building are constrained by the installation of a two-bar structure as an application to utilize the derived equations. The structural responses are affected by various factors like the length of each bar, damping, stiffness of the bar structure, and the junction positions of two structures. Under an assumption that the bars have the same mass density, this study determines the junction positions to minimize the total dynamic responses of the structure.

• Journal of Institute of Control, Robotics and Systems
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• v.4 no.1
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• pp.105-112
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• 1998

Regarding the measure of dexterity of robot manipulators, two geometric tools, manipulability ellipsoids and manipulability polytopes, are examined and compared with each other. Even though the manipulability ellipsoid approach is the most widely used technique, it is shown that the manipulability ellipsoid transforms the inexact joint velocity constraints into task space and so it may fail to give an exact measure of dexterity and optimal direction of motion in task space. After showing that the polytope approach can handle such problems, we propose a practical polytope method which can be applied to 3-dimensional task space in general. The relation between manipulability ellipsoids and manipulability polytopes are also explored for a redundant case and a non-redundant one.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.659-664
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• 1994

In order to predict gas hold-up and oxygen transfer rate during sisomicin fermentation employing air lift fermentor, simulated media similar to fermentation broths in rheological proper- ties were prepared and used. Rheological properties of fermentation broths from 40 hours and 60 hours of cultivation were analyzed by applying to Power's Law equation. Regardless of addition and no addition of MgSO$_{4}$, the tendencies, that n value was decreased and K value was increased as aeration rate was increased, were shown. Simulated media of twelve different fermentation broths were formulated in a range of 0.7 to 2.1% CMC, and the values of gas hold-up and k$_{L}$a depending on superficial air velocity were measured using these simulated media. And the relation- ships, $\varepsilon$=$\alpha$U$_{Gr}$$\beta$, K$_{L}$a=$\gamma$U$_{Gr}$$\delta$ were obtained, and these equations are thought to be used to predict the values of gas hold-up and k$_{L}$a during fermentation.

• Journal of Biomedical Engineering Research
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• v.11 no.2
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• pp.269-276
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• 1990

This study describes the battery functional test in order to explore vestibular oculomotor system. These tests are the following : a) acceleration test by using a pseudorandom stimulus. b) caloric test by considering both the constant temperature variation in the semicircular canals for a short time and the only head movement, to the fore and the back, for the ear ir- rigation, which gave us two types of stimulus (cold and warm) according to the only head position. c) optokinetic test by continuous constant velocity displacement of a large image fill- ing the entire subject's visual field. With relation to the clinical practices, some results of research programs which are at present in progress are presented.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.1
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• pp.12-17
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• 2002

Abstract The flow of liquid and vapor is investigated in trapezoidal grooves. The effect of variable shear stress along the interface of the liquid and vapor is studied for both co-current and counter-current flows. Velocity contours and results for the friction are obtained for both trapezoidal grooves. An approximate relation that was previously utilized for the friction for the liquid was modified to obtain accurate agreement with the results for trapezoidal grooves.

• Korean Journal of Veterinary Research
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• v.47 no.1
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• pp.99-102
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• 2007

A 3-year-old, intact female, Shih-tzu dog was presented with a 15-day history of vomiting,depression, and anorexia. On physical examination, systolic ejection murmurs with precordial thril atthe left heart base were detected. A diagnosis of congenital pulmonic stenosis (PS) was made mainlyfrom the thoracic radiography, electrocardiography, and echocardiography. On complete blood counts andconfirmed that main pulmonary artery was tremendously buldged and electrocardiography was suggestiveof severe right ventricular hypertrophy. Echocardiographic findings revealed the pulmonic valve stenosiscontaining valvular dysplasia and poststenotic dilation. On Doppler echocardiography, ejection velocityof the lesion accounted for 3.38 m/sec, meaning mild velocity through the stenotic area. The dog'sproblem and resulted in death. However, there has been no reliable relation between PS and CRF. Primarymalformation of pulmonic valve was confirmed at necropsy after death.

• Journal of the korean Society of Automotive Engineers
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• v.4 no.2
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• pp.58-68
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• 1982

It is well known to diesel engineers that the heat release pattern is one of the most important factors affecting engine performance. Thorough research in heat release pattern has materially helped the progress in high-speed diesel engine development . This paper is based on the research conducted at KAIST and Daewoo Heavy Industry last year. The purpose of this paper is to determine the heat release pattern in combustion chamber of MAN M type, the famous low-noise engine. Thermodynamic cycle simulation was performed using Whitehous-Way's heat release pattern with modified coefficients and Annand's heat transfer model. Instantaneous temperature and pressure of gas in cylinder could be determined by the numerical solution of simultaneous equation of mass conservation, equation of energy conservation, and state equation of ideal gas. Calculated results were compared with measured values in some details emphasizing upon the factors affecting rate of heat release. The agreement was fairly good and revealed why M type should have lower burning velocity at the early part of combustion in spite of high injection rate. Additional results by parametric studies were given in relation to fuel injection conditions for further application to engine development.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.718-722
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• 2014

A method for estimating the cylindrical shape of a sound radiator is presented. It assumes that sound field can be measured by a linear array. A sound field, due to the radiator vibrating with uniform velocity, can be determined by its shape, size, and orientations. Measured data also can be varying from the array's position. To predict the shape of radiators from these measured data, mathematical relation between geometric parameter and measured information is needed. Assume that a radiator is cylinder, the magnitude and phase of measured pressure is related with the length and diameter of radiator, respectively. In this paper, the method for estimating length and shape of a finite cylinder by using its radiated pressure is proposed and verified through experiment.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.03a
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• pp.1190-1197
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• 2009

Design parameters related to Yano's method(1984, 1985), one of experimental approaches having been used widely in Korea to estimate sedimentation and consolidation of dredged and reclaimed ground, were analyzed and their propriety were reassessed in this paper. Data analyses were performed on the basis of the settling test results using samples from the west coastal area of Korea. From analysis of results, for specific characteristics of these dredged and reclaimed marine soft clays, co-relations of initial water content - coefficient of sedimentation/ consolidation - initial setting velocity were evaluated. Relation between height of soil solid and surface height of slurry at the stages of initiation and termination of consolidation was also assessed. Finally ranges and average values of these design parameters were evaluated and typical empirical equations between these design parameters were also proposed.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.2
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• pp.103-111
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• 2006

To optimize the ventilation and smoke control systems in subway equipped with platform screen door, the technology to analyze the unsteady tunnel flow caused by running of train should be developed. The development of model experiment and numerical analysis technique with relation to unsteady flow of subway were presented. The pressure and air velocity changes in 1/20-scaling experiment unit were measured and results were comparied to those of 3-D unsteady numerical analysis applied with sharp interface method. The experimental and numerical results were quantitatively similar and it would be reasonable to apply sharp interface method to analyze the unsteady flow in subway equipped with platform screen door.