• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.51-56
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• 2015

To assess downward positions of water spray for the small-scale release of chlorine gas, dispersion coefficients for the Gaussian dispersion model were validated at the small-scale release experiment. And the downwind distances of water spray were assessed with the simulated results. As results, the Gaussian plume model using the Briggs' dispersion coefficient well estimated the dispersed characteristics for small-scale release of chlorine gas. The best adequate downwind position of water spray is the position of the maximum concentration of chlorine at the ground level. And the adequate vertical and horizontal dimensions of water spray consider the maximum width and height of cloud.

• 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.

• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.59-63
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• 2007

With the recent increasing demand on the high-performance buildings, there has been a rapid growth in the application of the Computational Fluid Dynamics to the Building design. The conceptual ventilation design of the underground parking area currently under construction is validated using the CFD-ACE+. It has been found that the conceptual ventilation design quantitively satisfies the legal standards. However, the highly concentrated region of CO is predicted. The positions and blowing directions of ventilating lane are changed based on the previously predicted concentration distributions. The highly concentrated region of CO is slightly reduced, but not much change has been observed. Two more fang are installed and the positions and blowing directions of the fans are modified so that the highly concentrated region of CO is minimized.

• 한국정보디스플레이학회:학술대회논문집
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• 2002.08a
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• pp.289-292
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• 2002

A new technique to construct an auto-stereoscopic display that offers massive horizontal parallax images is proposed Multiple telecetnric imaging systems are arranged in a modified 2D array. The horizontal parallax images displayed by LCD panels are imaged to be superimposed on a 3D screen. All parallax images are displayed in the different horizontal directions because all imaging systems have different horizontal positions. The difference of the vertical display directions due to the imaging system's vertical positions is canceled by a vertical diffuser placed at the 3D screen. Observers can percept 3D images with the binocular disparity, the vergence, and the smooth motion parallax. In addition, the accommodation function may also work because a number of parallax images are displayed with a very small angle interval in the horizontal direction. A prototype 3D display including 64 color LCD panels was constructed.

• Korean Management Science Review
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• v.26 no.1
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• pp.7-20
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• 2009

The framework of "blue ocean strategy (Kim and Mauborgne, 2005)" applies to not only business firm level but also region or regional industry level. The paper suggests an approach of survey-based blue ocean strategy formulation. The result from survey on customer group and non-customer group gives information on positions of value curves for regions on strategy canvas and hints on how to reposition the focal region's value curve for both increases in value for customers and decreases in cost for local government, i.e., value innovation. In the context of rafting industry in Korea, this study shows the process how blue ocean strategy can be formulated with results from the survey on customers and business people in rafting industry. Relative positions of value curves on strategy canvas and importance scores for strategy elements provides the local government in region A with implications on which elements to raise or to reduce to create "blue ocean" in rafting industry under fierce inter-region competition.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.196-202
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• 2000

In the precision point synthesis of mechanisms, it is usually required to solve a system of polynomial equations. With the aid of efficient algorithms such as elimination, it is possible to obtain all the solutions of the equations in the complex domain. But among these solutions only real values can be used fur real mechanisms, while imaginary ones are liable to be discarded. In this article, a method is presented, which leads the imaginary solutions to real domain permitting slight alteration of prescribed positions and eventually increases the number of feasible mechanisms satisfying the desired motion approximately. Two synthesis problems of planar 4-bar path generation and spatial 7-bar motion generation are given to verify the proposed method.

• Korean Journal of Pharmacognosy
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• v.11 no.3_4 s.43
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• pp.153-162
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• 1980

1) The hydroxy-substitution in the simple phenolic compounds follows an additivity rule in the chemical shifts of their aromatic carbon atoms. In para-and ortho-effects is a good agreement between calculated and measured values, but the meta-effect is not certain. 2) The additivity rule was applied to assign the chemical shifts of catechins. 3) The nuclear overhauser effect was applied to assign the chemical shifts of C-8 and C-6 atoms of catechins and their polymer. The signal of C-8 is lower in intensity and appear in lower field than C-6. 4) The results of the NOE were applied to determine the bonding positions of catechin units in the catechin dimer and trimer. The bonding positions are C-8a and C-8b atoms of the second and third catechin units. 5) It was tried to determine the conformation of the catechin dimer and trimer by analysing the signal shapes of C-3' and C-4' atoms in the catechol moieties. The catechol moieties lie in opposite side in the dimer and trimer structure. A combined analysis of $^{13}C-and\;^1H-NMR$ results lead to the suggestion that such a catechin polymer is a zigzag planar form.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2000.10a
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• pp.398-403
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• 2000

The design of multi-stage gear drives is a time-consuming process that includes additional design problems, which are not considered in the design of single-stage gear drives. In the previous research works, the authors have proposed a new algorithm to design multi-stage gear drives at the preliminary design phase. The proposed design algorithm automates the design process by integrating the dimensional design and the configuration design process. In the configuration design process, the positions of gears and shafts are determined by minimizing the geometrical volume (size) of a gearbox. However, various types of spatial constraints should be satisfied in practical design situation. To locate input and output shaft in specified positions is the typical example of such problems. In this paper, the authors show the formulations of spatial constraints applied to the design of four-stage gear drives. The design solution shows considerably good results, and the design system is confirmed to be readily applicable to practical design situation.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.5
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• pp.617-624
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• 2007

This paper presents a novel quadstable monolithic mechanism (QsMM) which provides four stable equilibrium positions within its operation range. The quadstable mechanism has been realized from the use of both X- and Y-directional bistable structures which use curved snapping beams. A millimeter-scale brass mechanism was fabricated by ultra-precision milling to test the quadstability and the displacement-load behavior, and the prototype clearly demonstrated four distinct stable positions in its millimeter-scale planar operation. We discuss the design concept, finite element simulation for static and transient responses, fabrication by ultra-precision milling, and experimental measurement of the proposed quadstable mechanism.

• Communications of Mathematical Education
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• v.22 no.1
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• pp.79-89
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• 2008

In this study, we study on various positions and equations of trisectors of angle. We analyze article related with trisector's equation of angle. We elaborate the article, investigate various case of angles, and find out new equations of trisectors of angle.