• Microbiology and Biotechnology Letters
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• v.9 no.1
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• pp.45-50
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• 1981

The effect of growth and the carbon sources including the molar ratio of fructose to glucose was studied for the maximization of inosine-5'-monophosphate (5'-IMP) production from Brebibacterium ammoniagenes D-21530. According to experimental results, fructose was more efficient to 5'-IMP accumulation than glucose, while the latter was better for the cell growth than the former. To synchronously use glucose and fructose as carbon source is to optimally control the cell growth and maximum production of 5'-IMP without change of other conditions. The optimal weight percent of fructose to sum of glucose and fructose was 20～40%, and the productivity improvement over the utilization of fructose was about 40%. And also the optimality of purine base such as adenine and guanine were considered. The optimal concentrations of adenine and guanine were near 50㎎/l.

• Journal of Korean Society for Quality Management
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• v.39 no.3
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• pp.400-411
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• 2011

Process variables are factors in an experiment that are not mixture components but could affect the blending properties of the mixture ingredients. For example, the effectiveness of an etching solution which is measured as an etch rate is not only a function of the proportions of the three acids that are combined to form the mixture, but also depends on the temperature of the solution and the agitation rate. Efficient designs for the mixture components-process variables experiments depend on the mixture components-process variables model which is called a combined model. We often use the product model between the canonical polynomial model for the mixture and process variables model as a combined model. In this paper we propose three starting models for the mixture components-process variables experiments. One of the starting model we are considering is the model which includes product terms up to cubic order interactions between mixture effects and the linear & pure quadratic effect of the process variables from the product model. In this paper, we propose a method for finding robust designs and practical designs with respect to D-, G-, and I-optimality for the various starting combined models and then, we find practically efficient and robust designs for estimating the regression coefficients for those models. We find the prediction capability of those recommended designs in the case of three components and three process variables to be good by checking FDS(Fraction of Design Space) plots.

• Journal of KIISE:Software and Applications
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• v.34 no.3
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• pp.235-245
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• 2007

UUV(Unmanned Underwater Vehicle) should possess an intelligent control software performing intellectual faculties such as cognition, decision and action which are parts of domain expert's ability, because unmanned underwater robot navigates in the hazardous environment where human being can not access directly. In this paper, we suggest a RVC intelligent system architecture which is generally available for unmanned vehicle and develope an autonomous navigation system for UUV, which consists of collision avoidance system, path planning system, and collision-risk computation system. We present an obstacle avoidance algorithm using fuzzy relational products for the collision avoidance system, which guarantees the safety and optimality in view of traversing path. Also, we present a new path-planning algorithm using poly-line for the path planning system. In order to verify the performance of suggested autonomous navigation system, we develop a simulation system, which consists of environment manager, object, and 3-D viewer.

• KDI Journal of Economic Policy
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• v.26 no.2
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• pp.63-104
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• 2004

Economists have long been involved in various studies, theoretical and empirical, on the economic gains from innovative activities and as their outcome, intellectual properties. In Korea, however, research in this field has experienced rather slow progress, partly due to the lack of data availability and the awareness of its importance. This study attempts to measure the economic impact of patents on market value of firms from a microeconomic point of view. Analyses are performed to examine the ex-ante market valuation of patent acquisition activities by investigating the effect of patent acquisitions on daily stock prices as well as on annual market values. The study on the effect of a disclosure of granted patents on daily stock prices reveals that the economic value of a firm's patent acquisition is fairly high. The study on listed firms also reveals that a firm's patent registration stock has a positive and statistically significant effect on its year-end market value. Therefore, it can be concluded that the analysis performed in this study supports the validity of Korea's current patent system. The result, however, does not guarantee the optimality of current system. Studies on various aspects of intellectual property should follow to shape the system into a socially optimal one.

• Explosives and Blasting
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• v.30 no.2
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• pp.29-42
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• 2012

Variables influencing the free face movement due to rock blasting include the physical and mechanical properties, in particular the discontinuity characteristics, explosive type, charge weight, burden, blast-hole spacing, delay time between blast-holes or rows, stemming conditions. These variables also affects the blast vibration, air blast and size of fragmentation. For the design of surface blasting, the priority is given to the safety of nearby buildings. Therefore, blast vibration has to be controlled by analyzing the free face movement at the surface blasting sites and also blasting operation needs to be optimized to improve the fragmentation size. High-speed digital image analysis enables the analyses of the initial movement of free face of rock, stemming optimality, fragment trajectory, face movement direction and velocity as well as the optimal detonator initiation system. Even though The high-speed image analysis technique has been widely used in foreign countries, its applications can hardly be found in Korea. This thesis aims at carrying out a fundamental study for optimizing the blast design and evaluation using the high-speed digital image analysis. A series of experimentation were performed at two large surface blasting sites with the rock type of shale and granite, respectively. Emulsion and ANFO were the explosives used for the study. Based on the digital images analysis, displacement and velocity of the free face were scrutinized along with the analysis fragment size distribution. In addition, AUTODYN, 2-D FEM model, was applied to simulate detonation pressure, detonation velocity, response time for the initiation of the free face movement and face movement shape. The result show that regardless of the rock type, due to the displacement and the movement velocity have the maximum near the center of charged section the free face becomes curved like a bow. Compared with ANFO, the cases with Emulsion result in larger detonation pressure and velocity and faster reaction for the displacement initiation.