• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.9
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• pp.1423-1431
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• 2001

Based on the exponential intervening variable, a new two-point approximation method is presented. This introduces the shifting level into each exponential intervening variable to avoid the lack of def inition of the conventional exponential intervening variables due to zero-or negative-valued design variables. Then a new quadratic approximation whose Hessian matrix has only diagonal elements of different values is proposed in terms of these intervening variables. These diagonal elements are determined in a closed form that corrects the typical error in the approximate gradient of the TANA series due to the lack of definition of exponential type intervening variables and their incomplete second-order terms. Also, a correction coefficient is multiplied to the pre-determined quadratic term to match the value of approximate function with that of the previous point. Finally, in order to show the numerical performance of the proposed method, a sequential approximate optimizer is developed and applied to solve six typical design problems. These optimization results are compared with those of TANA-3. These comparisons show that the proposed method gives more efficient and reliable results than TANA-3.

• Journal of Microbiology and Biotechnology
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• v.16 no.9
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• pp.1422-1428
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• 2006

An ABC transporter apparatus of the Gram-negative bacterial type I secretion pathway can be used as a secretory protein expression system in Escherichia coli. Four types of coexpression systems for the Pseudomonas fluorescens lipase gene, tliA, and its cognate ABC transporter gene cluster, tliDEF, were constructed. When the relative expression levels were changed by adding different concentrations of IPTG, the secretion (16.9 U/ml of culture) of TliA in E. coli [pTliDEFA-223+pACYC184] was significantly higher than E. coli [pKK223-3+pTliDEFA-184] secreting the lowest level of TliA (5.2 U/ml of culture). Maximal accumulation of the lipase secreted occurred in the mid-exponential phase, implying that the efficient protein secretion via an ABC transporter was restricted only to actively growing cells. Finally, the secretion level of TliA in E. coli [pTliDEFA-223+pACYC184] was increased to 26.4 U/ml by inducing gene expression at the culture initiation time. These results indicate that a significant increase in the ABC transporter-dependent protein secretion can be achieved by simply controlling the relative expression levels between the ABC transporter and its passenger protein, even in the recombinant E. coli cells.

• Water for future
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• v.11 no.1
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• pp.39-46
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• 1978

The approaching deep water wave heights and directions affect the wave energy which is carried to the coast. By studing the relations between the longshore wave energy theory and the evolution of coastline, writer can arrive following conclusion. The longshore lottoral drifting affects to a great deal the formation of the coast, and by investigating on the eastern coastal geomophorogy of korea, the theory was proued as a true and made it possible to an approaching to the subdivided classification of eastern coast of lorea. That is to asy that angle taken by the level between the wave crest line of prevailing wave(NE) and the coastline was measured as less than 15#, and in the area neighboring the river which served as source of Sand parrticles, there are grand scale formation of sand beach expectable, in the other hand the formation of sand beach in case of $35^{\circ}{\leq}{\alpha }o{\leq}55^{\circ}$ which represents the vivid phenomena of longshore littoral drifting was proved not influencial but rather transformed into a rocky coast. Depending on the above facts the writer classified general shape of the coast affected by the vivid wave action into the following three, (1) The equilibrium beach. (2) Erosinal beach. (3) Geomophorogical beach, and made the sandy and rocky coast are subdivided as S-A.B.C. and R-DEF.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.6A
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• pp.848-854
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• 2000

Network management in TMN concerns to the operating system and communication equipments in network, and defines them as objects. GDMO(guidelines for the Definition of Managed Objects) is used to describe those objects. GDMO is not directly used for managing the network, but translated into a language with object-oriented paradigm. And GDMO refers to ASN.1(Abstract Syntax Notation One) for manage objects. This paper presents design and implementation techniques for the translator which automatically translates the specification of ASN.1 and GDMO to the object-oriented language for generating MIB(Managed object Instance Base). This system, unlike the existing source code generator, is designed to generate various object-oriented languages automatically, which are used to generate Managed object Instance Base(MIB). And the system includes various graphic user interface to enhance the development environment of ASn.1 and GDMO

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.307-315
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• 2010

Although a substantial amount of studies have been carried out in order to improve the performance of IEEE 802.11, most of them focused on how to slowly decrease the Contention Window size, instead of resetting it to its initial value. Slow decreasing of the window size reduces the collision probability and increases the channel throughput. Therefore, it is difficult to achieve good results in a heterogeneous network which coexists with the original DCF. For instance, a Gentle DCF(GDCF) has good performance in a homogeneous environment, while it can hardly transmit frames in a heterogeneous environment including the original DCF. It is because the slow decreasing of the window size reduces the transmission probability. In this paper, we propose a Fast Recovery DCF(FRDCF) to solve this problem. In the FRDCF, the reset mechanism of the original DCF is maintained to keep the transmission probability high, while a new counter is used to enhance the performance of the wireless LAN. We prove that, compared with the GDCF, the FRDCF has better performance in a heterogeneous wireless LAN.

• Journal of the Korea Society of Computer and Information
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• v.19 no.9
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• pp.75-84
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• 2014

In this paper, we constructed a sensor network environment where various sensors are used. Then, we evaluated the performance when this environment adopted existing clustering algorithms that are designed for only single type sensors network. In our experiments, we considered two different types of the networks. In the first, all nodes are equipped with identical sensors. In the second, all nodes are equipped with three different types of sensors. We measured performance variations of several clustering schemes in accordance with sensor data accuracy, sensor node resource depletion timing, amount of available energy, node isolation ratio, and network lifetime. According to our performance analysis, we proved that existing clustering algorithms are partially inefficient to maintain the various-sensor network. Consequently we suggest that a new algorithm is required to take aim at the various sensor network.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.5
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• pp.1418-1425
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• 2004

The water extract of Chongmyung-tang has been traditionally used for treatment of memory-disorder in oriental medicine. This study was designed to investigate the protective mechanisms of Chongmyung-tang on β-amyloid or H₂O₂-induced cytotoxicity in Neuro 2A cells. The water extract of Chongmyung-tang significantly reduced both β-amyloid or H₂O₂-induced cell death and apoptotic characteristics through reduction of intracellular peroxide generation. Also, it inhibited the mitochondrial dysfunction including the disruption of mitochondria membrane permeability transition(MPT) and the modulation in expression of Bcl-2 family proteins in H₂O₂-treated H9c2 cells. Furthermore, pretreatment of quercetin inhibited the activation of caspase-3, in turn, degradation of ICAD/DFF45 were completely abolished in H₂O₂-treated cells. Taken together, that data suggest that the protective effects of the water extract of Chongmyung-tang against β-amyloid induced oxidative injuries may be achieved through modulation of mitochondrial dysfunction.

• The Plant Pathology Journal
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• v.36 no.5
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• pp.450-458
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• 2020

Pepper and tomato plants infected with two Clavibacter species, C. capsici and C. michiganensis have shown different patterns of disease development depending on their virulence. Here, we investigated how pepper and tomato plants respond to infection by the high-virulent or low-virulent Clavibacter strains. For this, we chose two strains of each Clavibacter species to show different virulence level in the host plants. Although low-virulent strains showed less disease symptoms, they grew almost the same level as the high-virulent strains in both plants. To further examine the response of host plants to Clavibacter infection, we analyzed the expression patterns of plant defense-related genes in the leaves inoculated with different strains of C. capsici and C. michiganensis. Pepper plants infected with high-virulent C. capsici strain highly induced the expression of CaPR1, CaDEF, CaPR4b, CaPR10, and CaLOX1 at 5 days after inoculation (dai), but their expression was much less in low-virulent Clavibacter infection. Expression of CaSAR8.2 was induced at 2 dai, regardless of virulence level. Expression of GluA, Pin2, and PR2 in tomato plants infected with high-virulent C. michiganensis were much higher at 5 dai, compared with mock or low-virulent strain. Expression of PR1a, Osmotin-like, Chitinase, and Chitinase class 2 was increased, regardless of virulence level. Expression of LoxA gene was not affected by Clavibacter inoculation. These results suggested that Clavibacter infection promotes induction of certain defense-related genes in host plants and that differential expression of those genes by low-virulent Clavibacter infection might be affected by their endophytic lifestyle in plants.

• Journal of KIISE:Software and Applications
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• v.32 no.8
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• pp.795-807
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• 2005

The classical approaches for computing Live Variable Analysis(LVA) use iterative algorithms across the entire programs based on the Data Flow Analysis framework. In case of Zephyr compiler, average execution time of LVA takes $7\%$ of the compilation time for the benchmark programs. The classical LVA algorithm has many aspects for improvement. The iterative algorithm for LVA scans useless basic blocks and calculates large sets of variables repeatedly. We propose the improvement of Iterative algorithm for LVA based on used variables' upward movement. Our algorithm produces the same result as the previous iterative algorithm. It is based on use-def chain. Reordering of applying the flow equation in DFA reduces the number of visiting basic blocks and redundant flow equation executions, which improves overall processing time. Experimental results say that our algorithm ran reduce $36.4\%\;of\;LVA\;execution\;time\;and\;2.6\%$ of overall computation time in Zephyr compiler with benchmark programs.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.462-469
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• 2010

Gas-liquid 2 phase processes are usually used in chemical, biochemical, environmental engineering and food process. For optimizing these processes, understanding bubble's precise movement and shape are needed. Bubble's movement and shape are effected by liquid's properties-viscosity, surface tension and bubble's properties-size, velocity. This paper deals with experimental data of bubble's movement and shape in high viscous silicone oil. Also, drag coefficient and deformation factor given by other researcher's papers and books are used to predicting and comparing bubble's terminal velocity, drag coefficient, deformation factor and shape with experimental value. Experimental data show that bubble moves faster when it moves in lower viscous silicone oil and it's drag coefficient is bigger when it moves in high viscous silicone oil. Bubble's shape is close to sphere when moving in high viscous silicone. Formulas proposed by Batchelor expect most accurate prediction for bubble's velocity and drag coefficient. Bubble's 2D shape predicted by Batchelor's energy balance, drag coefficient and deformation factor show excellent agreement with experimental bubble's 2D shape.