• Microbiology and Biotechnology Letters
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• v.21 no.4
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• pp.354-365
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• 1993

A novel control method with automatic tuning of PID controller parameters has been developed for efficient regulation of dissolved oxygen concentration in fed-batch fermentations of Escherichia coli. Agitation speed and oxygen partial pressure in the inlet gas stream were chosen to be the manipulated variables. A heuristic reasoning allowed improved tuning decisions from the supervision of control performance indices and it coule obviate the needs for process assumptions or disturbance patterns. The control input consisted of feedback and feedforword parts. The feedback part was determined by PID control and the feedforward part is determined from the feed rate. The proportional gain was updated on-line by a set of heuristics rules based on the supervision of three performance indices. These indices were output error covariance, the average value of output error, and input covariance, which were calculated on-line using a moving window. The integral and derivative time constants were determined from the period of output response. The specific growth rate was maintained at a low level to avoid acetic acid accumulation and thus to achieve a high cell density. The specific growthe rate was estimated from the carbon dioxide evolution rate. In fed-batch fermentation, the simutaneous control of dissolved oxygen concentration (at 0.2; fraction of saturated value) and specific growth rate (at 0.25$hr^{-1}$) was satisfactory for the entire culture period in spite of the changes in the feed rate and the switching of control input.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.3
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• pp.233-238
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• 2001

This paper deals with demand forecasting of parts in an automobile model which has been extinct. It is important to estimate how much inventory of each part in the extinct model should be stocked because production lines of some parts may be replaced by new ones although there is still demands for the model. Furthermore, in some countries, there is a strong regulation that the automobile manufacturing company should provide customers with auto parts for several years whenever they are requested. The major characteristic of automobile parts demand forecasting is that there exists a close correlation between the number of running cars and the demand of each part. In this sense, the total demand of each part in a year is determined by two factors, the total number of running cars in that year and the failure rate of the part. The total number of running cars in year k can be estimated sequentially by the amount of shipped cars and proportion of discarded cars in years 1, 2,$\cdots$, i. However, it is very difficult to estimate the failure rate of each part because available inter-failure time data is not complete. The failure rate is, therefore, determined so as to minimize the mean squared error between the estimated demand and the observed demand of a part in years 1, 2,$\cdots$, i. In this paper, data obtained from a Korean automobile manufacturing company are used to illustrate our model.

• Environmental Analysis Health and Toxicology
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• v.15 no.3
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• pp.69-80
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• 2000

ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

• Journal of Power Electronics
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• v.3 no.2
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• pp.99-114
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• 2003

This paper presents a feasible development on a highly accurate quick response adjustable speed drive implementation fur general purpose induction motor which operates on the basis of sensorless slip frequency type vector controlled sine-wave PWM inverter with an automatic tuning machine parameter estimation schemes. In the first place, the sensorless vector control theory on the three-phase voltage source-fed inverter induction motor drive system is developed in slip frequency based vector control principle. In particular, the essential procedure and considerations to measure and estimate the exact stator and rotor circuit parameters of general purpose induction motor are discussed under its operating conditions. The speed regulation characteristics of induction motor operated by the three-phase voltage-fed type current controlled PWM inverter using IGBT's is illustrated and evaluated fur machine parameter variations under the actual conditions of low frequency and high frequency operations for the load torque. In the second place, the variable speed induction motor drive system, employing sensorless vector control scheme which is based on three -phase high frequency carrier PWM inverter with automatic toning estimation schemes of the temperature -dependent and -independent machine circuit parameters, is practically implemented using DSP-based controller. Finally, the dynamic speed response performances for largely changed load torque disturbances as well as steady state speed vs. torque characteristics of this induction motor control implementation are illustrated and discussed from an experimental point of view.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.5
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• pp.338-346
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• 2016

Signal transducer and activator of transcription 3 (STAT3) is associated with various human diseases, such as cancer, auto-immune disease, and intestinal inflammation. The limited and inadequate effect of standard approaches for treating inflammatory bowel disease (IBD) has prompted to develop alternative anti-colitis agents through inhibition of STAT3. Here, we show that gallic acid (GA), a 3,4,5-trihydroxybenzoic acid, markedly reduced phosphorylation of STAT3. Among the derivatives of benzoic acids, GA showed significant inhibition on STAT3 phosphorylation. In addition, GA ameliorated the dextran sodium sulfate (DSS)-induced acute colitis as determined by the measurement of symptomatic and histological indices. The suppression of DSS-induced acute colitis by GA treatment may be related to the regulation of cytokines and growth factors. Furthermore, GA inhibited phosphorylation of STAT3 in the colon tissue of DSS-treated mice. These findings may be useful in comprehending the molecular action of GA on STAT3 phosphorylation and provide novel insights into the potential application of GA in the treatment of STAT3-related inflammatory disease, such as IBD.

• School Mathematics
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• v.16 no.1
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• pp.111-133
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• 2014

This study aims to explore mathematical belief system and core belief factors to be found. The mathematical belief system becomes an auto regulation device for students' using mathematical knowledge in mathematical situations and provides them with the context to perceive and understand mathematics. They have individual mathematical beliefs for each of mathematics subject, mathematical problem solving, mathematical teaching and learning and self-concept, and these beliefs of students construct mathematical belief system according to mutual relationships among the mathematical beliefs. Using correlation analysis and multiple regression, mathematical belief system was structuralized and core belief factors were found. Mathematical belief system is structuralized and, as a result the core belief factors that are psychological centrality of high school students' mathematical belief system are found to be persistence, challenge, confidence and enjoyment. These core belief factors are formed on the basis of personal experiences and they are personal primitive beliefs that cannot be changed with ease and cannot be shared with other people but they are related with many other beliefs influencing them.

• Archives of design research
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• v.16 no.1
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• pp.281-288
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• 2003

Beyond the millennium industrial development affects all of our life, and the growth of the automobile among them provides us with convenience of the living. One, however, was regarded as important to recognize the safety of the parking rather today than any past, getting together with the increasing auto population into the popularization gradually. It was needed to develope an active system and safety equipment in order to protect against an accident because there were so many accidents during the parking about which one felt relief. The objectives of this study was to develop a supporting structure with high static friction, adapt to various road environments, such as an unpaved road, a wet paved road, controling an angle, considering a portable and moveable device in order to prevent an accident during parking. As it mentioned above, the novel supporting structure had four strengths rather than a previous supporting structure, a practical new design (1998 084336 B60C) The implication of the study was the inspiration from warning of the parking accident almost 10 % of the total traffic accident in Korea, tries to find a solution to a problem in order to decrease the parking accident, in addition, makes it regulation ,and it was implied to the orientation about the popularization and the practical use of the new supporting structure which was developed

• The Journal of Engineering Geology
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• v.21 no.4
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• pp.337-348
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• 2011

We examined temporal variations in and relationships among groundwater level, groundwater temperature, and electric conductivity, and estimated groundwater recharge at Jeju Island. The time lag and regulation time of groundwater level data revealed that monitoring well in Ansung (JM-AS) has the highest auto-correlation. The cross-correlations for electric conductivity-water level, precipitation-water level, and air temperature-water temperature revealed that monitoring well in Seogwi-2 (JR-SG2) (electric conductivity-water level), monitoring well in Hamo (JD-HM) (precipitation-water level), and monitoring well in Wonjongjang-2 (JT-WJJ2) (air temperature-water temperature) had the highest cross-correlations. The average groundwater recharge ratio was 39.61%, and the average groundwater recharge amount was 1,153,490,407 $m^3/yr$, which is consistent with the results of previous studies.

• Atmosphere
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• v.21 no.2
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• pp.185-196
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• 2011

The performance assessment in radiosonde observation on the special observation program (ProbeX-2009) is performed and the characteristics of precipitation using Auto Weather System (AWS) and radiosonde data in 2009 at the Ulleungdo are investigated. The launching time, observation time, and maximum altitude of radiosonde are satisfied with the regulation from Korea Meteorological Administration (KMA) and World Meteorological Organization (WMO) but the duration of observational time of radiosonde is much shorter than that of the ProbeX-2007 because the altitude of launching site is higher than others in 2007. From the analysis of trajectories of radiosonde, most radiosondes at the Ulleungdo tend to move into the east because the westerly prevail at the middle latitude. However, when the Okhotsk high is expanded to the Korean peninsula and the north-westerly winds strengthen over the East Sea as the subtropical high is retreated, radiosonde tends to move into the south-west and south-east, respectively. Maximum distance appears at the end of observation level before May but the level of maximum distance is changed into 100 hPa after June because the prevailing wind direction is reversed from westerly to easterly at the stratosphere during summer time. The condition of precipitation was more correlated with the dynamic instability except Changma season. Precipitation in 2009 at the Ulleungdo occurred under the marine climate so that total precipitation amounts and precipitation intensity were increased and intensified during nighttime. The local environment favorable for the precipitation during nighttime was while the wind speed at the surface and the inflow from the shoreline were strengthened. Precipitation events also affected by synoptic condition but the localized effect induced by topography was more strengthened at the northern part of Ulleungdo.

• Journal of Digital Contents Society
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• v.13 no.2
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• pp.159-167
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• 2012

Eye tracking technology tracks human eyes movements to understand user's intention. This technology has been improving slowly and should be used for a variety of occasions now. For example, it enables persons with disabilities to operate a computer with their eyes. This article will show a typical implementation of an eye tracking system for persons with disabilities, after introducing the design principles and specific implementation details of an eye tracking system. The article discussed the realization of self-adapting regulation algorithm in detail. The self-adapting algorithm is based on feedback signal controlling the lens movements to realize automatic focus, and to get a clear eyes image. This CCD camera automatic focusing method has self-adapting capacity for changes of light intensity on the external environment. It also avoids the trouble of manual adjustment and improves the accuracy of the adjustment.