• Proceedings of the Korean Operations and Management Science Society Conference
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• 1995.04a
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• pp.869-879
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• 1995

The new field of learning control develops controllers that learn to improve their performance at executing a given task, based on experience performing this task. The simplest forms of learning control are based on the same concept as integral control, but operating in the domain of the repetitions of the task. In the previous paper, I had studied the use of such controllers in a decentralized system, such as a robot with the controller for each link acting independently. The basic result of the paper is to show that stability of the learning controllers for all subsystems when the coupling between subsystems is turned off, assures stability of the decentralized learning in the coupled system, provided that the sample time in the digital learning controller is sufficiently short. In this paper, we present two examples. The first illustrates the effect of coupling between subsystems in the system dynamics, and the second studies the application of decentralized learning control to robot problems. The latter example illustrates the application of decentralized learning control to nonlinear systems, and also studies the effect of the coupling between subsystems introduced in the input matrix by the discretization of the system equations. The conclusion is that for sufficiently small learning gain, and sufficiently small sample time, the simple learning control law based on integral control applied to each robot axis will produce zero tracking error in spite o the dynamic coupling in the robot equations. Of course, the results of this paper have much more general application than just to the robotics tracking problem. Convergence in decentralized systems is seen to depend only on the input and output matrices, provided the sample time is suffiently small.

• PNF and Movement
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• v.17 no.1
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• pp.31-39
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• 2019

Purpose: Cognitive function is a main concern for rehabilitation progression in individuals who have sustained brain damage, even among those whose motor function has returned after brain damage. The purpose of this study was to investigate how cognitive impairment relates to functional independence in postural stability and gait performance in patients with chronic hemiparetic stroke. Methods: This was an observational design in an outpatient rehabilitation hospital. Twenty-eight adults with chronic hemiparetic stroke, receiving a course in an outpatient rehabilitation program, participated in this study. They were divided into two groups (i.e., non-cognitive impairment and cognitive impairment groups) via a cut-off score of 23 or less on a mini-mental state examination. Functional independence was assessed with the timed up-and-go test (TUG), 10-meter walk test (10mWT), five times sit-to-stand test (FTSST), Berg balance scale (BBS), and modified Barthel index (MBI). The independent t-test was used for statistical analysis when comparing the two groups. Results: The cognitive impairment group had less functional independence, balance, and gait performance than those of the non-cognitive impairment group had. The former also showed a statistically significant decrease in their TUG score, FTSST score, BBS score, and MBI score compared to the latter, but not in their 10mWT score (p<0.05). Although the non-cognitive impairment group walked faster than the cognitive impairment group did, that difference was not statistically significant (p>0.05). Conclusion: The results of this study suggest that cognitive impairment relates to functional independence in postural stability and the activities of daily living. In rehabilitation settings, cognitive impairment would be considered a major component in therapeutic rehabilitation to overcome the patients difficult physical problems and to treat for improving functional independence more after stroke.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.10
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• pp.1038-1047
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• 2009

The development process of a gas generator for a 30-tonf pump-fed space liquid rocket engine is described. Starting from the development of an injector, followed by subscale and full-scale test specimens, the development of LOx/kerosene fuel-rich gas generator has been concluded successfully. Various analytical methods have been utilized in the course of design and the performance requirements have been verified experimentally through ignition tests, combustion performance and stability assessment tests and duration tests. The gas generator has proven its workability and stability within a defined operation window of varying chamber pressure and mixture ratio and demonstrated compliance to the performance and life time requirements.

• Journal of Yeungnam Medical Science
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• v.11 no.1
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• pp.30-34
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• 1994

Local anesthetics produce pain during infiltration into skin. The relationship between local anesthetic-induced pain and pH of the local anesthetic solution has not been fully investigated. Commercial preparation of local anesthetics are prepared as acidic solutions of the salts to promote solubility and stability. And the acidity of local anesthetic solition may be related with the pain during infiltration of the solutione. So, we tried to neutralize the lidocaine hydrochloride solution which is one of the most frequently used local anesthetic agent. Sodium bicarbonate was used for neutralization. Sodium bicarbonate was mixed with lidocaine hydrochloride until the resulting pH of the solution become 7.4 which is identical to the acidity of body fluid. To identify the effect of neutralized lidocaine solution, we had a course of double blind test to 6 volunteers. Both forearm of each volunteer were injected with neutralized lidocaine and plain one, and the degree of pain was estimated by each volunteers. According to subjective description by the volinteers, everyone felt neutralized lidocaine injection site was less painful than plain lidocaine. We concluded that we could reduce pain from infiltration of lidocaine hydrochloride by neutralization of the anesthetic solution with sodium bicarbonate.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.1
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• pp.27-37
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• 2013

CFCs (Chlorofluorocarbons) and HCFCs (Hydrochlorofluorocarbons) that are chemically stable were proven to be a greenhouse gases that can destroy ozone layer. On the other hand, HFCs (Hydrofluorocarbons) was developed as an alternative refrigerant for them, but HFCs still have a relatively higher radiative forcing, resulting in a large Global Warming Potential (GWP) of 1,300. Current regulations prohibit production and use of these chemicals. In addition, obligatory removal of existing material is in progress. Methods for the decomposition of these material can be listed as thermal cracking, catalytic decomposition and plasma process. This study reports the development of low cost and high efficiency plasma scrubber. Stability of steam plasma generation and effect of plasma parameters such as frequency of power supply and reactor geometry have been investigated in the course of the development. Method for effective removal of by-product also has been investigated. In this study, elongated rotating arc was proven to be efficient in decomposition of HFCs above 99% and to be able to generate stable steam plasma with steam contents of about 20%.

• Journal of the Korean Home Economics Association
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• v.40 no.12
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• pp.1-11
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• 2002

This paper is intended as an analysis of the Chapter on Family in textbooks of a Middle school course at the aspect of Parson's Structural Functionalism Theory. In this analysis, We'd like to explore how the value of family is expressed in the Art-Home Economics textbooks. Generally, family is a subsystem in the structural system of whole society and family has two main functions to promote stability and equilibrium from the Parson's Structural Functionalism Theory point of view. Today, the concern with the Structural Functionalism Theory is dominantly reflected in textbooks, even though it has been proposed that the Structural Functionalism is not appropriate to explain family of modem society. Like that, the question now arises: the family history and interaction is ignored in the Structural Functionalism Theory. That is to say, There are limitations of Structural Functionalism Theory. The textbooks of Art-Home Economics was based on the revised curriculum has been severely changed in terms of external system of textbooks. But, we didn't know how much the view of the Structural Functionalism Theory is involved in textbooks. In this article, we analyze the view of the Structural Functionalism Theory in the Art- Home Economics textbooks using the Contents Analysis. At the same time, we find the confusion of family value revealed in textbooks.

• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.421-426
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• 2005

In this paper, we investigate the nonlinear dynamic behavior of TPP (thiamine pyrophosphate) riboswitches in E. coli (Escherichia coli). TPP riboswitches are highly conserved RNA regulatory elements, embedded within the 5’'untranslated region of three TPP biosynthesis operons. The three operons thiCEFSGH, thiMD, and thiBPQ are involved in the biosynthesis, salvage, and transport of TPP, respectively. TPP riboswitches modulate their expressions in response to changing TPP concentration, without involving protein cofactors. Interestingly, the expression of thiMD is regulated at the translational level, while that of thiCEFSGH at both levels of transcription and translation. We develop a mathematical model of the TPP riboswitch’s regulatory system possessed by thiCEFSGH and thiMD, so as to simulate the time-course experiments of TPP biosynthesis in E. coli. The simulation results are validated against three sets of reported experimental data in order to gain insight into the nature of steady states and the stability of TPP riboswitches, and to explain the biological significance of regulating at level of transcription or translation, or even both. Our findings suggest that in the TPP biosynthesis pathway of E. coli, the biological effect of down-regulating thiCEFSGH operon at the translational level by TPP riboswitch is less prominent than that at the transcriptional level.

• ALGAE
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• v.27 no.4
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• pp.249-258
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• 2012

Nongeniculate coralline red algae are a common element of the Brazilian coastal zone, especially associated to coral reefs. During the course of ecological studies at Parque Municipal Marinho do Recife de Fora, two species of non-geniculate Corallinales were the major organisms covering the reef. Analyses of the vegetative and reproductive features of the species were analyzed; indicating that one new species of the genus Lithothamnion is proposed here based on the combination of several features associated with anatomy of the tetrasporangial conceptacles in relation to other species of the genus for which modern accounts are available. This new proposal along with other new species, new combinations and range extension of some species of the genus based in similar features clearly suggest that stability in species delimitation is possible. The second species found Pneophyllum conicum represents a range extension of more than 6,000 km from the Pacific in to the Atlantic Ocean suggesting that some nongeniculate species are widely distributed. The occurrence and abundance of these species supports and emphasizes the need for an extensive taxonomic reassessment of coralline red algae in the context of Brazilian coral reef biodiversity.

• Plant Journal
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• v.8 no.2
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• pp.52-58
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• 2012

Pipe means the connection of the tube in order to transfer fluid from one device to another device. The piping stress analysis is to analyze the structural stability considering the location and the features of piping support after completing the piping design, The allowable stresses comply with the requirements of the relevant standards by examining whether the support of the function and location of pipe or re-operation is confirmed. Allowable stresses are to make sure that the maximum stress should not exceed the allowable stress presented in the ASME B31.1 POWER PIPING code. ASME B31.1 POWER PIPING code ensures a smooth stress analysis can be performed during the initial pipe stress analysis as provided in the case of straight pipe to the horizontal distance between the supports. However, because there is no criteria set in the case of curved pipe, the optimum pipe supporting points were studied in this paper. As mentioned about the curved pipe, loads applied to the support of the position of 17% and 83% of the position relative to the elbow part have results similar to the load acting on the support of straight pipe.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.6
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• pp.376-385
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• 2001

Considerable attention has been focused in recent years upon the field of biosorption for the removal of metal ions from aqeous effluents. Compared to other technologies, the advan-tages of biosortption are the high purity of the treated waste water and the cheap raw material. Really, the first major challenge for the biosorption field is to select the most promising types of biomass. Abundant biomass types either generated as a waste by-product of large-scale industrial fermentations particularly fungi or certain metal-binding seaweeds have gained importance in re-cent years due to their natural occurrence, low cost and, of course good performance in metal biosorption. Industrial solutions commonly contain multimetal systems or several organic and in organic substances that form complexes with metals at relatively high stability forming a very complex environment. When several components are present, interference and competition phe-nomena for sorption sites occur and lead to a more complex mathematical formulation of the process. The most optimal configuration for continuous flow-biosorption seems to the packed-bed column which gets gradually from the feed to the solution exit end. Owing to the com-petitive ion exchange taking place in the column, one or more of the metals present even at trace levels may overshot the acceptable limit in the column effluent before the breakthrough point of the trargeted metal. Occurrence of 'overshoot's and impact on havey metal removal has not been analyzed enough. New trends in biosorption are discussed in this review.