• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.159-159
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• 2009

In this work, nitrogen and oxygen functionalities was introduced to the graphite nanofibers (GNFs) and their effect on electrocatalytic performance of the GNF supports for direct methanol fuel cells (DMFCs) was invesigated. The nitrogen and oxygen groups were introduced through the urea treatments and acid treatment, respectively. And, PtRu catalysts deposited on modified GNFs were prepared by a chemical reduction method. The catalysts were characterized by means of elemental analysis, nitrogen adsorption, and X-ray photoelectron spetroscopy (XPS). The structure and morphological characteristics of the catalysts were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). As a result, the Pt-Ru nanoparticles were impregnated on GNFs with good formation in 3-5 nm. And, the cyclic voltammograms for methanol oxidation revealed that the methanol oxidation peak varied depending on changes of surface functional groups. It was thus considered that the PtRu deposition was related to the reduction of PtRu and surface characteristics of the carbon supports. The changes of surface functional groups were related to PtRu reduction, significantly affect the methanol oxidation activity of anode electrocatalysts in DMFCs.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.1027-1032
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• 2019

This study aimed to analyze the prioritized area for the functional change of agricultural reservoir according to the rapid urbanization and social changes through the mapping method. Changwon-si, Gimhae-si, and Jinju-si in Gyeongnam province were selected as the study area, considering the results of land-use and cluster analysis. As the planning unit of management area, watershed was used and land coverage map from 1975 to 2015 were analyzed for changes of land use. The reduction ratio (%) of farmland was calculated for identifying the changes in 2013 compared to 1975. As a result, the reduction ratio was 11.9% for Changwon-si, 12.2% for Gimhae-si and 9.3% for Jinju-si, and the number of watershed having functionally reduced potential-area was relatively high in the proportion to the city size.

• Bulletin of the Korean Chemical Society
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• v.8 no.3
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• pp.162-165
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• 1987

The reduction rate of borohydride exchange resin (BER) was greatly enhanced in the presence of lithium salts. Thus 2-heptanone was reduced completely with BER-LiCl in 1 h at room temperature. However, no reduction was observed with BER alone under the same conditions. With this system, organic compounds containing various fuctional groups were examined in ethanol at room temperature. This study revealed that BER-LiCl system exhibits an excellent chemoselectivity for carbonyl group in the presence of other functional groups. Keto esters and epoxy ketones were reduced with BER-LiCl to give the corresponding hydroxy esters and epoxy alcohols with excellent yields. Selective reductions of carbonyl groups were also possible in the presence of other organic compounds containing functional groups such as 1-idooctane, 1-bromooctane, caproamide, hexanenitrile, nitrobenzene, n-butyl disulfide, dimethyl sulfoxide and 1-dodecene.

• Korean Journal of Mathematics
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• v.18 no.1
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• pp.87-96
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• 2010

We consider the semilinear biharmonic equation with Dirichlet boundary condition. We give a theorem that there exist at least three nontrivial solutions for the semilinear biharmonic boundary value problem. We show this result by using the critical point theory, the finite dimensional reduction method and the shape of the graph of the corresponding functional on the finite reduction subspace.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.145-149
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• 1987

The input-output relation for nonlinear systems can be explicitly represented by the Voltera functional series and it is characterized by the Volterra Kernels. A block diagram reduction method is introduced to determine the Volterra Kernels for the nonlinear systems represented by nonlinear differential equations. Degree of nonlinearity is defined and analyzed for the analysis of nonlinear systems.

• Clinics in Shoulder and Elbow
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• v.17 no.1
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• pp.2-9
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• 2014

Background: Indirect reduction technique offers a valid option in the treatment of proximal humerus fracture. The purpose of this study is to evaluate the functional outcome and the complication rate after indirect reduction and internal fixation of unstable proximal humeral fractures with use of a locking plate. Methods: Twenty four patients with acute proximal humerus fracture were managed with indirect reduction and internal fixation with a locking plate. The mean follow-up period was 15.5 months. Results: The anatomical reduction of the medial cortex buttress was seen in 16 patients (66%) of the Group A and the non-anatomical reduction was seen in 8 patients (33%) of the Group B. Mean union time was $3.2{\pm}1.9$ months; it was $2.2{\pm}0.6$ months in the Group A and $5.3{\pm}2.2$ months in the Group B (p < 0.05). In our series, there were 6 cases of complications and these include 2 cases of varus malunion, 2 cases of shoulder stiffness, 1 case of heterotrophic ossification, 2 cases of screw perforation and 1 case of impingement. Conclusions: We conclude from our studies that indirect reduction and internal fixation using locking plate for acute proximal humerus fracture can give good results with bony union and predictable good overall functional outcome. If the medial cortex buttress is well maintained, a better anatomical reduction would be achieved, the union would be prompted, the pain would be further reduced and the range of the motion would be recovered more promptly.

• Journal of the Korea Computer Industry Society
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• v.2 no.10
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• pp.1261-1268
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• 2001

Despite of various useful features, functional languages do not provide an efficient way of representing states. To improve expressiveness of functional language, it is required a method representing explicit state without violating of functional semantic properties. In this paper, imperative functional language, $\lambda$st-calculus is designed to represent states without compromising the properties of pure functional languages. And we construct an algorithm to reduce proposed imperative functional language. $\lambda$st-calculus model which is an extension of the $\lambda$-calculus model with explicit state constructor without violating their semantic properties. it improves expressiveness of syntax through a concept of state composition and simplified reduction rules.

• Carbon letters
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• v.6 no.1
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• pp.25-30
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• 2005

The electrosorption of U(VI) from waste water was carried out by using an activated carbon fiber (ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at a lower potential, the ACF was electrochemically modified in an acidic and a basic solution. Pore structure and functional groups of the electrochemically modified ACF were examined, and the effects of the modification conditions were studied for the adsorption of U(VI). Specific surface area of all the ACFs was decreased by this modification. The amount of the acidic functional groups decreased with a basic modification, while the amount increased a lot with an acidic modification. The electrosorption capacity of U(VI) decreased on the acid modified electrode due to the shielding effect of the acidic functional groups. The base modified electrode enhanced the capacity due to a reduction of the acidic functional groups. The electrosorption amount of U(VI) on the base modified electrode at .0.3 V corresponds to that of the as-received ACF electrode at .0.9 V. Such a good adsorption capacity was due to a reduction of the shielding effect and an increase of the hydroxyl ions in the electric double layer on the ACF surface by the application of negative potential.

• Journal of Applied Reliability
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• v.10 no.2
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• pp.107-122
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• 2010

Functional safety is the part of the overall safety of a system that depends on the system or equipment operating correctly in response to its inputs, including the safe management of likely operator errors, hardware failures, systematic failures, and environmental changes. One of the essential concepts of functional safety is Safety Integrity Level(SIL). It is defined as a relative level of risk-reduction provided by a safety function, or to specify a target level of risk reduction. In this paper, each element of SIL assessment will be defined. Based on each element, specific process of SIL selection will be established by using flowchart. The flowchart provides a SIL assessment guideline for functional safety engineers. The proposed theory will be verified by applying to a oil refining plant for SIL assessment.

• Journal of The Korean Society of Integrative Medicine
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• v.5 no.4
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• pp.21-30
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• 2017

Purpose : This research intends to identify the effects of game-based weight bearing exercises on balance, muscular activation, sit to stand to sit motions of stroke patients. Method : 30 patients who were diagnosed as hemiplegia by stroke less in than a year were sampled and they were classified into two group, one of which was game-based weight bearing balance exercise group, and the other was functional weight bearing exercise group. 15 people were randomly selected for each group. Each exercise was coordinated by this research for 8 weeks, 5 days a week. 3D motion analyzer was used to measure the sit to stand to sit motions and a stopwatch was used to measure the time for stand-up motions for 5 times. Result : In terms of analyzing sit to stand to sit motions by phases, game-based weight bearing balance exercise group showed significant reduction compared to functional weight-bearing exercise group in phase I, II, III, IV and total time. In terms of functional stand-up performance analysis, game-based weight bearing balance exercise group showed significant reduction compared to functional weight-bearing exercise group in 5 times stand-up examination. Conclusion : It was verified that game-based weight bearing balance exercise had positive impact on function recovery of stroke patients by enhancing sit to stand to sit capabilities. It is considered that game-based exercise was an effective intermediary for functional improvement of stroke patients, while also inducing consistent and voluntary participation by causing interest and motivation.