• Bulletin of the Korean Mathematical Society
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• v.54 no.1
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• pp.29-42
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• 2017

In this work, four circulant and quadratic double circulant (QDC) constructions are applied to the family of the rings $R_{k,m}$. Self-dual binary codes are obtained as the Gray images of self-dual QDC codes over $R_{k,m}$. Extremal binary self-dual codes of length 64 are obtained as Gray images of ${\lambda}-four$ circulant codes over $R_{2,1}$ and $R_{2,2}$. Extremal binary self-dual codes of lengths 66 and 68 are constructed by applying extension theorems to the ${\mathbb{F}}_2$ and $R_{2,1}$ images of these codes. More precisely, 10 new codes of length 66 and 39 new codes of length 68 are discovered. The codes with these weight enumerators are constructed for the first time in literature. The results are tabulated.

• Bulletin of the Korean Mathematical Society
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• v.50 no.5
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• pp.1711-1723
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• 2013

P. V$\acute{a}$mos called a ring R 2-good if every element is the sum of two units. The ring of all $n{\times}n$ matrices over an elementary divisor ring is 2-good. A (right) self-injective von Neumann regular ring is 2-good provided it has no 2-torsion. Some of the earlier results known to us about 2-good rings (although nobody so called at those times) were due to Ehrlich, Henriksen, Fisher, Snider, Rapharl and Badawi. We continue in this paper the study of 2-good rings by several authors. We give some examples of 2-good rings and their related properties. In particular, it is shown that if R is an exchange ring with Artinian primitive factors and 2 is a unit in R, then R is 2-good. We also investigate various kinds of extensions of 2-good rings, including the polynomial extension, Nagata extension and Dorroh extension.

• Journal of the Korean School Mathematics Society
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• v.4 no.1
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• pp.125-136
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• 2001

This research is about how the adapted learning of descriptive assessment problems influence on the extension of the ability of the students. As a result, adapted learning of descriptive assessment problems totally led to positive effect, and according to the analyses of behavioral objectives divided into knowledge, comprehension and problem solving, they had more effect on the ability of students' problem solving. Learning attitude of the students were changed into self-centered learning attitude and interest on the subject of mathematics were highly increased since the research had started. If we adapt this research to the learning of mathematics after we develop various problems that can develop creativity, I'm sure that it will be a effective way for both extension of the ability and problem solving ability of the students.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.428-431
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• 2004

Smart structural system is defined as structural system with a certain-level of autonomy relying on the embedded functions of sensors, actuators and processors, that can automatically adjust structural characteristics, in response to the change in external disturbance and environments, toward structural safety and serviceability as well as the extension of structural service life. In this study, carbon and glass hybrid fiber materials were investigated fundamentally for the applicability of self diagnosis in smart concrete structural system as embedded functions of sensors.

• Bulletin of the Korean Mathematical Society
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• v.52 no.6
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• pp.1839-1854
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• 2015

Brief developments in metrical fixed point theory are covered and a significant generalization of recent results obtained in [18], [27], [32] and [33] is established through an extension of the property (EA) to two sequences of self-maps using the notions of weak compatibility and implicit relation.

• Korean Journal of Mathematics
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• v.5 no.1
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• pp.49-54
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• 1997

In this paper we study the generalized Reidemeister number $R({\varphi},{\psi})$ for a self-map $({\varphi},{\psi}):(X,G){\rightarrow}(X,G)$ of a transformation group (X, G), as an extension of the Reidemeister number $R(f)$ for a self-map $f:X{\rightarrow}X$ of a topological space X.

• Korean Journal of Soil Science and Fertilizer
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• v.48 no.5
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• pp.509-514
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• 2015

Indicators of environmental conditions qualitatively and quantitatively describe the state of the environment and natural resources, and the OECD (Organization for Economic Cooperation and Development) has initiated and suggested AEIs (Agri-Environmental Indicators) to assess trends over time of the effects of agriculture on the environment and the effectiveness and efficiency of agricultural and environmental policy measures since 1990's. This study aims to develop the state indicators of water quality for agricultural water, surface and groundwater, to evaluate the environmental impacts of agricultural activities and policies by qualifying the environmental levels of a nation. Status indicators were calculated according to the agricultural water quality standards of OECD and Korea, and their trends were analyzed over time. Particularly, nitrate ($NO_3{^-}$) status indicators of ground water in 2013 were significantly lower than the ones in 2000. Overall, the water quality indicators of surface water in 2013 were higher than the ones in 2012, except for pH and DO. The groundwater quality indicators in 2013 were lower than those of previous years. The optimal management indicators were calculated to assess agricultural surface water and groundwater quality. The findings of this study indicated that the state indicators could play a significant role to establish policies and procedures for managing and conserving water resources. This study also discussed water pollution caused by agricultural and industrial effluents.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.25 no.2
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• pp.11-20
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• 2019

Background: The purpose of this study was to investigate the immediate effect of thoracic self mobilization on balance and gait of acute stroke patients. Methods: Patients (n=10) with acute stroke applied to thoracic self mobilization. There are two thoracic self mobilization of both extension and rotation. Each thoracic self mobilization was performed ten times per direction in a total of three sets and the total time required for two thoracic self mobilization was twenty minutes. The break time between sets was one minute. Balance ability was measured using the timed up and go test and the five times sit to stand test for patients. The 10 meter walk test and the functional gait assessment were used for measurement of gait ability for patients. Results: Significant improvements were observed on balance ability (p<.05) and gait ability (p<.05). Conclusion: These results show that thoracic self mobilization is immediate effective on balance and gait ability. Thus, thoracic self mobilization will help recovery of balance and gait ability in acute stroke patients.

• 한국경영정보학회:학술대회논문집
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• 2007.06a
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• pp.503-508
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• 2007

In order to understand information system post-adoption phenomena, the expectation-confirmation model (ECM) was proposed. Past studies based on the ECM focus on a referent centered on the target IS being studied. The effect of this reference, captured through confirmation, has been strongly shown. However, the saliency of two additional reference effects, captured through self-image congruity and regret, has not been explored. In order to fill this knowledge gap, this paper attempts to develop a research model that extends the ECM by incorporating self-image congruity and regret as well as perceived enjoyment. For this extension, we synthesize the extant literature on continued IS use, self-image congruity, and regret. The analysis results tell us that self-image congruity plays a key role in forming two post-adoption beliefs, perceived usefulness and perceived enjoyment. It is also found that the absolute effect of regret on continuance intention is larger than those of other antecedents identified in IS. Overall, this study preliminarily confirms the saliency of self-image congruity and regret in post-adoption phenomena. Our study results is likely to help the IS community systematically address unexplored effects of self-image congruity and regret.

• The Korean Journal of Pesticide Science
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• v.19 no.2
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• pp.106-112
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• 2015

This experiment was carried out to investigate the best spray timing for the control of the bacterial shot hole with Bordeaux mixture (6-6) after wintering in the peach orchard. We sprayed Bordeaux mixture (6-6) on 'Mibaekdo', 'Yumyeong' and 'Cheonhong' of peach verities from late-March to mid-April in 2001, 2002 and 2014, and examined how much bacterial shot hole and chemical injure occurred. The infection rate of bacterial shot hole according to spray time was 10.2 to 11.7% at leaves, and 1.7 to 2.2% at fruits in 2002. And Efficacy of the Bordeaux mixture treatment for control of bacterial shot hole at full blooming time 21.2 to 30.4% at leaves, 1.7 to 4.4% at fruits in 2014. The chemical injure occurred slightly for one week hence. The fruit bearing rate was 20.7 to 29.8% at 'Mibaekdo', and 35.4 to 61.9% at 'Yumyeong' peach trees. When the spray at the time of blooming period by bordeaux mixture was investigated the control effect of bacterial shot hole disease. The infected leaves was better than 21 to 25% twice the quantity of finished products and bordeaux self-preparation about 28 to 30% base quantity of finished products, also the control efficacy was higher in infected fruits trends in bordeaux self-preparation method and twice the quantity of finished products.