• Journal of the Korean Mathematical Society
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• v.41 no.6
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• pp.1101-1114
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• 2004

We generalize a result of Dror Farjoun and Zabrodsky on the relationship between fixed point sets and homotopy fixed point sets, which is related to the generalized Sullivan Conjecture. As an application, we discuss extension problems considering actions on homogeneous spaces of p-compact groups.

• Bulletin of the Korean Mathematical Society
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• v.49 no.3
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• pp.655-667
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• 2012

In this paper, we deal with a critical point metric of the total scalar curvature on a compact manifold $M$. We prove that if the critical point metric has parallel Ricci tensor, then the manifold is isometric to a standard sphere. Moreover, we show that if an $n$-dimensional Riemannian manifold is a warped product, or has harmonic curvature with non-parallel Ricci tensor, then it cannot be a critical point metric.

• Kyungpook Mathematical Journal
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• v.54 no.3
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• pp.485-500
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• 2014

In this paper, we establish coupled fixed point theorems for mixed monotone mappings satisfying nonlinear contraction involving a pair of altering distance functions in ordered G-metric spaces. Via presented theorems we extend and generalize the results of Harjani et al. [J. Harjani, B. L$\acute{o}$pez and K. Sadarangani, Fixed point theorems for mixed monotone operators and applications to integral equations, Nonlinear Anal. 74 (2011) 1749-1760] and Choudhury and Maity [B.S. Choudhury and P. Maity, Coupled fixed point results in generalized metric spaces. Math. Comput. Model. 54 (2011), 73-79].

• Bulletin of the Korean Mathematical Society
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• v.37 no.1
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• pp.11-19
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• 2000

We give a new coincidence theorem for multimaps on generalized convex spaces and apply it to deduce s-saddle point and saddle point theorems.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.383-383
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• 2011

Generally, field emitters can be categorized into two types according to the emitter shape, one is a planar field emitter and the other is a point emitter. The planar field emitter is used for displays, flat lamps and signage boards. On the other hands, the point field emitter is expected to play a significant role in x-ray sources and electron beam sources. Such applications of the point field emitters, especially, need large emission current and high emission stability with a small electron beam size. A few reports announced point emitters made by carbon nanotubes (CNTs). However, they still have suffered from poor reproducibility and low emission current. Here, we demonstrated high performance CNT point emitters by attaching CNTs onto graphite rod. Graphite rod exhibited good electrical conductivity and chemical stability. In this method, the shape of the point emitter could be easily controlled by changing the length and diameter of the graphite rod. The CNT point emitter showed emission current over 1 mA at an applied electric field of 1.4 V/${\mu}m$. We consider that the stable emission performance is attributed to the stable contact between CNTs and graphite rod.

• Journal of Educational Research in Mathematics
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• v.26 no.4
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• pp.731-754
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• 2016

The purpose of the study is to identify the point of knowing. The point of knowing is the time, which indicates that 'knowing' occurs in the recognition process. To understand recognition process, the researchers analyzed the questions in units of lessons presented in elementary mathematics textbooks. The researchers analyzed the validity of the point of knowing and found out the basis of the point of knowing. The results are as follows. First, the point of knowing is time to expect to change from a leaner's 'not-knowing' to 'knowing'. Second, the point of knowing can be identified with the questions on textbooks to ask students to do practical action. Third, the point of knowing is closely related to instructional objective in a class. Fourth, in relation to subsidiary awareness and focal awareness, the point of knowing corresponds to focal awareness. Fifth, the point of knowing is equivalent to the inflection point at which personalization/contextualization is changed into depersonalization/decontextualization.

• Journal of IKEEE
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• v.17 no.3
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• pp.346-351
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• 2013

Low-cost and low-power are important requirements in mobile systems. Thus, when a floating-point arithmetic unit is needed, 24-bit floating-point format can be more useful than 32-bit floating-point format. However, a 24-bit floating-point arithmetic unit can be risky because it usually has lower accuracy than a 32-bit floating-point arithmetic unit. Consecutive floating-point operations are performed in 3D graphic processors. In this case, the verification of the floating-point operation accuracy is important. Among 3D graphic arithmetic operations, the floating-point division is one of the most difficult operations to satisfy the accuracy of $10^{-5}$ which is the required accuracy in OpenGL ES 3.0. No 24-bit floating-point divider, whose accuracy is algebraically verified, has been reported. In this paper, a 24-bit floating-point divider is analyzed and it is algebraically verified that its accuracy satisfies the OpenGL requirement.

• Korean Journal of Acupuncture
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• v.24 no.4
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• pp.47-54
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• 2007

Objection : A medicine which is patient-initiative and preventive is required in Korea, which is going to an aging society. On this, we started this study to make a new rule to diagnose and treat more definitely by linking traditional Oriental medicine to Sasang Constitional medicine, which thought to be suitable because of Sasang Constitional medicine has been valued on staying, diet and human's nature which means preventive medical propensity. Methods : On this study, we discriminated Sasang Constition of 161 students, who is in college of oriental medicine, Wonkwang university, by using QSCCII program; and in those students, we checked 30 volunteers's five vicera's Back-su point on riging and depression, tenderness reaction, and color reaction after cupping treatment. Results : As a result of study of riging and depression of five vicera's Back-su point, we could confirm that defecient organ's Back-su point were more depressed than excess organ in Seum-in, Taeeum-in, Soyang-in. As a result of study of tenderness reaction of five vicera's Back-su point, we could confirm that excess organ's Back-su point showed stronger tenderness reaction than defecient organ in Seum-in, Taeeum-in; and excess organ's Back-su point showed weaker tenderness reaction than defecient organ in Soyang-in. As a result of study of color reaction after cupping treatment of five vicera's Back-su point, we could confirm that excess organ's Back-su point showed stronger color reaction than defecient organ in Seum-in, Taeeum-in; and excess organ's Back-su point showed weaker color reaction than defecient organ in Soyang-in. Those data suggest that there are close correlation between Sasang Constition and on riging and depression, tenderness reaction, and color reaction after cupping treatment of five vicera's Back-su point in treditional Oriental medicine. Conclusions : From this study, we can make a new rule to differentiate Sasang Constition by clearfy a relation between Sasang Constition and five vicera's Back-su point; and with this rule, we could contribute to popularization and objectification of Sasang Constition medicine and further more, Oriental medicine by making a Sasang Constition diagnosis instrument. With this, a trait of Sasang Constition medicine that is preventive and valued on character of individuals will contribute to building a patient-initiative and preventive medical system and will expend the domain of Oriental medicine.

• Molecules and Cells
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• v.43 no.2
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• pp.182-187
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• 2020

When cells are stimulated by growth factors, they make a critical choice in early G₁ phase: proceed forward to S phase, remain in G₁, or revert to G₀ phase. Once the critical decision is made, cells execute a fixed program independently of extracellular signals. The specific stage at which the critical decision is made is called the restriction point or R-point. The existence of the R-point raises a major question: what is the nature of the molecular machinery that decides whether or not a cell in G₁ will continue to advance through the cell cycle or exit from the cell cycle? The R-point program is perturbed in nearly all cancer cells. Therefore, exploring the nature of the R-point decision-making machinery will provide insight into how cells consult extracellular signals and intracellular status to make an appropriate R-point decision, as well into the development of cancers. Recent studies have shown that expression of a number of immediate early genes is associated with the R-point decision, and that the decision-making program constitutes an oncogene surveillance mechanism. In this review, we briefly summarize recent findings regarding the mechanisms underlying the context-dependent R-point decision.

• The Journal of Korean Academy of Prosthodontics
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• v.35 no.2
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• pp.277-295
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• 1997

After clinical adjustment of dental casting restoration, re-polishing procedure is recommanded because the smooth gold sureface is lost. But there is the possibility to get more loose contact than that intended by loss of gold alloy according to the kinds of polishing materials and polishing time. Therefore in this study I polished type II gold alloy with 390gm force, 20,000rpm speed, and 8 kinds of gold alloy polishing materials, fabricated by 4 companies and then measured the amount of loss of gold alloy with Surfcorder SEF-30D and observed alloy surfaces polished by 3 brown rubber points with SEM. The amount of loss of gold alloys polished with 8 kinds of polishing materials and the degree of smoothness of gold alloys according to polishing time and polishing materials were compared. The following results were obtained : 1. When the amount of loss of gold alloys polished with 3 kinds of brown rubber point was compared, Alphalex brown point had the most amount of alloy loss, followed in decreasing order by Shofu brown point and Eveflex brown point. There was statistically significant difference in the amount of alloy loss according to polishing materials. 2. When the amount of loss of gold alloys polished with 5 kinds of green rubber point was compared, Shofu green point had the most amount of alloy loss, followed in decreasing order by Alphaflex green point, Dedeco green clasp polisher, and Eveflex green point. There was statistically significant difference in the amount of alloy loss according to polishing materials except Alphaflex green point and Dedeco green clasp polisher. 3. When the amount of loss of gold alloys polished with all kinds of rubber point was compared, there was no significant difference in Eveflex brown point, Alphaflex green point, and Dedeco green clasp polisher. 4. When average amount of alloy loss per 1 revolution by polishing materials was compared, Alphalex brown point had the greatest value as $0.329{\mu}m$ and Shofu supergreen point had the lowest value as $0.022{\mu}m$. 5. When the degree of sureface smoothness of gold alloy polished with 3 kinds of brown rubber point was compared, In Alphalex brown point surface roughness was completely lost after 20 seconds polishing time, in Shofu brown point 30 seconds, in Eveflex brown point 40 seconds. But in every gold alloys fine scratch formed by rubber points was observed. Based on the results of this study, as rubber polishing materials used in polishing of dental casting restoration after clinical adjustment influenced on the tightness of occlusal or proximal contact, we should make dental casting restoration with minimum error through careful laboratory procedure and form very smooth surface of restoration with tripoli and rouge after use of silicone polishing materials.