• Kyungpook Mathematical Journal
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• v.55 no.3
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• pp.641-652
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• 2015

In this paper we study the problem of normal families of meromorphic functions concerning shared values. Let F be a family of meromorphic functions in the plane domain $D{\subseteq}{\mathbb{C}}$ and n, k be two positive integers such that $n{\geq}k+1$, and let a, b be two finite complex constants such that $a{\neq}0$. Suppose that (1) $f+a(f^{(k)})^n$ and $g+a(g^{(k)})^n$ share b in D for every pair of functions f, $g{\in}F$; (2) All zeros of f have multiplicity at least k + 2 and all poles of f have multiplicity at least 2 for each $f{\in}F$ in D; (3) Zeros of $f^{(k)}(z)$ are not the b points of f(z) for each $f{\in}F$ in D. Then F is normal in D. And some examples are provided to show the result is sharp.

• Economic and Environmental Geology
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• v.22 no.1
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• pp.65-80
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• 1989

Strongly weathered granitic rocks are widely distributed in the south-eastern part of the Ganghwa island. Kaolinite developed during intense weathering on this granitic rocks have been studied mineralogically and chemically. Various weathering indexes were ca1culated on the basis of oxide. Those indexes are slightly varied with depth. It shows that the percentages of $Al_2O_3$ increase but that of $CaO+Na_2O+K_2O$ decrease as the weathering progress. These results indicate that day minerals, mainly kaolinite with the appreciable amount of halloysite, were formed by the weathering of feldspars in the granitic rocks. X-ray diffraction, differential thermal analysis, infrared spectrometry and electron microscopy were used to characterize and estimate crystallinity of the kaolinite. Generally, Kaolinite shows a less sharp basal reflection and relatively low dehydroxylation temperature, indicating disordered kaolinite. They usually occur aggregates as a vermicular kaolinites showing loose basal plane stacking arrangement.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.11
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• pp.180-188
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• 1998

Z-map is a special form of discrete nonparametric representation in which the height values at grid points on the xy-plane are stored as a 2D array z[i.j]. While z-map is the simplest form of representing sculptured surfaces and it is the most versatile scheme for modeling nonparametric objects, its practical application in industry (eg, tool-path generation) aroused much controversy over its weaknesses ; accuracy, singularity (eg, vertical wall), and some excessive storage needs. Although z-map has such limitations, much research on the application of z-map can be found in various articles. However, research on the systematic analysis of sculptured surface shape representation via z-map model is rather rare. Presented in this paper are the following: shape modeling power of the simple z-map model, exact (within tolerance) B-map representation of sculptured surfaces which have some feature-shapes such as vertical-walls and real sharp-edges by adopting some complementary B-map models, and some application examples.

• International Journal of Advanced Culture Technology
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• v.9 no.1
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• pp.22-27
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• 2021

Morphology of contemporary city streets is composed of overlapping infrastructures corresponding to the new street within the established organization, contemporary system, future circumstance, and population. As well, two overlaid organizations and morphological, historical, social and physical development lead to sharp acute algle(triangular) site, and the architecture in this site has a restriction on the availability of the internal space and the external design due to outside shape sharpness. We want to have a positive effect on the internal and external design of the architecture in the future by categorization of the shape and processing characteristics of the acute angle corner of the trilateral site. The characteristics and design categorization shown in this case study are as follows. Constitution a unique and independent form, lead streets and shape a exclusive image of the landscape, alleviate sharpness by configuring a acute angle point as a plane, use void to give reserve character, replace roundness for companionability to induce ambience in the road, embrace the characteristics of the site and create internal spaces and functions, emphasize the characteristics of each stairs, retain of uniqueness and highlight the characteristics of a vertical elements.

• Educational Technology International
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• v.23 no.1
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• pp.1-39
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• 2022

We study emotion regulation in a distant CABLe (Collaborative Argumentation Based-Learning) setting at university. We analyze how students achieve the group task of synthesizing the literature on a topic through scientific argumentation on the institutional Moodle's forum. Distinguishing anticipatory from reactive emotional regulation shows how essential it is to establish and maintain a constructive working climate in order to make the best out of disagreement both on social and cognitive planes. We operationalize the analysis of anticipatory emotional regulation through an analytical grid applied to the data of two groups of students facing similar disagreement. Thanks to sharp anticipatory regulation, group 1 solved the conflict both on the social and the cognitive plane, while group 2 had to call out for external regulation by the teacher, stuck in a cyclically resurfacing dispute. While the institutional digital environment did afford anticipatory emotional regulation, reactive emotional regulation rather occurred through complementary informal and synchronous communication tools. Based on these qualitative case studies, we draw recommendations for fostering distant CABLe at university.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.12
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• pp.72-80
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• 1995

Ultraprecision machining technology has been playing a rapidly increasing and important role in manufacturing. However, the physics of the micromachining process at very small depth of cut, which is typically 1 .mu. m or less is not well understool. Shear along the shear plane and friction at the rake face dominate in conventional machining range. But sliding along the flank face of the tool due to the elastic recovery of the workpiece material and the effects of plowing due to the large effective negative rake angle resultant from the tool edge radius may become important in micromachining range. This paper suggests an orthogonal cutting model considering the cutting edge radius and then quantifies the effect of plowing due to the large effective negative rake angle.

• Steel and Composite Structures
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• v.23 no.5
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• pp.571-583
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• 2017

A kind of accordion-web RBS connection, "Tubular Web RBS (TW-RBS)" connection is proposed in this research. TW-RBS is made by replacing a part of web with a tube at the desirable location of the beam plastic hinge. This paper presents first a numerical study under cyclic load using ABAQUS finite element software. A test specimen is used for calibration and comparison of numerical results. Obtained results indicated that TW-RBS would reduce contribution of the beam web to the whole moment strength and creates a ductile fuse far from components of the beam-to-column connection. Besides, TW-RBS connection can increase story drift capacity up to 9% in the case of shallow beams which is much more than those stipulated by the current seismic codes. Furthermore, the tubular web like corrugated sheet can improve both the out-of-plane stiffness of the beam longitudinal axis and the flange stability condition due to the smaller width to thickness ratio of the beam flange in the plastic hinge region. Thus, the tubular web in the plastic hinge region improves lateral-torsional buckling stability of the beam as just local buckling of the beam flange at the center of the reduced section was observed during the tests. Also change of direction of strain in arc shape of the tubular web section is smaller than the accordion webs with sharp corners therefore the tubular web provides a better condition in terms of low-cycle fatigue than other accordion web with sharp corners.

• Analyses & Alternatives
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• v.7 no.2
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• pp.35-77
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• 2023

This study aims to solve the entangled loop between demographic transition (DT) and economic growth by analyzing cross-country data. We undertake a national-level group analysis to verify the compressed transition of demographic variables over time. Assuming that the LA (latecomer advantage) on DT over time exists, we verify that the DT of the latecomer is compressed by providing a formal proof of LA on DT over income. As a DT has the double-kinked functions of income, we check them in multiple aspects: early maturation, leftward threshold, and steeper descent under a contour map and econometric methods. We find that the developing countries (the latecomer) have speedy DT (CDT, compressed DT) as well as speedy income such that DT of the latecomers starts at lower levels of income, lasts for a shorter period, and finishes at the earlier stage of economic development compared to that of developed countries (the early mover). To check the balance of DT, we classify countries into four groups of DT---balanced, slow, unilateral, and rapid transition countries. We identify that the main causes of rapid transition are due to the strong family planning programs of the government. Finally, we check the effect of latecomer's CDT on economic growth inversely: we undertake the simulation of the CDT effect on economic growth and the aging process for the latecomer. A worrying result is that the CDT of the latecomer shows a sharp upturn of the working-age population, followed by a sharp downturn in a short period. Compared to early-mover countries, the latecomer countries cannot buy more time to accommodate the workable population for the period of demographic bonus and prepare their aging societies for demographic onus. Thus, we conclude that CDT is not necessarily advantageous to developing countries. These outcomes of the latecomer's CDT can be re-interpreted as follows. Developing countries need power sources to pump up economic development, such as the following production factors: labor, physical and financial capital, and economic systems. As for labor, the properties of early maturation and leftward thresholds on DTs of the latecomer mean that demographic movement occurs at an unusually early stage of economic development; this is similar to a plane that leaks fuel before or just before take-off, with the result that it no longer flies higher or farther. What is worse, the property of steeper descent represents the falling speed of a plane so that it cannot be sustained at higher levels, and then plummets to all-time lows.

• The Journal of Information Technology
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• v.4 no.3
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• pp.77-86
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• 2001

In this paper, Electromagnetic scattering problem by a resistive strip grating with 2 dielectric layers on a ground plane according as resistivity of resistive strip, relative permittivity and thickness of dielectric layers, and incident angles of a electric wave is analyzed by applying the PMM (Point Matching Method) known as a numerical procedure. The scattered electromagnetic fields are expanded in a series of floquet mode functions. The boundary conditions are applied to obtain the unknown field coefficients and the resistive boundary condition is used for the relationship between the tangential electric field and the electric current density on the strip. According as the relative permittivity and the thickness of layers are increased, the values of the geometrically normalized reflected power have a high value and the values of strip width are moved toward a high value going from left to right. When the resistivity of this paper has a value of zero, the numerical results of the geometrically normalized reflected power show in good agreement with those by the PMM of existing paper. Then, the most energys of the sharp variation point in minimum values of the geometrically normalized reflected power are scattered in direction of the other angles except incident angle.

• Transactions of the Korean Society of Mechanical Engineers
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• v.12 no.6
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• pp.1399-1406
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• 1988

Flow behaviors of the open channel type flow with its geometric boundary conditions being similar to that of the Multi-Stage-Flash evaporator were studied qualitatively by measuring the velocity distribution. Without a baffle, the flow was in the shape of a simple submerged plane wall jet. At the downstream of this flow, the jet boundary made sharp curve toward the free surface ; this is because the entrainment of the ambient liquid is restricted by the free surface boundary, similar to the Coanda effect. According to the experimental results the level of the free surface appeared to be the most important parameter. The flow with a baffle was in much complicated shape ; especially the recirculating region at the downstream free surface was detected according to the experimental conditions imposed. Inlet liquid velocity, heights of the liquid level and the baffle, and the opening heights of sluice gate of the entrance were the most important parameters in the baffle flow.