• Journal of the Korean earth science society
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• v.30 no.5
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• pp.671-681
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• 2009

In the equilibrium theory of tides by Newton, tide on the Earth is a phenomenon driven by differential gravity contributed both by the Sun and the Moon. Due to the direct link of the generic tidal effect to the oceanic tides, college students in the earth science education department are exposed to this theory through oceanography lectures as well as astronomy lectures. Common oceanography textbooks adopt a non-inertial reference frame fixed to the Earth in which the fictitious, centrifugal force appears. This has a potential risk to provide misconceptions among students in various aspects including the followings: 1) this is how Newton originally derived the equilibrium theory of tides, and 2) the tide is a phenomenon appearing only in rotating systems. We show that in astronomy, a much simpler description, which employs the inertial frame, is generally used to explain tides and thus causes less confusion. We argue that the description used in astronomy is preferable both in the viewpoints of simplicity and ease of interpretation. Moreover, on a historical basis, an inertial frame was adopted by Newton in Principia to explain tides. Thus, the description used in astronomy is consistent with Newton's original approach. We also present various astrophysical tides which do not comply with the concept of centrifugal force in general. We therefore argue that the description used in oceanography should be compensated by that in astronomy, due to its complexity, historical inconsistency and limited applicability.

• The Mathematical Education
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• v.29 no.1
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• pp.63-68
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• 1990

Let M be a differentiable manifold, TM its tangent bundle and FM its frame bundle. The theory of complete lifts and Horizontal lifts to FM of vector fields on M ahs been studied by many authors. Tn this paper, vertical lifts of functions vector fields md 1-forms on M to FM are studied.

• Journal of the Korean Society of Safety
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• v.29 no.3
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• pp.64-71
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• 2014

The generalized tangential stiffness matrix of semi-rigid frame element with shear deformations based on Haringx's shear theory is newly derived and compared with the previous study based on Engesser's shear theory. Also, linearized elastic and geometric stiffness matrices are newly presented from the exact tangential stiffness matrix. In oder to obtain the inelastic system buckling load of shear flexible semi-rigid frame structure, the Ef method by tangential modulus theory is adopted and the FE analysis programs are developed. Finally, the shear and semi-rigid effects of system bucking are investigated by two numerical examples.

• Fashion & Textile Research Journal
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• v.7 no.6
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• pp.585-593
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• 2005

Diverse and complicated trends of fashion design which were initiated at the latter part of the 20th century have been evolving in the cultural framework of Postmodernism. At this point of time, Poststructuralism, with its aims to interpret and understand modern fashion design, is a new system of thinking that reveals the contradictory aspects of rationalistic Western philosophy and accepts uncertainty and disorder as they exist. The main purpose of this study is to examine the various theoretic systems and characteristic concepts of Poststructuralism, and supply a new cognizance frame to understand the processes of fashion design with free and varied notions of deconstruction and generation, in place of the former systematic and consistent interpretation of meaning. Concerning fashion design, analysis of theories and analysis of contents. By probing and examining deconstruction theory, 'I'-other theory, textual theory, and nomadic thinking, the concepts of cognizance are classified into Nonboundariness, Otherness, and Textualism. The theoretic foundation for this analysis and classification is supplied by Derrida's deconstructional philosophy, Lacan's mental analysis, Bartes's textual theory, Deleuze's change and generation theory, together with other theories of Poststructuralism. In analysis of theories, a cognizance frame is proposed that can categorize the concepts, derived from various theories of Poststructuralism, as traits expressed in fashion design.

• Proceedings of the KIEE Conference
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• 1987.07b
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• pp.1042-1045
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• 1987

This paper describes a User Guidance System that extracts Conceptual Structure from the input sentence by use of en theory and performs Question Answering in Teletex Manual domain. It uses Frame typed knowledge base and Frame recognizer as Link procedure between CD structure and Frame controller.

• Bulletin of the Korean Mathematical Society
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• v.49 no.3
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• pp.635-645
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• 2012

In this study, we investigate the curvature functions of ruled surface with lightlike ruling for a null curve with Cartan frame in Minkowski 3-space. Also, we give relations between the curvature functions of this ruled surface and curvature functions of central normal surface. Finally, we use the curvature theory of the ruled surface for determine differential properties of a robot end-effector motion.

• Magazine of the Korean Society of Agricultural Engineers
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• v.36 no.1
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• pp.116-127
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• 1994

A reliability analysis model for the frame structure which grafts the discretized ideal plastic method to the stochastic finite element method is introduced. The proposed method simmulates realistically the sequencial occurrence of plastic hinges and yields the probability of failure directly from the geometrical and material properties of a frame structure. The presented method can also take into account the uncertainties inherent in loads and resisten- ces through the stochastic finite element technique. The analysis results are compared with those of the Monte Carlo Simmulation, the Bound Theory, and the fs-unzipping method, and show good agreement.

• Journal of Power Electronics
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• v.8 no.1
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• pp.91-100
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• 2008

The d-q harmonic detecting algorithms are dominant methods to generate current references for active power filters (APF). They are often implemented in the synchronous frame and time domain. This paper researches the frequency characteristics of d-q synchronous transformations, which are closely related to the analysis and design issues of control system. Intuitively, the synchronous transformation is explained with amplitude modulation (AM) in this paper. Then, the synchronous filter is proven to be a time-invariant and linear system, and its transfer function matrix is derived in the stationary frames. These frequency-domain models imply that the synchronous transformation has an equivalent effect of frequency transformation. It is because of this feature, the d-q method achieves band-pass characteristics with the low pass filters in the synchronous frame at run time. To simplify these analytical models, an instantaneous positive-negative sequence frame is proposed as expansion of traditional symmetrical components theory. Furthermore, the synchronous filter is compared with the traditional bind-pass filters based on these frequency-domain analytical models. The d-q harmonic detection methods are also improved to eliminate the inherent coupling effect of synchronous transformation. Typical examples are given to verify previous analysis and comparison. Simulation and experimental results are also provided for verification.

• Smart Structures and Systems
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• v.5 no.6
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• pp.613-632
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• 2009

The present paper is concerned with the design of a proper patch actuator network in order to track a desired displacement of the sidewalls of a one-storey frame structure; both, for the static and the dynamic case. Weights for each patch of the actuator network found in our previous work were based on beam theory; in the present paper a refinement of these weights by modeling the sidewalls of the frame structure as thin plates is presented. For the sake of calculating the refined weights approximate solutions of the plate equations are calculated by an extended Galerkin method. The solutions based on the analytical plate model are compared with three-dimensional Finite Element results computed in the commercially available code ANSYS. The patch actuator network is put into practice by means of four piezoelectric patches attached to each of the two sidewalls of the frame structures, to which electric voltages proportional to the analytically refined patch weights are applied. Analytical and numerical results coincide very well over a broad frequency range.

• Korean Journal of Adult Nursing
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• v.14 no.2
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• pp.244-255
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• 2002

Purpose: This study was to understand to the nursing theory frame contained in the traditional philosophy and western nursing theory for the theory development fit for Korean people and to identified the strategy for nursing theory development. Method: To perform this study various relevant texts-western, eastern, classical and contemporary were reviewed. Result: The metaparadigm of the nursing in western considers four major factors-Human being, Environment, Health and Nursing. In Korea, the metaparadigm of nursing considers three major factors-Universe, Human being (body, life, health, disease) and Nursing. The key strategy for establishing comprehensive nursing theory which combines both western and eastern is to study the nursing literature based on eastern and western philosophy. Theorists should study the life and culture of the specific nation in order to understand the essence of the thoughts and psychology of the patients and to investigate the phenomena, which will be the foundation of theory development. Conclusion: Western nursing theory must be utilized to provide practical framework for the development of nursing theory, and practical approach is necessary for combining western and eastern theory.