• Journal of the Korean Mathematical Society
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• v.48 no.6
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• pp.1101-1123
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• 2011

Numerical schemes are routinely used to predict the behavior of continuous dynamical systems. All such schemes transform flows into maps, which can possess dynamical behavior deviating from their continuous counterparts. Here the common bifurcations of scalar dynamical systems are transformed under a class of algorithms known as linearized one-point collocation methods. Through the use of normal forms, we prove that each such bifurcation in an originating flow gives rise to an exactly corresponding one in its discretization. The conditions for spurious period doubling behavior under this class of algorithm are derived. We discuss the global behavioral consequences of a singular set induced by the discretizing methods, including loss of monotonicity of solutions, intermittency, and distortion of attractor basins.

• Earthquakes and Structures
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• v.6 no.1
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• pp.45-69
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• 2014

The 2009 L'Aquila, Italy earthquake shook a high density area causing a wide spectrum of damage to reinforced concrete with infill buildings, one of the most common building types used in Italy. The earthquake has proven to be a "full-scale" laboratory to further understand building performance. This paper presents the first results of a joint research effort between the University of Bologna and Degenkolb Engineers, aimed at investigating the seismic behavior of an infilled frame building that collapsed during the earthquake. State-of-the-practice techniques were implemented as a way to determine the reliability of these modeling techniques in anticipating the observed building performance. The main results indicate that: (i) the state-of-the-practice techniques are able to predict the observed behavior of the buildings; (ii) the masonry infills have a great influence on the behavior of the building in terms of stiffness, strength and global ductility.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1992.04a
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• pp.65-70
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• 1992

This study deals with the finite element analysis of the monotonic behavior of reinforced concrete beams and beam-column joint subassemblages. It is assumed that the behavior of these members can be discribed by a plane stress field. Concrete and reinforcing steel are represented by separate material models which are combined together with a model of the interaction between reinforcing bar and concrete through bond-slip to discribe the behavior of the composite reinforced concrete material. To discribe the concrete behavior, a nonlinear orthotropic model is adopted and the crack is discribed by a system of orthogonal cracks, which are rotating as the principal strain directions are changed. A smeared finite element model based on the fracture mechanics principles are used to overcome the numerical defect according to the finite element mesh size. Finally, correlation studies between analytical and experimental results and several parameter studies are conducted with the objective to estabilish the validity of the proposed model and identify the significance of various effects on the local and global response of reinforced concrete members.

• Korean Journal of Child Studies
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• v.26 no.6
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• pp.17-28
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• 2005

To understand further the differences in the distribution of attachment classifications assigned to 12-15 month old infant raised in Korea(N=85) and the U.S.(N=104), detailed analyses of maternal and infant behavior during the Strange Situation was undertaken. Indices of infants' attachment behavior with their mothers and distress during separations were rated. The percentage of Korean infants classified as secure versus insecure mirrored the global distribution, however, fewer Korean babies were classified as avoidant, As predicted, secure Korean babies were less likely than secure U.S. babies to approach their mothers, maintain contact or show resistant behavior and more often displayed distress during the second separation from their mother. Resistant Korean babies, however, did not significantly differ from resistant U.S. babies with respect to their attachment behavior but more often displayed distress when left with a stranger. These findings are discussed with respect to cultural differences in caregiving.

• Korean Medical Education Review
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• v.20 no.2
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• pp.78-90
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• 2018

Recently, unprofessional behavior by physicians and misconduct by medical students have led to increased public concern over medical professionalism. Many studies have been conducted to explore strategies that reinforce professionalism education and prevent misconduct in medical students. However, most studies focused on defining the medical professionalism and its conceptual components. In this study, we conducted a conceptual analysis based on the literature review to categorize issues of unprofessional behavior, and identified doctors' indifference to self and others as the reason for the unprofessional behavior. In this regard, self-reflection provides a practical tool to overcome such indifference. We suggest 'education and evaluation based on self-reflection and reflective practices' as the effective strategies to enhance the professionalism in medical students.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1407-1412
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• 2003

In MEMS devices, packaging induced stress or stress induced structure deformation become increasing concerns since it directly affects the performance of the device. In this paper, deformation behavior of MEMS gyroscope package subjected to temparature change is investigated using high-sensitivity $Moir{\acute{e}}$ interferometry. Using the real-time $Moir{\acute{e}}$ setup, fringe patterns are recorded and analyzed at several temperatures. Temperature dependent analyses of warpages and extensions/contractions of the package are presented. Linear elastic behavior is documented in the temperature region of room temperature to $125^{\circ}C$. Analysis of the package reveals that global bending occurs due to the mismatch of thermal expansion coefficient between the chip, the molding compond and the PCB.

• Korean Management Science Review
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• v.33 no.2
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• pp.117-131
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• 2016

This study introduces the concepts on the phase-shifting phenomenon of financial markets, which was firstly used in econophysics area and explains how the phase-shifting behavior is studied in the fields of business management and finance. Specifically, we explain how the phases of financial markets are extremely changed under some external conditions, do an extensive literature review, and carry out case studies focusing on the 3 major financial crisis events including the 87 October crash, 97 Asian financial crisis, and 2007 global financial crisis. We also empirically examine the phase-shifting behavior of the Korean ELW products that has a similar payoff structure to the KOSPI200 options.

• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 1996.10a
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• pp.323-326
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• 1996

In this paper, we propose a new method of the communication system for cooperative behavior and control in a collective autonomous mobile robots. A communication function among the collective robots is essential to intelligent cooperation. In general, global communication is effective for small number of robots. However when the number of robot goes on increasing, this becomes difficult to be realized because of limited communication capacity and increasing amount of information to handle. And also the problems such as communication interference and improper message transmission occur. So we propose local communication system based on infrared sensor to realize the cooperative behavior and control as the solution of above problem. It is possible to prevent overflow of information and exchange of complex information by combining communicate a specific robot. At last we verify the effectiveness of the proposed communication system from example of cooperative behavior.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 1999.10a
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• pp.396-403
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• 1999

This experimental study investigates the hysterestic behavior of traditional timber frames subjected to lateral loads. Prototype frames for this study were selected from one of typical national treasures for timber structures in Korea. For simplicity roof structures and braket systems were excluded from specimens and the joint behavior of beam-to-column system were presumed to have crucial effect on their global behavior. The experimental observation showed stiffness degradation and slip after experiencing initial yield and the first cycle at a new larger displacement due to inherent gaps in traditional timber connection and gradual indentation of interfaces, The cyclic behaviors of all specimens were similar to those os modern timber frames with bolt and nail connections. Additional structural members such as an upper beam and clay-filled wall increased the initial stiffness strength and energy dissipation. It is expected that collapse of Korean traditional timber frames under lateral load is mainly caused from P-$\Delta$ effects rather than local member failure.

• International Journal of Advanced Culture Technology
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• v.7 no.3
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• pp.86-91
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• 2019

The goal of this study is to identify how different types of messages can contribute to the effectiveness of social media in healthier dietary behavior. The sample consisted of 160 participants who use social media and participants were randomly assigned to one of the four experimental conditions. The study shows that a positively framed message paired with a health focused message and a negatively framed message paired with a body image focused message exhibit a positive eWOM and message perception. This research offers direction for development of appropriate message types to improve social media effectiveness. Social media marketers and advertisers can develop social media content on healthier dietary behavior.