• Journal of The Korean Digital Architecture Interior Association
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• v.2 no.1
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• pp.45-51
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• 2002

The masonry structure has been widely used as the dwelling house structure in our country for a long time. The masonry structure is weak in the lateral forces such as strong wind and earthquake. But there is no regulation for it in the domestic aseismic design codes. The purpose of this study is to suggest a simple design method of un-reinforced masonry wall.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.1
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• pp.84.1-84.1
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• 2019

722 open clusters in the Sim open cluster catalogue show the outermost structure of open clusters. The catalogue is based on the proper motion and parallax of the stars. These results reveal the hidden structures of weak membership signals in the field star contamination. It contains the tidal tails, flattened structure along the galactic plane, interacting double clusters and very poor and spread clusters. We will show these interesting structures.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.35.4-35.4
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• 2019

Understanding the interplay between galaxies and dark matter in the universe is one of key challenges in modern astrophysics. This provides an important test of structure formation scenarios and cosmological models. I discuss three aspects of this test: (1) comparing the matter distribution from galaxy redshift surveys with that from weak-lensing surveys, (2) statistical comparison of large-scale structures between observations and cosmological simulations, and (3) multi-wavelength study of galaxies. These tests underscore the importance of combining photometric and spectroscopic surveys in observations along with cosmological simulations for exploring and understanding the structure formation.

• International Journal of Fluid Machinery and Systems
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• v.2 no.3
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• pp.197-205
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• 2009

Since large-scale commercial wind turbine generator systems such as MW-class wind turbines are becoming widely operated, the vibration and distortion of the blade are becoming larger and larger. Therefore the soft structure design instead of the solid-design is one of the important concepts to reduce the structural load and the cost of the wind turbine rotors. The objectives of the study are development of the fluid-structure coupled analysis code and evaluation of soft rotor-blade design to reduce the unsteady structural blade load. In this paper, fluid-structure coupled analysis for the HAWT rotor blade is performed by free wake panel method coupled with hinge-spring blade model for the flapwise blade motion. In the model, the continuous deflection of the rotor blade is represented by flapping angle of the hinge with one degree of freedom. The calculation results are evaluated by comparison with the database of the NREL unsteady aerodynamic experiment. In the analysis the unsteady flapwise moments in yawed inflow conditions are compared for the blades with different flapwise eigen frequencies.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.7 s.172
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• pp.146-154
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• 2005

Recently, the high-speed and intelligence technology of machine tools are developed for the high efficiency of productivity Under the operating condition from the high-speed of machine tools, the various failure modes can occur in core units of manufacturing system. Therefore it is for the reliability concept of machine tool to be required in a design level. And the above-stated technology must be accommodated in the feeding and spindle subsystem, etc those are the core units of machine tools. In this study, we are developed the test-bed of sliding cover (C-plate) in order to evaluating reliability and estimating failure modes of feeding subsystem under operating conditions. The reliability experiment using the developed test-bed and the additional structural analysis executed on single and double structure. We found out the weak parts of sliding cover and were able to predict a life cycle from the experiment results. In this study, we propose the new C-plate model with double link structure to apply the high-speed machine tool in the fundamental guideline.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.24-25
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• 2011

Molecular self-assembly has several advantages over other nanofabrication methods. Molecular building blocks ensure ultrafine pattern precision, parallel structure formation allows for mass production and a variety of three-dimensional structures are available for fabricating complex structures. Nevertheless, the molecular interaction for self-assembly generally relies on weak forces such as van der Waals force, hydrogen bonding, or hydrophobic interaction. Due to the weak interaction, the structure formation is usually slow and the degree of ordering is low in a self-assembled structure. To promote self-assembly, directed assembly methods employing prepatterned substrates or external fields have been developed and gathered a great deal of technological attention as a next generation nanofabrication process. In this presentation a variety of directed assembly methods for soft nanomaterials including block copolymers, peptides and carbon nanomaterials will be introduced. Block copolymers are representative self-assembling materials extensively utilized in nanofabrication. In contrast to colloid assembly or anodized metal oxides, various shapes of nanostructures, including lines or interconnected networks, can be generated with a precise tunability over their shape and size. Applying prepatterned substrates$^{1,2}$ or introducing thickness modulation$^3$ to block copolymer thin films allowed for the control over the orientational and positional orderings of self-assembled structures. The nanofabrication processes for metals, semiconductors$^4$, carbon nanotubes$^{5,6}$, and graphene$^{6,7}$ templating block copolymer self-assembly will be presented.

• Journal of Korea Trade
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• v.23 no.3
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• pp.105-117
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• 2019

Purpose - Underdog positioning is often used to evoke a positive attitude when interacting with consumers. However, little research has been conducted on the market competition structure and innovation contexts in which underdog positioning produces the most impact. This research aims to investigate unexplored boundary conditions of underdog positioning and addresses two issues: market structures (oligopoly vs monopolistic competition) and perceived firm innovativeness (PFI). Design/methodology - Two one-way ANOVA designs (market structures: monopolistic competitions vs. oligopoly; perceived frim innovativeness: strong vs. weak) were randomly assigned to 297 graduate and undergraduate students (52 % female) majoring in business. Study 1 examined the effect of underdog positioning on consumer attitudes in the different market structures. Study 2 investigated the relationship between underdog effect and consumer attitudes through viewing conditions that varied in PFI. Findings - Drawing on the results of the study, the authors conclude that underdog positioning is effective to generate more positive consumer attitudes when employed in the market structure of monopolistic competition rather than oligopoly. Moreover, both underdog and top dog positioning are likely to generate more positive consumer attitudes when accompanied with strong PFI than weak PFI. Originality/value -This is the first study to distinguish between monopolistic competition and oligopoly market structures with underdog positioning as well as to demonstrate a positive effect of PFI, regardless of the type of brand narratives.

• Korean Journal of Cognitive Science
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• v.19 no.2
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• pp.205-222
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• 2008

This study investigated scope relations between quantifier and focus which are represented in quantified sentences. In the sentence which has both strong quantifier and weak quantifier, one of them has a wide scope and a presuppositional reading, and the other which has a narrow one is interpreted non-presuppositionally. In Korean, when a weak quantifier is separated from VP in surface representation, whether it is a subject or an object, it has only a presuppositional reading. Therefore, there is no scope ambiguity in that sentence. However, when weak quantifier which is an object of transitive verb or a subject of transitive verb is sensitive to focus, it is available to non-presuppositional reading, so that the sentence seems to be ambiguous. Once even weak quantifier out of VP in the Surface structure is focused, it becomes to be in the scope of focus (focal phrase) which is formed in Logical form by a focus projection. And this scope of focus corresponds to a nuclear scope. That is to say, focus operates on the weak quantifier to be interpreted non-presuppositionally in a nuclear scope.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.125.1-125.1
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• 2012

The wave number 4 (wave-4) and wave number 3 (wave-3) longitudinal structures in the thermospheric neutral mass density are understood as tidal structures driven by diurnal eastward-propagating zonal wave number 3 (DE3) and wave number 2 (DE2) tides, respectively. However, those structures have been identified using data from limited time periods, and the consistency and recurrence of those structures have not yet been examined using long-term observation data. We examine the persistence of those structures by analyzing the neutral mass density data for the years 2001-2008 taken by the CHAllenging Minisatellite Payload (CHAMP) satellite. During years of low solar activity, the amplitude of the wave-4 structure is pronounced during August and September, and the wave-4 phase shows a consistent eastward phase progression of $90^{\circ}$ within 24 h local time in different months and years. During years of high solar activity, the wave-4 amplitude is small and does not show a distinctive annual pattern, but the tendency of the eastward phase shift at a rate of $90^{\circ}$/24 h exists. Thus the DE3 signature in the wave-4 structure is considered as a persistent feature. The wave-3 structure is a weak feature in most months and years. The amplitude and phase of the wave-3 structure do not show a notable solar cycle dependence. Among the contributing tidal modes to the wave-3 structure, the DE2 amplitude is most pronounced. This result may suggest that the DE2 signature, although it is a weak signature, is a perceivable persistent feature in the thermosphere.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.4
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• pp.328-333
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• 2006

In this paper, we developed a pressure measurement apparatus with the parallel structure to improve the measurement efficiency of pressure sensors by reducing the measurement time of pressure. The developed system has two parallel positions for loading Silicon pressure sensor and has a dual valve structure. The semiconductor pressure sensors prepared by Copal Electronics were used to confirm the performance of the developed measurement system. Two stage differential amplifier circuit was employed to amplify the weak output signal and the amplified output signal was improved utilizing a low-pass filter. New apparatus shows the measurement time of pressure two times shorter than that of conventional one with the serial structure, while both structures show the similar linear output versus pressure characteristics.