• Journal of Korean Society of Steel Construction
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• v.23 no.5
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• pp.581-593
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• 2011

The underlying advantages of using thin-walled corrugatedwebs instead of plate girders with stiffeners are the elimination of instability problems associated with buckling of the thin-walled flat plate, and elimination of the need for transverse stiffeners, which alsoresults in economic advantages. This paper focuses on two aspects related to the structural design technique forsinusoidal corrugated web steel beams, and the optimum design of the beams using real-value genetic algorithms. The structural design process and design variables used in this optimization werecomposed with EN 1993-1-5, DASt-R015 standard and Pasternak et al. (2004), and the valid design capacity of shear buckling of the standards were compared. For the optimum structural design, the objective function, presented as the fullweight of the sinusoidal corrugated web beams, and the slenderness, member forces, and maximum deflection of the beam, were considered constraints. Finally, the simple beam under the uniform load was adopted as a numerical example, and the effective probability parameters of the genetic operators were considered to find the global minimum point.

• Journal of Korean Association for Spatial Structures
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• v.12 no.2
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• pp.18-23
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• 2012

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.7
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• pp.1180-1187
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• 2006

We Studied the method of structuring the sign system for pedestrians in the underground space by investigating and analyzing the sign system at Tae-jon Underground Commercial Area in Korea by 1) classifying the signs by types and comparing their numder for each type in sections, 2) classiflying the signs by the points of installation, types, functions and contents of information and comparing their numbers, 3) classifying the signs by their height and comparing by the points of installation, and 4) classifying the signs by their points of installation finding patterns. As a result, we found out that the current pedestrian signs in Tae-jon Underground Commercial Area could by classified into those installted with a certain regularity and those concentrated in at certain points. We also found out that there were many problems with the current signs system. The big gap of the type and numble of the signs, concentration of the signs at the gate (entrance), and the big gap of the function of the signs by their points of installation. And the gap of the signs by the number of installation is big between the North side and the South side. Most of signs concentrated in the South side show the problems of installation attached by the types and quantity of information. We suggest that type of information has consistency by posting of signs, at the same time, the necessary information should be offered in order for the pedestrians to easily recognize as they more in the Underground space.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.8
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• pp.423-432
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• 2016

Due to the increase in the number of transfer lines and ground level connections with mixed-use high-rise buildings, the Seoul Metro suffers from loaded signage fatigue because of the presence of too many signs. The purpose of this research is to propose ways of improving the wayfinding on the Seoul subway station by examining the signage and (applying the) universal design (UD) concept. A review of the literature explored five universal design components, viz. the accessibility, safety, equitability, perception, and aesthetics. The field investigation found that the ceiling and wall type and general information boards were high on the information hierarchy. The survey respondents merely perceived universal design concept, however, most needed principle. The IPA found that the signs should be appropriately laid out, spaced and located from the perspective of accessibility, and their unity and harmony were other aspects that could be improved while general information boards should include important landmarks outside. In conclusion, this study suggests that the universal design signage concept should be applied to every station and that specific stations should have a duly sign system.

• Proceedings of the KIPE Conference
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• 2008.06a
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• pp.607-609
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• 2008

본 논문에서는 태양광 발전 및 연료전지 시스템에서 사용되는 계통 연계형 인버터에 적용 가능한 새로운 전류제어기 설계방법을 제안한다. 제안된 상태궤환 전류제어기는 극점배치기법을 이용하여 주어진 시스템 요구사항에 따른 체계적인 제어기설계가 가능하며, 계통 전압과 동상을 가지도록 계통 주입전류를 제어한다. 이에 따라, 사인입력 기준전압을 추적할 수 있는 상태궤환 제어 알고리즘을 인버터의 대신호 평균 모델을 이용하여 설계하고, 200W급 계통 연계형 2단 구조 태양광 발전 전력변환 축소 시스템의 실험을 통하여 그 성능을 검증한다.

• Proceedings of the Korean Magnestics Society Conference
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• 2009.12a
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• pp.142-143
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• 2009

• Journal of Korean Society of Steel Construction
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• v.24 no.6
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• pp.671-682
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• 2012

The use of sinusoidal corrugated web girder for the box-type girders and gable steel main frames has recently been increasing very much. The reasons are that the thin web of the girder affords a significant weight reduction compared with rolled beam and welded built-up girder, and that corrugation prevents the buckling failure of the web. Improvements of the automatic fabrication process makes mass production of the corrugated web and unit possible, and applications of this girder have been extended considerably. Thus, the research for the optimum design processer considering the production data is needed practically. For doing this research, we develope the discrete optimum structural design program in consideration of production list data for the research, and the program apply to the single girder under the uniform load and the concentrated load as numerical example. We consider objective function as minimum weight of the girder, and use slenderness ratio, stress of flanges and corrugated web, and the girder deflection as the constraint functions. And also the Genetic Algorithms is adopted to search the global minimum point by using the production list as a discrete design variable. Finally, to verify the optimality of the design, we conduct a comparison of the results of the discrete optimum design with those of the continuous one, and also analyze the characteristics of the optimum cross-section.

• The Transactions of the Korea Information Processing Society
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• v.6 no.4
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• pp.1112-1119
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• 1999

Digital watermarking is to embed imperceptible mark into image, video, audio and text data to prevent the illegal copy of multimedia data, arbitrary modification, and also illegal sales of the copes without agreement of copyright ownership. The DCT(discrete Cosine Transforms) transforms of original image is conducted in this research and these DCT coefficients are expanded by Fourier series expansion algorithm. In order to embed the imperceptible and robust watermark, the Fourier coefficients(lower frequency coefficients) can be calculated using sine and cosine function which have a complete orthogonal basis function, and the watermark is embedded into these coefficients, In the experiment, we can show robustness with respect to image distortion such as JPEG compression, bluring and adding uniform noise. The correlation coefficient are in the range from 0.5467 to 0.9507.

• Membrane Journal
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• v.25 no.4
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• pp.320-326
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• 2015

In this study, permeation experiments were carried out using the symmetric and asymmetric sinusoidal flux continuous operation (SFCO) modes for the submerged flat sheet membrane in the 0.5 wt% emulsion type cutting oil solution. The effective area and nominal pore size of the used microfiltration membrane were $0.02m^2$ and $0.15{\mu}m$, respectively. The emulsion cutting oil was rejected over 99% based on turbidity. Transmembrane pressure increased lower as the aeration rates increased. The symmetric SFCO mode was a little more effective than the symmetric SFCO mode in low permeate flux between 10 and $15L/m^2{\cdot}h$. However, the symmetric SFCO mode was shown very effectively in high permeate flux between 25 and $30L/m^2{\cdot}h$.

• Journal of The Korea Institute of Healthcare Architecture
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• v.5 no.8
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• pp.23-32
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• 1999

It's difficult to understand the interior of complex facilities such as general hospital, because interior spatial composition in hospital tends to be focused. So it is important to find out how people understand the structure of interior spaces. Therefore, this study aims to analyze spatial information from the sign data concerned with sighting and thinking of subject who make way-finding as a first-time visit from an entrance to a goal by way-finding method and clarify plan of sign in two general hospital which have typical plans in Korea.; One is corridor type and the other is hall type.