• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.16 no.9 s.114
• /
• pp.919-925
• /
• 2006

An accurate mathematical model for complex stiffness of the pneumatic spring would be necessary for an efficient design of a pneumatic spring used in vibration isolation tables for precision instruments such as optical devices or nano-scale equipments. A diaphragm, often employed for prevention of air leakage, plays a significant role of complex stiffness element as well as the pressurized air itself Therefore, effects of the diaphragm need to be included in the dynamic model for a more faithful description of dynamic behavior of pneumatic spring. But the complex stiffness of diaphragm is difficult to predict In an analytical way, since it is a rubber membrane of complicated shape in itself. Moreover, the diaphragm should be expandable in response to pressurization inside a chamber, which makes direct measurement of complex stiffness of diaphragm extremely difficult. In our earlier research, the complex stiffness of diaphragm was indirectly measured, which was just to eliminate the theoretical stiffness of pressurized air from the measured complex stiffness of the pneumatic spring. In order to reflect complex stiffness of inflated diaphragm on the total stiffness at the initial design or design improvement stage, however. it is required to be able to predict beforehand. In this paper, how to predict the complex stiffness of inflated rubber diaphragm by commercial FE codes (e.g. ABAQUS) will be discussed and the results will be compared with the indirectly measured values.

• 한국방재학회:학술대회논문집
• /
• 2007.02a
• /
• pp.538-541
• /
• 2007

In this study, the complex AAM permanent anchor was introduced and the design method for the complex AAM permanent anchor was showed by examining the relationship of the forces applied to the anchor, the ground failure, the loads inducing the tensile failure between the anchors, etc. In order to understand the behavioral characteristics of the complex AAM permanent anchor, the field pullout test was carried out, and the results obtained with the design method were compared with those of the field pullout test.

• Structural Engineering and Mechanics
• /
• v.45 no.1
• /
• pp.1-18
• /
• 2013

The typhoon wind characteristics designing for buildings or bridges located in complex terrain and typhoon prone region normally cannot be achieved by the very often few field measurement data, or by physical simulation in wind tunnel. This study proposes a numerical simulation procedure for predicting directional typhoon design wind speeds and profiles for sites over complex terrain by integrating typhoon wind field model, Monte Carlo simulation technique, CFD simulation and artificial neural networks (ANN). The site of Stonecutters Bridge in Hong Kong is chosen as a case study to examine the feasibility of the proposed numerical simulation procedure. Directional typhoon wind fields on the upstream of complex terrain are first generated by using typhoon wind field model together with Monte Carlo simulation method. Then, ANN for predicting directional typhoon wind field at the site are trained using representative directional typhoon wind fields for upstream and these at the site obtained from CFD simulation. Finally, based on the trained ANN model, thousands of directional typhoon wind fields for the site can be generated, and the directional design wind speeds by using extreme wind speed analysis and the directional averaged mean wind profiles can be produced for the site. The case study demonstrated that the proposed procedure is feasible and applicable, and that the effects of complex terrain on design typhoon wind speeds and wind profiles are significant.

• Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.248-252
• /
• 2015

Currently composite manufacturing process, such as linear friction welding plus NC machining, is the main method for the manufacturing and repairing of complex parts with integrated structure. Due to different datum position and inevitable distortion from different processes, it is important to ensure sufficient machining allowance for complex parts during the NC machining process. In this paper, a workpiece localization approach for machining allowance optimization of complex parts based on CMM inspection is developed. This technique concerns an alignment process to ensure sufficient stock allowance for the single parts as well as the whole integrated parts. The mathematical model of the constrained alignment is firstly established, and then the symmetric block solution strategy is proposed to solve the optimization model. Experiment result shows that the approach is appropriate and feasible to distribute the machining allowance for the single and whole parts for adaptive machining of complex parts.

• Journal of Institute of Control, Robotics and Systems
• /
• v.15 no.7
• /
• pp.671-674
• /
• 2009

Determining the Schur stability of a polynomial is one of fundamental steps in many engineering problems including digital control system design or digital filter design. Due to its importance a variety of techniques have been reported in the literature for checking the Schur stability of a given polynomial. However most of them focus on real polynomials, and few results are available for complex polynomials. This paper concerns the Schur stability of complex polynomials. A simplified Jury's table for real polynomials is extended to complex polynomials.

• Proceedings of the Korean Institute of Interior Design Conference
• /
• 2004.05a
• /
• pp.77-80
• /
• 2004

The Pinakothek der Moderne(Munich, 1996-2002, Stephan Braunfels) in planned to form the Museum Complex, with the 4th Pinakothek harmonized with Alte Pinakothek(Munich, 1826-36, L.von.Klenze) and The Neue Pinakothek(Munich, 1981, Alexander von Branca). The Purpose of this study is to find the design method of Pinakothek der Moderne for forming the Musuem Complex

• Korean Journal of Computational Design and Engineering
• /
• v.12 no.3
• /
• pp.209-219
• /
• 2007

Designing a complex system such as an LCD developing system becomes inefficient when many designers are involved and create their own parts even though they can be used repeatedly in other sections. Thus, this paper proposes a new design process that can maximize the number of common parts in complex system design by organizing the 3D design process. The proposed design process consists of 5 stages: analysis of design intention, definition of initial product structure, definition of skeleton model, sharing design intention with all assembles, control of correlation between components. The proposed design process can maximize common parts in design process, which results in shorter lead time, less production cost, and greater economic benefits.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.6
• /
• pp.85-92
• /
• 2018

This study was to confirm the effectiveness of crime prevention in an apartment complex environmentally designed for domestic crime prevention. The researchers surveyed 267 residents on the community, fear of crime, and crime victimization. They arrived at the following conclusions. The authorization complex received higher security satisfaction results than the unauthorized complex; residents were less afraid of crime and more active in the apartment complex community. These results differ from previous studies in that the fear of crime is not related to a crime victim experience and that the fear of crime is low when there are less households in the apartment complex. Therefore, effectiveness of crime prevention abroad should not be accepted in a domestic residential environment.

• Journal of the Architectural Institute of Korea Planning & Design
• /
• v.34 no.6
• /
• pp.135-142
• /
• 2018

A public pedestrian passage induces traffic into the apartment complex, and therefore, it requires the application of Crime Prevention Through Environmental Design(CPTED). This paper aims to analyze the conditions and to suggest the improvements of public pedestrian passages in apartment complexes, applying a 3-D approach from CPTED aspect. The first aspect is "Designation": 1)The linkage between the public pedestrian passages is weak, and their designated purpose becomes unclear. 2)When the designated purpose is not considered for each complex, the closure rate is high. 3)The closure rate of the "Through type" is high. It suggests that the pedestrian network should be built and vitalized at the local urban level. The second aspect is "Definition." The public pedestrian passage lacks a social, cultural, and legal definition and only has a passive physical definition. It suggests that a legal definition and specialized guildline be prepared. The third aspect is "Design": 1)Insufficient territoriality exists between the public pedestrian passage and the inside of the complex. Territoriality should be reinforced between the public pedestrian passage and the rest of the internal territory. 2)The landscaping adjacent to the public pedestrian passage lacks deliberation. Since this is where safety and privacy collide, detailed design and maintenance of the landscaping is required. 3)It lacks systematical crime prevention facilities and should compensate accordingly.

• Journal of the Korean Society of Systems Engineering
• /
• v.2 no.1
• /
• pp.37-41
• /
• 2006

The KSLV-I satellite launch vehicle will be launched in a space center currently under construction. The Space Center which is an advance post base of space development of Korea is located on Oenaro island in Kohung, South Cholla Province. A Ground Complex of the Space Center consists of an AC(Assembly Complex), a LC(Launch Complex), and a MCC(Mission Control Center). Assembly and test facilities are located in the AC in which stage assembly, integrated assembly, check-up, certification test, and pre-launch test are made effectively. A launch pad, fuel supply facilities, a launch control center and associated supporting facilities are located in the LC, and the MCC has control over the space center. These ground complex facilities have diverse forms of an interface with mechanical device, electric device, and etc. These should also provide optimum condition and performance during launch operation processes of the launch vehicle. This paper introduces the result of R&D for the AC of the ground complex performed during system design period.