• Korean Institute of Interior Design Journal
• /
• v.22 no.6
• /
• pp.29-39
• /
• 2013

Architecture has been expressed a complexity of their civilization with evolving into a living spaces and a crystalloid of culture in the times. So, architecture is always a dramatic phenomenon related to architectural aesthetic and technical expression in harmony with social and cultural issues by the times. From this point of view, we can describe that architecture is one of an important mediators to analyze the integrated trend of time. Specially an expressed building envelop which is a matter of consequence in the architectural component is first visual factor including architectural meaning and historical back ground. Therefore, this study firstly starts an investment for discriminative characteristics of building envelop design in the times, then will take the comparative analysis related with modern age and contemporary age based on phases of the times. This research will give the chance to prepare of the pillar of future envelop design in the practical affairs and has simultaneously the chance to understand of inclusive envelop design methodology by the changes of the times.

• Wind and Structures
• /
• v.13 no.4
• /
• pp.309-326
• /
• 2010

CFD techniques try to find their way in the bridge engineering realm nowadays. However, there are certain fields where they offer superior performance such as conceptual bridge design and bidding design. The CFD studies carried out for the conceptual design of a 425 m length cable-stayed bridge are presented. A CFD commercial package has been employed to obtain for a set of cross-sections the aerodynamic coefficients considering 2D steady state. Additionally, for those cross-sections which showed adequate force coefficients, unsteady 2D simulations were carried out to detect the risk of vortex shedding. Based upon these computations the effect on the aerodynamic behavior of the deck cross-section caused by a number of modifications has been evaluated. As a consequence, a new more feasible cross-section design has been proposed. Nevertheless, if the design process proceeds to a more detailed step a comprehensive set of studies, comprising extensive wind tunnel tests, are required to better find out the aerodynamic bridge behavior.

• Proceedings of the KIEE Conference
• /
• 2005.10b
• /
• pp.146-148
• /
• 2005

In this paper, we propose a genetically optimized identification of information granulation(IG)-based fuzzy model. To optimally design the IG-based fuzzy model we exploit a hybrid identification through genetic alrogithms(GAs) and Hard C-Means (HCM) clustering. An initial structure of fuzzy model is identified by determining the number of input, the seleced input variables, the number of membership function, and the conclusion inference type by means of GAs. Granulation of information data with the aid of Hard C-Means(HCM) clustering algorithm help determine the initial paramters of fuzzy model such as the initial apexes of the membership functions and the initial values of polyminial functions being used in the premise and consequence part of the fuzzy rules. And the inital parameters are tuned effectively with the aid of the genetic algorithms and the least square method. And also, we exploite consecutive identification of fuzzy model in case of identification of structure and parameters. Numerical example is included to evaluate the performance of the proposed model.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.384-386
• /
• 2009

This paper introduces an effectively optimized Fuzzy model identification by means of complex and nonlinear system applying PSO algorithm. In other words, we use PSO(Particle Swarm Optimization) for identification of Fuzzy model structure and parameter. PSO is an algorithm that follows a collaborative population-based search model. Each particle of swarm flies around in a multidimensional search space looking for the optimal solution. Then, Particles adjust their position according to their own and their neighboring-particles experience. This paper identifies the premise part parameters and the consequence structures that have many effects on Fuzzy system based on PSO. In the premise parts of the rules, we use triangular. Finally we evaluate the Fuzzy model that is widely used in the standard model of gas data and sew data.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• v.31B no.6
• /
• pp.43-52
• /
• 1994

A design method of rule-based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of ``IF....,THEN...', using the theories of optimization theory , linguistic fuzzy implication rules and fuzzy c-means clustering. Three kinds of method for fuzzy modeling presented in this paper include simplified inference (type I), linear inference (type 2), and modified linear inference (type 3). In order to identify premise structure and parameter of fuzzy implication rules, fuzzy c- means clustering and modified complex method are used respectively and the least sequare method is utilized for the identification of optimum consequence parameters. Time series data for gas furance and those for sewage treatment process are used to evaluate the performance of the proposed rule-based fuzzy modeling. Comparison shows that the proposed method can produce the fuzzy model with higher accuracy than previous other studies.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.31 no.1 s.256
• /
• pp.62-69
• /
• 2007

Micromanipulator is a device that manipulates an object with high precision. Generally, a parallel-type robot has inherently higher precision than a serial-type robot. In most cases, the use of flexure hinge mechanisms is the most appropriate approach to micromanipulators. The micromanipulator is basically required that have high natural frequency and sufficient workspace. However, previous designs are hard to satisfy the required workspace and natural frequency, simultaneously, because the previous micromanipulators are coupled designs. Therefore, this paper suggests a new design parameter as displacement amplifier and new design procedure based on semi-coupled design in axiomatic design. As a consequence the spatial 3-DOF micromanipulator which is chosen as an exemplary device has natural frequency of 500Hz and workspace of $-0.5^{\circ}{\sim}0.5^{\circ}$. To investigate the effectiveness of the displacement amplifier, simulation and experiment are performed.

• Journal of the Korean Institute of Educational Facilities
• /
• v.14 no.4
• /
• pp.53-65
• /
• 2007

The present research has been conducted on the arranged form, the number and kinds, the area, the location of the rooms and the variation on exterior designs, based on a layout and a ground plan of each step, which are general plan, VE proposal and the final negotiation, for 11 elementary and middle and high schools that are designed in the way of BTL project. In consequence, it has been found out that there are some changes in the number and position of the rooms. However, the changes are not exceeding the overall arrangement form. This could not have led to the original aim, which is to induce creativity by PFI. It can be supposed that it is because the BTL system is stick to the old process, the method of financial investment and it is true to say that there needs to be solution for that.

• Journal of Biomedical Engineering Research
• /
• v.22 no.3
• /
• pp.285-291
• /
• 2001

In this paper, we designed two preprocessing adaptive filter - high pass filter and notch filter - using FPGA. For minimizing the calculation load of multi-channel and high-resolution ECG system, we utilize FPGA rather than digital signal processing chip. To implement the designed filters in FPGA, we utilize FPGA design tool(Altera corporation, MAX-PLUS II) and CSE database as test data. In order to evaluate the performance in terms of processing time, we compared the designed filters with the digital filters implemented by ADSP21061(Analog Devices). As a result, the filters implemented by FPGA showed better performance than the filters based on ADSP21061. As a consequence of examination, we conclude that FPGA is a useful solution in multi-channel and high-resolution signal processing.

• Journal of Ship and Ocean Technology
• /
• v.1 no.1
• /
• pp.57-72
• /
• 1997

The larger trends related to cracking in ocean going vessels (primarily tankers and bulk carriers) are reviewed on the basis of available data. The typical interrelated causes of such cracking are: high local stresses, extensive use of higher strength steels, inadequate treatment of dynamic loads, adverse operational factors (harsh weather, improper vessel handling), and controllable structural degradation (corrosion, wear, stevedore damage). Three consequences of cracking are then discussed: structural failure, pollution, and increased maintenance. The first two, while rare, are potentially of high consequence including loss of life. The types of solutions that can be employed to improve the durability of ships in the face of fatigue cracking are then presented. For existing vessels, these solutions range from repairs based on structural analysis or service experience, control of corrosion, and enhanced surveys. For new vessels, the use of advanced design procedures that specifically address dynamic loads and fatigue cracking is necessary. As the preferred solution to the problem of cracking in ships, this paper advocates prevention by explicit design by first principles.

• Journal of the Korean Society of Safety
• /
• v.32 no.5
• /
• pp.168-178
• /
• 2017

In order to prevent major and chemical accidents, some of the plants which would like to install and operate hazard chemicals handling facilities must submit Off-site Consequence Analysis due to recent arisen leak accidents since 2015. A lot of chemical industrials choose gas detectors as mitigation equipment to early detect gas vapor. The way of placement of gas detectors has two methods; Code-based Design(CBD) and Performance-based Design. The CBD has principles for gas detectors to be installed with consideration for the place that is expected to accumulate gas, and the leak locations according to legal standards and technical guidelines, and has a possibility to be unable to detect by these rules to locate gas detectors by vapor density information. The PBD has two methods; a Geographic Method and Scenario based Method. The Scenario-based Method has been suggested to make up for the Geographic Coverage Method. This Scenario-based Method draw the best optimum placement of gas detectors by considering leak locations, leak speed information, leak directions and etc. However, the domestic placement guidelines just refers to the CBD. Therefore, this study is to compare existing placement location of gas detectors by the domestic CBD with placement locations, coverages and the number of gas detectors in accordance with the Scenario-based Method. Also this study has measures for early detecting interest of Vapor Cloud and suitable placement of gas detectors to prevent chemical accidents. The Phast software was selected to simulate vapor cloud dispersion to predict the consequence. There are two cases; an accident hole size of leak(8 mm) from API which is the highst accident hole size less than 24.5 mm, and a normal leak hole size from KOSHA Guide (1.8 mm). Detect3D was also selected to locate gas detectors efficiently and compare CBD results and PBD results. Currently, domestic methods of gas detectors do not consider any risk, but just depend on domestic code methods which lead to placement of gas detectors not to make personnels recognize tolerable or intolerable risks. The results of the Scenario-based Method, however, analyze the leak estimated range by simulating leak dispersion, and then it is able to tell tolerable risks. Thus it is considered that individuals will be able to place gas detectors reasonably by making objectives and roles flexibly according to situations in a specific plant.