• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.320-325
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• 2006

The phenomenon of squeal in disc brakes has been, and stin is, a problem for the automotive industry. Extensive research has been done in an attempt to understand the mechanisms that cause it and in developing design procedures to reduce it to make vehicles more comfortable. In this paper, the study on squeal noise of disc brake is performed using complex eigen-value analysis, The first part describes the chassis-dynamometer and the testing procedure, and second part explains how the analysis is performed and shows some of the results from typical squeal tests. Finally, to reduce squeal nose of disc brake is investigated by the effects of brake design parameter.

• Korean Journal of Computational Design and Engineering
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• v.12 no.4
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• pp.283-297
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• 2007

Seamless data integration in the CAx chain of the CAD/CAPP/CAM/CNC has been achieved to a high degree, but research concerning the transfer of data from conceptual sketches to a CAD system should be carried out further. This paper presents a method for reconstructing a 3D model from a freehand sketch. Sketch-based modeling research can be classified into gestural modeling methods and reconstructional modeling methods. This research involves the reconstructional modeling method. Here, Mitani's seminal work, designed for box-shaped 3D model using a predefined template, is improved by leveraging a relational template and specialized for automotive design. Matching between edge graphs of the relational template and the sketch is formulated and solved as the assignment problem using the feature vectors of the edges. Including the stroke preprocessing method required to generate an edge graph from a sketch, necessary procedures and relevant techniques for implementing the template-based modeling method are described. Examples from a working implementation are given.

• Transactions of the Korean Society of Automotive Engineers
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• v.20 no.6
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• pp.1-8
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• 2012

Multidisciplinary design optimization (MDO) for a suspension component of the vehicle front suspension was performed in this research. Shapes and thicknesses of the subframe were optimized to satisfy multi-disciplinary design requirements; weight, fatigue, crash, noise, vibration, and harshness (NVH), and kinematic and compliance (K&C). Analyses procedures of the performance disciplines were integrated and automated by using the process integration and design optimization (PIDO) technique, and the integrated and automated analyses environments enabled various types of analytic design methodologies for solving the MDO problem. We applied an approximate optimization technique which involves sequential sampling and metamodeling. Since the design variables for thicknesses should be dealt as discrete variables. the evolutionary algorithm is selected as optimization technique. The MDO problem was formulated three types of problems according to the order of priorities among the performance disciplines, and the results of MDO provided design alternatives for various design situations.

• 전기의세계
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• v.29 no.10
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• pp.678-688
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• 1980

This paper is concerned with the computer design of the multiple-output switching functions by using the improved MASK method in order to obtain the paramount prime implicants (prime implicants of the multiple-output switching function) and new algorithm to design the optimal logic network. All the given minterms for each function are considered as minterms of one switching function to simplify the desigh procedures. And then the improved MASK method whose memory requirement and time consuming are much less than any existing known method is applied to identify the paramount prime implicants. In selecting the irredundant paramount prime implicants, new cost criteria are generated. This design technuque is suitable both for solving a problem by hand or programming it on a digital computer.

• Journal of the HCI Society of Korea
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• v.12 no.4
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• pp.37-44
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• 2017

Eye-typing is one kind of human-computer interactive input system which is implemented by location data of gaze. It is widely used as an input system for paralytics because it does not require physical motions other than the eye movement. However, eye-typing interface based on Korean character has not been suggested yet. Thus, this research aims to implement the eye-typing interface optimized for Korean. To begin with, design objectives were established based on the features of eye-typing: significant noise and Midas touch problem. Multilevel input system was introduced to deal with noise, and an area free from input button was applied to solve Midas touch problem. Then, two types of eye-typing interfaces were suggested on phonological consideration of Korean where each syllable is generated from combination of several phonemes. Named as consonant-vowel integrated interface and separated interface, the two interfaces are designed to input Korean in phases through grouped phonemes. Finally, evaluation procedures composed of comparative experiments against the conventional Double-Korean keyboard interface, and analysis on flow of gaze were conducted. As a result, newly designed interfaces showed potential to be applied as practical tools for eye-typing.

• Journal of Radiation Protection and Research
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• v.42 no.4
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• pp.212-221
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• 2017

Background: This study aims to calculate detector positions as a design of a radioactive source localizing radiation portal monitor (RPM) system using an improved genetic algorithm. Materials and Methods: To calculate of detector positions for a source localizing RPM system optimization problem is defined. To solve the problem, a modified iterative genetic algorithm (MIGA) is developed. In general, a genetic algorithm (GA) finds a globally optimal solution with a high probability, but it is not perfect at all times. To increase the probability to find globally optimal solution rather, a MIGA is designed by supplementing the iteration, competition, and verification with GA. For an optimization problem that is defined to find detector positions that maximizes differences of detector signals, a localization method is derived by modifying the inverse radiation transport model, and realistic parameter information is suggested. Results and Discussion: To compare the MIGA and GA, both algorithms are implemented in a MATLAB environment. The performance of the GA and MIGA and that of the procedures supplemented in the MIGA are analyzed by computer simulations. The results show that the iteration, competition, and verification procedures help to search for globally optimal solutions. Further, the MIGA is more robust against falling into local minima and finds a more reliably optimal result than the GA. Conclusion: The positions of the detectors on an RPM for radioactive source localization are optimized using the MIGA. To increase the contrast of the measurements from each detector, a relationship between the source and the detectors is derived by modifying the inverse transport model. Realistic parameters are utilized for accurate simulations. Furthermore, the MIGA is developed to achieve a reliable solution. By utilizing results of this study, an RPM for radioactive source localization has been designed and will be fabricated soon.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.35
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• pp.47-52
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• 1995

The aim of this paper is to suggest the cutting stock problems which are two-dimensional in form, but can be treated as the optimization methods for one-dimensional cutting stock problem by exploiting the length requirement of the products. The solution method consists of two stages. The first calculates the number of roll pieces of each size. Next, 1-dimensional cutting stock model is set up. One heuristic method to calculate the number of each roll is suggested. The trim loss minization criteria are used to design the objective function. This model can be solved by the conventional cutting stock procedures based on enumerating the possible cutting patterns.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.20 no.43
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• pp.25-36
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• 1997

The purpose of this paper is to structure a new integrated model that can minimize the total cost for the transportation and inventory systems between m origin points, where origin i has a supply of a commodity, such as distribution centers or warehouses, and n destination points, where destination j requires the commodity. In this case, demands of the destination points are assumed random variables which have a known probability distribution. We will find optimal distribution centers which transport the commodity to the destination points and suggest optimal inventory policy to the selected distribution center which find the optimal pair $$ and safety stock level that minimize total cost with back-ordered case. This new model is formulated as a 0-1 nonlinear integer programming problem. To solve the problem, this paper proposes heuristic computational procedures and program and provides numerical examples.

• Journal of Fisheries and Marine Sciences Education
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• v.25 no.1
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• pp.167-180
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• 2013

A capstone design is regarded as one of cap courses in undergraduate engineering education because it requires most prerequisites and makes students experience real engineering design processes. There have been case studies to show how this subject should be organized, practiced, and optimized. This study shows one of the case studies by focusing offshore wind power, one of newly recognized renewable energy resources, especially targeting for the design of wind turbine foundation and submarine power cable protectors mainly because of current energy and global warming crisis. To pinpoint engineering design, the students'activities during the project and design procedures are monitored, evaluated, and recommended; hence, core factors are addressed to develop successful aim, theory, practice, and other necessities. These factors include creative problem solving abilities; recognition of engineering curriculum; selection of project theme based on significance, ripple effect, and education purpose; team organization by the full brain model; systematization of project process; realization of engineering design; and synthesis of evaluation. In the end, the aftermath and future works are discussed.

• Steel and Composite Structures
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• v.1 no.1
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• pp.97-110
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• 2001

Architectural steel structures with visible tension and compression members are becoming more prevalent as a popular form of construction that reflects the nature of the resistance to the applied loads. These members require the use of structural steel pins at their ends to ensure either axial tension or axial compression in the members. Structural pins have been used as a means of connection for centuries and it would appear that their behaviour is relatively well understood. However, the rules for the design of pins vary quite considerably from code to code and this has caused some confusion amongst consulting structural engineers operating internationally. To provide some insight into this problem, a comprehensive testing program has been carried to examine the influence of parameters such as pin diameter, material properties of the pin, thickness of the loading plates, material properties of the loading plates and the distance of the pin to the edge of the loading plates. The modes of failure have been carefully examined. Based on this study, modifications to current design procedures are proposed that properly take into account the different possible modes of failure.