• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.11
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• pp.1053-1058
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• 2007

Micro-EDM technology (or the manufacture of miniature parts is used to make a micro hole. Two electrode shaping methods, mechanical electrode grinding and WEDG technique, have been studied. In this study, an electrode shaping method by using previously machined hole is introduced in order to obtain an optimal hole-making condition. Key factors such as applied voltage, capacitance, feedrate, and hole-dimension have an influence on the fabricating error of electrode shaping, which are taper ratio of a hole, electrode form accuracy, and electrode surface. Therefore, we try to investigate the optimal fabricating of electrode shaping from various experiments. Results from experiments, it was able to minimize the electrode fabricating error as voltage increases, and also applied feedrate and capacitance decreases.

• Proceedings of the ESK Conference
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• 1995.04a
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• pp.30-34
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• 1995

The operator's performance of nuclear power plants is affected by many performance shaping factors(PSF). The objective of this study is to find out the PSFs and their effect on the nuclear power plant operations. We extracted PSFs in five category, and identified the relationships between PSFs and performance using the four survey methods; literture survey, case study, video task analysis and questionnaire survey. Finally the knowledge on PSFs and their effect was represented as rule form for cognitive simulation.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.326-329
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• 2004

In this paper, we show a new form of blood pressure controller combined PI control with $H_{\infty}$ loop-shaping. Hypertensive patients or post-operative patients need to maintain normally blood pressure. Exact regulation of blood pressure is needed for maintaining variable blood pressure of preventing complications. The regulation of blood pressure is achieved by injecting drugs, and usually sodium nitroprusside is used as those kinds of drugs. It is necessary to control the infusion rate sodium-nitroprusside carefully to achieve the desired blood pressure. It has been known that regulation of blood pressure by automatic controller is more effective than regulation of blood pressure by human operators. The control of blood pressure has many constraints and uncertainties. Most of biological system has the time-varying variables and the side effects such as increased risk of sepsis and organ failure. To solve such a problem, we design a new robust PI controller using $H_{\infty}$ loop-shaping to decrease noise effects that come out from human body and errors for time delay. The system with designed controller shows more stable control of mean blood pressure and more robust performance for uncertainties. Validation methods for the control performance are confirmed to computer simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1995.10a
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• pp.71-74
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• 1995

Diamond shaping is one of the machining strategies to make the optical micro-groove molds,and it is especially useful when rhe component is an assembly of the linear micro-groove array. A mirror-like surface and arbitrary crose-sectional curve can be easily made by diamond. Howerver, the cutting speed of shaping is relatively lower than that of the other cutting methods, and there exist an unstable cutting conditions that generate the chatter. This study is focused on the modeling of the simplified self-induced chatter of the diamond shapping. Form the chatter model and experiments, it is found that the unstable cutting conditions exist wwhen the depth of cut is low and cutting speed is high.

• International Journal of Control, Automation, and Systems
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• v.1 no.4
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• pp.412-430
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• 2003

In many practical problems in signal processing and control, the signal values are often restricted to belong to a finite number of levels. These questions are generally referred to as "finite alphabet" problems. There are many applications of this class of problems including: on-off control, optimal audio quantization, design of finite impulse response filters having quantized coefficients, equalization of digital communication channels subject to intersymbol interference, and control over networked communication channels. This paper will explain how this diverse class of problems can be formulated as optimization problems having finite alphabet constraints. Methods for solving these problems will be described and it will be shown that a semi-closed form solution exists. Special cases of the result include well known practical algorithms such as optimal noise shaping quantizers in audio signal processing and decision feedback equalizers in digital communication. Associated stability questions will also be addressed and several real world applications will be presented.

• Transactions of Materials Processing
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• v.32 no.3
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• pp.114-121
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• 2023

During rolling, rolling mill rolls endure wear when shaping metal billets into a desired form, such as bars, plates, and shapes. Such wear affects the lifespan of the rolls and product quality. Therefore, in addition to rigidity, wear performance is a key factor influencing the performance of rolling mill rolls. Conventional methods such as casting and forging have been used to manufacture rolling mill rolls. However, powder alloying methods are increasingly being adopted to enhance wear resistance. These powder manufacturing methods include atomization, canning to shape the powder, hot isostatic pressing to combine the powder alloy with conventional metals, and various wear performance tests on rolls prepared with powder alloys. In this study, numerical simulations and experimental tests were used to develop and elucidate the wear analysis mechanism of rolling mill rolls. The wear characteristics of the rolls under various rolling conditions were analyzed. In addition, experimental tests (wear and surface analysis tests) and wear theory (Archard wear model) were used to evaluate wear. These tests were performed on two different materials in various powder states to evaluate the different aspects of wear resistance. In particular, this study identifies the factors influencing the wear behavior of rolling mill rolls and proposes an analytical approach based on the actual production of products. The developed wear analysis mechanism can serve the future development of rolls with high wear resistance using new materials. Moreover, it can be applied in the mechanical and wear performance testing of new products.

• Journal of the Korean Society of Costume
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• v.63 no.3
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• pp.61-77
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• 2013

The purpose of this study is to analyze the concept and characteristics of parody, and consider how parody was reflected in Thom Browne's collection centering on the expressive method. Thus, this study will attempt to shed new light on the creative possibility and artistic value of parody in men's fashion design. The methods are as follows. The ideas, characteristics and expressive methods that represent parody was considered by referencing various related books, papers, art critiques, etc. Based on this theoretical study, a case of Thom Browne's collection (Thom Browne menswear: 2004 S/S-2012 F/W) was observed to find types of parody, attributes and significance. Photo material was collected through websites such as www.thombrowne.com, www.style.com, etc. The type and characteristics of parody expressed in Thom Browne's collection was considered in the following aspects: imitative parody, critical parody and pastiche parody. Through such consideration, it was possible to realize the fashion designs that adapt Thom Browne's parody are very deliberate and calculative. The designs convey exaggeration, destruction of form, emphasis on discontinuity, transition into attraction, aesthetics of unfamiliarity, characteristic aspects of irrationality and contradiction. Through the study, it was possible to see Thom Browne's collection with parody adaptation shaping new creativity and broadening formative aspects in fashion design.

• Journal of Korean Association for Spatial Structures
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• v.7 no.3 s.25
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• pp.125-132
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• 2007

The purpose of this study is to investigate the functions and formations of the component units as aesthetic components in the spatial grid. The main subject covered here is the presentation of the morphological method of shaping spatial grid by application of 3-dimensional units satisfying the suitable form of polyhedra, tensegrity and hybrid structure. In accordance with the subject, the definition of the spatial grid and 3-dimensional nit, the relationship between them, and then the functions of those units are reviewed. And the formations of polyhedral units, tensegrity units and hybrid units are generated by means of the modules of the simplest type or pattern. And also the overall appearance of the spatial grid shaped by several basic methods in which one unit can be joined to another and arranged are depicted.

• Archives of design research
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• v.13 no.3
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• pp.235-244
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• 2000

The form or interpretation of today's communication design lies in content development and storytelling to the designer. However, the understanding as well as exteriment of the mechanisms behind content creation remain an obscure concept. Particularly given the rapid development of digital technology, since the 1980s typography has been quickly transforming itself from its static state to the more dynamic'Type in Motion'. following this came the need for solid research in'Type in Motion'as the best means of presenting story content and form The previous passage has studied the effectiveness of'Type in Motion'in presenting this kind of content. Type in Motion has allowed vast developments in the methods of story presentation. It is Due that today's digital technology has given many benefits to the designer, but on the other hand, it has required a more diverse understanding of digital design. furthermore, even the designers in digital typography lack the understanding and research in'Type in Motion'not only as a mode of visual language but also of verbal language. Given this point· in hand, the entire interpretation and interrelation of story and'Type in Motion'can be considered essential, given their shaping of effective digital typography.

• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.3
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• pp.11-21
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• 2018

This paper explores the structure of space in architecture from a viewpoint that individual unitized spaces are gathered to form the whole. To understand the spatial structure of architecture, firstly we need to understand each unitized spaces, and secondly, one must understand how the following adjacent spaces are connected to form the whole building. this gives salience to a fact that understanding the whole comprehensively. It is the most fundamental bases that must be understood and unitized when understanding the spatial structure of an existing building and designing a new one. It is necessary to hypostatize space as an abstract notion. In regards to this space examines the logical flow of structure within actual space. Hypostasieren process includes the process of shaping space and the shape information. In this process we need to refer to the properties of space and the morphological characteristics of physical elements. The segment of the unitized space is the realization process of the basic space. This study aims to provide a theoretical basis for analysis and design of spatial structure by comparing several representative methods of segmenting unitized space.