• 대한기계학회논문집A
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• 제31권11호
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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.

• 대한인간공학회:학술대회논문집
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• 대한인간공학회 1995년도 춘계학술대회논문집
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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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• 제어로봇시스템학회 2004년도 ICCAS
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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.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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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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• 제1권4호
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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.

• 소성∙가공
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• 제32권3호
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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.

• 복식
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• 제63권3호
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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.

• 한국공간구조학회논문집
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• 제7권3호
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• pp.125-132
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• 2007

본 연구의 주목적은 공간그리드의 조형요소로서 3차원 유닛의 역할과 구성을 탐구하는 것이다. 따라서 공간그리드와 3차원 유닛의 상호관계와 역할, 유닛의 유형 및 구성방식과 이에 영향을 미치는 요인들이 파악된다. 또한 각각의 형태적 특성 및 조합이 공간그리드 전체의 형상에서 드러내는 효과를 확인하여 전반적인 형태구성의 틀을 제시하고자 한다.

• 디자인학연구
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• 제13권3호
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• pp.235-244
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• 2000

현대 커뮤니케이션 디자이너는 시각적 혹은 형태적인 운영이나 해석은 물론 컨텐츠의 개발과 스토리 텔러로서 의 역할이 요구된다. 그러나 커뮤니케이션 디자이너들에게 있어서 컨텐츠를 이루는 이야기 구조에 대한 이해와 실험은 아직도 미미한 상태이다. 특히 디지털 기술의 급속한 발달로 인하여 80년대부터 타이포그라피의 영역은 정적인 형태에서 역동적인 형태를 갖는 Type in Motion으로 빠르게 전이되고 있다. 이에 스토리의 내용과 구조를 가장 잘 표현 할 수 있는 수단으로서의 Type in Motion에 관한 체계적인 연구가 필요하게 되었다. 본 논문은 이러한 컨텐츠로서의 스토리를 형태로서의 Type in Motion 기법을 이용해서 어떻게 효과적으로 표현 할 수 있는가를 연구한 것이다. . Type in Motion의 구성요소를 통해서 스토리의 함축적인 표현 방법과 기능적인 표현 방법을 분석하였다. 오늘날 디지털 기술이 디자이너에게 많은 혜택을 가져다 준 것은 사실이지만 한편으로는, 디지털 디자인의 효율적인 운영을 위해서는 다양한 분야의 지식이 필요하다. 따라서 디지털 타이포그라피를 다루는 디자이너도 시각언어로서의 Type in Motion뿐 아니라 음성언어로서의 Type in Motion에 대한 이해와 연구가 필요하다. 이런. 관점에서 스토리와 Type in Motion를 전체론 적 관점에서 해석하고 이들의 유기적 관계를 탐구하는 것은 효과적인 디지털 타이포그라피의 운영에 있어서 필수적이라고 하겠다.

• 대한건축학회논문집:계획계
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• 제34권3호
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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.