비선형 보상기와 외란관측기를 이용한 공기압 실리더의 위치제어

장지성,Jang, Ji-Seong 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.9

A position controller which can achieve a specified dynamic performance irrespective of the different operating position of the pneumatic cylinder is proposed. The position controller developed in this paper is composed of a nonlinear compensator and a disturbance observer. The nonlinear compensator which feeds back position, velocity and acceleration is derived from the nonlinear dominating equations of the position control system to compensate for variation of dynamic characteristics of a pneumatic cylinder according to the change of the operating position. The disturbance observer including a simplified linear model is designed to reduce the effect of model discrepancy in the low frequency range which cannot be suppressed by the nonlinear compensator. The results of the experiments show that the position control performance maintains a designed performance regardless of the variations of an operating position of the pneumatic cylinder.

경영사례-최소 투자로 경제적인 돈사시설 설치하는 법

장지성,Jang, Ji-Seong 대한양돈협회 1995 養豚 Vol.17 No.1

반도체 메모리 제작장비에 있어서의 공기압 구동장치의 응용

장지성,강보식,조정대,Jang, Ji-Seong,Gang, Bo-Sik,Jo, Jeong-Dae 재료연구소 1999 機械와 材料 Vol.11 No.2

CIGS 박막태양전지 기술 및 동향

장지성,정중희,Jang, Ji-Seong,Jeong, Jung-Hui 한국전기전자재료학회 2016 전기전자재료 Vol.29 No.11

공기압 압력용기의 압력제어

장지성(Ji-Seong JANG),고대권(Dae-Kwon Koh),김영복(Young-Bok Kim) 한국동력기계공학회 2006 한국동력기계공학회 학술대회 논문집 Vol.- No.-

In this study, a robust controller to control pressure in a pneumatic pressure vessel with a long transmission line is proposed. Frequency response of transmission line using compressible fluid is changed by the flowing state of the fluid. So, if a fixed gain controller designed based on a model supposed the flowing state to a specific state, the performance of the control system could be degraded because of the modelling error. The controller designed in this study is composed of two parts. One is a feedback controller to improve a feedback characteristics and to compensate the influence of the variation of transfer characteristics of a transmission line owing to the change of flowing state and the other is a feedforward controller to regulate command following performance. The experimental results with the designed controller show that the robustness of the control system is achieved regardless of the change of the model of the transmission line. Therefore, the designed controller can be utilized for the performance improvement of a pressure control system with a long transmission line using compressible fluid.

Accurate Positioning of a Pneumatic Servo System

Ji-Seong Jang(장지성) 한국해양공학회 1998 韓國海洋工學會誌 Vol.12 No.4

본 논문에서는 공기압 액튜에이터를 사용한 정밀 위치 시스템을 이용하여 정밀 위치 제어를 수행한다. 본 논문에서 사용된 정밀 위치 제어 시스템은 저 마찰형 서보 테이블과 고속 제어 밸브로 구성되어 진다. 서보 테이블은 공기압 액튜에이터의 위치제어 성능에 악영향을 미치는 구동 피스톤의 씰(seal) 부분의 마찰력을 보상하기 위하여 공기압 베어링 기구를 채택하고 있다. 제어 밸브는 대역폭이 100㎐ 이상인 고속 제어 밸브를 사용했다. 그 결과, 구동 피스톤의 마찰력을 감소시킨 정밀 위치 제어 시스템을 사용함에 의하여 컨트롤러의 설계가 용이하고, 위치 제어 오차가 ±10 ㎛ 이내의 정밀한 위치제어가 가능함을 보였다.

흡입공기 온도에 의한 용적형 공기 압축기 성능 변화

장지성(Ji-Seong Jang),한승훈(Seoung-Hun Han),지상원(Sang-Won Ji) 한국동력기계공학회 2017 동력시스템공학회지 Vol.21 No.2

공기압 구동장치를 이용한 정밀위치제어

장지성(Ji Seong Jang) 유공압건설기계학회 2015 드라이브·컨트롤 Vol.12 No.4

The accurate position control of pneumatic driving apparatus is considered in this paper. In pneumatically actuated positioning systems, accurate positioning as an electrical servo has been known to be difficult because of the friction force and compressibility of the air. For good control performance of the pneumatic system, an actuator mounted with externally pressurized air bearings is produced to compensate for friction force. For the controller design, the governing equation of the pneumatic driving apparatus is derived. In order to reduce the nonlinear characteristics of the control valve, linearized control input is derived from the relation between the effective area of the valve and the control input. The experimental results are presented to show the results of the improved position control of the pneumatic driving apparatus.

산수화의 시방식 (視方式) 연구

장지성(Ji Seong Jang) 한국기초조형학회 2000 기초조형학연구 Vol.1 No.2

A set form is required to see something as its object is expressed in a picture. There are also some specifications of such form for oriental landscape paintings, which are quite different from those for western landscape paintings. In oriental landscape painting, which has its basis in the Chinese Laotzu-Chuangtzu philosophy that emphasized being united with nature for the happiness of the human being, to paint the landscape and appreciate it is considered as an expression of the intent or wish to be back to nature. In the world of such a concept, a picture seen in scale` not only shows a beautiful scene, but also comprises a small universe` in which natural beauty is expressed, hidden, and far off. To embody this concept in oriental painting, the conceptual specifications for the visual points in a picture are not fixed, but are shared and movable to the left, right, up, or down in all directions at your own will. Each individual scene is thought of or kept in mind to embody and comprehensively express all the points in a whole picture by mobilizing various visual points. A bugamsi, a kind of point of aerial view like a bird`s eye view, is required to comprehend and embody all the visual points.

전통화조화의 개념과 상징 해석에 대한 고찰

장지성(Jang Ji Seong) 한국미술교육학회 2008 美術敎育論叢 Vol.22 No.2

전통회화에 있어서 산수화?인물화와 함께 3대 화문인 화조화는 고려시대부터 순수한 감상을 위한 화조화가 그려지기 시작했으며, 양식적인 변천을 거듭하여 지금에 이르렀다. 꽃과 새는 사계절이 뚜렷하여 일찍이 자연합일의 사상이 발달한 동아시아에서 자연의 조화로움과 아름다움을 대변하니, 항상 예술과 문학의 주요 소재로 다루어져 왔다. 특히 소재가 지니는 다양한 상징은 화조화를 발전시키는 원동력이 되었다. 그러나 화조화는 하나의 화문(畵門)으로 볼 때 아직까지 정확한 범위가 어디까지인지 명확하지 않아 광의와 협의의 개념이 혼란스럽게 사용되고 있고, 전통 화조화를 감상하고 비평하는데 있어서 소재가 지니는 상징에 대한 편협한 해석으로 작품전체를 의미를 파악하지 못하는 경우가 있다. 이에, 이 연구는 전통화조화의 올바른 감상과 비평이 이루어지기 위해서는 우선적으로 화문으로서의 범위와 상징 해석의 문제를 명확하게 하는 것이 중요하리라 판단하였다. 그래서 첫째, 중국의 화보(畵譜)나 화사서(畵史書)의 화조화라는 용어의 사용례와 한국회화사에서의 화조화라는 용어사용에 대한 세밀한 고찰을 통해 보다 정확한 화조화의 개념과 범위를 제시하였다. 그리고 둘째, 화조 소재가 지니는 상징뿐만 아니라, 화조화 작품이 지니는 상징 해석의 중요성에 대해 이론적 근거를 제시하고, 실제 작품을 분석하여 작품의 의미를 밝히는데 다양한 상징 요소들이 존재함을 밝혔다. A flower-bird painting, one of three big styles with a landscape painting and a figure painting in traditional paintings, has been drawn since Goryeo era when people drew it for genuine appreciation and has changed its styles to come to current patterns. Flowers and birds have been main subject matters in arts and literature to express the harmony and the beauty of nature in East Asian countries where there are clear four seasons and Oriental thought that emphasizes the unity between human beings and nature. Especially the various symbols of the materials became the motive to develop flower-bird paintings. However, no one defines the exact meaning and range of flower-bird paintings and the concept of it both in a broad sense and a narrow sense creates confusion. Also narrow interpretation on the symbol of materials in appreciating and criticizing traditional flower-bird paintings sometimes works as an obstacle in the overall understanding of art works and distorts understanding and appreciation of traditional flower-bird paintings. Hence, in this research, I intended to suggest more clearer concept of flower-bird paintings by studying usage cases of the term "flower-bird painting" in Chinese picture books and painting history books and in Korean painting history. I also demonstrated that it is needed to examine what symbol flower-bird paintings have rather than what symbol materials in flower-bird paintings have, and found that there are various symbol factors to clarify the meaning of an artwork by analyzing real art works. In other words, I insisted that we need to prescribe the scope of flower-bird painting patterns by defining the concept of flower-bird paintings and read creativity of artist, era and culture in symbols of each art work to appreciate traditional flower-bird paintings properly, not just we find and understand forgotten traditional symbols in flower-bird paintings.