• 제목/요약/키워드: Complex parts

검색결과 919건 처리시간 0.033초

주택성능등급표시제도의 개선을 위한 인정 단지의 사업계획변경 현황에 대한 실태조사 연구 (A Study on the Business Plan Changes of Housing Complex evaluated by the "Housing Performance Grading Indication System")

  • 이성옥;배철학
    • KIEAE Journal
    • /
    • 제11권6호
    • /
    • pp.43-51
    • /
    • 2011
  • This study aims to analyze on the change status in the project plan of the housing complex as evaluated through the Housing Performance Grading Indication System. This a a system for assessing quantitatively the comprehensive, unified performance of housing by an objective standard from the design stage since January 9, 2006. As housing is a composite with various performances, it is required necessary to objectively assess the various performances from the design stage for building better housing. Thus, this study analyzed the change status and objectively described objectively it centering on the construction and structure drawings for 12 items posted in the Facility Management System_(FMS) out of examples recognized by 2011 since the implementation of the system. The changes were analyzed though observing each performance item-specific characteristics and confirming the books approved for use. In various parts, such as the site area, landscape plan, plane plan for unit, supplementary welfare facility plan, finishing materials, window size and location, the project plan was changed. These changes may result in a grading change in of the performance items of the system. This study purpose is for it to be used as a basic resource required for future system development by supplementing the limitation of the design phase and then through playing a basic role for the assessment after completion.

Catching-Up and National Environment: The Case of the Korean Aircraft Industry

  • Hwang, Chin-Young
    • 한국기술혁신학회:학술대회논문집
    • /
    • 한국기술혁신학회 2000년도 추계 학술대회(The 2000 Autumn Conference of korea Technology Inovation Society)(한국기술혁신학회)
    • /
    • pp.227-245
    • /
    • 2000
  • Korean firms have attempted to catch up in the aircraft industry during last quarter century. Korean firms have built up their capabilities by moving from parts manufacturing through subassembly to system integration. The number of projects carried out and the intensity of technological effort undertaken by firms strongly influences market position and firm performance. However, successful catching up is not simply dependent on capability building within the firm. The national environment (Porter, 1990) in which firms are located plays a pivotal role. The Korean government has been effective in creating a favorable environ-ment in many areas, but has not been able to replicate this success in the aircraft industry. Opportunities for learning in the aircraft industry have been hampered by the small size of the Korean civilian aircraft market and the sophisticated requirements of military systems. A policy of domestic rivalry in airframe manufacture has created too many firms for such a small market. The ability of Korean firms to catch up in the aircraft industry depends on both the internal capabilities of firms as well as appropriate government policies and the involve- ment of government research institutions and universities over an extended period of time. There have been many studies about the catching up of developing countries in mass production (such as automobile, consumer electronics, and recently DRAM), but few in complex systems, such as aircraft.

  • PDF

분말사출성형을 이용한 치과용 스케일러 팁의 진동특성 개선에 관한 연구 (A Study for Vibrational Characteristics Improvement of Dental Scaler Tip using Powder Injection Molding)

  • 황철진;김종선;고영배;정성택
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 2006년도 춘계학술대회 논문집
    • /
    • pp.343-344
    • /
    • 2006
  • Powder injection molding(PIM) is widely used for many parts in the field of automotives, electronics and medical industries, due to the capability of net shaping for complex 3-D geometry. Powder injection mold design fur the dental scaler tip, a component of medical appliance, was presented. In comparison with conventional machining process, powder injection molding has many advantages, specially in price and dimensional stability, for molding dental scaler tip which has complex geometry. Both product design and mold design for dental scaler tip were presented. The 'rapid mold' concept was applied to manufacture the various forms of dental scaler tip.

  • PDF

Surf points based Moving Target Detection and Long-term Tracking in Aerial Videos

  • Zhu, Juan-juan;Sun, Wei;Guo, Bao-long;Li, Cheng
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제10권11호
    • /
    • pp.5624-5638
    • /
    • 2016
  • A novel method based on Surf points is proposed to detect and lock-track single ground target in aerial videos. Videos captured by moving cameras contain complex motions, which bring difficulty in moving object detection. Our approach contains three parts: moving target template detection, search area estimation and target tracking. Global motion estimation and compensation are first made by grids-sampling Surf points selecting and matching. And then, the single ground target is detected by joint spatial-temporal information processing. The temporal process is made by calculating difference between compensated reference and current image and the spatial process is implementing morphological operations and adaptive binarization. The second part improves KALMAN filter with surf points scale information to predict target position and search area adaptively. Lastly, the local Surf points of target template are matched in this search region to realize target tracking. The long-term tracking is updated following target scaling, occlusion and large deformation. Experimental results show that the algorithm can correctly detect small moving target in dynamic scenes with complex motions. It is robust to vehicle dithering and target scale changing, rotation, especially partial occlusion or temporal complete occlusion. Comparing with traditional algorithms, our method enables real time operation, processing $520{\times}390$ frames at around 15fps.

박판성형기술의 개발과 적용 (The Development and Application of Sheet Metal Forming Technology)

  • 박춘달;이장희;양동열;허훈;정동원
    • 한국소성가공학회:학술대회논문집
    • /
    • 한국소성가공학회 1994년도 박판성형기술의 진보
    • /
    • pp.147-162
    • /
    • 1994
  • Generally, the forming process of sheet metal is very complex and difficult process because of many variables such as tool geometry, material properties and lubrication. In this view point, the numerical analysis of sheet metal forming process is very difficult. High speed computer is used to model complex sheet metal forming process on a reasonable time scale. The design and development of sheet metal parts in the automotive industry and the need for improved sheet forming process and reduced part development cost have led to the use of computer simulation in tool/die design of sheet metal pressing. HMC(Hyundai Mator Company) has invested to develop programs for analysis of sheet metal forming process with connection of Universities. As a result, several programs were developed. Recently, the commercial software, PAM-STAMP of ESI was installed and is being tried to application of it to the real automotive panels. This article reviews the ongoing activities on development and application of analytical modeling of sheet metal forming at HMC.

자유형상 커튼월 구현을 위한 3D 프린팅을 활용한 스마트노드 시스템의 연구 (Study on the Connection Node System of Irregular-shaped Curtain wall Facade using 3D Printed Smart Node System)

  • 나상호;유승규;박영미;박정준;김성진
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2018년도 추계 학술논문 발표대회
    • /
    • pp.8-9
    • /
    • 2018
  • 3D printing has the unique advantage of the ability to customize freeform product even in small quantity. However, we need to select and apply the only necessary parts of it because of the high cost of the manufacturing technology. It is of critical importance in irregular-shaped curtain walls to ensure precision of construction as well as quality fo finish. Complex shape that have structural members at varying angles can have nodes of different shapes making it unfeasible to construct using a general node connection detail. Therefore, this study aims to utilize smart node system using 3D printing as a solution to complex irregular-shaped curtain wall design.

  • PDF

Dynamically Adaptive Finite Element Mesh Generation Schemes

  • Yoon, Chong-Yul;Park, Joon-Seok
    • 한국전산구조공학회논문집
    • /
    • 제23권6호
    • /
    • pp.659-665
    • /
    • 2010
  • The finite element method(FEM) is proven to be an effective approximate method of structural analysis if proper element types and meshes are chosen, and recently, the method is often applied to solve complex dynamic and nonlinear problems. A properly chosen element type and mesh yields reliable results for dynamic finite element structural analysis. However, dynamic behavior of a structure may include unpredictably large strains in some parts of the structure, and using the initial mesh throughout the duration of a dynamic analysis may include some elements to go through strains beyond the elements' reliable limits. Thus, the finite element mesh for a dynamic analysis must be dynamically adaptive, and considering the rapid process of analysis in real time, the dynamically adaptive finite element mesh generating schemes must be computationally efficient. In this paper, a computationally efficient dynamically adaptive finite element mesh generation scheme for dynamic analyses of structures is described. The concept of representative strain value is used for error estimates and the refinements of meshes use combinations of the h-method(node movement) and the r-method(element division). The shape coefficient for element mesh is used to correct overly distorted elements. The validity of the scheme is shown through a cantilever beam example under a concentrated load with varying values. The example shows reasonable accuracy and efficient computing time. Furthermore, the study shows the potential for the scheme's effective use in complex structural dynamic problems such as those under seismic or erratic wind loads.

자동차 드럼 브레이크의 스퀼 전산 해석 연구 (Computational Study of Automotive Drum Brake Squeal)

  • 정택수;조종두
    • 한국자동차공학회논문집
    • /
    • 제22권7호
    • /
    • pp.16-22
    • /
    • 2014
  • Automotive NVH on brake operation is mainly caused by a coupling action of vehicle speed and inter parts friction and its frequency occurs over a broad band of 0.1 kHz~10 kHz. Especially, squeal noise, being a self-excited vibration generated by friction force between drum and lining, occurs over 1 kHz and consequently dynamic instability is induced when friction energy is applied to a brake vibration system. The squeal strongly depends on nonlinear properties influenced by the material of lining, velocity of vehicle, and the dynamic properties of a brake system. The dynamic properties are considered as a main influential design factor to squeal noise, however the analysis of the properties are rarely facilitated due to arbitrariness of shape by wearing down. In this paper, we research generating tendency of squeal noise through complex eigenvalue analysis, tracking drum brake's unstable modes in accordance with the wear shape of drum and lining such as tapered and bellmouth shape, and analyze computed unstable modes by variable shapes.

An Algorithm for Calculating the RMS Value of the Non-Sinusoidal Current Used in AC Resistance Spot Welding

  • Zhou, Kang;Cai, Lilong
    • Journal of Power Electronics
    • /
    • 제15권4호
    • /
    • pp.1139-1147
    • /
    • 2015
  • In this paper, an algorithm based on a model analysis of the online calculation of the root-mean-square (RMS) value of welding current for single-phase AC resistance spot welding (RSW) was developed. The current is highly nonlinear and typically non-sinusoidal, which makes the measuring and controlling actions difficult. Though some previous methods focused on this issue, they were so complex that they could not be effectively used in general cases. The electrical model of a single-phase AC RSW was analyzed, and then an algorithm for online calculation of the RMS value of the welding current was presented. The description includes two parts, a model-dependent part and a model-independent part. Using a previous work about online measurement of the power factor angle, the first part can be solved. For the second part, although the solution of the governing equation can be directly obtained, a lot of CPU time must be consumed due to the fact that it involves a lot of complex calculations. Therefore, a neural network was employed to simplify the calculations. Finally, experimental results and a corresponding analysis showed that the proposed algorithm can obtain the RMS values with a high precision while consuming less time when compared to directly solving the equations.

빛과 공간예술에서 빛에 의한 공간의 표현특성에 관한 연구 (A Study on Design Characteristics of Artistic Space effected by Light in 'Light and Space Art')

  • 서정연
    • 한국실내디자인학회논문집
    • /
    • 제14권4호
    • /
    • pp.35-44
    • /
    • 2005
  • Light is the essential and symbolical entity In architecture. But the meaning of light has been changed as time has passed, and today it has plural meaning and more sophisticated role. Since 1960's 'Light and Space Art' has accomplished many successful experiments through light and space as artistic media, and they have changed the understanding of light from the electrical source to the phenomenological energy and sensual medium. And also the role of space in their works takes the more human-oriented field constituted from the coherent relationship of internal parts including human being. Light could be 'an object' and 'material' under 'Light and Space Art' artists' persistent efforts. They revealed another realm of spatial experiences such as extension-the metaphysical space, heterogeneous relationship-the complex space, and dematerialization-the illusionary space. The secondary and inclusive effects by 'Light and Space Art' can be found In the phenomenological architecture, the post-modern architecture, and the immaterial tendency of contemporary architecture. However, the more close connections between 'Light and Space Art' and the specific architectures are still left as a portion aside for the further research.