• 한국정밀공학회지
• /
• 제20권11호
• /
• pp.41-46
• /
• 2003

The objective of this paper is to present a methodology for automatically balancing multi-cavity injection molds with the aid of flow simulation. After the runner and cavity layout has been designed, the methodology adjusts runner and gate sizes iteratively based on the outputs of flow analysis. This methodology also ensures that the runner sizes in the final design are machinable. To illustrate this methodology, an example is used wherein a 3-cavity mold is modeled and filling of all the cavities at the same time is achieved. Based on the proposed methodology, a multicavity mold with identical cavities is balanced to minimize overall unfilled volume among various cavities at discrete time steps of the molding cycle. The example indicates that the described methodology can be used effectively to balance runner systems for multi-cavity molds.

• 대한전자공학회논문지SD
• /
• 제47권2호
• /
• pp.106-114
• /
• 2010

본 논문은 기가 스케일 System on Chip(SoC)를 위한 통합 설계 및 검증 플랫폼을 제안한다. VLSI 집적도의 발달로 그 복잡도가 증가하여 기존의 RTL 설계 방식으로는 그 생산성 차이(Production Gap)를 극복할 수 없게 되었다. 또한, 검증 차이(Verification Gap)의 증가로 검증 방법론에도 커다란 변혁이 필요하게 되었다. 본 플랫폼은 기존의 상위 수준 합성을 포함하며, 그 결과물을 이용하여 저 전력 설계의 전원 인식 검증 플랫폼과 검증 자동화를 개발하였다. 상위 수준 합성 시 사용되는 Control and Data Row Graph (CDFG)와 고 입력인 상위 수준 언어와 RTL를 기반으로 한 검증 플랫폼 자동화와 전원 인식 검증 방법론을 개발하였다. 검증 플랫폼에는 자동 검사 기능을 포함하고 있으며 Coverage Driven Verification을 채택하고 있다. 특히 전원 인식 검증을 위하여 개발된 조건 랜덤 벡터 생성 알고리듬을 사용하여 랜덤 벡터의 개수를 최소 5.75배 감소시키는 효과를 가져왔고, 전원과 전원 셀에 대한 모델링 기법을 이용하여 일반적인 로직 시뮬레이터 툴을 통해서도 전원 인식 검증을 가능하게 하였다. 이러한 통합된 설계 및 검증 플랫폼은 시스템 수준의 설계에서 검증, 합성에 이르는 전 설계 흐름을 완전 자동화 하여 상위 수준의 설계와 검증을 가능하게 하고 있다.

• Transactions on Electrical and Electronic Materials
• /
• 제15권3호
• /
• pp.149-154
• /
• 2014

A new CMOS analog design methodology using an independently optimized self-cascode (SC) is proposed. This idea is based on the concept of the dual-workfunction-gate MOSFETs, which are equivalent to SC structures. The channel length of the source-side MOSFET is optimized, to give higher transconductance ($g_m$) and output resistance ($r_{out}$). The highest $g_m$ and $r_{out}$ of the SC structures are obtained by independently optimizing the channel length ratio of the SC MOSFETs, which is a critical design parameter. An operational amplifier (OPAMP) with the proposed design methodology using a standard digital $0.18-{\mu}m$ CMOS technology was designed and fabricated, to provide better performance. Independently $g_m$ and $r_{out}$ optimized SC MOSFETs were used in the differential input and output stages, respectively. The measured DC gain of the fabricated OPAMP with the proposed design methodology was approximately 18 dB higher, than that of the conventional OPAMP.

• 전기학회논문지
• /
• 제58권3호
• /
• pp.573-577
• /
• 2009

Piezoresistive pressure sensor have become the successfully-commercialized MEMS product and the related technologies have been well developed over the past decades. Regarding the design methodology, however, the coupled-physics FEM analyses of the transducer itself and the signal-processing circuitry design based on the conventional EDA are separated and both of the analyses were sequentially processed for the full design of the pressure sensor. For the fast and effective R&D, new design methodology is proposed in this paper where the FEM results are linked to the EDA environment and therefore most of the design works can be done in the EDA environments, which means the time-consuming FEM analyses can be minimized. In order to verify the proposed approach, a typical piezoresistive pressure sensor having the silicon diaphragm and piezoresistors was modeled and analyzed based on the proposed methodology. The verification results showed that the simulated results were matched well with the measured data within the 7% difference while the simulation time was reduced less than 5% compared to the conventional methodology. Through the proposed approach, various types of the piezoresistive pressure sensors can be developed in more effective way.

• International Journal of Control, Automation, and Systems
• /
• 제5권5호
• /
• pp.515-525
• /
• 2007

In this paper, we develop a co-design methodology of stochastic optimal controllers and network parameters that optimizes the overall quality of control (QoC) in networked control systems (NCSs). A new dynamic model for NCSs is provided. The relationship between the system stability and performance and the sampling frequency is investigated, and the analysis of co-design of control and network parameters is presented to determine the working range of the sampling frequency in an NCS. This optimal sampling frequency range is derived based on the system dynamics and the network characteristics such as data rate, time-delay upper bound, data-packet size, and device processing time. With the optimal sampling frequency, stochastic optimal controllers are designed to improve the overall QoC in an NCS. This co-design methodology is a useful rule of thumb to choose the network and control parameters for NCS implementation. The feasibility and effectiveness of this co-design methodology is verified experimentally by our NCS test bed, a ball magnetic-levitation (maglev) system.

• Industrial Engineering and Management Systems
• /
• 제3권2호
• /
• pp.140-150
• /
• 2004

Repetitive stress injury at the wrist has been reported as a common injury among visual display terminal (VDT) users (i.e., computer users). Adjusting a VDT workstation (computer table and chair) to maintain a correct seated posture while operating a keyboard is perhaps the most frequently recommended preventive solution. This paper proposes an analytical design methodology based on ergonomic design principles for recommending appropriate VDT workstation settings and layout of individual computer accessories on the computer table. The proposed design methodology consists of two interrelated phases: (1) determination of VDT workstation settings, and (2) design of computer accessories layout. Based on the information about the VDT user, dominant task to be performed, typing skill, and degrees of physical and visual interactions between the user and computer accessories, adjustment and layout solutions are recommended to allow having a correct seated posture while minimizing both physical and visual movements. The results from an experiment show that when adjusting the workstation and locating the computer accessories according to the recommendations given by the proposed design methodology, the user's hand movements can be significantly reduced.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제55권2호
• /
• pp.69-75
• /
• 2006

This paper deals with the optimum design solution on reduction of torque ripple for a Synchronous Reluctance Motor with concentrated winding using response surface methodology. The coupled Finite Elements Analysis (FEA) & Preisach model have been used to evaluate the nonlinear solution. Comparisons are given with characteristics of a SynRM according to the stator winding, slot number, open width of slot, slot depth, teeth width variation in concentrated winding SynRM, respectively. This paper presents an optimization procedure using Response Surface Methodology (RSM) to determine design parameters for reducing torque ripple. RSM has been achieved to use the experimental design method in combination with finite Element Method (FEM) and well adapted to make analytical model for a complex problem considering a lot of interaction of design variables. Moreover, Sequential Quadratic Problem (SQP) method is used to solve the resulting of constrained nonlinear optimization problem.

• 대한산업공학회지
• /
• 제13권2호
• /
• pp.47-57
• /
• 1987

본 논문의 주된 목적은 APS(Activity Planning System)라고 불리우는 활동계획을 위한 간단한 대화식 소프트웨어 시스템을 설계하는데 있다. 여기에서는, 시스템 설계에 있어서 비형식적인 명세와 형식적인 명세의 중요성을 논하였고, 또한 몇가지 저명한 시스템 설계 방법론을 조사하였다. 그리고 APS를 설계하기 위하여 시스템의 계층구조적 분해에 의한 하나의 설계방법론을 제시하였고, 이 방법론을 응용하여 APS를 설계하였다.

• 디지털융복합연구
• /
• 제15권11호
• /
• pp.447-454
• /
• 2017

인간의 욕구는 기본적인 생활환경을 구성하는 요인에서부터 출발하게 된다. 안전 가이드라인 개발 모형은 행동유도를 통해 위협 요인의 발생 시점에서 집단 심리와 체계적인 환경에서 벗어난 의식의 절단에서 출발하게 된다. 안전 가이드라인 설계와 방법론은 시퀀스별 모형으로 주관화와 객관화가 반복해서 도출되어야 하며, 서비스 디자인 방법론을 통해 공공 서비스의 시간 순차적인 방향으로 설계되어야 한다. 다양하고 복잡한 위협요인은 감성경험과 사용자경험, 기술경험의 가치를 반영한 모형으로 구축하기 위해 사용자 관점, 관리자 관점의 모형으로 인사이트를 도출하고 안전 가이드라인 개발모형으로 추출하고자 한다. 명확한 설계와 자료조사를 통해 일반 사용자의 수평적, 수직적 사고의 문제를 전환시키고, 이해관계자의 프로토타입 도출과 인사이트를 도출하게 된다. 이렇게 도출된 인사이트는 안전 가이드라인 개발방법론은 동일한 문제의식에서 출발된 다차원 서비스 모형으로 구현될 수 있다.

• 한국멀티미디어학회논문지
• /
• 제22권2호
• /
• pp.292-298
• /
• 2019

Mobile-based software development methodology has been vigorously researched from using object-oriented development methodology and component-based development methodology previous structural developing methodology. There are two types of OS in mobile platform which are android and iOS. There is a problem that the application to be developed is developed depending on the device type. To resolve this problem, first, the system structure and design method should be managed effectively. Second, a basic design guide that can be commonly adapted to the each project is required. In this paper, we define a mobile cross platform meta model based on MDA-development methodology, focusing on reusability, portability and interoperability about non - dependent part of the mobile platform. If the proposed meta-model is applied to manage the related information and all the types of Mobile-Apps become available through independent mobile app development process, henceforward, it will be much of help establishing formulaic mobile-app developmental methodology.