• 한국해양공학회지
• /
• 제15권2호
• /
• pp.120-123
• /
• 2001

Despite the increasing necessity of accurate estimation of ring-stiffened cylinders'ultimate strength, the complex structural behavior of cylinders has made their design mainly depend on empirical formulas mostly based on limited test data rather than theoretical background. This paper has developed the imperfection method which enables the ultimate strength analysis of buckling-sensitive structures by combining two separate functions covered by common commercial finite element softwares, which are linear elastic buckling analysis and nonlinear stress analysis. Developed method was applied to two of the world most renowned softwares, MSC/NASTRAN and ABAQUS, for the analysis of ring-stiffened cylinders and unexpectedly big difference in their analysis results was found. This tells that many widely used commercial softwares have their different strong points and weak points and the choice of commercial software should be cautiously made after thorough inspection. This paper ends with some useful information about which of the two aforementioned softwares is more respectively for the linear elastic buckling analysis and the ultimate strength analysis of ring-stiffened cylinders.

• 한국학교수학회논문집
• /
• 제6권2호
• /
• pp.39-53
• /
• 2003

본 연구에서는 인터넷 환경에 적합한 동적기하 소프트웨어에 대하여 논의하였다. 먼저 동적기하 소프트웨어의 필요성을 살펴보고, 상용되고 있는 소프트웨어인 GSP, Cabri, Cinderella의 기능 및 특징을 비교하였다. 그리고 본 연구진에 의하여 국내 최초로 개발된 DRC(Digital Ruler and Compass)의 개발과정과 구조에 대하여 알아보고, 인터넷 환경에서 DRC를 활용한 학습 방안에 대하여 알아보고 이후의 발전전망에 대하여 논의하였다.

• ETRI Journal
• /
• 제32권5호
• /
• pp.646-656
• /
• 2010

A component is a reusable and replaceable software module accessed through its interface. Component-based development is expected to shorten the development period, reduce maintenance costs, and improve program reusability and the interoperability of components. This paper proposes a new robot software component platform in order to support the entire process of robot software development. It consists of specifications of a component model, component authoring tool, component composer, and component execution engine. To show its feasibility, this paper presents the analysis results of the component's communication overhead, a comparison with other robotic software platforms, and applications in commercial robots.

• Journal of Astronomy and Space Sciences
• /
• 제27권4호
• /
• pp.407-412
• /
• 2010

Software reusability is one of key factors which impacts cost and schedule on a software development project. It is very crucial also in satellite simulator development since there are many commercial simulator models related to satellite and dynamics. If these models can be used in another simulator platform, great deal of confidence and cost/schedule reduction would be achieved. Simulation model portability (SMP) is maintained by European Space Agency and many models compatible with SMP/simulation model interface (SMI) are available. Korea Aerospace Research Institute (KARI) is developing hardware abstraction layer (HAL) supported satellite simulator to verify on-board software of satellite. From above reasons, KARI wants to port these SMI compatible models to the HAL supported satellite simulator. To port these SMI compatible models to the HAL supported satellite simulator, simulation scheduler is preliminary designed according to the SMI standard.

• 한국항공운항학회지
• /
• 제22권4호
• /
• pp.81-86
• /
• 2014

In the development of an avionics system, there is a trend of using commercial-off-the-shelf(COTS) equipments in order to reduce the development cost and time. In this paper, we present an implementation of an aircraft mission computer using the objected oriented software and the COTS equipments. We execute the aircraft guidance software on the system, and measure the calculation time and the used memory. To compare the guidance capability of the software program, we implement the same software logic on DS1104 system. The guidance software program executed on two different systems resulted in the almost identical simulation.

• 인터넷정보학회논문지
• /
• 제9권3호
• /
• pp.119-128
• /
• 2008

상용의 소프트웨어를 사용하기 위해서 대부분의 소프트웨어 사용자는 그 소프트웨어를 구입하여야한다. 하지만 해당 소프트웨어에 대한 사용 시간이 길지 않은 경우, 그 소프트웨어 비용은 과다한 지출로 인식된다. 소프트웨어 임대 서비스는 이러한 경우 효과적인 대안일 수 있다. 소프트웨어 임대를 지원하기 위해서는 요금 부과 기법이 필요하다. 두 종류의 요금 부과 기법이 생각될 수 있다. 하나는 특정 기간 소프트웨어 사용에 대하여 일정한 요금을 부과하는 것이며 다른 하나는 실제 사용한 시간에 따라 요금을 부과하는 것이다. 이 논문에서는 소프트웨어의 실제 사용 시간에 따라 요금을 부과하는 기법을 제안한다 소프트웨어의 실제 사용 시간에 따라 요금을 부과하기 위하여 사용 시간을 정화하게 측정할 수 있는 기법을 고안하였다.

• Industrial Engineering and Management Systems
• /
• 제7권1호
• /
• pp.51-56
• /
• 2008

With growing demand for zero defects, predicting reliability of software systems is gaining importance. Software reliability models are used to estimate the reliability or the number of latent defects in a software product. Most reliability models to estimate the reliability of software in the literature are based on the development lifecycle stages. However, in the maintenance phase, the software needs to be corrected for errors and to be enhanced for the requests from users. These decrease the reliability of software. Software Reliability Growth Models (SRGMs) have been applied successfully to model software reliability in development phase. The software reliability in maintenance phase exhibits many types of systematic or irregular behaviors. These may include cyclic behavior as well as long-term evolutionary trends. The cyclic behavior may involve multiple periodicities and may be asymmetric in nature. In this paper, SGRM has been adapted to develop a reliability prediction model for the software in maintenance phase. The model is established using maintenance data from a commercial shop floor control system. The model is accepted to be used for resource planning and assuring the quality of the maintenance work to the user.

• 국제초고층학회논문집
• /
• 제5권2호
• /
• pp.95-103
• /
• 2016

One of the key problems in the design of high-rise commercial complex is how to guide reasonable pedestrian distribution in commercial space. In this study, pedestrian distribution in three high-rise commercial complexes in Shanghai and Hong Kong was studied using spatial configuration analysis software Space Syntax and quantification of physical elements in commercial spaces, such as functional attractiveness, entrances, escalators, level variations and passage width. Additionally, in an attempt to integrate functions with spatial integration and spatial depth, two combination variables, the spatial coefficient of function (IF) and spatial depth coefficient of function (F/D), were proposed. The results of the correlation analysis and multiple regression analyses reflected the following: (1) Regarding the influence on pedestrian distribution, there was a synergistic and complementary relationship between function and space; (2) The comprehensive flow distribution analytic model could successfully interpret flow distribution in high-rise commercial complexes and its R Square ranged up to about 70% in the three cases; (3) The spatial coefficient of function (IF) and spatial depth coefficient (F/D) could effectively integrate functions and spatial configuration, which could help close the gap between over-emphasis on function in commercial research and the lack of consideration of function in space-syntax analysis.

• Journal of Computing Science and Engineering
• /
• 제6권2호
• /
• pp.79-88
• /
• 2012

Power continues to be a driving force in central processing units (CPU) design. Most of the advanced breakthroughs in power have been in a realm that is applicable to workstation CPUs. Advanced power management systems will manage temperature, dynamic voltage scaling and dynamic frequency scaling in a CPU. The use of power management systems for microcontrollers and embedded CPUs has been modest, and mostly focuses on very large scale integration (VLSI) level optimizations compared to system level optimizations. In this paper, a dynamic frequency controlling (DFC) technique is introduced, to lay the foundation of a system level power management system for commercial microcontrollers. The DFC technique allows a commercial microcontroller to have minor modifications on both the hardware and software side, to allow the clock frequency to change to save power; results in this study show a 10% savings. By adding an additional layer of software abstraction at the interrupt level, the microcontroller can operate without having knowledge of the current clock frequency, and this can be accomplished without having to use an embedded operating system.

• 한국자동차공학회논문집
• /
• 제22권1호
• /
• pp.52-58
• /
• 2014

To improve the performance of clutch actuator of clutch-by-wire system for commercial vehicles, it is necessary to understand the driving characteristics of the system. To explain and predict the effects of driving characteristics on clutch characteristics, AMESim software is used. The simulation model of clutch-by-wire system is developed in the AMESim environments under the geometrical dimensions and driving mechanisms of the clutch-by-wire system, such as the rotation speed of the DC motor, the gear ratio of the reducer, the design parameters of the release fork, the coefficient of the clutch diaphragm spring, and so on. The results show that the theoretical analysis of the clutch-by-wire system for commercial vehicles using the AMESim software find out the driving characteristics of the clutch actuator, and predict the performance characteristics of the clutch-by-wire system.