• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.375-378
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• 1996

Robot control software is a hard real-time system that must output the planned trajectory points within an explicit short time period. In this paper, we present a design and implementation method for robot control software using commercial real-time operating systems, RTKemel 4.5. Therefore, various robot motions, efficient user interface, and system failure check are easily implemented by using multitasking function, intertask communication mechanism, and real-time runtime libraries of RTKernel. The performance analysis of commercial real-time operating system for robot control is presented based on Timed Petri net(TPN) and we can use these results to design an optimal system.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2006.11a
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• pp.393-396
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• 2006

This paper presents the characteristics of the performance parameters of dual mode(ramjet-scramjet combined) engine, inlet and combustor for wide range of flight Mach number, resulted from the analysis of its operating limitations. The transitional-critical flight Mach number from ramjet to scramjet and the performance of two types of combustors, such as constant pressure- and constant area- combustor, are conceptually evaluated.

• 한국벤처창업학회:학술대회논문집
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• 2006.11a
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• pp.61-85
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• 2006

The Purpose of this study is to prove empirically the relationship between ventures' technology valuation and performance, while considering the uniqueness of Korean firms. We use technology valuation index, marketability valuation index, business valuation index as ex-ante independent variables, use firm's performance(sales, asset, operating income ratio, net income ratio etc) as ex-post dependent variables. Parametric analysis such as Paired T-test, ANOVA are applied in this paper. The results of Empirical analysis is summarized as follows. Firstly, operating income ratio and net income ratio are different in portfolios classified by technology valuation index. Secondly, the growth rate of operating income is different in portfolios classified by technology valuation index. Finally, this study has shown that technology valuation index has possibility which it use the predictive variables of ventures' performances.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.194-197
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• 2011

네트워크 가상화 기술은 하드웨어적인 제약사항을 완화시켜 다양한 서비스를 제공하는 네트워크 토폴로지를 구성할 수 있도록 하는 기술로써, 미래 인터넷 환경과 클라우드 컴퓨팅을 지원 할 수 있는 기술이다. 또한 가상화된 네트워크를 제공하기 위한 소프트웨어 기반의 라우터는 하드웨어의 라우터보다 상대적으로 비용이 저렴하고 높은 유연성과 유지 보수성을 갖는다. 소프트웨어 기반의 라우터를 통하여 물리적인 네트워크 위에서 각기 다른 서비스를 제공하는 다양한 가상 네트워크들을 공존하게 하고, 다양한 서비스를 효과적으로 제공하기 위해서는 각 네트워크의 독립성과 서비스의 품질 제어가 필요하다. 이 논문에서는 네트워크 가상화를 통하여 각 가상 네트워크들의 독립성을 보장하는 Network Isolation 기술과 QoS 보장을 위한 동적인 대역폭 조절을 제공하는 Performance Isolation 기술을 제안한다. 이를 통하여 기존 하드웨어 라우터에서는 제공되지 않은 높은 유연성 과 다양한 응용, 비용의 절감, 유지 보수의 용이성 등을 제공 할 수 있다.

• Progress in Superconductivity and Cryogenics
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• v.4 no.2
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• pp.58-62
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• 2002

The purpose of this study is to analyze the charging gas effect on the resonance and performance characteristics of the linear compressor for small scale FPFD Stirling refrigerator. To ensure high performance of FPFD type Stirling refrigerator, the operating frequency of the refrigerator should be around the natural frequency of compressor. The gas spring effect which is induced from Pressure change in cylinder due to motion of pistons has significant effect on the natural frequency of the compressor. The numerical results show the linear compressor has high natural frequency when the charging pressure of working fluid is high and the stroke of compressor, current, input power and efficiency of compressor were shown with different operating conditions.

• Knowledge Management Research
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• v.4 no.1
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• pp.21-33
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• 2003

The Purpose of this study is to prove empirically the relationship between technology valuation and performance in Ventures, while considering the uniqueness of Korean firms. We use technology score, marketability score, business attractiveness score as ex-ante independent variables, use firm's performance(sales, asset, operating income ratio, net income ratio etc) as ex-post dependent variables. Parametric analysis such as Paired T-test, ANOVA are applied in this paper. The results of Empirical analysis is summarized as follows. Firstly, operating income ratio and net income ratio are different in portfolios classified by technology score. Secondly, the growth rate of operating income is different in portfolios classified by technology score. Finally, this study has shown that technology score has possibility which it use the predictive variables of firm performances.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.3
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• pp.139-148
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• 2011

As the architecture of automotive software is complicated and LOC of software increases, there is an increasing demand for standard operating system. OSEK/VDX defines an industry standard for automotive operating system and middleware. This paper introduces an implementation of RTOS(OSCAR-OSEK) based on OSEK/VDX standard. For better speed of scheduling, we suggest a new method for ready queue implementation considering the characteristic of automotive application software. Also we introduce a method for improving the portability of RTOS on various MCUs. And, we show OSCAR-OSEK implementation and performance test results.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.11-16
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• 2023

EtherCAT is an Ethernet-based fieldbus system standardized in IEC 61158 and SEMI, and widely used in the fields of factory automation, semiconductor equipment and robotics. In this paper, without operating system, we have implemented an EtherCAT master with an open source EtherCAT master stack SOEM on STM32 Nucleo-144 board with an STM32F767 microcontroller. And its jitter performance has been evaluated at the output of the network port to include all the effects of the entire system in the results. The results show that the implemented EtherCAT master has precise control performance for control frequencies from 1KHz to 8KHz and relatively superior jitter performance compared to the EtherCAT masters with real-time patched Linux operating system.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.499-500
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• 2007

The various sensor nodes operating in Ubiquitous Sensor Network environment require the tiny Operating System different from the existing pc-type operating system because of their characteristics. Also Sensor Network operating system needs to support the rapid event handling which sensor node must implement. In this paper, we overcome the drawbacks of the existing sensor network operating system and propose the new kernel which is designed to assist developer to construct event-central operating system entirely. We also evaluate the performance of the super tiny sensor network operating system based on proposed kernel, comparing with that of the existing sensor network operating system.

• Journal of the Korean Electrochemical Society
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• v.13 no.4
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• pp.283-289
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• 2010

A two-dimensional isothermal model has been employed for numerical simulations of a high temperature hydrogen fuel cell with proton exchange membrane. The model is validated with existing experimental data and used for examination on the effects of various operating conditions on the fuel cell performance. The present numerical results show that the cell performance increases with increasing exchange current density, ion conductivity of the membrane, inlet gas flow rate as well as operating pressure. Also, higher porosity of gas diffusion layer (GDL) results in higher cell performance due to enhancement of the diffusion through the GDL, where the cathode GDL porosity more influences on the performance as compared with the anode one.