• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.810-815
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• 2010

Since a long time ago, many railway engineers analyze and discuss the interface between the sub-system of railway, such as a wheel/rail interface, pantograph/catenary interface etc. The verifying of the system interface could help to achive the optimized performance and safety of the railway system considering that the railway system is constructed by various engineerings, such as civil, mechanical, electrical, etc. A rolling stock with distributed drive system, which will be developed by HEMU-400x project, is capable of running on high speed line and conventional line in Korea. To verify the performance of rolling stock, test run will be done with revenue service line. And the test items of the system interface have to be selected to verify a functional compatibility and physical force between rolling stock and infrastructure. In this paper, the authors will indicates the test items to verify system interface. To achive the conclusion, the authors analyze a specification of the development train and the design value of Seoul-Busan high speed line, which will be used for testing of the development train, and also, study the various case of high speed train commissioning.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.486-490
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• 2004

Programmable logic controller (PLC) is widely used in manufacturing system or process control. This paper presents the design of a 32-bit microprocessor for a sequence control using an Application Specification Integrated Circuit (ASIC). The 32-bit microprocessor was designed by a VHDL with top down method; the program memory was separated from the data memory for high speed execution of 274 specified sequence instructions. Therefore it was possible that sequence instructions could be operated at the same time during the instruction fetch cycle. And in order to reduce the instruction decoding time and the interface time of the data memory interface, an instruction code size was implemented by 32-bits. And the real time debugging as single step run, break point run was implemented. Pulse instruction, step controller, master controllers, BIN and BCD type arithmetic instructions, barrel shit instructions were implemented for many used in PLC system. The designed microprocessor was synthesized by the S1L50000 series which contains 70,000 gates with 0.65um technology of SEIKO EPSON. Finally, the benchmark was performed to show that designed 32-bit microprocessor has better performance than Q4A PLC of Mitsubishi Corporation.

• 대한전자공학회논문지TC
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• 제45권2호
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• pp.6-12
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• 2008

본 논문에서는 상향 링크 케이블 모뎀 시스템에 대한 동기화 방법에 대하여 제안하였다. 상향 링크의 케이블 모뎀 시스템은 DOCSIS(data over cable service interface specification) 규격에 의해 정해져 있으며, 이에 맞는 동기화 방법에 관하여 연구하였다. 케이블 모뎀은 버스트 모드로 동작하며 시 분할 다중 접속(time division multiple access, TDMA) 버스트 포맷을 사용한다. 버스트 포맷은 프리앰블과 데이터 구간으로 나뉜다. 본 논문에서는 프리앰블을 이용한 프레임 동기, coarse 타이밍 동기, 반송파 주파수 동기, 반송파 각 동기 방법을 연구하였으며, 프리앰블로 이용할 시퀀스로 correlation 특성이 우수한 CAZAC(constant envelope zero-autocorrelation) 시퀀스를 이용하였다. 또한 타이밍 드리프트가 존재하는 경우와 나머지 주파수 오프셋이 주는 영향을 고려하여 데이터 구간에서 심벌 타이밍 동기방식과 주파수 각 오프셋 추정박식을 채택하여 시스템을 구성하였고, 이를 컴퓨터 실험 결과를 이용하여 성능을 검증하였다.

• Computers and Concrete
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• 제27권2호
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• pp.153-162
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• 2021

This paper aims to simulate the isotropic elastic damage theory of Liu Jun (2012) using the self-programmed UMAT subroutine in the interface of ABAQUS. Liu Jun (2012)'s method based on the mechanic theory can not be used interactively with the currently commonly used finite element software ABAQUS. The advantage of this method in the paper is that it can interact with ABAQUS and provide a constitutive program framework that can be modified according to user need. The model retains the two scalar damage variables and the corresponding two energy dissipation mechanisms and damage criteria for considering the tensile and compressive asymmetry of concrete. Taking C45 concrete as an example, the relevant damage evolution parameters of its tensile and compressive constitutive model are given. The study demonstrates that the uniaxial tensile stress calculated by the subroutine is almost the same as the Chinese Concrete Design Specification (GB50010) before the peak stress, but ends soon after the peak stress. The stress-strain curve of uniaxial compression calculated by the subroutine is in good agreement with the peak stress in Chinese Concrete Design Specification (GB50010), but there is a certain deviation in the descending stage. In addition, this paper uses the newly compiled subroutine to simulate the shear bearing capacity of the shear key in a new structural system, namely the open-web sandwich slab. The results show that the damage constitutive subroutine has certain reliability.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제7권4호
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• pp.834-848
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• 2013

To effectively use these functions many kinds of human-phone interface are used such as touch, voice, and gesture. However, the most important touch interface cannot be used in case of hand disabled person or busy both hands. Although eye tracking is a superb human-computer interface method, it has not been applied to smartphones because of the small screen size, the frequently changing geometric position between the user's face and phone screen, and the low resolution of the frontal cameras. In this paper, a new eye tracking method is proposed to act as a smartphone user interface. To maximize eye image resolution, a zoom lens and three infrared LEDs are adopted. Our proposed method has following novelties. Firstly, appropriate camera specification and image resolution are analyzed in order to smartphone based gaze tracking method. Secondly, facial movement is allowable in case of one eye region is included in image. Thirdly, the proposed method can be operated in case of both landscape and portrait screen modes. Fourthly, only two LED reflective positions are used in order to calculate gaze position on the basis of 2D geometric relation between reflective rectangle and screen. Fifthly, a prototype mock-up design module is made in order to confirm feasibility for applying to actual smart-phone. Experimental results showed that the gaze estimation error was about 31 pixels at a screen resolution of $480{\times}800$ and the average hit ratio of a $5{\times}4$ icon grid was 94.6%.

• Advances in aircraft and spacecraft science
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• 제2권2호
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• pp.217-232
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• 2015

To prevent over-testing of the test-item during random vibration testing Scharton proposed and discussed the force limited random vibration testing (FLVT) in a number of publications. Besides the random vibration specification, the total mass and the turn-over frequency of the load (test item), $C^2$ is a very important parameter for FLVT. A number of computational methods to estimate $C^2$ are described in the literature, i.e., the simple and the complex two degrees of freedom system, STDFS and CTDFS, respectively. The motivation of this work is to evaluate the method for the computation of a realistic value of $C^2$ to perform a representative random vibration test based on force limitation, when the adjacent structure (source) description is more or less unknown. Marchand discussed the formal description of getting $C^2$, using the maximum PSD of the acceleration and maximum PSD of the force, both at the interface between load and source. Stevens presented the coupled systems modal approach (CSMA), where simplified asparagus patch models (parallel-oscillator representation) of load and source are connected, consisting of modal effective masses and the spring stiffness's associated with the natural frequencies. When the random acceleration vibration specification is given the CSMA method is suitable to compute the value of the parameter $C^2$. When no mathematical model of the source can be made available, estimations of the value $C^2$ can be find in literature. In this paper a probabilistic mathematical representation of the unknown source is proposed, such that the asparagus patch model of the source can be approximated. The chosen probabilistic design parameters have a uniform distribution. The computation of the value $C^2$ can be done in conjunction with the CSMA method, knowing the apparent mass of the load and the random acceleration specification at the interface between load and source, respectively. Data of two cases available from literature have been analyzed and discussed to get more knowledge about the applicability of the probabilistic method.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.523-526
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• 1998

In an ongoing project at ETRI-CSTL, A debugger for distributed programs that run on a varied collection of machines is being built. To build such debugger, a clientserver model is incorporated. This strategy enables us to provide a unified user interface and isolate debugger core from the user interface. Several debugging servers running on a diverse set of platforms permit the implementation of a distributed debugger for heterogeneous environment, and the single debugging client provides unified debugging concept and graphical user interface over various servers. Also, the precise specification of the interaction protocol between the client and server facilitates client to be paired with a variety of server implementantations. This paper describes the design and implementation of our debugger, concentrating on the system architecture.

• 산업경영시스템학회지
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• 제26권2호
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• pp.23-28
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• 2003

This research explains visualization of diagnostic system of 3D CAD data, IGES (Initial Graphics Exchange Specification), by using JNI(Java Native Interface) to connect between C++ and Java programming. The diagnostic system is to analyze IGES clearly by identifying errors and anomalies with respect to the diagnosis of geometry and topology of entities. The output of the system is IGES file including . error information which can be visualized with different colors by several commercial visualization systems. The paper focuses on the visualization of the result IGES which can be extended to web based application over internet.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.1129-1132
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• 1999

This paper deals with the design and implementation of an Ethernet-based communication protocol to be used in PC-based I/O interface systems. Recently, the performance of PC systems is being highly improved and Ethernet is used as the stable communication network over the world. We develop a new protocol driver with the capability of accessing Ethernet directly using NDIS(Network Driver Interface Specification), the network interface standard of Windows O.S. in PC, and install it at the application layer of the protocol structure. Its major roles are the supplement of CSMA/CD algorithm, the effective use of the long data frame of Ethernet, and the real-time transmission of data frames. This paper represents the possibility of the real-time control network and systems based on PCs and Ethernet.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(1)
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• pp.21-24
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• 2001

Bluetooth wireless technology is a publicly available specification proposed for Radio Frequency (RF) communication for short-range and point-to-multipoint voice and data transfer. It operates in the 2.4GHz ISM(Industrial, Scientific and Medical) band and offers the potential for low-cost, broadband wireless access for various mobile and portable devices at range of about 10 meters. In this paper, we describe the structure and the test results of the bluetooth baseband module we have developed. This module has a UART interface for HCI and a audio codec for voice. The interface between controller and this module supports common control interface. An FPGA implementation of this module is tested for file and bit-stream transfers between PCs.