• Structural Engineering and Mechanics
• /
• 제36권2호
• /
• pp.129-147
• /
• 2010

This study deals with the viability of using a designed geometrical model consists of plane, polar coordinates (PC) and span length in the determination of bridges deformation. The data of a Tianjin Yonghe bridge located in the southern part of China as collected by RTK-DGPS technique and Accelerometer were used in the analysis. Kalman filter and fast Fourier transformation (FFT) analyses were used to determine the frequency. The results indicate that the designed plane and PC geometrical model are easy to calculate the long-time structural deformation monitoring. In addition, the observed frequency using GPS with the rate of 20 Hz doesn't give correction natural frequency of the observation structures.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제53권3호
• /
• pp.168-174
• /
• 2004

On-line monitoring system(OMS) has been developed for the pumped storage generator/motor The OMS is applied to diagnosis of the PD(partial discharge) activity of stator insulation, the shorted-turn of rotor winding and the variation of the air-gap between stator and rotor. The OMS consists of DAS(data acquisition system), main server system, gateway and display PC. The DAS measures the PD, the shorted-turn and air-gap from three sensors installed on the generator/motor. The gateway controls the data which sent by DAS. The main server system saves the data, analyzes the data and conducts the diagnostic algorithm. The display PC shows the diagnostic results of partial discharge, shorted-turn and air-gap. Field tests were conducted using PDA(partial discharge analyzer). The results of the OMS and PDA measurements can be directly correlated with normalized quantity number(NQN), PD magnitude(Qm) and PD pattern.

• 조명전기설비학회논문지
• /
• 제23권7호
• /
• pp.75-80
• /
• 2009

In this study, a Web server was constructed using LabVIEW's DataSocket, which makes possible acquisition, analysis, and saving in real time. The output value of the optical current sensor at the web server PC was measured and the output value was displayed using the Web browser of the client PC. DataSocket by LabVIEW makes the construction of a Web server easier than other languages and is compatible with other application programs. An optical current sensor was composed using a 1310 [nm] laser diode, and 9/125 [${\mu}m$] standard single mode optical fiber and was created to be a close type sensor. Data measurement using Web servers has the advantage of monitoring electric power systems at a great distance and can fuse IT technology and electric power systems. Also, this measurement uses inexpensive mounting and programming when compared to existing measurement equipment allowing the construction of a measurement system in any situation or surrounding.

• 한국측량학회지
• /
• 제15권2호
• /
• pp.185-193
• /
• 1997

While close range photogrammetry has been widely applied for static deformation analysis, video cameras have many characteristics that make them the sensors of choice for dynamic analysis of rapidly changing situations. They also have limitations. The aim of this research is to explore the potential of a video system for monitoring dynamic objects. A pilot system consists of two camcorders, VCR, and PC with frame grabber. To estimte the performance of this system for moving objects, a car was imaged covering several phases when starting to drive. The sequential images of a moving car were recorded on VCR. 15 images per second were digitized in an off-line mode by frame grabber. The image coordinates of targets attached to the rear bumper of a car were acquired by IDRISI, and the object coordinates were derived based on DLT. This research suggests that home video cameras, PC, and photogrammetric principles are promising tools for monitoring of the moving objects and vibrations as well as other time dependent situations.

• 정보보호학회논문지
• /
• 제7권3호
• /
• pp.3-10
• /
• 1997

Computer viruses are increasing in number and are continually intellectualized as well. To cope with this problem, anti-virus tools such as a scanner and the monitoring program have been developed. But it is not guaranteed that these softwares will work in safety under MS-DOS' control. If the virus is run first, it can avoid the monitoring of anti-virus software or even can attack the anti-virus software. Therefore, anti-virus programs should be run before the system is infected. This paper presents a new PC starting mechanism which allows the PC system to start from a clean state after booting. For this mechanism, we build a new disk file system different from DOS' file system, and manage the two file systems heterogeneously. Our system is strong against boot viruses and recovers from infections automatically.

• 전기학회논문지P
• /
• 제53권4호
• /
• pp.183-189
• /
• 2004

In this paper, an automatic welding system is developed. In the developed system, an automatic welding system is remotely controlled by a portable panel PC. Additional, the DB system such as the operating condition and control data of automatic welding carriage is developed by ATMega128. Therefore, the developed system can overcome the restriction of operating condition, and reduce the weight of welding system and the risk of safety. The effectiveness of the developed system has been verified by the simulation and experimental results respectively.

• 한국정밀공학회지
• /
• 제16권7호
• /
• pp.85-93
• /
• 1999

In this study, PC-based slicing machine and driving software were constructed for the purpose of automation of semi-conductor cutting process. The biggest feature of software is variation of parameter and include data base, signal monitoring, error report, corresponding action or automatic motion planing. Parameters were drawn and algorithms were developed to make software by GUI interface. The cutting experiment was done for sampled wafer to see the effectiveness of the soft automation. From the experimented and implemented results, it is shown that parameters for automation of slicing process could be drawn, then its algorithms constructed. It could be considered what is the merit of this slicing machine by comparing the PC-based and the NC-based.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2002년도 추계학술대회 논문집
• /
• pp.636-640
• /
• 2002

In contrast to conventional CNC, PC-NC opens a new era for machine tools to be more intelligent. For instance, machine tool with PC-NC can be a machine agent system with capability of reacting autonomously to changing operating conditions. This paper introduces a concept of intelligent machine agent system, composed of machine agent and cell manager. Machine agent performs the functions such as process monitoring, diagnosis, maintenance management, condition assessment and schedule negotiation, while cell manager coordinates the negotiation process among multiple machine agents.

• 한국정보통신학회논문지
• /
• 제11권1호
• /
• pp.34-39
• /
• 2007

오늘날 인터넷이 활성화됨에 따라 내 외적 환경에 대한 보안의 필요성이 나날이 강조되고 있다. 특히 최근에는 개별 PC를 통한 메신저의 사용과 P2P 응용이 보편화되어 인터넷상의 개별 호스트에 대한 보안과 관리가 매우 중요하게되었다. 따라서 본 논문에서는 윈도우 기반의 개인 PC를 포함한 네트워크 상의 호스트에서도 외부의 접근 제어나, 패킷의 정보, 로그파일 기록, 모니터링을 이용하여 실시간으로 네트워크 상의 호스트의 상태를 관리, 파악하는 호스트 기반의 접근제어 시스템을 설계 및 구현방법을 제시하였다.

• Structural Monitoring and Maintenance
• /
• 제5권1호
• /
• pp.79-92
• /
• 2018

The evaluation theory of reliability, availability, maintainability and safety (RAMS) as a mature theory of state evaluation in the railway engineering, can be well used to the evaluation, management, and maintenance of complicated structure like the long-span bridge structures on the high-speed railway. Taking a typical steel-truss arch bridge on the Beijing-Shanghai high-speed railway, the Nanjing Dashengguan Yangtze River Bridge, this paper developed a new method of state evaluation for the existing steel-truss arch high-speed railway bridge. The evaluation framework of serving state for the bridge structure is presented based on the RAMS theory. According to the failure-risk, safety/availability, maintenance of bridge members, the state evaluation method of each monitoring item is presented. The weights of the performance items and the monitoring items in all evaluation levels are obtained using the analytic hierarchy process. Finally, the comprehensive serving state of bridge structure is hierarchical evaluated.