• Journal of Information Processing Systems
• /
• v.2 no.3 s.4
• /
• pp.159-162
• /
• 2006

Wireless LANs are becoming more widespread because of the rapid advance of wireless technologies and mobile computers. In this paper, we present the design and implementation of a system to help mobile users to select the most competent AP. By monitoring the network traffic of APs within the local LAN in real time, this system offers the mobile user the network utilizations, locations, and signal strengths of APs online. Based on the information, the user can select a competent AP with a high wireless bandwidth. Finally, we verified the accuracy of monitoring and calculating with regard to the utilizations of APs through real experiments.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.516-516
• /
• 1993

This study was carried out to develop an environment -controlled vegetable growth system. The control objects considered were light, temperature, humidity, $CO_2$ concentration and the conditions of nutrient solution such as pH , EC and dissolved oxygen. A monitoring system was developed to measure the above environmental factors, fresh weight and $CO_2$consumption rate. The overall performance of the developed system was reasonably acceptable for vegetable growth. by the lettuce growing test, it was shown that the developed system had a good repeatability , and the growth responses could be measured satisfactorily.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.23 no.7
• /
• 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.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.406-410
• /
• 2009

Power facilities of urban rail transit substation is deterioration, and endurance limitation is coming, so urban rail transit facilities should take any necessary measure for maintenance and repair. In this paper proposes online monitoring system using the wireless communications for the urban rail transit. This system is constructed various departments; such as sensor, measurement, data communication, host computer, and power departments. It is designed to collect and save AI (Analog Input) information of the power facilities, and to analyze and display them. As a result, it is possible to prevent from any unexpected power cuts and monitor my abnormalities in real time, and to collect accumulated data for creating a better management system.

• Journal of the Optical Society of Korea
• /
• v.20 no.6
• /
• pp.770-777
• /
• 2016

It has been a challenge for researchers to accurately measure high temperature creep strain online without damaging the mechanical properties of the pipe surface. To this end, a noncontact method for measuring high temperature strain of a main steam pipe based on digital image correlation was proposed, and a system for monitoring of high temperature strain was designed and developed. Wavelet thresholding was used for denoising measurement data. The sub-pixel displacement search algorithm with curved surface fitting was improved to increase measurement accuracy. A field test was carried out to investigate the designed monitoring system of high temperature strain. The measuring error was less than $0.4ppm/^{\circ}C$, which meets actual measurement requirements for engineering. Our findings provide a new way to monitor creep damage of the main steam pipe of a boiler of an ultra-supercritical power plant in service.

• Nuclear Engineering and Technology
• /
• v.48 no.6
• /
• pp.1404-1411
• /
• 2016

Pipe wall thinning in the secondary piping system of a nuclear power plant is currently a major problem that typically affects the safety and reliability of the nuclear power plant directly. Regular in-service inspections are carried out to manage the piping system only during the overhaul. Online thickness monitoring is necessary to avoid abrupt breakage due to wall thinning. To this end, a transducer that can withstand a high-temperature environment and should be installed under the insulation layer. We propose a thin plate type of embedded ultrasonic transducer based on magnetostriction. The transducer was designed and fabricated to measure the thickness of a pipe under a high-temperature condition. A number of experimental results confirmed the validity of the present transducer.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.36 no.3
• /
• pp.175-180
• /
• 2016

Nondestructive evaluation for material health monitoring is important in aerospace industries. Composite laminates are exposed to heat cyclic loading and humid environment depending on flight conditions. Cyclic heat loading and moisture absorption may lead to material degradation such as matrix breaking, debonding, and delamination. In this paper, the moisture absorption ratio was investigated by measuring the Lamb wave velocity. The composite laminates were manufactured and subjected to different thermal aging cycles and moisture absorption. For various conditions of these cycles, not only changes in weight and also ultrasonic wave velocity were measured, and the Lamb wave velocity at various levels of moisture on a carbon-epoxy plate was investigated. Results from the experiment show a linear correlation between moisture absorption ratio and Lamb wave velocity at different thermal fatigue stages. The presented method can be applied as an alternative solution in the online monitoring of composite laminate moisture levels in commercial flights.

• Laser Solutions
• /
• v.11 no.2
• /
• pp.33-38
• /
• 2008

Laser micromachining has increasingly been adopted in various advanced industries where the high-precision machining of large-area, high-density and multi-layered components is in a strong demand. To effectively meet the requirements, the laser micromachining process must be carefully monitored. In order to facilitate the development of a new laser micromachining process and/or a new system, we have fabricated a UV laser micromachining platform that is equipped with optical modules for monitoring the process online. They include a laser power stabilizing module, a module for laser-induced breakdown spectroscopy, and an auto-focusing module.

• Proceedings of the Membrane Society of Korea Conference
• /
• 1994.04a
• /
• pp.29-32
• /
• 1994

The increasing environmental risks exert strong demands for the knowledge of environmentally significant compounds and the reduction of such compounds on the earth. The risk reduction can, in principle, be most effectively achieved by minimizing the formation of environmental pollutants, by-products in many cases, during processes in factories, power plants and other sources. This can be done by on-line, real time monitoring the formation of pollutants at the moment when they are formed, and thereby through the feed-back control of the process.

• Proceedings of the Korea Information Processing Society Conference
• /
• 2010.11a
• /
• pp.421-424
• /
• 2010

수업역량향상을 위해 최근 각 학교별 수업행동분석실을 갖추고 있는 추세이다. 하지만 수업행동분석실은 많은 비용, 시연자와 분석자에 대한 시공간적 제약, 비효율적인 피드백 방법, 사후 자가분석 어려움 등 많은 문제가 존재한다. 본 논문에서는 온라인 수업행동분석시스템 설계를 통해 물리적 공간 설치의 비용을 절감하고 전문가 참여를 위한 시간적 제약을 극복할 수 있는 방법을 제안하였다.