• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.12
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• pp.201-209
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• 2009

In power plant operations, sensor values often exhibit erroneous values due to their failures or the intrusions of various noises. However, most of the power plant monitoring and fault diagnosis systems perform their tasks based on the assumptions that the collected sensor values are correct all the times. These assumptions, which are not valid, often lead to serious consequences such as power plant trips. In this paper, we propose a power plant sensor value validation technique that can utilize the relationships existing among the sensor values as the sensor redundancy. The proposed technique is applied to the flow meters installed along boiler feed water systems of a typical tubular type boiler thermal power plant and shows a good potential of future applications.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.534-537
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• 2006

Currently, The fast development which radio communication technique is creating new services from the industry sector which is various from convenient characteristic and the ease characteristic side. Specially, rise and development of the radio communication technique which is various from environment monitor ring field makes to be improved about sharp curtailment of establishment and logistics relation expense, and collection period of the data which occurs real-time from site, reliability and delivery characteristic. But continuous application and the success about the environment monitor ring field of radio communication technique will be able to trust And It is important to provide time information which is appropriate real-time. So this paper plans the sensor network based on environment measurement watch which applies a radio communication technique.

• Journal of Navigation and Port Research
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• v.33 no.1
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• pp.35-41
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• 2009

A waypoint tracking algorithm(WTA) is designed for Unmanned Surface Vehicle(USV) in which water-jet system is installed for propulsion To control the heading of USV for waypoint tracking, the steering nozzle of water-jet need, to be controlled. Firstly, target heading is calculated by using the position information of waypoints input from the land control center. Secondly, the command for the steering nozzle of water-jet is calculated in real time by using the heading and the rate-of-turn( ROT) from magnetic compass, In this study, in order to consider the drift angle due to external disturbance such as wind and wave, the course of ground( COG) can be used instead of heading at higher speed than a certain value, To test the performance of newly-designed WTA, the tests were carried out in actual sea area near Gwang-an bridge of Busan. In this paper, the sea trial test results from WTA are analyzed and compared with those from manual control and those from commercial controller.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.8
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• pp.2051-2056
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• 2014

This paper investigated the separation of magnetic signal from a ferro-magnetic object. The magnetic signals were ILM(induced longitudinal magnetization) and IVM(induced vertical magnetization), which were induced by earth magnetic field and PLM(permanent longitudinal magnetization) and PVM(permanent vertical magnetization), which were due to a permanent magnetization of the object, respectively. Magnetic signal separation was based on the fact that magnetization vector could be analyzed according to longitudinal and vertical directions. Also the influence of non-uniform magnetic field from a rectangular coil on the separation was examined. A military vessel with a size close to rectangular coil has more errors on the magnetic signal separation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.8
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• pp.1560-1566
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• 2017

Recently, accumulation of data on pig farm is enabled through the wide spread of smart pig farm equipped with Internet-of-Things based sensors, and various machine learning algorithms are applied on the data in order to improve the productivity of pig farm. Herein, multiple machine learning schemes are used to predict the water usage in pig farm which is known to be one of the most important element in pig farm management. Especially, regression algorithms, which are linear regression, regression tree and AdaBoost regression, and classification algorithms which are logistic classification, decision tree and support vector machine, are applied to derive a prediction scheme which forecast the water usage based on the temperature and humidity of pig farm. Through performance evaluation, we find that the water usage can be predicted with high accuracy. The proposed scheme can be used to detect the malfunction of water system which prevents the death of pigs and reduces the loss of pig farm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.6
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• pp.3672-3679
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• 2015

The heat generated by electrical components during train operation was estimated by measuring the wall temperature in a locomotive, as well as the temperature and speed of the air entering from the outside and then returning to the outside. The temperatures of the electrical components and wall surface in a high-speed train were measured using an infrared camera. The heat generated by the electrical components was exhausted to the outside through a duct installed on the ceiling of the high-speed train. Thus, the temperature and speed of this exhaust air were measured, as well as those of the air entering the locomotive from the outside. The temperatures at the surfaces of the electrical components and walls in the locomotive were also measured using an attachment-type temperature sensor. In addition, the measurement results were applied to analyze how the heat characteristics of the electrical components were affected by the train operation.

• International Journal of Highway Engineering
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• v.12 no.4
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• pp.157-164
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• 2010

This research was conducted to analyze the behavior of Single-PTAS (Single Post-Tensioned Approach Slab) under tensioning and environmental loads by performing field tests when the demonstration Single-PTAS was being constructed. The temperature measurement sensors were installed at different depths, and the displacements in the approach slab under environmental loads and tensioning were measured using displacement transducers. As an experimental result, an abrupt change in the longitudinal displacement due to tensioning was not observed. The daily temperature change in the approach slab was negligible where the depth is over about 35cm. The temperature gradient in the approach slab adjacent to bridge was smaller than that adjacent to pavement. The patterns and magnitudes of vertical displacements were directly related to the temperature gradient at the measuring location. The behavior of Single-PTAS was very similar to that of concrete pavement. Therefore, a new design methodology for approach slabs is needed to include the pavement concept and to overcome drawback of current design procedures based on the simple beam concept.

• International Journal of Highway Engineering
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• v.12 no.3
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• pp.147-154
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• 2010

In post-tensioned concrete pavement(PTCP), one of the most important design variables is the initial joint width, in addition to the tensioning spacing. The joint width between PTCP slabs directly affects noise and ride quality. If the joint width is too wide, noise increases and ride quality decreases. If the initial joint width is too narrow, on the other hand, under high temperature, PTCP slabs can blow up, or failures near the joint can occur due to excessive compressive stresses. This study was conducted to determine the optimal initial joint width of PTCP and to investigate the joint width behavior under temperature changes. The experiments were performed using one-year-old PTCP slabs. The concrete temperatures were measured using the temperature measurement sensors installed at various depths. The joint widths were measured using vernier-calipers at different times of a day and the relationship between the joint width and temperature was analyzed. From this study, the design methodology to determine the optimal initial joint width of PTCP could be proposed.

• Journal of the Korean Vacuum Society
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• v.22 no.4
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• pp.175-180
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• 2013

We developed the contamination prevention module of an optical window for an In-Situ Particle Monitor (ISPM) system. the core part of the module is the generator of an ultrasonic wave and the module is to remove particles stuck to the window by the transfer of the wave force to the window surface. In order to enhance transfer efficiency of the waves the frequency of the ultrasonic wave was optimized and a low impedance material (plexiglass) and a soft sealing material (Si rubber) were used. The ISPM with the developed module was installed at the exhaust line of a BPSG CVD equipment and the effect of the module was verified.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.711-717
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• 2017

Startability and harmful emissions are the main issues in diesel engine development under cold conditions. The characteristics of combustion with multiple injection were investigated under cold start conditions. For quantitative analysis, the in-chamber pressure profile was measured and combustion visualization using direct imaging was accomplished. With multiple injection, the peak in-chamber pressure and heat release rate were increased compared to single injection. In addition, the period of flame luminosity detection was shortened using multiple injection. Combustion by main injection was improved with an increase in heat released by pilot combustion when the pilot injection quantity was increased. Finally, an increase in injection pressure also showed the possibility of combustion improvement. On the other hand, an increase of in the pilot injection quantity and injection pressure can cause an increase in harmful emissions, such as HC and CO due to wall wetting. Therefore, more sensitive calibration will be needed when applying a multiple injection strategy under cold start conditions.