• Fire Science and Engineering
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• v.21 no.3
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• pp.97-103
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• 2007

This experimental study showed the tracking characteristics of contaminated insulating materials. To analysis tracking characteristics, IEC 60112 was used. As the results of this study, the tracking characteristics of contaminated insulating materials showed as followings: (a) Comparative tracking index (CTI) of contaminated insulating material was lower than non-contaminated one. (b) First carbonized growth time and track growth time of contaminated insulating materials was faster than non-contaminated.

• Fire Science and Engineering
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• v.33 no.2
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• pp.30-38
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• 2019

Tracking, which is one of the main causes of electrical fires, is perceived as a physical phenomenon of electrical discharge. Hence tracking should be explained based on electric field analysis, conduction path by electron generation, and gas discharge physics. However, few papers have considered these details. This paper proposes a tracking mechanism including their effects on tracking progress. In order to prove this mechanism, a tracking experiment, an electric field analysis for the carbonization evolution model, and an explanation of the tracking process by gas discharge physics were conducted. From the tracking experiment, the current waveforms were measured at each stage of the tracking progress from corona discharge to tracking breakdown. The electric field analysis was carried out in order to determine the electric field on the surface of a dry-band and the high electric field region for electron generation during the generation and progress of carbonization. In this paper, the proposed tracking mechanism consisted of six stages including electron avalanche by corona discharge, accumulation of positive ions, expansion of electron avalanche, secondary electron emission avalanche, streamer, and tracking by conductive path. The pulse current waveforms measured in the tracking experiment can be explained by the proposed tracking mechanism. The results of this study will be used as the technical data to detect tracking phenomenon, which is the cause of electric fire, and to improve the proof tracking index.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.1
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• pp.1-7
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• 2004

This paper describes the carbonization characteristics of a phenolic resin deteriorated by tracking under the environment of a fire. In the experiment, a liquids droplet of 1[％] NaCl was dripped on the phenolic resin to cause a tracking with 110[V], 220[V] voltages applied. It can be addressed from the experimental results that when an insulator is carbonized by an external fire, its structure is amorphous. If an insulator is carbonized by electrical cause, on the other hand, its structure would be crystalline. In order to observe the surface change of the phenolic resin, the tracking process was analyzed by using SEM. In the case that the materials are carbonized under heat or fire, the exothermic peak appears around 500[$^{\circ}C$]. This is one of the important factors to determine the cause of fires. As a result of DTA, the exothermic peaks of an untreated sample showed at 333.4[$^{\circ}C$], 495.7[$^{\circ}C$] but those of a sample deteriorated by tracking appeared at 430.6[$^{\circ}C$], 457.6[$^{\circ}C$] in a voltage of 110[V], and at 456.2[$^{\circ}C$], 619.7[$^{\circ}C$] in a voltage of 220[V]. It is possible, therefore, to distinguish a virgin sample from carbonized samples(graphite) by the exothermic peak.

• Journal of the Korea Institute of Military Science and Technology
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• v.27 no.4
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• pp.446-456
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• 2024

This paper addresses a novel approach to performance enhancement of the naval gun fire control system(FCS) by using the projectile tracking filter without any distortion of radar measurements. Under the assumption that the maneuvering between the projectile and the ship equipped with the radar is not quite large, this method is based on the concept of polar-coordinate target tracking, which separates the range estimation filter and the direction cosine estimation filter. Note that using polar-coordinates allows tracking to be performed in the same coordinate system from which the radar line-of-sight(LOS) measurements are obtained, unlike the conventional tracking process in Cartesian. Also, it is easy to implement in real-time and guarantees consistent estimates due to its linear filter structure. With the help of the above method, therefore, the proposed filter is able to improve the overall performance of FCS which requires stability of projectile estimates within a short engagement time. The effectiveness of the presented scheme is validated through computer simulations.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.305-306
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• 2012

• Fire Science and Engineering
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• v.30 no.6
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• pp.99-104
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• 2016

In animal and plant facilities, dust samples were collected from cattle sheds, pigsties and hen-houses, which have high proportion of electrical fires. The samples were diluted in distilled water and water resistivity was measured. Current measurements and tracking reappearance experiments were conducted using distilled water with dust samples. The analysis results were obtained to track the fire risks according to the dust resistivity. The highest value was the dust from cattle sheds followed in order by the dust of pigsties and hen-houses. In experiments measuring the temperature change and RMS current, the lower resistivity of water showed a significant trend of temperature and high amperage. In the tracking reappearance experiment with the lower resistivity water, the tracking speed was fast and the ignition time was shortened. This study investigated why each dust resistivity shows different results.

• Fire Science and Engineering
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• v.17 no.4
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• pp.13-19
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• 2003

In this paper, we studied on the characteristics of RCD(Residual Current Device) case deteriorated by tracking, and compared the tracked samples between in the site of fire($S_1$) and in the reappearance experiment($E_1$). This experiment is applied to IEC Publ. 112 method. Electrical fire by tracking occurred after scintillation and dry-band generated. The insulation resistance between source terminals of RCD case was about 25.7Ω in $E_1$ and the resistance was about 58.6Ω in $S_1$.The exothermic peaks of $E_1$ appeared at $491.0^{\circ}C$ and $603.2^{\circ}C$. The exothermic peak at $603.2^{\circ}C$ was shown by tracking. And the exothermic peak of $S_1$ appeared at $593.1^{\circ}C$. In spectrum of $S_1$ and $E_1$, absorption peak didn't appear at near 1590 cm$^{-1}$ .

• Journal of IKEEE
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• v.11 no.4
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• pp.137-144
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• 2007

Fire Control System(FCS) errors can be classified as hardware errors and software errors, and one of the software errors is from target tracking filter which estimates target's location, velocity, acceleration, and so on. It affects function of ballistic calculation equipment significantly. For gun to form predicted hitting point accurately and enhance hitting rate, we need status information of target's future location. Target tracking filter algorithms consist of Single Singer Model, Fixed Gain filter algorithm, IMM, PBIMM and so on. This paper will design IMM tracking filer, which is going to be! applied to domestic warship. Target tracking filter using CV model, Song model and CRT model for IMM tracking filter is made, and tracking ability is analyzed through Monte-Carlo simulation.

• Journal of Korean Institute of Fire Investigation
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• v.10 no.1
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• pp.87-95
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• 2007

This paper is proposed a novel method to approximate the maximum power for a photovoltaic inverter system and tracking method. It is designed for power systems application and utilities. The proposed Maximum Power Point Tracking (MPPT) control has the advantage to provide a new simple way to approximate the optimal or rated voltage, the optimal or rated current and maximum power rating produced by a solar panel and the photovoltaic inverter. And this straightforward method will be named linear reoriented coordinates method (LRCM) with the advantage that Pmax and $V_{op}$ can be approximated using the same variable as the dynamic model without using complicate approximations or Taylor series. Furthermore tracking method is improved over 50% photovoltaic efficiency. This paper is proposed MPPT using LRMC and tracking method using weather condition of domestic moderate program technique. This paper is proposed the experimental results to verify the effectiveness of the new methods.

• Journal of Ocean Engineering and Technology
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• v.32 no.2
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• pp.138-142
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• 2018

The marine industry is rapidly developing as a result of the increase in various needs in the marine environment. In addition, accidents involving ship fires and explosions and the resulting casualties are increasing. Generally, manpower and safety problems exist in fire fighting. A fire fighter in the form of an autonomous surface robot would be ideal for marine fire safety, because it has no manpower and safety problems. Therefore, an autonomous surface robot with the abilities of fire recognition and tracking, nozzle selection, position and attitude control, and fire fighting was developed and is discussed in this paper. The test and evaluation results of this robot showed the possibility of real-size applications and the need for additional studies.