• Journal of the Korean Society of Safety
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• v.15 no.1
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• pp.167-175
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• 2000

Work performance and human error are complicated phenomena so that it is very difficult to grasp the true nature of them. However, Event Related Potential (ERP) may give a clue to them because human brain reflects diverse psychophysiological process. In the present study, the possibility of ERP application to the ergonomic area was evaluated in view of grasping error symptoms. For that purpose, the subjects were asked to count specific characters in a random character matrix on a computer monitor, and their ERP was compared with their performance data. Based upon the results, the amplitude of P300 was not so high as that in the case of the Odd Ball tasks, correct response corresponded with stable ERP with high P300 amplitude whereas wrong response did with unstable, fluctuating ERP with low P300 amplitude. Those results coincided with the work performance, and it was concluded that 3-wave fluorescent with illumination level of 800 lux would be recommendable for the counting task in concern. Conclusively, ERP including P300 might supply an objective clue to the problem of human errors in cognitive process.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.5-8
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• 2004

Domestic city gas is supplying in an about 10 million household on present 34 city gas companies because is begun to supply regularly after two 1980 years middle. But, result that focus on city gas supply spread and stable supply for supply area and neglects about safety problem, hundreds casualties such as Ahyun explosion accident and Deagu city gas explosion accident were reached in situation that occurred large size calamity occurs it is dizzliness. In the case of advanced nation, can see that accomplish system and progress that in technology after experience major accident. Therefore, grasp problem investigating safety actual conditions for city gas institution and study about solvable plan is required this. Also, must guide reform and level elevation of a domestic company safety technology through induction and development of safety technology that is suitable in supply, domestic real condition etc. Must help in power positivity that is full text executing high-quality safety education about step High firing mechanism safety technology than present safety education.

• Atmosphere
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• v.22 no.2
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• pp.199-208
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• 2012

This study was conducted in order to analyze weather characteristics during the reign of King Sejo in the Chosun Dynasty based on The Annals of the Chosun Dynasty. For this purpose, first of all, we need to determine whether The Annals of the Chosun Dynasty is a reliable material for research on weather characteristics. Thus, we compared weather phenomena during the reign of King Sejo with those in China and Japan in the same period. From the results, it was found that The Annals of the Chosun Dynasty is a useful material at least to grasp macroscopic trends in weather phenomena. Based on this assumption, we analyzed weather characteristics during the reign of King Sejo using data from The Annals of the Chosun Dynasty. During the days of King Sejo, the climate was not changed violently and there were not many disasters caused by abnormal climate such as bad harvests. This suggests that the climate was relatively stable during the period of King Sejo. As a consequence of stable weather, famine decreased markedly. However, this was not only because of stable climate but also because of the government's active efforts to reduce disasters. As droughts and floods were not frequent, social costs for recovery from disasters also decreased considerably and the saved money could be invested in the construction of social safety nets for the prevention of disasters. One of factors supporting the enthronement of King Sejo was a series of heavily damaging bad harvests during the reign of Kings Munjong and Danjong. The prevention of bad harvests was a historical mission given to the regime of King Sejo. During his reign, King Sejo promoted various policies in order to stop bad harvests. Such efforts included the government's active construction of embankments, introduction of seeds suitable for reclaimed lands, and inspiration of the consciousness of forceful farming enduring natural disasters such as floods. As a result, abnormal weathers such as floods and droughts did not lead directly to bad harvests.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.265-271
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• 1992

It is the purpose of this paper to present a dialogical designing method for control system using a rough grasp of the unknown process property. We deal with a single-input single-output feedback control system with a fuzzy controller. The process property is roughly estimated by the step response, and the fuzzy controller is interactively modified according to the operator's requests. The modifying rules mainly derived from computer simulation are useful for almost every process, such as an unstable process and a non-minimum phase process. The fuzzy controller is tuned by taking notice of four characteristics of the step response: (1) rising time, (2) overshoot, (3) amplitude and (4) period of vibration. The tuning position of the controller is fourfold: (1) antecedent gain factor GE or GCE, (2) consequent gain factor GDU, (3) arrangement of the antecedent fuzzy labels and (4) arrangement of the control rules. The rules give an instance to the respective items of the controller in an effective order. The modified fuzzy PI controller realizes a good response of a stable process. However, because the GDU tuning becomes difficult for the unstable process, it is necessary to evaluate the stability of the process from the initial step response. The fuzzy PI controller is applied to the process whose initial step response converges with GDU tuning. The fuzzy PI controller with modified sampling time is applied to the process whose step response converges under the repeated application of the GDU tuning. The fuzzy PD controller is applied to the process whose step response never converges by the GDU tuning.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.7
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• pp.289-302
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• 2019

Structural change of time series means that the distribution of observations is relatively stable in the period of constituting the entire time series data, but shows a sudden change of the distribution characteristic at a specific time point. Within a non-stationary long-term time series, it is important to determine in a timely manner whether the change in short-term trends is transient or structurally changed. This is because it is necessary to always detect the change of the time series trend and to take appropriate measures to cope with the change. In this paper, we propose a method for decision makers to easily grasp the structural changes of time series by visualizing the test results based on the unit root test. Particularly, it is possible to grasp the short-term structural changes even in the long-term time series through the method of dividing the time series and testing it.

• KEPCO Journal on Electric Power and Energy
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• v.2 no.3
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• pp.425-431
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• 2016

Supply Capability of the generator, if the maximum demand occurs, refers to the maximum power that can be stably supplied and it is possible to maintain stable power supply to be greater than actual load. However, unexpected power demand and reduction in supply Capability due to stop of unexpected generator in operation can temporarily make a big chaos in power system. In fact, due to a lack of power supply Capability in the country, enforced emergency load adjustment to the September 15, 2011, the circulation power outage has occurred in several cities. As the result, interrupted operation of the elevator and stopped hospital medical equipment led to a great deal of trouble to people's lives, causing a social problem. At that time, it was found that a failed frequency control because of smaller actual supply Capability than that of predicted. The difference was about 1,170 MW with Gas turbine power plant. By accurately calculating the generator supply capability, we can not only grasp the power reserve rate, but also correspond to the time of power supply instability.

• Journal of the Korean Society of Combustion
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• v.13 no.2
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• pp.33-41
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• 2008

The high permeability of the gas in the molten iron of the dripping zone of the blast furnace is a major factor in achieving the stable operation of a furnace with high productivity. Basic studies of the liquid flow behavior in a packed bed are necessary to grasp the effect of various operational changes on conditions in the dropping zone. Molten iron and slag together playa critical role in the lower zone, transporting mass and energy, while impairing and redistributing the gas flow. In turn, molten iron and slag undergo physical and chemical changes, and are redistributed radially as they descend to the hearth. In this research, mathematical formulations are derived for the gas and the liquid. The solid phase is fixed with constant porosity. The information for the molten iron and slag includes the hold-up, velocity, pressure, and information related to the areas of interaction between the gas and the liquid, and the solid and the liquid. Predictable results include the velocity, pressure and temperature distribution. Additional parameters include the packed particle size and the air blast rate.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.651-656
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• 2010

This paper proposes a new dynamic PCA algorithm to recognize types of electric poles, which is necessary for a mobile robot moving along the neutral line for inspecting high-voltage facilities. Since the mobile robot needs to pass over the electric poles and grasp the neutral wire again for the next region inspection, the detection of the electric pole type is a critical factor for the successful passing-over the electric pole. The CCD camera installed on the mobile robot captures the image of the electric pole while it is approaching to the electric pole. Applying the dynamic PCA algorithm to the CCD image, the electric pole type has been classified to provide the stable grasping operation for the mobile robot. The new dynamic PCA algorithm replaces the reference image in real time to improve the robustness of the PCA algorithm, adjusts the brightness to get the clear images, and applies the Laplacian edge detection algorithm to increase the recognition rate of electric pole type. Through the real experiments, the effectiveness of this proposed dynamic PCA algorithm method using Laplacian edge detecting method has been demonstrated, which improves the recognition rate about 20% comparing to the conventional PCA algorithm.

• The KIPS Transactions:PartD
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• v.12D no.7 s.103
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• pp.1031-1038
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• 2005

In this paper, the maximum traffic quantity and actual traffic quantify of the data which are needed to grasp the statement of a system will be measured more accurately. A concrete quality measurement will be conducted by analysing a change of traffic quantity according to a protocol change and traffic under an overload condition when there is an accident. As a result can make an opportunity to maximize safety of power SCADA. Furthermore, future traffic quantity can be prospected by knowing current traffic quantity and grasping the rate of increase by the analysis and the information can be used as data to secure the band width in advance. It can make stable operation of power SCADA by arranging the limited network resources efficiently by information analysis of a network and expects more confidence.

• Journal of Korean Association for Spatial Structures
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• v.3 no.1 s.7
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• pp.87-97
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• 2003

The structural system that discreterized from continuous shells is frequently used to make a large space structures. As well these structures show the unstable phenomena when a load level over the limit load, and snap-through and bifurcation are most well known of it. For the collapse mechanism, rise-span ratio, element stiffness and load mode are main factor, which it give an effect to unstable behavior. In our real situation, most structures have semi-rigid joint that has middle characteristic between pin and rigid joint. So the knowledge of semi-rigid joint is very important problem of stable large space structure. And the instability phenemena of framed space structures show a strong non-linearity and very sensitive behavior according to the joint rigidity For this reason In this study, we are investigating to unstable problem of framed structure with semi-rigidity and to grasp the nonlinear instability behavior that make the fundamental collapse mechanism of the large space frame structures with semi-rigid joint, by proposed the numerical analysis method. Using the incremental stiffness matrix in chapter 2, we study instability of space structures.