• Journal of the Korea Institute of Building Construction
• /
• v.8 no.5
• /
• pp.109-117
• /
• 2008

Recently, there has been constituted the government regulations and the normative methods to control the safety management activities in construction fields, but almost of these regulations are ineffective, because of some characteristics safety management have. The needs of the times make government regulations and the normative methods change to autonomic management methods. In this context, it is significant certainly to improve the standard of safety management that is used as a tool to protect the workers from the accidents or industrial disasters in the construction field. In this research, it will be showed that the outside regulations and safety management systems of the head office have their limits to reflect the safety managements of field participants. Then, it will be presented the improved model of self-control safety management activities which is essential for success safety management.

• Proceedings of the Korea Institute of Convergence Signal Processing
• /
• 2005.11a
• /
• pp.167-170
• /
• 2005

Recently, filtering methods for attenuating noise while preserving image details are in progress actively. And SM(standard median) filter showed a great performance for noise removal in impulse noise environment but, it caused edge cancellation error. So, variable methods that modified SM(standard median) filter have been proposed, and CWM(center weighted median) filter is representative. Also, there are several methods to improve the efficiency based on min/max operation in term of preserving detail and filtering speed. In this paper, we managed a pixel corrupted by impulsive noise using min/max value of the surrounding band enclosing a pixel, and compared the efficiency with exiting methods in the simulation.

• International Journal of Fuzzy Logic and Intelligent Systems
• /
• v.11 no.4
• /
• pp.267-274
• /
• 2011

Recently, actor-critic methods have drawn significant interests in the area of reinforcement learning, and several algorithms have been studied along the line of the actor-critic strategy. In this paper, we consider a new type of actor-critic algorithms employing the kernel methods, which have recently shown to be very effective tools in the various fields of machine learning, and have performed investigations on combining the actor-critic strategy together with kernel methods. More specifically, this paper studies actor-critic algorithms utilizing the kernel-based least-squares estimation and policy gradient, and in its critic's part, the study uses a sliding-window-based kernel least-squares method, which leads to a fast and efficient value-function-estimation in a nonparametric setting. The applicability of the considered algorithms is illustrated via a robot locomotion problem and a tunnel ventilation control problem.

• Journal of Korean Institute of Industrial Engineers
• /
• v.34 no.2
• /
• pp.122-139
• /
• 2008

With the proliferation of in-process measurement technology, autocorrelated data are increasingly common in industrial SPC applications. A number of high performance control charting techniques that take into account the specific characteristics of the autocorrelation through time series modeling have been proposed over the past decade. We present a survey of such methods and analyze and compare their performances for a range of typical autocorrelated process models. One practical concern with these methods is that their performances are often strongly affected by errors in the time series models used to represent the autocorrelation. We also provide some analytical results comparing the robustness of the various methods with respect to time series modeling errors.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.9
• /
• pp.1680-1685
• /
• 2010

In this note, a proof of Utkin's theorem is presented for a MI(Multi Input) uncertain linear case. The invariance theorem with respect to the two transformation methods so called the two diagonalization methods are proved clearly and comparatively for MI uncertain linear systems. With respect to the sliding surface transformation and the control input transformation, the equation of the sliding mode i.e., the sliding surface is invariant. Both control inputs have the same gains. By means of the two transformation methods the same results can be obtained. Through an illustrative example and simulation study, the usefulness of the main results is verified.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2013.05a
• /
• pp.886-888
• /
• 2013

An edge includes information of objects such as magnitude, orientation, and location. Conventional edge detection methods to detect those edge are methods using Sobel, Prewitt, Roberts, Laplacian operator. Existing methods use fixed weighted mask to detect edges, and their edge detection characteristics are insufficient. Therefore, to remedy weakness of conventional methods, in this paper, an edge detection algorithm using weight with standard deviation and thresholds is proposed.

• 보존과학연구
• /
• s.13
• /
• pp.69-80
• /
• 1992

A great numbers of cultural properties destroyed though attack by insect pests and microorganisms. Biodeterioration damage is particularly serious in this country because many cultural propertiese are made of organic materials. Recently, there are various countermeasures of biodeterioration or alternative methods are reported, such as Gamma Radiation, Micro-wave Irridation, Freezing, Inert Atmosphere (Oxygen-less atmosphere), and Environmental Control. However its practical application are limited and some difficulties for treatment of large objects. Fumigation is one of the most useful and effective methods of control biodeterioration because it gives less damage of cultural properties but rapidly eradicate infesting organisms at one action. This paper evaluated selected fumigants and fumigation methods with emphasis on the following paragraph:1) Effectiveness of selected fumigants on insects and microbes involved inbiodeterioration.2) Physical and chemical characters of selected fumigants.3) Less toxic new alternative fumigant and its mixtures.4) Inert atmosphere (Oxygen-less atmosphere)5) Methods of fumigation : Sealed fumigation, Covered fumigation and Vacuum fumigation (Reduced-pressure fumigation)

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.27 no.4
• /
• pp.179-186
• /
• 2015

In this study, the actual energy consumption of the secondary side District Heating System (DHS) with different hot water supply temperature control methods is compared. The two methods are Outdoor Temperature Reset Control and Outdoor Temperature Predictive Control. While Outdoor Temperature Reset Control has been widely used for energy savings of the secondary side system, the results show that the Outdoor Temperature Predictive Control method saves more energy. In general, the Outdoor Temperature Predictive Control method lowers the supply temperature of hot water, and it reduces standby losses and increases the overall heat transfer value of heated spaces due to more flow into the space. During actual energy consumption monitoring, the Outdoor Temperature predictive Control method saves about 6.6% of energy when compared to the Outdoor Temperature Reset Control method. Also, it is found that at partial load condition, such as during daytime, the fluctuation of hot water supply temperature with Outdoor Temperature Reset Control is more severe than that with Outdoor Temperature Predictive Control. Thus, it proves that Outdoor Temperature Predictive Control is more stable even at partial load conditions.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.66 no.9
• /
• pp.1325-1333
• /
• 2017

The sensorless control of blushless DC motor(BLDCM) is based on the $120^{\circ}$ control in which the back electromotive force(Back EMF) for estimating the position of the rotor can be detected. However, the $120^{\circ}$ control has a disadvantage that the torque constant is small as compared with $180^{\circ}$ control which can not detect the back EMF. The $150^{\circ}$ control which complements these problems makes it possible to detect the back EMF and improve the torque constant by 12.5% compared to the $120^{\circ}$ control. Therefore, this paper compares the output characteristics of BLDCM through finite element method analysis (FEA) by the conventional and proposed control methods of BLDCM for water circulation system and proposes design for downsizing and weight reduction of BLDCM according to secured torque constant. The validity of the proposed control and design proposal is proved through simulation and experimental results by comparing the output characteristics of $120^{\circ}$ control and $150^{\circ}$ control.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.34 no.12
• /
• pp.1885-1891
• /
• 2010

Torque control of wind turbines is important when the wind speed is below the rated speed. The main objective of torque control is to extract the maximum power from the potential aerodynamic power of the wind. Torque control methods for wind turbines are classified as torque-mode control and speed-mode control. In torque-mode control, which is well known and traditionally used in many wind turbines, the torque demand of the generator is proportional to the square of the generator speed. In speed-mode control, a PI controller is used to generate the appropriate torque demand of the generator. In this study, the two torque control methods mentioned above are applied to a 2.75-MW wind turbine; simulation results for real turbulence wind speeds are presented, and the response properties are compared.