• Journal of the Korea Institute of Building Construction
• /
• v.11 no.1
• /
• pp.73-81
• /
• 2011

The ultimate goal of construction is to complete the given work in the most economical and safest way within the required construction period while meeting the quality standards specified in the design drawing. There are a few characteristics of finish work. First, executed in subdivided processes, finish work involves a very diverse and complex structure. Second, there are no criteria for each segmented process with regard to the appropriate time of input. Third, it is not very necessary to set priorities for lead and lag works. This study intends to provide information on the completion of a project in accordance with the required duration by setting priorities in the delay of each detailed process of finish work to minimize delay in finish work. In this study, finish work is divided into wet work and other types of finish work, and the importance of each process is classified based on the given details of each process. In addition, the study employs a survey to analyze delay factors of a designer, a constructor, and a supplier. Using the survey results, the study sets priorities in delay of final work to provide information on the completion of an apartment project within the planned construction period.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.35 no.11
• /
• pp.503-510
• /
• 1986

A new algorithm based on the concept of prediction error minimization is suggested to estimate the time varying delay in discrete processes. In spite of the existence of the stochastic noise, this algorithm can estimate time varying delay accurately. Computation time of this algorithm is far less than that of the previous extended parameter methods. With the use of this algorithm, generalized minimum variance control shows good control behavior in simulations.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.12
• /
• pp.1173-1177
• /
• 2006

Using an inner P controller, a tuning rule useful for processes with wide ratios of time delay over time constant is proposed. Internal model control method and pole assignment method are utilized. It can be used for processes with wide range of the ratio of time delay to time constant without incovenience to choose different tuning rules.

• Journal of Advanced Marine Engineering and Technology
• /
• v.32 no.2
• /
• pp.336-342
• /
• 2008

Simple tuning methods of PI, PD and PID controller are proposed for an integrating process with time delay. This is based on matching the coefficients of corresponding powers of s in the numerator and that in the denominator of the closed-loop transfer function. For set-point tracking problem, the derived controller is found to be a PD controller which is shown by Lee's tuning rule based on minimizing the performance indexes (ISE, IAE, ITAE) using a real-coded genetic algorithm. A method can be also proposed PI, PID controllers according to tuning parameter lambda $({\lambda})$ similar to IMC method. Simulation example is given to illustrate the set-point tracking and disturbance rejection performance of the proposed method.

• Journal of the Korean Society of Safety
• /
• v.21 no.4 s.76
• /
• pp.66-72
• /
• 2006

An accurate knowledge of the AITs(autoignition temperatures) is important in developing appropriate prevention and control measures in industrial fire protection. The measurement of AITs are dependent upon many factors, namely initial temperature, pressure, vessel size, fuel/air stoichiometry, catalyst, concentration of vapor, ignition delay time. The values of the AITs used process safety are normally the lowest reported, to provide the greatest margin of sefety. This study measured the AITs of o-xylene+n-pentanol system from ignition delay time by using ASTM E659-78 apparatus. The experimental AITs of o-xylene and n-pentanol were $480^{\circ}C\;and\;285^{\circ}C$, respectively. The experiment AITs of o-xylene+n-pentanol system were a good agreement with the calculated AITs by the proposed equations with a few A.A.D.(average absolute deviation).

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.125-126
• /
• 2011

Construction projects are being more complicated in proportion to the economic development. Process management is a critical issue in the construction that decides success of a project. Especially, a TACT method which divides and manages resources to repeat each activity is more important. Although becoming an issue dealing with the delay at winter season, it is not property developed. This paper suggests 'activity priority method' and 'TACT unit method' through case study. We validate necessity and efficiency of the TACT method through simulations and a survey. We expect cost reduction by decreasing unnecessary spending.

• Journal of Institute of Control, Robotics and Systems
• /
• v.5 no.7
• /
• pp.800-807
• /
• 1999

A Periodic disturbance canceller is proposed to compensate for the periodic disturbance due to cutting process in a CNC machining center. The periodic disturbance canceller estimates the Periodic disturbance without phase delay. This is achieved by using linear phase low-pass filter and frequency response reciprocal filter of plant at the frequency of the periodic disturbance. This method is implemented in the position control system of the CNC machining center with general disturbance compensators in order to compensate for both the frictional force and the periodic disturbance. The experimental results are described to show its effectiveness.

• Journal of Advanced Marine Engineering and Technology
• /
• v.26 no.1
• /
• pp.132-137
• /
• 2002

Recently, impinging spray is used for atomization of diesel engine, but it bring on adhesion of fuel. Therefore, we studied about droplet behavior on high temperature plate changing the size of droplet, surface temperatures, and surface roughness of plate. In this study, We studied to confirm experimentally about mechanism of evaporation and ignition process of single fuel droplet. We observed evaporation time, evaporation appearance and ignition delay time by the photopraphs of 8mm video camera. Experimental results are summarized as follows: 1. The boiling point of fuel affect a evaporation and ignition process. 2. The surface roughness affect a evaporation time. 3. The ignition delay time relate to evaporation characteristic.

• Journal of Korea Multimedia Society
• /
• v.20 no.11
• /
• pp.1803-1810
• /
• 2017

A large amount of processing time is required if the process of detecting the touch position on the touch screen and displaying it on the display panel is performed only by software. In this paper, we propose a method to output information touched on the screen using H/W method in order to improve the response speed delay. In the FPGA module designed for the HDMI signal output to the display module, the touch information is input to the serial data signal including touch coordinate information, point size, and color information. Then the module render the image using HDMI signal input to the module and the touch information. This method has a pipeline structure so it has effect of reducing the delay time that occurs in outputting the touch information compared with the conventional software processing method.

• 제어로봇시스템학회:학술대회논문집
• /
• 2000.10a
• /
• pp.109-109
• /
• 2000

In process industries, more than 90% of the control loops have PID controller. Futhermore, the most control systems are using classical PID controllers for their process control. Various auto-tuning methods of PID gains using relay-feedback are presented recently. In order to get the desired control performance, the correct tuning of PID controller is very important. This paper suggests how to tune of digital PID gains using information for both the Nyquist critical point by conventional method and another point by the relay feedback and hidden time-delay term. Simulation results show that the proposed controller has better performance than the conventional method.