• The KIPS Transactions:PartA
• /
• v.10A no.5
• /
• pp.519-528
• /
• 2003

Container terminals need decisions in the course of daily-24 hour and 365 day - operations, and all these decisions are inter-related. The ultimate goal of Decision Support System is to minimize ship loading/unloading time, resources used to handle the workload, and congestion on the roads inside the terminal. It is also to make the best possible use of the storage space available. Therefore, the necessity of decision support tools are emphasized to enhance the operational efficiency of container shipping terminals more, because of limits and complexity of these decisions. So, in thia paper, we draw evaluation items for Decision Support Systems and suggest optimization strategy of evaluation items which have the greatest influence on Decision Support system, that is, yard stacking allocation, RTGC deployment among blocks, and YT allocation to QCs. We also estimate the efficiency of Decision Support System design by simulation using G2 language, comparing ship loading/unloading time.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.44 no.3
• /
• pp.203-211
• /
• 2016

In contrast with STT missiles, the guidance law design for BTT missiles should be based on 3-dimensional pursuit kinematics, since the pitch and roll channels of BTT missiles are coupled dynamically. More generally than the prior works, the dynamics of pitch and roll channels, as well as 3-dimensional pursuit kinematics are considered in the design of our terminal-phase optimal guidance law for BTT missiles proposed in this paper. Thereby, the proposed optimal guidance law guarantees high capturability with small miss distance without significant performance degradation due to time-lag effect even in case of relatively slow autopilot dynamics. Moreover, the resulting optimal guidance law is expressed explicitly in feedback-form with the coefficients given as the functions of time-to-go. The effectiveness and practicality of our work is demonstrated through various simulation results.

• Journal of Microbiology and Biotechnology
• /
• v.29 no.9
• /
• pp.1375-1382
• /
• 2019

Phenylalanine hydroxylase from Chromobacterium violaceum (CvPAH) is a monomeric enzyme that converts phenylalanine to tyrosine. It shares high amino acid identity and similar structure with a subunit of human phenylalanine hydroxylase that is a tetramer, resulting in the latent application in medications. In this study, semirational design was applied to CvPAH to improve the catalytic ability based on molecular dynamics simulation analyses. Four N-terminal truncated variants and one single point variant were constructed and characterized. The D267P variant showed a 2.1-fold increased thermal stability compared to the wild type, but lower specific activity was noted compared with the wild type. The specific activity of all truncated variants was a greater than 25% increase compared to the wild type, and these variants showed similar or slightly decreased thermostability with the exception of the $N-{\Delta}9$ variant. Notably, the $N-{\Delta}9$ variant exhibited a 1.2-fold increased specific activity, a 1.3-fold increased thermostability and considerably increased catalytic activity under the neutral environment compared with the wild type. These properties of the $N-{\Delta}9$ variant could advance medical and pharmaceutical applications of CvPAH. Our findings indicate that the N-terminus might modulate substrate binding, and are directives for further modification and functional research of PAH and other enzymes.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.19 no.1
• /
• pp.87-93
• /
• 2005

In this paper, we perform the harmonic filter design for Incheon international airport, especially passenger terminal based on the results of measurement and analysis. Also, we show the waveform of machines which produce harmonics as a harmonic source. For harmonic filter design, we propose the APF(Active Power Filter) and ZSF(Zero Sequence Filter) design. Also, we simulate the filter effects using EDSA package. The results show the effectiveness of the method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 1991.06a
• /
• pp.45-48
• /
• 1991

This work aims to introduce the concept of microcomputer aided port design simulation methodology including the analysis of the mathematical models to be implemented and apply it to the Third Stage Busan Part Development Project. In the Busan case study the size of the proposed turning basin of the new terminal together with the operational stra-tegies of berthing and unberthing was examined In addition the safety of ships' entry and exit through the projection new breakwaters was as-certained. From the application of simulation to the Busan project it was found that the proposed dredging area was not sufficiently wide enough for a modelled container ship to perform A type unberthing (in which the ship turns to port as she monoeuvres away from No.1 berth with the ass-istance of tuges) especially in a strong easterly wind., It is therefore recommended that Busan pilots should be advised to use B type unberthing strategy in which the ship goes astern from No.1 berth to the turning area in front of No.2 berth(where the ship turns 180 degrees clockwise) especially when the wind is very strong. It is also recommended that a sea buoy be placed outside the new breakwaters as this was found to im-prove the safety of ship manoeuvres through the breakwaters significant-ly. Another recommendation is that the Korean Hydrodynamic Office carry out a detailed survey of the currents in the water area near the new breakwaters. once they have been constructed. In addition it is to be recommended that a current meter be placed at the recommended sea buoy pardised by erroneous current information

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.7
• /
• pp.89-94
• /
• 2013

This paper presents a method of simulating the protection effects of surge protective devices(SPDs) depending on the protective distance and types of input impedance of load to be protected. In order to analyze the protective performances of voltage-limiting type SPDs associated with the reflection and oscillation phenomena, the terminal voltage across load being protected and the residual voltage of SPDs were simulated by using EMTP model as functions of the protective distance and types of input impedance of loads. As a consequence, SPDs should be installed by taking into account the protective distance and input impedance of loads to achieve reliable protection of electrical and electronic equipment from lightning and switching surges. It is expected that the simulation method proposed in this paper could be practically used in design for installing SPDs in low-voltage distribution systems.

• Transactions on Control, Automation and Systems Engineering
• /
• v.2 no.3
• /
• pp.207-213
• /
• 2000

This paper introduces a high-performance speed control system based on artificial neural networks(ANN) to estimate unknown parameters of a DC servo motor. The goal of this research is to keep the rotor speed of the DC servo motor to follow an arbitrary selected trajectory. In detail, the aim is to obtain accurate trajectory control of the speed, specially when the motor and load parameters are unknown. By using an artificial neural network, we can acquire unknown nonlinear dynamics of the motor and the load. A trained neural network identifier combined with a reference model can be used to achieve the trajectory control. The performance of the identification and the control algorithm are evaluated through the simulation and experiment of nonlinear dynamics of the motor and the load using a typical DC servo motor model.

• International Journal of Control, Automation, and Systems
• /
• v.3 no.spc2
• /
• pp.308-314
• /
• 2005

Transient stabilization with voltage regulation is investigated for a synchronous generator when the mechanical power is perturbed to any unknown value within its physical bounds so that the operating point of the system shifts to an unknown point. An adaptive excitation controller is designed based on the backstepping method with tuning functions. It will be shown that the adaptive control law proposed can achieve the convergence of the system states to the new equilibrium point in correspondence with the real value of the unknown mechanical power and the regulation of the terminal voltage to the required value. Simulation results are given to demonstrate the effectiveness of the proposed controller for the transient stabilization and voltage regulation.

• Proceedings of the KIEE Conference
• /
• 2007.04a
• /
• pp.110-112
• /
• 2007

Output voltage waves of a DC/AC inverter system are likely to be distorted if variable loads e.g. motors or rectifiers exist in the output terminal. This paper designs a disturbance observer-based PI controller for a single-phase inverter system that is robust against load changes. In this paper, we regard the output voltage changes due to various loads as disturbances of the control system, Then we design a disturbance observer for estimation of the disturbances caused by the load current and any other error sources (such as parameter uncertainties and model mismatches etc.). In order to test the performance of the proposed control law, simulation studies are carried out for a single-phase inverter system using SimPowerSystems of Matlab Simulink. Compared to a simple PI control, the disturbance observer-based controller shows enhanced performance in transient responses for step load changes.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.8 no.5
• /
• pp.442-449
• /
• 2003

This paper discusses how to generate the reference compensation voltages in Dynamic Voltage Restorers (DVR) by use of PQR instantaneous power theory. Sensed three-phase terminal voltages are transformed to PQR coordinates without time delay. Since the reference voltage in PQR coordinates is a single dc value, the voltage controller for DVRs is simple and easy to design. Proposed control method can be implemented by feedforward controllers or by feedback controllers. This paper verified the theory by a feedforward controller of a DVR with simulation and experiment.