• Journal of Korea Entertainment Industry Association
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• v.13 no.6
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• pp.329-339
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• 2019

This study intends to identify the effect of the simulation-based adult nursing education on resilience, clinical competence, and role transition of nursing students. Similar experimental study of a single group pretest-posttest design was used to investigate the effects of the program. The study was conducted from March to June, 2017 on senior nursing students at the university in M city who take an 'Integrated nursing practice I' class for the semester. Data were collected through self-report questionnaires and data of 52 participants were analyzed. The data were analyzed by frequencies, paired t-test and pearson's correlation coefficient using SPSS 21.0 program. As a result, the effectiveness of the simulation-based adult nursing education on resilience, clinical competence, and role transition were found. The result of this study showed that the improvement after simulation education was significant in resilience(t=-2.51, p=.016), clinical competence(t=-4.18, p<.001), and role transition(t=-2.89, p=.006). Resilience was found to be positively correlated with clinical competence(r=.464, p<.001) and role transition(r=.473, p<.001). These findings imply the value of simulation education to enhance the resilience, clinical competence, and role transition of nursing students. In the future, more studies should be conducted in the same group with control group to validate the effectiveness of variables.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.12 no.1
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• pp.49-55
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• 2016

This paper analyzed a root cause of abnormality in the temperature and vibration at generator-side bearing of motor generator set (MG Set), which is a power supply system to control element drive mechanism (CEDM) of nuclear power plants (NPPs), and modified the design of roller-type and sealing method to improve the abnormalities. From the inspection of MG Set and analysis of temperature variation during service, it was found that the abnormal temperature transition was basically associated with original design of generator-side bearing, whose roller was axially restrained by inner race, and that the abnormal vibration level was caused by inserting small chips of cage and V-ring, which were generated due to the abnormal temperature transition at roller bearing. Type of bearing and sealing method were modified based on these analyses. The temperature and vibration level measured at roller bearing showed that the modifications clearly improved the operational stability of MG Set.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.819-822
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• 2002

It is necessary for the numerical simulation of 3-dimensional incompressible isotropic decaying turbulence to construct 3-dimensional initial velocity field which resembles the fully developed turbulence. Although the previous velocity field generation method proposed by Rogallo(1981) satisfies continuity equation and 3-dimensional energy spectrum, it has limitation, as indicated in his paper, that it does not produce the higher velocity moments(e. g. velocity derivative skewness) characteristic of real turbulence. In this study, a new velocity field generation method which is able to control velocity derivative skewness of initial velocity field is proposed. Brief descriptions of the new method and a few parameters which is used to control velocity derivative skewness are given. A large eddy simulation(LES) of isotropic decaying turbulence using dynamic subgrid-scale model is carried out to evaluate the performance of the initial velocity field generated by the new method. It was shown that the resolved turbulent kinetic energy decay curve and the resolved enstrophy decay curve from the initial field of new method were more realistic than those from the initial field of Rogallo's method. It was found that the dynamic model coefficient from the former was initially half the stationary value and experienced relatively short transition period, though that from the latter was initially zero and experienced relatively longer transition period.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.1
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• pp.101-108
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• 1997

The initial token value required to the optimal performance of discrete event systems can be decided by Sum of Delay Time and Synchronic Time ratio, which are new synchronic variables in Timed Place Petri Nets. For the system consisting of two Live-and-Bounded circuits(LB-circuits) fused in common Transition-Transition-Path or common Place-Place-Path, we prove that the Synchronic Time Ratio is the initial token ratio between two LB-circuits to optimally perform system functions. These results are generalized and formulated as a theorem. The initial tokens of a specific place can imply shared resources. Using the theorem, we can decide the minimum number of the shared resources to obtain the optimal performance, and minimize the idling time of resources. As an example, an automated assembly system is modeled by Timed Place Petri Net, and the initial tokens to achieve the optimal system performance are identified. All the values are verified by simulation.

• International Journal of Aeronautical and Space Sciences
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• v.2 no.1
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• pp.12-19
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• 2001

Study of turbulent mixing layers has been a popular subject from the point of view of both practical application and phenomenological importance in engineering field. Turbulent mixing layers can be applied in many fields where rapid transition to turbulence is desirable in order to prevent boundary layer separation or to enhance mixing. The ability to control mixing, structure and growth of the shear flow would obviously have a considerable impact on many engineering applications. In addition to practical applications, free shear flows are one of the simplest flows to understand the fundamental mechanism in the transition process to turbulence. After the discovery of large-scale vortical structure in free shear flows many researchers have investigated the physical mechanism of generation and dissipation processes of the vortical structure. This study investigated the role of the large-scale vortical structures in the turbulent mixing layer using LES(Large-Eddy Simulation). The result shows that the pairing interaction of the vortical structure plays an important role in the growth rate of a mixing layer. It is found that the turbulence quantities depend strongly on the velocity ratio. It is also found that the vorticity in the high-velocity-side can extract energy from the mean flow, while the vorticity in the low-velocity-side lose energy by the viscous dissipation. Finally the results suggest the guideline to obtain the desired flow by control of the velocity ratio.

• Journal of Surface Science and Engineering
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• v.39 no.3
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• pp.98-104
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• 2006

Al-doped ZnO (AZO) films were deposited on the plastic substrate by inductively coupled plasma (ICP) assisted DC magnetron sputtering. The AZO films were produced by sputtering a metallic target (Zn/Al) in a mixture of argon and oxygen gases. AZO films with an electrical resistivity of ${\sim}10^3\;{\Omega}cm$ and an optical transmittance of 80% were obtained even at a low deposition temperature. In-situ process control methods were used to obtain stable deposition conditions in the transition region without any hysteresis effect. The target voltage was controlled either at a constant DC power. It was found that the ratio of the zinc to oxygen emission intensity, I (O 777)/I (Zn 481) decreased with increasing the target voltage in the transition region. The $Ar/O_2$ plasma treatment improve the adhesion strength between the polycarbonate substrate and AZO films.

• Electronics and Telecommunications Trends
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• v.38 no.6
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• pp.31-40
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• 2023

Given recent accidents involving autonomous vehicles, driver monitoring technology related to the transition of control in autonomous vehicles is gaining prominence. Driver status monitoring systems recognize the driver's level of alertness and identify possible impairments in the driving ability owing to conditions including drowsiness and distraction. In autonomous vehicles, predictive factors for the transition to manual driving should also be included. During traditional human driving, monitoring the driver's status is relatively straightforward owing to the consistency of crucial cues, such as the driver's location, head orientation, gaze direction, and hand placement. However, monitoring becomes more challenging during autonomous driving because of the absence of direct manual control and the driver's engagement in other activities, which may obscure the accurate assessment of the driver's readiness to intervene. Hence, safety-ensuring technology must be balanced with user experience in autonomous driving. We explore relevant global and domestic regulations, the new car assessment program, and related standards to extract requirements for driver status monitoring. This kind of monitoring can both enhance the autonomous driving performance and contribute to the overall safety of autonomous vehicles on the road.

• The Journal of Korea Robotics Society
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• v.3 no.3
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• pp.226-236
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• 2008

In this paper, control software architecture is designed to enable a heterogeneous multiple humanoid robot demonstration executing tasks cooperating with each other. In the heterogeneous humanoid robot team, one large humanoid robot and two small humanoid robots are included. For the efficient and reliable information sharing between many software components for humanoid control, sensing and planning, CORBA based software framework is applied. The humanoid tasks are given in terms of finite state diagram based human-robot interface, which is interpreted into the XML based languages defining the details of the humanoid mission. A state transition is triggered based on the event which is described in terms of conditions on the sensor measurements such as robot locations and the external vision system. In the demonstration of the heterogeneous humanoid team, the task of multiple humanoid cleaning the table is given to the humanoid robots and successfully executed based on the given state diagram.

• The Transactions of the Korean Institute of Power Electronics
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• v.18 no.3
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• pp.205-210
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• 2013

This paper presents a novel hall sensor fault detection and fault-tolerant control method for a high-speed permanent magnet synchronous motor (PMSM) drive system. A phase locked loop (PLL) type position estimator is used with a conventional interpolation based rotor position estimator to reduce position errors due to misalignment of hall sensors. The expected trigger time of hall sensor's output is used for detecting hall sensor fault condition and the PLL type position estimator is reconfigured for fault-tolerant control at the hall sensor fault condition. The proposed method can minimize current ripples during the transition from sensored control using hall sensors to sensorless control. Experimental results have been proposed to prove the validity of the proposed method.

• Journal of Institute of Control, Robotics and Systems
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• v.17 no.11
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• pp.1125-1131
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• 2011

This paper presents a control theoretic approach to realizing fault tolerance in asynchronous sequential circuits. The considered asynchronous circuit is assumed to work in space environment and is subject to faults caused by total ionizing dose (TID) effects. In our setting, TID effects cause permanent changes in state transition characteristics of the asynchronous circuit. Under a certain condition of reachability redundancy, it is possible to design a corrective controller so that the closed-loop system can maintain the normal behavior despite occurrences of TID faults. As a case study, the proposed control scheme is applied to an asynchronous arbiter implemented in FPGA.