• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2635-2642
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• 2012

MOST(Media Oriented Systems Transport) is a network protocol for vehicle multimedia, where it guarantees large bandwidth and reliability. However, previous MOST device utilized I2C or I2S communication method to data manage or transfer, Bandwidth of MOST have increased and additional equipments are added to one device, requiring a larger form of bandwidth communication method. Therefore, this research suggests of the methods in improving the efficiency of asynchronous data transfer, and suggest an algorithm, which will improve the reliability.

• Journal of the Institute of Electronics and Information Engineers
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• v.51 no.7
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• pp.96-102
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• 2014

In this paper, we proposed new dual-rail data encoding that mixed 4-phase handshaking protocol and 2-phase handshaking protocol for asynchronous system design to reduce signal activities and power consumption. The dual-rail data encoding 4-phase handshaking protocol should leat to much signal activities and power consumption by return to space state. Ideally, the dual-rail data encoding 2-phase handshaking protocol should lead to faster circuits and lower power consumption than the dual-rail 4-phase handshaking protocol, but can not designed using standard library. We use a benchmark circuit that contains a multiplier block, an adder block, and latches to evaluate the proposed dual-rail data encoding. The benchmark circuit using the proposed dual-rail data encoding shows an over 35% reduction in power consumption with 4-phase dual-rail data encoding.

• The Journal of Korean Academic Society of Nursing Education
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• v.27 no.4
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• pp.381-391
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• 2021

Purpose: This study aimed to identify the influence of learning presence and self-directed learning ability on nursing students' learning satisfaction according to the online learning method. Methods: The participants of this study were 167 nursing students attending three universities in different cities. The data were collected from July 16 to July 23, 2021, via an online self-reported questionnaire. Using SPSS WIN 27.0, data were analyzed by descriptive statistics, Pearson's correlation coefficient and a multiple regression analysis. Results: The most effective online learning method experienced by nursing students was asynchronous online learning according to 58.2% of the respondents, while 30.3% of the respondents answered synchronous online learning. The main merit of asynchronous online learning was that it was possible to listen repeatedly (61.7%) to lectures, and the top advantage of synchronous online learning was that the location of the class was free (53.3%). In asynchronous online learning, the factors that significantly affected nursing students' learning satisfaction were cognitive presence (𝛽=.60, p<.001) and emotional presence (𝛽=.25, p<.001). These variables accounted for 56% of their learning satisfaction (F=54.12, p<.001). Similarly, cognitive presence (𝛽=.64, p<.001) and emotional presence (𝛽=.21, p=.001) in synchronous online learning, were the factors cited for significantly affecting learning satisfaction. The explanatory power was 62% (F=69.19, p<.001). Conclusions: In conclusion, it was found that cognitive and social presence from the learning presence factors in both asynchronous and synchronous online learning influence and enhance nursing students' learning satisfaction. Therefore, these results provide important data for future online class design in nursing education.

• International Journal of Fluid Machinery and Systems
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• v.10 no.2
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• pp.164-175
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• 2017

Francis turbines are often operated over a wide load range due to high flexibility in electricity demand and penetration of other renewable energies. This has raised significant concerns about the existing designing criteria. Hydraulic turbines are not designed to withstand large dynamic pressure loadings on the stationary and rotating parts during such conditions. Previous investigations on transient operating conditions of turbine were mainly focused on the pressure fluctuations due to the rotor-stator interaction. This study characterizes the synchronous and asynchronous pressure and velocity fluctuations due to rotor-stator interaction and rotating vortex rope during load variation, i.e. best efficiency point to part load and vice versa. The measurements were performed on the Francis-99 test case. The repeatability of the measurements was estimated by providing similar movement to guide vanes twenty times for both load rejection and load acceptance operations. Synchronized two dimensional particle image velocimetry and pressure measurements were performed to investigate the dominant frequencies of fluctuations, vortex rope formation, and modes (rotating and plunging) of the rotating vortex rope. The time of appearance and disappearance of rotating and plunging modes of vortex rope was investigated simultaneously in the pressure and velocity data. The asynchronous mode was observed to dominate over the synchronous mode in both velocity and pressure measurements.

• The Journal of Engineering Research
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• v.1 no.1
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• pp.41-48
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• 1997

In this paper, we wxtend DMSA system to support multimedia traffic more efficiently by incorporating a priority scheme. we divide network stations into two types: asynchronous and isosynchronous stations, and we give a priority to the isosynchronous stations over the asynchronous stations by imposing a time-out constraint on the asynchronous stations . we derive the maximum number of isosynchronous stations the proposed priority scheme can support simultaneously and the maximum bandwidth that can be utilized by asynchronous stations in the presence of isosynchronous traffic. We also provide simulation results for the mixed voice and data traffic, and compare them to the analytic results.

• Research in Community and Public Health Nursing
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• v.33 no.3
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• pp.312-320
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• 2022

Purpose: This study was performed to explore the effect of the delivery format on teaching presence, learning presence, and learning outcomes in distance learning of nursing students. Methods: A descriptive survey was conducted to understand teaching presence, learning presence, and learning outcomes depending on the delivery format of distance learning. Quota sampling methodology was used to recruit 295 nursing students from all over the country, and data collection was done from July 27 to September 10, 2020. The first delivery format for distance learning was synchronous learning in which communication between the instructor and students occurred simultaneously. The second delivery format was asynchronous learning in which prerecorded videos were provided and communication did not occur simultaneously. Results: In synchronous learning, teaching presence (especially direct facilitation) and learning presence (especially emotional expression) had a statistical significance that was higher than in asynchronous learning. However, in learning outcomes, there was no statistically significant difference. There were significant positive correlations between teaching presence, learning presence, and learning outcomes, and there were significant positive correlations. Conclusion: It can be suggested that learning outcomes can be improved if presence is improved in the distance learning environment based on the results of this study. It is necessary to add contact with nursing students and instructors to improve teaching presence in the asynchronous learning, and it is necessary to help students express their emotions to improve learning presence.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.145-148
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• 2000

A 16bit asynchronous multiplier has been designed using micropipelind structure with 2 phase and data bundling. And 4-radix modified Booth algorithm, CPlatch(Cature-Pass latch) and modified 4-2 counters have adopted in this design. It is implemented in 0.65$\mu\textrm{m}$ double-poly/double-metal CMOS technology by using 12,074 transistors with core size of 1.4${\times}$1.8$\textrm{mm}^2$. And our design results in a computation rate 55MHz a supply voltage of 3.3V.

• Proceedings of the KIEE Conference
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• 2005.07d
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• pp.2661-2663
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• 2005

To construct the stable back-up system between mini-hubs, we propose the plan of site diversity of asynchronous mini-hub by monitoring outlink carriers and error data. In this paper, we made hardware and software to control mini-hub system for site diversity back-up by switching SDBS equipment through communication between master mini-hub and slave mini-hub.

• Journal of Mechanical Science and Technology
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• v.14 no.6
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• pp.590-596
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• 2000

Cause of excessive vibration with twice the rotational speed of a two-pole generator rotor for the fossil power plants was investigated. The two-pole generator rotor, treated as a typically asymmetric rotor in vibration analysis, produces asynchronous vibration with twice the rotational speed, sub-harmonic critical speeds, and potentially unstable operating zones due to its own inertia and/or stiffness asymmetry. This paper introduces a practical balancing procedure, and presents the results of the investigation on sources of the excessive vibration based on the experimental vibration data of the asymmetric two-pole rotor in balancing.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.883-886
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• 1998

We introduce a high level synthesis methodlogoy for automatic synthesis of asynchronous circuits form a language based on CSP. The input language is a high level concurrent algorithmic specification that can model complex concurrent control flow, logical and arithmetic computation and communications between them. This specification is translated into petri net which has actions. These actions are refined to synthesize the controllers and to allocate the data resources. We use the automatic synthesis through signal transition graphs (STGs) that allows to take advantage of logic synthsis methods to optimize the circuit.