• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.5C
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• pp.527-539
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• 2009

In this paper, we propose an asynchonous ICI (Inter-Cell Interference) mitigation techniques for 3GPP LTE MIMO-OFDMA down-link receiver. An increasing in symbol timing misalignments may occur relative to sychronous network as the result of BS (Base Station) timing differences. Such symbol synchronization errors that exceed the guard interval or the cyclic prefix duration may result in MAI (Multiple Access Interference) for other carriers. In particular, at the cell boundary, this MAI becomes a critical factor, leading to degraded channel throughput and severe asynchronous ICI. Hence, many researchers have investigated the interference mitigation method in the presence of asynchronous ICI and it appears that the knowledge of the SCM (Spatial Covariance Matrix) of the asynchronous ICI plus background noise is an important issue. Generally, it is assumed that the SCM estimated by using training symbols. However, it is difficult to measure the interference statistics for a long time and training symbol is also not appropriate for MIMO-OFDMA system such as LTE. Therefore, a noise reduction method is required to improve the estimation accuracy. Although the conventional time-domain low-pass type weighting method can be effective for noise reduction, it causes significant estimation error due to the spectral leakage in practical OFDM system. Therefore, we propose a time-domain sinc type weighing method which can not only reduce the noise effectively minimizing estimation error caused by the spectral leakage but also implement frequency-domain moving average filter easily. By using computer simulation, we show that the proposed method can provide up to 3dB SIR gain compared with the conventional method.

• Journal of the Semiconductor & Display Technology
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• v.19 no.3
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• pp.118-123
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• 2020

In this paper, the design method of asynchronous nonvolatile memory module that can efficiently process and store large amounts of data without loss when the power turned off is proposed and implemented. PSRAM, which takes advantage of DRAM and SRAM, was used for data processing, and NAND flash memory was used for data storage and backup. The problem of a lot of signal interference due to the characteristics of memory devices was solved through PCB design using high-density integration technology. In addition, a boost circuit using the super capacitor of 0.47F was designed to supply sufficient power to the system during the time to back up data when the power is off. As a result, an asynchronous nonvolatile memory module was designed and implemented that guarantees reliability and stability and can semi-permanently store data for about 10 years. The proposed method solved the problem of frequent data loss in industrial sites and presented the possibility of commercialization by providing convenience to users and managers.

• Bulletin of the Korean Chemical Society
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• v.34 no.7
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• pp.1961-1966
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• 2013

Theoretical investigations have been performed for the ground state ($S_0$) and the first excited state ($S_1$) of the hydrogen bonded green fluorescent protein (GFP) model. The potential energy surface (PESs) of $S_0$ was obtained by B3LYP method and that of $S_1$ was obtained by CIS method. Based on the relative stabilities of species and the energy barriers for the proton transfer, it was found that proton transfer could take place both under the ground state and the first excited state. As determined by the proton motions along the reaction coordinate, both the ground state proton transfer (GSPT) and the excited state proton transfer (ESPT) are considered as a concerted and asynchronous process.

• Proceedings of the IEEK Conference
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• 2000.06b
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• pp.137-140
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• 2000

In this paper, we have proposed an efficient test generation method for asynchronous circuits. The test generation is based on specification level, especially on Signal Transition Graph(STG)〔1〕 which is a kind of specification method for asynchronous circuits. To conduct a high-level test generation, we have defined a high-level fault model, called single State Transition Fault(STF) model on STG and proposed a test generation algorithm for STF model. The effectiveness of the proposed fault model and its test generation algorithm is shown by experimental results on a set of benchmarks given in the form of STG. Experimental results show that the generated test for the proposed fault model achieves high fault coverage over single input stuck-at fault model with low cost. We have also proposed extended STF model with additional gate-level information to achieve higher fault coverage in cost of longer execution time.

• Journal of the Korean Institute of Telematics and Electronics
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• v.11 no.2
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• pp.22-26
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• 1974

To synthesize transition-sensitive asynchronous sequential circuits, D-type transition-sensitive flip-flop is used.4 new concept, a pair of input state is introduced and used to reduce the number of internal states. We proposed an algorithm to synthesize multiple-input change asynchronous sequential circuits directly from a primitive state table an6 demonstrated the method is better than the one which is due to Bredeson and Hulina and Others.

• Journal of the Korea Institute of Military Science and Technology
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• v.10 no.2
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• pp.61-68
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• 2007

In a naval combat system, the information processing node is a key functional equipment and performs major combat management functions including control sensor and weapon systems. Therefore, a failure of one of the node causes fatal impacts on overall combat system capability. There were many methodologies to enhance system availability by reducing the impact of system failure like a fault tolerant method. This paper proposes a fault tolerant mechanism for information processing node using a replication algorithm with hardware duplication. The mechanism is designed as a generic algorithm and does not require any special hardware. Therefore all applications in combat system can use this functionality. The asynchronous characteristic of this mechanism provides the capability to adapt this algorithm to the module which has low performance hardware.

• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.807-815
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• 2001

Two-dimensional (2D) correlation method, which generates the synchronous and the asynchronous 2D spectrum by complex cross correlation of the Fourier transformed spectra, is an analysis method for the changes of the sample spectrum induced by vari ous perturbations. In the present work, the 2D electronic correlation spectra have been simulated for the cases where the sample spectrum composed of two gaussian bands changes linearly. When only the band amplitudes of the sample spectrum change, the synchronous spectrum shows strong peaks at the band centers of the sample spectrum, but the asynchronous spectrum does not make peaks. When the sample spectrum shifts without changing intensity and width, the synchronous spectrum shows peaks around the initial and final positions of the band maximum and the asynchronous spectrum shows long peaks spanning the shifting range. The band width change produces the complex 2D correlation spectra. When the sample spectrum shifts with band broadening, the width change by 50% of full width at half maximum (FWHM) does not give so large an effect on the correlation spectrum as the spectral shift by one half of FWHM of the sample spectrum.

• Structural Engineering and Mechanics
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• v.18 no.2
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• pp.231-246
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• 2004

In this paper, a comparison of various random vibration and deterministic dynamic analyses of cable-stayed bridges subjected to asynchronous ground motion is presented. Different random vibration methods are included to determine the dynamic behaviour of a cable-stayed bridge for various ground motion wave velocities. As a numerical example the Jindo Bridge located in South Korea is chosen and a 413 DOF mathematical model is employed for this bridge. The results obtained from a spectral analysis approach are compared with those of two random vibration based response spectrum methods and a deterministic method. The analyses suggest that the structural responses usually show important amplifications depending on the decreasing ground motion wave velocities.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.2
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• pp.53-61
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• 2021

Purpose : The purpose of this study is to explore the effectiveness of online blended learning(asynchronous online learning class 1+synchronous online learning class 2) method and discuss the applicability of online blended learning. In this study, we will analyze the differences in class satisfaction and academic achievement between asynchronous online learning and online blended learning classes, and discuss the strengths, weaknesses, and satisfactions of online blended learning. Methods : The subjects of this study were 39 of the occupational therapy students who took the 'child development' course. Asynchronous online learning class was applied for 1-6 weeks and online blended learning was applied for 9~14 weeks. The online blended learning class consisted of 1 hours synchronous online learning and 2 hours asynchronous online learning. For the asynchronous online learning, the screen recording program of OBS Studio was used, and for the synchronous online learning, the Zoom program was used. The results of course evaluation and academic achievement of students according to the type of lecture were compared, and a survey was conducted on the satisfaction of online blended learning. Results : The results of this study are as follows. First, satisfaction(A class: t=-4.19, p=.001, B class: t=-7.94, p=.00) with online blended learning classes was significantly higher than asynchronous online learning. Second, when applying online blended learning class, academic achievement(t=-10.58, p=.00) was significantly higher. Third, the online blended learning class showed the highest satisfaction in improving the interest in the subject, and it was found to be helpful in online class management, professor-student interaction, and class content understanding. Conclusion : We have found that online blended learning can compensate for the shortcomings of online lectures and increase the quality of the lectures and the satisfaction of students. The application of online blended learning should be supplemented according to the characteristics of each class, and I hope that blended online teaching methods can be developed based on new ideas in the future.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.195-204
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• 1996

We suggest a transform method form asynchronous finite state machines (AFSMs) into signal transition graphs (STGs) for speed-independent circuit synthesis. Existing works synthesize nodes in the state graph increases exponentially as the number of input and output signals increases. To overcome the problem of the exponential data complexity, we transform AFSMs into STGs so that the previous synthesis algorihtm form STGs can be applied.Accoridng to the experimental results, it turns out that our synthesis method produces more efficient circuit than the previous synthesis methods.