• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.9
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• pp.1667-1671
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• 2015

Multi-level holographic data storage is a candidate for the next generation data storage system, since it can store more than one bit per pixel. It is possible to increase the number of codewords if the number of levels is increased, and the code with an appropriate selection of codewords can also increase the minimum distance. In this paper, we propose three multi-level modulation codes of the code rate 1 bit/pixel and compare the performance according to the minimum distance. The result shows that the code with small number of levels is better than that of large number of levels because it is hard to detect threshold value.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.65 no.4
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• pp.326-334
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• 2016

In this paper for developing and implementing the realtime HD level video streaming transmitter which is operated on the multi-platform in all network and client environment compared to the exist video live streaming transmitter. We design the realtime HD level video streaming transmitter supporting the multi-platform using the TMS320DM386 video processor of T.I company and then porting the Linux kernel 2.6.29 and implementing the RTSP(Real Time Streaming Protocol)/RTP(Real Time Transport Protocol), HLS(Http Live Streaming), RTMP(Real Time Messaging Protocol) that can support the multi-platform of video stream protocol of the received equipments (smart phone, tablet PC, notebook etc.). For proving the performance of developed video streaming transmitter, we make the testing environment for testing the performance of streaming transmitter using the notebook, iPad, android Phone, and then analysis the received video in the client displayer. In this paper, we suggest the developed the Realtime HD(High Definition) level Video Streaming transmitter performance data values higher than the exist products.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.27 no.12
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• pp.133-140
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• 2013

Cascaded H-Bridge multi-level inverters can be implemented through the series connection of single-phase modular power bridges. In recent years, multi-level inverters are becoming increasingly popular for high power applications due to its improved harmonic profile and increased power ratings. This paper presents a control method for balancing the dc-link voltage and ride-through enhancement, a modified pulse width-modulation Compensation algorithm of cascaded H-bridge multi-level inverters. During an under-voltage protection mechanism, causing the system to shut down within a few milliseconds after a power interruption in the main input sources. When a power interruption occurs finish, if the system is a large inertia restarting the load a long time is required. This paper suggests modifications in the control algorithm in order to improve the sag ride-through performance of ac inverter. The new proposed strategy recommends maintaining the DC-link voltage constant at the nominal value during a sag period, experimental results are presented.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.10a
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• pp.195-198
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• 2008

Recently, with the growth of photovoltaic system, many researchers and companies have concerned about the multi-level inverter which has an efficiency of boosting voltage. This paper implements a multi-level switching function based on the FPGA. It is efficient to implement the switching function based on the FPGA as a program able logic device. In order to implementation the switching function, this paper synchronized with the microprocessor through the clock and synchronous signal from the microprocessor.

• The Transactions of the Korean Institute of Power Electronics
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• v.12 no.2
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• pp.139-148
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• 2007

In this paper, we proposed the isolated multi-level inverter using 3-phase transformers. It makes possible to use a single DC power source due to employing low frequency transformers. In this inverter, the number of transformer could be reduced comparing with an exiting 3-phase multi-level inverter using single phase transformer. Also, using phase angle control method with switching frequency equal to output fundamental frequency, harmonics component of output voltage and switching losses can be reduced. Finally, we made a prototype inverter to clarify the proposed electric circuit and reasonableness of control signal.

• Journal of Korean Neurosurgical Society
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• v.45 no.6
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• pp.378-380
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• 2009

Osteoporotic patients who undergo percutaneous vertebroplasty (PVP) have the risk of a repeated collapse of their adjacent vertebral body due to alteration of load transfer into the adjacent vertebral body. The authors have experienced a rare case of repeated osteoporotic vertebral compression fractures (VCF) resulting in extreme multi-level PVP. A 74-year-old female developed severe back pain after slipping down one month ago. Her X-ray and MR images indicated a T11 VCF. She underwent successful PVP with polymethylmethacrylate (PMMA). Two weeks later, she returned to our hospital due to a similar back pain. Repeated X-ray and MR images showed an adjacent VCF on T12. A retrial of PVP was performed on T12, which provided immediate pain relief. Since then, repeated collapses of the vertebral body occurred 12 times in 13 levels within a 24-month period. Each time the woman was admitted to our hospital, she was diagnosed of newly developed VCFs and underwent repeated PVPs with PMMA, which finally eased back pain. Based on our experience with this patient, repeated multiple PVP is not dangerous because its few and minor complications. Therefore, repeated PVP can serve as an effective treatment modality for extreme-multi level VCFs.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.1
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• pp.373-385
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• 2022

Due to the lack of information, medical tourists are regarded to be at high risk. Prior medical tourism research has found that various types of perceived risks have a significant impact on medical tourists' purchase behavior. Even though medical tourism is predicted to increase, there is a lack of behavioral research to explain how perceived risks affect medical tourists' purchase behavior. In the context of Korean medical tourism, this study attempts to evaluate the effects of multi-level (macro, organizational, and personal) factors on medical tourists' perceived risks and purchase intentions. A conceptual model and hypotheses were built and empirically validated to investigate links between multi-level characteristics, perceived risks, and purchasing intentions. The data for this study was collected from Chinese tourists using a questionnaire. The impact of cognitive country image, affective country image, and medical service quality on fundamental risk is confirmed by statistical testing. Surprisingly, expectancy discrepancy risk is influenced only by cognitive country image and information search capabilities. Both fundamental and expectation discrepancy risks lower medical tourists' purchase intentions. The findings of this study show that a multi-level strategy is required to investigate the links between perceived risks and medical tourism purchasing intentions based on macro, organizational, and personal factors.

• The KIPS Transactions:PartB
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• v.11B no.6
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• pp.633-644
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• 2004

In this paper, we notice that the original NTSS algorithm can be proposed as the NTSS-3 Level algorithm by the multi-resolution technique. The fast block matching algorithm affects the speed by the patten combination and this paper proposes the block matching algorithm in different levels by multi-resolution technique, quite different from the original NTSS Patten. The block matching algorithm requires the multi-candidate to reduce the occurrence of low-image quality by the local minima problem. The simulation result compared to FS shows search speed 16 times quicker, and the PSNR 0.11-0.12［dB］ gets improved Image quality compared to the original fast block matching algorithm NTSS, and the speed is improved up to 0.1 times for improved image by the search point portion.

• Korean Journal of Child Studies
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• v.30 no.3
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• pp.23-36
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• 2009

Relationships between immigrant mothers' Korean language ability and preschoolers' language development in multi-cultural families were studied with 91 mothers and their children. Language capacity of mothers and children was measured by receptive and expressive vocabulary test, sentence comprehension test and two kinds of reading tests. Results showed that mothers' level of comprehension was relatively low but their reading ability was higher than that of elementary school first-grade Korean students. Comprehension of children in multi-cultural families with non-immigrant counterparts showed a lower level of language ability. Mother's level of expressive vocabulary, receptive vocabulary and reading ability correlated with children's language development. These results indicate a relationship between children's delayed language development in multi-cultural families and mother's low proficiency in Korean language.

• Journal of Home Health Care Nursing
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• v.24 no.2
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• pp.133-141
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• 2017

Purpose: This descriptive study aims to analyze the effects of the satisfaction level in the relationship between mother-in-law and daughter-in-law, conflicts between them, acculturative stress and stress coping strategies on elderly depression in multi-cultural families. Methods: The survey was conducted on 89 mothers-in-law, aged 65 or older, in multi-cultural families with a foreign daughter-in-law. Data were collected through structured questionnaires, and then were used to conduct t-test, ANOVA, correlation and multiple regression analyses using the statistical program SPSS 21.0. Results: This study found several factors contributing to depression of mothers-in-law in multi-cultural families. Those factors include living alone without a spouse, poor health, a high level of perceived discrimination and a passive reaction in terms of stress coping strategies. Conclusion: A sense of discrimination perceived by the mothers-in-law having a foreign daughter-in-law implies that the people around them and the community should make efforts to reject distorted perspectives and remove prejudice against foreign daughters-in-law. In addition, the mothers-in-law should receive education and training to use more active and positive stress coping strategies in a stressful situation with the foreign daughter-in-law.