• KSII Transactions on Internet and Information Systems (TIIS)
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• v.15 no.4
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• pp.1389-1408
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• 2021

Proof-of-Work (PoW) is the first and still most common consensus protocol in blockchain. But it is costly and energy intensive, aiming at addressing these problems, we propose a consensus algorithm named Proof-of-Work-and-Block-Compression (PoW-BC). PoW-BC is an improvement of PoW to compress blocks and adjust consensus parameters. The algorithm is designed to encourage the reduction of block size, which improves transmission efficiency and reduces disk space for storing blocks. The transaction optimization model and block compression model are proposed to compress block data with a smaller compression ratio and less compression/ decompression duration. Block compression ratio is used to adjust mining difficulty and transaction count of PoW-BC consensus protocol according to the consensus parameters adjustment model. Through experiment and analysis, it shows that PoW-BC improves transaction throughput, and reduces block interval and energy consumption.

• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.103-112
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• 1999

We have investigated the solar activity variation with period shorter than 1000 days, through Fourier transformation of solar cycle 21 and 22 data. And real time predictions of the flare maximum intensity have been made by multilinear regression method to allow the use of multivariate vectors of sunspot groups or active region characteristics. In addition, we have examined the evolution of magnetic field and current density in active regions at times before and after flare occurrence, to check short term variability of solar activity. According to our results of calculation, solar activity changes with periods of 27.1, 28.0, 52.1, 156.3, 333.3 days for solar cycle 21 and of 26.5, 27.1, 28.9, 54.1, 154, 176.7, 384.6 days for solar cycle 22. Periodic components of about 27, 28, 53, 155 days are found simultaneously at all of two solar cycles. Finally, from our intensive analysis of solar activity data for three different terms of $1977\~1982,\; 1975\~1998,\;and\;1978\~1982$, we find out that our predictions coincide with observations at hit rate of $76\%,\;63\%$, 59 respectively.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.483-493
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• 2022

It is important to improve the efficiency of plant breeding and crop yield to fulfill increasing food demands. In plant phenotyping studies, the capability to correlate morphological traits such as plant height, stem diameter, leaf length, leaf width, leaf angle and size of panicle of the plants has an important role. However, manual phenotyping of plants is prone to human errors and is labor intensive and time-consuming. Hence, it is important to develop techniques that measure plant phenotypic traits accurately and rapidly. The aim of this study was to determine the feasibility of point cloud data based on a 3D light detection and ranging (LiDAR) system for plant phenotyping. The obtained results were then verified through manually acquired data from the sorghum samples. This study measured the plant height, plant crown diameter and the panicle height and diameter. The R² of each trait was 0.83, 0.94, 0.90, and 0.90, and the root mean square error (RMSE) was 6.8 cm, 1.82 cm, 5.7 mm, and 7.8 mm, respectively. The results showed good correlation between the point cloud data and manually acquired data for plant phenotyping. The results indicate that the 3D LiDAR system has potential to measure the phenotypes of sorghum in a rapid and accurate way.

• Korean Journal of Adult Nursing
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• v.14 no.2
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• pp.296-305
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• 2002

Purpose: The purpose of this research was to describe how nurses in intensive care units (ICU) work. Method: A total of 18 ICU nurses participated in the research. The data was collected through individual in-depth interviews and analyzed by grounded theory method using NUDIST 4.0 software program. Results: Three different patterns regarding nursing performance among ICU nurses were identified. These are 1) nursing performance of nurses who perform excellently, 2) nursing performance of nurses who do not perform well because of their lack of experience, and 3) nursing performance of nurses who do not perform well in spite of their good years of experience. These three different nursing performances were described in terms of seven different categories; 1) assessing and monitoring nursing problems, 2) clinical decision making, 3) interpersonal relationships, 4) holistic care, 5) technical skills, 6) problem solving, 7) working independently and creatively. This study also identified two intervening factors that influenced the advancement of their expertise. Conclusion: The results of this study might help nurse managers in developing continuing educational programs for inexperienced nurses or those nurses not performing well to become experts by a deeper understanding of the nature of nursing performance and the factors that influence nursing performance in ICU settings.

• ETRI Journal
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• v.24 no.1
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• pp.1-11
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• 2002

A video summary abstracts the gist from an entire video and also enables efficient access to the desired content. In this paper, we propose a novel method for summarizing news video based on multimodal analysis of the content. The proposed method exploits the closed caption data to locate semantically meaningful highlights in a news video and speech signals in an audio stream to align the closed caption data with the video in a time-line. Then, the detected highlights are described using MPEG-7 Summarization Description Scheme, which allows efficient browsing of the content through such functionalities as multi-level abstracts and navigation guidance. Multimodal search and retrieval are also within the proposed framework. By indexing synchronized closed caption data, the video clips are searchable by inputting a text query. Intensive experiments with prototypical systems are presented to demonstrate the validity and reliability of the proposed method in real applications.

• Journal of Korean Clinical Health Science
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• v.4 no.1
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• pp.510-521
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• 2016

Purpose. The aim of this study was to provide Aromatherapist with analysis of correlation between MBTI personality type and scent preference of natural aroma essential oil in university students. Methods. Data was analyzed by students whom participated in the research on the scent preference of natural aroma essential oil of students from m university who accomplished to MBTI personality survey. Results. As a result, the introverted personality types more liked Peppermint and felt more intensive scent than extroverted personality types did(p=0.006). Extroverted personality types recognized Neroli as feminine scent(p=0.034) and introverted personalty types recognized Frankincense as feminine scent(p=0.045). Extroverted personality types felt that Juniper berry is exciting scent(p=0.036) and that Rosemary(p=0.044) and Lavender(p=0.030) are eco-friendly scent. And introverted personality types relatively less did than extroverted personality types. Conclusions. This study is to get a basic data of aroma preference of university students by looking into the influence that MBTI personality type affect natural aroma preference and to use this data for ease off school stress and job seekng stess and counsel the students.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.11
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• pp.1033-1039
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• 2020

Vietnam is conducting an export-led growth model and labour-intensive industries contributing majorly to the total export value. In the context of Industry 4.0, the labour-based industries are significantly affected; hence, enhancing productivity is the key measure to maintain these industries. The garment industry contributes significantly to the total export value of Vietnam. Based on meta-frontier framework, the approach of data envelopment analysis is used to measure technical efficiency of Vietnamese garment firms and the global Malmquist TFP index is utilised to identify productivity change and its components including efficiency, technology and technical gaps between different groups of firms. The data of Vietnamese garment firms from 2013 to 2018 collected from the Vietnam General Statistic Office is used in this study. The results show that: (i) The total factor productivity of Vietnamese garment firms growth, technical progress is the main contributor; (ii) The private garment sector is the leading group; (iii) There is a large technological gap among Vietnamese garment sectors. The private and FDI garment firms have experienced a growth in all components of total factor productivity change. Meanwhile, technological progress change is the main reason to constrain the productivity growth of state-owned garment firms.

• Publications of The Korean Astronomical Society
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• v.14 no.2
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• pp.91-102
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• 1999

We have made intensive calculations on the maximum relative sunspot number and the date of solar maximum of 23rd solar cycle, by using the statistical and precursor methods to predict solar activity cycle. According to our results of solar data processing by statistical method, solar maximum comes at between February and July of 2000 year and at that time, the smoothed sunspot number will reach to $114.3\~122.8$. while precursor method gives rather dispersed value of $118\~17$ maximum sunspot number. It is found that prediction by statistical method using smoothed relative sunspot number is more accurate than by any method to use any data of 10.7cm radio fluxes and geomagnetic aa, Ap indexes, from the full analysis of solar cycle pattern of these data. In fact, current ascending pattern of 23rd solar cycle supports positively our predicted values. Predicted results by precursor method for $Ap_{avg},\;aa_{31-36}$ indexes show similar values to those by statistical method. Therefore, these indexes can be used as new precursors for the prediction of 23rd or next solar cycle.

• Proceedings of the Korean Information Science Society Conference
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• 2001.04a
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• pp.100-102
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• 2001

Intensive I/O bandwidth demand of the multimedia streaming service puts significant burden on file system. Different from the legacy text based or image data, the semantics of the data in multimedia format can be significantly affected if the data block is not delivered by the predefined deadline. The legacy file system used in Unix or Unix like environment is designed to efficiently handle the files who sizes range from few hundreds of byte to several tens of gigabytes. This fundamental design philosophy results in the file system based on multi level skewed tree structure. Multi level i-node structure has significant drawback when the application performs sequential read operation. In this article, we present the result of the performance study of the file system which is specifically designed for handling multimedia streams. We implemented the file system on Linux Operating System environment and examines the performance behavior of the file system under streaming I/O workload. The result of the study shows that the proposed file system performs much more efficiently than the ext2 file system of Linux does.

• Korean Journal of Adult Nursing
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• v.20 no.3
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• pp.365-374
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• 2008

Purpose: This study was conducted to evaluate quality of sleep and to assess the factors that influence quality of sleep in surgical ICU. Methods: The subject of the study were consisted 109 adult patients who admitted to surgical ICU. The data were collected from May 20 to December 10, 2007 by structured questionnaires. The data were analyzed with descriptive analysis, paired t-test, Pearson correlation coefficient and stepwise multiple regression. Results: The score of quality of sleep was 4.57 point. The main sleep disturbance factors related to quality of sleep in surgical ICU inpatient were sleep time, machinery alarm and noise(adjusted $R^2$=33.2). Conclusion: Based on the finding of this study, it is needed to develop a nursing intervention program that including to promote quality of sleep and to decrease machinery alarm and noise in surgical ICU.