• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.24 no.9
• /
• pp.1117-1122
• /
• 2020

The improving performance and utilizing application fields of mobile devices are getting bigger and wider. With this trend, applications that use database engines on mobile devices are also becoming common. Applications requiring mobile databases include mobile server databases, edge computing, fog computing, and the like. By the way, the most representative and widely used mobile database is SQLite3. In this paper, we test and compare the update performance of SQLite3 by some file systems. The update performance of the file systems in the mobile environment is an important performance factor in the limited H/W environment. The comparison file system was chosen as FAT, Ext2, and NTFS. Under the same conditions, experiments with each file system to test update performance and characteristics were processed. From the experimental results, we could analyze the advantages and disadvantages of each file system for each database update pattern.

• Journal of muscle and joint health
• /
• v.29 no.3
• /
• pp.218-227
• /
• 2022

Purpose: This study aimed to describe the current level of physical activity (PA) and to explore the relationships between self-efficacy for PA, perceived health status (PHS), attitudes toward aging, ego-integrity and PA in community-dwelling older Koreans. Methods: A total of 164 participants were recruited from community centers, churches, and senior welfare centers in Korea. With questionnaires, a survey was conducted from June 3rd to 22th, 2016. Data were analyzed with descriptive statistics, independent t-test, one-way ANOVA and Pearson's correlation coefficient using SPSS/WIN 22.0 program. Results: The mean amount of total PA was 5,295.33±6,272.38 MET/min/week. The number of subjects engaged in vigorous, moderate, and low-intensity activities were 87 (53.0%), 45 (27.4%), and 32 (19.5%), respectively. Overall, physical activities were different according to the presence of spouse (t=-2.79, p=.006) and the presence of housemate (t=2.03, p=.044). The mean scores of self-efficacy for PA, PHS, attitudes towards aging, and ego-integrity were 17.16±4.45, 9.00±2.41, 68.12±9.28 and 51.62±7.59, respectively. There were significant positive correlations between overall PA and self-efficacy for PA (r=.34, p<.001), PHS (r=.23, p=.003), attitudes towards aging (r=.26, p=.001). Conclusion: Specific programs to promote physical activities in addition to continuous education for improving self-efficacy for PA, PHS, and attitudes towards aging in community-dwelling older adults are needed.

• Composites Research
• /
• v.35 no.6
• /
• pp.456-462
• /
• 2022

Since natural fibers are highly flammable, it is not easy to make them flame retardant. In this study, a liquid flame retardant based on phytic acid, APTES, and Thiourea, which are flame retardant candidates derived from nature, was prepared and its performance was verified through flame retardant treatment and flame retardancy evaluation of bamboo fibers. When a liquid flame retardant is used, it is possible to treat a large amount of natural fibers with flame retardant treatment. Nine types of flame-retardant treated bamboo fibers were prepared according to the Taguchi design of experiment method. Thereafter, vertical burning test and microcalorimeter test were performed for flame retardancy evaluation, and the surface of natural fibers before and after flame-retardant treatment was compared using scanning electron microscope. The results show that phytic acid has a significant effect on improving the flame retardancy of natural fibers. Through microstructure analysis, it was assumed that the phytic acid helps flame retardant to uniformly adhere to the surface of natural fibers. If such research results are utilized, it is possible to make a large amount of natural fibers high flammability in an eco-friendly way, which is expected to be advantageous for the application of prototypes.

• The Transactions of the Korea Information Processing Society
• /
• v.2 no.6
• /
• pp.879-890
• /
• 1995

This paper proposes the shuttle protocol that can gather management information from managed systems in an efficient way. In this paper, we implement the protocol and evaluate the performance by simulation. The major feature of the shuttle protocol is a chained logical connection through managed systems, and management informations to be collected are circulated among specified managed systems in circular order on a logical ring connection. The data generated by an managed system are relayed to a neighbor managed system and the system sends its data which has additional management information to received data. Finally, a manager stationman get all of data generated by every managed system. we will show the analysis of management traffic patterns using conventional polling schemes and the shuttle protocol implementation viable to TCP/IP network and improving existing polling mechansims. Additionally, it is performed to evaluate the packet processing time and its distribution of a manager system and a gateway, and the queue length of packet and bit length of gateway against conventional polling schemes by simulation using OPNRT, a simulation-dedicated package.

• Journal of KIISE:Software and Applications
• /
• v.33 no.12
• /
• pp.1052-1061
• /
• 2006

This paper presents a method of using virtual examples to improve the classification accuracy for data with nominal attributes. Most of the previous researches on virtual examples focused on data with numeric attributes, and they used domain-specific knowledge to generate useful virtual examples for a particularly targeted learning algorithm. Instead of using domain-specific knowledge, our method samples virtual examples from a naive Bayesian network constructed from the given training set. A sampled example is considered useful if it contributes to the increment of the network's conditional likelihood when added to the training set. A set of useful virtual examples can be collected by repeating this process of sampling followed by evaluation. Experiments have shown that the virtual examples collected this way.can help various learning algorithms to derive classifiers of improved accuracy.

• Journal of Service Research and Studies
• /
• v.6 no.2
• /
• pp.51-64
• /
• 2016

This study is to find a service that improves the subjective happiness of cancer patients that receive radiation therapy. One hundred and one cancer patients undergoing radiation therapy were enrolled in the survey to verify the self-consciousness and symptom distress that could affect the subjective happiness. Independent t-test, one-way analysis of variance, and Pearson correlation were conducted with the SPSS 20.0 program. Symptom distress of cancer patients undergoing radiation therapy showed highest in the order of fatigue, appearance changes, dizziness, loss of appetite, and sleep disorders. And lower symptom distress, higher private self-consciousness were significantly correlated with higher subjective happiness among patients receiving radiation therapy for cancer. Study findings reflect the necessity of an integrative approach combining physical, psychological and emotional interventions during a radiotherapy period. For this cause, it would be necessary to supplement previously existing service programs and organize a patient-friendly system that could affiliate regional cancer centers or Public health centers with the hospitals in which the patients are being treated.

• Journal of the Korean Institute of Telematics and Electronics D
• /
• v.35D no.11
• /
• pp.10-22
• /
• 1998

In this paper, as a way of improving the availability and spectral efficiency of radio relay system, a co-channel radio relay system based upon the synchronous digital hierarchy is developed and its performance measured by 64-QAM with a never-seen multi-purpose ASIC chip is illustrated. This system provides a couple of transmission capacity compared with alternative channel arrangement. By adopting a powerful complex 13-tap adaptive time domain equalizer and cross-pol interference canceller, improvement of more than 1.5 ~ 2.0 dB in signature is obtained in comparison to 9 or 11-tap adaptive time domain equalizer, and about 22.5 dB in improvement factor of cross-pol interference canceller is achieved at C/N of 24.5 dB. In addition, digital filter makes it possible to optimize the occupied bandwidth by selecting an appropriate roll-off factor externally. It is expected that co-channel radio relay system with the powerful multi-purpose ASIC chip plays a key role in creating a value-added product, reliability, and reducing the outage time.

• Journal of Broadcast Engineering
• /
• v.22 no.5
• /
• pp.643-651
• /
• 2017

Steganography is one of information hiding technologies and discriminated from cryptography in that it focuses on avoiding the existence the hidden information from being detected by third parties, rather than protecting it from being decoded. In this paper, as an image steganography method which uses images as media, we propose a new block matching method that embeds information into the discrete wavelet transform (DWT) domain. The proposed method, based on a statistical analysis, reduces loss of embedding capacity due to inequable use of candidate blocks. It works in such a way that computes the variance of each candidate block, preserves candidate blocks with high frequency components while reducing candidate blocks with low frequency components by compressing them exploiting the k-means clustering algorithm. Compared with the previous block matching method, the proposed method can reconstruct secret images with similar PSNRs while embedding higher-capacity information.

• Convergence Security Journal
• /
• v.13 no.5
• /
• pp.215-222
• /
• 2013

This study aims to provide future direction recognizing the educational importance and to present the way ahead that practices correctly for improving an educational role on security sector to prevent child missing. Therefore, it was conducted with questionnaire that is "Research on participation grade of education to prevent child missing and the actual condition" made by researcher of this study which is on 363of parents of pre-chirdren of 6,7 and 8years old in a kindergarten and an elementary school where is located in metropolitan area. It operated to take processing enterprise statistics using SPSS/WIN 12.0 for getting data, and analyzed frequency and t-verification.It investigated correct selection of an education specialist on preventive education and participation grade of education to prevent missing on home, how often, how it is conducted, then what requirement for educationto prevent child missing and participation grade is, whether difference is in accordance with gender of parentsand gender of child.

• Proceedings of the Korean Society of Plant Biotechnology Conference
• /
• 2002.04a
• /
• pp.41-47
• /
• 2002

Adverse environmental conditions such as drought, high salt and cold/freezing are major factors that reduces crop productivity worldwide. According to a survey, $50-80\%$ of the maximum potential yield is lost by these 'environmental or abiotic stresses', which is approximately ten times higher than the loss by biotic stresses. Thus, Improving stress-tolerance of crop plants is an important way to improve agricultural productivity. In order to develop such stress-tolerant crop plants, we set out to identify key stress signaling components that can be used to develop commercially viable crop varieties with enhanced stress tolerance. Our primary focus so far has been on the identification of transcription factors that regulate stress responsive gene expression, especially those involved in ABA-mediated stress response. Be sessile, plants have the unique capability to adapt themselves to the abiotic stresses. This adaptive capability is largely dependent on the plant hormone abscisic acid (ABA), whose level increases under various stress conditions, triggering adaptive response. Central to the response is ABA-regulated gene expression, which ultimately leads to physiological changes at the whole plant level. Thus, once identified, it would be possible to enhance stress tolerance of crop plants by manipulating the expression of the factors that mediate ABA-dependent stress response. Here, we present our work on the isolation and functional characterization of the transcription factors.