• Korean Journal of Plant Resources
• /
• v.19 no.6
• /
• pp.706-715
• /
• 2006

Nitrate reductase deficient (NR) mutant lines were selected indirectly by their resistance to 100mM chlorate in cell cultures of P. parviflora. A total of 585 chlorate resistant lines were confirmed by a second passage on a high concentration of chlorate. Frequency of spontaneous mutation was $9.7{\times}10^{-7}$ in 3 month old suspension-cultured cells, and in non-selective media containing amino acids as sole nitrogen source. The frequency of mutation could be increased up to 11-fold by culture for 12 months. Out of 40 randomly selected calli, 22 were fully deficient in NR. The rest of the clones contained a decreased level of NR activity. Further characterization was carried out in 13 mutant lines which were fully deficient in NR and in 5 mutant lines containing residual (0-7.0%) NR activity, as compared to wild-type cells cultured on the same medium. The $NR^-$ mutants were tentatively classified as defective in the NR apoenzyme (nia-type; 11 mutant lines including the 5 with residual NR activity) or in the molybdenum cofactor (cnx-type; 7 mutant lines) by the XDH activity. The cnx-type could be further classified into two groups. In one group (5 mutant lines) of these, the NR activity could be partially restored by nonphysiologically high (1.0mM) molybdate in the culture medium. Both types of $NR^-$ mutants were unable to grow on minimal medium containing nitrate as sole nitrogen source, but grew well on amino acids. They also proved to be extremely sensitive to the standard medium ($MSP_1$) containing nitrate and ammonium. Shoot regeneration was obtained only in the $NR^-$ mutants, which contained residual NR activity, but they so far have failed to grow into plants.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.1
• /
• pp.213-218
• /
• 2011

The scope of homogeneous Lewis acid-catalyzed benzo[N,N]-heterocyclic condensation was expanded to include the use of various metal salts not reported in the literature and $SnCl_2{\cdot}2H_2O$ was finally selected. Among various solid supports activated with $SnCl_2$, heterogeneous $SnCl_2/SiO_2$ proved to be the most effective and significantly higher conversions were achieved compared to $SnCl_2{\cdot}2H_2O$ itself. The results of TG-DTA and BET indicated that dispersed $SnCl_2$ coordinates with surface hydroxyl groups of silica leading to formation of stable Lewis acid sites. Low catalyst loading, operational simplicity, practicability and applicability to various substrates render this eco-friendly approach as an interesting alternative to previously applied procedures.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2015.10a
• /
• pp.1035-1038
• /
• 2015

The video conference system which enables multiple users even at places away from each other proceed with the work at the same time is required to establish a convenient and efficient smart work environment. The conventional S/W-based video conference system is developed by the different implementation methods using provider's own technology and as a separate program for each OS type of user. On the other hand, the video conference system using HTML5 and WebRTC provides features of video conference system through a web browser that support HTML5 and WebRTC functions without installing any programs In this paper, in order to activate a HTML5-based video conference system in the domestic market, we propose the standard for the interworking functions that need to be supported in each system to ensure the interoperability among different HTML5-based video conference systems.

• Journal of Service Research and Studies
• /
• v.2 no.1
• /
• pp.39-46
• /
• 2012

It is growing in size of database in companies. This caused to develope data mining techniques to predictive information from the large database. Costs and other effects can give variety of sales exploding through the analysis of the differences. Analysis of the various classification techniques, various angle can be analyzed point of view of the area information. The analysis of rules and patterns associated with a large amount of useful information from the database can be analyzed effectively. Goods store were analyzed using association rules, one of the data mining analysis techniques. Through this type of existing products according to analyze customer buying patterns, data mining has been studied to establish strategic marketing analysis.

• The Plant Pathology Journal
• /
• v.31 no.4
• /
• pp.388-401
• /
• 2015

Sweet potatoes (Ipomea batatas L.) are grown extensively, in tropical and temperate regions, and are important food crops worldwide. In Korea, potyviruses, including Sweet potato feathery mottle virus (SPFMV), Sweet potato virus C (SPVC), Sweet potato virus G (SPVG), Sweet potato virus 2 (SPV2), and Sweet potato latent virus (SPLV), have been detected in sweet potato fields at a high (~95%) incidence. In the present work, complete genome sequences of 18 isolates, representing the five potyviruses mentioned above, were compared with previously reported genome sequences. The complete genomes consisted of 10,081 to 10,830 nucleotides, excluding the poly-A tails. Their genomic organizations were typical of the Potyvirus genus, including one target open reading frame coding for a putative polyprotein. Based on phylogenetic analyses and sequence comparisons, the Korean SPFMV isolates belonged to the strains RC and O with >98% nucleotide sequence identity. Korean SPVC isolates had 99% identity to the Japanese isolate SPVC-Bungo and 70% identity to the SPFMV isolates. The Korean SPVG isolates showed 99% identity to the three previously reported SPVG isolates. Korean SPV2 isolates had 97% identity to the SPV2 GWB-2 isolate from the USA. Korean SPLV isolates had a relatively low (88%) nucleotide sequence identity with the Taiwanese SPLV-TW isolates, and they were phylogenetically distantly related to SPFMV isolates. Recombination analysis revealed that possible recombination events occurred in the P1, HC-Pro and NIa-NIb regions of SPFMV and SPLV isolates and these regions were identified as hotspots for recombination in the sweet potato potyviruses.

• The Journal of the Korea Contents Association
• /
• v.18 no.12
• /
• pp.62-74
• /
• 2018

This study was proposed to examine the mediating effect of basic psychological needs on how parenting attitude affect middle school students with over-dependence on smart phone. This study utilized 2017 survey research by National Information Society Agency (NIA), namely a long-term follow-up study of 901 people with over-dependence on internet and smart phone. This study showed two findings. First, over-dependence on smart phone had correlations with basic psychological needs- autonomy(r=-.22, p<.001) and competence(r=-.13, p<.001); with parenting attitude- positive parenting(r=-.21, p<.001) and negative parenting(r=.15, p<.001). Second, both parenting attitude and basic psychological needs had a causal relationship with over-dependence on smart phone. These results can provide a basis to reconsider social awareness on over-dependence on smart phone among middle school students. This study proposed few research directions for further study to prevent over-dependence on smart phone and to educate parents.

• The Journal of the Korea Contents Association
• /
• v.19 no.4
• /
• pp.345-358
• /
• 2019

The purpose of this study is to develop the Internet vulnerability index of adolescents. To do this, we used the original data of long - term follow - up survey for the internet overdependency cause analysis conducted by NIA in 2018, and analyzed the correlation between alternatives of internet vulnerability index and personal psychology by using linear regression analysis. Factor analysis showed that the relationship with the surroundings was indexed by adding 9 items to positive factors such as family acceptance, peer attachment, and teacher favorability. The relationship between the surroundings and self - stigmatization is confirmed, and the relationship between the surroundings and the Internet fragility is predicted to be negatively related, and the digital capacity is also assumed to be negatively correlated with the Internet vulnerability. In order to develop the specific form of the Internet vulnerability index, personal psychology and linear regression analysis were conducted. As a result, positive factors and R value of personal psychology were increased when considering the relationship with the environment and the digital capacity rather than the Internet overdependency model. Based on these implications, we discussed the implications and limitations of this study.

• The Journal of Information Systems
• /
• v.30 no.1
• /
• pp.85-104
• /
• 2021

Purpose This study aims to verify the mediating effect of the utilization performance of digital device on the relationship between user attitude and life satisfaction. Design/methodology/approach Using the data of 2018 Digital Divide Survey conducted by the National Information Society Agency(NIA), the mediating effect was verified by Baron & Kenny (1986)'s 3 step process, targeting 1,662 adults older than 55. Findings The result is as follows: first, the user attitude of middle and older aged people has a positive effect on their life satisfaction. Second, the effect of user Attitude towards Digital Device of middle and older citizens is partially mediated by the utilization performance of digital device. The results of this study indicate that when providing informatization education in the local community to promote the use of digital devices for the elderly, efforts should be made to grasp the level and inclination of informatization individually, and furthermore present improvements for wireless devices that the elderly can easily access in their daily lives. This study is expected to be a groundwork for a practical intervention to boost positive attitude towards using digital device to enhance the utilization performance of digital device and the life satisfaction of middle and older aged people.

• Knowledge Management Research
• /
• v.21 no.4
• /
• pp.243-263
• /
• 2020

The purpose of this study is to propose the performance measurement model for open big data platform. In order to develop the performance measurement model, we have integrated big data reference architecture(NIST 2018) with performance prism model(Neely et al. 2001) in the platform perspective of open big data. Our proposed model consists of five key building blocks for measuring performance of open data platform as follows: stakeholder contribution, big data governance capabilities, big data service capabilities, big data IT capabilities, and stakeholder satisfaction. In addition, our proposed model have twenty four evaluation indices and seventy five measurement items. We believe that our model could offer both research and practical implications for relevant research.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2022.05a
• /
• pp.488-490
• /
• 2022

Recently, interest in industrial accidents such as the Industrial Safety and Health Act and the Serious Accident Punishment Act is increasing, and the demand for safety managers for safety management of workers in research institutes and industrial fields of various fields is increasing. For worker safety management, CCTVs are being installed in factories and workplaces, and workers are monitored to enhance safety management. In this paper, we intend to design a dangerous situation assessment system by constructing data using CCTV in such a workplace and modeling it in JSON format. The data modeling was produced by referring to the data set construction guide for artificial intelligence learning and the quality management guideline of the Korea National Information Society(NIA). Through this system, we want to check what kind of risk management exists in the workplace by risk situation scenario and use it to build a more systematic system.