• Molecules and Cells
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• v.44 no.12
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• pp.861-878
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• 2021

The human genome contains many retroviral elements called human endogenous retroviruses (HERVs), resulting from the integration of retroviruses throughout evolution. HERVs once were considered inactive junk because they are not replication-competent, primarily localized in the heterochromatin, and silenced by methylation. But HERVs are now clearly shown to actively regulate gene expression in various physiological and pathological conditions such as developmental processes, immune regulation, cancers, autoimmune diseases, and neurological disorders. Recent studies report that HERVs are activated in patients suffering from coronavirus disease 2019 (COVID-19), the current pandemic caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) infection. In this review, we describe internal and external factors that influence HERV activities. We also present evidence showing the gene regulatory activity of HERV LTRs (long terminal repeats) in model organisms such as mice, rats, zebrafish, and invertebrate models of worms and flies. Finally, we discuss several molecular and cellular pathways involving various transcription factors and receptors, through which HERVs affect downstream cellular and physiological events such as epigenetic modifications, calcium influx, protein phosphorylation, and cytokine release. Understanding how HERVs participate in various physiological and pathological processes will help develop a strategy to generate effective therapeutic approaches targeting HERVs.

• Journal of Information Technology Applications and Management
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• v.20 no.3_spc
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• pp.259-278
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• 2013

At the center of the repeating evolution of IT industry, there is mobile computing in the ubiquitous environment, and the increasing usage of smart phones contribute more to its growth. P corporation co-developed with Google and implemented smart work system called SWP for the purpose of 'communication and collaboration with co-workers' beyond the general goal of increasing productivity and comfort of employees. The primary objective of this study is to objectively analyze the influence of the effect factor from end user's perspective and user satisfaction on SWP usage, intention for continuous usage and individual performance. To accomplish this research purpose, this study established research models and hypothesis by collective review about information system success models, and tested the research hypotheses using the structural equation modeling technique by data collected from 320 SWP system users of P corporation. Variations for system satisfaction evaluation standard are 1)SW system usage 2) intention for continuous usage 3) individual performance, effect variations are 1) social factors 2) technical factors 3) combination of social and technical factors. Therefore, this study is about influence factors on success of SWP system and how the factors impact the outcome. The test results of this research model is summarized as follows. Firstly, system user's satisfaction had positive impact on all three; SWP system usage, intention for continuous usage and individual performance. Secondly, social factor 'SWP control system' and technical factor 'information quality' and 'system quality' had positive impact on SWP system user satisfaction, while social factor 'shared value' and technical factor 'service quality' did not have significant effect on user satisfaction. Shared value however, had interactive effect with 'information quality' and 'service quality'. This study is expected to contribute to spread of academic research on smart work system by suggesting a model that can show important factors for corporation while explaining the successful implementation of SWP and its continuous usage.

• Journal of Drive and Control
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• v.13 no.2
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• pp.34-41
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• 2016

Unlike the commonly used On/Off solenoid, constant attraction force which is independent of plunger displacement is a considerably important characteristic to proportional solenoid of the EPPR Valve. Attraction force uniformity is mainly affected by the internal shape design parameters. Due to a number of shape design parameters, the optimal parameter values are very complex and time consuming to find by trial and error method. Much research has been conducted or are still in progress to find the optimal parameter values by applying various optimization techniques like Genetic Algorithm, Evolution Strategy, Simulated Annealing, or the Taguchi method. In this paper, the design parameters which have primary effects on the attraction force uniformity and the average attraction force are decided by main effects analysis of Design of Experiments. Optimal parameter values are derived using finite-element analysis and a neural network model.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.11
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• pp.12-20
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• 2013

Even though extensive research results have been applied to wireless cellular systems to improve their capacity and coverage, severe performance degradation experienced in cell boundary areas still remains as a major limiting factor to prohibit further improvement of user equipment (UE) throughput. In the Long Term Evolution-Advanced (LTE-A) standard of the Third Generation Partnership Project (3GPP), Some advanced techniques have been introduced to overcome this "cell-edge problem", including coordinated multipoint transmission and reception (CoMP) and inter-cell interference coordination (ICIC). In this paper, we propose yet another strategy to improve the performance of low-tier UEs by using the concept of multiple beam direction patterns (BDPs). Such multiple BDPs can be implemented using multi-layer antenna arrays stacked vertically at base station (BS) sites to transmit signals in different main beam directions. In comparison to conventional three-sector antennas with a fixed beam pattern, the proposed methods makes signal transmission in a rotational fashion to significantly enhance the reception quality of UEs located near sector (or cell) edge areas, preventing the situation where certain UEs are marginally covered by the BS for the whole transmission time. Performance evaluation results show that the proposed scheme outperforms the conventional three-sector transmission by 171% in low 5% UEs in terms of the UE throughput.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.3
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• pp.156-169
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• 2016

The objective of this study is to investigate patent trends of Daegu city which tries to introduce environment friendly energy and to develop new technology or new industry sprung from technology convergence on smart decentralized energy technology and other technologies. After applying network analysis to corresponding groups of technology or industry convergence, strategy for future energy convergence industry is provided. Patent data applied in Daegu city area are used to obtain research goal. The technology which contains several IPC codes (IPC Co-occurrence) is considered as a convergence technology. Path finder network analysis is used for visualizing and grouping by using IPC codes. The analysis results categorized 13 groups in energy convergence industry and reclassified them into 3 cluster groups (Smart Energy Product Production Technology Group, Smart Energy Convergence Supply Technology Group, Smart Energy Indirect Application Technology Group) considering the technical characteristics and policy direction. Also, energy industry has evolved rapidly by technological convergence with other industries. Especially, it has been converged with IT industry, and there is a trend that energy industry will be converged with service industry and manufacturing industry such as textile, automobile parts, mechanics, and logistics by employing infrastructure as well as network. Based on the research results on core patent technology, convergence technology and inter-industry analysis, the direction of core technology research and development as well as evolution on decentralized energy industry is identified. By using research design and methodology in this study, the trend of convergence technology is investigated based on objective data (patent data). Above all, we can easily confirm the core technology in the local industry by analyzing the industrial competitiveness in the macro level. Based on this, we can identify convergence industry and technology by performing the technological convergence analysis in the micro level.

• Journal of Cadastre & Land InformatiX
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• v.44 no.1
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• pp.1-15
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• 2014

This paper, at first, intends to develop a conceptual model of spatial information eco-system based on the related literature reviews. The basic requirements in constructing the model are also specified. Next, the functional roles and interrelationships among the actors constituting the eco-system are analyzed to investigate the major reasons of inefficient and unsmooth flows of value-added process of Korean spatial information industry. Especially, the Korea Cadastral Survery Corp.(KCSC), which has dual organizational characteristics of public and private entity, is analyzed to be positioned as the most dominant actors in the eco-system. However, the KCSC needs to be changed and challenged to re-establish the missions and institutional roles for upcoming network societies. Here, we proposed 4 future-oriented development strategies and action plans to promote the Korean spatial information industry and to activate the eco-system.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.24-36
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• 2008

Architecture-based competition has become a very important issue in many industries. As companies seek lower cost, fast development, and more customizability at the same time, modular architecture of products and processes seem to be an inevitable choice. Existing literature, however, has only focused on the basic contents of architecture-based competition. Different competitive environments and technological competencies of incumbent companies influence the evolutionary dynamics of dominant architecture of industries. In this paper we suggest a new theoretical framework to deal with the complex co-adaptation process of architecture-based competition. We first explore the emerging modular architecture in Chinese commercial vehicle industry, and then compare it with the architecture strategies of Korean companies. Based on the explorative case study, we propose new hypotheses relating the market demand, technological competencies of major players and dominant architecture in an indus-try.

• Journal of Sensor Science and Technology
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• v.30 no.6
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• pp.369-375
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• 2021

In this study, heterogeneous ZnO/CNTF composites were developed to improve the NO₂-sensing response, facilitated by the self-heating property. Highly conductive and mechanically stable CNTFs were prepared by a wet-spinning process assisted by the liquid crystal (LC) behavior of CNTs. Metal-organic frameworks (MOFs) of ZIF-8 were precipitated on the surface of the CNTF (ZIF-8/CNTF) via one-pot synthesis in solution. The subsequent calcination process resulted in the formation of the ZnO/CNTF composites. The calcination temperatures were controlled at 400, 500, and 600 ℃ in an N₂ atmosphere to confirm the evolution of the microstructures and NO₂-sensing properties. Gas sensor characterization was performed at 100 ℃ by applying a DC voltage to induce Joule heating through the CNTF. The results revealed that the ZnO/CNTF composite after calcination at 500 ℃ (ZnO/CNTF-500) exhibited an improved response (R_air/R_gas = 1.086) toward 20 ppm NO₂ as compared to the pristine CNTF (R_air/R_gas = 1.063). Selective NO₂-sensing properties were demonstrated with negligible responses toward interfering gas species such as H₂S, NH₃, CO, and toluene. Our approach for the synthesis of MOF-driven ZnO/CNTF composites can provide a new strategy for the fabrication of wearable gas sensors integrated with textile materials.

• The Journal of Korean Academic Society of Nursing Education
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• v.9 no.1
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• pp.144-154
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• 2003

Recently, in the academic disciplines critical thinking has been emphasized as the new evolution in education. Problem-based learning is suggested as the evolutionary learning method in developing critical thinking. In the nursing education, PBL is offered as an appropriate teaching method to prepare nurse student for professional. PBL is a student-centered learning strategy aimed at developing critical thinking, motivating self-directed study and attaining autonomy. The purpose of this study was to develop the communication curriculum of nursing education based on PBL and implementing of it. PBL module was developed focused on five communication situations. And learning strategies to facilitate the learning process and the guided questions to stimulate student inquiry were also developed. This PBL education was conducted for six students in the master's course during the 14 weeks from March, 2000 to June, 2000. The outcomes of the PBL education were examined based on the content analysis of the students reflective journal. As a result, it was found that students experienced the effect of it focused on self-oriented, group-oriented, and practice-oriented domain. In the self-oriented domain, the findings indicate that there were 5 kinds of concepts including 'motivation for self-directed study', 'transition toward certainty in knowledge acquisition', 'attempt to apply their prior knowledge into new situation', 'enhancement of self-image in real situation', 'self-growth with self reflection'. In the group-oriented domain, there were 3 kinds of concepts including 'cognitive work in group', 'perception of co-responsibility in attaining learning objectives', 'socialization with group members'. In the practice-oriented domain, there were 3 kinds of concepts including 'linkage theoretical knowledge with real situation', 'attempt to apply in real situation', 'development problem solving skill in real situation'. In conclusion, PBL had a significant effect on self, group, and clinical domain. And assessing PBL outcomes is challenging because standardized instrument do not develop yet. So the findings of this study can suggest the basic data for examining the PBL outcome.