• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.19-24
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• 2016

In Long Term Evolution-Advanced (LTE-A), small cell enhancement(SCE) has been developed as a cost-effective way of supporting exponentially increasing demand of wireless data services and satisfying the user quality of service(QoS). However, due to the dense and irregular distribution of a large number of small cells, the offloading scheme should be applied in the small cell network. In this paper, we propose an user offloading scheme for SCE in LTE-Advanced system. We divide the small cells into different clusters according to the reference signal received power(RSRP) from user equipment(UE). Within a cluster, We apply the user offloading scheme with the consideration of the number of users and interference conditions. Simulation results show that proposed scheme can improve the throughput, and spectral efficiency of small cell users. Eventually, proposed scheme can improve overall cell performance.

• Journal of the Institute of Electronics and Information Engineers
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• v.53 no.5
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• pp.13-18
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• 2016

In Long Term Evolution-Advanced (LTE-A), small cell enhancement(SCE) has been developed as a cost-effective way of supporting exponentially increasing demand of wireless data services and satisfying the user quality of service(QoS). However, there are many problems such as the transmission rate and transmission quality degradation due to the dense and irregular distribution of a large number of small cells. In this paper, we propose a clustering based interference management scheme in dense small cell network. We divide the small cells into different clusters according to the reference signal received power(RSRP) from user equipment(UE). Within a cluster, an almost blank subframe(ABS) is implemented to mitigate interference between the small cells. In addition, we apply the power control to reduce the interference between the clusters. Simulation results show that proposed scheme can improve Signal to Interference plus Noise Ratio(SINR), throughput, and spectral efficiency of small cell users. Eventually, proposed scheme can improve overall cell performance.

• The Journal of Information Systems
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• v.17 no.4
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• pp.233-260
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• 2008

Universities have recognized e-Learning Systems as the critical IT resources which contribute to improving the competitiveness of the universities as well as the quality of the traditional class-based lectures. Instructors deliver the main contents in the class. Other supplementary activities like online discussions, sharing of teaching-learning materials, submission of homeworks, communication among the learners and between the instructors and the learners, and so on can be efficiently facilitated using e-Learning Systems. In other words, e-Learning Systems enable a blended learning combined class-based lectures and e-learning in a variety of ways. Nonetheless, compared to the level of implementation of e-Learning Systems, the usage of both the instructors and the learners is not high. Accordingly, this study examines the determinants to affect on the usage of e-Learning Systems from the learners perspective. To draw the key determinants, we review the IS literatures related to adoption or use of the IS like Media Richness Theory (MRT), Technology Acceptance Model (TAM), Social Influence Model (SIM), and Self-efficacy Model. The variables are drawn out to be expected on the usage of e-Learning like Media Richness, Ease of Use from MRT, TAM and Instructor's Influence, Co-learner's Influence from SIM, and Self-efficacy. To test our model and hypotheses, we have collected data in the class-based lectures using e-Learning System complementary. The results of the test with 192 data are as follows: Firstly, it shows that the Instructor's Influence and the Media Richness are the influential determinants to affect on the Perception of Usefulness of e-Learning Systems. Additionally, the Co-learner's Influence and Ease of Use in order is significant to the Perception of Usefulness. Secondly, as to the degree of use of the e-Learning Systems, the Co-leaner's Influence, the Media Richness, and the Ease of Use are, in that order, the significant determinants. The Perception of Usefulness, also, founded a key factor on increasing the use of e-Learning Systems. On the other hand, the Instructor's Influence is not significant to the use of e-Learning Systems. Finally, it has been found that Self-efficacy is significant to the Perception of Media Richness, Ease of Use, but not significant to the Perception of Usefulness.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.12
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• pp.1814-1823
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• 2016

LVC(live-virtual-constructive) integrated training system is a representative cyber-physical system. Each systems in a LVC system has different time domain, resolution and operation methods. So, it is very important to integrate different middlewares as a common middleware for heterogeneous systems using inter-working GWs. Especially, since the LVC system uses different time, it is necessary to study the method for guaranteeing causality and time synchronization among the events from different systems. In this study, we propose an time synchronization scheme to integrate the virtual and constructive system which use the simulation time of HLA (High Level Architecture)/ RTI (Run Time Infrastructure) into the live system based on the OMG DDS (Data Distribution Service). We propose a precise time synchronization scheme based on HLA time management and clock federate between participants and federates which are the communication objects of DDS and HLA/RTI respectively. In addition, we verified that time is well-synchronized among heterogeneous systems using the suggested scheme by implementing and demonstrating simulation applications on each middleware.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.11
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• pp.2715-2720
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• 2014

Median filtering is very effective to remove impulse type noises, so it has been widely used in many signal processing applications. However, due to the time complexity of its non-linearity, median filtering is often used using a small filter window size. A lot of work has been done on devising fast median filtering algorithms, but most of them can be efficiently applied to input data with finite integer values like images. Little work has been carried out on fast 2-d median filtering algorithms that can deal with real-valued 2-d data. In this paper, a fast and simple median 2-d filter is presented, and its performance is compared with the Matlab's 2-d median filter and a heap-based 2-d median filter. The proposed algorithm is shown to be much faster than the Matlab's 2-d median filter and consistently faster than the heap-based algorithm that is much more complicated than the proposed one. Also, a more efficient median filtering scheme for 2-d real valued data with a finite range of values is presented that uses higher-bit integer 2-d median filtering with negligible quantization errors.

• KIPS Transactions on Software and Data Engineering
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• v.12 no.7
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• pp.303-314
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• 2023

Voice conversion, a technology that allows an individual's speech data to be regenerated with the acoustic properties(tone, cadence, gender) of another, has countless applications in education, communication, and entertainment. This paper proposes an approach based on the StarGAN-VC model that generates realistic-sounding speech without requiring parallel utterances. To overcome the constraints of the existing StarGAN-VC model that utilizes one-hot vectors of original and target speaker information, this paper extracts feature vectors of target speakers using a pre-trained version of Rawnet3. This results in a latent space where voice conversion can be performed without direct speaker-to-speaker mappings, enabling an any-to-any structure. In addition to the loss terms used in the original StarGAN-VC model, Wasserstein distance is used as a loss term to ensure that generated voice segments match the acoustic properties of the target voice. Two Time-Scale Update Rule (TTUR) is also used to facilitate stable training. Experimental results show that the proposed method outperforms previous methods, including the StarGAN-VC network on which it was based.

• Journal of Digital Convergence
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• v.14 no.11
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• pp.1-12
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• 2016

Rapid growth of information and communication technology and changes in college student characteristics require for university instructors to diversify instructional improvement efforts. Technological Pedagogical Content Knowledge (TPACK) is a capacity that instructors need to build for making instructional design based on consolidated technology. Accordingly this study explores instructors' awareness of the importance and performance of TPACK and to inquire into their relationships with epistemological beliefs and social support as relevant factors through a survey carried out with 264 instructors. The study has shown that there is a significant difference between college instructors' awareness of the importance of TPACK and their awareness of its performance. Furthermore, it has shown that the awareness of importance and performance of TPACK is significantly related to the social support, and that among the sub-factors of the social support, significant influences are observed from the emotional support on their awareness of the importance of TPACK and from the informational support on their awareness of the performance of TPACK. These results provide fundamental data for measures to develop and support TPACK capacity of college instructors, suggesting that it requires a teaching support strategy to enhance social support for instructors above all things.

• Journal of dental hygiene science
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• v.14 no.3
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• pp.356-363
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• 2014

This study attempts to measure the critical thinking disposition and problem-solving ability levels of dental hygiene students and to investigate their correlation. A self-administered survey was conducted with respect to dental hygiene students from three-year colleges in Busan, Ulsan and the Gyeongsangbuk-do region between April 2013 and May 2013. A total of 649 surveys were subject to a final analysis. Critical thinking disposition of the dental hygiene students resulted in a score of 3.20 out of a total of 5.0. Freshmen, students with high academic performance results, students with good interpersonal relations, students with a high level of satisfaction regarding major subject and clinical training and students with no clinical training experience showed a high score for critical thinking disposition. Problem-solving ability of the dental hygiene students resulted in a score of 3.06 out of a total of 5.0. Students with high academic performance results, students with good interpersonal relations and students with a high level of satisfaction regarding major subject and clinical training showed a high score for problem-solving ability. It was found that critical thinking disposition and problem-solving ability had a pure correlation. The critical thinking disposition appeared to problem solving, interpersonal relations, major factors affect satisfaction, was a critical thinking disposition, academic factors affect the ability to problem solve. Regarding education for dental hygiene students, the reinforcement of training to increase critical thinking and problem-solving abilities is necessary and the development of an educational curriculum and change in educational environment that can increase interpersonal skills and communication skills is necessary.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.1119-1126
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• 2023

This study measured the social value of social economy enterprises in Incheon Metropolitan City using the Social Value Index (SVI) developed by the Korea Social Enterprise Promotion Agency. The results showed that the social value orientation of the business activities of SSEs averaged 9.3 out of 15 points, and their innovation efforts were 8.0 out of 10 points. The average monetary and non-monetary social contribution efforts of SSEs was 5.1 out of 10. When comparing the average sales and social value scores by industry, the manufacturing sector shows that social enterprises have higher average sales and social value orientation of business activities, but lower social return efforts. Social work facility management and business support services have high average sales, but low social value orientation of business activities and efforts to make monetary or non-monetary social contributions. On the other hand, education services; arts, sports, and leisure-related services; and publishing, video, broadcasting, communication, and information services have lower average revenues but higher social value orientation of business activities. These SVI indicators are well utilized by local governments, but not yet by the central government. In the future, governments and public institutions should reflect the differences between sectors when formulating policies for social enterprises.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.18 no.2
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• pp.141-156
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• 2023

The advancement of Information and Communication Technology (ICT), along with the expansion of government and private investment in startup discovery and funding, has led to the emergence of startups seeking to generate outstanding results based on innovative ideas. As successful startups serve as role models, the number of aspiring entrepreneurs preparing to launch their own startups continues to increase. However, unlike entrepreneurs who challenge themselves with serial entrepreneurship after experiencing success, early-stage startups face various challenges such as team building, technology development, and fundraising. Accelerators play a dual role of mentor and investor by providing education, mentoring, consulting, network connection, and initial investment activities to help startups overcome various challenges they face and facilitate their growth. This study investigated whether there is a correlation between the characteristics of startups and their entrepreneurial performance, and analyzed whether accelerators mediate the relationship between startup characteristics and entrepreneurial performance. A total of 11 hypotheses were proposed, and a survey was conducted on 302 startup founders and employees located across the country, including the metropolitan area, for empirical research. SPSS 23.0 and Amos 23.0 were used for statistical analysis. Through this study, it was found that factors such as innovation, organizational culture, financial characteristics, and learning orientation among the characteristics of startups, rather than having a direct impact on entrepreneurial performance, are linked to entrepreneurial performance through the role of accelerators. By analyzing the impact factors of startup characteristics on entrepreneurial performance, this study presents research on the role of accelerators and provides institutional improvements. It is expected to contribute to the expansion of investment and differentiated acceleration programs, enabling startups to seize the market and grow stably in the market.