• Geomechanics and Engineering
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• v.18 no.6
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• pp.585-594
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• 2019

In-situ leaching could be one of the promising mining methods to extract the minerals from deep fractured rock mass. Constrained by the low permeability at depth, however, the performance does not meet the expectation. In fact, the rock mass permeability mainly depends on the pre-existing natural fractures and therefore play a crucial role in in-situ leaching performance. More importantly, fractures have various characteristics, such as aperture, persistence, and density, which have diverse contributions to the promising method. Hence, it is necessary to study the variation of fluid rate versus fracture parameters to enhance in-situ leaching performance. Firstly, the subsurface fractures from the depth of 1500m to 2500m were mapped using the discrete fracture network (DFN) in this paper, and then the numerical model was calibrated at a particular case. On this basis, the fluid flow through fractured rock mass with various fracture characteristics was analyzed. The simulation results showed that with the increase of Fisher' K value, which determine the fracture orientation, the flow rate firstly decreased and then increased. Subsequently, as another critical factor affecting the fluid flow in natural fractures, the fracture transmissivity has a direct relationship with the flow rate. Sensitive study shows that natural fracture characteristics play a critical role in in-situ leaching performance.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.71-78
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• 2019

The importance of social responsibility such as ethical management and social contribution activities is emphasized for the sustainable growth of companies. Although there is a great deal of research on corporate social responsibility due to the increase in social interest and expectation, most of them have been limited to research on general manufacturing industry. The purpose of this study is to analyze the effect of social responsibility activities on financial performance. In addition, we want to analyze the difference in the financial performance of companies with excellent social responsibility activities announced by the Institute of Economic Justice and others. The analysis period is from 2011 to 2016, and we analyze using the robust regression methodology which is relatively effective in solving the autocorrelation and this dispersion problem. First, it is proved that the higher the KEJI index, the more positive effect on financial performance. In addition, we found that there is a significant difference in the financial performance of companies with excellent social responsibility activities and those with other social responsibility activities. These results will have important implications for establishing a firm's financial strategy and will serve as useful information for the financial industry that is striving for sustainable management.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.1
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• pp.74-80
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• 1999

Recently, manufacturing work has been transformed to small scale production form with various types to act up to user's expectation from mass production with a little items required in the past. Then FMS using NC type machinaries has been applied actively also in domestic manufacturing line to meet thus tendency, but there are many machining troubles occured during work process not be settled yet. Nowdays high efficiently has been required no less than high precision in grinding work for the improvement of productivity. In this study, to represent more advance FMS can be adapted to thus situation In-process type monitoring method using AE and Current sensors is suggested to investigate the machining condition in grinding process. As results form this experimental study, it is recognized well that grinding conditions and dressing point of in time cab be estimated effectively using monitoring method suggested. Furthermore, surface shape of grinding wheel on voluntary point of in time can be predicted indirectly through the observation and comparison of AE signal waveform obtained as performance of continuous dressing work.

• Journal of Industrial Technology
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• v.22 no.B
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• pp.155-161
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• 2002

As the wireless communications are gradually developed, the higher frequency is demanded and the smaller the size of antenna shall be reduced by the wavelength of the operating frequency. However, the smaller the size of antenna becomes, the less the gain is obtained according to the frequency, so that a new attempt such as an array antenna has been examined to improve the characteristics. Also, for the convenience of communication, the omni-directional property is required. In this paper, two antennas system which is aligned in cross direction in tested and analyzed. The main scope is focused to get an appropriated distance between the two small antennas to get better properties. There are various ways of array arrangement, but in this study, it should be placed on the same PCB for easy implementation and the direction of each antenna are aligned to be a cross($90^{\circ}$) position. The study is carried out by comparing the radiation patterns mainly, and the theoretical expectation and the computer simulation are also executed. The final model is the folded IF-antennas system printed on PCB and the ideal dipole-antenna arrangement in also test to verify the possibility of our implementation. And it is finally proved by measuring experiments.

• Journal of Internet Computing and Services
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• v.14 no.4
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• pp.73-84
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• 2013

This study, based on flow theory and unified theory of acceptance and use of technology (UTAUT), examines various factors that influence the continuous use of mobile applications, particularly those providing users with satisfaction and pleasure as well as useful information. This study extends the previous studies that have been based on technology acceptance model, in which usefulness and ease of use are key determinants of use of new technology, by introducing flow theory in explaining the use of various technologies in mobile environment. For this purpose, this study employes a survey based field study and collects data from individuals who use fashion mobile apps since these are considered to provide fun and pleasures. This study finds that flow theory is a proper framework to understand the use of mobile technology, indicating flow experience is an important variable to determine the usage of fashion apps. In addition, performance expectation, effort expectation, social influence, and facilitation condition are found to be significant in influencing use of mobile apps, suggesting UTAUT still plays an important role in understanding the use of mobile technology.

• The Journal of Society for e-Business Studies
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• v.18 no.2
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• pp.205-222
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• 2013

One of the recent important issues in IT fields is the convergence. It had been simply focused on functional convergence of technologyies. However the convergence in terms of businesses or services also has been made in recent years. The convergence between broadcasting and telecommunication industries can be possible because the e-transformation of broadcasting industry based on digital technology such as multimedia and multi-channel, can be combined with the high speed telecommunication network. It is giving a birth of various convergence services such as IPTV. IPTV is a kind of new service that is combined with the convergence of network, contents, and device. Nevertheless the controversy about the scope and the value of this new convergence service has constantly been raised; for example, what is the difference between IPTV and Internet TV? or what are the benefits that customers can have? This study measured the expectation level and the cognitive level of users before and after using the service and analyzed the gap between the importance and the satisfaction of the service. From this study, we proposed the priority of each function by analysing Importance-Performance Analysis(IPA) method to suggest required functions of IPTV service based on N-Screen technology. This study will identify the gap of awareness level between service providers and end users for the functions of broadcasting and telecommunications convergence service and suggest a solution enhancing user satisfaction.

• Journal of information and communication convergence engineering
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• v.5 no.4
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• pp.339-345
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• 2007

Video transcoding is a technique used to convert a compressed input video stream with an arbitrary format, size, and bitrate into a different attribute video stream different attributes to provide a efficient video streaming service for the customers is dispersed in the heterogeneous networks. Specifically, frames deletion occur in a transcoding scheme that exploits the adjustment of frame rate, and at this time, the loss in temporal relation among frames due to frame deletion is compensated for the prediction of motion estimation by reusing motion vectors in the would-be deleted frames. But the processing time for transcoding don't have an improvement as much as our expectation because transcoding is done only within the transcoder. So in this paper, we propose a new transcoding algorithm based on prediction period to improve transcoding-related processing time. For this, we also modify the existing encoder so as to adjust dynamically frame rate based on the prediction period and deletion period of frames. To check how the proposed algorithm works nicely, we implement a video streaming system with the new transcoder and encoder to which it is applied. The result of the performance test shows that the streaming system with proposed algorithm improve 60% above in processing time and also PSNR have a good performance while the quality of pictures is preserved.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.46 no.3
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• pp.123-138
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• 2023

The Fourth Industrial Revolution and sensor technology have led to increased utilization of sensor data. In our modern society, data complexity is rising, and the extraction of valuable information has become crucial with the rapid changes in information technology (IT). Recurrent neural networks (RNN) and long short-term memory (LSTM) models have shown remarkable performance in natural language processing (NLP) and time series prediction. Consequently, there is a strong expectation that models excelling in NLP will also excel in time series prediction. However, current research on Transformer models for time series prediction remains limited. Traditional RNN and LSTM models have demonstrated superior performance compared to Transformers in big data analysis. Nevertheless, with continuous advancements in Transformer models, such as GPT-2 (Generative Pre-trained Transformer 2) and ProphetNet, they have gained attention in the field of time series prediction. This study aims to evaluate the classification performance and interval prediction of remaining useful life (RUL) using an advanced Transformer model. The performance of each model will be utilized to establish a health index (HI) for cutting blades, enabling real-time monitoring of machine health. The results are expected to provide valuable insights for machine monitoring, evaluation, and management, confirming the effectiveness of advanced Transformer models in time series analysis when applied in industrial settings.

• Journal of Information Technology Services
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• v.14 no.1
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• pp.195-215
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• 2015

Recently, as the number of smart-phone users has been rapidly increased, enterprise managers have a keen interest in business application of social media. Most previous studies have focused on perspective of the individual unit of analysis instead of enterprise level unit. The study is focused on the relationship between the enterprises' recognition and behavioral intention (and use) about social media application. The purpose of this study is to develop the model of small and medium enterprises' social media application, and to find the factors affecting their behavioral intention or use behavior. The moderating effects of four corporate characteristics on the relationship between the enterprises' recognition and behavioral intention are also examined. We surveyed 900 corporate staffs and received 203 responses. After questionnaires with unreliable responses had been excluded, 182 effective samples were used in the final analysis. The findings suggest that Performance Expectation, Social Influence, Facilitating Conditions significantly affect Behavioral Intention of social medea, and Behavioral Intention affects USE. Furthermore, some corporate characteristics have moderating effect on the relationship between recognition of social media and Behavioral Intention.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.1-18
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• 2021

The purpose of this study is to study the influencing factors that can affect the acceptance intention and acceptance behavior of the 4th Industrial Revolution and smart factory-related technologies by using the expanded UTAUT. Through this, by grasping which influencing factors affect the introduction and acceptance of related technologies, it is to derive strategies for responding to the fourth industrial revolution by manufacturing companies and accepting smart factory related technologies. A survey was conducted on various manufacturing companies, and 167 copies were used for research. As a result of the testing of research hypotheses, performance expectation, social impact, promotion conditions, network effect, and innovation have a positive (+) significant effect on acceptance intention. However, expectation of effort had a positive (+) effect on acceptance intention, but was not significant. Acceptance intention was tested to have a positive (+) significant effect on acceptance behavior. Therefore, factors that should be improved by individual manufacturing companies in the process of responding to the 4th industrial revolution and the introduction and acceptance of smart factory-related technologies are clearly presented.