• Journal of the Institute of Convergence Signal Processing
• /
• v.7 no.1
• /
• pp.17-23
• /
• 2006

In recent years, RFID has received much attention because of spread usage in industrial applications including factory, material flow, logistics and defense areas. However, there is only CRC-16 for error detection in ISO/IEC 18000-6 Protocols prepared for 860-960 MHz RFID, high error rates are expected in cases of high level of security and noisy envirionment. In this paper, we propose a usage of convolution code as a method for satisfying the high level of security requirement and system error performance.'1'he signal control function is implemented in a microprocessor with RF modulation and the convolutional encoding and Viterbi decoding are implemented in an FPGA chip.'The frame error rates are measured with and without convolution coding under the channel conditions of line-of- sight and non line-of-sight, respectively.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.40 no.7
• /
• pp.1387-1394
• /
• 2015

Along with the development of network transmission technology, the IPTV market is growing in fast pace. Additionally the UHD resolution broadcasting system along with user experience (UX) that provides better service to user has attracted attention recently since there are not enough research has been done with differentiated the UX that can enhance the UX yet. Therefore we proposed a low complexity syntax level image stitching implementation technique that run with multi-view services, which makes possibility to view multiple channel or video contents on the screen at the same time. Simulation results have demonstrated the liability and effectiveness of the proposed algorithm by showing that capability of generating more than 80 frames per second by stitching four Full-HD size videos into UHD frame.

• Journal of Digital Contents Society
• /
• v.17 no.5
• /
• pp.339-348
• /
• 2016

While the development of digital media has positive aspects of knowledge enlargement and a new communication channel, it also demonstrates a lot of unexpected defects, such as personal isolation, addiction, obsession or Attention Deficit Hyperactivity. Thus, the author considers it is urgent to develop the contents specifically designed for children in this new digital environment and would like to propose the combined Children's device and contents using the new concept of Mixed Reality. The Mixed Reality that mixes real world and virtual world provides the opportunity that can experience the new concept of play education by using touchable interface of children's real life toy cars together with the virtual world in the smart phones. This Mixed Reality that is extended from sole senses will lead the children to develop the concentration, sense of reality and imagination and also to experience the enlarged play and education concept.

• STI Policy Review
• /
• v.8 no.1
• /
• pp.41-61
• /
• 2017

The literature in research policy extensively addresses the interaction between public R&D and the society. Scholars have paid particular attention to the way science and technology are diffused into the society and industry with the aim of substantiating their potential value. In practice, having recognized the importance of the said interaction, R&D entities and governmental organizations promote scientific and technological innovations that result from their R&D activities. Yet, the nature of news media exposure as their primary channel to promote R&D outcomes has been remarkably understudied. Using the results of R&D projects supported by the National Research Foundation of Korea (NRF), this study examines R&D entities' strategic use of the news media to publicize their outcomes. The empirical results suggest that the scale of an R&D project positively affects the counts of media exposure of its R&D outcomes, whereas the level of technology readiness and the technology life-cycle do not have significant influence. In addition, the results suggest that, compared to senior researchers, young researchers are more likely to publicize their R&D outcomes and that R&D outcomes from highly ranked universities are more likely to be publicized than those from lower-ranking universities despite our control for R&D outcomes. The aforementioned results suggest that in promoting the diffusion of science and technology, especially to the public, policymakers should be concerned about incentives for those who provide techno-scientific information, such as researchers. The social need for the diffusion of techno-scientific information into the public (e.g., technology transfer and diffusion) is an insignificant factor in determining the media exposure of such information, whereas personal benefits and sensitive issues related to a researcher's own R&D activities (e.g., justification for R&D activities) drive researchers to publicize their R&D outcomes. This paper suggests that policymakers, especially those concerned with better diffusion of scientific and technological innovations need to design a proper incentive system to maximize the societal benefits of media exposure.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.394-394
• /
• 2013

The spin-orbit interaction has received great attention in the field of spintronics, because of its property and applicability. For instance, the spin-orbit interaction induces spin precession which is the key element of spin transistor proposed by Datta and Das, since frequency of precession can be controlled by electric field. The spin-orbit interaction is classified according to its origin, Dresselhaus and Rashba spin-orbit interaction. In particular, the Rashba spin-orbit interaction is induced by inversion asymmetry of quantum well structure and the slope of conduction band represents the strength of Rashba spin-orbit interaction. The strength of spin-orbit interaction is experimentally obtained from the Shubnikov de Hass (SdH) oscillation. The SdH oscillation is resistance change of channel for perpendicular magnetic field as a result of Zeeman spin splitting of Landau level, quantization of cyclotron motion by applied magnetic field. The frequency of oscillation is different for spin up and down due to the Rashba spin-orbit interaction. Consequently, the SdH oscillation shows the beat patterns. In many research studies, the spin-orbit interaction was treated as a tool for electrical manipulation of spin. On the other hands, it can be considered that the Rashba field, effective magnetic field induced by Rashba effect, may interact with external magnetic field. In order to investigate this issue, we utilized InAs quantum well layer, sandwiched by InGaAs/InAlAs as cladding layer. Then, the SdH oscillation was observed with tilted magnetic field in y-z plane. The y-component (longitudinal term) of applied magnetic field will interact with the Rashba field and the z-component (perpendicular term) will induce the Zeeman effect. As a result, the strength of spin-orbit interaction was increased (decreased), when applied magnetic field is parallel (anti-parallel) to the Rashba field. We found a possibility to control the spin precession with magnetic field.

• Quality Improvement in Health Care
• /
• v.3 no.1
• /
• pp.126-143
• /
• 1996

Background : Little work has been carried out regarding quality assessment research in a primary care setting, comparing with that of hospitals. This study aims to evaluate the process of diagnosis and management of hypertension by public health doctors on the basis of pre-established clinical guideline, and to identify several modifying factors associated with them. Methods : Hypertension was selected as the target disease, because it is a chronic disease which is of great public health importance. Self-administered questionnaires were mailed to public health doctors practicing at health centers and health subcenters across the nation. The response rate was 20.9%. The questionnaire included the diagnosis and management process such as measuring blood pressure, history taking, physical examinations, and treatment approches and potentially modifying factors such as level of training, duration of practice as a public health doctor, and education on management of hypertension. Results : Public health doctors pay little attention in measuring BP, hypertension related history taking, performing physical examination and laboratory examination. But they devoted much effort in diagnosing hypertension exactly and giving nonpharmacological treatment. Among various antihypertensive drugs, calcium-channel blockers were the most preferred agent(50.9%). Level of training, duration of practice ad a public health doctor, and education on management of hypertension made no difference on quality of care(p>0.05). Conclusion : These public health doctors showed poor compliance with the pre-established clinical guidelines, which leaves much to be desired in diagnosing and managing hypertensive patients by public health doctors. This study might be able to contribute to develop some strategies, such as educational programs, which would be able to improve the process of care in hypertensives.

• Journal of the Institute of Convergence Signal Processing
• /
• v.10 no.3
• /
• pp.181-185
• /
• 2009

Recently, much attention to a self-organizing mobile ad-hoc network is escalating along with progressive deployment of wireless networks in our everyday life. Being readily deployable, the MANET (mobile ad hoc network) can find its applications to emergency medical service, customized calling service, group-based communications, and military purposes. In this paper we investigate a time slot exchange problem found in the time slot based MAC, that is designed for IEEE 802.11b interfaces composing a MANET. The paper provides a method to maintain the quality of voice call by providing a new time slot when the channel assigned for that time slot gets noisy with interferences induced from other nodes, which belong to the same and/or other subgroups. In order to assess the performance of the proposed algorithm, a set of simulations using the OPNET modeler has been performed assuming that the IEEE 802.11b interfaces are operating under a modified MAC, which is a time slot based reservation MAC implemented in the PCF part of the superframe. In a real-time voice call service over a MANET of a size 500 ${\times}$ 500 meter squares with the number of nodes up to 100, the simulation results are collected and analyzed with respect to the packet loss rate and packet delay. The results show us that the proposed time slot exchange protocol improves the quality of voice call over that of plain DCF.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 2009.05a
• /
• pp.16.1-16.1
• /
• 2009

We have fabricated solution processed oxide semiconductor active layer for thin film transistors (TFTs). The oxide semiconductor layers were prepared by ink-jet printing the sol-gel precursor solution based on doped-ZnO. Inorganic ZnO-based thin films have drawn significant attention as an active channel layer for TFTs applications alternative to conventional Si-based materials and organic semiconducting materials, due to their wide energy band gap, optical transparency, high mobility, and better stability. However, in spite of such excellent device performances, the fabrication methods of ZnO related oxide active layer involve high cost vacuum processes such as sputtering and pulsed laser deposition. Herein we introduced the ink-jet printing technology to prepare the active layers of oxide semiconductor. Stable sol-gel precursor solutions were obtained by controlling the composition of precursor as well as solvents and stabilizers, and their influences on electrical performance of the transistors were demonstrated by measuring electrical parameters such as off-current, on-current, mobility, and threshold voltage. Microstructure and thermal behavior of the doped ZnO films were investigated by SEM, XRD, and TG/DTA. Furthermore, we studied the influence of the ink-jet printing conditions such as substrate temperature and surface treatment on the microstructure of the ink-jet printed active layers and electrical performance. The mobility value of the device with optimized condition was about 0.1-1.0 $cm^2/Vs$ and the on/off current ratio was about $10^6$. Our investigations demonstrate the feasibility of the ink-jet printed oxide TFTs toward successful application to cost-effective and mass-producible displays.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.36 no.3A
• /
• pp.205-214
• /
• 2011

In 3rd generation project partnership long term evolution, wireless multicast techniques which send the same data to multiple users under single frequency networks have attracted much attention. In the multicast system, the transmission mode needs to be selected for efficient data transfer while satisfying the multicast coverage requirement. To achieve this, users' channel state information (CSI) should be available at the transmitter. However, it requires too much uplink feedback resource if all the users are allowed to transmit their CSI at all the time. To solve this problem, in this paper, the multicast coverage prediction is suggested. In the proposed algorithm, each user measures its transition probabilities between the success and the fail state of the decoding. Then, it periodically transmits its CSI to the basestation. Using these feedbacks, the basestation can predict the multicast coverage. From the simulation results, we demonstrate that the proposed scheme can predict the multicast system coverage.

• Journal of Information Processing Systems
• /
• v.14 no.4
• /
• pp.1049-1061
• /
• 2018

As mobile devices such as smartphones and tablet PCs become more popular, users are becoming accustomed to consuming a massive amount of multimedia content every day without time or space limitations. From the industry, the need for user satisfaction investigation has consequently emerged. Conventional methods to investigate user satisfaction usually employ user feedback surveys or interviews, which are considered manual, subjective, and inefficient. Therefore, the authors focus on a more objective method of investigating users' brainwaves to measure how much they enjoy their content. Particularly for multimedia content, it is natural that users will be immersed in the played content if they are satisfied with it. In this paper, the authors propose a method of using a portable and dry electroencephalogram (EEG) sensor device to overcome the limitations of the existing conventional methods and to further advance existing EEG-based studies. The proposed method uses a portable EEG sensor device that has a small, dry (i.e., not wet or adhesive), and simple sensor using a single channel, because the authors assume mobile device environments where users consider the features of portability and usability to be important. This paper presents how to measure attention, gauge and compute a score of user's content immersion level after addressing some technical details related to adopting the portable EEG sensor device. Lastly, via an experiment, the authors verified a meaningful correlation between the computed scores and the actual user satisfaction scores.