• Journal of the Microelectronics and Packaging Society
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• v.12 no.3 s.36
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• pp.267-274
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• 2005

This paper presents the fabrication of surface acoustic wave (SAW)-based pressure sensor for long-term stable mechanical compression force measurement. SAW pressure sensor has many attractive features for practical pressure measurement: no battery requirement, wireless pressure detection especially at hazardous environments, and easy other functionality integrations such as temperature, humidity, and RFID. A $41^{\circ}$ YX $LiNbO_3$ piezoelectric substrate was used because of its high SAW propagation velocity and large values of electromechanical coupling factors $K^2$. A silicon substrate with $\~200{\mu}m$ deep cavity was bonded to the diaphragm with epoxy, in which gold was covered all over the inner cavity in order to confine electromagnetic energy inside the sensor, and provide good isolation of the device from its environment. The reflection coefficient $S_{11}$ was measured using network analyzer. High S/N ratio, sharp reflected peaks, and clear separation between the peaks were observed. As a mechanical compression force was applied to the diaphragm from top with extremely sharp object, the diaphragm was bended, resulting in the phase shifts of the reflected peaks. The phase shifts were modulated depending on the amount of applied mechanical compression force. The measured $S_{11}$ results showed a good agreement with simulated results obtained from equivalent admittance circuit modeling.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.1
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• pp.209-218
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• 2017

Healthcare services can be provided through a number of independent service platforms for measurement of vital signs, diagnosis and prevention of diseases, and Information and communication technology(ICT) such as internet and mobile are converged to provide health information to users at anytime and anywhere, and it is in the center of the IoT(Internet of things). Accordingly, in this paper, we designed IoT based urination management system and evaluate the performance. A low - power Zigbee network was constructed for the configuration of the urination management system. The implemented capacitive diaper sensor was operable for the duration of 2,000 hours. We also built a database server using Raspberry Pi, a tiny embedded device, and stored the collected data to verify the data through an Android-based mobile application. The proposed urination management system can be utilized not only for the older patients, but also for the infants.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.811-823
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• 2011

This paper proposes an efficient transmission method for the panoramic multimedia contents. The panoramic video provides wide sight and various view-point to the user. The traditional methods of the panoramic multimedia content transmission has several limitations, as follow; A client suffers a long initial delay time to play a panoramic video when it is transmitted through a limited bandwidth network, because the panoramic video has larger data size than a general video. And if a client's display device has limited resolution, such as mobile phone, laptop PC monitor, etc. it can not display the entire panoramic video that has a wide view video sequence. So, in order to overcome the obstacles, this paper proposes an efficient transmission of panoramic multimedia contents. This method will increase the transmission efficiency throughout the technique of the scene description in MPEG-4 system. Also we demonstrated the efficiency of the proposed method by comparison with existing methods.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.45 no.7
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• pp.610-617
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• 2017

In the recent weapon system trend, it is required to develop small and low cost guidance missile to track and strike the enemy target effectively. Controling the such small drone typed weapon demands a integrated electronic device that equipped with not only a wireless network interface, a high resolution camera, various sensors for target tracking, and position and attitude control but also a high performance processor that integrates and processes those sensor outputs in real-time. In this paper, we propose the android smartphone as a solution for that and implement the guidance and control application of the missile. Furthermore, the performance of the implemented guidance and control application is analyzed through the simulation.

• Journal of Broadcast Engineering
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• v.16 no.5
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• pp.738-749
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• 2011

In this paper, we study QoS(Quality of Service) control protocols and the effect using MAC/PHY parameters of client device in mobile network. We proposes the way of controling the bit-rate by estimating the channel condition of the client with measured MAC/PHY parameters which is sent from the client. With the proposed method, more accurate available bit-rate can be estimated compared to conventional protocol, RTCP(Real-time Transport Control Protocol). The accurate bit-rate estimation can decrease wasted bit-rate and transport delay. In the result of the advantages, the transported video quality can be enhanced. In this paper, we show the effects of enhancement using client's the field data measured in WiMAX.

• The Research Journal of the Costume Culture
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• v.23 no.6
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• pp.1097-1115
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• 2015

ICT in the IOT era is the core basis of modern society. This study investigated and analyzed the recent commercialization trends of smart fashion products internationally and domestically, to utilize them as the basis of data for developing user-friendly smart fashion products that can meet the needs of consumers. Keyword research using the most representative search engines, Google and Naver was conducted for searching for various wearable items commercialized actively since 2010. The final 78 products were classified by the physical area, and the key features and benefits were analyzed. Smart fashion products were classified as four physical types for the head and face, torso, arms and hands, and ankles and feet. Smart fashion products for each body part were developed in various ways, such as hats, glasses, lenses, virtual screens, earphones, headsets, clothing, watches, wrist bands, gloves, rings, wallets, bags, anklets, shoes, socks, and insoles. The main features were music playback, bluetooth, a camera based on NFC, virtual effects, health and safety protection through measuring heartbeat and momentum, and social network sharing of all kinds of information, based on inter-working with a smartphone. These functions represent the physical, social, and emotional interactions among users and their surroundings, as well as the users, themselves. The research results are expected to be used in future studies on planning user-friendly and marketable products through in-depth analysis of the design characteristics of smart fashion products as well as consumer responses.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.7-12
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• 2014

The data forwarding transmission is an important function of the relay in cooperative communication in wireless communication systems. However, additional relay cause the waste of power consumption and cost. Therefore, in this paper, we consider how to use the user mobile devices in stead of relays to deal with this problem. In this paper, we proposed the protocol that divide each relay into two states of idle and non-idle. The receiver has two functions of base station and user mobile device. In this case, it is possible that no additional cost, and improve the spectral efficiency and network capacity. We verified BER performance for the proposed protocol over Rayleigh fading through Monte-Carlo simulation.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.11
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• pp.1-12
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• 2005

In wireless personal area networks(PANs), the successful design of channel time allocation algorithm is a key factor in guaranteeing the various quality of service(QoS) requirements for the stringent real-time constraints of multimedia services. In this paper we propose a dynamic channel time allocation algerian for providing delay guarantees to multimedia traffics such as MPEG streams in the IEEE 802.15.3 high-rate WPANs. The dynamic algorithm exploits the characteristics of MPEG stream, wherein the devices (DEVs) send their channel time requests only at the end of superframe boundaries. The algerian uses mini packets for feedback control in order to deliver dynamic parameters for channel time requests from the DEVs to the piconet coordinator (PNC). In this scheme, the duration of channel time allocated to a DEV during a superframe is changed dynamically depending on the MPEG frame type, traffic load and delay bound of the frame, etc. Performance of the proposed scheme is investigated by simulation. Our results show that compared to traditional scheme, the proposed scheme is very effective and has high performance while guaranteeing the delay bound.

• Journal of Digital Convergence
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• v.13 no.4
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• pp.51-59
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• 2015

In this study, we derived key factors required for the activation of the domestic e-book market and evaluated its importance. Specifically, we derived key evaluation items of C-P-N-D ecosystem perspective through literature review. In addition, we analyzed the implications by evaluating the importance depending on AHP after derived items were modified and classified together with the publisher working group. As the results of analysis, experts considered price(0.785), quality(0.149) and service(0.066) as the important items among three items derived as the primary upper class. A total of 23 factors were derived as the secondary lower class. The importance depending on C-P-N-D areas is as follows: contents(0.43), platform(0.35), device(0.11) and network(0.05). Among the entire sub-factors, three items such as 'distribution of profits with platform', 'profitability of product costs of contents' and 'appropriate rental price of contents and streaming service' showed significantly higher importance than that of other 20 items.

• Journal of the Korea Society of Computer and Information
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• v.19 no.1
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• pp.65-76
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• 2014

In this paper, we propose a high-level programming language for packet processing called eFlowC and it supporting programming development environment. Based on the C language which is already familiar and easy to use to program developers, eFlowC maintains the similar syntax and semantics of C. Some features that are unnecessary for the packet processing has been removed from C, eFlowC is highly focused on performing packet data, database, string byte information checking and event processing. Design high-level programming languages and apply an existing language or compiler technology, language function and compilation process that is required for packet processing will be described. In order to use the DPIC device such as X11, we designed a virtual machine eFVM that takes into account the scalability and portability. We have evaluated the utility of the proposed language by experimenting a variety of real application programs with our programming environment such as compiler, simulator and debugger for eFVM. As there is little research that devoted to define the formats, meanings and functions of the packet processing language, this research is significant and expected to be a basis for the packet processing language.