• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11A
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• pp.1128-1137
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• 2007

Recently, according to being advanced internet, mobile communication technique, Telematics environment which users in vehicle can use internet service in LAN(Local Area Network) via mobile device has being realized. In this paper, we propose the remote user authentication protocol to solve these issues. Additionally, we use biometrics(fingerprint) for our user authentication protocol cause it can provide to avoid critical weakness that can be lost, stolen, or forgotten and to make authentication easily. In our user authentication protocol, to protect the biometric we use session key which is generated from master key distributed in our key distribution protocol. In particular, we propose secure protocol between APs considering weakness of security in mobile environment. Based on implementation of our proposed protocol, we conform that our proposed protocols are secure from various attack methods and provide real-time authentication.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.42 no.2
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• pp.403-412
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• 2017

With the introduction of BIM and ICT technology, 'Cloud-based collaborative design support system' has been actively researched and new user interface is needed to support it. When developing the user interface, scenario - based design method is selected which based on the actual usage scenarios to anticipate the usage situation and reflect the user's requirements. However, since the existing scenario-based design technique is an inductive method, it is difficult to cover the usage situation of all users when creating the usage scenario. For this reason, there is a need for a new scenario creation method that can systematically create and modify scenarios instead of inductive methods. This study proposes a 'Multi-scenario-based design method' that complemented the existing method and verify its usability by applying it to the user interface development process of 'Cloud-based collaborative design support system'.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.5
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• pp.31-40
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• 2010

This paper describes a LDPC decoder for IEEE 802.11n wireless LAN standard. The designed processor supports parity check matrix for block length of 1,944 and code rate of 1/2 in IEEE 802.11n standard. To reduce hardware complexity, the min-sum algorithm and layered decoding architecture are adopted. A novel memory reduction technique suitable for min-sum algorithm was devised, and our design reduces memory size to 25% of conventional method. The LDPC decoder processor synthesized with a $0.35-{\mu}m$ CMOS cell library has 200,400 gates and memory of 19,400 bits, and the estimated throughput is about 135 Mbps at 80 MHz@2.5v. The designed processor is verified by FPGA implementation and BER evaluation to validate the usefulness as a LDPC decoder.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.122-128
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• 2016

The Biosensor biosensor pattern was developed by via an EHD (electro-hydro-dynamics (EHD) patterning process that was performed under atmospheric pressure at room temperature in a single step. The drop diameter was smaller than nozzle diameter and applied high viscosity conductive ink was applied in the EHD patterning method to provide a clear advantage over the piezo and thermal inkjet printing techniques. The Biosensor's biosensor's micro electrode pattern was printed by via a continuous EHD patterning method using 3three- type types of control parameters parameter (input voltage, patterning speed, nozzle pressure). High viscosity (1000 cps) conductive ink with 75 wt% of silver nanoparticles was used for experimentation. The incremental result of impedance of biosensor impedance was measured between the antibody ($10ug{\mu}g/ml$) to spore (0.1 ng/ml, 10 ng/ml, and $1ug{\mu}g./ml$) reaction at frequency 493 MHz frequency.

• The Journal of the Korea Contents Association
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• v.11 no.1
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• pp.26-33
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• 2011

In ubiquitous environments that numerous mobile objects exist, the location-based services have risen as an important application field. For efficient location-based services, various techniques with broadcast schemes have been studied. However, they were mainly concerned with the implementation of a broadcast index and did not consider techniques for reducing the size of the entire broadcast data. Therefore, this paper proposes a data distribution broadcast scheme based on sensor networks that considers the mobile patterns of an object in road network environments. In this paper we also propose a road network based sensor clustering technique for the efficiency of the proposed distributed broadcast scheme. In order to show the superiority of the proposed scheme, we compare it with the existing broadcast scheme in various environments.

• The Journal of the Korea Contents Association
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• v.10 no.2
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• pp.130-137
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• 2010

Light Drawing is a photographic technique which exposures are made at night or in a darkened room usually by moving a hand-held light source[1]. Due to the limitations of equipment and environment, users having difficulty in drawing a picture in 3D space. If user take a light drawing, they need a camera that have function and darkened environment. Alternative solution is that we can make a light drawing picture by using the computer drawing tool as in Photoshop. Nevertheless, this solution will let the User lose their interest in drawing because this solution cannot synchronize between the real action of human hand motion and the electronic input devices such as mouse and keyboard. This paper proposed a digital content that can make light drawing easier. We used a digital content that will facility Light Drawing easier. We can measure the light spot position by using the stereo camera. Based on the measured position of the light spot, we reproduce light drawing in virtual space by using drawing effect method.

• The Journal of Korean Physical Therapy
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• v.25 no.2
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• pp.76-80
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• 2013

Purpose: The objective of this study was to offer primary clinical data examining whether change of imaging structure and quantitative evaluation of muscle activity on myofascial trigger points can lead to implementation of an analytical technique for evaluation of myofascial pain diagnoses. In addition, we examined the effect of a variety of mediation techniques, in order to examine neuromuscular physiological characteristics of myofascial trigger points muscle by comparing differences in pressure pain threshold and ultrasound imaging. Methods: Participants in the study included 30 adults in their twenties. The subjects were divided into the normal and myofascial trigger points groups. Clinical outcomes were evaluated by pressure pain threshold for pain and ultrasound imaging was performed for evaluation of the structural characteristics of muscle. Independent t-test was used for statistical analysis. Results: The two groups showed statistical significance in the change in pressure pain threshold (p<0.05). Findings of ultrasound imaging analysis showed no significant differences, increased muscle thickness was observed (p>0.05). Findings of ultrasound imaging analysis showed significant differences, increased muscle echodensity was observed (p<0.05). Findings on ultrasound imaging analysis showed significant differences, increased muscle white area index was observed (p<0.05). Conclusion: From these results, active myofascial trigger points muscle showed quality deterioration on ultrasound imaging. Thorough evaluation of imaging structure and physiological characteristics can be useful quantitative analytical techniques for diagnosis of myofascial pain syndrome and a primary factor reflected in physical therapy intervention.

• Journal of the Korean Society for Nondestructive Testing
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• v.28 no.2
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• pp.101-111
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• 2008

Strain imaging in a medical ultrasound imaging system can differentiate the cancer or tumor in a lesion that is stiffer than the surrounding tissue. In this paper, a strain imaging technique using quasistatic compression is implemented that estimates the displacement between pre- and postcompression ultrasound echoes and obtains strain by differentiating it in the spatial direction. Displacements are computed from the phase difference of complex baseband signals obtained using their autocorrelation, and errors associated with converting the phase difference into time or distance are compensated for by taking into the center frequency variation. Also, to reduce the effect of operator's hand motion, the displacements of all scanlines are normalized with the result that satisfactory strain image quality has been obtained. These techniques have been incorporated into implementing a medical ultrasound strain imaging system that operates in real time.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.75-94
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• 2009

Since XML emerged as a standard for data exchange on the web, it has been established as a core component in e-Commerce and efficient query processing over XML data in ubiquitous computing environment has been also receiving much attention. Recently, the techniques were proposed whereby an XML document is fragmented into XML fragments to be streamed and the mobile clients receive the stream while processing queries over it. In processing queries over an XML fragment stream, the average access time significantly depends on the order of fragments in the stream. As such, for query performance, an efficient organization of XML fragment stream is required as well as the indexing for energy-efficient query processing due to the reduction of tuning time. In this paper, a technique of XML fragment stream organization based on query frequencies, fragment size, fragment access frequencies, and an active XML-based indexing scheme are proposed. Through implementation and performance experiments, our techniques were shown to be efficient compared with the conventional XML fragment stream organizations.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.5
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• pp.1-9
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• 2012

In this paper, we presents the modeling and implementation of the DDS(Direct Digital synthesizer) driven offset PLL(Pghase Locked Loop) with DAC(Digital Analog Converter) for coarse tune. The PLL synthesizer was designed for minimizing the size and offset frequency and DDS technique was used for ultra low noise and fast lock up time, also DAC was used for coarse tune. The output phase noise was analyzed by superposition theory with the phase noise transfer function and noise source modeling. the phase noise prediction was evaluated by comparing with the measured data. The designed synthesizer has ultra fast lock time within 6 usec and ultra low phase noise performance of -120 dBc/Hz at 10KHz offset frequency.