• Journal of KIISE:Computing Practices and Letters
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• v.14 no.8
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• pp.773-777
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• 2008

Today's mobile devices have characteristic of random mobility in the heterogeneous networks. Thus they should have various kinds of security requirements. To satisfy these requirements, there are many researches on security and authentication for mobile devices. TCG(Trusted Computing Group) designed TPM(Trusted Platform Module) for providing privacy and authentication to users. Also TCG suggest a protocol, called DAA(Direct Anonymous Attestation) which uses zero knowledge proof theory. In this paper, we will implement DAA protocol using Java and show the efficiency and the problems in the DAA protocol. Finally, we will suggest an efficient mobile DAA model through Java test module for the DAA protocol.

• ETRI Journal
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• v.32 no.1
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• pp.44-52
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• 2010

Ultra-wideband (UWB) systems have witnessed a debate over whether they may cause interference to other existing and future narrowband systems sharing their band of operation. The detect and avoid (DAA) mechanism was developed as a solution to reduce interference to narrowband systems in order to ease regulatory concerns. It works by adaptively reducing the transmitted power at the overlapping bands upon detecting an active narrowband link. However, employing DAA degrades the performance of UWB transmissions. In this paper, we present the Korean UWB regulations as an example of regulations that require DAA in certain bands. We investigate DAA's impact on performance and propose a method to mitigate it, which provides UWB with the more efficient support of the DAA mechanism and enables it to avoid a larger number of narrowband users while sustaining the data rate. Results show significant improvement in performance with the application of our technique compared to conventional performance.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.4
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• pp.241-255
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• 2015

Recent network environment has been rapidly evolved to cloud computing environment based on the development of the Internet technologies. Furthermore there is an increasing demand on mobile cloud computing due to explosive growth of smart devices and wide deployment of LTE-based cellular networks. Thus mobile Desktop-as-a-Service(DaaS) could be a pervasive service for nomadic users. In addition, video streaming traffic is currently more than two-thirds of mobile traffic and ever increasing. All such trends enable that video streaming in mobile DaaS could be an important concern for mobile cloud computing. It should be noted that the performance of the Transmission Control Protocol(TCP) on cloud host servers greatly affects Quality of Service(QoS) of video streams for mobile users. With widely deployed Linux server platforms for cloud computing, in this paper, we conduct an experimental analysis of the twelve Linux TCP variants in mobile DaaS environments. The results of our experiments show that the TCP Illinois outperforms the other TCP variants in terms of wide range of packet loss rate and propagation delay over LTE-based wireless links between cloud servers and mobile devices, even though TCP CUBIC is usually used in default in the current Linux systems.

• Journal of Animal Science and Technology
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• v.46 no.1
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• pp.91-96
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• 2004

It is generally believed that amino acids occurring naturally in mammals are of the L-configuration. D-amino acid(DM) are common in nature as constituents of bacterial cell walls and several antibiotics. Recent reports have demonstrated the presence of small amounts of free DM in milk. The presence of free DM may affect the food quality by decreasing the nutritional value. Our objective was to examine whether the free DM carne from psychrotrophic bacteria. Free DM was produced by treating raw milk with Pseudomonas spp. The samples were extracted with sulphosalicylic acid and derivatized with AccQ-$Tag^{TM}$ reagent when the analysis was carried out by reverse-phase HPLC. We tested correlations of the content of free DM with bacterial growth. Significant amounts of free D-a1anine and D-proline have been found in the raw milk inoculated with Pseudomonas spp. The increase of D-alanine and D-proline appeared to be mainly related to the presence of Pseudomonas fluorescens. These results suggest that free DM may be considered as an indicator of psychrotrophic bacterial milk contamination.

• Journal of KIISE:Computing Practices and Letters
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• v.16 no.8
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• pp.878-882
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• 2010

DaaS model that surrogates their data has a problem of privacy leakage by service provider. In this paper, we analyze inference attack that can occur on encrypted data that consist of multiple column through index, and we suggest b-anonymity to protect data against inference attack. We use R+-tree technique to minimize false-positive that can happen when we use an index for efficiency of data processing.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.3
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• pp.482-488
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• 2012

Desktop is offered to each individual in Educational environments of school or academy, as the users are increasing, the more Desktop is required for each person. Huge Desktop accession resulted in many problems including difficulty of management, Software and Hardware cost rising, cramped places, power consumption increasing and etc. To solve those problems, we focus into uprising technology solution, such as Multi Computer, Desktop Virtualization, and DaaS(Desktop as a Service). In this paper, existing problems that can dramatically improve the private cloud computing for desktop virtualization with the requirements of the system were analyzed.

• TTA Journal
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• s.139
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• pp.48-53
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• 2012

• Journal of Food Hygiene and Safety
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• v.37 no.4
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• pp.216-224
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• 2022

This study was aimed at validating the analysis methods for deacetylasperulosidic acid (DAA), total sugar, galacturonic acid, glucose, and galactose, which are the indicator components of fermented Morinda citrifolia polysaccharide extract (Vitalbos). We modified the previously reported methods for validating the analytical methods. The specificity, linearity, precision, accuracy, limit of detection (LOD), and limit of quantification (LOQ) were measured using phenol-sulfuric acid method and high-performance liquid chromatography (HPLC). The retention time and spectrum of the standard solution of Vitalbos coincided, confirming the specificity. The calibration curve correlation coefficient (R²), of five indicator components, ranged from 0.9995-0.9998, indicating excellent linearity of 0.99 or more. The intra-day and inter-day precision range of the assay was 0.14-3.01%, indicating a precision of less than 5%. The recovery rate was in the range of 95.13-105.59%, presenting excellent accuracy. The LOD ranged from 0.39 to 0.84 ㎍/mL and the LOQ ranged from 1.18 to 2.55 ㎍/mL. Therefore, the analytical method was validated for DAA, total sugar, galacturonic acid, glucose, and galactose, in Vitalbos. The indicator component content in Vitalbos was determined using a validated method. The contents of DAA, total sugar, galacturonic acid, glucose, and galactose were 2.31±0.06, 475.92±5.95, 72.83±1.05, 71.63±2.44, and 67.30±2.31 mg/g of dry weight, respectively. These results suggest that the developed analytical method is efficient and could contribute to the quality control of Vitalbos, as a healthy functional food material.

• Proceedings of the IEEK Conference
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• 2004.08c
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• pp.528-531
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• 2004

This paper presents the design and implementation of a QoS based IrDA in mobile phones. The IrDA standards have arised from the need to connect various mobile devices together. But currently, we have a difficult to connecting various mobile devices together. The difficult thing is to adjust the minimum turn around time. The minimum turn around time in IrDA deals with the time needed for a receiver circuit to recover following saturation by transmissions from the same device (turn around latency). This parameter corresponds to the required time delay between the last byte of the last frames sent by a station and the point at which it is ready the first byte of a frame from another station. This parameter comes into play when the link is turned around and is negotiated independency for each station. We solve this matter by using the Dynamic Adjustment Algorithm (DAA). The dynamic adjustment algorithm adjusts the minimum turn around time according to the numbers of devices. We apply our direct adjustment algorithm to our QoS based IrDA in mobile phones and show the improved performance of connection with various mobile phones together.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.17 no.10
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• pp.1164-1174
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• 1992

In this paper, an Information Security protocol in LLC/MAC Layer Architecture is discussed. This paper examines the security Vulnerability and threats, the security Service required to protect these threats, and architectural considerations of security protocol in IEEE 802 LAN architecture. To provide an Information security service, an information security protocol(SP2 : Security Protocol 2) PDU construction with LLC/MAC service primitives is suggested. To construct the SP2 protocol, the ECB, CBC mode of DES algorithm and DAA(Data Authentication Algorithm) of FIPS is used. The SP2 protocol suggested in this paper provides data origin authentication, data confidentiality, data integrity service.