• Journal of Korea Multimedia Society
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• v.18 no.2
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• pp.120-127
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• 2015

Mild Cognitive Impairment(MCI) is a prior step to Alzheimer's Disease(AD). It is different from AD which is seriously affecting daily life. Particularly, the hippocampus could be charged a crucial function for forming memory. MCI has a high risk about progress to AD. Our investigated research for a relationship between hippocampus and AD has been studied. The measurement of hippocampus volumetric is one of the most commonly used method. The three dimensional reconstructed medical images could be passible to interpret and its examination in various aspects but the cost of brain research with the medical equipment is very high. In this study, 3D visualization was performed from a series of brain Magnetic Resonance Images(MRI) and we have designed and implemented a competitive software tool based on the open libraries of Visualization ToolKit(VTK). Consequently, our visualization software tool could be useful to various medical fields and specially prognosis and diagnosis for MCI patients.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.866-871
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• 2006

This paper presents the design of a reservation-based MAC protocol to support multimedia traffic over mobile ad-hoc networks and evaluates its performance. Our MAC protocol is based on a hierarchical approach consisting of two sub-layers. The lower sub-layer of the MAC protocol with reservation provides a fundamental access method using CSMA/CA in order to support asynchronous data traffic over mobile ad-hoc networks. The upper sub-layer supports real-time periodic data by making a slot reservation before transmitting actual data. The proposed protocol has been validated through simulations using ns-2. The results show that the proposed MAC protocol can offer higher throughput and lower delay than standard implementations of the IEEE 802.11.

• Journal of Korea Society of Industrial Information Systems
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• v.16 no.2
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• pp.13-18
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• 2011

Security supports are a significant factor in mobile ad hoc networks. Especially in dynamic topologies, considering cluster, key management is essential to provide a secure system. Recently, Li-Liu proposed iD-based multiple key management scheme for cluster-based ad hoc networks. However, we found the security weakness of their scheme. In this paper, we analyze the security of Li-Liu's scheme and show that master secret key and fragment of the master secret key can be revealed to compromised CHs and nodes. Furthermore, we propose a solution to improve the scheme against disclosure of the share key and the master secret key even though system parameters are opened to compromised nodes and modify the Li-Liu's scheme fitted for a scalable networks. The improved IMKM scheme could be usefully applied in dynamic cluster-based MANETs such as the military battlefields, mobile marketplace and VANETs.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.11 no.4
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• pp.239-243
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• 2011

In wireless ad-hoc network, the detection of link breakage and re-establishing the route path causes lots of network overhead and results in communication delay. In the LBN method, the node causing a link breakage actively sends a message to neighbors so that they can instantly start re-establishing process of new path. In this paper we describe the result of network simulation we performed using NS2 to show the effectiveness of LBN method.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.36 no.7A
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• pp.662-668
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• 2011

This paper analyzes the performance of the Ad hoc On-demand Distance Vector (AODV) routing protocol and Optimized Link State Routing (OLSR) for Mobile Ad hoc Networks (MANETs) using node mobility models. Mobility affects the performance of a routing protocol as it causes changes to network topology. Thus, evaluating the performance of a MANET routing protocol requires mobility models that can accurately represent the movements of mobile nodes. Therefore, this paper evaluates the performance of the AODV and OLSR routing protocols using the random way point model and the Levy walk model by the ns-2 simulations.

• Journal of Communications and Networks
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• v.13 no.5
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• pp.525-535
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• 2011

In this paper, we study the contribution of network coding (NC) in improving the multicast capacity of random wireless ad hoc networks when nodes are endowed with multi-packet transmission (MPT) and multi-packet reception (MPR) capabilities. We show that a per session throughput capacity of ${\Theta}$(nT$^3$(n)) can be achieved as a tight bound when each session contains a constant number of sinks where n is the total number of nodes and T(n) is the transmission range. Surprisingly, an identical order capacity can be achieved when nodes have only MPR and MPT capabilities. This result proves that NC does not contribute to the order capacity of multicast traffic in wireless ad hoc networks when MPR and MPT are used in the network. The result is in sharp contrast to the general belief (conjecture) that NC improves the order capacity of multicast. Furthermore, if the communication range is selected to guarantee the connectivity in the network, i.e., ${\Omega}$($\sqrt{log\;n/n}$)=T(n) = O(log log n / log n), then the combination of MPR and MPT achieves a throughput capacity of ${\Theta}$(log$^{\frac{3}{2}}$ n/$\sqrt{n}$) which provides an order capacity gain of ${\Theta}$(log$^2$ n) compared to the point-to-point multicast capacity with the same number of destinations.

• Membrane and Water Treatment
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• v.10 no.3
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• pp.213-221
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• 2019

Anaerobic digestion (AD) has been widely used to valorize food waste (FW) because of its ability to convert organic carbon into $CH_4$ and $CO_2$. Korean FW has a high content of fruits and vegetables, and efficient hydrolysis of less biodegradable fibers is critical for its complete stabilization by AD. This study examined the digestates from different anaerobic digesters, namely Rs, Rr, and Rm, as the inocula for the AD of vegetable waste (VW) and cellulose (CL): Rs inoculated with anaerobic sludge from an AD plant, Rr inoculated with rumen fluid, and Rm inoculated with anaerobic sludge and augmented with rumen fluid. A total of six conditions ($3\;inocula{\times}2\;substrates$) were tested in serial subcultures. Biogas yield was higher in the runs inoculated with Rm than in the other runs for both VW (up to 1.10 L/g VS added) and CL (up to 1.05 L/g VS added), and so was biogas production rate. The inocula had different microbial community structures, and both substrate type and inoculum source had a significant effect on the formation and development of microbial community structures in the subcultures. The overall results suggest that the bioaugmentation with rumen microbial consortium has good potential to enhance the anaerobic biodegradability of VW, and thereby can help more efficiently digest high fiber-content Korean FW.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.11 no.1
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• pp.91-99
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• 2000

Objectives：Present study developed the computerized ADHD Diagnostic System(ADS) in order to diagnose ADHD and evaluate treatment effect of it, and conducted a standardization study for ADS. Methods：The normative group was composed of 847 children and adolescents between the age of 5 and 15(boy 429, girl 418) living in the areas of Seoul, Kyunggi-do, and Kangwon-do. 30 ADHD children with age ranged 7 to 9 years were participated present study to evaluate the validity of ADS. To establish the norms for diagnosing ADHD, the means and standard deviations of normative group were used to calculate T-scores for each age group. Results：The reliability coefficient of ADS(Cronbach's ${\alpha}$) was .85. There were significant differences in the measures of ADS except commission error between the normal and the ADHD groups. Three factors were extracted through factor analysis of ADS, which were labelled 'inattention', 'slow information processing' and 'impulsivity'. Discriminant analysis showed that ADS significantly discriminate the normal and the ADHD groups. Percentage of correct classification by ADS variables was 96.7%. Conclusion：These results put together strongly support the reliability and validity of ADS as a diagnostic instrument for ADHD.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.4
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• pp.201-209
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• 2016

Theoretical maximum methane yield of glucose at STP (1 atm, $0^{\circ}C$) is 0.35 L $CH_4/g$ COD. However, most researched actual methane yields of anaerobic digester (AD) on lab scale is lower than theoretical ones. A wide range of them have been reported according to experiments methods and types of organic matters. Recent year, a MET (Microbial electrochemical technology) is a promising technology for producing sustainable bio energies from AD via rapid degradation of high concentration organic wastes, VFAs (Volatile Fatty Acids), toxic materials and non-degradable organic matters with electrochemical reactions. In this study, methane yields of food waste leachate and sewage waste sludge were evaluated by using BMP (Biochemical Methane Potential) and continuous AD tests. As the results, methane production volume from the anaerobic digester equipped with MET (AD + MET) was higher than conventional AD in the ratio of 2 to 3 times. The actual methane yields from all experiments were lower than those of theoretical value of glucose. The methane yield, however, from the AD + MET occurred similar to the theoretical one. Moreover, biogas compositions of AD and AD + MET were similar. Consequently, methane production from anaerobic digester with MET increased from the result of higher organic removal efficiency, while, further researches should be required for investigating methane production mechanisms in the anaerobic digester with MET.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.27 no.2
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• pp.103-109
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• 2005

In spite of the ongoing advances, standard therapies for oral cancer still has some limitations in efficacy and in ability to prolong survival rate of advanced disease and result in significant functional defect and severe cosmetic deformity. Currently gene therapy using tumor suppressor gene is considered as a potent candidate for new therapeutic approaches that can improve efficacy and reduce complications. The purpose of this research is to identify the role of adenoviral vector to transfer HCCS-1 tumor suppressor gene in oral cancer cells and to find out whether there is a possibility for it to serve in the field of gene therapy. The human SCC-25 cell line was used for transfection. To determine the efficiency of the adenovirus as a gene delivery vector cell line was transduced with LacZ gene and analysed with X-gal staining. Northern blot was performed to confirm the tranfection with HSCC-1 gene and cell viability was assessed by cell cytotoxicity assay. We had successfully construct the recombinant HSCC-1 adenovirus(Ad5CMV-HCCS-1). DNA extracted from Ad5CMV-HCCS-1 revealed HCCS-1 gene is incorporated. The transduction efficiencies were over than 50% of SCC-25 cells with a MOI of 2 and over 95% with a MOI of 50. Northern blot analysis showed that a single 0.6kb mRNA transcript was expressed in Ad5CMV-HCCS-1 transduced SCC-25 cells. There was no or very low transcription HCCS-1 mRNA in wild and Ad5CMV-LacZ transduced SCC-25 cells. Cells transduced with Ad5CMV-HCCS-1 showed significant growth inhibition. By day 6, Ad5CMV-HCCS-1 treated cell count was decreased to 30% of mock-infected cells, while that of Ad5CMV-LacZ treated cells was 90% of mock-infected cells (p<0.05). Finally, these result suggest that the Ad5CMV-HCCS-1 has potential as a gene therapy tool for oral cancer.