• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.4B
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• pp.566-575
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• 2010

In recent, artificial immune system has become an important research direction in the anomaly detection of networks. The conventional artificial immune systems are usually based on the negative selection that is one of the computational models of self/nonself discrimination. A main problem with self and non-self discrimination is the determination of the frontier between self and non-self. It causes false positive and false negative which are wrong detections. Therefore, additional functions are needed in order to detect potential anomaly while identifying abnormal behavior from analogous symptoms. In this paper, we design novel network attack detection and response schemes based on artificial immune system, and evaluate the performance of the proposed schemes. We firstly generate detector set and design detection and response modules through adopting the interaction between dendritic cells and T-cells. With the sequence of buffer occupancy, a set of detectors is generated by negative selection. The detection module detects the network anomaly with a set of detectors and generates alarm signal to the response module. In order to reduce wrong detections, we also utilize the fuzzy number theory that infers the degree of threat. The degree of threat is calculated by monitoring the number of alarm signals and the intensity of alarm occurrence. The response module sends the control signal to attackers to limit the attack traffic.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.3
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• pp.47-61
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• 2014

Many angel investors hesitate to invest in early-stage company. Most early-stage company has no sales and only R&D step project or in early approach of market. So it's impossible to evaluate early-stage company quantitatively. Therefore many angel investors depend on CEO's tendency to evaluate company and make decision for investment. The purpose of this study is discover the entrepreneurial characteristics of CEO and the importance level which affect on the angel investors decision making factors for investment. To identify the factors of entrepreneurial characteristics, survey was conducted by Delphi Technique which is involved by 20 experts who is angel investment club members, venture capitalists, CEOs and officers. Three rounds of survey results derived 10 elements of entrepreneurial characteristics for investment decision making factors including reliability, risk sensitivity, passion, perseverance, integrity, leadership, startup experience, organizational management skills, innovation and social networking. In addition, this study derived the importance level of elements of entrepreneurial characteristics based on the AHP(Analytic Hierarchy Process) theory and maintained the logical consistency by pair-wise comparison for each element. As a result of analyzing the importance of entrepreneurial characteristics, the sequence is reliability (18.1%), integrity (15.9%), leadership (11.7%), organizational management skills (10.0%), social networking (9.5%), passion(9.1%), perseverance(8.4%), innovation(8.1%), startup experience(5.3%) and risk sensitivity(3.9%) respectively. The significance of this study is somewhat decrease limit of the uncertainty arising from angel investors and angel investors can help a decision making, by discover factors of entrepreneurial characteristics that can be called the biggest influencing factors among Investor's investment decision-making In early stage companies and compare importance.

• Research in Plant Disease
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• v.21 no.2
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• pp.74-81
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• 2015

The specific and sensitive nested-PCR method to detect Acidovorax citrulli, a causal agent of bacterial fruit blotch on cucurbitaceae, was developed. PCR primers were designed from the draft genome sequence which was obtained with the Next Generation Sequencing of A. citrulli KACC10651, and the nested-PCR primer set (Ac-ORF 21F/Ac-ORF 21R) were selected by checking of specificity to A. citrulli with PCR assays. The selected nested-PCR primer amplified the 140 bp DNA only from A. citrulli strains, and detection sensitivity of the nested PCR increased 10,000 times of $1^{st}$ PCR detection limit (10 ng genomic DNA/PCR). The nested PCR detected A. citrulli from the all samples of seed surface wash (external seed detection) of the artificially inoculated watermelon seeds with $10^1cfu/ml$ and above population of A. citrulli while the nested PCR could not detected A. citrulli from the mashed seed suspension (internal seed detection) of the all artificially inoculated watermelon seeds. When the naturally infested watermelon seeds (10% seed infested rate with grow-out test) used, the nested PCR detected A. citrulli from 2 seed samples out of 10 replication samples externally and 5 seed samples out of 10 replication samples internally. We believe that the nested-PCR developed in this study will be useful method to detect A. citrulli from the Cucurbitaceae seeds.

• The Korean Journal of Mycology
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• v.45 no.4
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• pp.386-393
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• 2017

Onion downy mildew, caused by Peronospora destructor, is a major disease in onion cultivation areas in Korea. The causal fungi were collected and analyzed based on sequence similarity and molecular phylogenetic relationships of multi-gene sequences, including the internal transcribed spacer (ITS) region. All isolates from Changnyeong-gun, Hamyang-gun, and Hapcheon-gun in Gyeongnam province, and Muan-gun, Haenam-gun, and Sinan-gun in Jeonnam province were identical in the four types of gene sequences, indicating they were genetically the same strains. In this study, a PCR method was developed based on the ITS gene sequences to amplify the specific DNA fragment for P. destructor only. The detection limit of was total genomic DNA of the P. destructor and the plant $0.7ng/{\mu}L$. Therefore, the developed PCR method could be used to detect P. destructor effectively from symptomless onion leaves.

• Investigative Magnetic Resonance Imaging
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• v.2 no.1
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• pp.73-82
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• 1998

Purpose : A precise NMR technique for measuring the rate of water exchange and cell membrane permeability across the hepatocyte membrane using liver-specific MR contrast agent is described. Materials and Methods : The rat hepatocytes isolated by perfusion of the livers were used for the NMR measurements. All experiments were performed on an IBM field cycling relaxometer operating from 0.02MHz to 60 MHz proton Larmor frequency. spin-echo pulse sequence was empolyed to measure spin-lattice relaxation time, T1. The continuous distribution analysis of water proton T1 data from rat hepatocytes containing low concentrations of the liver specific contrast agent, Gd-EOB-DTPA, modeled by a general two compartment exchange model. Results : The mean residence time of water molecule inside the hepatocyte was approximately 250 msec. The lower limit for the permeability of the hepatocyte membrane was $(1.3{\pm}0.1){\;}{\times}{\;}10^{-3}cm/sec$. The CONTIN analysis, which seeks the natural distribution of relaxation times, reveals direct evidence of the effect of diffusive exchange. the diffusive water exchange is not small in the intracellular space in the case of hepatocytes. Conclusions : Gd-EOB-DTPA, when combined with continuous distribution analysis, provides a robust method to study water exchange and membrane permeability in hepatocytes. Water exchange in hepatocyte is much slower thatn that in red blood cells. Therefore, tissue-specific contrast agent may be used as a functional agent to give physiological information such as cell membrane permeability.

• Korean Journal of Food Science and Technology
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• v.48 no.5
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• pp.454-460
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• 2016

In this study, we investigated the possibility of Droplet digital PCR (ddPCR) for detection of foodborne pathogens. ddPCR combines partitioning of PCR reactions into several thousands or millions of individual droplets in a water-oil emulsion, and counting of positive PCR reaction using flow cytometry. Four species of foodborne pathogens, Bacillus cereus, Staphylococcus aureus, Salmonella Typhimurium and Escherichia coli O157:H7, were used to quantify the target sequence with each of the designed primers and double stranded DNA-binding Evagreen dye. All tested foodborne pathogens showed a detection limit ranging from $100fg/{\mu}L$ to $10ng/{\mu}L$. It was concluded that ddPCR could be used to detect very low concentrations of foodborne pathogens from complex food matrices. For multi-detection of target pathogens, we also tested the samples using multiplex ddPCR and obtained successful results.

• Food Science of Animal Resources
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• v.33 no.5
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• pp.655-663
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• 2013

In this study, a rapid and sensitive detection tool for screening Salmonella spp. by using a loop-mediated isothermal amplification (LAMP) assay targeting the genomic sequence of the invA gene was developed. The inclusivity and exclusivity were both at 100% in the analysis, and the limit of detection (LOD) in a pure S. Enteritidis culture suspended in saline was $3.2{\times}10^3$ CFU/mL at 18.17 min ($R^2$ = 0.9446). The LODs of the LAMP assay in buffered peptone water with Salmonella (BPW) and duck carcass swab sample enriched in BPW with Salmonella (BPWS) after 0 and 12 h incubation were $3.2{\times}10^3$ CFU/mL and $3.2{\times}10^0$ CFU/mL, respectively. Comparing the LODs in BPW with those in BPWS, the LAMP assay was less influenced by compounds of duck carcass swab sample than the PCR assay. Sensitivity and specificity of the LAMP assay in 50 duck carcass swab samples enriched in BPW for 6 h were 96% and 84%, respectively, indicating that the LAMP assay is a rapid, simple and sensitive assay, which can be utilized as a potential screening tool of Salmonella spp. in duck carcass sample.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.8
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• pp.639-651
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• 2018

An analytical solution to generate attitude command profile for agile spacecraft is proposed. In realistic environment, obtaining analytical minimum-time optimal solution is very difficult because of following constraints-: 1) actuator saturation, 2) flexible mode excitation, 3) uplink command bandwidth limit. For that reasons, this paper applies two simplifications, an eigen-axis rotation and a finite-jerk approximated profile, to derive the solution in an analytical manner. The resulting attitude profile can be used as a feedforward or reference input to on-board attitude controller, and it can enhance spacecraft agility. Equations of attitude command profile are derived in two general boundary conditions: rest-to-rest maneuver and spin-to-spin maneuver. Simulation results demonstrate that the initial and final boundary conditions, in terms of time, attitude, and angular velocities, are well satisfied with the proposed analytical solution. The derived attitude command generation algorithm may be used to minimize a number of parameters to be uploaded to spacecraft or to automate a sequence of attitude command generation on-board.

• Journal of Intelligence and Information Systems
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• v.16 no.4
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• pp.195-211
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• 2010

An exhibition is defined as market events for specific duration to present exhibitors' main product range to either business or private visitors, and it also plays a key role as effective marketing channels. Especially, as the effect of the opinions of the visitors after the exhibition impacts directly on sales or the image of companies, exhibition organizers must consider various needs of visitors. To meet needs of visitors, ubiquitous technologies have been applied in some exhibitions. However, despite of the development of the ubiquitous technologies, their services cannot always reflect visitors' preferences as they only generate information when visitors request. As a result, they have reached their limit to meet needs of visitors, which consequently might lead them to loss of marketing opportunity. Recommendation systems can be the right type to overcome these limitations. They can recommend the booths to coincide with visitors' preferences, so that they help visitors who are in difficulty for choices in exhibition environment. One of the most successful and widely used technologies for building recommender systems is called Collaborative Filtering. Traditional recommender systems, however, only use neighbors' evaluations or behaviors for a personalized prediction. Therefore, they can not reflect visitors' dynamic preference, and also lack of accuracy in exhibition environment. Although there is much useful information to infer visitors' preference in ubiquitous environment (e.g., visitors' current location, booth visit path, and so on), they use only limited information for recommendation. In this study, we propose a booth recommendation methodology using Sequential Association Rule which considers the sequence of visiting. Recent studies of Sequential Association Rule use the constraints to improve the performance. However, since traditional Sequential Association Rule considers the whole rules to recommendation, they have a scalability problem when they are adapted to a large exhibition scale. To solve this problem, our methodology composes the confidence database before recommendation process. To compose the confidence database, we first search preceding rules which have the frequency above threshold. Next, we compute the confidences of each preceding rules to each booth which is not contained in preceding rules. Therefore, the confidence database has two kinds of information which are preceding rules and their confidence to each booth. In recommendation process, we just generate preceding rules of the target visitors based on the records of the visits, and recommend booths according to the confidence database. Throughout these steps, we expect reduction of time spent on recommendation process. To evaluate proposed methodology, we use real booth visit records which are collected by RFID technology in IT exhibition. Booth visit records also contain the visit sequence of each visitor. We compare the performance of proposed methodology with traditional Collaborative Filtering system. As a result, our proposed methodology generally shows higher performance than traditional Collaborative Filtering. We can also see some features of it in experimental results. First, it shows the highest performance at one booth recommendation. It detects preceding rules with some portions of visitors. Therefore, if there is a visitor who moved with very a different pattern compared to the whole visitors, it cannot give a correct recommendation for him/her even though we increase the number of recommendation. Trained by the whole visitors, it cannot correctly give recommendation to visitors who have a unique path. Second, the performance of general recommendation systems increase as time expands. However, our methodology shows higher performance with limited information like one or two time periods. Therefore, not only can it recommend even if there is not much information of the target visitors' booth visit records, but also it uses only small amount of information in recommendation process. We expect that it can give real?time recommendations in exhibition environment. Overall, our methodology shows higher performance ability than traditional Collaborative Filtering systems, we expect it could be applied in booth recommendation system to satisfy visitors in exhibition environment.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.11
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• pp.140-149
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• 1996

Cursive characters are written on an economical principle to reduce the motion of a pen in the limit of distinction between characters. That is, the pen is not lifted up to move for writing a next stroke, the pen is not moved at all, or connected two strokes chance their shapes to a similar and simple shape which is easy to be written. For these reasons, strokes and korean alphabets are not only easy to be changed, but also difficult to be splitted. In this paper, we propose a curvature stroke modeling method for splitting and matching by using a structural primitive. A curvature stroke is defined as a substroke which does not change its curvanture. Input strokes handwritten in a cursive style are splitted into a sequence of curvature strokes by segmenting the points which change the direction of rotation, which occur a sudden change of direction, and which occur an excessive rotation Each reference of korean alphabets is handwritten in a printed style and is saved as a sequence of curvature strikes which is generated by splitting process. And merging process is used to generate various sequences of curvature strikes for matching. Here, it is also considered that imaginary strokes can be written or omitted. By using a curvature stroke as a unit of recognition, redundant splitting points in input characters are effectively reduced and exact matching is possible by generating a reference curvature stroke, which consists of the parts of adjacent two korean alphasbets, even when the connecting points between korean alphabets are not splitted. The results showed 83.6% as recognition rate of the first candidate and 0.99sec./character (CPU clock:66MHz) as processing time.