• Journal of Digital Convergence
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• v.15 no.8
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• pp.391-400
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• 2017

The purpose of this paper is to present the effect of image stimulation on body stability as a conceptual model and to investigate the effect of image stimulus(2D, VR) on body stability(hand stability) through experiments Recently, stereoscopic images such as virtual and augmented reality are combined with smart phones and exercise equipments, and the diffusion is becoming active. The possibility of a safety accident or human error is also increasing as it temporarily affects the balance of the body and hand stability after the image stimulus is removed. The conceptual model is presented based on the results of previous studies. Based on the experimental results, the conceptual model has been explained in combination with the human information processing process and cognitive resource models that take place in the brain. Twenty subjects were exposed to 2D and VR stimuli, and display fatigue was measured by cybersickness questionnaire and hand stability by hand steadiness tester. Experimental results show that VR images induce higher display fatigue and lower hand stability than 2D. In this study, it is meaningful that hand stability according to image type and display fatigue level which have not been tried yet is revealed through conceptual model and experiment.

• Journal of Internet Computing and Services
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• v.15 no.6
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• pp.107-115
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• 2014

Recently, increased use of the internet resulted in generation of large and diverse types of data due to increased use of social media, expansion of a convergence of among industries, use of the various smart device. We are facing difficulties to manage and analyze the data using previous data processing techniques since the volume of the data is huge, form of the data varies and evolves rapidly. In other words, we need to study a new approach to solve such problems. Many approaches are being studied on this issue, and we are describing an effective design and development to build indexing engine of big data platform. Our goal is to build a system that could effectively manage for huge data set which exceeds previous data processing range, and that could reduce data analysis time. We used large SNMP log data for an experiment, and tried to reduce data analysis time through the fast indexing and searching approach. Also, we expect our approach could help analyzing the user data through visualization of the analyzed data expression.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.216-221
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• 2016

This study was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 35% paraformaldehyde against Salmonella Typhimurium (S. Typhimurium). In this study, the efficacy test of a fumigant against S. Typhimurium was carried out according to French standard NF T 72-281. The S. Typhimurium working culture suspension number (N value), all bacteria numbers on the carriers exposed to the fumigant (n1, n2, and n3), the number of bacterial suspensions by the pour plate method (N1), the number of bacterial suspensions by the filter membrane method (N2), and the mean number of bacteria recovered on the control carriers (T value), were obtained from the preliminary test. In addition, the reduction number of S. Typhimurium exposed to the fumigant (d value) was calculated using the T value, the mean number of bacteria in the recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). The N value was $5.5{\times}10^8$ colony forming units (CFU)/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, the T value was $3.5{\times}10^6CFU/carrier$. In terms of the bactericidal effect of the fumigant, the d value was 5.25. According to the French standard for fumigants, the d value for an effective bactericidal fumigant should be greater than 5. The results indicated that the fumigant containing 35% paraformaldehyde had an efficient bactericidal activity against S. Typhimurium, and, therefore, can be used to disinfect food materials and kitchen appliances contaminated with foodborne bacteria.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.9
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• pp.1143-1150
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• 2017

The aim of this study was to determine the chemical and intracellular antioxidant activities of ${\beta}$-carotene and lycopene and to compare their quantitative structure-activity relationship (QSAR). In our previous study, the second ionization energy of lycopene was higher than that of ${\beta}$-carotene, as calculated by QSAR. Chemical antioxidant activities of ${\beta}$-carotene, lycopene, and Trolox were examined by measuring ferric reducing antioxidant power (FRAP) and 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. Intracellular antioxidant activities were evaluated by intracellular reactive oxygen species (ROS) and DNA fragmentation. The FRAP of lycopene was higher than that of ${\beta}$-carotene (P<0.05), and the two carotenoids had similar antioxidant activities in DPPH radical scavenging activity assay. Trolox had the greatest chemical antioxidant activities (P<0.05). When RAW264.7 cells were treated with lipopolysaccharide (LPS) (100 ng/mL) for 20 h, intracellular ROS and DNA fragmentation significantly increased (P<0.05). RAW 264.7 cells pretreated with ${\beta}$-carotene ($4{\mu}M$) and lycopene ($0.4{\sim}2{\mu}M$) for 4 h formed significantly less intracellular ROS than LPS-treated control cells (P<0.05), whereas cells with Trolox did not reduce production of intracellular ROS. In addition, cells pretreated with $2{\mu}M$ lycopene produced less intracellular ROS than those treated with ${\beta}$-carotene (P<0.05). DNA fragmentation of cells with ${\beta}$-carotene and lycopene was similar to that of LPS-treated control cells as measured by Hoechst staining. The antioxidant ability of lycopene was greater than that of ${\beta}$-carotene in the QSAR, FRAP, and intracellular ROS assays (P<0.05). ${\beta}$-Carotene and lycopene had lower antioxidant activities as measured by FRAP (P<0.05) but higher intracellular protective effects against LPS-induced oxidative stress in comparison with Trolox.

• Journal of Korean Society for Geospatial Information Science
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• v.25 no.2
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• pp.13-19
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• 2017

This paper analyzed MODIS data from 2006 to 2013 to determine relationship between meteorological changes and vegetation index. The experimental area was divided into the northern, central and southern regions according to the regional characteristics, and the smoothed MODIS LAI and NDVI were obtained using Timesat. In the case of precipitation, MODIS NDVI had correlation coefficients of 0.66, 0.44 and 0.35 in the northern, central and southern regions and the correlation was the highest in the northern region. In the case of temperature, MODIS LAI had correlation coefficients of 0.66, 0.64 and 0.68, and MODIS NDVI had 0.89, 0.89 and 0.80. The correlation of MODIS NDVI was higher and showed similar positive correlation regardless of region. In addition, The accuracy between Timesat plant seasonal start and actual plant seasonal start in MODIS NDVI was higher than MODIS LAI. The average error in MODIS LAI was 19 days in the central region and 20 days in the southern region. And the average error in MODIS NDVI was 6 days in the central region and 8 days in the southern region.

• The Journal of the Korea Contents Association
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• v.11 no.11
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• pp.49-61
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• 2011

In recent, library is considered as an integrated knowledge convergence center that can respond to various requests about information service of users. Therefor it is necessary to establish a novel information system based on information communications technologies of the era. In other words, it is currently required to develop mobile information service available in portable devices such as smart phones or tablet PCs, and to establish information system reflecting cloud computing, SaaS, Annotation, and Library 2.0 etc. In this paper we design and implement a library information system using collective intelligence and cloud computing. This information system can be adapted for the varieties of mobile service paradigm and abruptly increasing amount of electronic materials. Advantages of this concept model are resource sharing, multi-tenant supporting, configuration, and meta-data supporting etc. In addition it can offer software on-demand type user services. In order to test the performance of our system, we perform an effectiveness analysis and TTA authentication test. The average response time corresponding to variance of data reveals 0.692 seconds which is very good performance in timing effectiveness point of view. And we detect maturity level-3 or 4 authentication in TTA tests such as SaaS maturity, performance, and application programs.

• Journal of Digital Convergence
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• v.15 no.5
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• pp.207-215
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• 2017

With rapid development of IT technology and biotechnology, human lifespan is extended rapidly, and we are living in the era where aging becomes the social issue. Due to this aging problem, manpower is mainly replaced by Automated Guided Vehicles (AGV) in manufacturing factories or warehouse logistics transportation. Rate of AGV use increases sharply every year. AGVs, which were used only in Smart Factories, extends its usage into indoor and outdoor operation by changing their usages to container transportation that can carry huge containers in the harbor. With the expansion of AGVs usage, the importance of RCS (Remote Control System) is also increased. In this study, we surveyed and analyzed the characteristics and technology trends of technical features of AGV's RCS that are developing in various ways to establish quality evaluation system of AGV RCS. Based on this, and by referring to international quality assessment standards, ISO/IEC 25000 series, we derived evaluation items on functional suitability and usability to secure reliability of AGV RCS. Also, it is our intention to develop evaluation model using those derived usability and reliability evaluation items.

• Journal of Food Hygiene and Safety
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• v.32 no.5
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• pp.418-423
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• 2017

An analytical method for the determination of dexamethasone (DM) in bovine milk samples was developed and validated using liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS). Milk samples were extracted by the liquid-liquid extraction based on acetonitrile. The chromatographic separation was achieved on a reverse phase $C_{18}$ column with gradient elution using a mobile phase of 0.1% formic acid in 95% acetonitrile. The procedure was validated according to the Ministry of Food and Drug Safety guideline determining accuracy, precision, limit of detection (LOD), and limit of quantification (LOQ). Mean recoveries of DM from spiked milk samples (25, 125, and 1,250 ng/mL) were 98.9-109.6%, and the relative standard deviation was between 1.7 and 4.4%. Linearity in concentration range of 12.5-1,250 ng/mL was obtained with the correlation coefficient ($r^2$) of 0.9997. LOD and LOQ for the investigated DM were 0.15 and 0.5 ng/mL depending on milk samples, respectively. This method was reliable, sensitive, economical and suitable for routine monitoring of DM residues in bovine milk.

• Journal of Internet Computing and Services
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• v.12 no.1
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• pp.99-110
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• 2011

Mobile environments rapidly changing and digital convergence widely employed, mobile devices including smart phones have been playing a critical role that changes users' lifestyle in the areas of entertainments, businesses and information services. The various services using mobile devices are developing to meet the personal needs of users in the mobile environments. Especially, an LBS (Location-Based Service) is combined with other services and contents such as augmented reality, mobile SNS (Social Network Service), games, and searching, which can provide convenient and useful services to mobile users. In this paper, we design and implement the prototype of mobile personal assistant (PA) agents. Our personal assistant agent helps users do some tasks by hiding the complexity of difficult tasks, performing tasks on behalf of the users, and reflecting the preferences of users. To identify user's preferences and provide personalized services, clustering and classification algorithms of data mining are applied. The clusters of the log data using clustering algorithms are made by measuring the dissimilarity between two objects based on usage patterns. The classification algorithms produce user profiles within each cluster, which make it possible for PA agents to provide users with personalized services and contents. In the experiment, we measured the classification accuracy of user model clustered using clustering algorithms. It turned out that the classification accuracy using our method was increased by 17.42%, compared with that using other clustering algorithms.

• Journal of Food Hygiene and Safety
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• v.31 no.4
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• pp.299-303
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• 2016

Salmonella spp. and Brucella spp. can cause considerable diseases on both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a disinfectant spray, composed to grapefruit seed extract, citric acid, malic acid and benzalkonium chloride, was evaluated against S. Typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant spray against S. Typhimurium and B. ovis was 5 and 4 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant spray was 2 and 1 fold dilutions against S. Typhimurium and B. ovis, respectively. As the disinfectant spray possesses bactericidal efficacy against foodborne pathogens such as S. Typhimurium and B. ovis, the disinfectant spray can be used to control the spread of bacterial diseases.