• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.6
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• pp.43-54
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• 2016

The occurrence of cyber crime is on the rise every year, and the security control center, which should play a crucial role in monitoring and early response against the cyber attacks targeting various information systems, its importance has increased accordingly. Every endeavors to prevent cyber attacks is being attempted by information security personnel of government and financial sector's security control center, threat response Center, cyber terror response center, Cert Team, SOC(Security Operator Center) and else. The ordinary method to monitor cyber attacks consists of utilizing the security system or the network security device. It is anticipated, however, to be insufficient since this is simply one dimensional way of monitoring them based on signatures. There has been considerable improvement of the security control system and researchers also have conducted a number of studies on monitoring methods to prevent threats to security. In accordance with the environment changes from ESM to SIEM, the security control system is able to be provided with more input data as well as generate the correlation analysis which integrates the processed data, by extraction and parsing, into the potential scenarios of attack or threat. This article shows case studies how to detect the threat to security in effective ways, from the initial phase of the security control system to current SIEM circumstances. Furthermore, scenarios based security control systems rather than simple monitoring is introduced, and finally methods of producing the correlation analysis and its verification methods are presented. It is expected that this result contributes to the development of cyber attack monitoring system in other security centers.

• Journal of Broadcast Engineering
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• v.11 no.3 s.32
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• pp.363-378
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• 2006

The Digital Multimedia Broadcasting(DMB) system is developed to offer high quality audio-visual multimedia contents to the mobile environment. The system adopts MPEG-4 standard for the main video, audio and other media format. It also adopts the MPEG-4 scene description for interactive multimedia contents. The animated and interactive contents can be actualized by BIFS(Binary Format for Scene), the binary format for scene description that refers to the spatio-temporal specifications and behaviors of the individual objects. As more interactive contents are, the scene description is also needed more high bitrate. However, the bandwidth for allocating meta data such as scene description is restrictive in mobile environment. On one hand, the DMB terminal starts demultiplexing content and decodes individual media by its own decoder. After decoding each media, rendering module presents each media stream according to the scene description. Thus the BIFS stream corresponding to the scene description should be decoded and parsed in advance of presenting media data. With these reason, the transmission delay of BIFS stream causes the delay of whole audio-visual scene presentation although the audio or video streams are encoded in very low bitrate. This paper presents the effective optimization technique for adapting BIFS stream into expected MPEG-2 TS bitrate without any bandwidth waste and avoiding the transmission delay of the initial scene description for interactive DMB contents.

• Journal of the Korean earth science society
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• v.38 no.7
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• pp.522-534
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• 2017

The purpose of this study is to verify urban flow and thermal environment by using the simulated Computational Fluid Dynamics (CFD) model in the area of Gangnam Seonjeongneung, and then to compare the CFD model simulation results with that of Seonjeongneung-monitoring networks observation data. The CFD model is developed through the collaborative research project between National Institute of Meteorological Sciences and Seoul National University (CFD_NIMR_SNU). The CFD_NIMR_SNU model is simulated using Korea Meteorological Administration (KMA) Local Data Assimilation Prediction System (LDAPS) wind and potential temperature as initial and boundary conditions from August 4-6, 2015, and that is improved to consider vegetation effect and surface temperature. It is noticed that the Root Mean Square Error (RMSE) of wind speed decreases from 1.06 to $0.62m\;s^{-1}$ by vegetation effect over the Seonjeongneung area. Although the wind speed is overestimated, RMSE of wind speed decreased in the CFD_NIMR_SNU than LDAPS. The temperature forecast tends to underestimate in the LDAPS, while it is improved by CFD_NIMR_SNU. This study shows that the CFD model can provide detailed and accurate thermal and urban area flow information over the complex urban region. It will contribute to analyze urban environment and planning.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.8
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• pp.1188-1196
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• 2016

This study evaluated the risk of Clostridium perfringens (C. perfringens) foodborne illness from natural and processed cheeses. Microbial risk assessment in this study was conducted according to four steps: hazard identification, hazard characterization, exposure assessment, and risk characterization. The hazard identification of C. perfringens on cheese was identified through literature, and dose response models were utilized for hazard characterization of the pathogen. For exposure assessment, the prevalence of C. perfringens, storage temperatures, storage time, and annual amounts of cheese consumption were surveyed. Eventually, a simulation model was developed using the collected data and the simulation result was used to estimate the probability of C. perfringens foodborne illness by cheese consumption with @RISK. C. perfringens was determined to be low risk on cheese based on hazard identification, and the exponential model ($r=1.82{\times}10^{-11}$) was deemed appropriate for hazard characterization. Annual amounts of natural and processed cheese consumption were $12.40{\pm}19.43g$ and $19.46{\pm}14.39g$, respectively. Since the contamination levels of C. perfringens on natural (0.30 Log CFU/g) and processed cheeses (0.45 Log CFU/g) were below the detection limit, the initial contamination levels of natural and processed cheeses were estimated by beta distribution (${\alpha}1=1$, ${\alpha}2=91$; ${\alpha}1=1$, ${\alpha}2=309$)${\times}$uniform distribution (a = 0, b = 2; a = 0, b = 2.8) to be -2.35 and -2.73 Log CFU/g, respectively. Moreover, no growth of C. perfringens was observed for exposure assessment to simulated conditions of distribution and storage. These data were used for risk characterization by a simulation model, and the mean values of the probability of C. perfringens foodborne illness by cheese consumption per person per day for natural and processed cheeses were $9.57{\times}10^{-14}$ and $3.58{\times}10^{-14}$, respectively. These results indicate that probability of C. perfringens foodborne illness by consumption cheese is low, and it can be used to establish microbial criteria for C. perfringens on natural and processed cheeses.

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.118-128
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• 2015

Recently BIM technology has been expanded for using in construction project. Due to the high-cost of BIM infrastructure development, lack of regulations, lack of process and so forth, usage of BIM has been delayed than initial expectations. In design phase, especially, collaboration based on BIM system has been a key factor for successful next generation building project. Through the analysis of current research trends about IT technologies, virtualization and BIM service, data exchange such as drawings, 3D model, object data, properties using cloud computing and virtual server system is defined as a most successful solution. The purpose of this study is to enable the cloud computing BIM server to provide several main functions such as editing models, 3D model viewing and checking, mark-up and snapshot in high-performance quality by proper design of VDI system. Concurrent client connection performance is a main technical index of VDI. Through testing of test-bed server client, developed VDI system's multi-connect control is evaluated. Performance-test result of BIM server VDI effect to development direction of cloud computing BIM service for commercialization.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.31 no.3
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• pp.199-207
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• 2013

In hydrographic survey, data surveyed with multibeam system includes various errors due to multiple factors. These are corrected by a calibration called patch test, and if existing method is used, the test needs to be conducted for about 8 times for precise system calibration. For more prompt and precise multibeam system calibration, the exact offset of a ship was determined using terrestrial laser scanning and TS surveying, which was used as the initial input for the patch test. In the result, the error of closure was 0.001 m or less for TS surveying and backsight error was 0.005 m or less for scanning. All the surveying data based on the same local coordinate was converted into vessel reference coordinate during which R-square for all rotation angles was 0.99 or higher and standard deviation was 0.008 m or less. Finally, in a patch test using calculated offset of sensors and motion sensor offset, the offset of MBES transducer satisfied manual on hydrography only with 1-time calibration. With these results, it is thought that terrestrial laser scanning and TS surveying can fully be utilized for multibeam system calibration.

• Journal of Trauma and Injury
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• v.33 no.1
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• pp.31-37
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• 2020

Purpose: We aimed to evaluate the trauma volume and performance indicators during the first 5-year period of operation in a single regional trauma center. Methods: We analyzed prospectively collected data from the Korean Trauma Data Bank for a single regional trauma center between January 2014 and December 2018. More than 250 variables were analyzed. We calculated the predicted survival rates using the trauma and injury severity score (TRISS) method. Results: In total, there were 16,103 trauma admissions during the first 5 years; trauma activation was performed in 5,105 of these cases. Over 70% of the patients were men, and most of the admitted patients were within the age groups of 55-59 years for men and 75-79 years for women. Analyses were performed considering two patient groups: the total patient group and the group of those with severe trauma (injury severity score [ISS] >15). The median ISS, revised trauma score, and TRISS of the two groups were 5 (interquartile range [IQR] 4-10), 22 (IQR 17-27), and 7.6±0.99 and 6.74±1.9, 0.95±0.13, 0.81±2.67, respectively. Of the total patient group, 801 patients (5%) died in the hospital, whereas of the group of patients with ISS >15, 526 (19.5%) died. The direct transportation of patients to the regional trauma center increased year by year. The emergency room stay time and time to entering the operating room showed a decrease until 2017; however, these parameters increased again in 2018. Conclusions: The trauma volume in the regional trauma center is appropriate, and some improvements could be observed after its establishment. However, performance indicators reveal the prematurity of the trauma center and its potential for further improvements. Moreover, the development of a national trauma system, beyond regional trauma centers, is required.

• Korean Parent-Child Health Journal
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• v.3 no.1
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• pp.46-59
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• 2000

The purpose of this study is to determine whether the NCASA (Nursing Child Assessment Sleep/Activity Record) would be suitable to evaluate and to provide the basic resources for a Korean model of sleep/activity patterns during the first 6 months Korean infants' lives and to provide a basis for nursing intervention for mothers of early infants. The subjects of this study were 94 normal infants from birth to 6 months of age who visited the postpartum care center and two general hospitals located in Pusan from February 1 to April 28, 2000. The method of data collection was through convenient sampling. The instrument of this study was the NCASA translated by the Korean parent Child Health Academic Association. The collected data were analysed by mean, standard deviation, frequency percentage and ANOVA, Post Hoc test by use of SPSS/PC. The conclusions obtained from this study are summarized as follows: 1. The mean amount of daytime sleep was 8.06 hours. The mean amount of nighttime sleep was 6.31 hours. The mean amount of total daily sleep was 14.37 hours. The mean of the longest sleep period was 5.20 hours. The mean regularity of daytime sleep was 25.84%. The mean regularity of nighttime sleep was 77.69%. The mean regularity of total daily sleep was 42.60%. The mean frequency of nighttime wakenings was 2.33 times. 2. The mean amount of daytime activity was 8.25 hours. The mean amount of nighttime activity was 1.39 hours. The mean amount of daily total activity was 9.64 hours. The mean of the longest activity period was 3.80 hours The mean frequency of daytime feeding was 5.69 times. The mean frequency of nighttime feeding was 2.08 times. The mean frequency of total daily feeding was 7.74 times. The mean frequency regularity of feeding was 54.62%. The mean frequency of wakenings was 5.14 times. The mean frequency of crying was 1.90 times. 3. According to an analysis of sleep patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime sleep(p<.001), amount of night time sleep(p<.05), amount of total daily sleep (p<.001), longest sleep period(p<.001), regularity of daytime sleep(p<.001), regularity of nighttime sleep(p<.01), regularity of total daily sleep(p<.001), frequency of nighttime wakenings(p<.001). 4. According to an analysis of activity patterns based on an infant's age, there were some significant differences in the following factors: amount of daytime activity(p<.001), amount of nighttime activity(p<.01), amount of total daily activity(p<.001), longest activity period(p<.05), frequency of nighttime feeding(p<.01), frequency of wakenings(p<.001). 5. The mean amount of a mother's day time was 16.30 hours. The mean amount of a mother's night time was 7.70 hours. In conclusion, the initial irregular sleeping and activity patterns of the early infant became regurized as the infant grew older and estabilished firmer patterns of sleeping and of activity.

• The KIPS Transactions:PartB
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• v.12B no.6 s.102
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• pp.671-678
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• 2005

In this paper, we suggest an algorithm that allows us to extract the important obbject from motion pictures and then replace the background with arbitrary images. The suggested technique can be used not only for protecting privacy and reducing the size of data to be transferred by removing the background of each frame, but also for replacing the background with user-selected image in video communication systems including mobile phones. Because of the relatively large size of image data, digital image processing usually takes much of the resources like memory and CPU. This can cause trouble especially for mobile video phones which typically have restricted resources. In our experiments, we could reduce the requirements of time and memory for processing the images by restricting the search area to the vicinity of major object's contour found in the previous frame based on the fact that the movement of major object is not wide or rapid in general. Specifically, we detected edges and used the edge image of the initial frame to locate candidate-object areas. Then, on the located areas, we computed the difference image between adjacent frames and used it to determine and trace the major object that might be moving. And then we computed the contour of the major object and used it to separate major object from the background. We could successfully separate major object from the background and replate the background with arbitrary images.

• Restorative Dentistry and Endodontics
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• v.35 no.1
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• pp.24-29
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• 2010

The purpose of this study was to find out the relationship of radiographic lesion size, gender, age of patients and radiographic character to the diagnosis of periapical cyst and granuloma. The data was collected from 187 periapical lesions of 167 patients who undergone apical surgery at Department of Conservative Dentistry, Seoul National University Dental Hospital from 2003 to 2005. The lesion were surgically removed and send for biopsy to the Oral Pathology Laboratory. From the initial radiograph, lesion size was calculated using $PiViewSTAR^{(R)}$ (INFINITT, Korea) program. The obtained data were statistically evaluated using SPSS (p<0.05). The result were as followings: 1. From 187 biopsy samples, the incidence of periapical cyst was 28.34% and granuloma was 65.24%. 2. There was a significant correlation between periapical cyst and the size of radiographic lesion (p<0.01). 3. There were no significant correlations between age, gender, location of lesion and the final diagnosis (p>0.05). 4. There was a significant correlation between the non-demarcation of the lesion and the incidence of periapical granuloma (p<0.01).