• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.5
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• pp.303-314
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• 2018

In the past few years, government agencies and corporations have succumbed to stealthy, tailored cyberattacks designed to exploit vulnerabilities, disrupt operations and steal valuable information. Security Information and Event Management (SIEM) is useful tool for cyberattacks. SIEM solutions are available in the market but they are too expensive and difficult to use. Then we implemented basic SIEM functions to research and development for future security solutions. We focus on collection, aggregation and analysis of real-time logs from host. This tool allows parsing and search of log data for forensics. Beyond just log management it uses intrusion detection and prioritize of security events inform and support alerting to user. We select Elastic Stack to process and visualization of these security informations. Elastic Stack is a very useful tool for finding information from large data, identifying correlations and creating rich visualizations for monitoring. We suggested using vulnerability check results on our SIEM. We have attacked to the host and got real time user activity for monitoring, alerting and security auditing based this security information management.

• Journal of Intelligence and Information Systems
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• v.18 no.2
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• pp.47-60
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• 2012

Video data comes in the form of the unstructured and the complex structure. As the importance of efficient management and retrieval for video data increases, studies on the video parsing based on the visual features contained in the video contents are researched to reconstruct video data as the meaningful structure. The early studies on video parsing are focused on splitting video data into shots, but detecting the shot boundary defined with the physical boundary does not cosider the semantic association of video data. Recently, studies on structuralizing video shots having the semantic association to the video scene defined with the semantic boundary by utilizing clustering methods are actively progressed. Previous studies on detecting the video scene try to detect video scenes by utilizing clustering algorithms based on the similarity measure between video shots mainly depended on color features. However, the correct identification of a video shot or scene and the detection of the gradual transitions such as dissolve, fade and wipe are difficult because color features of video data contain a noise and are abruptly changed due to the intervention of an unexpected object. In this paper, to solve these problems, we propose the Scene Detector by using Color histogram, corner Edge and Object color histogram (SDCEO) that clusters similar shots organizing same event based on visual features including the color histogram, the corner edge and the object color histogram to detect video scenes. The SDCEO is worthy of notice in a sense that it uses the edge feature with the color feature, and as a result, it effectively detects the gradual transitions as well as the abrupt transitions. The SDCEO consists of the Shot Bound Identifier and the Video Scene Detector. The Shot Bound Identifier is comprised of the Color Histogram Analysis step and the Corner Edge Analysis step. In the Color Histogram Analysis step, SDCEO uses the color histogram feature to organizing shot boundaries. The color histogram, recording the percentage of each quantized color among all pixels in a frame, are chosen for their good performance, as also reported in other work of content-based image and video analysis. To organize shot boundaries, SDCEO joins associated sequential frames into shot boundaries by measuring the similarity of the color histogram between frames. In the Corner Edge Analysis step, SDCEO identifies the final shot boundaries by using the corner edge feature. SDCEO detect associated shot boundaries comparing the corner edge feature between the last frame of previous shot boundary and the first frame of next shot boundary. In the Key-frame Extraction step, SDCEO compares each frame with all frames and measures the similarity by using histogram euclidean distance, and then select the frame the most similar with all frames contained in same shot boundary as the key-frame. Video Scene Detector clusters associated shots organizing same event by utilizing the hierarchical agglomerative clustering method based on the visual features including the color histogram and the object color histogram. After detecting video scenes, SDCEO organizes final video scene by repetitive clustering until the simiarity distance between shot boundaries less than the threshold h. In this paper, we construct the prototype of SDCEO and experiments are carried out with the baseline data that are manually constructed, and the experimental results that the precision of shot boundary detection is 93.3% and the precision of video scene detection is 83.3% are satisfactory.

• Science of Emotion and Sensibility
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• v.18 no.2
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• pp.85-100
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• 2015

This study aimed at examining if the original memory remains after a misinformation is presented, using Event-Related Potential based Concealed Information Test (ERP-based CIT). In the first stage of the study, the participant was presented with either the original information or a misleading information after experiencing an event (Post-information). The second stage was to measure brain wave and reaction time on the original, misleading, and irrelevant information (CIT-Stimulus). P300 amplitude, P300 area, P300 latency, and reaction time were used as dependant variables. In the result, a significant Post-information ${\times}$ CIT-Stimulus interaction effect was found on the P300 area measured at Cz, Pz, and Oz area. This interaction effect implied the possibility that the original information could be partially impaired in memory by misleading information presented afterward. P300 amplitude at Pz area did not differ between the accurate and the misleading stimuli in the condition in which a misleading information was presented. This result can be explained by source monitoring error. In discussion, the limitations of this study and directions of future studies were discussed.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.7
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• pp.1313-1329
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• 2015

In MANET, frequent route breaks lead to repeated route discovery process and this increases control packet overhead and packet drop. AODV-I improves performance of AODV by using the event driven approach which removes periodic Hello message. Unlike the Hello message, Interrupt message which is sent for each event can detect and predict the link failure because it allows node to know the status of the neighbor node. From this characteristics of Interrupt message, performance of AODV-I can be further improved by adding a processing procedures for each type of Interrupt message and it is also possible to improve AODV-I by adding the Backup path scheme because it originally has problems due to a single path of AODV. In this paper, we propose AODV-IB that combines improved Backup path scheme and Interrupt message approach of AODV-I in order to reduce transmission delay and the number of route discoveries. AODV-IB improves AODV-I by adding proper processing procedures for the link failure prediction and detection for each Interrupt message. We also implement improved Backup path strategy in AODV-IB by minimizing delay without additional Control packet. Simulation results, using the simulator QualNet 5.0, indicate that proposed AODV-IB performs better than AODV-I.

• Korean Journal of Cognitive Science
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• v.23 no.2
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• pp.165-184
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• 2012

To investigate how the valence of unattended background picture modulates perceptual processing of a target letter, participants were required to detect a target letter among six letters superimposed on an IAPS picture. Perceptual load was manipulated by varying the difficulty of letter detection, and behavioral results showed more accurate and faster detection responses at the low-load condition than at the high-load condition. The analysis of ERP data of control condition at which six letters were presented without an IAPS picture showed perceptual load effects on mean amplitude of N1 and P1 ERP components. At experimental condition including an IAPS picture, interaction between valence and perceptual load was observed on mean amplitude of N1 at posterior visual processing area, and the amplitude difference between low-load condition and high-load condition was larger on a negative background picture than on a neutral background picture. The results suggest that more attentional capacity might be consumed by a negative picture than by a neutral picture, and suggest that unattended affective picture is processed automatically and influence the early perceptual processing of target stimulus.

• International Journal of Naval Architecture and Ocean Engineering
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• v.9 no.4
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• pp.446-459
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• 2017

Naval ships are assigned many and varied missions. Their performance is critical for mission success, and depends on the specifications of the components. This is why performance analyses of naval ships are required at the initial design stage. Since the design and construction of naval ships take a very long time and incurs a huge cost, Modeling and Simulation (M & S) is an effective method for performance analyses. Thus in this study, a simulation core is proposed to analyze the performance of naval ships considering their specifications. This simulation core can perform the engineering level of simulations, considering the mathematical models for naval ships, such as maneuvering equations and passive sonar equations. Also, the simulation models of the simulation core follow Discrete EVent system Specification (DEVS) and Discrete Time System Specification (DTSS) formalisms, so that simulations can progress over discrete events and discrete times. In addition, applying DEVS and DTSS formalisms makes the structure of simulation models flexible and reusable. To verify the applicability of this simulation core, such a simulation core was applied to simulations for the performance analyses of a submarine in an Anti-SUrface Warfare (ASUW) mission. These simulations were composed of two scenarios. The first scenario of submarine diving carried out maneuvering performance analysis by analyzing the pitch angle variation and depth variation of the submarine over time. The second scenario of submarine detection carried out detection performance analysis by analyzing how well the sonar of the submarine resolves adjacent targets. The results of these simulations ensure that the simulation core of this study could be applied to the performance analyses of naval ships considering their specifications.

• Journal of the Korea Institute of Military Science and Technology
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• v.20 no.5
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• pp.688-699
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• 2017

Model-based test, a well-known method of the black box tests, is consisted of the following four steps : model construction using requirement, test case generation from the model, execution of a SUT (software under test) and detection failures. Among models constructed in the first step, state-based models such as UML standard State Machine are commonly used to design event-based embedded systems (e.g., weapon control systems). To generate test cases from state-based models in the next step, coverage-based techniques such as state coverage and transition coverage are used. Round-trip path coverage technique using W-Method, one of coverage-based techniques, is known as more effective method than others. However it has a limitation of low failure observability because the W-Method technique terminates a testing process when arrivals meet states already visited and it is hard to decide the current state is completely same or not with the previous in the case like the GUI environment. In other words, there can exist unrevealed faults. Therefore, this study suggests a Extended W-Method. The Extended W-Method extends the round-trip path to a final state to improve failure observability. In this paper, we compare effectiveness and efficiency with requirement-item-based technique, W-Method and our Extended W-Method. The result shows that our technique can detect five and two more faults respectively and has the performance of 28 % and 42 % higher failure detection probability than the requirement-item-based and W-Method techniques, respectively.

• Publications of The Korean Astronomical Society
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• v.15 no.1
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• pp.15-19
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• 2000

The lens mass determined from the photometrically obtained Einstein time scale suffers from large uncertainty due to the lens parameter degeneracy. The uncertainty can be substantially reduced if the mass is determined from the lens proper motion obtained from astrometric measurements of the source image centroid shifts, ${\delta}{\theta}_c$, by using high precision interferometers from space-based platform such as the Space Interferometry Mission (SIM), and ground-based interferometers soon available on several 8-10m class telescopes. However, for the complete resolution of the lens parameter degeneracy it is required to determine the lens parallax by measuring the parallax-induced deviations in the centroid shifts trajectory, ${\Delta}{\delta}{\theta}_c$ aloe. In this paper, we investigate the detectabilities of ${\delta}{\theta}_c$ and ${\Delta}{\delta}{\theta}_c$ by determining the distributions of the maximum centroid shifts, $f({\delta}{\theta}_{c,max})$, and the average maximum deviations, $(<{\Delta}{\delta}_{c,max}>)$, for different types of Galactic microlensing events caused by various masses. From this investigation, we find that as long as source stars are bright enough for astrometric observations it is expected that $f({\delta}{\theta}_c)$ for most events caused by lenses with masses greater than 0.1 $M_\bigodot$ regardless of the event types can be easily detected from observations by using not only the SIM (with a detection threshold but also the ${\delta}{\theta}_{th}\;\~3{\mu}as)$ but also the ground-based interferometers $(with\;{\delta}{\theta}_{th}\;\~3{\mu}as)$. However, from ground-based observations, it will be difficult to detect ${\Delta}{\delta}{\theta}_c$ for most Galactic bulge self-lensing events, and the detection will be restricted only for small fractions of disk-bulge and halo-LMC events for which the deviations are relatively large. From observations by using the SIM, on the other hand, detecting ${\Delta}{\delta}{\theta}_c$ will be possible for majority of disk and halo events and for a substantial fraction of bulge self-lensing events. For the complete resolution of the lens parameter degeneracy, therefore, SIM observations will be essential.

• Journal of radiological science and technology
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• v.22 no.1
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• pp.5-11
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• 1999

This paper reviews recent major activities on instrumentation and methodology of PET. The performance of the PET instrumentation can be expressed by four physical characteristics, 1) spatial resolution, 2) coincidence resolving time, 3) energy resolution, and 4) detection efficiency. The physical and technical aspects of PET systems are briefly discussed along with these characteristics. Toward high resolution PET the recent trend has been to design multiple rings of densely packed detector arrays with scintillators. In order to satisfy the sampling requirement in reconstruction, continuous detector units has been developed. Iterative image reconstruction algorithms have received considerable attention for improvement of both the sampling requirement and image quality toward the stationary PET. Better resolving time improves the maximum true coincidence rate, which is also increased with more detectors placed in coincidence with each other. It suggests that volume PET is promising for enhancement of detection efficiency. The scattered coincidence event rate may be reduced by using detectors with better energy resolution. The use of interplane septa, however, takes over improvement of energy resolution in 2D PET. Energy resolution becomes an important factor for image quality under the condition of septa removal such as volume PET. Toward full utilization of emitting photons, 3D reconstruction incorporating oblique rays has been studied, and volume reconstruction algorithms have been developed. Practical volume PET systems impose heavy burden not only to detector sets and coincidence circuits, but also to computers in the memory requirements and the data processing. In conclusion, there have been many ingenious methods in development of PET instrumentation, which are based on unique capability of PET. They will be expected to overcome technical limitations, and to approach the fundamental limits.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.812-820
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• 2012

In this paper, multiple pedestrians tracking system using Histogram of Oriented Gradient and occlusion detection is proposed. The proposed system is applicable to Intelligent Surveillance System. First, we detect pedestrian in a image sequence using pedestrian's feature. To get pedestrian's feature, we make block-histogram using gradient's direction histogram based on HOG(Histogram of Oriented Gradient), after that a pedestrian region is classified by using Linear-SVM(Support Vector Machine) training. Next, moving objects are tracked by using position information of the classified pedestrians. And we create motion trajectory descriptor which is used for content based event retrieval. The experimental results show that the proposed method is more fast, accurate and effective than conventional methods.