• Journal of Broadcast Engineering
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• v.24 no.6
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• pp.1134-1142
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• 2019

Detection of double compression is one of the most efficient ways of remarking the validity of videos. Many methods have been introduced to detect HEVC double compression with different coding parameters. However, HEVC double compression detection under the same coding environments is still a challenging task in video forensic. In this paper, we introduce a novel method based on the frame partitioning information in intra prediction mode for detecting double compression in with the same coding environments. We propose to extract statistical feature and Deep Convolution Neural Network (DCNN) feature from the difference of partitioning picture including Coding Unit (CU) and Transform Unit (TU) information. Finally, a softmax layer is integrated to perform the classification of the videos into single and double compression by combing the statistical and the DCNN features. Experimental results show the effectiveness of the statistical and the DCNN features with an average accuracy of 87.5% for WVGA and 84.1% for HD dataset.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.26 no.4
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• pp.885-894
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• 2016

As smartphones become more common, anybody can take pictures and record videos easily nowadays. Video files taken from smartphones can be used as important clues and evidence. While you analyze video files taken from smartphones, there are some occasions where you need to prove that a video file was recorded by a specific smartphone. To do this, you can utilize various fingerprint techniques mentioned in existing research. But you might face the situation where you have to strengthen the result of fingerprinting or fingerprint technique can't be used. Therefore forensic investigation of the smartphone must be done before fingerprinting and the database of metadata of video files should be established. The artifacts in a smartphone after video recording and the database mentioned above are discussed in this paper.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.559-572
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• 2020

As internet technology advances, users can share content online, and many sharing services exist. According to a recently published digital forensic study, when playing an online streaming service, you can restore the played video by reconstructing the Chrome cache file left on local device such as a PC. This can be seen as evidence that the user watched illegal video content. From a different point of view, copyright infringement occurs when a malicious user restores video stream and share it to another site. In this paper, we selected 23 online streaming services that are widely used both at home and abroad. After streaming videos, we tested whether we can recover original video using cache files stored on the PC or not. As a result, the paper found that in most sites we can restore the original video by reconstructing cache files. Furthermore, this study also discussed methodologies for preventing copyright infringement in online streaming service.

• Journal of the Korea Society of Computer and Information
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• v.17 no.12
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• pp.95-100
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• 2012

In this paper, we see the means for the assault, the type of unlawful exercise of power. Also, we see the violence, the physical exercise accompanying with assault. Now, it has caused numerous crimes in elevators. This paper is to present a way to extract the violence and assault that occurred in elevators. Key frame was extract by color histogram method, one of the ways to scene change detection techniques. Extracted key frames are key frames of a scene containing a forensic crime scene video. Also, the key frames of the scene should be submitted to the forensic evidence.

• Journal of the Korea Society of Computer and Information
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• v.13 no.1
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• pp.253-260
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• 2008

This paper is based on the ubiquitous network of telematics technology, equipped with a black box to the car by a unique address given to IPv6. The driver's black box at startup and operation of certification, and the car's driving record handling video signals in real-time sensor signals handling to analyze the records. Through the recorded data is encrypted transmission, and the Ubiquitous network of base stations, roadside sensors through seamless mobility and location tracking data to be generated. This is a file of Transportation Traffic Operations Center as a unique address IPv6 records stored in the database. The car is equipped with a black box used on the road go to Criminal cases, the code automotive black boxes recovered from the addresses and IPv6, traffic records stored in a database to compare the data integrity verification and authentication via secure. This material liability in the courtroom and the judge Forensic data are evidence of the recognition as a highly secure. convenient and knowledge in the information society will contribute to human life.

• Korean Journal of Forensic Psychology
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• v.11 no.1
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• pp.1-20
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• 2020

Witnesses will be exposed to a variety of misinformation after the witnessing of the event and state at the scene of the investigation after the delay period. This study was conducted to promote correct recall reporting without being affected by factors that against correct recall. Self-Administered Interview(SAI) is known to obtain eyewitness accounts quickly and accurately. Therefore, we performed a SAI to see if it reported more information than the control group that did not perform the SAI. Also, it also performed that correct information was maintained without being affected by misinformation and delay. Eighty-eight participants were asked to perform SAI or game after showing a video of mock crime. Misinformation was presented in the first or second session to see if it affected recall. An analysis of responses from the final test conducted in the second session by participants showed that groups that conducted SAI after a four-week delay reported more correct information than control groups, while there was no difference between incorrect- and confabulation information. In particular, the timing of presenting misinformation did not affect the amount of recall. This suggests that conducting the SAI immediately after witnessing the event protects correct information even after four weeks. Finally, the significance and limitations of this study, and subsequent studies were discussed.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.33 no.4
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• pp.647-659
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• 2023

As digital evidence becomes more important in criminal investigations, disputes are increasing in court. As media diversifies and the scope of analysis expands, the level of expertise in digital forensics is also increasing. However, no competency model has been developed to define the capabilities of digital evidence examiners or to judge their expertise. There have been some studies that have derived the capabilities necessary for digital evidence examiner, but they are still insufficient. Therefore, in this study, 25 competency evaluation factors in a total of 9 competency groups were defined using methodologies such as expert FGI and Delphi survey. Specifically, it was defined as Digital Forensics Theory, Digital Evidence Collection&Management, Disk Forensics, Mobile Forensics, Video Forensics, infringement forensics, DB Forensics, Embedded(IoT) Forensics, and Cloud Forensics. The digital evidence examiner competency model is expected to be used in various fields such as recruitment, education and training, and performance evaluation in the future.

• The Journal of the Korea institute of electronic communication sciences
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• v.6 no.4
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• pp.533-537
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• 2011

The revision of the criminal procedure act in 2008 marked a great turnaround in the criminal trial system in our country, and the criminal trial system has been based on the trial priority principle from then on. People in general have been entitled to participate in criminal trials, which can be called the jury system, and their awareness of the law has consequently been taken to another level. And the principle of trial by evidence that requires fair process, explanation and scientific evidence is realized in a manner to be appropriate at people(jury)'s level. The prosecution was introduced a video recording system to ensure the efficiency of scientific criminal investigation and assisted every prosecutor's office across the nation to hire computer-added stenographers to back up the documentation of statements during video recording. The purpose of this study was to examine the Korean and foreign computer-added stenography systems and the prospect of computer-added stenography of the video recording system that has been utilized to make a scientific investigation. The effort by this study to look into the roles and prospect of computer-added stenography in the video recording system that has been introduced to improve the efficiency of scientific investigation, which the prosecution pursues, is expected to expedite the advancement of criminal investigation, to guarantee the protection of human rights and to shed new light on the importance and status of computer-added stenography in the trial priority principle.

• KIPS Transactions on Software and Data Engineering
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• v.6 no.1
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• pp.15-22
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• 2017

With the advance of Internet Technology, various social network services are created and used by users. Especially, the use of smart devices makes that multimedia contents can be used and distributed on social network services. However, since the crime rate also is increased by users with illegal purposes, there are needs to protect contents and block illegal usage of contents with multimedia forensics. In this paper, we propose a multimedia forensic technique which is identifying the video source. First, the scheme to acquire the sensor pattern noise (SPN) using morphology filtering is presented, which comes from the imperfection of photon detector. Using this scheme, the SPN of reference videos from the reference device is estimated and the SPN of an unknown video is estimated. Then, the similarity between two SPNs is measured to identify whether the unknown video is acquired using the reference device. For the performance analysis of the proposed technique, 30 devices including DSLR camera, compact camera, camcorder, action cam and smart phone are tested and quantitatively analyzed. Based on the results, the proposed technique can achieve the 96% accuracy in identification.

• Journal of Oral Medicine and Pain
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• v.21 no.1
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• pp.37-54
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• 1996

In this thesis, a new superimposition scheme using a computer vision system was proposed with 7 pairs of skull and ante-mortem photographs, which were already identified through other tests and DNA fingerprints at the Korea National Institute of Scientific Investigation. At this computer vision system, an unidentified skull was caught by video-camcoder with the MPEG and a ante-mortem photograph was scanned by scanner. These two images were processed and superimposed using pixel processing. Recognition of the individual identification by anatomical references was performed on the two superimposed images. These results were as followings. 1. For the enhancement of skull and ante-mortem photographs, various image processing schemes, such as SMOOTH, SHARPEN, EMBOSS, MOSAIC, ENGRAVE, INVERT, NEON and COLOR TO MONO, were applied using 3*5 window processing. As an image processing result of these methods, the optimal techniques were NEON, INVERT and ENGRAVE for the edge detection of skull and ante-mortem photograph. 2. Using various superimposition image processing techniques (SRCOR, SRCAND, SRCINVERT, SRCERASE, DSTINVERT, MERGEPAINT) were compared for the enhancement of image recognition. 3. By means of the video camera, the skull image was inputed directly to a computer system : superimposing it on the ante-mortem photograph made the identification more precise and time-saving. As mentioned above, this image processing techniques for the superimposition of skull and ante-mortem photographs simply used the previous approach, In other wrods, taking skull photographs and developing it to the same size as the ante-mortem photographs. This system using various image processing techniques on computer screen, a more precise and time-saving superimposition technique could be able to be applied in the area of individual identification in forensic practice.