• Title/Summary/Keyword: information recovering

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A Review Study on Recognition of Teachers for Information System of School Library (학교도서관의 정보시스템에 관한 교사들의 인식도 조사 연구)

  • 유양근
    • Journal of Korean Library and Information Science Society
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    • v.34 no.2
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    • pp.19-42
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    • 2003
  • The purpose of this study is to identify the way of development of school library and construction of information system for school library. In order to identify the way, the school librarian recognition level of school library information system was analyzed, since the recognition level about the information system can affect the school library development. Data is collected through the questionnaire. The result can be used to develope a school library instruction program for teachers and a base material for recovering the school library fundamental function.

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Floated Wafer Motion Modeling of Clean Tube system

  • Shin, Dong-Hun;Yun, Chung-Yong;Jeong, Kyoo-Sik;Choi, Chul-Hwan
    • 제어로봇시스템학회:학술대회논문집
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    • 2004.08a
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    • pp.1264-1268
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    • 2004
  • This paper presents a wafer motion modeling of the transfer unit and the control unit in the clean tube system, which was developed as a means for transferring the air-floated wafers inside the closed tube filled with the super clean airs. The motion in the transfer unit is modeled as a mass-spring-damper system where the recovering force by air jets issued from the perforated plate is modeled as a linear spring. The motion in the control unit is also modeled as another mass-spring-damper system, but in two dimensional systems. Experiments with a clean tube system built for 12-inch wafers show the validity of the presented force and motion models.

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Recovering Surface Orientation from Texture Gradient by Monoculer View (단안시에 의한 무늬그래디언트로부터 연 방향 복구)

  • 정성칠;최연성;최종수
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1987.04a
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    • pp.22-26
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    • 1987
  • Texture provides an important acurce of information about the threedicensfornarry information of visible surface particulary for stationary conccular views. To recover three dicmensinoary information, the distorging effects of pro jection must be distinguished from properties of the texture on which the distrortion acts. In this paper, we show an approximated maximum likelihood estimation method by which we find surface oriemtation of the visible surface in gaussian sphere using local analysis of the texture, In addition assuming that an orthographic projection and a circle is an image formation system and a texel(texture element)respectively we derive the surface orientation from the distribution of variation by means of orthographic pro jemction of a tangent directon which exstis regulary in the are length of a circle we present the orientation parameters of textured surface with saint and tilt and also the surface normal of the resvlted surface orimentation as needle map. This algorithm was applied to geograghic contour and synthetic textures.

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Adaptive Reversal Tree Protocol with Optimal Path for Dynamic Sensor Networks

  • Hwang, Kwang-Il
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.10A
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    • pp.1004-1014
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    • 2007
  • In sensor networks, it is crucial to reliably and energy-efficiently deliver sensed information from each source to a sink node. Specifically, in mobile sink (user) applications, due to the sink mobility, a stationary dissemination path may no longer be effective. The path will have to be continuously reconfigured according to the current location of the sink. Moreover, the dynamic optimal path from each source to the sink is required in order to reduce end-to-end delay and additional energy wastage. In this paper, an Adaptive Reversal Optimal path Tree (AROT) protocol is proposed. Information delivery from each source to a mobile sink can be easily achieved along the AROT without additional control overhead, because the AROT proactively performs adaptive sink mobility management. In addition, the dynamic path is optimal in terms of hop counts and the AROT can maintain a robust tree structure by quickly recovering the partitioned tree with minimum packet transmission. Finally, the simulation results demonstrate that the AROT is a considerably energy-efficient and robust protocol.

Analysis of Color Constancy Methods for Recovering Skin Color Independent of Illuminants (광원에 독립적인 피부색 복원을 위한 색 항등성 기법 분석)

  • Lee, Woo-Ram;Hwang, Dong-Guk;Jun, Byoung-Min
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.36 no.10C
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    • pp.621-628
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    • 2011
  • The skin color has been used as important cues in the systems for detecting or recognizmg the face. However, the color difference in images under different illuminants makes it difficult to find out the skin in these systems. For solving the problem, this paper proposes a method of recovering skin colors based on well-known color constancy approaches, such as Retinex, Gray World, White Patch, and Simplified Horn. To acquire experimental images under the colored scene illumination, the effects of colored illuminants were added to source images. Next, result images, having the corrected skin color by the constancy methods, were derived from the source images. The experiment results showed that most of the skin colors in our experiments were recovered into some steady range in the color space, and that Gray World had higher performance than the other methods compared.

Developing Expert System for Recovering the Original Form of Ancient Relics Based on Computer Graphics and Image Processing (컴퓨터 그래픽스 및 영상처리를 이용한 문화 원형 복원 전문가시스템 개발)

  • Moon, Ho-Seok;Sohn, Myung-Ho
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.6 s.44
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    • pp.269-277
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    • 2006
  • We propose a new expert system for recovering the broken fragments of relics into an original form using computer graphics and image processing. This paper presents a system with an application to tombstones objects of flat plane with letters carved in for assembling the fragments by placing their respective fragments in the right position. The matching process contains three sub-processes: aligning the front and letters of an object, identifying the matching directions, and determining the detailed matching positions. We apply least squares fitting, vector inner product, and geometric and RGB errors to the matching process. It turned out that 2-D translations via fragments-alignment enable us to save the computational load significantly. Based on experimental results from the damaged cultural fragments, the performance of the proposed method is illustrated.

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An Effective Method for Replacing Caption in Video Images (비디오 자막 문자의 효과적인 교환 방법)

  • Chun Byung-Tae;Kim Sook-Yeon
    • Journal of the Korea Society of Computer and Information
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    • v.10 no.2 s.34
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    • pp.97-104
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    • 2005
  • Caption texts frequently inserted in a manufactured video image for helping an understanding of the TV audience. In the movies. replacement of the caption texts can be achieved without any loss of an original image, because the caption texts have their own track in the films. To replace the caption texts in early methods. the new texts have been inserted the caption area in the video images, which is filled a certain color for removing established caption texts. However, the use of these methods could be lost the original images in the caption area, so it is a Problematic method to the TV audience. In this Paper, we propose a new method for replacing the caption text after recovering original image in the caption area. In the experiments. the results in the complex images show some distortion after recovering original images, but most results show a good caption text with the recovered image. As such, this new method is effectively demonstrated to replace the caption texts in video images.

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Analyzing Past User History through Recovering Deleted $UsnJrnl file (삭제된 $UsnJrnl 파일 복구를 통한 과거 사용자 행위 확인)

  • Kim, Dong-Geon;Park, Seok-Hyeon;Jo, Ohyun
    • Journal of Convergence for Information Technology
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    • v.10 no.5
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    • pp.23-29
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    • 2020
  • These days, digital forensic technologies are being used frequently at crime scenes. There are various electronic devices at the scene of the crime, and digital forensic results of these devices are used as important evidence. In particular, the user's action and the time when the action took place are critical. But there are many limitations for use in real forensics analyses because of the short cycle in which user actions are recorded. This paper proposed an efficient method for recovering deleted user behavior records and applying them to forensics investigations, then the proposed method is compared with previous methods. Although there are difference in recovery result depending on the storage, the results have been identified that the amount of user history data is increased from a minimum of 6% to a maximum of 539% when recovered user behavior was utilized to forensics investigation.

Side-Channel Cryptanalysis on Stream Cipher HC-128 for Mobile Ad-Hoc Network Environments (이동 Ad-Hoc 네트워크 환경에 적합한 스트림 암호 HC-128의 부채널 안전성 분석)

  • Bae, KiSeok;Park, YoungHo;Moon, SangJae
    • Journal of Korea Society of Industrial Information Systems
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    • v.17 no.6
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    • pp.11-17
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    • 2012
  • The HC-128 stram cipher which selected for the final eSTREAM portfolio is suitable for mobile Ad-Hoc network environments because of the ability of high-speed encryption in restricted memory space. In this paper, we analyzed the vulnerability of side channel analysis attack on HC-128 stream cipher. At the first, we explain a flaw of previous theoretical analysis result which defined the complexity of side-channel attack of HC-128 stream cipher as 'low' and then re-evaluate the security against side-channel attack by estimating the concrete complexity for recovering the secret key. As a result, HC-128 stream cipher is relatively secure against side-channel attack since recovering the secret key have $2^{65}$ computation complexity which is higher than other stream cipher's one.

Comparing Recoverability of Deleted Data According to Original Source Collection Methods on Microsoft SQL Server (Microsoft SQL Server의 원본 수집 방식에 따른 삭제 데이터의 복구 가능성 비교)

  • Shin, Jiho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.28 no.4
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    • pp.859-868
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    • 2018
  • Previous research related to recovering deleted data in database has been mainly based on transaction logs or detecting and recovering data using original source files by physical collection method. However there was a limit to apply if the transaction log does not exist in the server or it is not possible to collect the original source file because a database server owner does not permit stopping the database server because of their business loss or infringement at the scene. Therefore it is necessary to examine various collection methods and check the recoverability of the deleted data in order to handling the constraints of evidence collection situation. In this paper we have checked an experiment that the recoverability of deleted data in the original database source according to logical and physical collection methods on digital forensic investigation of Microsoft SQL Server database.