• Title/Summary/Keyword: Deleted Data

Search Result 219, Processing Time 0.033 seconds

On the Weak Law of Large Numbers for the Sums of Sign-Invariant Random Variables (대칭확률변수(對稱確率變數)의 대수(對數)의 법칙(法則)에 대하여)

  • Hong, Dug-Hun
    • Journal of the Korean Data and Information Science Society
    • /
    • v.4
    • /
    • pp.53-63
    • /
    • 1993
  • We consider various types of weak convergence for sums of sign-invariant random variables. Some results show a similarity between independence and sign-invariance. As a special case, we obtain a result which strengthens a weak law proved by Rosalsky and Teicher [6] in that some assumptions are deleted.

  • PDF

A Secure Deletion Method for NAND Flash File System (NAND 플래시 파일 시스템을 위한 안전 삭제 기법)

  • Lee, Jae-Heung;Oh, Jin-Ha;Kim, Seok-Hyun;Yi, Sang-Ho;Heo, Jun-Young;Cho, Yoo-Kun;Hong, Ji-Man
    • Journal of KIISE:Computing Practices and Letters
    • /
    • v.14 no.3
    • /
    • pp.251-255
    • /
    • 2008
  • In most file systems, if a file is deleted, only the metadata of the file is deleted or modified and the file's data is still stored on the physical media. Some users require that deleted files no longer be accessible. This requirement is more important in embedded systems that employ flash memory as a storage medium. In this paper, we propose a secure deletion method for NAND flash file system and apply the method to YAFFS. Our method uses encryption to delete files and forces all keys of a specific file to be stored in the same block. Therefore, only one erase operation is required to securely delete a file. Our simulation results show that the amortized number of block erases is smaller than the simple encryption method. Even though we apply our method only to the YAFFS, our method can be easily applied to other NAND flash file systems.

Scale Development on Health Conservation of the Institutionalized Elderly (시설 노인의 건강보존에 관한 도구 개발)

  • Sung, Ki-Wol
    • Journal of Korean Academy of Nursing
    • /
    • v.35 no.1
    • /
    • pp.113-124
    • /
    • 2005
  • Purpose: The purpose of this study was to develop a health conservation scale with high validity and reliability for institutionalized elderly. Method: The process of development of this scale was as follows. A conceptual framework composed of 4 phases of health conservation of institutionalized elderly was identified based on the literature review with elderlies and discussions with experts in health conservation. A total of 75 items, on a 4-point scale were developed. Through reliability testing and factor analysis, 57 preliminary items were selected. By means of internal consistency of the 57 items, 18 items whose inner-items correlation coefficient was below .40 were deleted. Through factor analysis, 2 items whose factor loading was below .40 were deleted. Finally 37 items remained. To verity the 37 items, factor analysis, reliability testing, and correlation was done. Data were collected from 207 institutionalized elderly subjects in Daegu, Kyungpook, Busan, and KyungNam Province from August. 2003 to February. 2004. Result: In the result of factor analysis of the 37 items, 4 factors were extracted. These factors were labeled as ‘personal integrity’, ‘conservation of energy', ‘structural integrity’, and ‘social integrity'. These factors included 4 phases of health conservation. Cronbach's Alpha of 37 the items was .9424 and the correlation coefficient of HPLP was .723. Conclusion: The researchers recommend the following: An explorative study on the variables related to health conservation is needed for criterion validity of this scale. Studies on health conservation of different age groups, and subjects are needed for verification.

Development of Elderly Meaning in Life (EMIL) Scale (노인의 생의 의미 측정 도구 개발)

  • 최순옥;김숙남;신경일;이정지;정유진
    • Journal of Korean Academy of Nursing
    • /
    • v.33 no.3
    • /
    • pp.414-424
    • /
    • 2003
  • Purpose: The purpose of this study was to develop elderly meaning in life scale with high validity and reliability. Method: The process of development of this scale were as follows. A conceptual framework composed of 4 phases of meaning in life of elderly was identified based on the literature review and interviews with elderlies and discussion with experts in meaning in life. Total 62 items, 4-points scale were developed. Through reliability testing, factor analysis, 40 preliminary items were selected. By means of internal consistency of 40 items, 2 items whose inner-items correlation coefficient was below .30 were deleted. Through factor analysis 1 item whose factor loading was below .30 was deleted. Finally 37 items were remained. To verify 37 items, factor analysis, reliability testing, LISEREL were done. Data were collected from 320 elderly subjects in Busan-KyungNam and Jeonla Province from May to June in 2002. SPSS WIN. 10.0 Program was used. Result: The result of factor analysis of 37 items, 8 factors were extracted. These factors were labeled as ‘self- awareness and self-acceptance’, ‘contentedness with life’, ‘purpose in life’, ‘love in family’, ‘role awareness’, ‘futuristic aspiration’, ‘commitment’, and ‘experience of love’. These factors included 4 phases of the meaning in life. Cronbach's Alpha of 37 items was .908 and correlation coefficient of PIL was .75. Conclusion: The researchers recommend the follows: The explorative study on the variables related to meaning in life are needed for criterion validity of this scale. The studies on meaning in life of different age groups, subjects are needed for reverification.

Multi-temporal Remote-Sensing Imag e ClassificationUsing Artificial Neural Networks (인공신경망 이론을 이용한 위성영상의 카테고리분류)

  • Kang, Moon-Seong;Park, Seung-Woo;Lim, Jae-Chon
    • Proceedings of the Korean Society of Agricultural Engineers Conference
    • /
    • 2001.10a
    • /
    • pp.59-64
    • /
    • 2001
  • The objectives of the thesis are to propose a pattern classification method for remote sensing data using artificial neural network. First, we apply the error back propagation algorithm to classify the remote sensing data. In this case, the classification performance depends on a training data set. Using the training data set and the error back propagation algorithm, a layered neural network is trained such that the training pattern are classified with a specified accuracy. After training the neural network, some pixels are deleted from the original training data set if they are incorrectly classified and a new training data set is built up. Once training is complete, a testing data set is classified by using the trained neural network. The classification results of Landsat TM data show that this approach produces excellent results which are more realistic and noiseless compared with a conventional Bayesian method.

  • PDF

Influence of P, Ca, Zn, Mg, Fe, K, Mn, or Se in the Dietary Mineral Premix on Growth and Body Composition of Korean Rockfish (Sebastes schlegeli) (사료의 P, Ca, Zn, Mg, Fe, K, Mn과 Se이 조피볼락의 성장 및 체성분에 미치는 영향)

  • LEE Sang-Min;PARK Sung-Real
    • Korean Journal of Fisheries and Aquatic Sciences
    • /
    • v.31 no.2
    • /
    • pp.245-251
    • /
    • 1998
  • A 10-week feeding experiment was conducted to determine the influence of several minerals from dietary mineral premix on growth and body composition in juvenile Korean rockfish. Three replicate groups of fish Initially averaging 4.2 g were fed one of the ten experimental diets. Korean rockfish muscle and casein as protein sources were used in the basal diet, and deleted one of each mineral (P, Ca, Zn, Mg, Fe, K, Mn, Se or all) in the control mineral premix, Weight gain, feed efficiency and nutrient retention in fish fed the diet not containing mineral premix were significantly lower than those in fish fed other diets (P<0.01). Weight gain in fish fed the diets deleted each mineral (P, Ca, Zn, Hg, Fe, K, Mn or Se) was lower than that of control diet (P<0.01), Feed efficiency and protein retention in fish fed the diets deleted each of P, Ca, Zn or Mn were lower than those ot control diet (P<0.01). Daily feed intake and lipid retention were not affected by dietary mineral premixes ( P>0.01). Proximate analysis and mineral contents in the whole body, muscle, liver or bone of fish fed the diets deleted each mineral were not different to control diet ( P>0.01). The data obtained in this study indicate that each of the P, Ca, Zn, Mg, Fe, K, Mn or Se is essential for normal growth of Korean rockfish.

  • PDF

A Compact Divide-and-conquer Algorithm for Delaunay Triangulation with an Array-based Data Structure (배열기반 데이터 구조를 이용한 간략한 divide-and-conquer 삼각화 알고리즘)

  • Yang, Sang-Wook;Choi, Young
    • Korean Journal of Computational Design and Engineering
    • /
    • v.14 no.4
    • /
    • pp.217-224
    • /
    • 2009
  • Most divide-and-conquer implementations for Delaunay triangulation utilize quad-edge or winged-edge data structure since triangles are frequently deleted and created during the merge process. How-ever, the proposed divide-and-conquer algorithm utilizes the array based data structure that is much simpler than the quad-edge data structure and requires less memory allocation. The proposed algorithm has two important features. Firstly, the information of space partitioning is represented as a permutation vector sequence in a vertices array, thus no additional data is required for the space partitioning. The permutation vector represents adaptively divided regions in two dimensions. The two-dimensional partitioning of the space is more efficient than one-dimensional partitioning in the merge process. Secondly, there is no deletion of edge in merge process and thus no bookkeeping of complex intermediate state for topology change is necessary. The algorithm is described in a compact manner with the proposed data structures and operators so that it can be easily implemented with computational efficiency.

Optical Flow Estimation of a Fluid Based on a Physical Model

  • Kim, Jin-Woo
    • Journal of information and communication convergence engineering
    • /
    • v.7 no.4
    • /
    • pp.539-544
    • /
    • 2009
  • An estimation of 3D velocity field including occluded parts without maxing tracer to the fluid had not only never been proposed but also impossible by the conventional computer vision algorithm. In this paper, we propose a new method of three dimensional optical flow of the fluid based on physical model, where some boundary conditions are given from a priori knowledge of the flow configuration. Optical flow is obtained by minimizing the mean square errors of a basic constraint and the matching error terms with visual data using Euler equations. Here, Navier-Stokes motion equations and the differences between occluded data and observable data are employed as the basic constrains. we verify the effectiveness of our proposed method by applying our algorithm to simulated data with partly artificially deleted and recovering the lacking data. Next, applying our method to the fluid of observable surface data and the knowledge of boundary conditions, we demonstrate that 3D optical flow are obtained by proposed algorithm.

Output Analysis for Steady-State Simulation Using Lyapunov Exponent in Chaos Theory (카오스 이론의 Lyapunov 지수를 응용한 안정상태 시뮬레이션의 출력분석)

  • Lee, Young-Hae;Oh, Hyung-Sool
    • Journal of Korean Institute of Industrial Engineers
    • /
    • v.22 no.1
    • /
    • pp.65-82
    • /
    • 1996
  • This paper proposes a sequential procedure which can be used to determine a truncation point and run length to reduce or remove bias owing to artificial startup conditions in simulations aimed at estimating steady-state behavior. It is based on the idea of Lyapunov exponent in chaos theory. The performance measures considered are relative bias, coverage, estimated relative half-width of the confidence interval, and mean amount of deleted data.

  • PDF

Application of NORM to the Multiple Imputation for Multivariate Missing Data

  • Kim, Hyun-Jeong;Moon, Sung-Ho;Shin, Jae-Kyoung
    • Journal of the Korean Data and Information Science Society
    • /
    • v.13 no.2
    • /
    • pp.105-113
    • /
    • 2002
  • The statistical analysis of incomplete data sometimes requires handling of incomplete observations. Towards this end, each case with some missing values generally should be deleted, namely, resulting in only use of non-missing cases. EM algorithm(Dempster et al., 1977) which involves prediction and estimation steps is a general method among others. In this article, we use the free software NORM developed for multiple imputation, which uses DA(Data Augmentation) algorithm in its imputation, and evaluate its efficiency through a numerical example.

  • PDF