• 제목/요약/키워드: pattern blocks

검색결과 225건 처리시간 0.027초

이종재료의 압축에 의한 경계면의 성장거동에 관한 수치해석 (Numerical Analysis for Growth Behavior of Sawtoothed Interface by the compression of Dissimilar Blocks Twinned)

  • 정태훈
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.233-236
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    • 1999
  • In this paper. Compression in the case where dissimilar blocks are twinned variously are carried out in the condition of lubricated interface. The degree of growth is experimentally investigated. Moreover, numerical simulations are carried out by the elastic-plastic FEM for the case of the dissimilar blocks with the initial sawtooth angle of $60^{\circ}$ . The dissimilar blocks are twinned, larger difference between material properties leads smaller growth, and the degreased interface leads smaller growth than that in the lubricated one. Furthermore, by the simulation of compression where dissimilar blocks are twinned, it is confirmed that the tendency of the general deformation pattern is very similar to the experiment.

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구성놀이 질과 문제해결력 간의 관계 (Relations Between Qualities of Constructive Play and Problem Solving)

  • 한석실;박주희
    • 아동학회지
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    • 제28권5호
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    • pp.143-159
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    • 2007
  • This study examined the relation between the quality of constructive play and convergent and divergent problem solving. The subjects were 48 five-year-old children. Unit blocks were used to test the quality level of constructive play; a 40 piece puzzle and pattern blocks were used to test convergent problem solving; the pattern blocks also were used to test divergent problem solving. Children's block play was videotaped and pictures were taken of constructions made by children. Data were analyzed by correlation and stepwise multiple regression. Results showed statistically significant correlations between the quality of constructive play and convergent and divergent problem solving. Among the sub variables of constructive play, social play patterns affected convergent problem solving; diversity affected divergent problem solving.

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대형 교환 시스템의 소프트웨어 신뢰도 성장 (An Evolution of Reliability of large Scale Software of a Switching System)

  • 이재기;신상권;남상식;박권철
    • 전자통신동향분석
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    • 제14권4호통권58호
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    • pp.1-9
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    • 1999
  • In this paper, we summarize the lessons learned from the applications of the software reliability engineering to a large-scale software project. The considered software is the software system of the TDX-10 ISDN switching system. The considered software consists of many components, called functional blocks. These functional blocks serve as the unit of coding and test. The software is continuing to be developed by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components to software reliability and with the analysis of the reliability evolution. We analyze the static characteristics of the software related to software reliability using failure data collected during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of software of the TDX-10 ISDN system, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto (G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources for a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

An Evolution of Software Reliability in a Large Scale Switching System: using the software

  • Lee, Jae-Ki;Nam, Sang-Sik;Kim, Chang-Bong
    • 한국통신학회논문지
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    • 제29권4A호
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    • pp.399-414
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    • 2004
  • In this paper, an evolution of software reliability engineering in a large-scale software project is summarized. The considered software consists of many components, called functional blocks in software of switching system. These functional blocks are served as the unit of coding and test, and the software is continuously updated by adding new functional blocks. We are mainly concerned with the analysis of the effects of these software components in software reliability and reliability evolution. We analyze the static characteristics of the software related to software reliability using collected failure data during system test. We also discussed a pattern which represents a local and global growth of the software reliability as version evolves. To find the pattern of system software, we apply the S-shaped model to a collection of failure data sets of each evolutionary version and the Goel-Okumoto(G-O) model to a grouped overall failure data set. We expect this pattern analysis will be helpful to plan and manage necessary human/resources fur a new similar software project which is developed under the same developing circumstances by estimating the total software failures with respect to its size and time.

육방정 페라이트의 결정과 Block 구조 (Crystal and Block Structures of Hexagonal Ferrites)

  • 신형섭
    • 한국세라믹학회지
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    • 제49권3호
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    • pp.205-215
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    • 2012
  • It has been studied the crystal and block structures of the hexagonal ferrites with M, W, Y and Z types prepared by various coprecipitation-oxidation method. The structures have been refined with a Rietveld analysis of the powder X-ray diffraction pattern with high precision ($R_{WP}$ <0.09, $R_I$ <0.03). The density difference between the S-blocks was proportioned to the cobalt contents in hexagonal ferrites, but that between the R or T-blocks was relatively small. Compared with the blocks and cation-oxygen polyhedra in BaM ($BaFe_{12}O_{19}$), those were bulky to the normal direction for the c-axis in $Co_2W$ ($BaCo_2Fe_{16}O_{27}$) and to the parallel direction for the c-axis in $Co_2Y$ ($Ba_2Co_2Fe_{12}O_{22}$) and $Co_2Z$ ($Ba_3Co_2Fe_{24}O_{41}$). The S-blocks of $Co_2W$, $Co_2Y$, and $Co_2Z$ were unstable and distorted. Because the T-block of $Co_2Z$ was unstable, the T-block was decomposed into the Ba-rich phase and $Co_2W$ at high temperatures above $1200^{\circ}C$. A standard powder X-ray diffraction pattern for $Co_2Z$ was proposed as well.

톱니형상면의 압축에 의한 성장거동 시뮬레이션 (Simulation of Growth Behavior of Sawtoothed Interface by the compression)

  • 정태훈
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2002년도 추계학술대회 논문집
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    • pp.90-94
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    • 2002
  • In this paper, Compression in the case where dissimilar blocks are twinned variously are carried out in the condition of lubricated interface. The degree of growth is experimentally investigated. Moreover, numerical simulations are carried out by the elastic-plastic FEM for the case of the dissimilar blocks with the initial sawtooth angle of 60。. The dissimilar blocks are twinned, larger difference between material properties leads smaller growth, and the degreased interface leads smaller growth than that in the lubricated one. Furthermore, by the simulation of compression where dissimilar blocks are twinned, it is confirmed that the tendency of the general deformation pattern is very similar to the experiment.

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Spatial Scheduling in Shipbuilding Industry

  • Duck Young Yoon;Varghese Ranjan;Koo Chung Kon
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.106-110
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    • 2004
  • In any large heavy industry like that of ship building, there exist a lot of complications for the arrangement of building blocks optimally for the minimal space consumption. The major problem arises at yard because of laxity in space for arranging the building blocks of ship under construction. A standardized erection sequence diagram is generally available to provide the prioritised erection sequence. This erection sequence diagram serves as the frame work. In order to make a timely erection of the blocks a post plan has to be developed so that the blocks lie in the nearest possible vicinity of the material handling devices while keeping the priority of erection. Therefore, the blocks are arranged in the pre-erection area. This kind of readiness of blocks leads to a very complex problem of space. This arises due to the least available space leading to an urgent need of an availability of intelligent spatial schedule without compromising the rate of production. There exists two critical problems ahead namely, the spatial occupation layout of pre-erection area and the emptying pattern in the spatial vicinity. The block shape is assumed be rectangular. The related input data's are the dates of erection (earliest as well as the latest), geometrical parameters of block available on pre-erection area, slack time and the like.

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구성놀이 전개 유형, 연령, 성별에 따른 구성놀이 질 및 가작화에서의 차이 (Proceeding patterns of block play, and differences on block play's quality and symbolic play' pretending elements)

  • 한석실;박주희
    • 한국생활과학회지
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    • 제23권1호
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    • pp.31-46
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    • 2014
  • This study investigated the proceeding patterns of constructive play with lego blocks, and the differences on the quality of constructive play and symbolic play's pretending elements. The subjects were 132 children at child care centers and kindergarten: 64 three-year-olds (36 boy, 28 girl) and 68 five-year-olds (32 boy, 36 girl). The study found three proceeding patterns in the constructive lego play. First, children engaged in constructive and symbolic play simultaneously, or they switched back and forth between symbolic and constructive play. This pattern was termed as "constructive and symbolic play simultaneously or alternatively"(type 3), and it was occurred most frequently. Secondly, children focused only on constructing structures. This pattern was termed as "constructive play only"(type 1), Thirdly, children engaged in symbolic play only after they completed building some structures. This pattern was named "symbolic play after constructive play"(type 2). The findings also indicated that children who were categorized as type 1 and 2 showed higher quality of constructive play and longer duration in play than children as type 3. Five-year-old children sustained play longer and showed higher quality in terms of elaboration, imagination, and variety (number of blocks, shape of blocks). Furthermore, children as type 3 showed a higher level of imaginative play than children as type 1 and 2, especially in terms of role, objet, and context of projection.

Spatio-temporal Distribution Pattern of New Biotypes of Weedy Rice (Oryza sativa L.) in Selangor North-West Project, Malaysia

  • Baki, B.B.;M.M., Shakirin
    • 한국잡초학회지
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    • 제30권2호
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    • pp.68-83
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    • 2010
  • Weedy rice (Oryza sativa L.) occurred sympatrically with other weeds and the rice crop in Malaysian rice granaries. We conducted field surveys in 2006-2008 seasons in 7 farm blocks of Selangor's North West Project, Malaysia to enlist the new biotypes of weedy rice (NBWR) and assess their spatio-temporal pattern of distribution based on quantitative and dispersion indices. No less than 16 accessions of NBWR were identified based on their special traits, viz. panicle type, pericarp colour, presence or absence of awn, seed type and degree of grain shattering. The NBWR accessions exhibited a combination of morphological traits from open panicle, grain with awns, red pericarp, short grain type, and degrees of grain shattering. Others mimic commercial rices with close panicle, awnless grains, white pericarp, long or short grain-type. Invariably, the NBWRs mimic and stand as tall as cultivated rice namely MR219, MR220, or MR235 and these NBWR accessions stand among equals morphologically vis-a-vis the commercial rice varieties. Most accessions displayed varying degrees of grain shattering in excess of 50%, except Acc9 and Acc12. The seasonal dynamics of on the prevalence of dominant NBWR accessions were also displaying significant differences among farm blocks. While Bagan Terap farm block, for example, did not record any measurable changes in the dominant NBWR accessions over seasons, the Sungai Leman farm block recorded measurable season-mediated changes in the dominant NBWR accessions. Sungai Leman started with NBWR Acc3, Acc4, Acc5, Acc7, Acc8, and Acc12 in season 1 of 2006/2007, but no measurable records of Acc3 and Acc5 were shown in season 2 of 2007. In season 3 of 2007/2008, only Acc8 and Acc12 prevailed in the farm block. In Sawah Sempadan farm block, season 3 of 2007/2008 showed much reduced prevalence of NBWRs leaving only Acc8 and Acc12. Most accessions registered clump or under-dispersed spatial distribution pattern based on quantitative indices: variance-to-mean ratio (VMR) and Lloyd's patchiness values. The dynamics on the extent of infestation and prevalence of dominant NBWR accessions registered both season- and farm-block mediated differences. Most accessions showed VMR >1 thus indicative of having a clump or clustered spatial distribution, as exemplified by Acc3, Acc4, Acc7, Acc8 and Acc12 in all farm blocks throughout three seasons. Some accessions have either random or uniform distribution in a few farm blocks. The Acc8 has the highest population counts based on important value index, followed by Acc12, and both were the most dominant accession while Sawah Sempadan was the worst farm block infested by NBWR compared to other farm blocks. These results were discussed in relation with the current agronomic and weed management practices, water availability and extension services in the granary.

An Improved Secure Semi-fragile Watermarking Based on LBP and Arnold Transform

  • Zhang, Heng;Wang, Chengyou;Zhou, Xiao
    • Journal of Information Processing Systems
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    • 제13권5호
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    • pp.1382-1396
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    • 2017
  • In this paper, we analyze a recently proposed semi-fragile watermarking scheme based on local binary pattern (LBP) operators, and note that it has a fundamental flaw in the design. In this work, a binary watermark is embedded into image blocks by modifying the neighborhood pixels according to the LBP pattern. However, different image blocks might have the same LBP pattern, which can lead to false detection in watermark extraction process. In other words, one can modify the host image intentionally without affecting its watermark message. In addition, there is no encryption process before watermark embedding, which brings another potential security problem. To illustrate its weakness, two special copy-paste attacks are proposed in this paper, and several experiments are conducted to prove the effectiveness of these attacks. To solve these problems, an improved semi-fragile watermarking based on LBP operators is presented. In watermark embedding process, the central pixel value of each block is taken into account and Arnold transform is adopted to guarantee the security of watermark. Experimental results show that the improved watermarking scheme can overcome the above defects and locate the tampered region effectively.