• Title/Summary/Keyword: Consistency Control

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Performance Evaluation of Deferrd Locking for Maintaining Transactional Cache Consistency (트랜잭션 캐쉬 일관성을 유지하기 위한 지연 로킹 기법의 성능 평가)

  • Kwon, Hyeok-Min
    • The Transactions of the Korea Information Processing Society
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    • v.7 no.8
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    • pp.2310-2326
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    • 2000
  • Client-server DBMS based on a data-shipping model can exploit e1ient resources effectively by allowing inter-transaction caching. However, inter-transaction caching raises the need of transactional cache consistency maintenancetTCCM protocol. since each client is able to cache a portion of the database dynamically. Deferred locking(DL) is a new detection-based TCCM scheme designed on the basis of a primary copy locking algorithm. In DL, a number of lock ,ujuests and a data shipping request are combined into a single message packet to minimize the communication overhead required for consistency checking. Lsing a simulation model. the performance of the prolxlsed scheme is compared with those of two representative detection based schemes, the adaptive optimistic concurrency control and the caching two-phase locking. The performance results indicate that DL improves the overall system throughput with a reasonable transaction abort ratio over other detection - based schemes.

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INFLUENCE OF THE EVAPORATOIN OF LIQUIDS OF DENTAL CEMENTS ON THE PROPERTIES OF HARDENED CEMENTS (치과용 시멘트 용액의 증발이 경화된 시멘트의 성질에 미치는 영향)

  • Kim, Hyang-Kyung;Park, Sang-Jin
    • Restorative Dentistry and Endodontics
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    • v.22 no.1
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    • pp.156-169
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    • 1997
  • This study was designed to evaluate the influences of evaporation of liquid of dental cements by drying during long term using. Zinc phosphate cement, polycarboxylate cement, and glass ionomer cement were used, and evaluated the properties as follows; consistency, setting time, film thickness, solubility, and compressive strength according to the ADA specification. The specimens of control group were made by mixing the newly opened liquid using the powder-liquid ratio recommended by the manufacturer, and the specimens of ES groups were made by mixing the 10% evaporated liquid by drying with the powder-liquid ratio recommeded by the manufacturer, and the specimens of EM group were made by mixing the 10% evaporated liquid with the powder-liquid ratio modified for standard consistency. The following conclusions were drawn ; 1. The viscosity of mixture of all kinds of cements were increased by the evaporation of liquid, especially the viscosity of glass ionomer cement were influenced significantly. 2. The amount of liquid should be increased to get a standard consistency at the using of evaporated liquid of cement, the most significant increase of liquid amount was required on Ketac-Cem. 3. The setting times were increased at both cases of mixing of evaporated liquid with powder - liquid ratio recommended by manufacturer or modifided through consistency test. 4. At an experimental group of mixing of the evaporated liquid with powder-liquid ratio recommended by manufacturer, solubility was decreased and film thickness was increased. 5. By the result of evaporation of cement liquid, the compressive strength of polycarboxylate cement was increased slightly and it of glass ionomer cement was increased, however, by the increase of amount of liquid to be possible to manipulate the compressive strength were decreased.

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A Cache Consistency Control for B-Tree Indices in a Database Sharing System (데이타베이스 공유 시스템에서 B-트리 인덱스를 위한 캐쉬 일관성 제어)

  • On, Gyeong-O;Jo, Haeng-Rae
    • The KIPS Transactions:PartD
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    • v.8D no.5
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    • pp.593-604
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    • 2001
  • A database sharing system (DSS) refers to a system for high performance transaction processing. In the DSS, the processing nodes are coupled via a high speed network and share a common database at the disk level. Each node has a local memory and a separate copy of operating system. To reduce the number of disk accesses, the node caches data pages and index pages in its memory buffer. In general, B-tree index pages are accessed more often and thus cached at more processing nodes, than their corresponding data pages. There are also complicated operations in the B-tree such as Fetch, Fetch Next, Insertion and Deletion. Therefore, an efficient cache consistency scheme supporting high level concurrency is required. In this paper, we propose cache consistency schemes using identifiers of index pages and page_LSN of leaf page. The propose schemes can improve the system throughput by reducing the required message traffic between nodes and index re-traversal.

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Control and aggregation (II)

  • Han, Sung-Shin
    • Journal of the Korean Statistical Society
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    • v.9 no.1
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    • pp.39-60
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    • 1980
  • In the last paper, we have discussed the cannonical representatin of a dynamic linear model, on which some aggregation schemes were devised. The relationships of those aggregation schemes with dynamic properties were investigated. This paper tries to analyse she control strategy for the aggregated linear dynamic model and to investigate the dynamic properties of disaggregative model controlled by aggregated model. For the logical consistency with the last paper, all the sections and all the equations are numbered in a sequence.

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Effects of Dietary Supplemental Powerfeel on Performance and Intestinal Microflora of Broiler Chicks (파워필의 급여가 육계의 생산성 및 장내 미생물에 미치는 영향)

  • 류경선;서경석;김상호;송희종
    • Korean Journal of Poultry Science
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    • v.28 no.1
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    • pp.55-59
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    • 2001
  • The objective of these experiments gas to investigate the feeding of Powerfeel supplementation on performance and intestinal microflora of broiler chicks. Five treatments were allocated into 0, 0.025, 0.050, 0.075, 0.10% Powerfeel with four replications for five weeks. Diets contained 21.5% CP, 3,100 kcal/kg ME for the first three weeks and 19% CP, 3,100 kcal/kg ME for the rest two weeks. Weight gain, feed intake, feed conversion were weekly measured. E. coli and Salmonella were examined from cecum and ileum at the end of experiment. ND titer were also measured at five weeks old after first and booster vaccination at 14 and 21 days of age. In experiment 1, Weight gain of Powerfeef treatments was significantly higher for five weeks (P〈0.05). Feed intake increased on all Powerfeel treatments. Chicks fed Powerfeel improved feed conversion ratio(FCR) significantly compared to that of control (P〈0.05), but was not shown the consistency. In experiment 2, Weight gain and feed consumption of chicks fed Powerfeel were tended to increase, but were not statistically different from control. Powerfeel treatments showed significantly lower FCR than control(P〈0.05). The number of Salmonella and E. coli of chicks ileum fed Powerfeel were highly decreased, compared to those of control in both experiments. Powerfeel supplementation seemed to decrease the number of both Salmonella and E. coli in illeum, but was not consistency in cecum. Chicks fed Powerfeel showed significantly higher ND titer than control (P〈0.05). These results indicated that the optimum level of Powerfeel to maximize the performance of broiler chicks were estimated from 0.050 to 0.075% in broiler diets.

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Optimistic Concurrency Control Using Time-stamp Ordering in Mobile Databases (이동 데이터베이스 시스템에서 타임스탬프를 이용한 낙관적 동시성 제어 기법)

  • Kim Dae-Ho;Jeong Byeong-Soo;Lee Young-Koo
    • Journal of Internet Computing and Services
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    • v.7 no.4
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    • pp.79-90
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    • 2006
  • Data broadcasting is an efficient method for disseminating data, and is widely accepted in the database applications of mobile computing environments because of its asymmetric communication bandwidth between a server and mobile clients. This requires new types of concurrency control mechanism to support mobile transactions executed in the mobile clients, which have low-bandwidths toward the server. In this paper, we propose an OCC/DTA (Optimistic Concurrency Control with Dynamic Time-stamp Adjustment) protocol that can be efficiently adapted to mobile computing environments. The protocol reduces communication overhead by using client-side validation procedure and enhances transaction throughput by adjusting serialization order without violating transaction semantics. We show that the proposed protocol satisfies data consistency requirements, and simulate that this protocol can improve the performance of mobile transactions in data broadcasting environments.

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A Study on the automatic Lane keeping control method of a vehicle based upon a perception net (퍼셉션 넷에 기반한 차량의 자동 차선 위치 제어에 관한 연구)

  • 부광석;정문영
    • 제어로봇시스템학회:학술대회논문집
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    • 2000.10a
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    • pp.257-257
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    • 2000
  • The objective of this research is to monitor and control the vehicle motion in order to remove out the existing safety risk based upon the human-machine cooperative vehicle control. A predictive control method is proposed to control the steering wheel of the vehicle to keep the lane. Desired angle of the steering wheel to control the vehicle motion could be calculated based upon vehicle dynamics, current and estimated pose of the vehicle every sample steps. The vehicle pose and the road curvature were calculated by geometrically fusing sensor data from camera image, tachometer and steering wheel encoder though the Perception Net, where not only the state variables, but also the corresponding uncertainties were propagated in forward and backward direction in such a way to satisfy the given constraint condition, maintain consistency, reduce the uncertainties, and guarantee robustness. A series of experiments was conducted to evaluate the control performance, in which a car Like robot was utilized to quit unwanted safety problem. As the results, the robot was keeping very well a given lane with arbitrary shape at moderate speed.

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Estimating 3-D surface geometrical features on the basis of surface curvature consistency

  • Zha, H.B.;Muramatsu, S.;Nagata, T.
    • 제어로봇시스템학회:학술대회논문집
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    • 1993.10b
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    • pp.54-59
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    • 1993
  • This paper presents a method of estimating 3-D surface geometrical features that are necessary for 3-D object recognition and image interpretation. The features, such as surface needle maps and curvatures, are computed from range or intensity images. In general, the range and intensity images are prone to noises, and hence the features computed by differentiation calculi on such a noisy image are hardly applicable to industrial recognition tasks. In our approach, we try to obtain a more accurate estimate of the features by using a least-squares minimization procedure subject to local curvature consistency constraints. The algorithm is robust with respect to noises and is completely independent of the viewpoint at which the image is taken. The performance of the ajgoritlim is evaluated using both synthetic data and real intensity images.

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Effect of Reductive Bleaching on Optical Properties of Color Ledger (색지 폐지의 광학적 특성에 미치는 환원 표백의 영향)

  • 안병준;백기현
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.33 no.2
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    • pp.68-73
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    • 2001
  • This experiment was executed to clarify the optimum condition of reductive bleaching for 100% color papers. The reductive bleaching of the color paper was desirable to be done under such conditions as high temperature over $60^{\circ}C$ and high consistency within possibly short time. The FAS bleaching like the sodium hydrosulfite required oxygen-free condition. Especially, as the mixture between pulps and chemicals was favored in case of the high consistency, it was actively recommended. Therefore, it is desirable to control the dosage with the type of the dyes, the nature, the dye content, the paper compositions, and the targeting initial and final brightness.

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Parenting Behaviors Represented in Traditional Fairy Tales and Creative Stories (전래동화와 창작동화에 표현된 부모의 양육행동 연구)

  • Kim, Jungwon;Nam, Kyu
    • Korean Journal of Child Studies
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    • v.26 no.1
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    • pp.299-313
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    • 2005
  • The purpose of this study was to analyze the parenting behaviors which are represented in traditional fairy tales and creative stories. In this study the parenting behaviors of 44 traditional fairy tales and 52 creative stories for young children were analyzed according to the Korean Maternal Behavior Inventories (KMBI). The results are as follows : First, active participation, affectionate behaviors, reasonable guide, and consistency were represented more in creative stories than in traditional fairy tales and authoritarian control was represented more in traditional fairy tales than in creative stories. Second, fathers in creative stories participated more actively in their children's teaching than fathers on traditional fairy tales. Third, mothers in creative stories showed more affectionate parenting behaviors, participated more actively and showed more consistency in the relationship with their children. Fourth, the parents in traditional fairy tales showed more achievement-oriented parenting behaviors, especially in father-son relationship than others.

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