• Title/Summary/Keyword: Generate Data

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A Data-Consistency Scheme for the Distributed-Cache Storage of the Memcached System

  • Liao, Jianwei;Peng, Xiaoning
    • Journal of Computing Science and Engineering
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    • v.11 no.3
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    • pp.92-99
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    • 2017
  • Memcached, commonly used to speed up the data access in big-data and Internet-web applications, is a system software of the distributed-cache mechanism. But it is subject to the severe challenge of the loss of recently uncommitted updates in the case where the Memcached servers crash due to some reason. Although the replica scheme and the disk-log-based replay mechanism have been proposed to overcome this problem, they generate either the overhead of the replica synchronization or the persistent-storage overhead that is caused by flushing related logs. This paper proposes a scheme of backing up the write requests (i.e., set and add) on the Memcached client side, to reduce the overhead resulting from the making of disk-log records or performing the replica consistency. If the Memcached server fails, a timestamp-based recovery mechanism is then introduced to replay the write requests (buffered by relevant clients), for regaining the lost-data updates on the rebooted Memcached server, thereby meeting the data-consistency requirement. More importantly, compared with the mechanism of logging the write requests to the persistent storage of the master server and the server-replication scheme, the newly proposed approach of backing up the logs on the client side can greatly decrease the time overhead by up to 116.8% when processing the write workloads.

Study on Application of Reverse Engineering by Generation of the Free-Form Surface (자유 곡면 생성을 통한 역공학 적용에 관한 연구)

  • Hur, Sung-Min;Choi, Jae-Won;Lee, Seok-Hee
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.10
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    • pp.168-177
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models fur the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model, the generation of compatible input curves, the generation of a surface and manufacturing data like G code or STL file. A laser scanner has a great potential to get geometrical data of a model for its frost measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points including small spikes and noise. A new approach using automated surface generating algorithm is introduced to deal with problems during reverse engineering process. And the input data and the generated surface are represented in IGES format, thus can be supplied to other CAD/CAM software without any data manipulation.

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An Efficient Update for Attribute Data of the Digital Map using Building Registers : Focused on Building Numbers of the New Address (건축물대장을 이용한 수치지도 속성정보의 효율적 갱신방안 : 새주소사업의 건물번호 이용을 중심으로)

  • Kim, Jung-Ok;Kim, Ji-Young;Bae, Young-Eun;Yu, Ki-Yun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.26 no.3
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    • pp.275-284
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    • 2008
  • The digital map needs efficiently updating. Because it is a base map at each local government and several geographic information systems and that is the key to enhancing to use spatial data. We suggest the linking method of building registers to the building layers of digital map, to update attribute data of the building layers. To conduct that, it is very important that each building in two data is linked by one-to-one matching. In this paper, we generate the strategy for renewing attribute data of the building layers based on identifier by using identifier of the new address system.

Efficient Geographical Information-Based En-route Filtering Scheme in Wireless Sensor Networks

  • Yi, Chuanjun;Yang, Geng;Dai, Hua;Liu, Liang;Chen, Yunhua
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.9
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    • pp.4183-4204
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    • 2018
  • The existing en-route filtering schemes only consider some simple false data injection attacks, which results in lower safety performance. In this paper, we propose an efficient geographical information-based en-route filtering scheme (EGEFS), in which each forwarding node verifies not only the message authentication codes (MACs), but also the report identifier and the legitimacy and authenticity of locations carried in a data report. Thus, EGEFS can defend against not only the simple false data injection attacks and the replay attack, but also the collusion attack with forged locations proposed in this paper. In addition, we propose a new method for electing the center-of-stimulus (CoS) node, which can ensure that only one detecting node will be elected as the CoS node to generate one data report for an event. The simulation results show that, compared to the existing en-route filtering schemes, EGEFS has higher safety performance, because it can resist more types of false data injection attacks, and it also has higher filtering efficiency and lower energy expenditure.

The Implementation of Communication Protocol for Semiconductor Equipments with Priority of Data Traffic (데이터 트래픽의 우선 순위를 갖는 반도체 장비 통신 프로토콜 구현)

  • Kim, Doo Yong;Kim, Kiwan;Cho, Hyun Chan
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.4
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    • pp.13-18
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    • 2012
  • The semiconductor equipments generate a lot of data traffic via communication channels for the effective manufacturing processes of semiconductors and for the automation of semiconductor equipments. These data should be sent to a host computer in order to keep in a safe. The IEEE 802.11e specification gives differentiated and distributed access to a wireless communication medium with four access categories. These four access categories use different priority parameters which lead to quality of service in data traffic. In this paper, it is shown that the throughput of data depends upon the priority parameters provided by IEEE802.11e. We implement the usage of priority parameters in the SECS protocol for semiconductor equipments. It is necessary that the data from semiconductor equipments should be classified with certain priority for the effective use of our proposed method. Therefore, our scheme will contribute to improving the performance of the manufacturing processes of semiconductors.

Optimal Reservoir Operation Models for Paddy Rice Irrigation with Weather Forecasts (I) - Generating Daily Rainfall and Evaporation Data- (기상예보를 고려한 관개용 저수지의 최적 조작 모형(I) -일강수량.일증발량 자료발생-)

  • 김병진;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.1
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    • pp.63-72
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    • 1994
  • The objective of the study is to develop weather generators for daily rainfall and small pan evaporation and to test the applicability with recorded data. Daily rainfall forecasting model(DRFM) was developed that uses a first order Markov chain to describe rainfall seque- nces and applies an incomplete Gamma function to predict the amount of precipitation. Daily evaporation forecasting model(DEFM) that adopts a normal distribution function to generate the evaporation for dry and wet days was also formulated. DRFM and DEFM were tested with twenty year weather data from eleven stations using Chi-square and Kolmogorov and Smirnov goodness of fit tests. The test results showed that the generated sequences of rainfall occurrence, amount of rainfall, and pan evaporation were statistically fit to recorded data from eleven, seven, and seven stations at the 5% level of significance. Generated rainfall data from DRFM were very close in frequency distri- bution patterns to records for stations all over the country. Pan evaporation for rainy days generated were less accurate than that for dry days. And the proposed models may be used as tools to provide many mathematical models with long-term daily rainfall and small pan evaporation data. An example is an irrigation scheduling model, which will be further detailed in the paper.

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R2RML Based ShEx Schema

  • Choi, Ji-Woong
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.10
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    • pp.45-55
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    • 2018
  • R2RML is a W3C standard language that defines how to expose the relational data as RDF triples. The output from an R2RML mapping is only an RDF dataset. By definition, the dataset has no schema. The lack of schema makes the dataset in linked data portal impractical for integrating and analyzing data. To address this issue, we propose an approach for generating automatically schemas for RDF graphs populated by R2RML mappings. More precisely, we represent the schema using ShEx, which is a language for validating and describing RDF. Our approach allows to generate ShEx schemas as well as RDF datasets from R2RML mappings. Our ShEx schema can provide benefits for both data providers and ordinary users. Data providers can verify and guarantee the structural integrity of the dataset against the schema. Users can write SPARQL queries efficiently by referring to the schema. In this paper, we describe data structures and algorithms of the system to derive ShEx documents from R2RML documents and presents a brief demonstration regarding its proper use.

ShEx Schema Generator for RDF Graphs Created by Direct Mapping

  • Choi, Ji-Woong
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.10
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    • pp.33-43
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    • 2018
  • In this paper, we propose a method to automatically generate the description of an RDF graph structure. The description is expressed in Shape Expression Language (ShEx), which is developed by W3C and provides the syntax for describing the structure of RDF data. The RDF graphs to which this method can be applied are limited to those generated by the direct mapping, which is an algorithm for transforming relational data into RDF by W3C. A relational database consists of its schema including integrity constraints and its instance data. While the instance data can have been published in RDF by some standard methods such as the direct mapping, the translation of the schema has been missing so far. Unlike the users on relational databases, the ones on RDF datasets were forced to write repeated vague SPARQL queries over the datasets to acquire the exact results. This is because the schema for RDF data has not been provided to the users. The ShEx documents generated by our method can be referred as the schema on writing SPARQL queries. They also can validate data on RDF graph update operations with ShEx validators. In other words, they can work as the integrity constraints in relational databases.

Bio-vector Generation Framework for Smart Healthcare

  • Shin, Yoon-Hwan
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.1
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    • pp.107-113
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    • 2016
  • In this paper, by managing the biometric data is changed with the passage of time, a systematic and scientifically propose a framework to increase the bio-vector generation efficiency of the smart health care. Increasing the development of human life as a medicine and has emerged smart health care according to this. Organic and efficient health management becomes possible to generate a vector when the biological domain to the wireless communication infrastructure based on the measurement of the health status and to take action in accordance with the change of the physical condition. In this paper, we propose a framework to create a bio-vector that contains information about the current state of health of the person. In the proposed framework, Bio vectors may be generated by collecting the biometric data such as blood pressure, pulse, body weight. Biometric data is the raw data from the bio-vector. The scope of the primary data can be set to active. As the collecting biometric data from multiple items of the bio-recognition vectors may increase. The resulting bio-vector is used as a measure to determine the current health of the person. Bio-vector generating the proposed framework, it can aid in the efficiency and systemic health of healthcare for the individual.

Design and Implementation of Data Protocol for Environmental Information Monitoring in Wired and Wireless Networks (유무선 통신망에서 운용 가능한 환경정보 모니터링 데이터 프로토콜 설계 및 구현)

  • Ye, Seoung-Bin;Ceong, Hee-Taek;Han, Soon-Hee
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.2
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    • pp.312-320
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    • 2010
  • Most online monitoring systems of running currently based on the wired network and local area wireless network generate an increase of administrative costs such as synchronization of data protocol conversion, flexible operation of measurement devices and maintenance. To solve this problem, this paper proposes the SMS data transmission protocol which allows multiple data collecting device to manage effectively including implementation method of cdma-based environmental information monitoring system. Also this paper shows operational safety of the proposed protocol and analyzes efficiency of data transfer and operating using SMS.