• Title/Summary/Keyword: Shared Data

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An Efficient Data Distribution Method on a Distributed Shared Memory Machine (분산공유 메모리 시스템 상에서의 효율적인 자료분산 방법)

  • Min, Ok-Gee
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.6
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    • pp.1433-1442
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    • 1996
  • Data distribution of SPMD(Single Program Multiple Data) pattern is one of main features of HPF (High Performance Fortran). This paper describes design is sues for such data distribution and its efficient execution model on TICOM IV computer, named SPAX(Scalable Parallel Architecture computer based on X-bar network). SPAX has a hierarchical clustering structure that uses distributed shared memory(DSM). In such memory structure, it cannot make a full system utilization to apply unanimously either SMDD(shared Memory Data Distribution) or DMDD(Distributed Memory Data Distribution). Here we propose another data distribution model, called DSMDD(Distributed Shared Memory Data Distribution), a data distribution model based on hierarchical masters-slaves scheme. In this model, a remote master and slaves are designated in each node, shared address scheme is used within a node and message passing scheme between nodes. In our simulation, assuming a node size in which system performance degradation is minimized,DSMDD is more effective than SMDD and DMDD. Especially,the larger number of logical processors and the less data dependency between distributed data,the better performace is obtained.

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Access-Authorizing and Privacy-Preserving Auditing with Group Dynamic for Shared Cloud Data

  • Shen, Wenting;Yu, Jia;Yang, Guangyang;Zhang, Yue;Fu, Zhangjie;Hao, Rong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.7
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    • pp.3319-3338
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    • 2016
  • Cloud storage is becoming more and more popular because of its elasticity and pay-as-you-go storage service manner. In some cloud storage scenarios, the data that are stored in the cloud may be shared by a group of users. To verify the integrity of cloud data in this kind of applications, many auditing schemes for shared cloud data have been proposed. However, all of these schemes do not consider the access authorization problem for users, which makes the revoked users still able to access the shared cloud data belonging to the group. In order to deal with this problem, we propose a novel public auditing scheme for shared cloud data in this paper. Different from previous work, in our scheme, the user in a group cannot any longer access the shared cloud data belonging to this group once this user is revoked. In addition, we propose a new random masking technique to make our scheme preserve both data privacy and identity privacy. Furthermore, our scheme supports to enroll a new user in a group and revoke an old user from a group. We analyze the security of the proposed scheme and justify its performance by concrete implementations.

Influence of Family Mealtime on the Childrens' School Adaptation - Using the Data Collected by Parents - (가족식사가 자녀의 학교적응에 미치는 영향 - 학부모 인식을 중심으로-)

  • Lee, Hyunah
    • Journal of Family Resource Management and Policy Review
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    • v.18 no.3
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    • pp.103-116
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    • 2014
  • The purpose of this study is to examine the influence of family mealtime on the childrens' school adaptation. This study uses data from the 2012 Survey on Child Education and School Involvement of Parents by the Center for Family-School Partnership Policy Research at Seoul National University. Survey data was collected from 1500 parents with school-aged children. For the data analysis, Chi sqaure test and hierarchical linear regression analyses were conducted. The results of these analyses showed that the numbers of family meals shared averaged 4.26 times per week for breakfast and 4.33 times per week for dinner. There were significant differences in the number of family meals shared together according to school level, residence area, and parent employment status, and household income. In addition, childrens' school adaptation was significantly different depending on school level, parent gender, parent education, and parent employment status. Finally, according to the hierarchical regression analyses, the number of family meals shared significantly predicted childrens' school adaptation. The greater number of family meals shared, the stronger the childrens' school adaptation. These results indicate that family mealtime has a positive effect on childrens' school adaptation. This study suggests that family mealtime is an indicator of family strength and it needs to guarantee family shared time at least to have a dinner together. This study could provide grounds for making family policy and education policy in order to guarantee family shared time.

Object-Size and Call-Site Tracing based Shared Memory Allocator for False Sharing Reduction in DSM Systems (분산 공유 메모리 시스템에서 거짓 공유를 줄이는 객체-크기 및 호출지-추적 기반 공유 메모리 할당 기법)

  • Lee, Jong-Woo;Park, Young-Ho;Yoon, Yong-Ik
    • Journal of Digital Contents Society
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    • v.9 no.1
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    • pp.77-86
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    • 2008
  • False sharing is a result of co-location of unrelated data in the same unit of memory coherency, and is one source of unnecessary overhead being of no help to keep the memory coherency in multiprocessor systems. Moreover, the damage caused by false sharing becomes large in proportion to the granularity of memory coherency. To reduce false sharing in page-based DSM systems, it is necessary to allocate unrelated data objects that have different access patterns into the separate shared pages. In this paper we propose sized and call-site tracing-based shared memory allocator, shortly SCSTallocator. SCSTallocator places each data object requested from the different call-sites into the separate shared pages, and at the same time places each data object that has different size into different shared pages. Consequently data objects that have the different call-site and different object size prohibited from being allocated to the same shared page. Our observations show that our SCSTallocator outperforms the existing dynamic shared memory allocators. By combining the two existing allocation technique, we can reduce a considerable amount of false sharing misses.

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Mutual exclusion of shared memory access in the simulation software of the midclass commuter (중형항공기 시뮬레이션 소프트웨어의 작업간 공유메모리 사용의 상호배제)

  • 이인석;이해창;이상혁
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.207-209
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    • 1996
  • The software of the midclass commuter flight simulation is running on multiprocessor/multitasking environments The software is consist of tasks which are periodically alive at a given interval. Each task communicates via shared memory. The data shared by tasks is divided by several block. Only one task, called producer, can produce data for a data block but several tasks, called consumers, can read data from the data block. Double buffer and conditional flag are used to implement a mutual exclusion which prevents the producer and consumers from accessing the same data block simultaneously.

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Visualizations of Relational Capital for Shared Vision

  • Russell, Martha G.;Still, Kaisa;Huhtamaki, Jukka;Rubens, Neil
    • World Technopolis Review
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    • v.5 no.1
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    • pp.47-60
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    • 2016
  • In today's digital non-linear global business environment, innovation initiatives are influenced by inter-organizational, political, economic, environmental, technological systems, as well as by decisions made individually by key actors in these systems. Network-based structures emerge from social linkages and collaborations among various actors, creating innovation ecosystems, complex adaptive systems in which entities co-create value. A shared vision of value co-creation allows people operating individually to arrive together at the same future. Yet, relationships are difficult to see, continually changing and challenging to manage. The Innovation Ecosystem Transformation Framework construct includes three core components to make innovation relationships visible and articulate networks of relational capital for the wellbeing, sustainability and business success of innovation ecosystems: data-driven visualizations, storytelling and shared vision. Access to data facilitates building evidence-based visualizations using relational data. This has dramatically altered the way leaders can use data-driven analysis to develop insights and provide ongoing feedback needed to orchestrate relational capital and build shared vision for high quality decisions about innovation. Enabled by a shared vision, relational capital can guide decisions that catalyze, support and sustain an ecosystemic milieu conducive to innovation for business growth.

The Factors Influencing the Use of Shared Economy-Based Mobility Services

  • KIM, Hyeong-Min
    • Journal of Distribution Science
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    • v.18 no.1
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    • pp.107-121
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    • 2020
  • Purpose: Shared mobility services are the most notable in the shared economy; however, they have yet to be activated in Korea due to various regulations and conflicts amongst stakeholders. Nevertheless, shared mobility has become an irresistible trend of the times, as it can cause a great deal of economic and environmental benefits. In this vein, the purpose of this study is to contribute to the revitalization of shared mobility services in Korea and to provide service providers with implications for developing consumer-oriented marketing strategies. Research design, data and methodology: Based on the reasons that the users do not use shared mobility service, the factors influencing the behaviors of shared mobility users are structured and analyzed in a reliable, technical and procedural manner. To this end, the theory of reasoned action (TRA) of Ajzen and Fisbbein, the initial trust model (ITM), task technology fit (TTF) and switching cost (SC) are adopted. A total of 202 questionnaires were collected from the respondents who were aware of shared mobility. Then statistical processing of the collected data used SmartPLS(v.3.2.8), a PLS-SEM (Partial Least Squares Structural Equation Modeling) analysis program. The steps of the analysis are as follows. First, a PLS-Algorithm analysis was performed to evaluate the measurement model, and a Bootstraping and Blindfolding analysis was performed to evaluate the structural model and verify the hypotheses. Second, a multi-group analysis (PLS-MGA) was conducted to further analyze the differences depending on whether or not users experienced shared mobility service. Results: The results showed that initial trusts model (ITM) and task technology fit (TTF) have positive effects on users' behaviors through the mediation of the intention to use. As opposed to the assumption, switching costs did not have negative moderating effects in relation to the intention to use and users' behaviors. The influence of IT self-efficacy was significant, depending on the prior experience to use shared mobility services. Conclusions: This study will contribute to the revitalization of domestic shared mobility services and the formulation of service providers' marketing strategies. In future studies, there is a need to explore, reconstruct, and validate factors other than the impact factors of the shared mobility services used in this research model.

A Design of the Active Web Server Supporting Synchronous Collaboration in the Web-Based Group Collaboration Systems (웹 기반 그룹 협동 시스템에서 동기화된 협동을 지원하기 위한 능동형 웹 서버 설계)

  • 허순영;배경일
    • Proceedings of the Korea Database Society Conference
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    • 1999.06a
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    • pp.95-102
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    • 1999
  • The web-based group collaborative systems are emerging as enterprise-wide information systems. Since data in group collaborative systems are apt to be shared among multiple concurrent users and modified simutaneously by them, the web-based group collaborative systems must support synchronous collaboration in order to provide users with synchronized and consistent views of shared data. This Paper proposes an active web server which can facilitate synchronous collaboration in web-based group collaborative systems. To accomplish such a goal, the active web server manages dependency relationships between shared data and web browsers referencing them and actively propagates changing details of the shared data to all web browsers referencing them. And, this paper examines usefullness and effectiveness of the active web server to apply it to the ball-bearing design example of concurrent engineering design systems. The prototype system of the active web server is developed on a commercial Object-oriented Database Management System (ODBMS) called OBJECTSTORE using the C++ programming language.

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Regional Distribution Characteristics and Meanings of Women-only Shared Housings - A Case Study of Agency-managed Shared Housings in Seoul - (여성전용 셰어하우스의 지역 분포특성과 의미에 관한 연구 - 서울의 운영사 관리형 현장 사례를 중심으로 -)

  • Kim, Nasung;Park, So-Hyun
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.35 no.4
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    • pp.3-14
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    • 2019
  • The purpose of this study is to analyze the distribution characteristics of the agency-managed shared housings in Seoul and draw the possible implications from it. The needed data for the study was obtained from an on-line shared housing portal service which provides housing information from various shared housing management agencies. By mapping out the locations and other related data into a GIS(Geographic Information System) program, this study shows that shared housings in Seoul can be sorted into four large clusters. Each cluster has a different ratio of housing types and room capacities reflecting each regional circumstance and common causes. Women-only shared housing takes up 79% of the overall shared housing ratio and, while multi-family housing type has the most count, the apartment type has a noticeably high ratio in women-only housing compared to the apartment type ratio among the other gender-specific housings. Given the high crime rate against the single-person household of young adult women, the reason for the popularity of shared-apartment housing among young women can be deduced. However, the potential tenants' practical choices and their concern for safety are not the only causes that drive the current shared housing market. The young adults in their 20's and 30's choose to live in popular places where they can engage social activities. A new tier of shared housing market has also appeared in places where young adults could not have afforded if they lived alone. Choosing where we live is no longer about just meeting the requirements for a house based on what she/he needs but also about satisfying the preferences for a living based on what she/he desires. This paper indicates that although there is an undeniable premise that 'sharing a house' revolves around the realm of housing welfare and is not a typical topic for the upper-income households, the way we live and how we choose our place to live is shifting.