• Title/Summary/Keyword: distributed system concept

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A Study on Analysis and user-friendly Improvement Plan for Urban Planning Information System (수요자 중심의 도시계획정보체계 개선방안)

  • Lee, Se-won;Kang, Ji-Hun;Kim, Heung-Cheol
    • Journal of Cadastre & Land InformatiX
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    • v.48 no.2
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    • pp.153-170
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    • 2018
  • The purpose of this study is to diagnose problems by analyzing the status of system and user in order to activate the Urban Planning Information System(UPIS). The UPIS has been distributed to all local governments through pilot and expansion projects since 2003 to utilize spatial information in urban planning and administration. The original purpose was to use GIS to support planning and to support scientific decision making, but now the main task is to designate and manage zoning districts related to land use. Therefore, the UPIS is responsible for the production (preparation procedure) and management of the local district information for use in the Korea land use information system, which is an upper concept defined by the law, but it is evaluated that its identity is ambiguous and utilization rate is low. This study is conducted to investigate the four aspects (business process, database, system, citizen service) of UPIS, and suggest concrete improvement measures. To summarize, each individual system exists in the Korea land use information system, but they all share similar data and have a linked work flow. Therefore, we suggested that the DB current plan should be established to improve the reliability of data and to redefine the business process around the UPIS.

Implementation of a DB-Based Virtual File System for Lightweight IoT Clouds (경량 사물 인터넷 클라우드를 위한 DB 기반 가상 파일 시스템 구현)

  • Lee, Hyung-Bong;Kwon, Ki-Hyeon
    • KIPS Transactions on Computer and Communication Systems
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    • v.3 no.10
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    • pp.311-322
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    • 2014
  • IoT(Internet of Things) is a concept of connected internet pursuing direct access to devices or sensors in fused environment of personal, industrial and public area. In IoT environment, it is possible to access realtime data, and the data format and topology of devices are diverse. Also, there are bidirectional communications between users and devices to control actuators in IoT. In this point, IoT is different from the conventional internet in which data are produced by human desktops and gathered in server systems by way of one-sided simple internet communications. For the cloud or portal service of IoT, there should be a file management framework supporting systematic naming service and unified data access interface encompassing the variety of IoT things. This paper implements a DB-based virtual file system maintaining attributes of IoT things in a UNIX-styled file system view. Users who logged in the virtual shell are able to explore IoT things by navigating the virtual file system, and able to access IoT things directly via UNIX-styled file I O APIs. The implemented virtual file system is lightweight and flexible because it maintains only directory structure and descriptors for the distributed IoT things. The result of a test for the virtual shell primitives such as mkdir() or chdir() shows the smooth functionality of the virtual file system, Also, the exploring performance of the file system is better than that of Window file system in case of adopting a simple directory cache mechanism.

Implementation of a Web-based Hybrid Engineering Experiment System for Enhancing Learning Efficiency (학습효율 향상을 위한 웹기반 하이브리드 공학실험시스템 구현)

  • Kim, Dong-Sik;Choi, Kwan-Sun;Lee, Sun-Heum
    • Journal of Engineering Education Research
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    • v.10 no.3
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    • pp.79-92
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    • 2007
  • To enhance the excellence, effectiveness and economical efficiency in the learning process, we implement a hybrid educational system for engineering experiments where web-based virtual laboratory systems and distance education systems are properly integrated. In the first stage, we designed client/server distributed environment and developed web-based virtual laboratory systems for digital systems and electrical/electronic circuit experiments. The proposed virtual laboratory systems are composed of four important sessions and their management system: concept learning session, virtual experiment session, assessment session. With the aid of the management system every session is organically tied up together to achieve maximum learning efficiency. In the second stage, we have implemented efficient and cost-effective distant laboratory systems for practicing electric/electronic circuits, which can be used to eliminate the lack of reality occurred during virtual laboratory session. The use of simple and user-friendly design allows a large number of people to access our distant laboratory systems easily. Thus, self-guided advanced training is available even if a lot of expensive equipment will not be provided in the on-campus laboratories. The proposed virtual/distant laboratory systems can be used in stand-alone fashion, but to enhance learning efficiency we integrated them and developed a hybrid educational system for engineering experiments. Our hybrid education system provides the learners with interactive learning environment and a new approach for the delivery of engineering experiments.

Computer Vision-based Continuous Large-scale Site Monitoring System through Edge Computing and Small-Object Detection

  • Kim, Yeonjoo;Kim, Siyeon;Hwang, Sungjoo;Hong, Seok Hwan
    • International conference on construction engineering and project management
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    • 2022.06a
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    • pp.1243-1244
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    • 2022
  • In recent years, the growing interest in off-site construction has led to factories scaling up their manufacturing and production processes in the construction sector. Consequently, continuous large-scale site monitoring in low-variability environments, such as prefabricated components production plants (precast concrete production), has gained increasing importance. Although many studies on computer vision-based site monitoring have been conducted, challenges for deploying this technology for large-scale field applications still remain. One of the issues is collecting and transmitting vast amounts of video data. Continuous site monitoring systems are based on real-time video data collection and analysis, which requires excessive computational resources and network traffic. In addition, it is difficult to integrate various object information with different sizes and scales into a single scene. Various sizes and types of objects (e.g., workers, heavy equipment, and materials) exist in a plant production environment, and these objects should be detected simultaneously for effective site monitoring. However, with the existing object detection algorithms, it is difficult to simultaneously detect objects with significant differences in size because collecting and training massive amounts of object image data with various scales is necessary. This study thus developed a large-scale site monitoring system using edge computing and a small-object detection system to solve these problems. Edge computing is a distributed information technology architecture wherein the image or video data is processed near the originating source, not on a centralized server or cloud. By inferring information from the AI computing module equipped with CCTVs and communicating only the processed information with the server, it is possible to reduce excessive network traffic. Small-object detection is an innovative method to detect different-sized objects by cropping the raw image and setting the appropriate number of rows and columns for image splitting based on the target object size. This enables the detection of small objects from cropped and magnified images. The detected small objects can then be expressed in the original image. In the inference process, this study used the YOLO-v5 algorithm, known for its fast processing speed and widely used for real-time object detection. This method could effectively detect large and even small objects that were difficult to detect with the existing object detection algorithms. When the large-scale site monitoring system was tested, it performed well in detecting small objects, such as workers in a large-scale view of construction sites, which were inaccurately detected by the existing algorithms. Our next goal is to incorporate various safety monitoring and risk analysis algorithms into this system, such as collision risk estimation, based on the time-to-collision concept, enabling the optimization of safety routes by accumulating workers' paths and inferring the risky areas based on workers' trajectory patterns. Through such developments, this continuous large-scale site monitoring system can guide a construction plant's safety management system more effectively.

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The Effect of Government's Fairness as the Entrepreneur's Satisfactions & Managerial Performance: Focusing on the Differences between Start-up Companies' Growth Stage (정부의 창업지원 공정성이 만족도 및 경영성과에 미치는 영향: 창업기업의 성장단계별 차이를 중심으로)

  • Jang, Younghye;Lee, Jeonghye;Kim, Pansoo
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.15 no.4
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    • pp.109-120
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    • 2020
  • This study examines how the government's fairness in entrepreneurship support affects satisfaction and management performance, and examines whether these influences are different for each growth stage of start-up companies. For this study, data were collected for start-up companies that received government support for start-up within the past 5 years. Total 611 copies of the data were used in this study. The collected data were analyzed using SPSS and AMOS. The fairness used in this study was divided into three types, procedural fairness, interactive fairness, and distributed fairness. The effect of the three fairness on the satisfaction of start-up support project was analyzed. In addition, the effect of business support satisfaction on business performance was analyzed, where the business performance was evaluated by the questioner's satisfaction with their business. The start-up phase was divided into the start phase, early growth phase, stagnant phase, and high-level growth phase, and the moderating effect between the fairness and satisfaction of the government-supported projects by start-up phase was analyzed. As a result, it was found that every concept of fairness had a positive (+) effect on the satisfaction of the entrepreneurship support project, and the satisfaction of the entrepreneurship support project had a positive (+) effect on the management performance. The concept of procedural fairness in the start phase, procedural fairness in the early growth phase, interactive fairness, and the concept of all fairness in the stagnant phase influenced the satisfaction of the start-up support project. In this study, the fairness and effect of government-supported projects affecting the management performance of start-ups were identified by growth phase of start-ups. The results of these studies will help build a systematic system for entrepreneurship support and for start-ups, it will also greatly contribute to finding differentiated growth plans by growth stages of start-up companies.

An Extensible Transaction Model for Real-Time Data Processing (실시간 데이타 처리를 위한 확장 가능한 트랜잭션 모델에 관한 연구)

  • 문승진
    • Journal of Internet Computing and Services
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    • v.1 no.2
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    • pp.11-18
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    • 2000
  • In this paper we present a new extensible model based upon the concept of subtransactions in real-time transaction systems. The nested transaction model originally proposed by J. Moss is extended for real-time uniprocessor transaction systems by adding explicit timing constraints. Based upon the model, an integrated concurrency control and scheduling algorithm is developed, that not only guarantees timing constraints of a set of real-time transactions but also maintains consistency of the database. The algorithm is based on the priority ceiling protocol of Sha et al. We prove that the Real-Time Nested Priority Ceiling Protocol prevents unbounded blocking and deadlock, and maintains the serializability of a set of real-time transactions. We use the upper bound on the duration that a transaction can be blocked to show that it is possible to analyze the schedulability of a transaction set using rate-monotonic priority assignment. This work is viewed as a step toward multiprocessor and distributed real-time nested transaction systems. Also, it is possible to be extended to include the real-time multimedia transactions in the emerging web-based database application areas.

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Recent Advancements of Treatment for Leptomeningeal Carcinomatosis

  • Gwak, Ho-Shin;Lee, Sang Hyun;Park, Weon Seo;Shin, Sang Hoon;Yoo, Heon;Lee, Seung Hoon
    • Journal of Korean Neurosurgical Society
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    • v.58 no.1
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    • pp.1-8
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    • 2015
  • Treatment of Leptomeningeal carcinomatosis (LMC) from solid cancers has not advanced noticeably since the introduction of intra-cerebrospinal fluid (CSF) chemotherapy in the 1970's. The marginal survival benefit and difficulty of intrathecal chemotherapy injection has hindered its wide spread use. Even after the introduction of intraventricular chemotherapy with Ommaya reservoir, frequent development of CSF flow disturbance, manifested as increased intracranial pressure (ICP), made injected drug to be distributed unevenly and thus, the therapy became ineffective. Systemic chemotherapy for LMC has been limited as effective CSF concentration can hardly be achieved except high dose methotrexate (MTX) intravenous administration. However, the introduction of small molecular weight target inhibitors for primary cancer treatment has changed the old concept of 'blood-brain barrier' as the ultimate barrier to systemically administered drugs. Conventional oral administration achieves an effective concentration at the nanomolar level. Furthermore, many studies report that a combined treatment of target inhibitor and intra-CSF chemotherapy significantly prolongs patient survival. Ventriculolumbar perfusion (VLP) chemotherapy has sought to increase drug delivery to the subarachnoid CSF space even in patients with disturbed CSF flow. Recently authors performed phase 1 and 2 clinical trial of VLP chemotherapy with MTX, and 3/4th of patients with increased ICP got controlled ICP and the survival was prolonged. Further trials are required with newly available drugs for CSF chemotherapy. Additionally, new LMC biologic/pharmacodynamic markers for early diagnosis and monitoring of the treatment response are to be identified with the help of advanced molecular biology techniques.

Design and Implementation of Clusters with Single Process Space (단일 프로세스 공간을 제공하는 클러스터 시스템의 설계 및 구현)

  • Park, Min;Lee, Daewoo;Park, Dong-Gun;JungLok yu;Maeng, Seung-Ryoul
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.04a
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    • pp.16-18
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    • 2004
  • Single system image(SSI) have been the mainstay high-performance computing for many years. SSI requires the integration and aggregation of all types of resources in a cluster to present a single interface to users. In this paper, we describe a cluster computing architecture with the concept of single process space(SPS) where all processes share a uniform process identification scheme. With SPS, a process on any node can create child process on the same or different node or communicate with any other process on a remote node, as if they are on a single node. For this purpose, SPS is built with the support of unique cluster-wide pid, signal forwarding, and remote fork. We propose a novel design of SPS cluster which addresses the scalability and flexibility problem of traditional clusterwidely unique pid implementation by using blocked pid assignment. We have implemented this new design of SPS cluster, and we demonstrate its performance by comparing it to Beowulf distributed process space. Benchmark performance results show that our design of SPS cluster realized both scalability and flexibility that are essential to building SPS cluster.

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Design of a Large-scale Task Dispatching & Processing System based on Hadoop (하둡 기반 대규모 작업 배치 및 처리 기술 설계)

  • Kim, Jik-Soo;Cao, Nguyen;Kim, Seoyoung;Hwang, Soonwook
    • Journal of KIISE
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    • v.43 no.6
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    • pp.613-620
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    • 2016
  • This paper presents a MOHA(Many-Task Computing on Hadoop) framework which aims to effectively apply the Many-Task Computing(MTC) technologies originally developed for high-performance processing of many tasks, to the existing Big Data processing platform Hadoop. We present basic concepts, motivation, preliminary results of PoC based on distributed message queue, and future research directions of MOHA. MTC applications may have relatively low I/O requirements per task. However, a very large number of tasks should be efficiently processed with potentially heavy inter-communications based on files. Therefore, MTC applications can show another pattern of data-intensive workloads compared to existing Hadoop applications, typically based on relatively large data block sizes. Through an effective convergence of MTC and Big Data technologies, we can introduce a new MOHA framework which can support the large-scale scientific applications along with the Hadoop ecosystem, which is evolving into a multi-application platform.

Update Propagation of Replicated Spatial Data using New Locking Techniques in Distributed Geographic Information System (분산된 지리정보시스템에서 새로운 잠금기법을 이용한 중복된 공간 데이터의 변경 전파)

  • Choe, Jin-O;Hong, Bong-Hui
    • Journal of KIISE:Software and Applications
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    • v.26 no.9
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    • pp.1061-1072
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    • 1999
  • 한 개 이상의 사이트에 공간 데이타가 중복 저장된 분산 공간 DB에서, 동시에 수행될 수 있는 긴 트랜잭션의 변경은 일관성 제어를 위해 다른 사이트에 전파되어야 한다. 이때 같은 영역의 공간 데이타를 서로 다른 사이트에서 동시에 변경할 경우, 변경 상충 문제가 발생하거나 잠금 기법에 의한 오랜 대기 시간이 초래되는 문제가 있다. 또한 공간 객체는 잠금의 대상이 아닌 공간 관련성에 의한 종속성을 가진다.이 논문은 긴 트랜잭션으로 중복된 공간 데이타를 변경할 경우 중복 제어를 위한 변경 전파와 동시성 제어 문제를 다룬다. 중복된 공간 데이타의 변경 병렬성을 향상시키기 위해 영역 잠금 및 SR-bound WRITE 잠금 기법을 제시한다. 한 사이트에서 수정하는 객체들과 다른 사이트에서 수정하는 객체들 사이에 공간 관련성에 의한 종속성이 없을 경우 병렬 수정을 허용하도록 제어하며, 공간 관련성에 의한 종속성이 있을 경우 SR-based 2PC라 불리는, 확장된 2단계 완료 프로토콜로 협동작업을 수행해서 변경 상충을 해결하는 새로운 중복 제어 기법을 설계하고 구현한다.Abstract The update of a long transaction should be propagated to the other sites for consistency control, when spatial database are replicated at multiple sites to achieve availability, reliability, and performance. When the replicated spatial data are updated at the same time, the update of one site would be conflicted with the other or a user would not be able to access the replicated spatial data under the control of locking. Two spatial objects having spatial relationships should be cooperatively updated even if there are no conflicts of locking for them.This paper deals with the issues of concurrency control and update propagation of replicated spatial data. We present the concept of region lock and SR-bound WRITE lock for enhancing the parallelism of updating the replicated spatial data. If there are no spatial relationships between one site's objets and the other's objects, parallel update would be allowed. Concurrent update of two spatial objects having spatial relationships should be propagated and cooperated by using an extended two-phase commit protocol, called spatial relationship-based 2PC.