• 한국정보전자통신기술학회논문지
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• 제11권1호
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• pp.26-33
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• 2018

A web application running on the Internet is causing many difficulties for a program developer, and it requires to process multiple sessions at the same time due to the occurrence of excessive traffic. Web applications should be able to process concurrent requests efficiently and in real time. Node.js is a single-threaded server-side JavaScript environment implemented in C and C ++ as one of the latest frameworks to implement event models across the entire stack. Nodes implement JavaScript quickly and robust to achieve the best performance using a JavaScript V8 engine developed by Google. In this paper, it will be explained the operation principle of Node.js, which is a lightweight real-time web server that can be implemented in JavaScript for real-time responsive web applications. In addition, this application was practically implemented through automatic alignment system for group scheduling to demonstrate event-based real-time response web processing.

• 한국정밀공학회지
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• 제19권12호
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• pp.70-77
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• 2002

Necessity of the tole-operation has been increased in many fields. Since the Internet is inexpensive and available all over the world, it is a strong candidate for the transmission media of the tole-operation. However, the Internet has random time delays that may cause instability in the system especially if the tole -operation is bilateral. In the past few years many attempts have been made to overcome the random time delay, So far, they are still insufficient in terms of performance. The ‘Variable holding time’ is introduced to improve the performance of the ‘Event based tole-operation’ which controls a system with a non-time action reference. By holding each event for proper time, the system can quickly respond and be stabilized. The proper holding time should be selected based on the characteristics of the task that the system performs. The factors that reflect those characteristics are investigated. The fuzzy logic is employed to obtain the proper holding time for each event while the tole-operation system is in operation. The experimental results presented in this paper verify effectiveness of the proposed method.

• 한국언어정보학회지:언어와정보
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• 제7권2호
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• pp.139-161
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• 2003

The progressive in English is taken to be an operator which takes a non-stative predicate and returns a predicate which denotes a process with a temporal frame around some definite time or event. When, it is combined with a predicate which has a culmination in the event, the sentence means that the culmination has not come yet. So the event denoted by the base predicate is not true at the current time. On the other hand, when it is combined with a predicate which has no culmination in the event, the event denoted by the base predicate is taken to be true. In this paper, this is explained by the semantics of the progressive based on the notion of contributiveness. I propose that a progressive sentence is verified by some subevents which are contributive to the current situation and the progress of the event beyond the threshold level of the event denoted by the base predicate. A sub-situation is contributive if the addition of it to the previous situation is more likely to lead to the whole situation than the previous situation.

• The Journal of Asian Finance, Economics and Business
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• 제7권5호
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• pp.9-18
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• 2020

The research paper examines the influence of elections on the stock market. The study analyses whether the market reaction would be the same when a party wins and comes to power for the second consecutive time. The study employs Market Model Event study methodology. The sample period taken for the study is 2014 to 2019. A sample of 31 companies listed in Bombay Stock Exchange is selected at random for the purpose of the study. For the elections held in 2014, an event window of 82 days was taken with 39 days prior to the event and 42 days post event. The event (t0) being the declaration of the election results. For the elections held in 2019 an event window of 83 days was taken with 41 days prior to the event and 41 days post event. The results indicate that the market reacts positively with significantly positive Average Abnormal Returns. The findings of the study reveal that the impact on the market is not the same between any two elections even when the same party comes to power for the second time. The semi-strong form of efficient market hypothesis holds true in the context of emerging markets like India.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2010년도 한국컴퓨터종합학술대회논문집 Vol.37 No.1(D)
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• pp.360-365
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• 2010

In this paper, we present a distributed algorithm for detecting dynamic event regions in wireless sensor network with the consideration on energy saving. Our model is that the sensing field is monitored by a large number of randomly distributed sensors with low-power battery and limited functionality, and that the event region is dynamic with motion or changing the shape. At any time that the event happens, we need some sensors awake to detect it and to wake up its k-hop neighbors to detect further events. Scheduling for the network to save the total power-cost or to maximize the monitoring time has been studied extensively. Our scheme is that some predetermined sensors, called critical sensors are awake all the time and when the event is detected by a critical sensor the sensor broadcasts to the neighbors to check their sensing area. Then the neighbors check their area and decide whether they wake up or remain in sleeping mode with certain criteria. Our algorithm uses only 2 bit of information in communication between sensors, thus the total communication cost is low, and the speed of detecting all event region is high. We adapt two kinds of measure for the wake-up decision. With suitable threshold values, our algorithm can be applied for many applications and for the trade-off between energy saving and the efficiency of event detection.

• 한국정보처리학회논문지
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• 제7권5S호
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• pp.1666-1675
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• 2000

본 논문에서는 전자상거래 시스템에서 요구하는 상호운용성과 실시간 요구사항들을 지원할 수 있는 실시간 웹 미들웨이(RTWM Real-Time Web Middleware) 프레임워크를 제안한다. RTWM시스템은 전자상거래 시스템의 실시간 요구사항들을 지원하기 위해CORBA 객체 서비스 구조를 확장하여 이벤트 모니터, 실시간 스케줄러, 실시간 이벤트 서비스 등의 객체 컴포넌트를 포함하는 구조를 가진다. 특히, 본 논문에서는 전자상거래 사용자의 실시간 요구사항을 지원할 수 있는 실시간 이벤트 필터링을 제공하는 것에 중점을 두었다. 사용자로부터 시간적 제약조건과 원하는 이벤트 정보를 입력받아 QoS저장소에 저장하고, 실시간 이벤트가 발생하며RTFA(Real-Time Fitering Agent)를 통해 소비자가 원하는 이벤트를 필터링하여 제공하게 된다. 이로써 사용자는 보다 높은 서비스를 제공받게 되고 이 과정을 통해 전체적인 네트워크 트래픽이 감소되는 효과를 얻을 수 있다.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.211-221
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• 2020

One fundamental element of probabilistic safety assessment (PSA) is the initiating event (IE) analysis. Since IE frequencies can change over time, time-trend analysis is required to obtain optimized IE frequencies. Accordingly, such time-trend analyses have been employed to estimate industry-average IE frequencies for use in the PSAs of U.S. nuclear power plants (NPPs); existing PSAs of Korean NPPs, however, neglect such analysis in the estimation of IE frequencies. This article therefore provides the method for and results of estimating Korean industry-average IE frequencies using time-trend analysis. It also examines the effects of the IE frequencies obtained from this study on risk insights by applying them to recently updated internal events Level 1 PSA models (at-power and shutdown) for an OPR-1000 plant. As a result, at-power core damage frequency decreased while shutdown core damage frequency increased, with the related contributions from each IE category changing accordingly. These results imply that the incorporation of time-trend analysis leads to different IE frequencies and resulting risk insights. The IE frequency distributions presented in this study can be used in future PSA updates for Korean NPPs, and should be further updated themselves by adding more recent data.

• 대한안전경영과학회지
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• 제11권2호
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• pp.137-144
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• 2009

EPCIS(EPC Information Services) system is a core component of EPCglobal Architecture Framework offering information of the freights, the time of awareness and the location of awareness on the EPCglobal Network. The role of EPCIS is to exchange information based on EPC. There are four kinds of event data which are object event data, aggregation event data, quantity event data, and transaction event data. These EPCIS events data are stored and managed in EPCIS repository. This study suggest the quantitative modeling about total number of EPCIS event data under the assumption to aware the RFID tags of items, cases(boxes), vehicles(carriers, forklifts, auto guided vehicles, rolltainers) at a time on the reading points. We also estimate the number of created EPCIS event data by the suggested quantitative modeling under scenario of process in the integrated logistics center based on RFID system And this study compare the TO-BE model with the AS-IS model about the total sizes of created EPCIS event data using the simulation, in which we suggested the TO-BE model as the development of the repository by skipping the overlapped records.

• Journal of the Korean Data and Information Science Society
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• 제23권6호
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• pp.1259-1269
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• 2012

Cloud computing has rapidly become a new infrastructure for organizations to reduce their capital cost in IT investment and to develop planetary-scale distributed applications. One of the fundamental challenges in geographically distributed clouds is to provide efficient algorithms for supporting inter-cloud data management and dissemination. In this paper, we propose a geographic group quorum system (GGQS)-based hybrid algorithm for improving the interoperability of inter-cloud in time-critical event dissemination service, such as computing policy updating, message sharing, event notification and so forth. The proposed algorithm first organizes these distributed clouds into a geographic group quorum overlay to support a constant event dissemination latency. Then it uses a hybrid protocol that combines geographic group-based broad-cast with quorum-based multicast. Our numerical results show that the GGQS-based hybrid algorithm improves the efficiency as compared with Chord-based, Plume an GQS-based algorithms.

• 대한조선학회논문집
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• 제61권3호
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• pp.152-160
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• 2024

In the event of a maritime accident, search plans have traditionally been planned using experiential methods. However, these approaches cannot guarantee safety when the scale of a maritime accident increases. Therefore, this study proposes a model utilizing discrete event simulation (DES) to predict the diving time for compartment searches of a ship located on the seabed. The discrete event simulation model was created by applying the DEVS formalism. The M/V Sewol sinking was used as an example to simulate how to effectively navigate compartments of different sizes. The simulation results showed the optimal dive time with the number of decompression chambers needed to navigate the compartment as a variable. Based on this, we propose a methodology for efficient navigation planning while ensuring diver safety.