• Korea Science and Art Forum
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• v.30
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• pp.427-440
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• 2017

The objective of this study is to explore differential effects of the sustainability perceived by domestic and international participants in the MICE (Meetings, Incentive Travel, Convention, and Exhibition) held in the Republic of Korea and to examine the relationship between customer loyalty and perception of the sustainable MICE. In this study, 30 sustainability variables for the MICE were extracted and tested by the factor analysis, representing four underlying dimensions: economic sustainability, social sustainability, environmental sustainability and event sustainability. The results revealed that significant differences in these four dimensions of the sustainable MICE were perceived by domestic and international participants. The largest difference were perceived by domestic and international participants with respect to the environmental sustainability factor. The mean scores indicated that international participants tended to give higher evaluations than domestic participants. Second, there were statistically significant relationships among economic, environmental, and event sustainability factors and customer loyalty from the perspective of international participants. For domestic participants, only event sustainability had a vital relationship with customer loyalty. The study implied how policy makers and the MICE managers should adopt four dimensions of sustainability to establish a harmonious and sustainable MICE practices.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.39 no.2
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• pp.129-137
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• 2016

To identify the cause of the error and maintain the health of system, an administrator usually analyzes event log data since it contains useful information to infer the cause of the error. However, because today's systems are huge and complex, it is almost impossible for administrators to manually analyze event log files to identify the cause of an error. In particular, as OpenStack, which is being widely used as cloud management system, operates with various service modules being linked to multiple servers, it is hard to access each node and analyze event log messages for each service module in the case of an error. For this, in this paper, we propose a novel message-based log analysis method that enables the administrator to find the cause of an error quickly. Specifically, the proposed method 1) consolidates event log data generated from system level and application service level, 2) clusters the consolidated data based on messages, and 3) analyzes interrelations among message groups in order to promptly identify the cause of a system error. This study has great significance in the following three aspects. First, the root cause of the error can be identified by collecting event logs of both system level and application service level and analyzing interrelations among the logs. Second, administrators do not need to classify messages for training since unsupervised learning of event log messages is applied. Third, using Dynamic Time Warping, an algorithm for measuring similarity of dynamic patterns over time increases accuracy of analysis on patterns generated from distributed system in which time synchronization is not exactly consistent.

• Nuclear Engineering and Technology
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• v.55 no.10
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• pp.3822-3830
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• 2023

The large-area Compton camera (LACC), featuring significantly high detection sensitivity, was developed for high-speed localization of gamma-ray sources. Due to the high gamma-ray interaction event rate induced by the high sensitivity, however, the multiplexer-based data acquisition system (DAQ) rapidly saturated, leading to deteriorated energy and imaging resolution at event rates higher than 4.7 × 10³ s^-1. In the present study, a new simultaneous multi-channel DAQ was developed to improve the energy and imaging resolution of the LACC even under high event rate conditions (10⁴-10⁶ s^-1). The performance of the DAQ was evaluated with several point sources under different event rate conditions. The results indicated that the new DAQ offers significantly better performance than the existing DAQ over the entire energy and event rate ranges. Especially, the new DAQ showed high energy resolution under very high event rate conditions, i.e., 6.9% and 8.6% (for 662 keV) at 1.3 × 10⁵ and 1.2 × 10⁶ s^-1, respectively. Furthermore, the new DAQ successfully acquired Compton images under those event rates, i.e., imaging resolutions of 13.8° and 19.3° at 8.7 × 10⁴ and 10⁶ s^-1, which correspond to 1.8 and 73 μSv/hr or about 18 and 730 times the background level, respectively.

• Journal of IKEEE
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• v.24 no.2
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• pp.426-434
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• 2020

FMI is being researched as a standard for linking large-scale simulation of CPS. In order to guarantee the reliability of the results in large-scale simulations using FMI, event handling through time management techniques is required. This paper aims to guarantee real-time performance and accuracy in large-scale co-simulation environments such as CPS. Synchronize the wallclock time and simulation time to ensure real time. Also, to ensure the accuracy, before the simulation, the event is checked and the simulation is performed with the smallest step size while maintaining the real time until the event occurrence time. As a result, the events occurring in the co-simulation environment are processed immediately and sequentially, ensuring the real-time performance and minimizing the numerical integration error by maximizing the simulation resolution. In the experiment, the proposed method was processed immediately, and it was confirmed that the numerical integration error is reduced by about 1/5 unlike the existing time management method which does not guarantee the resolution.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.400-408
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• 2009

Simulation applications for analyzing the productivity of construction operations at operation level and project schedules at project level are crucial methods in project management. The application at two different levels should be very tightly linked to each other in practice. However, appropriate integration at the levels is not achieved in that existing systems do not support to integrate operation models into a schedule model. This paper presents a new approach named to Discrete Event Simulation-Nesting modeling approach, which supports not only productivity analysis at operation level but also schedule management at a project level. The system developed by the authors allows creating operation models at the operation level, maintaining them in operation model library, executing sensitivity analysis to find the behaviors of the operation models when different combination of resources are used as existing DES systems do. On top of the conventional functions, the new system facilitates to find the optimum solution of resource combinations which satisfy the user's interest by computing the hourly productivity and the hourly cost of the operation. By drag-and-dropping an operation model kept in the operation model library, the operation models are integrated into an activity of the schedule model. When a complete schedule model is established by nesting operation models into the schedule model, stochastic simulation based scheduling is executed. A case study is presented to demonstrate the new simulation system and verify the validity of the system.

• KNOM Review
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• v.22 no.1
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• pp.11-19
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• 2019

As technology develops, the latest security threats on the network applied to users are increasing. By attacking industrial or corporate systems with malicious purposes, hackers cause many social problems such as confidential information leakage, cyber terrorism, infringement of information assets, and financial damage. Due to the complex and diversified threats, the current security personnel alone are not enough to detect and analyze all threats. In particular, the Supervisory Control And Data Acquisition (SCADA) used in industrial infrastructures that collect, analyze, and return static data 24 hours a day, 265 days a year, is very vulnerable to real-time security threats. This paper introduces security information and event management (SIEM), a powerful integrated security management system that can monitor the state of the system in real time and detect security threats. Next, we compare SIEM solutions from various companies with the open source SIEM (OSSIM) from AlienVault, which is distributed as an open source, and present cases using the OSSIM and how to utilize it.

• Proceedings of the CALSEC Conference
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• 2004.02a
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• pp.255-257
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• 2004

Customer Relationship Management CRM(Customer Relationship Management) is a customer-focused business strategy designed to optimized profitability, revenus and customer satisfaction [Gartner Group](omitted)

• Korean Management Science Review
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• v.11 no.1
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• pp.107-115
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• 1994

Stochastic manufacturing systems are generally formulated as performance models of discrete event systems. In this paper, logical models(as opposed to performance models) of kanban systems are presented which are deterministic and untimed but not stochastic and timed. As a result, the first and second order properties of kanban systems are showed which can be fruitfully applied to the analysis and design of kanban systems.

• Korean Security Journal
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• no.33
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• pp.163-195
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• 2012

Various kinds of performances and events have been held by local governments along with the worldwide popularity of K-pop, and there is a growing concern about possible accidents. Actually, a large-scale of accident took place during the MBC pop song concert in Sangju Sports Stadium in October 3, 2005. And another great safety accident occurred during an open event in the Lotte World in Seoul in March 26, 2006. The purpose of this study is to propose improvement of security company that carry out security activity through the analysis of the cases of accidents and common causes in the event sites. The improvement of safety management for large-scale event site by the study are as followings; First, institutional measures should be taken to extend the size of private security companies. Second, more education and training should be provided for security personnels who work for the event. Third, private security companies should prepare for the security measures more thoroughly in advance. Fourth, private security companies should make every possible effort to maintain order in the event site. Fifth, private security companies should bolster their collaboration with relevant organizations. Sixth, security companies should take actions to make themselves completely ready for any possible unexpected situations.

• The Korean Journal of Financial Management
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• v.26 no.1
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• pp.65-94
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• 2009

The event of change in KOSPI 200 Index composition is one of the main subjects for the test of EMH. According to EMH, when a certain event is not related with firm's fundamental value, stock price should not change after the announcement of news. This hypothesis leads us to the conclusion of horizontal demand curve of stock. This logic was questioned by Shleifer(1986) and argued that downward sloping demand curve hypothesis was supported. But Harris and Gruel(1986) found a different empirical evidence that price reversal occurs in the long run, which is called price pressure hypothesis. They argued that short term price effect by large block trading (price pressure) is offset in the long run because these event is unrelated to fundamental value. Therefor, they argued that EMH can not be rejected in the long run. Until now, there are two empirical studies with Korean market data in this area. Using a data with same time period of $1996{\sim}1999$, Kweon and Park(2000) and Ahn and Park(2005) showed that stock price or beta is not significantly affected by change in index composition. This study retested this event expanding sample period from 1996 to 2006, and analyzed why this event was considered an uninformative events in the preceding studies. We analyzed a market impact by separating samples according to firm size and market condition. In case of newly enlisted firm, we found the evidence supporting price pressure hypothesis on average. However, we found the long run price effect in the sample of large firms under bearish markets. At the same time, we know that the number of samples under the category of large firms under bearish markets is relatively small, which drives the same result of supporting the hypothesis that change in index composition is a non-informative event on average. Also, the long run price effect of large size firms under bearish markets was supported by the analyses using trading volumes. On the other hand, in case of delisting from the index, we found the long run price effect but that was not supported by trading volume analyses.