• Title/Summary/Keyword: multiple events

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Design and Implementation of Real-Time Parallel Engine for Discrete Event Wargame Simulation (이산사건 워게임 시뮬레이션을 위한 실시간 병렬 엔진의 설계 및 구현)

  • Kim, Jin-Soo;Kim, Dae-Seog;Kim, Jung-Guk;Ryu, Keun-Ho
    • The KIPS Transactions:PartA
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    • v.10A no.2
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    • pp.111-122
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    • 2003
  • Military wargame simulation models must support the HLA in order to facilitate interoperability with other simulations, and using parallel simulation engines offer efficiency in reducing system overhead generated by propelling interoperability. However, legacy military simulation model engines process events using sequential event-driven method. This is due to problems generated by parallel processing such as synchronous reference to global data domains. Additionally. using legacy simulation platforms result in insufficient utilization of multiple CPUs even if a multiple CPU system is under use. Therefore, in this paper, we propose conversing the simulation engine to an object model-based parallel simulation engine to ensure military wargame model's improved system processing capability, synchronous reference to global data domains, external simulation time processing, and the sequence of parallel-processed events during a crash recovery. The converted parallel simulation engine is designed and implemented to enable parallel execution on a multiple CPU system (SMP).

Importance Assessment of Multiple Microgrids Network Based on Modified PageRank Algorithm

  • Yeonwoo LEE
    • Korean Journal of Artificial Intelligence
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    • v.11 no.2
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    • pp.1-6
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    • 2023
  • This paper presents a comprehensive scheme for assessing the importance of multiple microgrids (MGs) network that includes distributed energy resources (DERs), renewable energy systems (RESs), and energy storage system (ESS) facilities. Due to the uncertainty of severe weather, large-scale cascading failures are inevitable in energy networks. making the assessment of the structural vulnerability of the energy network an attractive research theme. This attention has led to the identification of the importance of measuring energy nodes. In multiple MG networks, the energy nodes are regarded as one MG. This paper presents a modified PageRank algorithm to assess the importance of MGs that include multiple DERs and ESS. With the importance rank order list of the multiple MG networks, the core MG (or node) of power production and consumption can be identified. Identifying such an MG is useful in preventing cascading failures by distributing the concentration on the core node, while increasing the effective link connection of the energy flow and energy trade. This scheme can be applied to identify the most profitable MG in the energy trade market so that the deployment operation of the MG connection can be decided to increase the effectiveness of energy usages. By identifying the important MG nodes in the network, it can help improve the resilience and robustness of the power grid system against large-scale cascading failures and other unexpected events. The proposed algorithm can point out which MG node is important in the MGs power grid network and thus, it could prevent the cascading failure by distributing the important MG node's role to other MG nodes.

A Study on the Difference Between Wife and Husband in the Level of Stress Recognition and Distress (부부간의 스트레스 인지수준 및 디스트레스 수준의 차이에 관한 연구)

  • 최동숙
    • Journal of the Korean Home Economics Association
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    • v.27 no.1
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    • pp.165-179
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    • 1989
  • The purpose of this study is to examine the difference between wife and husband in the level of stress recognition and distress subsequent to the life events, and thus 5 kinds of study questions have been established for the achievement of this purpose. Data were obtained from 371 couples who resided in Seoul through Likert-Type questionaire, and Frequency, Percentage, Mean, T-Test, One Way ANOVA, Pearson ${\gamma}$ Correlation, Multiple Regression, Cronbach ${\alpha}$ Coefficient were calculated. As the result of this studay, the experiences subsequent to life events, the level stress recognition and distress was different from wife and husband, and it was generally shown that those are higher for wife rather than husband.

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What is the Meaning of Black in Korean Traditional Mourning Dress?

  • Park, Saet Byul;DeLong, Marilyn
    • International Journal of Costume and Fashion
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    • v.14 no.2
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    • pp.81-96
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    • 2014
  • The meanings of colors vary with time and space. For the most important events in a person's life, such as wedding or funeral, people use color to symbolize their identities or roles. Traditionally, the colors of dress had indicated the wearer's age, class, or marital status in Korea. However, Korea's exposure to western cultures has affected in many dimensions of its modern history. Especially, influenced by social change, the traditional dress has undergone many modifications in forms, silhouettes, materials, and color. However, women's mourning dress has been maintained as a long lasting tradition and the use of white in mourning dress has been regarded as a norm until recently, while men have worn a regular black suit with a black tie. But, the shift from white to black in mourning dress has been observed in recent mourning practices. To examine this change of color in Korean traditional mourning dress, a historical approach utilizing multiple resources, such as interview, observations of events, documents, and archival records was applied.

Unstable Phenomenon of High-Speed Rotating Circular Saws (고속회전 원형 톱의 불안정 현상)

  • ;C. D. Mote, Jr.
    • Journal of KSNVE
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    • v.9 no.6
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    • pp.1210-1217
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    • 1999
  • This paper presents schematic process of identifying the principal cause to make the vibration problem of rotating circular saws. In the tandem pencil slat saw lines, feeding of cedar blocks is often stopped because excessive motro current is required in a saw motor. These events are called "kick-offs" in technical reports. Research on saw behavior at kick-offs is required to understand are reduce the frequency and severity of kick-offs events. This research aims at finding out the principal cause of kick-offs, and evloving design improvements for high cutting performance with fewer and less severe kick-offs. Measurements of critical speed, cutting force, cutting temeprature and dynamic displacements are carried out to observe the instability mechanism and also to obtain saw design parameters for the numerical analyses. And the numerical analyses involving FEM and multiple scale method are utilized to show the possibility of the principal cause.pal cause.

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An Empirical Research on the Effect of Social Scaffolding of Virtual Community on its Growth and Thrift (가상 커뮤니티의 사회적 기반요소가 커뮤니티 활성화에 미치는 영향에 관한 실증 연구)

  • 김효근;이경연;강소라
    • Journal of Information Technology Applications and Management
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    • v.10 no.1
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    • pp.35-46
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    • 2003
  • This study focuses on the effect of Social Scaffolding of virtual community on its growth and thrift. The research model proposed in this study is that communities, which have goof social scaffolding, tend to grow and thrive. Social Scaffolding refers to those aspects of a site Purpose, Places, Profiles, leaders, Roles, Rules, Cyclic Events, integrating with the real world, and Subgroups. The data were collected from 100 virtual communities in Daum Communications and analyzed in this study. Multiple regression is used to analyze the relationship of variables. The result is following ; purpose, loaders, rules, integrating with the real world support the effects of social scaffolding of virtual community on its growth and thrift, but profiles, roles, cyclic events do not. The result of this study implies the importance of social scaffolding of virtual community for re-searches, and developers.

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QoS Adaptive Inter-piconet Scheduling in Bluetooth Scatternet for Wireless PANs

  • Kim Tae-Suk;Kim Sehun
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2004.10a
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    • pp.345-348
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    • 2004
  • Every bridge node participating in multiple piconets and forming a scatternet should schedule the inter-piconet traffics in an efficient manner. Frequent piconet switching due to short polling intervals for the links of a bridge node leads to considerable time slots loss caused by the guard time and power consumption for transceiving and processing. On the other hand, restrained piconet switching may result in failures of fulfilling QoS (Quality of Service) requirements for some links. Tn this paper, we present a QoS aware inter-piconet scheduling scheme minimizing the piconet switching events within guaranteed QoS requirements. According to simulation results, the proposed scheme is confirmed to have great improvement in throughput and number of switching events over the credit scheme as current inter-piconet scheduling scheme for the scatter mode.

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Lessons Learned and Challenges Encountered in Retail Sales Forecast

  • Song, Qiang
    • Industrial Engineering and Management Systems
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    • v.14 no.2
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    • pp.196-209
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    • 2015
  • Retail sales forecast is a special area of forecasting. Its unique characteristics call for unique data models and treatment, and unique forecasting processes. In this paper, we will address lessons learned and challenges encountered in retail sales forecast from a practical and technical perspective. In particular, starting with the data models of retail sales data, we proceed to address issues existing in estimating and processing each component in the data model. We will discuss how to estimate the multi-seasonal cycles in retail sales data, and the limitations of the existing methodologies. In addition, we will talk about the distinction between business events and forecast events, the methodologies used in event detection and event effect estimation, and the difficulties in compound event detection and effect estimation. For each of the issues and challenges, we will present our solution strategy. Some of the solution strategies can be generalized and could be helpful in solving similar forecast problems in different areas.

Factors influencing the resilience of firefighters (소방공무원의 극복력에 영향을 미치는 요인)

  • Kim, Jin Woo;Song, Hyo-Suk
    • The Korean Journal of Emergency Medical Services
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    • v.25 no.1
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    • pp.37-48
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    • 2021
  • Purpose: The purpose of this study was to identify the degree of resilience, traumatic events, secondary traumatic stress, and calling reported by firefighters and to identify the factors affecting the resilience of firefighters. Methods: Data were collected using structured questionnaires and 200 fire officials working in D city were enrolled as the subjects. Data were analyzed using SPSS 24.0, and the analyses included descriptive statistics, independent t-test, ANOVA, Scheffé test, Pearson correlation coefficient, and multiple linear regression. Results: The difference in resilience according to general characteristics showed significant differences in health status (F=4.33, p=.014) and job satisfaction (F=6.13, p=.003). The factors affecting resilience were identified as calling (β=.25, p<.001), and the explanatory power for resilience was 19.2%. Conclusion: It is necessary to increase calling in order to increase resilience. Therefore, we suggest that professional education and programs that consider personal characteristics are needed to strengthen the calling.

DeepSDO: Solar event detection using deep-learning-based object detection methods

  • Baek, Ji-Hye;Kim, Sujin;Choi, Seonghwan;Park, Jongyeob;Kim, Jihun;Jo, Wonkeum;Kim, Dongil
    • The Bulletin of The Korean Astronomical Society
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    • v.46 no.2
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    • pp.46.2-46.2
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    • 2021
  • We present solar event auto detection using deep-learning-based object detection algorithms and DeepSDO event dataset. DeepSDO event dataset is a new detection dataset with bounding boxed as ground-truth for three solar event (coronal holes, sunspots and prominences) features using Solar Dynamics Observatory data. To access the reliability of DeepSDO event dataset, we compared to HEK data. We train two representative object detection models, the Single Shot MultiBox Detector (SSD) and the Faster Region-based Convolutional Neural Network (R-CNN) with DeepSDO event dataset. We compared the performance of the two models for three solar events and this study demonstrates that deep learning-based object detection can successfully detect multiple types of solar events. In addition, we provide DeepSDO event dataset for further achievements event detection in solar physics.

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