• Nuclear Engineering and Technology
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• v.52 no.9
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• pp.1983-1989
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• 2020

The human reliability analysis is a method by which, in general terms, the human impact to the safety and risk of a nuclear power plant operation can be modelled, quantified and analysed. It is an indispensable element of the PSA process within the nuclear industry nowadays. The paper herein presents a sensitivity study of the human reliability analysis performed on a real nuclear power plant-specific probabilistic safety assessment model. The analysis is performed on a pre-selected set of post-initiator operator actions. The purpose of the study is to investigate the impact of these operator actions on the plant risk by altering their corresponding human error probabilities in a wide spectrum. The results direct the fact that the future effort should be focused on maintaining the current human reliability level, i.e. not letting it worsen, rather than improving it.

• International Journal of Computer Science & Network Security
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• v.22 no.5
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• pp.25-30
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• 2022

The main purpose of the study is to analyze the main aspects of the impact of military actions on the EU labor market. The research methodology includes modern theoretical methods and methods for analyzing the state of the EU labor market. The war in Ukraine changed not only the economy of one country, but the whole continent. The European Union has very sensitively felt the changes brought about by the military actions on the territory of Ukraine. Military actions on the territory of Ukraine are a destructive factor in the labor market. Today, the main task of economic recovery is to minimize the consequences of humanitarian problems and preserve human potential, which is an important source of business activity. Based on the results of the study, we have identified key aspects of the impact of military actions on the EU labor market.

• Bulletin of the Korean Mathematical Society
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• v.60 no.2
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• pp.349-359
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• 2023

In this paper, we study ∆-transitivity, ∆-weak mixing and ∆-mixing for semigroup actions and give several characterizations of them, which generalize related results in the literature.

• ETRI Journal
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• v.39 no.4
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• pp.502-513
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• 2017

For video understanding, namely analyzing who did what in a video, actions along with objects are primary elements. Most studies on actions have handled recognition problems for a well-trimmed video and focused on enhancing their classification performance. However, action detection, including localization as well as recognition, is required because, in general, actions intersect in time and space. In addition, most studies have not considered extensibility for a newly added action that has been previously trained. Therefore, proposed in this paper is an extensible hierarchical method for detecting generic actions, which combine object movements and spatial relations between two objects, and inherited actions, which are determined by the related objects through an ontology and rule based methodology. The hierarchical design of the method enables it to detect any interactive actions based on the spatial relations between two objects. The method using object information achieves an F-measure of 90.27%. Moreover, this paper describes the extensibility of the method for a new action contained in a video from a video domain that is different from the dataset used.

• Journal of Ocean Engineering and Technology
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• v.20 no.4 s.71
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• pp.43-49
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• 2006

Detailed investigations were carried out on the stability of the dredged soil bed against wave actions, aimedat establishing the design method of artificial tidal flats using dredged soil. The soil was dredged at Nagoya port, Japan, and has a mean grain size of 0.013mm. Basic features of artificial dredged soil bed against wave actions were explained from a series of model experiments in a wave flume. The two types of section shapes were employed; one is a horizontal bed and the other is a sloped one. Changes of the bed profile, shear strength, grain size distribution and water content, according to the wave actions, were measured in detail. The cumulative effect of the wave actions, over about one week, was investigated. A dredged soil bed moves withthe wave actions with relatively small wave height. It should be especially. noted that the clay component is dissolved and flown out, away from the surface layer, and consequently the surface layer hardens, as if it is covered with sand. Wren the wave height is gradually increased, the bed is not liquefied and the shear strength of the dredged bed is increased by a wave-induced dissipation of pore pressures in the bed and a decrease of clay component by the wave-induced leakage.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.426-432
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• 2022

HVAC systems play a critical role in reducing energy consumption in buildings. Integrating occupants' thermal comfort evaluation into HVAC control strategies is believed to reduce building energy consumption while minimizing their thermal discomfort. Advanced technologies, such as visual sensors and deep learning, enable the recognition of occupants' discomfort-related actions, thus making it possible to estimate their thermal discomfort. Unfortunately, it remains unclear how accurate a deep learning-based classifier is to recognize occupants' discomfort-related actions in a working environment. Therefore, this research evaluates the classification performance of occupants' discomfort-related actions while sitting at a computer desk. To achieve this objective, this study collected RGB video data on nine college students' cold discomfort-related actions and then trained a deep learning-based classifier using the collected data. The classification results are threefold. First, the trained classifier has an average accuracy of 93.9% for classifying six cold discomfort-related actions. Second, each discomfort-related action is recognized with more than 85% accuracy. Third, classification errors are mostly observed among similar discomfort-related actions. These results indicate that using human action data will enable facility managers to estimate occupants' thermal discomfort and, in turn, adjust the operational settings of HVAC systems to improve the energy efficiency of buildings in conjunction with their thermal comfort levels.

• Journal of KIISE:Databases
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• v.28 no.3
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• pp.494-511
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• 2001

In the environment that database management systems manage disk spaces for storing databases directly, this paper proposes a correct and efficient scheme of performing pending actions for the removal of database files. As for performing pending actions, upon performing recovery, the recovery process must identify unperformed pending actions of not-yet-terminated transactions and then perform those actions completely. Making the recovery process identify those actions through the analysis of log records in the log file is the basic idea of this paper. This scheme, as an extension of the execution of transactions, fuzzy checkpoint, and recovery of ARIES, uses the following methods: First, to identify not-yet-terminated transactions during recovery, transactions perform pending actions after writing 'pa_start'log records that signify both the commit of transactions and the start of executing pending actions, and then write 'eng'log records. Second, to restore pending-actions-lists of not-yet-terminated transactions during recovery, each transaction records its pending-actions-list in 'pa_start'log record and the checkpoint process records pending-actions-lists of transactions that are decided to be committed in 'end_chkpt'log record. Third, to identify the next pending action to perform during recovery, whenever a page is updated during the execution of pending actions, transactions record the information that identifies the next pending action to perform in the log record that has the redo information against the page.

• Bulletin of the Korean Mathematical Society
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• v.57 no.2
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• pp.449-457
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• 2020

The aim of this short paper is to show some rigidity results for the actions of certain finitely presented groups by homeomorphisms. As an interesting and special case, we show that the actions of Higman-Thompson groups by homeomorphisms on a cohomology manifold with a non-zero Euler characteristic should be trivial. This is related to the wellknown Zimmer program and shows that the actions by homeomorphism could be very much different from those by diffeomorphisms.

• Journal of the Korean Mathematical Society
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• v.42 no.4
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• pp.795-826
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• 2005

We study free actions of finite abelian groups on 3­dimensional nilmanifolds. By the works of Bieberbach and Waldhausen, this classification problem is reduced to classifying all normal nilpotent subgroups of almost Bieberbach groups of finite index, up to affine conjugacy. All such actions are completely classified.

• Kyungpook Mathematical Journal
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• v.56 no.2
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• pp.577-582
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• 2016

In this paper we consider all orientation-preserving ${\mathbb{Z}}_4$-actions on 3-dimensional handlebodies $V_g$ of genus g > 0. We study the graph of groups (${\Gamma}(v)$, G(v)), which determines a handlebody orbifold $V({\Gamma}(v),G(v)){\simeq}V_g/{\mathbb{Z}}_4$. This algebraic characterization is used to enumerate the total number of ${\mathbb{Z}}_4$ group actions on such handlebodies, up to equivalence.