• Nuclear Engineering and Technology
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• v.37 no.3
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• pp.231-244
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• 2005

In recent decades, significant effort has led to risk-informed improvements to regulation. Performance-based approaches also promise significant gains in efficiency (level of safety versus effort). However, significant work remains to be done before performance-based approaches realize their full potential in regulation of nuclear power plants. This paper reviews key concepts related to performance-based regulation, discusses some applications of performance-based approaches, and identifies issues that still need to be addressed. Realistic, experience-based models of licensee performance are still lacking; this makes it difficult to assess the prospective effectiveness of any given regulatory approach, in light of the performance issues that it will actually face. Also, while 'compliance' is an intuitively straightforward concept to apply within a prescriptive implementation, its analog in a performance-based approach remains unclear. An overarching theme of the paper is that formal methods of decision analysis are very helpful in developing appropriate regulatory approaches, especially performance-based ones; this theme is illustrated at several points.

• Journal of the Korean Data and Information Science Society
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• v.21 no.2
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• pp.327-333
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• 2010

This study examines the impact different proxies of agency costs have on companies under different governance approaches. The two specific proxies of agency costs used include: (i) the ratio of operating expenses to annual sales; and (ii) the ratio of annual sales to total assets. Our study is based on earlier works of Ang et al. (2000) and Fleming et al. (2005). A comparison of results for small unlisted companies both in US and Australia indicate that agency cost measures have statistically: (1) different result under rule-based governance mechanisms; and (2) the same results under principle-based governance mechanisms. Our findings support the view that the effectiveness different measures of agency cost is dependent on country specific governance facto as well as on the governance approaches adopted. Our results offer insights to both practitioners and policy makers regarding the usefulness of different proxies of agency costs when companies adopt principle-based corporate governance approaches versus rule-based approaches.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.591-604
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• 2009

This paper presents some important issues in modeling rock behaviour around an underground opening at depth which characterized as stress-induced fractural failure of rock. Unlike other conventional modeling approaches, stress-induced rock failure is highly complex process due to its own heterogeneous and discrete natures. Because of this complexity, many researchers has been struggled to mimic such processes as close as possible to reality with various approaches in both analytical, and numerical approaches for past few decades. Such approaches which are based on continuum mechanics, analytical fracture mechanics, and DEM(Discrete Element Method) were explored in this paper, and fundamental shortcomings for each approaches were illustrated here. In addition, DEM approach using $PFC^{2D}$(Particle Flow Code) was also implemented and illuminated in this paper and discuss the improvement and considerations for the future research.

• Journal of Communications and Networks
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• v.18 no.1
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• pp.8-18
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• 2016

In this paper, we propose a number of blind equalization approaches for time-varying andmulti-path channels. The approaches employ cost reference particle filter (CRPF) as the symbol estimator, and additionally employ either least mean squares algorithm, recursive least squares algorithm, or $H{\infty}$ filter (HF) as a channel estimator such that they are jointly employed for the strategy of "Rao-Blackwellization," or equally called "mixture filtering." The novel feature of the proposed approaches is that the blind equalization is performed based on direct channel estimation with unknown noise statistics of the received signals and channel state system while the channel is not directly estimated in the conventional method, and the noise information if known in similar Kalman mixture filtering approach. Simulation results show that the proposed approaches estimate the transmitted symbols and time-varying channel very effectively, and outperform the previously proposed approach which requires the noise information in its application.

• Journal of Electrical Engineering and Technology
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• v.9 no.6
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• pp.2107-2113
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• 2014

Particle filtering (PF) has shown its outperforming results compared to that of classical Kalman filtering (KF), particularly for highly nonlinear problems. However, PF may not be universally superior to the extended KF (EKF) although the case (i.e. an example that the EKF outperforms PF) is seldom reported in the literature. Particularly, PF approaches show degraded performance for problems where the state noise is very small or zero. This is because particles become identical within a few iterations, which is so called particle impoverishment (PI) phenomenon; consequently, no matter how many particles are employed, we do not have particle diversity regardless of if the impoverished particle is close to the true state value or not. In this paper, we investigate this PI phenomenon, and show an example problem where a classical KF approach outperforms PF approaches in terms of mean squared error (MSE) criterion. Furthermore, we compare the processing speed of the EKF and PF approaches, and show the better speed performance of classical EKF approaches. Therefore, PF approaches may not be always better option than the classical EKF for nonlinear problems. Specifically, we show the outperforming result of unscented Kalman filter compared to that of PF approaches (which are shown in Fig. 7(c) for processing speed performance, and Fig. 6 for MSE performance in the paper).

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1864-1874
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• 2007

Korean trains pass many mountain areas, so the volume of structures like bridge and tunnel has large part of railway lines. Train speed-up naturally needs a straight line in railway, then structures are increasing, and the length of structure has more than 70% in Kyongbu high-speed railway. The stiffness of bridge and tunnel is higher than the soil in the roadbed in spite of dynamic difference in vibration and displacement. Differences in stiffness have more dynamic effects and increase the deformation and destruction in the track and roadbed. This influences passenger's comfort and the safety of operation, and it needs more track maintenance. This study selected tunnel with ballast track, tunnel with concrete track, and structure's approaches with short maintenance cycle in the roadbed and had track acceleration tests and track liner inspections using track master in the field. This study will measure periodically to structure's approaches which have very fast track irregularity and analyze dynamic differences and track irregularity near structure's approaches, so realize the cause of track irregularity of structure's approaches and use basic data for reasonably strengthening method of structure's approaches.

• Nuclear Engineering and Technology
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• v.50 no.8
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• pp.1217-1233
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• 2018

Following a surge of interest in multi-unit risk in the last few years, many recent studies have suggested methods for multi-unit probabilistic safety assessment (MUPSA) and addressed several related aspects. Most of the existing studies though focused on two-unit nuclear power plant (NPP) sites or used rather simplified probabilistic safety assessment (PSA) models to demonstrate the proposed approaches. When considering an NPP site with three or more units, some approaches are inapplicable or yield very conservative results. Since the number of such sites is increasing, there is a strong need to develop and validate practical approaches to the related MUPSA. This article provides several detailed approaches that are applicable to multi-unit Level 1 PSA for sites with up to six or more reactor units. To validate the approaches, a multi-unit Level 1 PSA model is developed and the site core damage frequency is estimated for each of four representative multi-unit initiators, as well as for the case of a simultaneous occurrence of independent single-unit initiators in multiple units. For this purpose, an NPP site with six identical OPR-1000 units is considered, with full-scale Level 1 PSA models for a specific OPR-1000 plant used as the base single-unit models.

• Journal of Gifted/Talented Education
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• v.18 no.3
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• pp.465-496
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• 2008

With leadership and speciality, creativity is cutting a fine figure among major values of human resource in 21C knowledge-based society. In the 7th school curriculum much emphasis is put on the importance of creativity by pursuing the image of human being based on creativity based on basic capabilities'. Also creativity is one of major factors of giftedness, and developing one's creativity is the core of the program for gifted education. Doing mathematics requires high order thinking and knowledgeable understandings. Thus mathematical creativity is used as a measure to test one's flexibility, and therefore it is the basic tool for creativity study. But theoretical study for mathematical creativity is not common. In this paper, we discuss mathematical creativity applied to 6 approaches suggested by Sternberg and Lubart in educational theory. That is, mystical approaches, pragmatical approaches, psycho-dynamic approaches, cognitive approaches, psychometric approaches and scio-personal approaches. This study expects to give useful tips for understanding mathematical creativity and understanding recent research results by reviewing various aspects of mathematical creativity.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.33 no.3
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• pp.99-114
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• 2020

Objectives : To investigate treatment approaches of psoriasis, and to provide universal and holistic standards to assist in optimizing patient care and future research. Methods : Review articles of psoriasis regarding pathophysiology, risk factor or treatment were searched from Pubmed (January 2016 to June 2020). Treatment approaches were investigated based on the searched articles. Additional data collecting was done for further discussion by searching Pubmed and Google scholar with keywords relevant to the approaches, and the relevant references of articles retrieved were manually inspected to be included. Results : Modalities to directly regulate the relevant helper T cell or inflammatory cytokines can constitute the treatment approaches of psoriasis. Modalities to treat gastrointestinal tract inflammation, to correct metabolic syndrome and to improve epidermal lipid abnormality via whole body lipid metabolism can also constitute the treatment approaches of psoriasis. Probable adverse effects of long term use of western medication should be addressed carefully, and alleviating the hazards of western medication can be a treatment approach of psoriasis. Conclusion : Treatment of psoriasis should take account of systemic aspects such as gastrointestinal tract and lipid metabolism. Treatment approaches of psoriasis established on the pathophysiological basis can serve as universal standards.

• International Journal of Computer Science & Network Security
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• v.22 no.12
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• pp.116-124
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• 2022

Information and communication technologies used in the social sphere are born due to the development of computer technologies. The main task of the distance learning process in higher education institutions is not to provide information, but to teach how to obtain and use it. The purpose of the article: to identify innovative approaches in the training of specialists in higher education institutions in the context of distance learning. Various innovative approaches to organizing the work of students of higher educational institutions in the context of distance learning are considered. Based on the conducted research, it is concluded that each of the approaches described by us outlines the study of the phenomenon of professional training of a specialist in the condition of distance learning. All the described approaches significantly contribute to the improvement of professional training of specialists, encourage students to self-improvement, professional development and enrich their professional competence in modern conditions. The emergence and spread of innovative technologies means not only a change in the activity itself and its inherent means and mechanisms of its implementation, but also a significant restructuring of goals, value orientations, specific knowledge, skills and abilities. Therefore, the current stage of the development of civilization, scientific and technological progress requires the emergence of such specialists who would have broad humanitarian thinking, would have good psychological training, would be able to build professional activities according to laws that take into account the relationship between economic productivity and creativity, as well as the desire of the individual for constant renewal, self-realization. Only such qualities will help you master the specifics of innovative technologies well. We see the prospects in the study of innovative approaches to training specialists in higher education institutions in the condition of distance learning in foreign countries.