• Nuclear Engineering and Technology
• /
• v.45 no.2
• /
• pp.151-164
• /
• 2013

A key input for the assessment of Human Error Probabilities (HEPs) with Human Reliability Analysis (HRA) methods is the evaluation of the factors influencing the human performance (often referred to as Performance Shaping Factors, PSFs). In general, the definition of these factors and the supporting guidance are such that their evaluation involves significant subjectivity. This affects the repeatability of HRA results as well as the collection of HRA data for model construction and verification. In this context, the present paper considers the TAsk COMplexity (TACOM) measure, developed by one of the authors to quantify the complexity of procedure-guided tasks (by the operating crew of nuclear power plants in emergency situations), and evaluates its use to represent (objectively and quantitatively) task complexity issues relevant to HRA methods. In particular, TACOM scores are calculated for five Human Failure Events (HFEs) for which empirical evidence on the HEPs (albeit with large uncertainty) and influencing factors are available - from the International HRA Empirical Study. The empirical evaluation has shown promising results. The TACOM score increases as the empirical HEP of the selected HFEs increases. Except for one case, TACOM scores are well distinguished if related to different difficulty categories (e.g., "easy" vs. "somewhat difficult"), while values corresponding to tasks within the same category are very close. Despite some important limitations related to the small number of HFEs investigated and the large uncertainty in their HEPs, this paper presents one of few attempts to empirically study the effect of a performance shaping factor on the human error probability. This type of study is important to enhance the empirical basis of HRA methods, to make sure that 1) the definitions of the PSFs cover the influences important for HRA (i.e., influencing the error probability), and 2) the quantitative relationships among PSFs and error probability are adequately represented.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.4
• /
• pp.113-119
• /
• 2023

Despite the lifting of the mandatory wearing of masks, which was the main tool of the COVID-19 quarantine policy, we paid attention to the fact that some people are still wearing masks, and we wanted to clarify why people do not take off their masks. Through a survey in this regard, we were able to ascertain why some people continue to wear masks in a broader context. In this article, we directly and indirectly confirm the hidden side of citizens' continued wearing of masks by analyzing how the lifting of the mask-wearing obligation was reported in media articles that have a significant impact on citizens' behavior and attitude. Through this, it was confirmed that citizens continue to wear masks to protect themselves in an uncertain situation where the COVID-19 endemic has not been declared, despite the quarantine authorities' announcement of lifting the mandatory wearing. In a situation where crises such as COVID-19 are expected to repeat frequently in the future, it was concluded that it is important to build trust in the quarantine authorities.

• Journal of the Korea Society of Computer and Information
• /
• v.16 no.6
• /
• pp.165-178
• /
• 2011

A gigantic ship is constructed by assembling various types of ship blocks, each block being made by cutting and piecing the steel-plates together. The steel-plate piling process as the initial stage of ship construction sorts and manages the steel-plates according to the ship blocks that the steel-plates are used to make. The steel-plate piling process poses some problems such as process delay due to piling errors, safety vulnerability due to the handling of extra heavy-weight objects, and the uncertainty of work plan due to lack of information management in the pile spaces. We constructed a steel-plate piling process system based on the context-aware computing to resolve such problems. We built simulation system that can simulate the piling process and then established a smart space within the system by using tags, sensors and a real-time location system in order to collect context information. Workers receive an appropriate or intelligent service from the system.

• Review of Culture and Economy
• /
• v.21 no.1
• /
• pp.3-20
• /
• 2018

This study investigates a comprehensive context between the vertical integration and concentration of Korean film market. The concentration of distribution and screening markets are result of industrial strategy to defend demand uncertainty and to pursue economies of scale. Major distributors are increasingly inclined to defend industrial risk by concentrating resources on blockbusters and bargaining power of the multiplex is getting strengthened by distribution competition to secure as many screens as possible. Vertically integrated multiplexes operate discriminatory preferential treatment to their affiliates, however, there is a difference in degree of discrimination between vertically integrated groups. Furthermore, it is difficult to exclude each other from the distribution competition in which the largest screen number has to be secured. It is difficult for multiplex only to pursue the interests of affiliates and make negative choices in screening performance. As the number of screening screens increases, the seat occupancy also increases. As a result, the polarization of the distribution and screening markets, including the screen monopoly, is a phenomenon that occurs commercial films centered markets and the unfair behavior of the vertically affiliated multiplex has a limited effect on the movie market.

• International Journal of Computer Science & Network Security
• /
• v.21 no.12
• /
• pp.309-315
• /
• 2021

The purpose of the article is to analyze the functioning of economic systems in the context of the development of their potential in a circular economy. It is determined that the functioning of economic systems to ensure their sustainability should meet modern challenges and provide for the formation of competitive institutional architecture, the introduction of structural and regulatory innovations, the transition to an innovative model of development. The specific principles of functioning of economic systems include openness, nonlinearity, multivectority, dynamism, emergence, uncertainty about the development of economic processes. It is substantiated that the linear nature of development and equilibrium are not dominant in the functioning of economic systems, and increasing the level of economic efficiency should go hand in hand with minimizing the activities of enterprises, which necessitates the use of circular economy. The main prerequisites for the transition to a circular economy are analyzed. It is determined that the basic concept of the circular economy involves the development of a system of production and consumption, which is based on processing, reuse, repair, product sharing, change of consumption patterns and new business models and systems. The main elements of the circular economy include: a closed cycle, the use of renewable energy sources, systems thinking. The correlation of the principles of sustainable development and the peculiarities of the application of the circular economy is analyzed. It is determined that the circular economy contrasts with the traditional linear economic model, which is based on the model of "take-do-consume-throw away". The advantages and disadvantages due to the use of the principles of circular economy are given. Based on the study, steps are identified to accelerate the transition from a linear economy to a circular economy.

• Journal of Korea Water Resources Association
• /
• v.52 no.12
• /
• pp.985-999
• /
• 2019

Over the last decade, droughts have become more severe and frequent in many regions, and several studies have been conducted to explore the recent drought. Copula-based bivariate drought frequency analysis has been widely used to evaluate drought risk in the context of point frequency analysis. However, the relatively significant uncertainties in the parameters are problematic when available data are limited. For this reason, the primary purpose of this study is to develop a regional drought frequency model based on the Copula function. All parameters, including marginal and copula functions in the regional frequency model, were estimated simultaneously. Here, we present a case study of recent drought 2013-2015 over the Han-River watershed where severe drought risk is consistently found to increase. The proposed model provided a reliable way to significantly reduce the uncertainty of parameters with a Bayesian modeling framework. The uncertainty of the joint return period in the regional frequency analysis is nearly three times lower than that of the point frequency analysis. Accordingly, DIC values in the regional frequency analysis model are significantly decreased by 15. The results confirm that the proposed model is not only reliably representing characteristics of historical droughts and dependencies between drought variables, but also providing the efficacy of understanding regional drought characteristics.

• Journal of Korea Water Resources Association
• /
• v.50 no.11
• /
• pp.745-758
• /
• 2017

The copula-based models have been successfully applied to hydrological modeling including drought frequency analysis and time series modeling. However, uncertainty estimation associated with the parameters of these model is not often properly addressed. In these context, the main purposes of this study are to develop the Bayesian inference scheme for bivariate copula functions. The main applications considered are two-fold: First, this study developed and tested an approach to copula model parameter estimation within a Bayesian framework for drought frequency analysis. The proposed modeling scheme was shown to correctly estimate model parameters and detect the underlying dependence structure of the assumed copula functions in the synthetic dataset. The model was then used to estimate the joint return period of the recent 2013~2015 drought events in the Han River watershed. The joint return period of the drought duration and drought severity was above 100 years for many of stations. The results obtained in the validation process showed that the proposed model could effectively reproduce the underlying distribution of observed extreme rainfalls as well as explicitly account for parameter uncertainty in the bivariate drought frequency analysis.

• The Journal of Engineering Geology
• /
• v.24 no.2
• /
• pp.191-199
• /
• 2014

We describe a method for detecting slope instability in flume tests using pore pressure and water content data in conjunction with a statistical control chart analysis. Specifically, we conducted univariate statistical analysis on x-MR control chart data (pore pressure and water content) collected at several points along the flume slope, which we separated into three parts: upper, middle, and lower. To assess our results in the context of landslide forecasting and warning systems, we applied control limit lines at $1{\sigma}$, $2{\sigma}$, and $3{\sigma}$ levels of uncertainty. In doing so, we observed that dispersion time varies depending on the control limit line used. Moreover, the detection of instabilities is highly dependent on the position and type of sensor. Our findings indicate that different characteristics of the data on various factors predict slope failure differently and these characteristics can be identified by univariate statistical analysis. Therefore, we suggest that a univariate statistical approach is an effective method for the early detection of slope instability.

• Journal of Korean Academy of Nursing
• /
• v.38 no.1
• /
• pp.140-151
• /
• 2008

Purpose: The purpose of this study was to understand the meanings and nature of living in the world among cancer patients. The present study adopted a hermeneutic phenomenological method which was developed by van Manen. Method: The participants for this study were 5 men and 6 women, who were over the age of 20 with admission or a follow up visit in the medical or surgical department. Data were collected by using in-depth interviews and observations from February to September, 2007. The contents of the interviews were tape-recorded with the consent of the subject. Result: The essential themes that fit into the context of the 4 existential grounds of body, time, space and other people were: a body that cannot be restored, a body that endures and lives, waiting in uncertainty, a valued calculation for the living day, being in a world of invisible power, reestablishing relationships, and reflection on his or her life. Conclusion: These findings revealed that living in the world is affected to varying degrees by the cancer. It is important for nurses to identify and take care of disabilities and to support the reorientation in the disintegrated life situation. The result of this study can give nurses some insight into these experiences and help promote empathetic care.

• Journal of Navigation and Port Research
• /
• v.34 no.7
• /
• pp.587-594
• /
• 2010

The positive and negative opinion to cargo demand of Incheon's SAMT in the near future remains cloudy. Considering port and shipping environmental changes and the logistics situation of China which explains the lack of facilities in Chinese airports, the creating of SAMT cargoes of the Incheon region could catches a favorable opportunity to be a logistics hub in the North-East Asia. On the other hand, as open-sky policy and direct-call service has been carried out between China and N.A.(North America), Incheon could cause a loss of competitiveness in SAMT because the enhancement in the aspect of the connectivity of Chinese airlines and shipping lines makes customer sent to last destination their cargoes whenever they want. In the same context, this paper analyses on conditions of domestic and international SAMT and proposes in this uncertainty future forecasting of SAMT of Incheon by scenario planning according to changes in integrated SAMT, measuring the likelihood of final scenario. This study shows the Sea & Air multi-transport volume will have either slight increase or decrease from the current condition. Consequently, RFS expansion and system & service improvement through strong ties with major cities in China will be required in a short run aspect. Nonetheless, we also need to take domestic & international transportation environment into account in the long run.