• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.836-842
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• 2016

When an accident occurs in the nuclear power plant, the faulted information might mislead to the high possibility of aggravating the accident. At the Fukushima accident, the operators misunderstood that there was no core exposure despite in the processing of core damage, because the instrument information of the reactor water level was provided to the operators optimistically other than the actual situation. Thus, this misunderstanding actually caused to much confusions on the rapid countermeasure on the accident, and then resulted in multiplying the accident propagation. It is necessary to be equipped with the function that informs operators the status of instrument integrity in real time. If plant operators verify that the instruments are working properly during accident conditions, they are able to make a decision more safely. In this study, we have performed various tests for the fault detection sensitivity of an data-driven empirical model to review the usability of the model in the accident conditions. The test was performed by using simulation data from the compact nuclear simulator that is numerically simulated to PWR type nuclear power plant. As a result of the test, the proposed model has shown good performance for detecting the specified instrument faults during normal plant conditions. Although the instrument fault detection sensitivity during plant accident conditions is lower than that during normal condition, the data-drive empirical model can be detected an instrument fault during early stage of plant accidents.

• The Journal of Industrial Distribution & Business
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• v.11 no.4
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• pp.19-30
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• 2020

Purpose: The purpose of this study examines the mediating effect of clan leadership in the relationship between hierarchy culture and organizational commitment. Most previous research focused on the relationship between organizational culture and organizational performance or organizational culture and job satisfaction. There are few empirical studies that focus on organizational commitment data because it is difficult to collect in many cases of export-driven small and medium sized enterprises. However, this research measures affective commitment, continuance commitment, and normative commitment differently than previous research, which is mostly focused on the hierarchy culture, clan leadership, and organizational commitment measurements. Research design, data, methodology: Conceptual research model is based on the studies of Cameron and Quinn (2011), and Gungor and Sahin (2018). The model is designed with three constructs such as hierarchy culture, organizational commitment, and clan leadership. The monitor culture and coordinator culture are as proxy for the hierarchy culture. The affective commitment, continuance commitment, and normative commitment are as proxy for the organizational commitment. And also the facilitator leadership and mentor leadership are as proxy for the clan leadership. Based on three hundred cases such as export-driven small and medium sized enterprises (SMEs), this study verify the hypothesis. Hypothesis was analyzed with the structural equation modeling. Results: In case of export-driven small and medium sized enterprises (SMEs), clan leadership acts as a mediator in the relationship between hierarchy culture and organizational commitment. In case of export-driven small and medium sized enterprises (SMEs) with high organizational commitment, clan leadership acts as a mediator in the relationship between hierarchy culture and organizational commitment. In case of export-driven small and medium sized enterprises (SMEs) with low organizational commitment, clan leadership did not act as a mediator in the relationship between hierarchy culture and organizational commitment. Conclusions: By controlling for the mediating effect of clan culture, this study have improved the academic contributions as well as policy and practical implications through empirical study of clan leadership that affect organizational commitment in the fields of hierarchy culture. In addition, this study means that the mediating effects on the variables of clan leadership were examined.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.90-96
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• 2018

This paper proposed data driven techniques to forecast the time point of water management of the water reservoir without measuring manganese concentration with the empirical data as Juam Dam of years of 2015 and 2016. When the manganese concentration near the surface of water goes over the criteria of 0.3mg/l, the water management should be taken. But, it is economically inefficient to measure manganese concentration frequently and regularly. The water turnover by the difference of water temperature make manganese on the floor of water reservoir rise up to surface and increase the manganese concentration near the surface. Manganese concentration and water temperature from the surface to depth of 20m by 5m have been time plotted and exploratory analyzed to show that the water turnover could be used instead of measuring manganese concentration to know the time point of water management. Two models for forecasting the time point of water turnover were proposed and compared as follow: The regression model of CR20, the consistency ratio of water temperature, between the surface and the depth of 20m on the lagged variables of CR20 and the first lag variable of max temperature. And, the Box-Jenkins model of CR20 as ARIMA (2, 1, 2).

• KEPCO Journal on Electric Power and Energy
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• v.4 no.2
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• pp.101-105
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• 2018

In this paper, the kernel regression model is applied for the case study of gas turbine abnormal state analysis. In addition to vibration analysis at the remote site, the kernel regression model technique can is useful for analyzing abnormal state of rotor vibration signals of gas turbine in power plant. In monitoring based on data-driven techniques correlated measurements, the fault free training data of shaft vibration obtained during normal operations of gas turbine are used to develop a empirical model based on auto-associative kernel regression. This data-driven model can be used to predict virtual measurements, which are compared with real-time data, generating residuals. Any faults in the system may cause statistically abnormal changes in these residuals and could be detected. As the result, the kernel regression model provides information that can distinguish anomalies such as sensor failure in a shaft vibration signal.

• International Journal of Air-Conditioning and Refrigeration
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• v.9 no.1
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• pp.11-19
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• 2001

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which was a short tube haying a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them. and it would enhance the seasonal energy efficiency ratio of an inverter heat pump system, Based on experimental data, a semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model`s prediction was within $\pm$5%.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.1
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• pp.109-116
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• 1999

To establish optimum cycle of the inverter-driven heat pump with a variation of frequency, the bypass orifice, which is a short tube having a bypass hole in the middle, was designed and tested. Flow characteristics of the bypass orifice were measured as a function of orifice geometry and operating conditions. Flow trends with respect to frequency were compared with those of short tube orifices and capillary tubes. Generally, the bypass orifice showed the best flow trends among them, that will enhance the seasonal energy efficiency ratio of an inverter heat pump system. Based on experimental data, the semi-empirical flow model was developed to predict mass flow rate through bypass orifices. The maximum difference between measured data and model's prediction was within ${\pm}5%$.

• Journal of Digital Convergence
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• v.20 no.3
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• pp.181-189
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• 2022

The purpose of this study is to investigate the innovation of business model and the effectiveness of the data-driven model. the main concepts and policies related to the data economy are reviewed, and implications are drawn through the analysis of data-based convergence service creation cases. This study identified the existing data-driven business model of the creation of MyData service industry in the financial industry and concept of the data economy. According to the empirical analysis result, this study confirmed that t considering the mobile environment and consumer acceptance of data portability, the ripple effect of the implementation of My Data on the financial industry is expected to be significant.

• Water for future
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• v.26 no.3
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• pp.47-61
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• 1993

A menu-driven shell program DSFS (Daily Streamflow Simulation Model), that can process the input data, optimize the parameters, execute the program, and graphically display the results of a modified tank model, was developed and applied to simulating daily streamflow from small watersheds. The model defines daily watershed evapotranspiration losses from potential values multiplied by monthly landuse coefficients and correction factors for soil water storage levels. The parameters were calibrated using observed hydrologic data for fifteen watersheds, and the results were correlated with watershed parameters to define empirical relationships. The proposed model was tested with streamflow data of ungaged conditions, and the simulation results overestimated the annual runoff.

• Journal of Information Technology Applications and Management
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• v.12 no.4
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• pp.105-121
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• 2005

Ubiquitous computing(UC) is an emerging paradigm. Its arrival as a mainstream is expected to trigger innovative UC-driven business models (UCBMs). Currently, there is no Parsimonious methodology to analyze and provide diagnostics for UCBMs. With this research, we propose a analytical architecture that enables the assessment of an UCBM in its structural strengths and weaknesses. With value logic as the cornerstone, the architecture is composed of value actors, value assets, value context, business value Propositions, customer value propositions, value creation logics, and value assumptions. Dimensional variables are initially Identified based on the review of business model literature. Then, their significance is empirically examined through 14 UCBM scenarios, and variables that are expected to Play an important role in the UCBM assessment are decided. Finally, by analyzing the scenarios in terms of the dimensional variables, we attempted to summarize general characteristics of emerging UCBMs.

• Journal of Korean Society for Quality Management
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• v.47 no.4
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• pp.861-873
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• 2019

Purpose: The purpose of this study is to investigate the effects of organizational culture, personality Traits, work addiction and workplace family conflict on the life satisfaction of Korean Air crew. Methods: The collected data through the survey were analyzed using structure equation model analysis The sample used for the empirical analysis is a total of 578 questionnaires. Results: Empirical analysis summarized next. Organizational culture and personality characteristics have some effects on work poisoning. However, the compulsion of work driven does not affect work-family conflict, Family-Work Conflict does not affect Life Satisfaction. Conclusion: This paper has a contribution in that it extends the range of the academic research concerning Workaholic. Also this paper provides implications on effective human resource management method suitable for airline industry.