• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.1
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• pp.1-9
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• 2021

In this paper, we propose an IoT-based traffic safety pedestrian system for the elderly by factor analysis. The proposed system performs a factor analysis of the elderly safety variables and uses the analysis results to provide an optimal path for the elderly. In order to verify the performance of this system, we experimented with performance measurements on elderly pedestrian paths. As a result, we confirm that it provides a better safety path than mobile navigation.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.110.1-110.1
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• 2011

This study analyzed the performance of long term operation photovoltaic system The 50 kWp grid connected photovoltaic system which was installed at KEPRI site in 1999 has been operated more than 12 years. In order to acquire long term operation characteristics of medium size photovoltaic system, the operation test data related on power generation electricity and capacity factor of 50 kWp system, which have been collected since 1999, were analysed. From the analysing results, 57.7 MWh in annual power generation electricity of 50 kWp photovoltaic system in 1999 has been decreased 49.1 MWh in 2005 and reached 38.0 MWh in 2010. In addition to, the capacity factor of 50 kWp photovoltaic system also showed 13.2 % in 1999, 11.2% in 2005 and finally reached 8.8% in 2011. The operation test data showed a trend of decreasing of generation electricity and capacity factor during the 12 years operation time and we guessed that was caused by solar cell performance degradation and decreasing of PCS system efficiency.

• Journal of the Earthquake Engineering Society of Korea
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• v.20 no.3
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• pp.145-153
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• 2016

Small-size buildings are not designed by professional structural engineers in Korea. Therefore, their seismic performance can not be exactly estimated because their member sizes and reinforcement may be over- or under-designed. A prescriptive design criteria for the small-size buildings exists, but it also provides over-designed structural members since structural analysis is not incorporated, so it is necessary to revise the prescriptive criteria. The goal of this study was to provide an information for the revision, which is seismic performance and capability of small-size reinforced concrete moment frame buildings. For the study, the state of existing small-size reinforce-concrete buildings such as member size and reinforcement was identified by investigating their structural drawings. Then, over-strength, ductility and response modification factor of the small-size reinforced concrete moment frame buildings were estimated by analytical approach along with seismic performance check. The result showed that they possess moderate over-strength and ductility, and may use slightly increased response modification factor.

• Proceedings of the Safety Management and Science Conference
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• 2008.11a
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• pp.303-316
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• 2008

For the past 25 years, Korean semiconductor has experienced enormous growth to be the highest production country in the world. Semiconductor industry is very time sensitive and driven by technology and process, and requires 24-hour full operation. The environment includes many different types of equipment, utilities, different gases and toxic chemicals as well as high voltage electricity. We have performed a survey with 3-shift engineers and workers in one line. The content of the questionnaire was about the correlation between fatigue and performance shaping factor (work type and work ability), and as a result we were able to deduce the correlation, p-value and the pattern of scatter plot. The shape of the model was made of 4 blocks for fatigue, 5 blocks for work type and 5 blocks for work ability, i. e. 14 blocks in total. As a conclusion to this findings, there was a correlation between fatigue and work type and work ability specifically in semiconductor industry, and we need some effort to reduce this.

• The Journal of the Acoustical Society of Korea
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• v.38 no.3
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• pp.283-289
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• 2019

RLS (Recursive-least-squares) algorithm is known to have good convergence and excellent error level after convergence. However, there is a disadvantage that numerical instability is included in the algorithm due to inverse matrix calculation. In this paper, we propose an algorithm with no matrix inversion to avoid the instability aforementioned. The proposed algorithm still keeps the same convergence performance. In the proposed algorithm, we adopt an averaged gradient-based step size as a self-adjusted step size. In addition, a variable forgetting factor is introduced to provide superior performance for time-varying channel estimation. Through simulations, we compare performance with conventional RLS and show its equivalency. It also shows the merit of the variable forgetting factor in time-varying channels.

• Journal of Korean Academy of Nursing
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• v.45 no.3
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• pp.429-438
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• 2015

Purpose: This study was conducted to develop key performance indicators (KPIs) for home care nursing (HCN) based on a balanced scorecard, and to construct a performance prediction model of strategic objectives using the Bayesian Belief Network (BBN). Methods: This methodological study included four steps: establishment of KPIs, performance prediction modeling, development of a performance prediction model using BBN, and simulation of a suggested nursing management strategy. An HCN expert group and a staff group participated. The content validity index was analyzed using STATA 13.0, and BBN was analyzed using HUGIN 8.0. Results: We generated a list of KPIs composed of 4 perspectives, 10 strategic objectives, and 31 KPIs. In the validity test of the performance prediction model, the factor with the greatest variance for increasing profit was maximum cost reduction of HCN services. The factor with the smallest variance for increasing profit was a minimum image improvement for HCN. During sensitivity analysis, the probability of the expert group did not affect the sensitivity. Furthermore, simulation of a 10% image improvement predicted the most effective way to increase profit. Conclusion: KPIs of HCN can estimate financial and non-financial performance. The performance prediction model for HCN will be useful to improve performance.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.5
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• pp.325-333
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• 2022

This study examined the influence of three elements of individual entrepreneurial orientation (IEO), namely innovativeness, risk-taking, and proactiveness on the performance of small and medium enterprises (SMEs). It is worth noting that SMEs have experienced low productivity, low profit, and low performance during the COVID-19 pandemic era. Although several studies have shown that entrepreneurial orientation (EO) is a key factor of company performance, few have focused on IEO. This study employed a quantitative research design because all variables were measurable. It used a questionnaire to survey 384 SMEs in the service sector and employed structural equation modeling (SEM) in data analysis. The findings suggested that SMEs' performance was influenced by risk-taking and proactiveness. This could be related to the fact that SMEs have a less formal structure, allowing owner-managers to take risks and make quick decisions. Furthermore, high performance was ensured by being very sensitive to market trends and changes in the business environment. Innovativeness was not a significant factor in influencing the performance of SMEs. Perhaps it was rather difficult for SME owner-managers to be innovative due to the lack of various resources. This study successfully re-confirmed the effect of IEO on business performance and highlighted the importance of risk-taking and proactiveness in improving the performance of SMEs.

• Journal of Korean Institute of Industrial Engineers
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• v.27 no.1
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• pp.95-102
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• 2001

The design of automobile body assembly line is one of essential parts for improving the process performance. The major objective of this research is to develop a performance evaluation model for automobile assembly line using a closed queueing network(CQN) and simulation method. In this study we used a two-step approach to compute the performance of the assembly line : first, we used CQN model considering assembly line equipments and the line operating time under the assumption of no failure, and second we used a well-known simulator FACTOR/AIM. Finally we implemented this model on a K automobile company and we have shown the sample results of automobile body assembly line.

• Computers and Concrete
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• v.17 no.2
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• pp.281-294
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• 2016

The increased awareness of electromagnetic wave hazards has prompted studies on electromagnetic shielding using conductive materials in the construction industry. Previous studies have explored the effects of the types of conductive materials and their mix proportions on the electromagnetic shielding performance; however, there has been insufficient research on the effect of the geometry of the conductive materials on the electromagnetic shielding performance. Therefore, in this study, the dependence of the electromagnetic shielding performance on the cross-sectional geometry, diameter and length of fibers was investigated. The results showed that the electromagnetic shielding performance improved when the fiber length increased or the diameter decreased, but the effect of the cross-sectional geometry of the fibers was smaller than the effect of the fiber spacing factor.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.189-196
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• 2002

The capacity of CFS piers has not been used to a practical design, because there is no guide of a seismic design for CFS piers. Therefore, the guide of a seismic design value is derived from tests of CFS piers in order to apply it to a practical seismic design. Steel piers and concrete-filled steel piers are tested with constant axial load using quasi-static cyclic lateral load to check ductile capacity and using the real Kobe ground motion of pseudo-dynamic test to verify seismic performance. The results prove that CFS piers have more satisfactory ductility and strength than steel piers and relatively large hysteretic damping in dynamic behaviors. The seismic performance of steel and CFS piers is quantified on the basis of the test results. These results are evaluated through comparison of both the response modification factor method by elastic response spectrum and the performance-based design method by capacity spectrum and demand spectrum using effective viscous damping. The response modification factor of CFS piers is presented to apply in seismic design on a basis of this evaluation for a seismic performance.