• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.261-268
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• 2000

In this study the bearing capacity of the eccentrically loaded shallow footing is estimated by means of the upper bound method of limit analysis. In the case of applying the upper bound, the results depend on the failure mechanism. So the failure surface is correctly studied through the model test using sand. New method is proposed to estimate the bearing capacity of the eccentrically loaded shallow footing by means of the upper bound method to apply the failure mechanism based on the model test. The propriety of new method is verified by the results of various methods. And the influences of the variables eccentricity, embedment depth, variations of contact width factor by model test using sand are also studied in this paper

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.27-34
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• 2003

Capacity Spectrum Method (CSM) defined in ATC-40 or FEMA-273 is a most widely used static inelastic analysis method to evaluate the performance level of the existing structures. In CSM, however, uncertainties and errors exist when lateral forces such as earthquake and wind loads are analyzed into equivalent static loads. This paper examines the accuracy of CSM for different structural parameters, such as natural frequency, yield strength and hardening ratio, and various soil conditions by comparing the estimated values to exact solutions obtained by time history analysis. Results indicate that the accuracy of CSM, in general, is influenced mostly by hardening ratio.

• Wind and Structures
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• v.31 no.4
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• pp.311-319
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• 2020

India is a developing nation and heavily spends on the development of wind power plants to meet the national energy demand. The objective of this paper is to investigate wind power potential of Ennore site using wind data collected over a period of two years by three parameter Weibull distribution. The Weibull parameters are estimated using maximum likelihood, least square method and moment method and the accuracy is determined using R² and root mean square error values. The site specific capacity factor is calculated by the mathematical model developed by three parameter Weibull distribution at different hub heights above the ground level. At last, the wind energy economic analysis is carried out using capacity factor at 30 m, 40 m and 50 m height for different wind turbine models. The analysis showed that the site has potential to install utility wind turbines to generate energy at the lowest cost per kilowatt-hour at height of 50 m. This research provides information of wind characteristics of potential sites and helps in selecting suitable wind turbine.

• Earthquakes and Structures
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• v.8 no.3
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• pp.511-539
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• 2015

The main objective of this study is to analytically investigate the effectiveness of different strengthening solutions in upgrading the seismic performance of existing reinforced concrete (RC) buildings in Nepal. For this, four building models with different structural configurations and detailing were considered. Three possible rehabilitation solutions were studied, namely: (a) RC shear wall, (b) steel bracing, and (c) RC jacketing for all of the studied buildings. A numerical analysis was conducted with adaptive pushover and dynamic time history analysis. Seismic performance enhancement of the studied buildings was evaluated in terms of demand capacity ratio of the RC elements, capacity curve, inter-storey drift, energy dissipation capacity and moment curvature demand of the structures. Finally, the seismic safety assessment was performed based on standard drift limits, showing that retrofitting solutions significantly improved the seismic performance of existing buildings in Nepal.

• Journal of the Korean Solar Energy Society
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• v.33 no.4
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• pp.46-50
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• 2013

This paper investigated wind turbine degradation quantitatively by analyzing the short-term operation records of the Shinan Wind Power Plant. Instead of a capacity factor which is needed to be normalized its variability due to monthly wind speed change, this study suggests an analysis method by taking the difference between the theoretical power output calculated from the nacelle wind speed and actual power output as the quantitative index of performance degradation. For three-year SCADA data analysis of the Shinan Wind Power Plant, it was confirmed that power output degradation rate of 0.54% per year. This value is within the average reduction rate 0.4%/year~0.9%/year of normalized capacity factor of the onshore wind power plants in U.K. and Denmark; however, lower than the rate 2%/year of Canadian wind power plants.

• Journal of the Korean Geotechnical Society
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• v.35 no.3
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• pp.17-24
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• 2019

The purpose of this study is to understand the characteristics of bearing capacity of shallow foundation on the grounds. We made a comparative study of existing bearing capacity theory, based on the three-dimensional finite element analysis with a variety of conditions such as ground condition, foundation scale and foundation shape. In the finite element analysis, the ultimate bearing capacity showed a gradual convergence in the form of exponential function or logarithm function according to the foundation scale. Although the shear strength increased, the bearing capacity tended not to increase but change linearly. In the results of comparative study of existing bearing capacity theory, bearing capacity ratio ($q_{u(FEA)}/q_{u(theory)}$) of pure sand has the outcome closest to those of the Terzaghi method. Pure clay turned out to be about 0.4~0.6 while normal soil was changed in a range of 0.3~1.3. As shear strength is increased, the results turned out to be less than 1.0. Bearing capacity ratio ($q_u/q_{u(1.0)}$), normalized at 1.0m bearing capacity, was about 35%, 15% and 5% of theoretical formula under the condition of ${\phi}=25^{\circ}$, $30^{\circ}$ and $35^{\circ}$ of pure sand; no scale effect was found with pure clay and the normal soil with lower soil strength level showed less than 10% of the theoretical formula of pure sand. Bearing capacity ratio of each case, in accordance with, the shear strength increase, was largely influenced by the internal friction angle. Shape factor of bearing capacity ratios classified by foundation shapes have different results according to the shapes; the shape factor of circular foundation is 1.50, square foundation is 1.30, rectangular and continuous foundations are 1.1~1.0.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.12
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• pp.2254-2259
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• 2011

The introduction of Personal Rapid Transit (PRT) has been widely discussed in the Korean transportation research field. However, there is no robust criterion to derive the throughput of cars and passengers at PRT stations, which plays a primary role in determining the overall capacity of PRT systems. The present study provided a methodology to rigorously compute the capacity for simple-serial PRT stations with a single platform, considering three decisive factors, i.e., the demand level of incoming cars and outgoing passengers, the station structure, and the operation strategy. A micro-level simulator was developed for the analysis of station capacity. And, by using this, station capacities were presented for various combinations of the decisive factors. In particular, the relationship between capacity and station structure was investigated in detail. Station structure is represented by the numbers of platform berths, input queue berths, and output queue berths. Moreover, both waive rate and waiting time, which represent the level of passenger service, were taken into account when the station throughput was computed.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.9 no.2
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• pp.68-74
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• 2010

In this paper, we analyze and simulate the channel capacity of a spread spectrum watermarking (SSW) technique in wireless fading channel to apply ITS system. Channel capacity analysis causing minimum effect to existing system is required necessary to apply SSW technique. We derive the channel capacity as a closed-form approximation formula in Rayleigh and Rician fading channel model. The numerical results are demonstrated and good approximated results are reported.

• Journal of Information Technology Services
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• v.17 no.1
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• pp.1-16
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• 2018

In this research, we tried to suggest the guidelines to stakeholder of ICT startup for picking up the excellent startups and nurturing them. We designed the research model focused on the good startup team's knowledge based interaction mechanism. A research model and hypotheses were developed from literature review and empirically validated. The research model consisted relationship among the knowledge sharing (knowledge donation and knowledge collection), absorptive capacity (member's ability and member's motivation), team creativity, and innovation capability. Data were collected from ICT Service Startups, and a partial least squares (PLS) analysis was made on 175 data points. The analysis results showed that absorptive capacity has significant effect on team creativity and innovation capability directly. And also it has indirect effect on the dependent variable through team creativity. On the contrary, knowledge sharing does not have statistically significant effect on team creativity and innovation capability; only have an effect on absorptive capacity. Based on the results, we proposed several team management skills for ICT startup leaders and members, and the guidelines to stakeholder such as government and private investors. Also there are some ideas for startup nurturing polices for government officers. Theoretical contributions are discussed at the end with limitations and further studies.

• International Journal of High-Rise Buildings
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• v.3 no.3
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• pp.231-241
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• 2014

Ductile fracture is one of the most common failure modes of steel beam-to-column connections in moment resisting frames. Most proposed evaluation methods of the plastic deformation capacity of a beam until ductile fracture are based on steel beam tests, where the material's yield strength/ratio, the beam's moment gradient, and loading history are the most important parameters. It is impossible and unpractical to cover all these parameters in real tests. Therefore, a new attempt to evaluate a beam's plastic deformation capacity through analysis is introduced in this paper. Another important issue is about the loading histories. Recent years, the effect on the structural component under long-duration ground motion has drawn great attentions. Steel beams tends to experience a large number of loading cycles with small amplitudes during long-duration earthquakes. However, current research often focuses on the beam's behavior under standard incremental loading protocols recommended by respective countries. In this paper, the plastic deformation capacity of steel beams subjected to long duration ground motions was evaluated through analytical methodology.