• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 1996.10a
• /
• pp.253-256
• /
• 1996

Rainfall is one of the major and complicated elements of hydrologic system. Accurate prediction of rainfall is very important to mitigate storm damage. The neural network is a good model to be applied for the classification problem, large combinatorial optimization and nonlinear mapping. In this dissertation, rainfall predictions by the neural network theory were presented. A multi-layer neural network was constructed. The network learned continuous-valued input and output data. The network was used to predict rainfall. The online, multivariate, short term rainfall prediction is possible by means of the developed model. A multidimensional rainfall generation model is applied to Seoul metropolitan area in order to generate the 10-minute rainfall. Application of neural network to the generated rainfall shows good prediction. Also application of neural network to 1-hour real data in Seoul metropolitan area shows slightly good predictions.

• Smart Structures and Systems
• /
• v.16 no.3
• /
• pp.459-478
• /
• 2015

The design of a passive control solution based on tuned mass dampers (TMD's) requires the estimation of the actual masses involved in the undesired vibration. This task may result not so straightforward as expected when the vibration resides in subsets of different structural components. This occurs, for instance, when the goal is to damp out vibrations on stays. The theoretical aspects are first discussed and a design process is formulated. For sake of exemplification, a multiple TMD's configurations is eventually conceived for an existing timber footbridge located in the municipality of Trasaghis (North-Eastern Italy). The bridge span is 83 m and the deck width is 3.82 m.

• Nuclear Engineering and Technology
• /
• v.28 no.6
• /
• pp.551-562
• /
• 1996

This paper introduces the five-step methodology for identifying information needs and assessing instrument availability during the course of severe accidents in nuclear power plants. The methodology is applied to the Yonggwang (YGN) 3&4 to shed light on accident management. It constructs three safety objective trees to prevent the reactor vessel failure, to prevent the containment failure, and to mitigate the fission product release from the containment. The study assesses information needs and instrument availability under severe conditions for preventing the reactor vessel failure of YGN 3&4, and recommends additional instrument that m8y prove to be of vital importance in managing the accident.

• Korean Journal of Optics and Photonics
• /
• v.13 no.6
• /
• pp.486-492
• /
• 2002

In this paper. we presented 1 & 2 dimensional minimum mean-squared-error (MMSE) equalization scheme in a digital holographic data storage system to improve bit-error-rate (BER) and to mitigate inter-symbol interference (ISI) which were generated during the data storage and retrieval processes. We showed experimentally for ten data pages retrieved from the holographic storage system that BER and signal-to-noise ratio (SNR) were improved by adopting MMSE equalization.

• Journal of the Korea Safety Management & Science
• /
• v.5 no.2
• /
• pp.41-51
• /
• 2003

Next Generation internet banking service for important role of banking business competitive power separates service function of individual banking and should equip various service that coincides in each special qualities these are customer management, portfolio management, global corporation support etc. The past few years have been characterized by rapid changes in technology and the introduction of corporate and retail banking services through the Internet. the integration of e-banking platforms with legacy systems and the increasing dependence of banks on third party information service providers, all dramatically amplify the magnitude of risks to which banks are exposed. Risk management disciplines have not evolved at the same speed and many institutions, especially the smaller ones, have not been able to incorporate Internet banking risk controls within their existing risk management structures. This article provides an overview of the various risks which are heightened with Internet banking, and a holistic approach to managing these risks. In addition, the presentation will explain the different risk areas and the controls to be adopted to mitigate these risks.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1834-1839
• /
• 2008

The construction of concrete slab track system is increased because the system has advantages which are maintenance free and so on, the other side, the system has weak points such as increase of the cost of the early stage construction. Recently, railway environment is issued including noise. Therefore, measures which are to mitigate noise on slab tracks were introduced, however, it is found that efficiency of noise reduction is low because noise problem is still issued. In this study, to grasp noise characteristics on slab tracks we measured noise on high speed rail slab track in addition Saemaul and Moogungwha and the results have done comparative analysis.

• International Journal of High-Rise Buildings
• /
• v.6 no.1
• /
• pp.91-99
• /
• 2017

Special consideration should be given to differential column shortening during the design and construction of a tall building to mitigate the adverse effects caused by such shortening. The effects of the outrigger - which is conventionally used to increase the lateral stiffness of a tall building - on the differential shortening are investigated in this study. Three analysis models, a constant-section, constant-stress, and general model, are prepared, and the differential shortenings of these models with and without the outrigger are compared. The effects of connection time, sectional area, and location of the outrigger on the differential shortening are studied. The sectional area of the outrigger shows a non-linear relation in reducing the maximum differential shortening. The optimum locations of the single and dual outriggers are investigated by an exhaustive search method, and it is confirmed that a global optimum location exists. This study shows that the outrigger can be utilized to reduce the differential shortening between the interior core wall and the perimeter columns as well as to reduce the lateral displacements due to wind or earthquake loads.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.77-83
• /
• 2009

The construction of concrete slab track system is increased because the system has advantages which are maintenance free and so on, the other side, the system has weak points such as increase of the cost of the early stage construction. Recently, railway environment is issued including noise. Therefore, measures which are to mitigate noise on slab tracks were introduced, however, it is found that efficiency of noise reduction is low because noise problem is still issued. In this study, to study noise characteristics on concrete tracks we measured noise by site types. Finally the results have done comparative analysis.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.162-168
• /
• 2009

FMEA(Failure Mode and Effect Analysis) is a failure analysis method for the system to identify the potential failure modes, and their effects and causes to reduce or mitigate the critical effects of the system. FMEA for railway was introduced with reliability of railway system, and this was used for identifying and analysing the possible hazards qualitatively to meet the requirements in early stage of business. In general, the overall failure data of system could be managed from design stage by FMEA, and also the countermeasures to prevent many predicted failures could be established by identification of failure modes and assement of failure effects by FMEA. Using these advantages of FMEA, the effectiveness of reliability improvement could be expected if FMEA is applied continuously in operation stage. It is essential that railway vehicles are maintained with high level of safety and reliability not to happen any failures in operation. This paper is proposed the proper FMEA for maintenance of railway vehicles compared with existing FMEA.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.13 no.2
• /
• pp.220-220
• /
• 1999

This paper describes the high efficiency inverter ballast circuit using very cheap microprocessor, which has been developed by the author. A variety of soft-switching techniques have been proposed to reduce the switching losses and EMI problems that occur with higher switching frequencies in switched inverter ballast. The inverter ballast circuit, which employs a temperature sensing circuits has been also proposed to improve starting performance of the fluorescent lamps. That is, the inverter ballast circuit, which employs a soft-starting circuit and soft-switching techniques to implement the power factor correction and to mitigate of power-loss and increase a life time of the fluorescent lamps, has become an attractive performance for ballasting the fluorescent lamps. In this paper, the operation and the control of the inverter ballast are described in detail and experimental results are presented. As the experimental results, when environment temperature is at -40℃, the inverter ballast circuit has low THD(4.8%) of the input current and large power factor(98%) of the lamp current. The proposed improved ballast circuit appears to be a good performance for ballasting fluorescent lamps.