• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1997.04a
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• pp.293-300
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• 1997

This paper is concerned with the vibration control of multi-layer structure for ultra-tall buildings and main tower of large bridge etc. We have modeled the multi-layer structure with the distributed mass system as the lumped mass system of two-degree-of-freedom structure and made experimental equipment. The H$_{\infty}$ control theory is applied to the design of the control system. The designed control system is simulated by computer. As a result, the designed H$_{\infty}$ controller showed good vibration control performance to impact excitation and the good frequency response.e.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.516-528
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• 2009

Form the application of long rail system the non-ballast steel plate bridges, fatigue strength increase and rail noise reduction can be expected. This is mainly form the reduction of the rail impact at the rail joint locations which already made to behave together from welds. In the high speed rail, application of long rail system is essential because without long rail system, the required serviceability level can not be achieved. But even with this long rail systems, the thermal expansion from the girder can not be absorbed in the normal bearing systems, and these expansion cause between girder and rail. Also unexpected rail buckling and fracture through rail thermal tension may happen. It was found through numerical analysis and field measurement that these problems can be avoided by semi-fixed bearing system. In this study, the benefits of non-ballast plate bridge through long rail system, especially at the point of girder stability, girder stiffness increase and bearing maintenance will be reviewed.

• Journal of the Korean Society for Railway
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• v.4 no.1
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• pp.31-37
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• 2001

There are three examples of noise reduction test by joint improvement. One of them is tested for electric car at joint rail and another is tested at expansion joint and long welded rail and the third is tested at open deck bridge. We can know from the result that the noise reduction effect of rail welding is very different to the type of track and the car. The condition of the test has some differences, but it may be useful reference of noise reduction

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2003.09a
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• pp.93-100
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• 2003

The continuing scaling trend in microelectronic circuit technology has a significant impact on the different IC interconnection and packaging technologies. These latter technologies have not kept pace with the IC scaling trends, resulting in a so-called“interconnect technology gap”. Multilayer thin film technology is proposed as a“bridge”- technology between the very high density IC technology and the coarse standard PCB technology. It is also a key enabling technology for the realisation of true“System-in-a-Package”(SIP) solutions, combining multiple“System-on-a-Chip”(SOC) IC's with other components and also integrating passive components in its layers. A further step is to use this technology to realise new functionalities on top of active wafers. These additional“above-IC”processed layers may e.g. be used for low loss, high speed on chip interconnects, clock distribution circuits, efficient power/ground distribution and to realize high Q inductors on chip.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.04a
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• pp.284-291
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• 2002

New information technology developments continue to have a significant impact on civil engineering fields. The objective of this study is to develop STEP-based database which will be able to store and manipulate the information of steel bridges over the life cycle. In this study, there are three steps to fulfil the objective to build database and develop the application module for that data model practically and effectively To begin with, STEP methodology for a development of data model has been used for modelling data structure. And then the data model for a steel bridge's shape and structural analysis information has been made up by using AP203 (configuration controlled design) and AP203 (composite and metallic structural analysis and related design) which are the international standard in STEP Lastly, the application module for an access to information of steel bridges has been developed by means of already made database. This study show efficiently the prototype of developing information system with the existing standard technology in civil engineering fields.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.43-49
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• 2006

To design railway vehicles to ensure comfortable running, ride comfort of human exposed on vibrating carbody should be considered. Also, to improve ride comfort for passenger coach, many factors should be analysed and evaluated. There are many factors as suspension characteristics of railway vehicle, track characteristics to run etc. In this paper, passenger coach sujected to test on specific routine were evaluated using test results. Test routine were divided by 13 sections to analyse more detail. And the characteristics of every section were analysed distributions of radius curves, tunnel and bridge which could give impact to ride comfort. The evaluation of ride comfort were accomplished by UIC and ISO methods.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• v.1
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• pp.429-434
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• 2006

It is naturally to be expected that occupational stress on seafarers has specific characters compared to workers engaged in other industries. Because the physical rigors of working and living at sea has been endured as a part of job. The purpose of this paper is to figure out physical changes on seafarers resulted from ordinary shipboard life on the ocean-going cargo vessel. To do this, we performed biochemical inspections testing blood and urine for 28 crews, and measured heart rate of officers engaging in some bridge duties. The tests showed that creatinine, uric acid, total cholesterol, HDL-C, LDL-C of some crews fell down to level which could make a bad impact on human body. And the heart rate of deck officers had vibrated with rather wide amplitude whenever they have got some work-related psychological pressure.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.11
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• pp.140-148
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• 2004

Tight integration of product design and process planning in the early design stage would make bigger impact as wider spectrum of design and manufacturing alternatives can be pursued and evaluated. Thus the development of systematic computer-based supporting for this integration if desirable. For this integration and process planning in the early design stage, the systematic method to synthesize shape of part from functional requirements is crucial. This research presents the methods of functional decomposition from overall function of product and synthesizing shape of part based on functional relations extracted from functional decomposition using planetary gear transmission system as an example.

• International Journal of Computer Science & Network Security
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• v.24 no.3
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• pp.71-82
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• 2024

This paper proposes a new communication system for e-learning applications to mitigate the negative impacts of COVID-19 where the online massive demands impact the current commu-nications systems infrastructures and capabilities. The proposed system utilizes high-altitude platforms (HAPs) for fast and efficient connectivity provision to bridge the communication in-frastructure gap in the current pandemic. The system model is investigated, and its performance is analyzed using adaptive antenna arrays to achieve high quality and high transmission data rates at the student premises. In addition, the single beam and multibeam HAP radio coverage scenarios are examined using tapered uniform concentric circular arrays to achieve feasible communication link requirements.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.136-142
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• 2024

Haze is a very common phenomenon that degrades or reduces the visibility. It causes various problems where high quality images are required such as traffic and security monitoring. So haze removal from images receives great attention for clear vision. Due to its huge impact, significant advances have been achieved but the task yet remains a challenging one. Recently, different types of deep generative adversarial networks (GAN) are applied to suppress the noise and improve the dehazing performance. But it is unclear how these algorithms would perform on hazy images acquired "in the wild" and how we could gauge the progress in the field. This paper aims to bridge this gap. We present a comprehensive study and experimental evaluation on diverse GAN models in single image dehazing through benchmark datasets.