• Journal of the Korean Society of Systems Engineering
• /
• v.4 no.1
• /
• pp.31-34
• /
• 2008

As a supply contract for 100 new high-speed rolling stocks(KTX-II) was made 8th June 2006, System Engineering process has been applied to introduce the high-speed rolling stocks successfully and to manage the total life cycle systematically from Pre-concept Phase, Contract Phase, Preliminary and Critical Design Review, Production, Test and Verification, Acceptance and Operation to assurance for a flaw.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2010.11a
• /
• pp.1007-1008
• /
• 2010

• International Journal of High-Rise Buildings
• /
• v.12 no.4
• /
• pp.287-297
• /
• 2023

This paper briefly discusses current issues in wind engineering, including the enhancement of aerodynamic database and AI-assisted design, aerodynamic characteristics of tall buildings with atypical building shapes, application of computation fluid dynamics to wind engineering, evaluation of aerodynamic force coefficients based on a probabilistic method, estimation of tornadic wind speed (JEF scale) and effect of the Ekman Spiral on tall buildings.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.583-588
• /
• 2004

Opening commercial service of KTX at the time of demanding more flexible train set for HONAM line and JEONLA line, it's necessary for the Korean High speed train, performing the stabilization; to modify the design in aspect of passenger and maintenance. In order to ensure the optimized interior design in Korean High speed train, it is necessary to review the major items such as disabled passenger facility, toilet, seat arrangement, compartment partition and door, access door, electrical cabinet, color and paint through the European standard and compare with other high speed train.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.835-840
• /
• 2008

Next Generation High Speed Train having a distributed electrical motor system has just been developing to aim the experimental maximum speed at 400km/h since August, 2007. This project is in stage of concept design and so, it needs to take some review and analysis the characteristics of suspensions on the view of concept design. A vehicle modeling is made of modified Korean High Speed Train bogie model with Vampire program and analyzed the effect on the dynamic performances according to the variation of primary and secondary suspension characteristics. The results would be useful to manage the potential risks in the next stage of basic and precision design that will be done by the manufacturing company.

• International Journal of Highway Engineering
• /
• v.15 no.4
• /
• pp.177-186
• /
• 2013

PURPOSES: The purpose of this study theoretically reviews vertical grade deriving process in super high speed environment and compares overseas design criteria with Domestic Standardization also draws suitable vertical grade design criteria of high standard for Domestic Circumstances in Korea. METHODS : By researching domestic vehicle registration status, calculating typical vehicle, using Vissim which is traffic simulation program, Speed-distance curve of the vehicle is derived under each design speed condition. Through Speed-distance curve, estimating critical length of grade and considering critical length of grade, maximum longitudinal incline is proposed. RESULTS : The result of domestic vehicle registration status, the typical vehicle for deriving vertical grade is calculated based on gravity horsepower ratio 200 lb/hp. For calculating critical length of grade, according to change speed of uphill entry, speed-distance curve is derived by using Vissim. Critical length of grade is calculated based on design speed 20 km/h criteria which is point of retardation. Estimated critical length of grade is 808 m and based on this result, maximum longitudinal incline was confirmed in the design speed between 130km/h to 140km/h. CONCLUSIONS: The case of the typical vehicle(truck) which is gravity horsepower ratio 200 lb/hp, maximum longitudinal incline 2% is desirable at the super high speed environment in the design speed between 130km/h to 140km/h.

• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.1653-1661
• /
• 2008

A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. In the area of wayside structure, the stability of track structure and train run shall be evaluated through the review of impact by increased speed by developed train on track structure. The study thus was intended to evaluate the impact on track while a tilting train is running the conventional line(ballast track), which is vulnerable to accelerated train speed. The evaluation of tilting train test running the part of Honam line was conducted to identify the impact on existing track performance by tilting train. To identify the performance of each part of track components while tilting train and high speed train were running the existing line, wheel load, rail bending stress, vertical displacement of rail and sleeper were compared so as to evaluate the expected impact by tilting train for improving the train speed.

• Proceedings of the KSR Conference
• /
• 2011.10a
• /
• pp.2852-2859
• /
• 2011

Planning and construction of railway for high speed trains up to 400 km/h are recently driven in Korea. High speed train is one of the environment-friendly fastest mass transportation means but its noise generated by rolling, traction and aerodynamic mechanism can cause public complaints of residents nearby railways. To cost-effectively prevent the troublesome noise in a railway planning stage, the rational railway noise prediction method considering the characteristics of trains as well as railway structures should be required but it is difficult to find an authentic method for Korean high speed trains such as KTX and KTX-II. In this study, recent railway noise prediction methods developed by EU countries are introduced and discussed for consulting before setting the framework of our own railway noise prediction model emitted by Korean high speed trains over 250 km/h. Especially, the new Schall 03 model (2006) developed by Germany and IMAGINE model (2007) suggested by an EU framework research project are intensively reviewed. In addition, research items required for the development of our own model are suggested.

• International Journal of Highway Engineering
• /
• v.16 no.2
• /
• pp.99-106
• /
• 2014

PURPOSES : This study is to develop Right-Turning Channelization Design Models of Semitrailer at Intersections by regression of vehicle tracking simulation. METHODS : Based on the literature review, it was indicated that right-turning channelization design guide of semitrailer is too complex and is not reflected turning speed and approach angle. To verify effectiveness of right turning semitrailer trajectories according to the changing turning speed and approach angle, vehicle tracking simulation was executed. And then, simulation results were analyzed for modeling design elements; minimum turning radius, swept path width, arc length, width of triangle island, of right-turning channelization using regression methods. RESULTS : When the turning speed is getting higher, minimum turning radius, arc length, width of triangle island increased and the approach angle lower, swept path width, arc length, width of triangle island reduced. The turning radius completely reflected by turning speed. CONCLUSIONS : In this research, it was investigated how much design elements are changed according to the turning speed and the approach angle of semitrailer. The developed right-turning channelization design models can help engineers to easy and comfortable design at various conditions.

• Transactions on Electrical and Electronic Materials
• /
• v.17 no.6
• /
• pp.317-328
• /
• 2016

Over the past few decades, CMOS current comparators have been used in a wide range of applications, including analogue circuits, MVL (multiple-valued logic) circuits, and various electronic products. A current comparator is generally used in an ADC (analog-to-digital) converter of sensors and similar devices, and several techniques and approaches have been implemented to design the current comparator to improve performance. To this end, this paper presents a bibliographical survey of recently-published research on different current comparator topologies for low-power and high-speed applications. Moreover, several aspects of the CMOS current comparator are discussed regarding the design implementation, parameters, and performance comparison in terms of the power dissipation and operational speed. This review will serve as a comparative study and reference for researchers working on CMOS current comparators in low-power and high-speed applications.