• Proceedings of the KSR Conference
• /
• 2008.06a
• /
• pp.603-609
• /
• 2008

Nowadays, double-system of TFM(Track-side Functional Modules) developed instead of single-system in use of high speed line to acquisition more availability. Safety Law for Railroad recommend to quality certification of development and general railway machines. It is important to select metrics which form the bases for testing software products. A number of package software development part do not open source cords, so testing external characteristic vectors having relationship with metrics. In this paper, review the process for the TFM Point Modules, Universal Modules and Switchers, think about the test methode of circuit boards output performance by using TFM tester and Simulators.

• IE interfaces
• /
• v.16 no.spc
• /
• pp.111-115
• /
• 2003

Railroad system is consisted of resources of rail track, signal system, and vehicles. Railway operation must use these limited resources and maximize resource utilization. Line capacity(number of trains throughput/day) is determined by such as parameters, line utilization rate($\alpha$), dummy rate for the break-through hour($\beta$), and dummy rate for the number of rail track intervals($\delta$). Line capacity simulation(LCS) determined the line capacity through simulation given $\alpha$, $\beta$, and $\delta$. This paper deals with the development of parameter evaluation simulation(PES). PES presents the decision maker with the relationship of line capacity and measurement of robustness for various scenarios in different parameters and then the decision maker can determine the appropriate parameters.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.7 no.1
• /
• pp.28-35
• /
• 2007

This paper presents a high-speed flash analog-to-digital converter (ADC) for ultra wide band (UWB) receivers. In this flash ADC, the interpolating technique is adopted to reduce the number of the amplifiers and a linear and wide-bandwidth interpolating amplifier is presented. For this ADC, the transistor size for the cascaded stages is inversely scaled to improve the trade-off in bandwidth and power consumption. The active inductor peaking technique is also employed in the pre-amplifiers of comparators and the track-and-hold circuit to enhance the bandwidth. Furthermore, a digital-to-analog converter (DAC) is embedded for the sake of measurements. This chip has been fabricated in $0.13{\mu}m$ 1P8M CMOS process and the total power consumption is 113mW with 1V supply voltage. The ADC achieves 4-bit effective number of bits (ENOB) for input signal of 200MHz at 5-GSample/sec.

• Journal of the Korean Geotechnical Society
• /
• v.34 no.9
• /
• pp.33-42
• /
• 2018

When an off-road tracked vehicle travels, an engine thrust that is transmitted to the continuous track induces a shearing action on the soil-track interface. Consequently, the relative displacement known as slip displacement takes place on the soil-track interface, which develops an associated soil thrust acting as a traction force. For the loose or soft ground conditions, an excessively large slip displacement can be required for the development of the desired soil thrust which will make the tracked vehicle mobile and therefore the outer surface of the continuous track is generally designed to protrude with grousers. This paper fundamentally studied the effect of grousers on the soil thrust of off-road tracked vehicles. Based on the soil-track interaction theory, a new soil thrust assessment method that properly takes into account the effect of grousers was developed. Also, the soil thrust of off-road tracked vehicles equipped with a number of grousers was evaluated using the developed assessment method. The results showed that grousers increased the soil thrust of the continuous track, enhancing the overall tractive performance of off-road tracked vehicles. These effects were more obvious as the height of grouser increased and the spacing of grouser decreased; thus, it is concluded that the grouser which has smaller shape ratio (span of the grouser to a grouser height) significantly enhances off-road tracked vehicle's performance.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2000.04a
• /
• pp.167-170
• /
• 2000

Recently the sub-micron structured substrates of 0.74 ${mu}ell$ track pitch and 800 $\AA$groove depth are required for DVD-RAM and the track pitch is expected to be narrower as the need for the information storage density is getting higher. For the accurate replication of the land-groove structure in the stamper to the plastic substrates it is important to control the injection -compression molding process such that the integrity of the replication for the land-groove structure is maximized. in the present study polycarbonate substrates were fabricated by injection comression molding and the land-groove structure regarded as one of mold temperature and the compression pressure on the integrity of the replication were examined experimentally. An efficient design methodology using the response surface method (RSM) the central composite design(CCD) technique and the analysis-of-variance (ANOVA) was developed to obtain the optimum processing conditions which maximize the integrity of the replication with a limited number of experiments.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.1519-1524
• /
• 2009

Construction of high-speed concrete track embankments over soft ground needs many of the ground improvement techniques. Drains, surcharge loading, and geosynthetic reinforcement, have all been used to solve the settlement and embankment stability issues associated with construction on soft soils. However, when time constraints are critical to the success of the project, another measures should be considered. Especially, since the design criteria of residual settlement is limited as 30mm for concrete track embankment, it is very difficult to satisfy this allowable settlement by using the former construction method. Pile net method consist of vertical columns that are designed to transfer the load of the embankment through the soft compressible soil layer to a firm foundation and one or more layers of geosynthetic reinforcement placed between the top of the columns and the bottom of the embankment. In this paper, three cases with different embankment height and number of geosynthetic reinforcement, were studied through FEM analysis for efficient use of pile net method.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.67 no.12
• /
• pp.1735-1742
• /
• 2018

The number of electric railway failures will increase due to the external and internal effects of electric railroads. The grounding test with 25,000V is to artificially test the transmission voltage to ground, and it is possible to cause risks of electric shock and other equipment insulation damage in neighboring enclosure. In 2016, method of fault localization changed to low - voltage at 380V from artificially high- voltage in the grounding tests since opening of Seoul Metropolitan Express Railway; The method is more accurate and safer rather than the previous one because it gets more data from unlimited grounding tests. However, an electric current falls on the track section where the track branches and vehicle bases with many lines. To precisely detect a transitive phenomenon, it is necessary to continuously study and additionally install.

• International Journal of Precision Engineering and Manufacturing
• /
• v.9 no.2
• /
• pp.3-7
• /
• 2008

Vibratory conveyors are widely used in industry to transport granular materials and products. A theoretical point mass model for vibratory conveying was studied. The results agreed well with experimental observations. The model theory included the resting, sliding and flight states of the material. Each state was considered separately when determining the equations of motion. For the coefficients of restitution, values of zero for the normal component and 0.8 for the tangential component were found to be appropriate for modeling the collisions of the granular particles with the conveying surface. The vibration angle had a large influence on the mode and rate of transport. There was an optimum vibration angle for a given set of conditions. The optimum vibration angle decreased and was better defined as the coefficient of friction increased. The results suggest the existence of an optimum dimensionless track acceleration (throw number), which does not support general industrial practice in which the track acceleration is limited when the feed cycle becomes erratic and unstable.

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.501-506
• /
• 2004

This paper aims to suggest the feasibility of rapid operation scheme generated in preceding study, 'A study on development of operation planning for rapid service in urban railway(An introduction)' through application it to present subway lines in Seoul Metropolitan area. In case of line 3, without the Passing Track 'Turning train outstrip mode' is the best policy. In case of line 4, with the Passing Trank 'Passing track mode' may be the best way to realize the this scheme. Also, there is feasibility in the line 1, line 5, line 6, line 7 but there is no possibility it is applied to line 2 and line 8. In conclusion, this paper is intend to suggest the possibility of rapid operation in urban railway by presenting real operation scheme, time tables and amount of power usage and the number of composing trains and variety of demand,

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.1104-1109
• /
• 2002

High speed railroad noise is one of the main causes of environmental impact. An estimate of the relevant noise levels is usually required in order to evaluate the noise barrier and the anti-noise trailer. This paper introduce the test procedure and the estimate for HST noise. The aim of this is to measure, by means of a test, the level of acoustic pressure present during the passing of a KTX(Korea Train Express), in order to satisfy the contractual requirements and the noise criteria. A number of measurements are carried out in order to estimate noise impact by HST along test track.