• Journal of the Korean Society for Railway
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• v.18 no.3
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• pp.212-222
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• 2015

The characteristics of noise emission from tram systems should be investigated in order to design and construct an urban tram network that raises fewer environmental noise problems. In this paper, the characteristics of rolling noise from a tram were studied and a desired stiffness of the rail supports was proposed using a noise prediction model. The mobilities of embedded rails and resilient wheels were predicted using the Timoshenko beam model and the finite element model, respectively. The predicted mobilities were compared with the measured results. Compared with the measured values, the calculated noise level near the track showed small errors for frequencies higher than 300 Hz. Then, the source strengths of rail and wheel components were examined by varying the rail supporting stiffness and the slab supporting stiffness so that suitable stiffness values could be estimated that would reduce noise radiated from rails and wheels but that would not greatly increase the ground vibration.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.494-502
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• 2011

Bimodal tram is designed to run on a dedicated path in automatic mode using a magnetic track system in order to realize a combination of the accessibility of a bus and the constant regularity of a railroad. This paper presents design and test results of the series hybrid propulsion system of the bimodal tram on both test track and public road, which uses CNG (Compressed Natural Gas) engine and Lithium polymer battery pack. This paper describes the real-time data measuring equipment for the series hybrid propulsion system of the bimodal tram. Using this measurement equipment, the performance of the prototype vehicle's driving on test track and public road was verified and the fuel consumption and the efficiency of CNG engine have been investigated.

• Archives of Plastic Surgery
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• v.50 no.4
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• pp.354-360
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• 2023

Background The Island transverse rectus abdominis musculocutaneous (TRAM) flap is well vascularized with very reliable blood flow, because all perforators of the zone I are included when it is harvested. The number of perforators, topographic mapping, and their relationship with reconstructed outcomes were investigated. Methods Fifty patients with Island TRAM breast reconstruction from September 2021 to August 2022 were investigated. The zone I was divided into a total of eight sections. Under the loupe magnification, all perforators larger than 0.5 mm in zone I were counted with fine dissection, and photographs were taken in background of vessel loops. Complications like flap necrosis, seroma, and hematoma were also investigated. Result There are 12 ideal perforators on average in zone I such as one perforator in section I, II, IV, V, VI, VIII, and three perforators in section III and VII. However, two perforators (M6 and L6) below arcuate line were sacrificed in the time of flap harvest to prevent hernia. Island TRAM included 10 perforators on average (5 perforators in each side) above arcuate line to be transferred to the recipient site. Only minor complications were identified. Conclusion The Island TRAM flap includes 10 perforators to get the vigorous blood flow. The periumbilical to upper medial perforators become more dominant in the perfusion of the flap after deep inferior epigastric artery division. Well preserved perforators will guarantee the satisfactory breast reconstruction with the least complication.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.4
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• pp.513-518
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• 2024

When introducing a new policy or technology, it is common for both opposing and approving opinions to exist. In particular, identifying factors that influence opposing opinions can be the first step to successfully introducing new policies or technologies. The purpose of this study is to identify the factors affecting the acceptability of tram, a new transportation mode, in urban areas of Jeju. For this purpose, a survey was conducted on 326 Jeju residents and 104 tourists for eight days, and the surveyed data was analyzed for the main factors affecting acceptability using structural equation modeling (SEM). As a result, it was found that the higher the recognition of tram operation characteristics, the more positive the acceptability. In particular, while tram operation in downtown Jeju was evaluated positively from the perspective of the convenience of using public transportation and the urban environment, it was evaluated negatively from the perspective of traffic crashes, congestion, and pedestrian safety due to traffic conflicts. These results are expected to be used as a basis for establishing policies to successfully adopt trams in Jeju City in the future.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.78-81
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• 2011

Generally, vehicle is insulated from the earth by rubber tire which is intrinsically the insulation material. The electrical ground of vehicle was floated in the sense of electric potential over the electric power sources. First of all, the floated electrical ground of vehicle should be equipotentially connected with the (-) line of electrical equipment. Bimodal tram has the different kinds of electric system. They must be kept insulated to each other electrically. When there is some unbalanced event or connection between them, it will invoke some errors or breakdown to electrical devices including sensors and actuators. This paper has investigated the floating ground effect of bimodal tram built with composite body and shown the effect according to the unbalanced ground of vehicle and the connection between different electric systems.

• Proceedings of the KSR Conference
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• 2011.05a
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• pp.301-306
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• 2011

The rear of the vehicle generally overhangs the rear axle. As a result, the rear of a vehicle swings to the outside of the rear axle(rear swing-out). In front steering vehicles, rear swing-out is not important because rear swing-out values measured outside the rear edge are relatively small. However, in the case of the bimodal tram with AWS(all wheel steering), the rear swing-out values increase because of the rear steering at a reverse phase angle. Off-tracking is defined as the radial offset between the path of the centerline of the front axle and the path of the centerline of the following axle. In this paper, in addition to determine the turning performance of bimodal tram with AWS, turning radius, swing-out, off-tracking and swept path width were also investigated.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.57-61
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• 2011

The bimodal tram was designed to drive on the dedicated track as well as on the public road. The position and speed are automatically controlled on the dedicated track by the onboard computer, whereas they are manually controlled by driver like motor vehicles on the public road. The ride comfort the passengers feel and the effect of the vibration generated during driving on the passenger's health, comfortableness and motion sickness were evaluated with driving the bimodal tram prototype in automatic and manual mode, respectively. The test was done in automatic mode on the test track with various load conditions while it was done in manual mode on the public road with empty load.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.51-56
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• 2011

The train travels on the track and, thus, the rear wheels precisely follow the paths of the front wheels. On the contrary, in the vehicles running on the road like automobiles, buses and trucks, the front wheels try to drag the rear ones toward them and across the inside of the curve. Off-tracking is defined as the radial offset between the path of the centerline of the front axle and the path of the centerline of the following axle. In the case of the bimodal tram with AWS(all wheel steering), the off-tracking decrease but the rear swing-out values increase because of the rear steering at the reverse phase angle. Thus, in order to determine the swept path width, maximum road width at the minimum turning radius, off-tracking and swing-out should be considered for the bimodal tram. In this paper, trajectory simulations were carried out for the various condition such as front steering, front and rear steering and suppression of swing-out to optimize the swept path width.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.571-588
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• 2011

With the development of the technology, the usage of the car has been increased to the allowed limit of the road and has caused global warming and air pollution. Subway is good transit system with punctuality, safety and eco-friendliness, but it needs relatively much money for construction considering the needs of transit. So it is hard to balance the finance. Many developed countries have adopted advanced transit system including tram for the linking small and medium sized cities after 1980s, due to the relatively low construction cost. This paper reviews the way to increase the role of tram which is planed to be introduced to the local governments as a kind of Advanced transit system.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.2192-2193
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• 2011

VCU(Vehicle Control Unit) was developed to decrease the wire weight and make it easy to control the power of ECU in bimodal tram. VCU consists of CC(Central Computer), DU(Display Unit), TU(Terminal Unit) with PCB. CC is a main controller with progamming and DU displays the status with graphic symbols and letters. TU with PCB inputs and output the voltage controlled by CC. They communicate with CAN(Controller Area Network). VCU had been verified with software reliability verification test and environmental hardware test. This paper has shown the test results and application to bimodal tram.