• International Journal of Railway
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• v.5 no.3
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• pp.103-113
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• 2012

Infrastructure costs could be greatly reduced if the need for bridges and tunnels was reduced, or if the line could be shortened. Tilting trains might be a less costly alternative to building new tracks with large curve radii, because tilting trains can negotiate tighter curves without having to decrease their speeds. Tracks built for tilting trains would be cheaper, as they require fewer bridges and tunnels. This paper compares the construction costs of two different options for the new Dodam-Yeoncheong section on the Central line, which includes 148.65 km of new electrified double-track with a design speed of 250 km/h. The first option is to straighten the high-speed line. The second option is to build a line with small radii curves and run tilting trains on the line. In the first option, tunnels would account for about 51% of the new section. In comparison, the second option would have shorter curves and fewer tunnels and bridges which would reduce construction costs. Furthermore, alignment modifications could be made to several segments on the straight line, making the most of the existing roadbed. The analysis concluded that the line suited to tilting trains would be 95.7 million USD cheaper to build the straight route. That is a savings of 2.8% of the total project cost. However, this option would increase the total travel time of the route by 1.2 minutes, which means it is not necessarily the best choice.

• Archives of Craniofacial Surgery
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• v.22 no.1
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• pp.45-51
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• 2021

Background: Mandibular deficiency leading to facial asymmetry causes cosmetic deformity as well as psychological stigma for the patient. Correction of these mandibular asymmetries is a major challenge. The study investigates the efficacy of bidirectional mandible distraction for the treatment of mandibular deficiency. Methods: This prospective study included six individuals aged between 17 and 24.4 years. Five patients had hemifacial microsomia and one had unilateral temporomandibular joint ankyloses. All patients underwent mandibular distraction osteogenesis. Postoperative skeletal changes in affected mandible, and changes in occlusal plane and oral commissure cant were evaluated using three-dimensional reconstruction. Patient satisfaction and understanding of the procedure were assessed through three questionnaires administered during pre-distraction, distraction and post-distraction phases. Results: In pre-distraction phase, aesthetic appearance seemed to be the primary indication for surgery. In distraction phase, pain while chewing was the primary handicap. In post-distraction phase all patients were satisfied with the aesthetic outcome. The facial deformity was improved through mandibular distraction osteogenesis. On the affected side in all the patients, height and length of the mandible increased. Canting of the occlusal plane and oral commissure was corrected. Conclusion: Bidirectional mandible distraction is an effective treatment for correction of mandible deformities in adult patients.

• Proceedings of the KSR Conference
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• 2007.11a
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• pp.940-952
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• 2007

It is found that there are many serious errors in deriving the existing governing equations of motion for a wheel-axle set negotiating an arbitrarily changing radius curve by Vijay K. Garg and Rao V. Dukkipati. Among other things, despite the hypothesis on arbitrarily changing radius of curve, there had been no taking a time derivative of the radius R in the first half of the derivation. Even if the D'lambert force arising from the centrifugal acceleration of vehicle body or bogie was appropriately taken into account while calculating cant deficiency, it is unnecessarily duplicated in the force vectors of governing equations. The graphical model given in Fig. 5.15 is not enough to follow those developed expressions from both physical and structural points of view. Besides, there are some blunders in assigning plus or minus sign not to be regarded as simple typographic ones and similar mistakes are committed in deriving creep force expressions as in the case of a wheel-axle set on a tangent track.

• Proceedings of the KSR Conference
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• 2001.05a
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• pp.289-294
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• 2001

A curved track needs balanced super elevation according to the speed of the passing train and it is limited by maximum allowable amount. Therefore, passing speed at high degree curved track has to be controlled below the limits. Accurate position of the Speed Limit Post(SLP), which shows allowable speed of curved track dose not regulated so design and line side maintenance engineer adopt the position differently, When the rate of cant deficiency is considered on transition-curved section, the SLP should be located at the beginning point of the transition curve so as to control the speed of passing train and it will increase ride quality to passenger.