• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.15-21
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• 2007

This paper proposes an improved methodology for estimating traffic accident cost savings in the transport appraisal. Four major problems from the existing framework are identified and their alternatives are suggested. First, casualties in the established approach are classified by just two types of 'killed' and 'injured'. This study supplies the indices of fatality further details. Namely, road victims are regrouped by 'killed', 'seriously injured', 'slightly injured', and 'accident reports'. Those of railways are similarly sorted by 'killed', 'seriously injured', and 'slightly injured'. Second, damage only accidents are not satisfactorily considered in the current arrangement. The accidents should be considered as one of the accident types and the social cost of them should also be evaluated. Third, the unit cost of accidents is given by the total value. The unit cost is consisted of several elements and each loss would be useful for a policy frame. This study breaks down the total figure into four pieces of costs, namely production loss, medical treatment, property loss, and administrative costs. Finally, there is inconsistency in the audit between roads and railways. Road accidents are analyzed by road types. On the other hand, patronage or others is the classification rule of rail accident costs. This paper suggests a way that the accident costs of two modes can be coherently estimated based on the level of services by each mode. The result of this study is expected to help frame more cautious social overhead capital investment policies.

• Progress in Medical Physics
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• v.16 no.2
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• pp.62-69
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• 2005

The purpose of this study has been performed to investigate the possibility of external audit program using thermoluminescence dosimetry for electron beam in korea. The TLD system consists of LiF powder, type TLD-700 read with a PCL 3 reader. In order to determine a calibration coefficient of the TLD system, the reference dosimeters are irradiated to 2 Gy in a $^{60}CO$ beam at the KFDA The irradiation is performed under reference conditions is water phantom using the IAEA standard holder for TLD of electron beam. The energy correction factor is determined for LiF powder irradiated of dose to water 2 Gy in electron beams of 6, 9, 12, 16 and 20 MeV (Varian CL 2100C). The dose is determined according to the IAEA TRS-398 and by measurement with a PTW Roos type plane-parallel chamber. The TLD for each electron energy are positioned in water at reference depth. In this study, to verify of the accuracy of dose determination by the TLD system are performed through a 'blind' TLD irradiation. The results of blind test are $2.98\%,\;3.39\%\;and\;0.01\%(1\sigma)$ at 9, 16, 20 MeV, respectively. The value generally agrees within the acceptance level of $5\%$ for electron beam. The results of this study prove the possibility of the TLD quality assurance program for electron beams. It has contributed to the improvement of clinical electron dosimetry in radiotherapy centers.