Huseyin Yilmaz

An approach for analysing transportation costs and a case study

One of the important parameters in the determination of optimal transportation system is economy. Therefore, a realistic method based on the technical, economical and operational parameters of various transportation modes, namely, road, railway, and sea routes is required in the analysis of costs. This method will take into consideration the probable price escalations during the lifetime of a certain transportation system. The cost of a unit of cargo or passenger per route length should be considered since it is an indicator of economics. In this paper, an approach for transportation cost analysis based on the economic analysis of the alternative modes of cargo or passenger transportation, is presented.

An Approach for Economic Analysis of Intermodal Transportation

A different intermodal transportation model based on cost analysis considering technical, economical, and operational parameters is presented. The model consists of such intermodal modes as sea-road, sea-railway, road-railway, and multimode of sea-road-railway. A case study of cargo transportation has been carried out by using the suggested model. Then, the single road transportation mode has been compared to intermodal modes in terms of transportation costs. This comparison takes into account the external costs of intermodal transportation. The research reveals that, in the short distance transportation, single transportation modes always tend to be advantageous. As the transportation distance gets longer, intermodal transportation advantages begin to be effective on the costs. In addition, the proposed method in this study leads to determining the fleet size and capacity for transportation and the appropriate transportation mode.

Evaluation of cross curves of fishing vessels at the preliminary design stage

Abstract The prediction of ship stability during the early stages of the design process is very important from the point of a vessels safety. Hence, in this study, a formula is presented to estimate cross curves of fishing vessels to predict initial stability at the preliminary design stage. For this purpose, 175 fishing vessel forms have been generated from Doust trawler hull series. The predictive technique is established by regression analysis of systematically varied fishing vessel series data. The mathematical model is constructed as a function of main design parameters such as length to beam ratio LWL/BWL, beam to draft ratio BWL/T, moulded depth to draft ratio D/T and block coefficient CB. This prediction is also used to determine the effect of specific hull form parameters and load conditions on the stability of the fishing vessel. Some basic considerations on how the proposed method can be applied to a new fishing vessel are presented.

Is It Necessary to Do Temporal Bone Computed Tomography of the Internal Auditory Canal in Tinnitus with Normal Hearing

Objective. To investigate the compression of the vestibulocochlear nerve in the etiology of the tinnitus in the normal hearing ears with temporal bone computed tomography scans. Methods. A prospective nonrandomized study of 30 bilateral tinnitus and 30 normal hearing patients enrolled in this study. Results. A total of 60 patients (ages ranged from 16 to 87) were included. The tinnitus group comprised 11 males and 19 females (mean age 49,50 ± 12,008) and the control group comprised 6 males and 24 females (mean age 39,47 ± 12,544). Regarding the right and left internal acoustic canals measurements (inlet, midcanal, and outlet canal lengths), there were no significant differences between the measurements of the control and tinnitus groups (P > 0.005). There was no narrowness in the internal acoustic canal of the tinnitus group compared with the control group. High-frequency audiometric measurements of the right and left ears tinnitus group at 8000, 9000, 10000, 11200, 12500, 14000, 16000, and 18000 Hz frequencies were significantly lower than the control group thresholds (P < 0.05). There was high-frequency hearing loss in the tinnitus group. Conclusion. There were no anatomical differences in the etiology of tinnitus rather than physiological degeneration in the nerves.

Analysis of Hearing Screening Test Findings of 11,575 Newborns in Turkey

Objectives: Review the newborn hearing screening test data performed at Corlu State Hospital, Turkey, during the last 3 years. Methods: A total of 11575 newborns that were either born in this hospital or referred from other healthcare centers between September 2009 and September 2012 were included. TEOAE (Transient Evoked Otoacoustic Emissions) test and AABR (Automated Auditory Brainstem Response) were used as screening tests. After the newborn failed the initial TEOAE test, the test was repeated after 15 days. If the same result was obtained at the second test, the newborns were referred for ear, nose, and throat (ENT) examination. TEOAE and AABR screening tests were performed as the third stage evaluation. Results: Out of 11575 newborns, 593 (5.12%) had failed the test and were referred for ENT examination and further evaluation. Out of these 593 neonates, 474 (79.93%) passed the second step test at the referral center. 106 (17.87%) did not show up again, so we did not get any information about them. Unfortunately, bilateral and unilateral sensory neural hearing impairment was detected in 12 and 3 babies, respectively. Seven of these babies had risk factors such as family history of hearing loss and consanguineous marriages. Conclusions: Newborn hearing screening and early diagnosis are an problems in our field. The final hearing impairment ratio of our study was parallel to general statistics, but our false positive ratio seemed to be higher than that of other centers. It is important to do all tests at the same center concomitantly in order to decrease the false negative ratio.