• Transactions of the Korean Society of Automotive Engineers
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• v.23 no.6
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• pp.615-622
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• 2015

Recently Digital-TachoGraph(DTG) was mounted mandatorily in commercial vehicles(Taxi, Bus, etc.). DTG records accurate and detailed information of the running state of vehicles related to traffic accident, such as Time, Distance, Velocity, RPM, Brake ON/OFF, GPS, Azimuth, Acceleration. Thus those standardized data can play an important role in traffic accident investigation and reconstruction. To develope the accurate and objective method using the DTG data for the reconstruction of traffic accident, we had conducted several tests such as driving test, high speed circuit test, braking test, slalom test at Korea Automobile Testing & Research Institute(KATRI), and collision test at Korea Automobile insurance repair Research and Training center(KART) with the vehicle equipped with several DTG. Development of the program which enables the reading and analysis of the DTG data was followed. In the experiments, we have found velocity error, RPM error, brake signal error and azimuth error in several products, and also non-continuous event data. The cause of these errors was deduced to be related to the correction factor, the durability of electronic parts and the algorithm.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 1999.05a
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• pp.53-57
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• 1999

본 논문에서는 입출력간의 연관관계가 트리구조로 표현되는 DTG(Directed tree graph)에 의한 고속병렬다치논리회로를 설계하는 알고리즘과 DTG의 각 절점에 코드를 할당하는 알고리즘을 제안한다. 임의의 절점을 갖는 DTG에 대하여 본 논문에서는 절점들이 매개변수에 의하여 표현될 때 양의 정수로 표현되도록 논리레벨 P를 할당하고 각 레벨에 각기 다른 잉여절점을 추가하여 회로를 설계한다. 또한, 절점들의 입출력 관계를 단지 하나의 매개변수 m$_{i}$를 이용하여 전달행렬 A를 구하기 때문에 더 빠르고 간단하게 회로를 설계할 수 있다. 본 논문에서 제안한 알고리즘은 Nakajima 등에 의해 제안된 알고리즘으로는 설계가 가능하지 않았던 임의의 절점을 가지는 DTG에 대해서도 회로를 설계할 수 있는 장점이 있다. 또한, 자연수 내에서 선형성, 정규성, 및 가시적인 장점을 가지며 절점수의 감소를 통한 처리속도의 향상, 회로 구성의 간략화 및 비용절감등의 장점등이 있다.

• Journal of Institute of Control, Robotics and Systems
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• v.3 no.3
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• pp.311-317
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• 1997

DTG(dynamically tuned gyroscope) is a sensor detecting disturbance in angle velocity control loop of EOTS(electro optical tracking system), which is used for the stabilization of gimbal. DTG is classified into rate mode or rate integrated mode according to operating mode. In this paper, basic principles and characteristics of DTG, depending on to operating mode, are compared and the model of rate integrated mode DTG is proposed. Also, the validity of the presented model is verified by computer simulations and experiments.

• Transportation Technology and Policy
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• v.12 no.5
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• pp.28-33
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• 2015

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.6
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• pp.907-916
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• 2018

This study presents a methodology that can integrate the information generated by the Busan taxi DTGs and Tachometers. Utilizing the results by the methodology, travel patterns of taxi users were analyzed. Also to verify the reliability of the methodology was conducted by comparing its results with those of O-D information of the National Transportation DB (KTDB). Despite the limited number of samples. the results of this study showed that DTG data, which can reflect changes in status and conditions in real time, can be used as a replacement for KTDB. It is expected that the results generated by the suggested methodology can be useful for developing and executing desirable taxi related policies.

• Journal of Korean Society of Transportation
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• v.35 no.2
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• pp.160-168
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• 2017

In the past 10 years, the accidents caused by drowsy driving have occupied about 23% of all traffic accidents in Korea expressway network and this rate is the highest one among all accident causes. Unlike other types of accidents caused by speeding and distraction to the road, the accidents by drowsy driving should be managed differently because the drowsiness might not be controlled by human's will. To reduce the number of accidents caused by drowsy driving, researchers previously focused on the spot based analysis. However, what we actually need is a segment (link) and occurring time based analysis, rather than spot based analysis. Hence, this research performs initial effort by adapting link concept in terms of drowsy driving on highway. First of all, we analyze the accidents caused by drowsy in historical accident data along with their road environments. Then, links associate with driving time are analyzed using digital tachograph (DTG) data. To carry this out, negative binomial regression models, which are broadly used in the field, including highway safety manual, are used to define the relationship between the number of traffic accidents on expressway and drivers' behavior derived from DTG. From the results, empirical Bayes (EB) and potential for safety improvement (PSI) analysis are performed for potential risk segments of accident caused by drowsy driving on the future. As the result of traffic accidents caused by drowsy driving, the number of the traffic accidents increases with increase in annual average daily traffic (AADT), the proportion of trucks, the amount of DTG data, the average proportion of speeding over 20km/h, the average proportion of deceleration, and the average proportion of sudden lane-changing.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.5
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• pp.72-84
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• 2017

Together with the Big Data of the 4th Industrial Revolution, the traffic information system has been changed to an section detection system by the point detection system. With DTG(Digital Tachograph) data based on Global Navigation Satellite System, the properties of raw data and data according to processing step were examined. We identified the vehicle trajectory, the link travel time of individual vehicle, and the link average travel time which are generated according to the processing step. In this paper, we proposed a application method for traffic management as characteristics of processing data. We selected the historical data considering the data management status of the center and the availability at the present time. We proposed a method to generate the Travel Time Index with historical link average travel time which can be collected all the time with wide range. We propose a method to monitor the traffic congestion using the Travel Time Index, and analyze the case of intersections when the traffic operation method changed. At the same time, the current situation which makes it difficult to fully utilize DTG data are suggested as limitations.

• Journal of the Korean Magnetics Society
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• v.6 no.1
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• pp.48-53
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• 1996

The role of the torquer in dynamically tuned gyroscope (DTG) is to erect the slanted rotor straight. This IBper presents the design method of the torquer. The torquer must satisfy the desired maximum angular velocity condition. The performance of magnet-residual flux density, maximum energy product, and so on-is limited by the material characteristics. So we should design the torquer with the limited condition that magnet performance is given. If the mechanical size of DTG is deter-mined, the dimension of the torquer is calculated and the space of the torquer becomes constant. Therefore, if we determine the diameter of the torquer coil, the number of coil turns is calculated automatically. Using these dimensions, we can calculate the torque and the scale factor. The maximum angular velocity is computed if we know the maximum current density. The analysis of the torquer was carried out by the 3-dimensional finite element method. The proposed algorithm of the torquer design was valid in comparison with the experimental data obtained from fabricated DTG.

• Journal of Auto-vehicle Safety Association
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• v.14 no.1
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• pp.26-31
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• 2022

Changwon City has the second highest accident rate with 79.6 according to the city bus accident rate. In fact, 250,000 people use the city bus a day in Changwon, The number of accidents is increasing gradually. In addition, a recent fire accident occurred in the engine room of a city bus (CNG) in Changwon, which has gradually expanded the public's anxiety. In the case of business vehicles, the government conducts inspections with a short inspection cycle for the purpose of periodic safety inspections, etc., but it is not in the monitoring stage. In the case of city buses, the operation records are monitored using Digital Tacho Graph (DTG). As such, driving records, methods, etc. are continuously monitored, but inspections are conducted every six months to ascertain the safety and performance of automobiles. It is difficult to identify real-time information on automobile safety. Therefore, in this study, individual automobile management solutions are presented through machine learning techniques of inspection results based on driving records or habits by linking DTG data and Vehicle Inspection Management System (VIMS) data for city buses in Changwon from 2019 to 2020.

• Transactions on Electrical and Electronic Materials
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• v.4 no.2
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• pp.15-19
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• 2003

In this paper, the new dual trench gate Emitter Switched Thyristor (DTG-EST) is proposed for improving snap-back effect which leads to a lot of serious problems of device applications. Also the parasitic thyristor that is inherent in the conventional EST is completely eliminated in this structure, allowing higher maximum controllable current densities for ESTs. The conventional EST exhibits snap-back with the anode voltage and current density 2.73V and 35A/$\textrm{cm}^2$, respectively. But the proposed DTG-EST exhibits snap-back with the anode voltage and current density 0.96V and 100A/$\textrm{cm}^2$, respectively.