• Review of KIISC
• /
• v.33 no.4
• /
• pp.7-12
• /
• 2023

디지털운행기록장치(DTG)는 차량의 운행정보를 기록하고 저장하는 장치로, 여객 및 화물자동차에 의무적으로 장착되어 여러 실시간 운행기록을 수집하고 관리할 수 있도록 하고 있다. 대부분 버스, 택시, 화물차 등에 사용되며, 상용 자동차의 운전자를 인증하고 과도한 운행으로 인한 사고를 줄이는 데 중요한 역할을 한다. 본 연구에서는 기존의 국내 디지털운행기록장치 관련 지침 및 표준 사양의 보안 기술 관련한 내용을 살펴보고 더 나아가 문헌조사를 통해 발견된 디지털운행기록장치 데이터 보호 관련 기본적 보안원칙을 소개한다. 더불어, 디지털 포렌식을 위한 데이터 식별 방법에 대한 실험적인 시도 사례의 결과를 함께 소개한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.10
• /
• pp.4762-4767
• /
• 2012

The AF track circuit that detecting train position and transmitting various train control data for DTG to the train on-board is composed of single operation system. If a failure occurs on this system, the driver should be operate the train by manually until the system is restored, because the system cannot control switch machines and signals by automatically. In this process the human error affects to the train delay, collision, derailment and critical safety accident. Therefore, this document has analyzed the effects that each failure mode influences on system and train, and quantified the failure valuation point and class. Basis on this quantified analysis result, MTBF increased and MTTR decreased and failure number also decreased by adopting the independent installation of power supply, the replacement of defected capacitors, the installation of resister cooling system and the improvement of maintenance methods. And the failure factors of AF track circuits were decreased by conducting the preventive maintenance which is a quantitative way of maintenance system by experience.

• Applied Chemistry for Engineering
• /
• v.31 no.1
• /
• pp.36-42
• /
• 2020

In order to investigate the effect of the oxidation process on thermal properties of the pitch, the oxidized pitch was prepared by changing the oxidation temperature. Thermal properties of the pitch were analyzed using thermogravimetric analysis (TGA), and it divided into three sections as A (25~100 ℃), B (250~550 ℃) and C (550~800 ℃) by derivative thermogravimetry (DTG) graph behavior. In the A section, the was reduced because the moisture contained in the pitch was removed. In the B section, as the oxidation temperature increased, the thermal stability of the pitch is improved. Because the degree of aromaticity and molecular weight of the pitch increased with increasing oxidation temperature. In contrast, the results of the C section were shown opposite of B section. Because the introduced C-OH, C-O-C, and C=O bonds were decomposed, and the resulting oxygen compounds induced the combustion reaction of the pitch.

• Fire Science and Engineering
• /
• v.20 no.4 s.64
• /
• pp.72-76
• /
• 2006

Polymer/clay nanocomposites have generated considerable interests in the past decade because adding just tiny amount of clay to the polymer matrix could produce a dramatic enhancement in physical, thermal and mechanical properties. Smectite clays, such as montmorillonite (MMT), are of great industrial value because of their high aspect ratio, plate morphology, intercalative capacity, natural abundance and low cost. In this study, PE/MMT nanocomposites were directly prepared by melt intercalating PE and the modified clay. The nanostructure was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their flame retardant properties were measured and discussed by limiting oxygen index (LOI), char yield and smoke mass concentration. And their thermal stabilities were measured by differential thermogravimetric (DTG) and thermogravimetric analysis (TGA). The PE/MMT nanocomposites proved more effective the conventional composites in reinforcement. Two functions in the thermal stability of the PE/MMT nanocomposite, one is the barrier effect to improve the thermal stability, and another is catalysis, leading to a decrease of the thermal stability. The flammability was greatly decreased due to the formation of the clay-enriched protective char during the combustion.

• The Journal of Natural Sciences
• /
• v.1
• /
• pp.47-59
• /
• 1987

The thermal decomposition mechanism of BaTiO($$C_2$$O_4$)_2$ $4H_2$O has been investigated employing TG, DTG, and DTA techniques. The intermediate compounds and the gaseous products of decomposition were examined by IR spectrometer and X-ray analyser. The decomposition proceeds through five steps. The first step which is the dehydration of the tetrahydrate is followed by the decomposition of oxalate groups. During the second decomposition, half a mole of carbon monoxide is evolved. The oxalate groups are completely destroyed in the range $260~460^{\circ}C$, resulting in the formation of a carbonate which retains free carbon dioxide in the matrix . the final decomposition of the carbonate takes place between $650~750^{\circ}C$ and yields $BaTiO_3$.

• Journal of Powder Materials
• /
• v.27 no.6
• /
• pp.490-497
• /
• 2020

The 3D printing process provides a higher degree of freedom when designing ceramic parts than the conventional press forming process. However, the generation and growth of the microcracks induced during heat treatment is thought to be due to the occurrence of local tensile stress caused by the thermal decomposition of the binder inside the green body. In this study, an alumina columnar specimen, which is a representative ceramic material, is fabricated using the digital light process (DLP) 3D printing method. DTG analysis is performed to investigate the cause of the occurrence of microcracks by analyzing the debinding process in which microcracks are mainly generated. HDDA of epoxy acrylates, which is the main binder, rapidly debinded in the range of 200 to 500℃, and microcracks are observed because of real-time microscopic image observation. For mitigating the rapid debinding process of HDDA, other types of acrylates PETA, PUA, and MMA are added, and the effect of these additives on the debinding rate is investigated. By analyzing the DTG in the 25 to 300℃ region, it is confirmed that the PETA monomer and the PUA monomer can suppress the rapid decomposition rate of HDDA in this temperature range.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.6
• /
• pp.1-6
• /
• 2020

Road movement pollutant air environment big data is a link between real-time traffic data such as vehicle type, speed, and load using AVC, VDS, WIM, and DTG, which are always traffic volume survey equipment, and road shape (uphill, downhill, turning section) data using GIS. It consists of traffic flow data. Also, unlike general data, a lot of data per unit time is generated and has various formats. In particular, since about 7.4 million cases/hour or more of large-scale real-time data collected as detailed traffic flow information are collected, stored and processed, a system that can efficiently process data is required. Therefore, in this study, an open source-based data parallel processing performance optimization study is conducted for the visualization of big data in the air environment of road transport pollution.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.6
• /
• pp.107-117
• /
• 2020

With the recent development of autonomous vehicles, various sensors installed in vehicles have become common, and big data generated from those sensors is increasingly being used in the transportation field. In this study, we proposed a grid index method to efficiently process real-time vehicle sensing big data and public data such as road weather. The applicability and effect of the proposed grid space division method and grid ID generation method were analyzed. We created virtual data based on DTG data and mapped to the road link based on coordinates. As a result of analyzing the data processing speed in grid index method, the data processing performance improved by more than 2,400 times compared to the existing link unit processing method. In addition, in order to analyze the efficiency of the proposed technology, the virtually generated data was mapped and visualized.

• Smart Media Journal
• /
• v.12 no.8
• /
• pp.26-36
• /
• 2023

The purpose of this study is to propose ways to revitalize the local economy by analyzing the index changes and tourism big data before and after the opining of the KTX on the Gangneung Line in Gangneung City, where the population continues to decline. For This, the main current status of Gangneung-si and internal operation record data(DTG) of Gangneung-si were analyzed. After that, changes in the movement behavior of public transportation users before and after the opening of the KTX Gangneung Line were compared. As a result, it was possible to observe changes in tourist transportation preferences, demographic shifts, alterations in small-scale business sectors and in the travel patterns of tourists within the city of Gangneung. In particular, changes in the small business sector have shown an increase in general restaurants, leisure food establishments(cafes, etc.), and accommodation facilities following the opening of the KTX Gangneung Line. All three sectors have experienced growth concentrated in the vicinity of Gangneung Station, indicating the influence of Gangneung Station, which opened in the central part of Gangneung city, following the inauguration of the KTX Gangneung Line.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.22 no.6
• /
• pp.141-156
• /
• 2023

This study aims to improve understanding of freight movement, crucial for logistics facility investment and policy making. It addresses the limitations of traditional freight truck traffic data, aggregated only at city and county levels, by developing a new methodology. This method uses trip chain data for more detailed, facility-level analysis of freight truck movements. It employs DTG (Digital Tachograph) data to identify individual truck visit locations and creates H3 system-based polygons to represent these visits spatially. The study also involves an algorithm to dynamically determine the optimal spatial resolution of these polygons. Tested nationally, the approach resulted in polygons with 81.26% spatial fit and 14.8% error rate, offering insights into freight characteristics and enabling clustering based on traffic chain characteristics of freight trucks and visited facility types.