• Journal of Internet of Things and Convergence
• /
• v.5 no.2
• /
• pp.33-39
• /
• 2019

Entering the 4^th industrial revolution, many technologies are developing and various threats are emerging. In order to cope with such threats, research is being conducted in many fields. Even in the development of various fields, the threats caused by the development of medical technology and intelligent vehicles are the threats to life due to misinformation about medical care and the threats to life by preventing the safe operation of people through intelligent vehicles. In this paper, as the patient's information is important, the private blockchain is used to increase the safety, efficiency, and scalability of the patient's medical records. We propose an information protection technique using blockchain technology to hack the car system and threaten the driver's life, solve privacy problems by identifying personal information and differences, and prevent forgery in the Internet of Things.

• Journal of the Society of Disaster Information
• /
• v.7 no.4
• /
• pp.259-265
• /
• 2011

After the commercial opening of the KTX in 2005, the high speed railroad has been rapidly emerged as the major transportation means due to its high energy efficiency. Recently, the government has announced its plan to build the future transportation system around the high speed railroad. Based on this policy, the existing lines as well as the lines under construction or design are planning to increase design speed. In this paper, the suitability of the mid-span PSC girder bridges for the high speed railroad is evaluated via dynamic analysis. IT, Precom, and WPC girder bridges are considered for the purpose of this study and, for comparison, the identical modeling method and the analysis technique are utilized. The performance indices used for dynamic performance evaluation are the natural frequency, the vertical displacement, the end axial displacement, track irregularity, etc. The KTX train is utilized as a dynamic load, and the dynamic analysis is performed up to the train speed of 420km/hr with the increment of 10km/hr.

• Journal of the Korean Society for Railway
• /
• v.15 no.2
• /
• pp.179-184
• /
• 2012

Environmental impact is getting more attention in many feasibility studies for railroad-related projects and research items. For sustainable growth and green transportation, the benefits typically used for feasibility studies in railway-related projects, are composed mostly of economic criterions which is not considering growing attention on changing paradigm. Based on the analysis of current methodologies, improvements in estimating environmental impact especially on noise and pollution are suggested. Active steering bogie has been proposed to satisfy stabilizing and steering performance of railroad. This paper describes the feasibility study of the active steering bogie for a urban railway vehicle based on environment-related criteria.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1567-1572
• /
• 2012

An IPC(instrument panel Cluster) is a useful device that provides driving information to the driver. The information includes the vehicle speed, RPM, mileage, etc. The traditional IPC has been mostly implemented with mechanical technique. According to increment of needs for the convenience of IPC by user, the IPC must provide graphical interface and efficient driving information. Also the user-friendly IPC is needed by drivers. Thus flexible and robust software structure and development methods are required in order to develop IPC. In this paper, we propose software architecture and design method for the IPC using modeling method. We use MVC model and UML to model software architecture because they have flexible and robust characteristics. We can develop the various forms of information screen by separating views from model by using state diagram and class diagram in UML. Through this, the cost saving and ease of maintenance can be expected. The development time and cost can be reduced by using proposed method.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1321-1326
• /
• 2012

An IPC(instrument panel Cluster) is a useful device that provides driving information to the driver. The information includes the vehicle speed, RPM, mileage, etc. The traditional IPC has been mostly implemented with mechanical technique. According to increment of needs for the convenience of IPC by user, the IPC must provide graphical interface and efficient driving information. Also the user-friendly IPC is needed by drivers. Thus flexible and robust software structure and development methods are required in order to develop IPC. In this paper, we propose software architecture and design method for the IPC using modeling method. We use MVC model and UML to model software architecture because they have flexible and robust characteristics. We can develop the various forms of information screen by separating views from model by using state diagram and class diagram in UML. Through this, the cost saving and ease of maintenance can be expected. The development time and cost can be reduced by using proposed method.

• Journal of Korean Society of Transportation
• /
• v.25 no.4
• /
• pp.123-133
• /
• 2007

This study analyzed whether a transit network with hierarchy is efficient or not, and if transit network hierarchy has cost efficiency, then which condition guarantees the efficiency of the transit network hierarchy. The authors modeled the total cost of the transit network and suggested the conditions in which the transit network hierarchy has cost efficiency through comparing the cost of the transit network with and without hierarchy. The efficiency of transit network hierarchy is guaranteed when the travel cost savings induced by using a higher hierarchy transit network is larger than the increasing non-travel cost, which is the sum of access cost, waiting cost, and operating cost, induced by the introduction of a higher hierarchy transit network. This result is consistent with common sense and with the concept of cost and benefit analysis. If a passenger traveling within the area divided by a higher hierarchy transit network uses only a lower hierarchy transit network and the passenger traveling out of the area divided by the higher hierarchy transit network uses both lower and higher hierarchy transit networks, the travel demand using the higher hierarchy transit network is inversely proportional to the square of the line spacing. This means that the transit network becomes more efficient and small increases of travel demand guarantee the efficiency of the transit network hierarchy as the connectivity of the network becomes higher. This result shows that transit networks have economies of aggregation. This study is the first analytical research on transit network hierarchy and is expected to be a basis for numerical research. However, numerical research should complement this study, since analytical research has some limitations for considering a real network.

• Journal of the Korean Society for Nondestructive Testing
• /
• v.35 no.4
• /
• pp.245-250
• /
• 2015

To verify the possibility of generating rattling noise from a motor on caliper brake system, a test was conducted using a caliper excited with vibrations similar to that in a vehicle running on actual roads; this test was conducted using a quiet shaker installed in an anechoic room. After several hours of external excitation, the test assembly was loosened, and the frequency of rattling noise generation increased. A microphone was used to record the generated noise. The measured signals were analyzed by conventional spectrum analysis. Since the noise is generated as an impact response, the advantages of employing Prony analysis was discussed, and the results were compared to those obtained using conventional fast Fourier transforms. The accuracy of Prony analysis was through endurance tests on different brake systems.

• Proceedings of the KSR Conference
• /
• 2009.05a
• /
• pp.284-290
• /
• 2009

As the increased importance is placed on the new transit systems owing to the environmental pollution caused by the road traffic congestion, the policy for the introduction of the new transit systems as an alternative solution to ease the heavy burden of the construction expenses is being actively established. Since the explicit recognition of such transit systems and the review on the method of its adoption have been a pressing matter in the light of reducing the pending traffic congestion, the development of the rolling stock systems in modes of new transportation has been made in various ways taking into consideration the regional circumstances to alleviate traffic congestion, and offer a more efficient service with the application of their intrinsic characteristics. Such systems also have been developed as a mix of punctuality for railway systems operating on the runway and flexibility for buses. This paper, therefore, deals in more detail with 3 modes of systems such as low-floor articulated buses, GRT(Guided Rapid Transit) and tram cars, and studies the overseas cases of the operation of those systems involving both negative and positive aspects.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.19 no.5
• /
• pp.82-96
• /
• 2020

The Demand Responsive Transit (DRT) system is the flexible public transport service that determines the route and schedule of the service vehicles according to users' requests. With increasing importance of public transport systems in urban areas, the development of stable and fast routing algorithms for DRT has become the goal of many researches over the past decades. In this study, a new heuristic method is proposed to generate fast and efficient routes for multiple vehicles using demand clustering and destination demand priority searching method considering the imbalance of users' origin and destination demands. The proposed algorithm is tested in various demand distribution scenarios including random, concentration and directed cases. The result shows that the proposed method reduce the drop of service ratio due to an increase in demand density and save computation time compared to other algorithms. In addition, compared to other clustering-based algorithms, the walking cost of the passengers is significantly reduced, but the detour time and in-vehicle travel time of the passenger is increased due to the detour burden.

• Proceedings of the KIPE Conference
• /
• 2016.11a
• /
• pp.171-173
• /
• 2016

일반적으로 대형 버스 및 트럭 등 같은 경우, 부하가 아주 크다. 또한 내리막길이나 장거리 운행 시에 잦은 제동으로 인하여 마찰을 이용한 기존 방식의 브레이크들은 브레이크 파열 및 페이드 현상 때문에 제동 안전성에 문제가 있다. 이러한 제동 부담을 분담하기 위해 현재 보조브레이크(리타더)가 필수적이며, 엔진 계통의 보조브레이크가 아닌 비접촉식 브레이크 같은 친환경 보조브레이크가 요구되고 있다. 그리고 차량 제동시 발생하는 기계에너지를 전기에너지로 회생하여 에너지효율을 향상시키려는 연구가 현재 활발히 진행되고 있다. 본 논문에서는 와전류를 이용한 전자기형 리타더에서 발생되는 전기에너지를 회수하기 위한 전압 제어 방법을 다룰 것이다. 리타더의 제동에너지를 전기에너지로 회생하기 위해 L-C 공진회로로 구성하였다. 리타더를 자여자 유도발전기(Self-Excited Induction Generator)로 모델링 하였고 이를 토대로 시뮬레이션 및 실험을 진행하였다. 자여자 유도발전기의 구동 조건에 대해서 언급하고 이를 파라미터에 따라 3-D map으로 만들었다. 또 회로 중의 FET 게이트에 전압을 인가하는 제어장치의 구동펄스에 따라 바뀌는 공진회로의 전압을 분석하였으며, 이 전압을 제어하기 위하여 PI 제어기를 이용한 알고리즘을 제안하였다. 이 전압을 3상 AC/DC컨버터를 통과한 후 DC/DC컨버터를 통하여 차량 내부의 배터리에 충전되는데 제어를 위해 3상 AC/DC에서의 전압 리플을 MA(Moving Average) 방식의 필터를 사용하여 DC/DC컨버터의 입력에 맞도록 제어하였다. 이와 같이 전자기형 리타더에서 유도되는 전압을 제어기의 제어 펄스에 따라 제어할 수 있으며 Matlab Simulink를 이용하여 리타더의 모델과 그 제어기의 타당성을 보였다. 또 실제 M-G Set 실험을 통하여 그 연관성을 확인하였다.