• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.871-876
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• 2022

In the construction industry, fatal accidents related to scaffolds frequently occur. To prevent such accidents, scaffolds should be carefully monitored for their safety status. However, manual observation of scaffolds is time-consuming and labor-intensive. This paper proposes a method that automatically analyzes the installation status of scaffold joints based on images acquired from a Unmanned Aerial Vehicle (UAV). Using a deep learning-based object detection algorithm (YOLOv5), scaffold joints and joint components are detected. Based on the detection result, a two-stage rule-based classifier is used to analyze the joint installation status. Experimental results show that joints can be classified as safe or unsafe with 98.2 % and 85.7 % F1-scores, respectively. These results indicate that the proposed method can effectively analyze the joint installation status in UAV-acquired scaffold images.

• International Journal of Advanced Culture Technology
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• 제8권1호
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• pp.135-140
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• 2020

The main battlefield of 'made in China 2025' proposed by the Chinese government is the deep integration of industrialization and informatization, among which intelligent manufacturing and new energy vehicles are the key links. New energy vehicle refers to the use of unconventional automotive fuel as a power source (or use conventional automotive fuel, the use of new vehicle-mounted power plant), integrated vehicle power control and driving aspects of advanced technology, the formation of advanced technical principles, with new technology and the structure of the vehicle. BYD's success in the battery, I T and automobile industries has attracted the attention of the industry, making it a shining new star in the Chinese business community. BYD 's innovation, diversification and corporate culture construction have certain enlightenment to the development of China's small and medium-sized enterprises. Therefore, by looking at the Chinese network literature, about BYD's research mainly focused on the development strategy, corporate finance, corporate performance, and corporate marketing, etc. This paper will take BYD as the research object and focus on corporate culture. Through literature analysis and qualitative analysis, it will summarize and further analyze the unique corporate culture of BYD, its important role, and provide relevant theoretical references for the construction and development of corporate culture in other industries.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.975-979
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• 2008

Since tram has the advantages to reduce construction cost of infrastructure, to improve accessibility of passengers, and to offer visual pleasures, nowadays, it is one of light rails attracting public attention. Tram can be classified into two groups, one is a conventional steel-wheeled type, and the other is a rubber-tired type (bi-modal tram). The bi-modal tram propelled by the serial CNG hybrid propulsion unit has been developing since 2003 in Korea, which can realize both scheduled operation of railway and route flexibility of bus. Because the bimodal will be operated on both railway mode and bus mode, however, specific criteria and regulations for its design, certification, construction, operation and maintenance have not been determined definitely yet. In consideration of mobility enhancement for the old and the handicapped, motor vehicle safety standard and urban transit (railway vehicle) safety standard, several design specifications were proposed for car body and interiors of the bimodal tram vehicle. The design specifications proposed in this paper can be expected to promote passengers' comfort and safety, operation efficiency of the bimodal tram.

• 드라이브 ㆍ 컨트롤
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• 제16권1호
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• pp.14-21
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• 2019

Axial piston pump is a significant part in wheeled armored vehicle, for generating hydraulic power of vehicle power system. The Axial Piston Pump is a high-performer, core functional item that is developed and applied to most of the military models in the development of military weapon systems. However, in the case of military equipment, there are conditions of limited size and weight required depending on the operating conditions and the operating environment. Under these conditions, it is required that the performance and the environmental resistance are verified to exert the required output. A unique technology is needed for the development of such equipment both in the present and in the future. Therefore, in this study, mathematical modeling of an axial piston pump is presented as a basic data for securing proprietary technology. In addition, a simulation model is designed and compared with the models of six kinds of pistons through simulation. It was established that when the number of pistons of the axial piston pump, which is the development objective, is seven, the model is suitable for the wheeled armored vehicle.

• Ecology and Resilient Infrastructure
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• 제6권4호
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• pp.277-286
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• 2019

건설산업은 미세먼지를 많이 발생시키는 산업 중 하나인 것으로 알려져 있다. 따라서 건설산업에서의 미세먼지 발생량을 줄이는 것이, 전체 미세먼지 관리에 매우 중요하다. 이러한 점에 착안하여, 본 연구에서는 자율이동체, IoT, 드라이 포그 시스템 등 첨단기술을 활용한 미세먼지 모니터링 및 제거기술을 제안하고, 시스템의 구성과 작동순서를 제시하였으며, 시스템 도입의 효과를 정성적, 정량적 측면에서 분석하였다. 제안된 개념과 구성 그리고 작동순서는 실제 시스템 개발 및 현장적용을 통해 그 실효성을 검증할 예정이다. 또한 비용편익분석 등을 통해 구체적인 경제성도 검증할 계획이다.

• 한국도로학회논문집
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• 제13권4호
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• pp.167-175
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• 2011

효율적인 도로의 설계와 관리를 위해서는 도로건설의 경제성 분석이 중요하며 이를 위해서는 도로 상태별 차량별 유류소모량의 평가가 필요하다. 도로에서는 초기 건설비용, 유지보수비용, 차량운행비용, 지정체비용 등이 발생되는데, 도로의 경제성 분석을 위해서는 초기 건설비용, 유지보수비용 등과 같은 관리자비용과 차량운행비용, 지정체비용 등과 같은 이용자비용을 모두 포함한 사회적 비용이 고려되어야 한다. 이 중 차량운행비용은 교통량에 따라 그 비용이 변화되므로 차량운행비용 항목의 큰 부분을 차지하는 유류소모량 또한 교통량에 따라 변화하게 된다. 그런데 유류소모량은 차량의 주행속도 및 도로포장의 상태, 특히 평탄성에 따라 크게 변화되므로 도로의 경제성 분석을 위한 차량운행비용의 산정을 위해서는 주행차량에 대해 도로 상태에 따른 유류소모량을 평가하여 경제성 분석에 반영해야 할 필요가 있으나 아직 이를 고려하지 못하고 있는 상황이다. 본 연구에서는 국내에서 운행되는 승용차에 대해서 도로 상태별 유류소모량 추정모델을 개발하였다. 우선 우리나라의 교통시설 투자평가 및 도로건설의 예비타당성 조사에서 차량운행비용 산정을 위해 사용되고 있는 주행속도와 유류소모량의 관계식을 고찰하고, 승용차를 대상으로 도로포장의 평탄성에 따른 유류소모량 변화의 관계를 실제 도로에서 실측하여 평탄성과 유류소모량 변화의 관계를 분석하였다. 실험 결과, 평탄성에 따른 유류소모량의 변화는 평탄성이 1m/km 증가하였을 경우 100km 주행시 약 $80m{\ell}$ 정도의 비율로 유류소모량이 증가하는 것으로 확인되었다. 따라서 도로의 설계 및 유지관리에 있어서 보다 정확한 경제성 분석을 수행하기 위해서는 도로포장의 평탄성에 따른 유류소모량 변화를 고려해야 할 필요가 있다.

• 수산해양기술연구
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• 제33권4호
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• pp.290-297
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• 1997

Underwater robotic vehicles(URVs) are used for various work assignments such as pipe-lining, inspection, data collection, drill support, hydrography mapping, construction, maintenance and repairing of undersea equipment, etc. As the use of such vehicles increases the development of vehicles having greater autonomy becomes highly desirable. The vehicle control system is one of the most critic vehicle subsystems to increase autonomy of the vehicle. The vehicle dynamics is nonlinear and time-varying. Hydrodynamic coefficients are often difficult to accurately estimate. It was also observed by experiments that the effect of electrically powered thruster dynamics on the vehicle become significant at low speed or stationkeeping. The conventional linear controller with fixed gains based on the simplified vehicle dynamics, such as PID, may not be able to handle these properties and result in poor performance. Therefore, it is desirable to have a control system with the capability of learning and adapting to the changes in the vehicle dynamics and operating parameters and providing desired performance. This paper presents an adaptive and learning control system which estimates a new set of parameters defined as combinations of unknown bounded constants of system parameter matrices, rather than system parameters. The control system is described with the proof of stability and the effect of unmodeled thruster dynamics on a single thruster vehicle system is also investigated.

• 한국강구조학회 논문집
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• 제14권6호
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• pp.711-720
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• 2002

본 연구에서는 곡선교에서 주행차량에 의한 동적 응답을 보다 정밀하게 구현할 수 있는 3차원 해석 모형을 개발하였다. 원심력에 의한 차량의 롤링운동에 따른 차량의 쏠림현상을 구현하여 곡선교의 대표적인 응답특성인 편경사와 곡률반경에 따른 동적응답과 받침의 변화에 따른 동적 응답 특성을 규명하였으며, 2가지 지점조건에 대하여 주행차량에 의한 곡선교의 동적 특성을 비교 분석하였다. 또한 이와 함께 곡선교에서 어떤 파라미터가 하중 분배에 가장 효율적인가를 비교 분석하였다. 동적해석결과 받침이 외측에 배치된 경우가 중앙에 배치된 경우보다 더 유리하게 분석되었으며, 여러 가지 조건에 따라 하중분배 특성이 다르게 나타남을 알 수 있었다.

• 산업경영시스템학회지
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• 제42권4호
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• pp.23-30
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• 2019

Automobiles are largely divided into passenger cars with less than five passengers and commercial vehicles such as construction machines, trucks, mixers, special lorries, and large buses. Automobile maintenance companies are also divided into passenger cars and commercial vehicles. Because commercial vehicles are the livelihood vehicles of individual carriers engaged in cargo transportation, passenger transportation, and construction, fast and accurate maintenance is important. Access to the expressway is also important because the car is large and uses highways. In addition, the time required for troubleshooting is long, so sufficient space must be secured for parking the vehicle, and ease of entry and exit of the vehicle in the maintenance shop should be fully considered. For this reason, commercial vehicle maintenance companies have higher initial investment costs than car maintenance companies, and it is difficult to supply and maintain maintenance personnel. Therefore, it is necessary to carefully examine and analyze various related factors for successful commercial vehicle maintenance company selection. However, most existing commercial vehicle maintenance companies often choose their location based on the empirical judgment of the founder, the customs and the case, without a clear analysis. In this study, we show how to derive the location selection factors to be considered when establishing professional maintenance company for commercial vehicles and to select the optimal location by using AHP (Analytic Hierarchy Process) method.

• 한국강구조학회 논문집
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• 제9권3호통권32호
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• pp.309-321
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• 1997

차량이 교량을 통과할 때 교량에 발생하는 충격계수는 교량의 설계시 매우 중요한 인자이다. 본 연구에서는 2연속 강판형교의 지간 중앙점에 발생하는 충격계수에 관한 실험 및 해석적 연구를 수행하였다. 교량의 수치해석시 교량과 차량은 3차원으로 모델링하였으며. 교량의 노면조도는 Intelligent Total Station으로 직접 측정하여 사용하였다. 이때 교량의 주형은 보요소, 콘크리트 바닥판은 쉘요소를 사용하고 주형과 콘크리트 바닥판 사이는 Rigid Link를 사용하여 연결시켰다. 교량과 차량 사이의 상호작용을 고려하여 차량의 운동방정식을 유도하였으며, 차량의 여러 가지 주행속도에 따른 교량의 지간 중앙점에서의 충격계수를 구하여 우리나라 및 외국의 시방서 규정과 비교 검토하였다.