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  • Title/Summary/Keyword: Obstacle model

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Rotational Wireless Video Sensor Networks with Obstacle Avoidance Capability for Improving Disaster Area Coverage

  • Bendimerad, Nawel;Kechar, Bouabdellah
    • Journal of Information Processing Systems
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    • v.11 no.4
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    • pp.509-527
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    • 2015
  • Wireless Video Sensor Networks (WVSNs) have become a leading solution in many important applications, such as disaster recovery. By using WVSNs in disaster scenarios, the main goal is achieving a successful immediate response including search, location, and rescue operations. The achievement of such an objective in the presence of obstacles and the risk of sensor damage being caused by disasters is a challenging task. In this paper, we propose a fault tolerance model of WVSN for efficient post-disaster management in order to assist rescue and preparedness operations. To get an overview of the monitored area, we used video sensors with a rotation capability that enables them to switch to the best direction for getting better multimedia coverage of the disaster area, while minimizing the effect of occlusions. By constructing different cover sets based on the field of view redundancy, we can provide a robust fault tolerance to the network. We demonstrate by simulating the benefits of our proposal in terms of reliability and high coverage.

A Study on the Design and Chracteristic Analysis for Noise Cut Transformer (NCT 설계 및 특성 분석에 관한 연구)

  • 이재복;허창수
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.12 no.4
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    • pp.146-154
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    • 1998
  • Broadband noise with frequency components in the range from several kHz up the tens of MHz is a major obstacle factor in normal operation of the AC line to supply the power to electrical and electronic control equipments. Because this kind of noise could damage the device or could be a source of malfunction, many devices such as filter and surge suppressor are used to cut off the noise. But those devices could not disconnected from the power line, so they result in poor common-mode of NCT as well as insulation characteristics as a isolation transformer in addition faraday shielding and proposed analysis model of NCT having tow functions of surge and noise reduction. The simulated and experimental results for the surge suppression characteristics are compared and evaluated for designed protype 1[kVA] NCT.

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Fast Macroblock Mode Selection Algorithm for B Frames in Multiview Video Coding

  • Yu, Mei;He, Ping;Peng, Zongju;Zhang, Yun;Si, Yuehou;Jiang, Gangyi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.5 no.2
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    • pp.408-427
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    • 2011
  • Intensive computational complexity is an obstacle of enabling multiview video coding for real-time applications. In this paper, we present a fast macroblock (MB) mode selection algorithm for B frames which are based on the computational complexity analyses between the MB mode selection and reference frame selection. Three strategies are proposed to reduce the coding complexity jointly. First, the temporal correlation of MB modes between current MB and its temporal corresponding MBs is utilized to reduce computational complexity in determining the optimal MB mode. Secondly, Lagrangian cost of SKIP mode is compared with that of Inter 16×16 modes to early terminate the mode selection process. Thirdly, reference frame correlation among different Inter modes is exploited to reduce the number of reference frames. Experimental results show that the proposed algorithm can promote the encoding speed by 3.71~7.22 times with 0.08dB PSNR degradation and 2.03% bitrate increase on average compared with the joint multiview video model.

A Study on the Establishment of Minimum Safe Altitude and UAS Operating Limitations (최저비행고도와 UAS 운영제한고도 구축에 관한 연구)

  • Kim, Do Hyun;Lee, Dong Jin
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.29 no.2
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    • pp.94-99
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    • 2021
  • UTM is an air traffic management ecosystem under development for autonomously controlled operations of UAS by the FAA, NASA, other federal partner agencies, and industry. They are collaboratively exploring concepts of operation, data exchange requirements, and a supporting framework to enable multiple UAS operations beyond visual line-of-sight at altitudes under AGL 500ft in airspace where air traffic services are not provided. Minimum Safe Altitude is a generic expression, used in various cases to denote an altitude below which it is unsafe to fly owing to presence of terrain or obstacles. The European drone regulation mentions that the UAS is maintained within 120 metres from the closest point of the surface of the earth during flight, except when overflying an obstacle. This study attempted to develop a minimum flight altitude database system. Based on domestic and international rules and regulations on setting the minimum flight altitude it is expected that it can be applied to the operation of aircraft and unmanned aerial system in UTM environments for specific area in Korea.

Research on the construction concept and general framework of Smart Water Resource

  • Tian, Yu;Li, JianGuo;Jiang, Yun-zhong
    • Proceedings of the Korea Water Resources Association Conference
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    • 2015.05a
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    • pp.216-216
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    • 2015
  • Frequent hydro-meteorological events caused by global climate change and human exacerbate activities, make the water resource problem more complicated. The increasing speed urbanization brings a significant impact on the city flood control and security, water supply safety, water ecological security, water environment safety and the water engineering security in China, and puts forward higher requirements to urban water integrated management, undoubtedly which become the biggest obstacle for water ecological civilization construction, thus urgent requiring an advanced methods to enhance the effectiveness of the water integrated management. The other fields of smart ideas point out a development path for water resource development. The construction demand of smart water resource is expounded in the paper, combining the philosophy of modern Internet of things with the application of cloud computing technology. The concept of smart water resource is analyzed, the connotation characteristics of smart water resource is extracted, and the general model of smart water resource is refined. Then, the frame structure of smart water resource is put forward. The connotation and the overall framework of the smart water resource represent a higher level of water resource informationization development and provide a comprehensive scientific and technological support to transform water resource management from an extensive, passive, static, branch and traditional management to a fine, active, dynamic, collaborative and modern management.

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Numerical analysis on thermal runaway by cathode active materials in lithium-ion batteries (리튬이온전지 열폭주에 대해 양극활물질이 미치는 영향에 대한 수치해석적 연구)

  • Gang, Myung-Bo;Kim, Nam-Jin
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.17 no.2
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    • pp.1-10
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    • 2021
  • Lithium-ion batteries with high energy density, long cycle life and other advantages, have been widely used to energy storage systems(ESS). But as ESS fires frequently occur, the safety concern has become the main obstacle that hinders the large-scale applications of lithium-ion batteries. Especially, thermal runaway is the key scientific problem in battery safety research. Therefore, in this study, we performed a numerical analysis on the thermal runaway phenomenon of NCM111, NCM523 and NCM622 batteries using a two-dimensional analysis model. The results show that the two-dimensional simulation results are generally matched with three-dimensional simulation. Also, In the case of NCM111 with a low Ni content in the temperature range used in this study, thermal runaway phenomenon does occurred very slowly, but as the Ni content is increased, the thermal runaway phenomenon occurs rapidly and the thermal stability tends to be decreased. And, in NCM523 and NCM622 batteries, chain reactions occur almost simultaneously, but in the case of NCM111 battery, it is found that after the SEI(Solid Electrolyte Interface) layer decomposition reaction, the cathode-electrolyte reaction is appeared sequentially. After that, the anodic decomposition reaction is increased and leads to the thermal runaway reaction.

Factors Influencing Roadkill Hotspot in the Republic of Korea

  • Kim, Kyungmin;Yi, Yoonjung;Woo, Donggul;Park, Taejin;Song, Euigeun
    • Proceedings of the National Institute of Ecology of the Republic of Korea
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    • v.2 no.4
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    • pp.274-278
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    • 2021
  • Road structures play an important role in collisions involving vehicles and wildlife. Our study aimed to determine the effect of various types of road structures on the risk associated with roadkill. We surveyed 50 previously identified roadkill hotspots, ranked from one to five according to roadkill density. We collected nine types of road structure data on each hotspot road section. Structures with similar characteristics were grouped together, resulting in five categories, namely, median barrier, high edge barrier, low edge barrier, speed, and visibility. We examined the existence of each road structure category at each hotspot rank. The cumulative link model showed that the absence of bottom blocked median barrier increased the roadkill hotspot rank. Our study concluded that a visual obstacle in the middle of roads by the median barrier decreases wildlife road crossing attempts and roadkill risk. We suggest that future roadkill mitigation plans should be established considering these characteristics.

Analyzing Public Preference for Community-Based Floating Photovoltaic Projects: A Discrete Choice Experiment Approach (주민참여형 수상태양광 발전사업에 대한 국민 선호도 분석: 선택실험법을 이용하여)

  • Hye Lee, Lee;JongRoul, Woo
    • Current Photovoltaic Research
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    • v.10 no.4
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    • pp.121-132
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    • 2022
  • The need for floating photovoltaic is being emphasized to expand renewable energy but low residents' acceptance is a major obstacle to the deployment of floating photovoltaic. Using the discrete choice experiment, this study analyzed the preferences for community-based floating photovoltaic projects and proposed a method to increase the residents' acceptance of floating photovoltaic projects. The estimates of the marginal willingness to accept (MWTA) of the distance, the coverage ratio, the landscape, the project owner (public institution), and the project owner (large company) are -0.69%p/km, 0.13%p/%p, -0.57%p, -2.95%p, -1.73%p, respectively. According to the result of simulation analysis, the residents' acceptance is significantly higher when the project is operated by a public institution, with a choice probability of 58%, than when the project is operated by a private company, with a choice probability of 29%, 12% for a large and small company, respectively. In addition, as a result of the analysis of the expected returns, the results show that the closer the distance from the residence to the power plant, the higher the expected return.

Research and Calculate 29/34-Seat Passenger Cars to Ensure Safety for Occupants in the Event of a Collision According to ECE R94 Standards

  • Vu Hoang, Phuong;Nguyen Cong, Thanh;Nguyen Quoc, Tuan;Ta Hong Thanh, Tu
    • International Journal of Internet, Broadcasting and Communication
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    • v.15 no.1
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    • pp.140-144
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    • 2023
  • In recent years, there are so many serious crashes involving coaches, especially the frontal collision occupies 40% of the front of the vehicle, Frontal collisions account for 100% of the front of the vehicle affecting the driver and side-impact collisions that injure the person in the vehicle. Therefore, the research into improving and optimizing the structure is necessary for risk of injury for passengers in frontal accidents. In this paper, we have designed a Shock absorber that can absorb collision energy. Research using HYPERMESH software. to build the finite element model and calculate the meshing to suit the mesh size of 5mm. apply LS-DYNA software to calculate structural strength. In the study, for a vehicle to collide with a hard obstacle occupying 100% of the head of the vehicle. Then, the experimental design method, Minitab is used for find the structural parameters in the design. Improvement results showed that the acceleration of the impact on passengers and the driver is decreased by 55,17%. The mass of texture improvements is reduced by 11%, according to the requirements of European Standards ECE R94.

Research of 3D image processing of VR technology in medicine based on DNN

  • ZhaoZhe, Gong;XiaoDong, Li;XiaoYing, Shi;Geng, Liu;Bin, Chen
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.5
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    • pp.1584-1596
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    • 2022
  • According to a survey published in an authoritative journal in January 2020, the globalincidence rate of mental illness is 8.3% for men and 10.6% for women, which indicates thatmental illness has become a globally recognized obstacle. Therefore, specific psychotherapy including mental illness will become an important research topic. It is very effective forpatients with special mental diseases, such as mental illness, to reduce their mental reaction byexposure therapy; the system uses the virtual reality system of medical images processed by learningalgorithm to reproduce the effect of virtual reality exposure method of the high scene of transparent ladder. Compared with the old invasive exposure scene, the results show that theimprovement of both conditions has obvious effect, and the effect of human treatment underthe two conditions is not good. There are obvious differences, which show that virtual reality model will gradually replace the on-the-spot feeling. Finally, with more and more researchers have put forward a variety of other virtual reality image processing models, the research of image processing has gradually become more and more interested.