• Title/Summary/Keyword: traffic condition

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A Fundamental Study on Analysis of Electromotive Force and Updating of Vibration Power Generating Model on Subway Through The Bayesian Regression and Correlation Analysis (베이지안 회귀 및 상관분석을 통한 지하철 진동발전 모델의 수정과 기전력 분석)

  • Jo, Byung-Wan;Kim, Young-Seok;Kim, Yun-Sung;Kim, Yun-Gi
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.2
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    • pp.139-146
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    • 2013
  • This study is to update of vibration power generating model and to analyze electromotive force on subway. Analysis of electromotive force using power generation depending on classification of locations which are ballast bed and concrete bed. As the section between Seocho and Bangbae in the line 2 subway was changed from ballast bed to concrete bed, it could be analyzed at same condition, train, section. Induced electromotive force equation by Faraday's law was updated using Bayesian regression and correlation analysis with calculate value and experiment value. Using the updated model, it could get 40mV per one power generation in ballast bed, and it also could get 4mV per one power generation in concrete bed. If the updated model apply to subway or any train, it will be more effective to get electric power. In addition to that, it will be good to reduce greenhouse gas and to build a green traffic network.

Test-bed Development for Long-term Monitoring of Small Bridge Asset Management (소규모 교량 자산관리를 위한 계측 테스트베드 구축)

  • Park, Jae-Woo;Chae, Myung-Jin;Lee, Giu;Cho, Moon-Young
    • Korean Journal of Construction Engineering and Management
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    • v.13 no.6
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    • pp.13-23
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    • 2012
  • While Category 1 and Category 2 bridges are intensively inspected and carefully managed, many small bridges that are not in the Category 1 and 2 are often forgotten until they decay in serious condition. Since many of these small bridges located in the populated city, failure of them would cause huge negative impact on the community. This paper focuses on the small size concrete bridges for timely repair and rehabilitation work for the effective operation and management. Test bed is developed to define the key parameters to forecast the long term performance of the bridges, mostly concrete box bridges. Key parameters suggested in this paper are cumulative fatigue due to repetitive heavy traffic loads and the acid attacks for concrete material deterioration. The cumulative fatigue is measured by the use of the mileage concept. For the long term data collection and inspection, stable and easy to use data collection system is installed as a test bed. The contribution of this research work is on the development of the test bed to define the key parameters of bridge deterioration.

A Comparison Study of Model Reduction Method with Direct Impact Analysis of Truck-column Collision (모델축소법을 이용한 교각-차량 충돌변위 예측 및 직접충돌해석법과의 비교연구)

  • Lee, Jaeha;Kim, Kyeongjin;Jeong, Yoseok;Kim, Wooseok
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.28 no.6
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    • pp.675-682
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    • 2015
  • Current design codes such as AASHTO LRFD or Korean Highway Bridge Design Code recommend of using static force for designing bridge column against vehicle collisions. However, there was an accident that the bridge was collapsed shortly after vehicle impact on bridge pier in Nebraska(near Big Spring, 2003). It was found that the second largest cause of bridge collapse is collision after hydraulic causes. It can be thought that the possibility of truck-bridge collision are getting increasing as the size of truck increases and traffic condition are becoming improved. However, dynamic behavior under the impact loading seldom considered in bridge design procedure due to computational cost and time. In this study, in order to reduce the computational cost for dynamic impact analysis, model reduction method was developed. Obtained results of residual displacement were compared with the results of direct impact simulations.

The Improvement Index of Smart Public Services to Advance Information Accessibility for the Elderly (고령자 정보접근성 향상을 위한 스마트 공공서비스 지표)

  • Kim, Mi-Yun;Byun, Sung-Jun
    • Journal of Digital Convergence
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    • v.16 no.5
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    • pp.43-53
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    • 2018
  • Recently, public service for the improvement of quality of life and life support such as safety, aging, disaster, welfare, housing, economy, urban environment, traffic etc are actively developed based on open public data, and the spread of the network and the necessity of everyday life, smartphones are playing a role in providing public services. Currently, the development of science is changing the life expectancy of human beings and changing into social structure in which aged people become bigger due to various social conditions and low fertility and aging problems. However, the elderly who do not have easy access to information are very uncomfortable in dealing with mobile devices with very low accessibility and utilization of public services provided by mobile phones. Therefore, this study recategorizes the condition of the elderly presented in the previous study and identifies the problem through case analysis provided for the elderly. Also, we summarize the hierarchy of the core items of the existing interface design and derive it as an improvement index of the public service design for the improvement of the information accessibility of the elderly, and propose a design method to improve the utilization of the public service provided through the mobile device.

QoS improving method of Smart Grid Application using WMN based IEEE 802.11s (IEEE 802.11s기반 WMN을 사용한 Smart Grid Application의 QoS 성능향상 방안 연구)

  • Im, Eun Hye;Jung, Whoi Jin;Kim, Young Hyun;Kim, Byung Chul;Lee, Jae Yong
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.11-23
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    • 2014
  • Wireless Mesh Network(WMN) has drawn much attention due to easy deployment and good scalability. Recently, major power utilities have been focusing on R&D to apply WMN technology in Smart Grid Network. Smart Grid is an intelligent electrical power network that can maximize energy efficiency through bidirectional communication between utility providers and customers with ICT(Information Communication Technology). It is necessary to guarantee QoS of some important data in Smart Grid system such as real-time data delivery. In this paper, we suggest QoS enhancement method for WMN based Smart Grid system using IEEE 802.11s. We analyze Smart Grid Application characteristics and apply IEEE 802.11s WMN scheme for Smart Grid in domestic power communication system. Performance evaluation is progressed using NS-2 simulator implementing IEEE 802.11s. The simulation results show that the QoS enhancement scheme can guarantee stable bandwidth irrespective of traffic condition due to IEEE 802.11s reservation mechanism.

The study of Estimation model for the short-term travel time prediction (단기 통행시간예측 모형 개발에 관한 연구)

  • LEE Seung-jae;KIM Beom-il;Kwon Hyug
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.3 no.1 s.4
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    • pp.31-44
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    • 2004
  • The study of Estimation model for the short-term travel time prediction. There is a different solution which has predicted the link travel time to solve this problem. By using this solution, the link travel time is predicted based on link conditions from time to time. The predicated link travel time is used to search the shortest path. Before providing a dynamic shortest path finding, the prediction model should be verified. To verify the prediction model, three models such as Kalman filtering, Stochastic Process, ARIMA. The ARIMA model should adjust optimal parameters according to the traffic conditions. It requires a frequent adjustment process of finding optimal parameters. As a result of these characteristics, It is difficult to use the ARIMA model as a prediction. Kalman Filtering model has a distinguished prediction capability. It is due to the modification of travel time predictive errors in the gaining matrix. As a result of these characteristics, the Kalman Filtering model is likely to have a non-accumulative errors in prediction. Stochastic Process model uses the historical patterns of travel time conditions on links. It if favorably comparable with the other models in the sense of the recurrent travel time condition prediction. As a result, for the travel time estimation, Kalman filtering model is the better estimation model for the short-term estimation, stochastic process is the better for the long-term estimation.

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Problems on Pesticide Safe-Use and Their Counter-Measures (농약안전사용상의 문제점과 그 대책)

  • Han Ki-Hak
    • Korean journal of applied entomology
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    • v.22 no.2 s.55
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    • pp.138-146
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    • 1983
  • With the increase of pesticide consumption, not only pesticide handling population would grow greater but also the chances to be exposed to the pesticides would be also increased. Thus, safe use and handling of the pesticides are becoming more important and serious in these days. The pesticides are well known to most pepole, however there are very limited number of persons who have correct understanding of chamicals. Intoxication cases caused by pesticides have been reported very rarely through the mess media, even they were lack of scientific evidences. In this paper, problems related to pesticide manufacture, transportation, storage, sprays, and residues and their countermeasures were discussed in connection with public health and enviromental aspects. Acute intoxication cases by pesticide handling might be caused accidently either through manufacture, marketing, transportation, or spraying. Safety aspects of workers in manufacturing plants include not only exposure to toxic chemicals, but also posibilities of of explosion and brought about by pesticides and their diluents. The problems of water pollution by waste chemicals from the manufacturing factories were discussed. Packing and loading methods of pesticides for transportation are considered in safety scheme and discussions are given in association with traffic accidents. With regard to warehouse, the pesticide storage, location structure, keepers, and standing materials for emergency are concerned with safety aspects. Concerning the spraying of chemicals, there are some problems to be discussed about clothes, spray equipment, wind direction, spray period, and spray workers condition. After the spray, treatment of used containers, remainder of Pesticides, and spray tools are also discussed. For the dissolutions of problems on public health and environmental danger arising from pesticide residues, there are two legal sanctions; 'Pesticide Tolerances' and 'Pesticide Safe Use Standards'. These regulations are legally effective, however, some problems still remain in practices to implement the acts properly, because these provisions are followed by the far mers mostly. With these regards, most problems are concerned with various sectors and persons, affecting public health and environment from the producers to the end users and consumers. As a whole persons concerned with pesticides, every possible effort has to be assembled to protect hazards from the chemicals. For the foremost place, special training and education are required for managing groups; such as factory managers and agricultural extension workers who are responsible for training the factory workers and farmers. The education is the only way to solve the hazard problems caused by the pesticides.

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New Gain Function Based on Attenuation Characteristics of Ballast Track for GPR Analysis (GPR 분석을 위한 자갈궤도 자갈의 감쇄특성을 이용한 이득함수 개발)

  • Shin, Jihoon;Choi, Yeongtae;Jang, SeungYup
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.4
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    • pp.13-21
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    • 2017
  • Ballasted track has been used as track system for more than 100 years. Ballasted track has advantages of low construction cost, flexible maintenance, low noise and vibration, and so on. However, ballasted track leads to continuous settlement which causes maintenance. Recently, increase in speed, traffic volume, and weight of train requires more frequent maintenance. Fouling, well-known phenomenon of accumulation of fine materials due to intrusion of subgrade and breakage of ballast materials, expedites the settlement (i.e., irregular settlement) of track. Ground Penetrating Radar (GPR) can be one of non-destructive tools that can evaluate fouling level of ballast. In this paper, a gain function based on the attenuation characteristics of ballast material is suggested in conjunction with Hilbert transform. Lab box tests and full-scale tests indicate that the suggested method reasonably classifies clean, fouled layers, and subgrade. However, additional study to eliminate effect of sleeper and to include the scattering features of the electromagnetic wave in ballast voids should be required in order to enhance the accuracy.

Characteristic of Local Behavior in Orthotropic Steel Deck Bridge with Open Ribs according to Running Vehicle (주행차량에 따른 개단면 강바닥판 교량의 국부거동 특성)

  • Lee, Sung-Jin;Kyung, Kab-Soo;Park, Jin-Eun;Lee, Hee-Hyun
    • Journal of Korean Society of Steel Construction
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    • v.24 no.1
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    • pp.101-108
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    • 2012
  • The orthotropic steel deck bridge made by using relatively thin steel plate, and structural members such as transverse and longitudinal ribs, cross beam, etc. in the bridge are fabricated with complex shape by welding. Therefore, the possibility occurring deformation and defects by welding is very high, and stress states in the welded connection parts are very complex. Also, the fatigue cracks in orthotropic steel deck bridge are happening fromthe welded connection parts of secondary member than main member. However, stress evaluation for main members is mainly carried out in the design process of the bridge, detailed stress evaluation and characteristic analysis is not almost reviewed in the structural details which fatigue crack occurred. For the orthotropic steel deck bridge with open ribs which has been serviced for 29 years, in this study, the cause of fatigue crack is investigated and the fatigue safety of the bridge is examined based on fieldmeasurement by the loading test and real traffic condition. Also, structural analyses using gridmodel and detailed analysis model were carried out for the welded connection parts of longitudinal rib and diaphramthat fatigue crack occurred. Additionally, the behavior characteristics due to running vehicles were investigated by using influence area analysis for these structural details, and the occurrence causes of fatigue crack in the target bridge were clarified.

Detailed Analysis of Vertical Connector in Modular Roadway Slab Under Temperature and Lifting Loading (온도하중과 인양하중에 영향을 받는 모듈러 도로 슬래브 수직연결부의 상세해석)

  • Kim, WooSeok;Nam, Jeonghee;Min, Geunhyeong;Kim, Kyeongjin;Lee, Jaeha
    • Journal of the Korea Concrete Institute
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    • v.28 no.5
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    • pp.509-517
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    • 2016
  • In terms of bridge construction, the concrete deck slab is weak members compared to beam members of the bridge supports. Deck slabs must be sound to support and distribute vehicle loads. If slabs are not enough to support the loads, it should be replaced. Bridge deck replacement has been an important industry over the world since the construction is simplified to shorten construction time and to save construction costs. Slab module provides a quickly, easily and reliably construction method in order to avoid high cost and minimum traffic disruption. in addition, slab module shows high reliability since they are factory products. However, slab module should be considered in the performance under various loads. In this study, structural analysis is performed to evaluate the performance of slab module under vehicle loads and temperature loads. Spiral rebar is also utilized around the vertical joints to improve the structural integrity under the lifting loads. In order to confirm the weak area of slab module for the lift condition, numerical analysis has been performed.