• 제목/요약/키워드: Heavy Equipment

검색결과 500건 처리시간 0.021초

Vertical response spectra for an impact on ground surface

  • Constantopoulos, Ioannis V.;Van Wessem, Yukiko;Verbrugge, Jean-Claude
    • Earthquakes and Structures
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    • 제3권3_4호
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    • pp.435-455
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    • 2012
  • An impact on the ground surface may represent several phenomena, such as a crash of an airplane or an explosion or the passage of a train. In order to analyze and design structures and equipment to resist such a type of shocks, the response spectra for an impact on the ground must be given. We investigated the half-space motions due to impact using the finite element method. We performed extensive parametric analyses to define a suitable finite element model and arrive at displacement time histories and response spectra at varying distances from the impact point. The principal scope of our study has been to derive response spectra which: (a) provide insight and illustrate in detail the half-space response to an impact load, (b) can be readily used for the analysis of structures resting on a ground subjected to an impact and (c) are a new family of results for the impact problem and can serve as reference for future research.

Development of Simulation Model for PEMFC Hybrid Excavator (연료전지 시스템을 적용한 하이브리드 굴삭기 해석 모델 개발)

  • Lee, Se Young
    • Journal of Drive and Control
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    • 제16권3호
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    • pp.16-22
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    • 2019
  • Due to the rise in energy consumption and natural resource prices, the demand to improve energy efficiency in the construction machine has been highlighted. Even though many researchers have contributed to the development of the technology, CO2 gas emissions of heavy machinery remains high. One of the most significant problems of the novel excavator with internal combustion engines is the emission of harmful gas. To reduce emissions in the construction machine, it is necessary to replace the internal combustion engines with the alternative one. To overcome those problems, this paper focuses on the adoption of PEMFC hybrid engine for the excavator system. An internal combustion engine is replaced by new structures with fuel cell, battery and ultra capacitor. The proposed system has been designed and modeled using Simcenter Amesim software and compared with the conventional one through simulation results.

Numerical simulation of non-isothermal flow in oil reservoirs using a two-equation model

  • dos Santos Heringer, Juan Diego;de Souza Debossam, Joao Gabriel;de Souza, Grazione;Souto, Helio Pedro Amaral
    • Coupled systems mechanics
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    • 제8권2호
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    • pp.147-168
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    • 2019
  • This work aims to simulate three-dimensional heavy oil flow in a reservoir with heater-wells. Mass, momentum and energy balances, as well as correlations for rock and fluid properties, are used to obtain non-linear partial differential equations for the fluid pressure and temperature, and for the rock temperature. Heat transfer is simulated using a two-equation model that is more appropriate when fluid and rock have very different thermal properties, and we also perform comparisons between one- and two-equation models. The governing equations are discretized using the Finite Volume Method. For the numerical solution, we apply a linearization and an operator splitting. As a consequence, three algebraic subsystems of linearized equations are solved using the Conjugate Gradient Method. The results obtained show the suitability of the numerical method and the technical feasibility of heating the reservoir with static equipment.

Life-Time Prediction of HNBR Diaphragm in Oil Reservoir (유압구동장치 동력원용 고무 다이아프램 저유기의 수명 예측 연구)

  • Kim, Sol A
    • Journal of Drive and Control
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    • 제18권2호
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    • pp.32-37
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    • 2021
  • The piston reservoir is mainly used in hydraulic blow-down system for aerospace engineering. The reservoir is heavy due to both hydraulic cylinder and piston in pressurization. The positive expulsion tank with rubber diaphragm has been mostly applied propellant and fuel tank at low pressure to satellites. To reduce weight, the reservoir that can be used at high pressure with rubber diaphragm was developed. In this research, the prediction of life-time for the rubber diaphragm was implemented through an accelerated life test, as a part of development of new reservoir. Also, the diaphragm was stored in an temperature chamber at the same condition as and operation with hydraulic oil. As a result, the life-time for a rubber diaphragm was successfully evaluated via Arrhenius law and Time-Temperature Superposition based on failure times over temperatures in the accelerated test.

A Suggestion for Worker Feature Extraction and Multiple-Object Tracking Method in Apartment Construction Sites (아파트 건설 현장 작업자 특징 추출 및 다중 객체 추적 방법 제안)

  • Kang, Kyung-Su;Cho, Young-Woon;Ryu, Han-Guk
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 한국건축시공학회 2021년도 봄 학술논문 발표대회
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    • pp.40-41
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    • 2021
  • The construction industry has the highest occupational accidents/injuries among all industries. Korean government installed surveillance camera systems at construction sites to reduce occupational accident rates. Construction safety managers are monitoring potential hazards at the sites through surveillance system; however, the human capability of monitoring surveillance system with their own eyes has critical issues. Therefore, this study proposed to build a deep learning-based safety monitoring system that can obtain information on the recognition, location, identification of workers and heavy equipment in the construction sites by applying multiple-object tracking with instance segmentation. To evaluate the system's performance, we utilized the MS COCO and MOT challenge metrics. These results present that it is optimal for efficiently automating monitoring surveillance system task at construction sites.

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Analysis of Real Ship Operation Data using a Smart Ship Platform (스마트선박 플랫폼을 활용한 실운항 데이터 분석 연구)

  • Kang, Jin-Hui;Lee, Hyun-Ho;Lee, Won-Ju;Lee, In-Ho;Kim, Jae-Woo;Park, Cheong-Hee
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제25권6호
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    • pp.649-657
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    • 2019
  • An essential part of the development of an autonomous ship is supporting technology that can effectively check and diagnose the operational status of the ship form the shore control center on land. This development has recently occurred in the shipbuilding and shipping industries. In this paper, we present a smart ship solution that operates, as a single system, a data collection platform that gathers ship operation data and a service platform that provides various services. When this smart ship solution was applied to an operating ship, it was determined that a variety of high-quality data could be collected compared to existing ship data collection systems. In addition, it was shown that of the operation data collected, analysis of parameters related to the main engine can be used to determine the overall state by deriving valid results and visualizing patterns. In conclusion, it was suggested that a ship's operation status could be checked more effectively and a comprehensive evaluation could be possible at the shore control center if the results of this study were extended to various ship equipment and analyzed together with the operational environment data.

Regional snows scenario for the support systems Analysis (지역별 제설 시나리오 응원체계 구축연구)

  • Kim, Heejae;Oak, Youngsuk;Kim, Geunyoung
    • Journal of the Society of Disaster Information
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    • 제13권2호
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    • pp.163-172
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    • 2017
  • Because of abnormal weather, a heavy snow on the Northern latitudes occurs frequently. This has resulted in significant damage and recovery costs. In korea, it has been declared a special disaster area due to heavy snowfall in Gangneung and Pohang 2004, 2005 and 2011, so there was a revision of action instruction for the road snow removal. Although, in our current system, snow removing methodology, regional equipment holdings, and snow responsible interval, respectively, has been classified by the National Highway, near cities and provinces support system not yet prepared. Only, if snow removing is not possible within the region itself, which contained the contents of "support and assistance to military or nearby offices requests". In this thesis, we studied the disaster scenario development according to heavy snow and the response and support system to the features of each regional. For the scenario deduction, we preferentially collected day snowfall and disaster yearbook data to regionals, classified similar pattern and plotted GIS snow map. We also classified heavy snow disaster by region and type and we deduced five-step scenario. The five-step scenario is nationwide(1st-stage), the National Capital region(2nd-stage), the Chungcheong Provinces(3rd-stage), the Kangwon province(4th-stage) and the Ch?l a provinces(5th-stage). Therefore we build near provinces support system according to five-step scenario.

A Comparative Analysis of the Level of Occupational Health : Before and After the Subsidiary Program on Health Care Management of Small Scale Industries (영세사업장 보건관리 지원사업 실시 전후의 산업보건수준 비교 분석)

  • Jung, Hye Sun
    • Korean Journal of Occupational Health Nursing
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    • 제4권호
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    • pp.58-83
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    • 1995
  • The small scale industries which have less than 30 employees occupy 86.5% of total number of industries in Korea. And though they have higher accident rate and lower environmental condition than big industries, it has been not mandatory to appointing health care manager at factory. So, from 1993, government subsidizes to the health care management of small industries. The purpose of this study is to identify the real feature of health care status in small industries, and to evaluate the level of health care management, before and after the subsidiary program. 65 small plating industries which have been managed by the same health care management support institution in 1993 were selected for study. Of the 65 industries, 3 which have not taken both environmental evaluation and health screening in 1994, and 9 which have closed were excluded from study sample. And the remaining 53 were analyzed by using the results of environmental evaluation and health screening, reported to the Ministry of Labor, before and after the subsidiary program, the analysis was done by the comparison of the two year paired data of the same industry. Over-permissible-limit rate, health screening implementation rate, above grade C rate were calculated and compared. The status of health care management ; 1. Of the sample industries, 96.9% provide protective equipment and 80.0% set up ventilating system. Protective gloves (89.2%) and protective clothing (80.0%) are widely provided, but ear plugs (4.6%) are rarely provided. 21.5% of the protective equipment are well put on, and 40.4% of the ventilating systems function well. 2. In 1993, 35 industries, 53.8% of the sample, checked working environment twice. Over-permissible-limit rates of heavy metal (12.2%), suspended particle (11.1%), noise (5.5%) were high. To put on protective equipment and to set up local ventilating system were pointed out by the examiners. 3. General health screening was done at 63.1% of the sample industries and 35.3% of total workers were examined. Specific health screening was done at 93.8% of the sample industries and 75.4% of workers were examined. 15.5% of workers was provided to be above grade C and to have digestive system disease (43.3%), circulatory disease (18.9%), and hematopoietic disease (14.2%), etc. 4. In 1993, the subsidiary program of health care management was provided in forms of health education, health counseling, and rounding check of working field. And 61.5%, 83.0%, 55.4% of sample industries respectively received it. The average visit per industry was 1.8. Comparisons of the level of occupational health before and after the subsidiary program ; 1. Over-permissible-limit rates of hazardous factors of 1993 and that of 1994 were compared. The rates of suspended particle, noise, organic solvent of 1994 (37.5%, 13.4%, 24.2% respectively) were higher than that of 1993 (25.0%, 6.0%, 6.3% respectively). In the case of acid, there was no difference between the rate of 1993 and that of 1994. Only the rate of heavy metal decreased from 12.9% in 1993 to 3.0% in 1994. 2. General health screening was done at 38.7% of the sample industries in 1993 and at 44.6% in 1994. But the implementation rate of specific health screening decreased from 72.4% in 1993 to 64.6% in 1994. 3. The implementation rate of specific health screening was analyzed by some health factors. The rate of suspended particle increased from 61.8% in 1993 to 91.2% in 1994. But the rates of the others-noise, organic solvent, heavy metal, specific chemical substances-decreased. 4. Above grade C rate in health screening increased from 27.8% in 1993 to 35.5% in 1994. But that of endocrine disorders and pulmonary disease decreased.

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Product Design and Manufacture on Safety Hook and X-jog for application in Hoist and Crane (호이스트 및 크레인에 적용 가능한 안전후크와 X-jog 제품 설계 및 제작)

  • Na, Hyun-Ho;Kim, Do-Jung;Choi, Ju-Seok;Oh, Woo-Jun;Park, Jae-Woong;Lee, Chon-Ho
    • Journal of the Korean Society of Marine Environment & Safety
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    • 제21권1호
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    • pp.91-96
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    • 2015
  • In this study, we performed a study on prevention of the escape hoist heavy objects on the basis of the case of a disaster occurring during crane operations. A safety hook of the automatic fastening and coupling method by the conventional coupling method, the weight of the outside consisting of a combination of a safety ring structure was designed and manufactured. The main mechanism three-dimensional detail design and structural analysis confirmed the structure and stability of small strain than the allowable stress of the Safety Hook with X-jog through. Safety factor was confirmed to represent the average 1.5 to 1.2 higher than the safety factor to be considered in the general design structure. Therefore, Safety Hook and X-jog in the present study is to be operated upon structural stability is a structure attached to the hoist and crane are considered sufficient.

Feasibility Study of Improved Train Control System Using On-board Controller for Intelligent Control of Trackside Facilities (선로변 시설물의 지능적 제어를 위한 차상중심 열차제어시스템 시뮬레이션 기반 성능 평가)

  • Baek, Jong-Hyen;Jo, Hyun-Jeong;Chae, Eun-Kyung;Choi, Hyun-Young;Kim, Yong-Gyu
    • Journal of the Korean Society for Railway
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    • 제16권6호
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    • pp.528-533
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    • 2013
  • To improve the efficiency and safety of railway systems, the train control system has considerably evolved from the ground-equipment-based control system (e.g. track circuit, interlocking system, etc.) into the on-board-equipment-based control system. In addition, this train control system enables the rolling stock to intelligently control the trackside facilities by introducing information and communication technologies (ICT). Accordingly, since the ICT-based train control system simplifies the railway system (i.e. the heavy ground-equipment can be removed), an efficient and cost-effective railway system can be realized. In this paper, we perform a feasibility test of the ICT-based train control system using a simulation. To this end, we implement a test-bed consisting of prototype machines of on-board/ground equipment and introduce an integrated operation scenario for the train control. The simulation results satisfy all the requirements of train operation according to the scenario and show the effectiveness of the proposed train control system.