• 대한건축학회논문집:구조계
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• 제34권5호
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• pp.35-42
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• 2018

In order to seek out methods to reduce safety accidents caused by construction machinery and equipment, this study collects data about safety accidents and draws main risk factors by construction from the data, through SNA. It aimed to suggest safety management points to be used in future construction fields, by analyzing risk index of such factors. The finding can be summarized: First, Backhoe Bucket is the risk factor for crash accidents of average workers in earth works; boring machines-maintenance is the risk factor for fall accidents of construction machinery operators in foundation works; bending machine-reinforcing rod processing is the risk factor for jamming accidents of reinforcing rod engineers in frame works; and mobile crane-hook is the risk factor for crash accidents of average workers in lifting works. Second, works can be arranged in turn, according to the risk index: earth, lifting, frame and foundation works. Risk factors can be also arranged according to the risk index: Backhoe in earth works, pile drivers in foundation works, bending machines in frame works and mobile cranes in lifting works. This study has some limits, in that it only analyzed main machinery/equipment, among various kinds of them, for earth, foundation, frame and temporary works (lifting works) and used data collected over three years. Therefore, it is necessary to conduct an analysis using big data, by collecting additional data about a lot of machinery/equipment in future construction fields.

• 콘크리트학회지
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• 제8권2호
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• pp.70-74
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• 1996

• International Journal of Precision Engineering and Manufacturing
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• 제4권2호
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• pp.71-76
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• 2003

A virtual machine tool (VMT) is presented in this two-part paper. In Part 1, the analytical foundation for a virtual machining system is developed, which is envisioned as the foundation for a comprehensive simulation environment capable of predicting the outcome of cutting processes. The VHT system undergoes "pseudo-real machining", before actual cutting with a CNC machine tool takes place, to provide the proper cutting conditions for process planners and to compensate or control the machining process in terms of the productivity and attributes of the products. The attributes can be characterized by the machined surface error, dimensional accuracy, roughness, integrity, and so forth. The main components of the VMT are the cutting process, application, thermal behavior, and feed drive modules. In Part 1, the cutting process module is presented. When verified experimentally, the proposed models gave significantly better prediction results than any other methods. In Part 2 of this paper, the thermal behavior and feed drive modules are developed, and the models are integrated into a comprehensive software environment.vironment.

• 한국정밀공학회지
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• 제18권11호
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• pp.74-79
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• 2001

In this two-part paper, a virtual machine tool (VMT) is presented. In part 1, the analytical foundation of a virtual machining system, envisioned as the foundation for a comprehensive simulation environment capable of predicting the outcome of cutting processes, is developed. The VMT system purposes to experience the pseudo-real machining before real cutting with a CNC machine tool, to provide the proper cutting conditions for process planners, and to compensate or control the machining process in terms of the productivity and attributes of products. The attributes can be characterized with the machined surface error, dimensional accuracy, roughness, integrity and so forth. The main components of the VMT are cutting process, application, thermal behavior and feed drive modules. In part 1, the cutting process module is presented. The proposed models were verified experimentally and gave significantly better prediction results than any other method. The thermal behavior and feed drive modules are developed in part 2 paper. The developed models are integrated as a comprehensive software environment in part 2 paper.

• 한국공작기계학회논문집
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• 제12권3호
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• pp.52-57
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• 2003

In this paper, stability of ultra precision cutting unit is analyzed and this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for unit control.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.198-202
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• 2002

In this paper, stability of ultra precisio unit is analyzed, this unit is the kernel unit precision processing machine. According alteration of shape and material about stability investigation is performed. Through this stability investigation, trial is reduced in design and manufacture, at the time, we are accumulated foundation data for control.

• 소음진동
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• 제2권4호
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• pp.281-292
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• 1992

Two types of vibration problems are encountered in industrial field: active isolation and passive isolation. In a passive type of vibration isolation, a foundation of a delicated machinery such as TEM, SEM, inspection- probe test, photolithograph, etc. is designed to have a vibration amplitude lower than an acceptable limit. In an active type, the isolation is focused on the vibration reduction caused by the machine itself(pump, motor, press, compressor, etc.). The foundation for such a machine should be so designed as to reduce the transmitted vibration below the permissible level prescribed. At any case, a transmissibility and stability must to be considered. Since an active isolation type is aimed for a vibration source, it is useful to isolate the transmitted vibrations energy from a major vibration source at the specific location. In this paper, a designed methodology of double anti-vibration system has been examined in order to have low transmissibility and reliable stability. Also experiment of scale model behavior has been conducted. Finally, the experiment output of the transfer function is compared to the analytical data.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1630-1633
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• 2003

Hair pin bending machine is pipe forming machine consisting of heat exchanger product system. Hair pin produced by these machine is pathway of refrigerant and play a important role improving the performance and productivity of heat exchanger. The core technology of hair pin bending machine is forming the straight pipe into U-type without any defaults. Therefore, this paper study the relation between the pipe bending forming and the shape and position of mandrel using the elastic-plastic finite element analysis and provide a foundation technology for which developing the hair pin bending machine. The results are followed 1. Mandrel located in front of rotating center of bending die minimized the circular shape variation of copper pipe. 2. Diameter change of mandrel hardly effect the pipe shape.

• International Journal of Computer Science & Network Security
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• 제22권12호
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• pp.229-238
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• 2022

Due to digitization, data has become a tsunami in almost every data-driven business sector. The information wave has been greatly boosted by man-to-machine (M2M) digital data management. An explosion in the use of ICT for farm management has pushed technical solutions into rural areas and benefited farmers and customers alike. This study discusses the benefits and possible pitfalls of using information and communication technology (ICT) in conventional farming. Information technology (IT), the Internet of Things (IoT), and robotics are discussed, along with the roles of Machine learning (ML), Artificial intelligence (AI), and sensors in farming. Drones are also being studied for crop surveillance and yield optimization management. Global and state-of-the-art Internet of Things (IoT) agricultural platforms are emphasized when relevant. This article analyse the most current publications pertaining to precision agriculture using ML and AI techniques. This study further details about current and future developments in AI and identify existing and prospective research concerns in AI for agriculture based on this thorough extensive literature evaluation.

• Steel and Composite Structures
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• 제17권4호
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• pp.453-470
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• 2014

This article is the result of an investigation on the influence of a Pasternak elastic foundation on the stability of exponentially graded (EG) cylindrical shells under hydrostatic pressure, based on the first-order shear deformation theory (FOSDT) considering the shear stresses. The shear stresses shape function is distributed parabolic manner through the shell thickness. The governing equations of EG orthotropic cylindrical shells resting on the Pasternak elastic foundation on the basis of FOSDT are derived in the framework of Donnell-type shell theory. The novelty of present work is to achieve closed-form solutions for critical hydrostatic pressures of EG orthotropic cylindrical shells resting on Pasternak elastic foundation based on FOSDT. The expressions for critical hydrostatic pressures of EG orthotropic cylindrical shells with and without an elastic foundation based on CST are obtained, in special cases. Finally, the effects of Pasternak foundation, shear stresses, orthotropy and heterogeneity on critical hydrostatic pressures, based on FOSDT are investigated.