• 드라이브 ㆍ 컨트롤
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• 제11권2호
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• pp.22-29
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• 2014

This paper presents simulation-based analysis of energy flow of a wheel loader. The objective of this study is to analyze the energy flow of a wheel loader during driving and working. Because the wheel loader powertrain consists of a mechanical and hydraulic powertrain, the generated power from the engine is divided into 2 powertrains. Further, a virtual prediction of energy flow in the powertrains is a key factor in terms of optimal design. Accordingly, the simulation model that is able to predict the virtual energy flow is developed and analyzed in this study. The proposed wheel loader simulation model has been constructed in the Matlab/Simulink environment. It is expected that the developed simulation model will analyze the energy flow and efficiency in the design stage.

• Environmental Engineering Research
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• 제24권2호
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• pp.211-219
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• 2019

Since improper management practices of solid medical waste (SMW) could potentially result in serious health risks and environmental problems, it is very important to properly treat and dispose of the medical wastes. In this study, current practices of SMW management from storage to final disposal stage in 12 health care facilities (HCFs) of Burundi were investigated using the official government reports. The results showed that 75% and 92% of HCFs used uncovered wheelbarrows and trucks for on-site or off-site SMW transportation, respectively, indicating that most transportation equipment and waste workers are not safely protected. The results also showed that 92.8% of SMW (15,736.4 ton) from all 12 HCFs were inappropriately disposed of through uncontrolled land disposal and incineration. If pharmaceutical wastes and discarded medical plastics (29.5% of SMW) can be separated and treated properly, the treatment costs can be reduced and resource savings can be achieved. Raising awareness of healthcare workers and general public about potential health effects arising from improper SMW management, sufficient financial and human resources for the treatment facilities (especially incinerators), and effective regulations and guidelines for transportation and treatment of SWM are some of the major tasks for safe and sustainable medical waste management in Burundi.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2014년도 춘계학술대회
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• pp.595-598
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• 2014

최근의 사이버 공격은 보안패치가 발표되기 이전의 보안취약점을 악용하는 제로 데이(Zero Day) 공격, 웹 사이트를 대상으로 한 공격이 주를 이루고 있다. 이러한 공격은 소프트웨어 자체에 내장된 보안취약점을 이용하는 것이 대부분으로, 특히나 소스코드의 보안취약점을 이용한 사이버 공격은 보안장비로는 대응이 어려운 특성을 가진다. 따라서 이러한 공격을 예방하기 위해 소프트웨어를 구현하는 단계에서부터 보안취약점을 배제 시켜야한다. 본 논문에서는 구현단계에서부터 보안위협을 해소하는 Secure Coding 가이드 지원 도구를 설계하고자 한다.

• 한국산업융합학회 논문집
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• 제22권2호
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• pp.125-135
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• 2019

In recent years, the digital transformation age represented by the "Fourth Industrial Revolution", which is a universalization of digitalization across all industries, has become a reality. In the construction sector in 2018, the Ministry of Land, Infrastructure and Transport established the Smart Construction 2025 vision and established the 'Smart Construction Technology Roadmap' aiming to complete construction automation by 2030. Especially, in the construction stage, field monitoring technology using drones is needed to support construction equipment automation and on-site control, and a 3D geospatial information model can be utilized as a base tool for this. The purpose of this study is to investigate the factors affecting earthworks work in order to manage changes in site conditions and improve communication between managers and workers in the earthworks plan, which has a considerable part in terms of construction time and cost as a single type of work. Based on this, field management procedures and applications were developed.

• 한국기계가공학회지
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• 제19권11호
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• pp.64-69
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• 2020

To determine the effective factors for microparticle blasting with precise sequence position control in the x-axis and y-axis directions, we conducted a statistical experimental analysis of blasted square shapes by considering five condition factors. The control input and output were operated simultaneously by rotation-linear motion conversion and fine particles were blasted onto the aluminum specimen by precise position control driving using multiple execution codes. The micro-driving device used for processing was capable of microparticle blasting and of controlling the system through contact with a limit sensor at high speed and a two-degree-of-freedom driving mechanism. Our experiments were conducted on 1,050 specimens of pure aluminum (containing <1% of other elements). The effects of several factors (e.g., particle and nozzle diameters, blasting pressure, and federate and blasting cycle numbers) on the surface roughness and blasted surface's depth were verified through a statistical experimental analysis by applying the dispersion analysis method. This statistical analysis revealed that the nozzle diameter, the blasting pressure, and the blasting cycle number were the dominant factors.

• 한국안전학회지
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• 제37권6호
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• pp.71-80
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• 2022

Since the 2000s, the demand for private demolition works has been gradually increasing as the apartment housing market has been led by redevelopment and reconstruction. In the case of the military, the Ministry of National Defense is consolidating troops from each military unit to reorganize the unit structure in accordance with Defense Reform 2.0; the plan includes reducing the garrison used by each unit to 70% of its current level. Accordingly, the demand for demolition work in the military is also expected to increase. However, the military regulations do not reflect the relevant laws that have been revised recently. This study identifies regulations and system improvements for demolition work suitable for the military based on an analysis of accident cases that have occurred during demolition work, of domestic and foreign laws and regulations related to military demolition work, and of the problems with current military safety management at each stage of planning, design, and construction. The study subsequently proposes improvements for military demolition work, including budget execution adjustment, the establishment of training courses, on-site inspections, the development of guidelines for military demolition work, the provision of risk assessment standards, and the need for the qualification of equipment operators.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.983-989
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• 2009

This study aims to systematically identify direct and indirect factors that influence labor productivity and to build a model that mathematically quantifies them so as to efficiently manage and increase labor productivity in the construction work. This study was performed based on the productivity model for workers in reinforced concrete construction projects, because it aims to establish a general construction labor productivity model that reflects many factors that influence labor productivity. Using statistical analysis, we found that the components that significantly influence productivity were the worker component, the work characteristic component, the work technique component, the work management component, the equipment & materials component, and the work guide component, while the work delay components did not significantly influence productivity. In addition, a priority analysis was performed based on the components that showed statistically significant effects. The results of the analysis indicated that the influence of work management component and the work technique component is more than that of the worker component and the work characteristic component. The construction labor productivity model that was formulated in this study could be used for the determining the standard productivity during the initial planning stage, so the best strategy for increasing labor productivity could be formulated.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 가을 학술논문 발표대회
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• pp.175-176
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• 2020

As the concrete pouring work relies on manual work, there is a lot of room for automated equipment development. In this study, as a basic study on the development of an automated system for pouring concrete, the trend of patent applications by year, country and detailed technology was investigated. Related technologies were classified into screed automation, CPB automation, and concrete pouring integrated system to analyze patent application trends. As a result, since 1999, patent applications have been steadily in progress, repeating increases and decreases in Japan, Korea, the United States, and Europe. In addition, the growth stage of the market is in the early stages of maturity, and patent applications for related technologies are expected to continue. In the future, based on the patent application trend analyzed in this study, the development direction of the automated concrete pouring system will be reviewed and the redundancy of similar technologies will be reviewed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 가을 학술논문 발표대회
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• pp.188-189
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• 2021

The technology of manufacturing freeform molds with S-LOM based 3D printer has advantages in the production period and the curvature range. However, there is no any support tool about productivity analysis of S-LOM technology because S-LOM technology is early-stage technology. There can be problems about increase of construction time and cost without any decision support tool like productivity analysis models etc. Therefore, in this study, the productivity analysis simulation model for freeform formwork based on S-LOM technology was developed using ARENA software. The process and logic of manufacturing freeform molds can be easily visualized in this model. Futhermore, the resource like labor, equipment and material can be easily optimized with this model. As a result, it can contribute to preventing the increase of construction time and cost in formwork with further productivity analysis.

• 풍력에너지저널
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• 제15권1호
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• pp.11-20
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• 2024

As the generation capacity of floating offshore wind turbines increases, the wind load applied to each turbine increases. Due to such a high wind load, the capacity of transport equipment (such as tugboats or cranes) required in the transportation and installation phases must be much larger than that of previous small-capacity wind power generation systems. However, for such an important wind load prediction method, the simple formula proposed by the classification society is generally used, and prediction through wind tunnel tests or Computational Fluid Dynamics (CFD) is rarely used, especially for a concept or initial design stages. In this study, the wind load of a 10 MW class floating offshore wind turbine was predicted by a simplified formula and compared with results of wind tunnel tests. In addition, the wind load coefficients at each stage of fabrication, transportation, and installation are presented so that it can be used during a concept or initial design stages for similar floating offshore wind turbines.