• Journal of Drive and Control
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• v.15 no.3
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• pp.49-56
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• 2018

Construction machinery is used to improve productivity in civil engineering work and construction work, and it is a lengthy operation, and consumes considerable fuel to cope with large loads. As a result, productivity and fuel consumption of the construction machine become the main deciding factors. In the hydraulic system of the excavator, the main control valve is the most critical position for control. The flow distribution for control performance is achieved by the metering orifice, that causes critical energy loss. To improve this, we propose a combination of a three port proportional pressure reducing valve and a poppet type flow control valve as an IMV to replace the existing spool type MCV. To validate the proposal, we analyze static characteristics by modeling mathematically, and analyze dynamic characteristics. Simulation using the AMESim software on the regeneration circuit of the boom cylinder up-down operation, verifies the energy-saving effect compared to the existing MCV when IMV is used.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2007.11a
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• pp.364-367
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• 2007

According to increase of construction projects which is accomplished in the town, diaphragm wall method was proposed. This method diminished noise and vibration. And it is able to excavate deeper than other methods. But excavation work is difficult to maintain vertical and requires much time to work. Also the work result depends on know-how, experience and intuition of excavating machine operator. We interviewed technical experts related with slurry wall method and find equipment's characteristics. We used cost-concern matrix to investigate the propriety for the introduction of trench cutter automation. Through the research, it is proper to apply trench cutter automation.

• Korean Journal of Construction Engineering and Management
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• v.10 no.2
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• pp.132-144
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• 2009

In this study, the basic data for calculating the proper construction cost as minimizing the uncertainty at the stage of forecasting construction cost with the basis of the analysis on the actual construction cost within completed domestic public apartment house. In this regard, 23 public apartment houses by each region which were ordered by the Korea National Housing Corporation and completed from 2004 to 2007 were selected as the objects of study. Four works such as common temporary installation, construction work, civil work and machine/equipment work which are the important direct cost items based on the actually inputted and settled construction costs were classified by completion year, region, architectural area, and the distribution type considering inflation rate. The sequent actual construction costs per 3.3m2 were compared and analyzed by each work, the proper construction costs were analogized and the calculating formula were presumed with the basis of average actual construction costs to be analyzed and presented.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.4
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• pp.1683-1691
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• 2013

Concrete surface grinding is frequently used for flatness of concrete surface, concrete pavement rehabilitation, and adhesiveness in pavement construction. The procedure is, however, labor intensive and has a hazardous work condition. Also, the productivity and the quality of concrete surface grinding highly depend on the skills of worker. Thus, the development of remote controlled concrete surface grinding equipment is necessary to prevent the environmental pollution and to protect the workers from hazardous work condition. However, it is difficult to evaluate the grinded surface objectively in a remote controlled system. Also, The machine vision system developed in this study takes the images of grinded surface with the network camera for image processing. Then, by representing the quality test results to the integrated program of the remote control station, the quality control system is constructed. The machine vision algorithm means the image processing algorithm of grinded concrete surface and this paper presents the objective quality control standard of grinded concrete surface through the application of the suggested algorithm.

• Journal of Drive and Control
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• v.16 no.4
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• pp.74-79
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• 2019

In this study, an edible fresh corn harvest testing machine was designed and manufactured. And harvesting performance was analyzed through the field test. The testing machine is of the tractor attached type. It is connected to the tractor PTO shaft to transfer power to the each part of the harvesting machine. And it harvests fresh corn by one row through the processes of cutting, stem crushing, detaching, and collecting. The performance test was performed at PTO speed (540, 750, 1050 rpm, respectively), working speed (0.1, 0.15, 0.2 m/s, respectively), and cropping cultivation (row spacing·hill spacing 70·25 cm, 70·40 cm, 90·30 cm, respectively). The performance test was repeated three times in the 15 m section. The detachment loss ratio, uncollected crop ratio, damage ratio, and harvest ratio were analyzed. As a result of the performance test, it was analyzed that the PTO speed 540 rpm, running speed of 0.1 m/s, and row spacing·hill spacing 70·40 cm were the optimal condition.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.48-53
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• 2017

Many construction accidents can be lead to a death occurring at construction sites. These are considerably due to potentially-hazardous equipment and machine or unexpected collapsion at earth work due to land slide and so on. Almost 50% of the total death and injury, occurred in construction sites in 2015. 66% of those serious accidents are due to falling occurring from construction sites when they work. Therefore, causes and recommendations of each accident should be deeply thought and analysed The indirect causes are directly related to safe consciousness of the construction workers. Actually, their safety consciousness are not high, even very low, it is thought. Questionnaire survey sheets have been distributed to Seoul, Incheon, and Gyunggi-Do area, first. And then, the authors have collected those directly at sites, in order to increase collection rate of the sheets. The totally, collected sheets are 295 sheets. And, they are analysed using SPSS version 19 package program. Workers internal consciousness has been investigated and reviewed and analysed by statistical method such as frequency rate, crossed, and correlated analysis. And finally the conclusions for the above analyses are as follows; Heavy weight worth a crew of more than two workers should be necessarily considered for the advanced safety plan and needed for making a highly potential hazard group at construction sites. Safety consciousness, earing p.p.e, workman ship should be mainly considered for investing safety costs with an aspect of human factor.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.1
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• pp.34-36
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• 1997

In this paper, we introduce the design method using CAE(Computer Aided Engineering) which is profitable in the compatibility and standardization of the developed product and the reduction of construction time and price to develop and design a machine equipment. Particularly, we select the standard model to design or develop from the large machinery to the super precision one, extract the peculiar characters of the model by the close analysis of the physical and technical part, can predict the previous result of experimental characteristics on objective dimensions through the analogical mathematical analysis, and can induce the design model demanded by user investigating optimal data in advance. We present the analogical algorithms and process method of design factors and restriction factors in the systematization design with computer. Then we analyze step functions for each systematization equipment and induce the process of technical data with actuator model.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.5
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• pp.717-722
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• 2013

The wastewater reclamation and reusing system has been rising as an alternative of water resource exhaustion that the whole world is experiencing. In order to be able to bring about improvement of the existing wastewater reclamation and reusing system, this research has developed of Conversion-Human Machine Interaction (C-HMI) based real-time control and monitoring system such as a sensor module and gate module, web monitoring system. This system was communication almost-error-free in various environment and situation. As a result, we have achieved our goal that has to doing work correctly as a sensor and gateway module that communication error is less than 0.2% throughout the embodied system and add that it can be easily controled and configured as an interface equipment to a complex sensor of water quality. According to this, the construction of a database capable of analyzing and assessing collection, storage and various elements of reliable water quality and flow rate data can be possible.

• Proceedings of the Korean Society of Computer Information Conference
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• 2022.07a
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• pp.635-636
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• 2022

대학·연구기관 등이 보유한 연구장비의 공동활용으로는 중소기업의 즉각적인 수요를 해결하기에는 역부족이다. 중소벤처기업의 다양한 요구를 실시간으로 충족시키기 어려우며, 이용비용, 이용절차 복잡, 예약대기 등의 애로사항이 많아 중소벤처기업은 민간의 리스업체를 선호하는 경향이 있다. 중소벤처기업은 연구개발을 위한 자체 보유 연구장비가 부족하여 자체시험, 설계분석 수행이 어려움에 따라 R&D 초기단계부터 애로가 발생하고 있다. 또한 중소기업이 외부 시험, 검사장비 활용 시 경제적 부담, 이용절차 복잡 등의 다양한 어려움을 겪고 있어 연구장비의 새로운 지원방식의 필요성이 제기되고 있다. 미국의 경우 민간 중심으로 연구장비 임대를 활성화하고 있고, 일본 및 유럽은 임대지원 정책을 추진하고 있으므로 우리도 이러한 리스뱅크 플랫폼의 구축이 시급한 실정이다. 따라서, 연구장비 임대, 공동활용 등 종합적인 서비스와 중소벤처기업이 이용하기 쉽고 편리한 전문가 시스템을 활용한 연구장비 리스뱅크 플랫폼 구축방안을 살펴보자.

• Journal of the Korean Society of Safety
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• v.34 no.3
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• pp.83-88
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• 2019

The 7,993 cases of Survey Report of Fatal Industrial Accidents conducted jointly by the MEOL and the KOSHA for the recent seven years(2007-2013) were categorized according to personal and occupational characteristics, industry types, business sizes, job types, activities at the time accident, types of accidents, material agents(assailing materials), unsafe conditions, and unsafe acts. And it is found that among the 72.2 percent of fatal occupational accidents in the construction and manufacturing industries are caused by falling, sticking, bumping and being caught under objects & overturning. For this study, through the empirical analysis on causes of fatal industrial accidents, was used to identity high risk groups based on total data of 7,993 victims of occupational accidents. An annual fatal occupational injury (FOI) rate per 10,000 workers was about 0.47‱. The middle-aged group and the elderly group showed the highest FOI rates per 10,000 workers (0.73‱, 0.80‱), and the daily workers showed the highest FOI rate (1.46‱), and the craft and related trades workers showed the highest FOI rate (2.17‱). In case of industry type the mining industry (7.26‱) showed the highest FOI rate, followed by the sewerage, waste management, materials recovery and remediation activity industry (3.91‱) and the construction industry (2.71‱). The primary high risk target group that requires a strategy designed to reduce fatal occupation injuries caused by falling and bumping & contact(collision) is the construction industry, and the secondary high risk target group in the construction industry is classified as the equipment, machine operating and assembling workers in the construction industry, those aged 50 years old and above need the prevention measures against bumping & contact(collision) and being caught under an object & falling(objects), while those aged less than 50 years old need prevention measures against falling(persons).