• 한국정밀공학회지
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• 제26권4호
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• pp.120-127
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• 2009

Spindle units of machine tool are very important part in the manufacturing area. Recently high speed machining has become the main issue of metal cutting. To develop high speed machine tools, a lot of studies have been carried out for high speed spindle. Due to increase of the rotational speed of the spindle, there has been renewal of interest in vibration of spindle. This paper concerns the improvement of spindle design using design of experiments. To improve the design of critical speed and weight of spindle, the experiments using central composite method have been carried out. The targets are critical speed and weight of spindle. For optimization of critical speed and weight and optimization of only critical speed by operation of all area search through response optimizer, the result of analysis has improved design of each factor. Finite element analyses are performed by using the commercial codes ARMD, CATIA V5 and ANSYS workbench. From the results, it has been shown that the proposed method is effective for modification of spindle design to improve critical speed and weight.

• 한국CDE학회논문집
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• 제8권4호
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• pp.222-230
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• 2003

Artificial intelligence has been used in the configuration design stage of high-speed train. The traction system of a high-speed train is composed of transformers, motor blocks, and traction motors of which locations and number in the trainset should be determined in the early stage of the train conceptual design. Components of the traction system are heavy parts in the train, so it gives strong influence to the top speeds and overall train configuration of high-speed trains. Top speeds have been predicted using the neural network with the associated data of the traction system. The neural networks have been learned with data sets of many commercially operated high-speed trains, and the predicted results have been compared with the actual values. The configuration design of the train set of a high-speed train determines the basic specification of the train and layout of the traction system. The neural networks is a useful design tool when there is not sufficient data for the configuration design and we need to use the existing data of other train for the prediction of trainset in development.

• 교통기술과정책
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• 제6권1호
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• pp.155-170
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• 2009

In an effort to increase the operational efficiency of highways, South Korea has been increasing its design speed recently. However, the use of higher design speed will also increase construction costs. Moreover, increasing the design speed is expected to have an impact on safety. Hence, there is a strong need to demonstrate that the benefits outweigh the cost of having a higher design speed. This study surveyed a sample of design engineers to determine their awareness of the consequences of increasing design speed and their assessment of the right design speed for an actual rural arterial. In addition to the survey, a case study of three recently upgraded highways was conducted to determine the changes in traffic volumes, speeds, travel times, and safety.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.156-163
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• 2005

This study was attempted to provide some fundamental data for safety structrural design of biological production facility. Wind load and snow load, acting on agricultural structures is working more sensitive than any other load. Therefore, wind speed and snow depth according to return periods for design load estimation were calculated by frequency analysis using the weather data(maximum instantaneous wind speed, maximum wind speed, maximum depth of snow cover and fall) of 68 regions in Korea. Equations for estimating maximum instantaneous wind speed with maximum wind speed were developed for all, inland and seaside regions. The results were about the same as the current eqution in general. Design wind speed and snow depth according to return periods were calculated and Local design wind load and snow load depending on return periods were presented together with iso-wind speed and iso-snow depth maps. The calculated design snow depth by maximum depth of snow cover were higher than design snow depth by maximum depth of snow fall. Considering wind speed and snow depth, protected cultivation is very difficult in Ullungdo, Gangwon seaside and contiguity inland regions, and strong structural design is needed in the west-south seaside against wind speed, and structure design of biological production facility in these regions need special consideration.

• 조명전기설비학회논문지
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• 제22권3호
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• pp.59-65
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• 2008

High-speed electrical motor has been studied for several applications, i.e. for direct-drive systems of centrifugal compressors and turbo blowers. This paper deals with a design consideration of electromagnetic, mechanical and thermal limits of high-speed induction motor for turbo blower. Basic design concept of high-speed motor was proposed. As the motor is to be operated at high speed, the losses are quite different from conventional low-speed machines. Especially, the increases of rotor eddy current and friction losses could lead to an overheated motor. So, we suggested a special cooling system to reduce temperature rise. And, based upon this design concept, the prototype induction motor(37[kW], 45,000[rpm]) for high-speed turbo blower was designed and 2-D electromagnetic field analysis was implemented. Finally, criteria to evaluate the characteristics of high-speed induction motor have been proposed and tested.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 추계학술대회 논문집
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• pp.130-138
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• 1999

This study was carried out about interior design of trailer car for Korean High speed Train of Maximum operating speed of 350km/h. The interior main item design of high speed train is performed in order to satisfy the function of speed, safety and comfort concerning the RAMSH, ENVIRONMENT, ACTIVITY AND INFORMATION, This paper focuses on what is the design principle concerning the above mentioned factors and how did we apply that in the korea high speed train.

• 대한기계학회논문집A
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• 제27권12호
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• pp.2028-2038
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• 2003

High-speed feed drive systems have been widely used in the manufacturing and semiconductor industries. Specifications for high-speed systems require more advanced capabilities than conventional feed drive systems. It is necessary to devise special design concepts to achieve the level of performance for high-speed feed drive systems. In this paper, an integrated design method is proposed for high-speed feed drive systems in which the interactions between mechanical and electrical subsystems ought to be considered simultaneously during the design process. Based on the integrated design method, a nonlinear optimal design procedure of mechanical subsystems considering the Abbe and radius errors is accomplished through the design process of electrical subsystems satisfying the control stability and the saturation condition of actuators as well as the relative stability. Both mechanical and electrical parameters are considered as design variables. Simulations and numerical case studies show that the integrated design method of high-speed feed drive systems creates results satisfying the desired performances of mechatronic systems.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2005년도 춘계학술대회 논문집
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• pp.285-290
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• 2005

In this paper, the general process of the conceptual design of high speed train system was introduced by the review of the design process of Korea High Speed Train. The development of a general design process of high speed train is necessary in order to lead a high speed railway market in the future. For the conceptual design of high speed train system, the goals to develop a new high speed train are set. The different high speed train configurations are chosen regarding traction power, bogie type, etc and repeatedly evaluated with respect to the requirements

• 한국도로학회논문집
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• 제12권2호
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• pp.25-31
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• 2010

현 도로설계기준은 설계속도에 기반하여 선형설계에 관한 지침을 제시하고 있으며, 이는 설계속도가 도로 공용 후에 운전자의 주행 속도와 거의 동일할 것임을 전제하고 있다. 도로 평면 곡선부의 설계도 주어진 설계속도에 따라 운전자가 쾌적성을 유지한 채 통과할 수 있는 최소곡선반경을 기준으로 제시하고 있다. 그러나 쾌적성에 기초한 횡방향 미끄럼마찰계수는 실제 습윤노면에서 관측되는 물리적인 횡방향 미끄럼마찰계수보다 낮기 때문에 기준에 제시된 곡선반경은 최소의 의미보다는 권장 값으로 보는 것이 합리적이다. 아울러, 최소곡선반경보다 여유로운 설계 값을 선호하는 실무관행으로 도로 공용 후 운전자의 주행속도는 설계속도를 상회하여 설계속도가 주행속도를 대표하지 못하는 결과를 초래하고, 결과적으로 현 설계기준의 주요전제를 위반하게 될 것으로 본다. 이러한 연구 가정을 검토하기 위해 지방부 도로에서 노면 미끄럼 마찰계수와 운전자의 주행속도를 조사하였다. 연구결과로, 쾌적성에 기반한 미끄럼 마찰계수와 물리적인 미끄럼마찰계수와의 차이에 따른 안전여유를 정량적으로 제시했고, 안전여유 및 설계관행에 따른 여유로운 설계로 인해 설계속도와 주행속도 간에 괴리가 발생함을 제시했다. 이를 토대로, 현 설계속도 기반의 선형설계는 최소기준과 더불어 설계속도와 주행속도 사이의 괴리를 최소화할 수 있는 선형 설계 관리 방안이 마련될 필요가 있다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집 특별세미나,특별/일반세션
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• pp.517-524
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• 2009

This paper proposes a magnetic analysis model and design method of transformer for the high-speed EMU. It has a many part of the consideration in design because the transformer in high-speed train has the multiple output. Also the output characteristic, weight, and size of transformer is an important factor. This research proposes a design method of transformer in high-speed EMU. And it is easy to design by using the analysis model in design the transformer through the establishment of the magnetic analysis model.