• Korean Journal of Materials Research
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• v.21 no.7
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• pp.364-370
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• 2011

Currently, there are two main issues regarding the development of core technologies in the automotive industry: the development of environmentally friendly vehicles and securing a high level of safety in the event of an accident. As part of the efforts to address these issues, research into alternative materials and new car body manufacturing and assembly technologies is necessary, and this has been carried out mainly by the automotive industries. Large press molds for producing car body parts are made of cast iron. With the increase of automobile production and various changes of design, the press forming process of car body parts has become more difficult. In the case of large press molds, high hardness and abrasive resistance are needed. To overcome these problems, we attempted to develop a combined heat treatment process consisting of local laser heat treatment followed by plasma nitriding, and evaluated the characteristics of the proposed heat treatment method. From the results of the experiments, it has been shown that the maximum surface hardness is 864 Hv by the laser heat treatment, 953 Hv by the plasma nitriding, and 1,094 Hv by the combined heat treatment. It is anticipated that the suggested combined heat treatment can be used to evaluate the durability of press mold.

• International Journal of Human Ecology
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• v.16 no.2
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• pp.1-9
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• 2015

This study investigated the effects of persimmon-dyed clothing materials upon thermophysiological responses and subjective comfort sensations during exercise and rest in a warm environment. Six healthy, untrained women participated in two separate testing sessions, with cotton materials dyed with astringent persimmon extract (DC) and undyed cotton materials (UDC). The physical characteristics associated with heat and moisture transfer were improved in DC; also, stiffness, anti-drapery stiffness and crispness in the primary hand values were higher in DC. The experimental protocol consisted of a 10-min rest, 15-min exercise on a treadmill (at ${7km{\cdot}h^{-1}}$) and 25-min recovery at $28{\pm}0.2^{\circ}C$ and $50{\pm}3%\;RH$. The results were as follows: When wearing DC rather than UDC, mean body temperature, heart rate, heat storage and body mass loss were significantly lower during the whole experimental period. Clothing microclimate temperature showed different profiles between the two clothing materials, being lower with DC than UDC during the first half of exercise and the second half of recovery. Clothing microclimate humidity was significantly lower with DC than UDC during the whole experimental period. When wearing UDC, subjects felt significantly warmer and less comfortable during exercise, and sensed greater humidity during exercise and recovery. These results suggest that eco-friendly clothing materials dyed with astringent persimmon extract can reduce exercise-induced heat load and improve subjective sensations when exercising and resting in a warm environment, due to greater heat dissipation from the body to the outside environment compared with undyed clothing materials.

• Journal of the Korean Society of Costume
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• v.57 no.7
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• pp.137-152
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• 2007

The purpose of this study is to research on concept, consisting factors, and specialties of theme park' character costumes to understand better about character costumes as well as to establish fundamental research data. The characteristics of character costumes in the theme park are as follows. First, theme park' character costumes are personified so that visitors may feel friendly and have emotional communication with them. Specially, costume that anthropomorphize an animal(85.3%) and silhouette of lozenge style(86.8%) dominated the highest weight. Animal figures are walking upright and wearing human's clothes. They communicate with visitors using mime actions. Second, various types of body proportion is applied to highlight the characteristics of character costume. Most character costumes are applied with unrealistic body proportion. This unrealistic body proportion give abnormal image and looks funny. The important factor is size of their head. Especially, 3.5 body proportion(78.9%) is general. Third, simplification, exaggeration, shrinkage, and modification are other factors. Simplification is applied differently by parts. Pocket, collar details are simplified to clarify the character's image. More simplification can lead to ommission. For their head, peculiar parts look stand out but other parts are simplified to stress their characteristics. Exaggeration is used with shrinkage to give strong impression to visitors. Forms are broken intentionally and they are modified. They look impressive because they are not harmonized. It is unexpected image and induces humor and familiar feelings. Matter of stylization includes exaggeration, shrinkage, modification and movement of actors that have tangible factor of character costume.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.225-234
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• 2020

Reliability-based structural optimization usually requires designers or engineers model different designs manually, which is considered very time consuming and all possibilities cannot be fully explored. Otherwise, a lot of time are needed for designers or engineers to learn mathematical modeling and programming skills. Therefore, a framework that integrates generative design, structural simulation and reliability theory is proposed. With the proposed framework, various designs are generated based on a set of rules and parameters defined based on visual programming, and their structural performance are simulated by OpenSees. Then, reliability of each design is evaluated based on the simulation results, and an optimal design can be found. The proposed framework and prototype are tested in the optimization of a steel frame structure, and results illustrate that generative design based on visual programming is user friendly and different design possibilities can be explored in an efficient way. It is also reported that structural reliability can be assessed in an automatic way by integrating Dynamo and OpenSees. This research contributes to the body of knowledge by providing a novel framework for automatic reliability evaluation and structural optimization.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.22 no.4
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• pp.170-177
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• 2012

Amethyst gems represents thermal effects of far-infrared emission, promotes the body's metabolism, and attracts attention as an eco-friendly interior material. In this paper, amethyst increase the value of jeweling by applying the characteristic purple motif, furthermore, I will intend to develop of design model. Metal crafting of brooch & necklace in the works performed based on the organic three-dimensional shape of the Rhino CAD Data. It was made possible through the precise laminated wax processing and then combining the amethyst. I researched the ornament modeling by applying the 'Golden Ratio', and suggesting utilizing method for interior jewel modeling, and also, is expected that this paper on the amethyst modeling design can contribute to the manufacturers' productivity.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.5
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• pp.51-59
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• 2001

This paper presents a design of the Dasan Children\`s Park which is located Shindang- dong, lung-gu, Seoul which has an area of about 3,678$m^2$. Objectives for the design were to make nature-friendly space, learning space, interesting play space, space for every child, adventure play space, traditional play space, sense of place, and recycle space. For the space compositions a children\`s garden, a traditional play space, and a science play space were located around the S shaped main route. Facilities relating nature, science, culture. environment and adventure play were arranged in the 3 main spaces. The Children\`s Garden is a green space for learning and playing with natural elements. It is composed of a ecological learning space, a children\`s story garden, a children\`s song road, an environmental labyrinth, and a pall space leer handicap children. The Science Play Place is a place space for learning scientific theories through plays to which scientific theories were applied. It is composed of a total play structure, a math experience playground, a \"Keojunggi\" play space, a sound reflecting experience space, arid an infant playground. The Traditional Play Madang(space) is a space for traditional plays. It is composed of a traditional play pattern, a sun dial, and a floor fountain. The Recycle Road is a dragon shaped road fort learning about resource recycling and conservation. It is composed of a dragon head, body, tail space and a dragon bead(cint mani).int mani).

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.2035-2040
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• 2008

The electrical discharge of high voltage direct current(HVDC) overhead transmission line generate audible noise, radio noise, electric field, ion current and induced voltage on the ground. These items are major factors to design environmentally friendly configuration of DC transmission line. Therefore, HVDC transmission lines must be designed to keep all these corona effects within acceptable levels. Several techniques have been used to assess interference caused by ions on HVDC overhead transmission line. In this study, to assess the ion characteristic of DC line, the ion current density and induced voltage caused by ion flow were measured by plate electrodes manufactured from a metal flat board and charged bodies, respectively. The charged body has two types of cylinder and cylindrical plate. From the results of calibration experiments, the sensitivity of flat electrode and charged body can be obtained. At present, the developed system is used to investigate the ion generation characteristics of Kochang DC ${\pm}500kV$ test line.

• Journal of Power System Engineering
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• v.7 no.3
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• pp.48-53
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• 2003

This paper deals with the control of a horizontally placed flexible rotor levitated by electromagnets in a multi-input/multi-output (MIMO) active magnetic bearing(AMB) system. AMB is a kind of novel high performance bearing which can suspend the rotor by magnetic force. Its contact-free manner between the rotor and stator results in it being able to operate under much higher speed than conventional rolling bearings with relatively low power losses, as well as being environmental-friendly technology for AMB system having no wear and no lubrication requirements. In this MIMO AMB system, the rotor is a complex mechanical system, it not only has rigid body characteristics such as translational and slope motion but also bends as a flexible body. Reduced order nominal model is computed by consideration of the first 3 mode shapes of rotor dynamics. Then, the $H_{\infty}$ control strategy is applied to get robust controller. Such robustness of the control system as the ability of disturbance rejection and modeling error is guaranteed by using $H_{\infty}$ control strategy. Simulation results show the validation of the designed control system and the modeling method to the rotor.

• Design & Manufacturing
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• v.16 no.2
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• pp.46-52
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• 2022

As the consumer market in the eco-friendly vehicle industry grows, the demand for water pump in a electric car parts market. This study intend to propose a mathematical model that can verify the effect of improving thermal properties when a non-conductive cooling filler liquid is introduced into an electric vehicle water pump. Also, the pros and cons of the immersion cooling method and future development way were suggested by analyzing the cooling characteristics using on the derived analysis solution. Thermal characteristics analysis of electric water pump applied with non-conductive filler liquid was carried out, and the diffusion boundary condition in the motor body and the boundary condition the inside pump were expressed as a geometric model. As a result of analyzing the temperature change for the heat source of the natural convection method and the heat conduction method, the natural convection method has difficulty in dissipating heat because no decrease in temperature due to heat release was found even after 300 sec. Also, it can be seen that the heat dissipation effect was obtained even though the non-conductive filling liquid was applied at the 120 sec and 180 sec in the heat conduction method. It has proposed to minimize thermal embrittlement and lower motor torque by injecting a non-conductive filler liquid into the motor body and designing a partition wall thickness of 2.5 mm or less.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.53-61
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• 2023

The biggest core task in the new modern automobile industry lies in the development of eco-friendly vehicles with the goal of 0% emissions by the EU by 2035. Accordingly, in an era where the industry is rapidly changing with electric vehicles, education and training on EV electric vehicles are urgently needed. In this study, by developing a core EV powertrain system simulator excluding the chassis platform (body, tire, etc.) used identically to existing internal combustion locomotives, Understand the EV powertrain system, including mechanical engineering, electrical engineering, and electronic engineering applications. Through this course, we intend to use it as a medium to develop engineering and convergence development capabilities.