• Transactions of Materials Processing
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• v.32 no.3
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• pp.122-128
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• 2023

As electric vehicles (EV) have increasingly replaced the conventional vehicles with internal combustion engines (ICE), most of automotive makers are actively devoting to the technology development of EV parts. Accordingly, the manufacturing process for power source has been also shifting from engine/transmission to EV motor/reducer system. However, lack of experience in developing the EV motor still remains as a technical challenge. In this paper, we employed the forming simulation based on finite element modeling to solve this problem. In particular, in order to increase the accuracy of the forming simulation, we introduced the elastic-plastic constitutive model parameters for polymer-copper hybrid wire by investigating the individual strain-stress curves, and elastic modulus of polymer and copper. Then, the reliability of modeling procedure was confirmed by comparing the simulated results with experiments. Finally, the identified mechanical properties and finite element modeling were applied to a hairpin forming process, which involves multiple deformation paths such as bending, pressing, widening, and twisting. The proposed numerical approach can replace common experience or experiment based trials by reducing production time and cost in the future.

• Journal of the Institute of Convergence Signal Processing
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• v.25 no.2
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• pp.113-118
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• 2024

Recently, advancements in artificial intelligence and computer graphics technology have led to the emergence of various virtual humans across multiple media such as movies, advertisements, broadcasts, games, and social networking services (SNS). In particular, in the advertising marketing sector centered around virtual influencers, virtual humans have already proven to be an important promotional tool for businesses in terms of time and cost efficiency. In Korea, the virtual influencer market is in its nascent stage, and both large corporations and startups are preparing to launch new services related to virtual influencers without clear boundaries. However, due to the lack of public disclosure of the development process, they face the situation of having to incur significant expenses. To address these requirements and challenges faced by businesses, this paper implements a photogrammetry-based facial capture system for creating realistic virtual humans and explores the use of these models and their application cases. The paper also examines an optimal workflow in terms of cost and quality through MetaHuman modeling based on Unreal Engine, which simplifies the complex CG work steps from facial capture to the actual animation process. Additionally, the paper introduces cases where virtual humans have been utilized in SNS marketing, such as on Instagram, and demonstrates the performance of the proposed workflow by comparing it with traditional CG work through an Unreal Engine-based workflow.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.378-379
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• 2012

Nowadays, great energy consumption in advanced electrical industry has called up the great y efficiency. Electric power IT industry such as intelligent electric power system is receiving great attention and being marked up as a new growth engine. Through Intelligent electric power system, the electric power supply can be balance optimized according to demand, giving huge cost savings advantage for energy imports, infrastructure construction and operation. Nevertheless, the intelligent system promotes better reliability in power supply. Manual electric power management using man power appears to be non-practical. Real time electric power management on all facilities and equipment can be done through an intelligent electric power system, any accident break out issue can be easily recorded and recognized. In this paper, a fully integrated intelligent switchgear electric management system is developed to monitor and remote control the electrical switch based on smart phone. The proposed system is superior than the existing switchgear management system's weakness and can sharply improve effectiveness and stability with low cost. In future, the proposed system is expected to be greatly contributed to the advancement of the IT industry in electric power management.

• Journal of Digital Contents Society
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• v.18 no.3
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• pp.607-612
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• 2017

The use of RaspberryPi in building an embedded system may be difficult for users in understanding the circuit and the hardware cost. This paper proposes a solution that can test the systems virtually. The solution consists of three elements; (i) editor, (ii) interpreter and (iii) simulator and provides nine full modules and also allows the users to configure/run/test their own circuits like real environment. The task of abstraction for modules through the actual circuit test was carried out on the basis of the data sheet and the specification provided by the manufacturer. If we can improve the level of quality of our solution, it can be useful in terms of cost reduction and easy learning. To achieve this end, the electrical physics engine, the level of interpreter that can be ported to the actual board, and a generalization of the simulation logic are required.

• Journal of Digital Contents Society
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• v.11 no.3
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• pp.323-330
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• 2010

Due to the widespread smartphones and application stores, mobile application developments are now booming again in the same manner of PC history. The smartphone software development process, however, gives much inconvenience to developers because of the heterogeneous platform APIs and hardware incompatibility between different devices. To make clear these problems, mobile web applications are being accepted as an alternative to the native smartphone applications. Mobile web applications can be developed more simply and easily than native applications by using webkit engine's html, Java script, and CSS. Additionally developers can provide a platform-independent applications since web applications are going to run on web browsers. In this paper, we develop a personal applications store running on an android phone's browsers. We can accomplish this very simply by using webkit's various APIs such as OpenID. We can find out by implementing a real web application that development of web applications can surpass the native one in cost and time period without much loss of performance.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1102-1109
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• 1993

This paper describes the research and development of Walking Tractors and Tillage Implements for Phase I (1991-1992) . The project consists of : (1) the study and need for the development of the walking tractors for Thailand and other Southeast Asian countries ; (2) the comparison in the use of the walking tractors and their transmission systems that are made in Thailand and aborad : and (3) the design of future walking tractors for Asian farmers in developing countries. The design of the walking tractors is concentrated to provide the ease to farmers, especially the elderly and female which will play an important role in the future agriculture of Thailand due to the lack of manpower. In addition , the design of the walking tractors is also aiming for small-scale farmers, the majority that have limited land capital. The walking tractors consist of several components but the most important one is the " Transmission System" . Thus, the research is concentrated in the devel pment an design of the a new transmission system. The new machine , currently developed, is named after the Chulalongkron University as " Chular Walking Tractor " , model SPJS -60. The tractor uses a 6-7 horsepower diesel engine with three forward gears and one reverse gear. The tractor also uses the latest gearing technology so called planetary gearing system with steering clutches system that never been used in any earlier model. The advantages of the planetary gearing system are : (1) the final drive gear can be small, and can be designed to provide higher strength with less wearing resistance, (2) the system eliminates a shaft which is used in other systems, thus reduces the weight and the manufacturing cost . Furthermore, the Chular Walking Tractor has an additional power take off shaft that can be used or linked with other standard agricultural implements.

• The Journal of the Acoustical Society of Korea
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• v.35 no.3
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• pp.183-191
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• 2016

A systematic development process for the low noise FEAD (Front End Accessory Drive) system is presented by combining CAE (Computer Aided Engineering) and the experimental rig test. In the estimation of the belt drive noise, two main difficulties arise from the high non-linearity due to the stick-slip contacts on the interfaces of the belt and pulleys, and the interaction of the belt drive system with the powertrain rotational parts. In this work, a recently developed analysis method of the belt drive has been employed considering powertrain rotational dynamics. As results, it shows good correlation with the vehicle tests in various operational modes. The established model has been employed to validate the new design improving the stick-slip noise of the problematic FEAD system. Furthermore, the best proposal of FEAD system in terms of functionality [NVH (Noise, Vibration and Harshness), fuel economy, cost. etc.] has been suggested in the concept design stage of new engine through this presented methodology.

• Journal of Powder Materials
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• v.10 no.6
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• pp.383-389
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• 2003

As in other areas of materials technology, the tendency towards light weight constructions becomes more and more important also for powder metallurgy. The development is mainly driven by the automotive industry looking for mass reduction of vehicles as a major factor for fuel economy. Powder metallurgy has to offer a number of interesting areas including the development of sintered materials of light metals. PM aluminium alloys with improved properties are on the way to replace ferrous pars. For high temperature applications in the engine, titanium aluminide based materials offer a great potential, e.g. for exhaust valves. The PM route using elemental powders and reactions sintering is considered to be a cost effective way for net shape parts production. Furthermore it is expected that lower costs for titanium raw materials coming from metallurgical activities will offer new chances for sintered parts with titanium alloys. The field of cellular metals expands with the hollow sphere technique, that can provide materials of many metals and alloys with a great flexibility in structure modifications. These structures are expected to be used in improving the safety (crash absoption) and noise reduction in cars in the near future and offer great potential for many other applications.

• Korean Journal of Construction Engineering and Management
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• v.23 no.4
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• pp.3-14
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• 2022

Autonomous equipment requires a large amount of data from various environments. However, it takes a lot of time and cost for an experiment in a real construction sites, which are difficulties in data collection and processing. Therefore, this study aims to develop a virtual environment for autonomous tower cranes technology development and validation. The authors defined automation functions and operation conditions of tower cranes with three performance criteria: operational design domain, object and event detection and response, and minimum functional conditions. Afterward, this study developed a virtual environment for learning and validation for autonomous functions such as recognition, decision making, and control using the Unity game engine. Validation was conducted by construction industry experts with a fidelity which is the representative matrix for virtual environment assessment. Through the virtual environment platform developed in this study, it will be possible to reduce the cost and time for data collection and technology development. Also, it is also expected to contribute to autonomous driving for not only tower cranes but also other construction equipment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.7
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• pp.2925-2930
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• 2011

A vehicle fuel economy is very important issue in the view of fuel cost and environmental regulation. The fuel economy is much improved according to the development of electric, electronic and mechanical technology, but up to now the measurement of it tests the given mode(LA-4, FTP-75, etc) within computer simulation program and engine dynamometer. This fuel economy is different with it of real road. The one of main reason is not considered the gradient of the road. To estimate the effects of fuel economy at highway with gradient in this paper, we measure the amount of fuel consumption and calculate the fuel economy of it with running the Youngdong highway with high gradient. Also this paper analysis and compares the fuel economy with gradient and without gradient when the vehicle runs the same driveway. Then we calculate the total energy created the difference of fuel consumption amount of the two cases and calculate the consumpted energy by tire driving force from the torque and power of engine in the simulation. This paper verifies the relation of the driving force and the total energy by creating the difference of fuel consumption amount. This paper also proposes the method of fuel economy improvement despite of gradient at the result.