• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.408-413
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• 2013

Micro-features such as grooves and lenses, which perform optical functions in flat displays, should be manufactured with a good form accuracy because this is directly related to their optical performance. As the size of the display increases, it is very difficult to maintain a high relative accuracy because of the inherent geometric errors such as the waviness of a large-area plate. In this paper, the optical effect of these geometric errors is investigated, and surface-referenced micro-grooving to measure and compensate for such geometric errors on line is proposed to improve the form accuracy of the micro-grooves. A PZT-based fast depth adjustment servo system is implemented in the tool holder to maintain a uniform groove depth in reference to the wavy surface. Through experiments, the proposed method is shown to be an efficient way to produce high-quality micro- grooves on a wavy die surface.

• The Journal of Industrial Distribution & Business
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• v.14 no.12
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• pp.1-9
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• 2023

Purpose: As China's economic development enters new normal, employee happiness degree of small and micro enterprises will take on new features. The purpose of this paper is to discover the characteristics of changes in employee happiness, and provide reference and management suggestions. Research design, data and methodology: This paper determined the factors affecting employee happiness, established a measure model of happiness, measured and analyzed employee happiness by selecting more than 1,108 employees from 30 domestic small and micro enterprises. Results: First, the overall level of happiness in small and micro enterprises is relatively low. Second, there is no significant difference in happiness perception among employees in terms of the six factors. Third, the employees of small and micro enterprises have the highest happiness in three issues, including work distribution, internal interpersonal relationships, and less institutional constraints, the happiness on the two compensation benefits and a democratic management issue is the lowest. Fourth, gender factor has no significant effect on employee happiness, while age, working years, education, position, and the nature of employment have a significant impact on happiness. Conclusions: Employee happiness of small and micro enterprises will take on new features. Some human resource management suggestions are proposed from different perspectives based on the survey results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.12
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• pp.1173-1179
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• 2007

In recent years, research to machine large-surface micro-features has become important because of the light guide panel of a large-scale liquid crystal display and the bipolar plate of a high-capacity proton exchange membrane fuel cell. In this study, in order to realize the systematic design technology and performance improvements of an ultra-precision machine for machining the large-surface micro-features, a structural characteristic analysis was performed using its virtual prototype. The prototype consisted of gantry-type frame, hydrostatic feed mechanisms, linear motors, brushless DC servo motor, counterbalance mechanism, and so on. The loop stiffness was estimated from the relative displacement between the tool post and C-axis table, which was caused by a cutting force. Especially, the causes of structural stiffness deterioration were identified through the structural deformation analysis of sub-models.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1124-1128
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• 2008

Thin-wall injection molding is associated with many advantages, including increased portability, the conserving of materials, and the reduction of the molding cycle times. In the application of the thin-wall molding, a considerable reduction of the effective flow thickness results in filling difficulty. High-frequency induction is an efficient way to overcome this filling difficulty by means of heating the mold surface by electromagnetic induction. The present study applies the induction heating to the injection molding of thinwalled micro structures with high aspect ratio. The feasibility of the proposed heating method is investigated through a numerical analysis. The estimated filling characteristics of the micro-features are investigated with variations of mold temperature and part thickness, of which results are also compared with experimental measurements.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.45-46
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• 2006

In recent years, micro powder injection molding $(\mu-PIM)$ is being explored as an economical fabrication method for microcomponents in microsystems technology (MST). Technical and economic comparison was performed for $\mu-PIM$ processes. Molding experiment and simulation during the filling process were performed to evaluate several different geometries and processing conditions. The influence of material parameters and process conditions on mold filling were examined as a function of features size using microchannels as an example. It was found that the heat conductivity and viscosity of feedstock, geometry and mold temperature were the most critical parameters for complete filling of micro features.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.1 s.190
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• pp.47-56
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• 2007

Recently, demands on mechanical micro machining technology have been increased in manufacturing of micro-scale precision shapes and parts. The main purpose of this research is to verify the accuracy and cost efficiency of the mechanical micro machining. In order to measure the precision and feasibility of mechanical micro machining, various micro features were machined. Aluminum molds were machined by a 3-axis micro stage in order to fabricate microchips with $200{\mu}m$ wide channel for capillary electrophoresis, then the same geometry of microchip was made by injection molding. To evaluate the cost efficiency of various micro manufacturing processes, cost estimation for mechanical micro machining was conducted, and actual costs of microchips fabricated by mechanical micro machining, injection molding, and MEMS (Micro electro mechanical system) were compared.

• Journal of Korea Society of Digital Industry and Information Management
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• v.8 no.1
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• pp.9-15
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• 2012

Multiple convenience features have been getting installed in recently released cars. However, the control of them has many uncomfortable matters yet. To resolve them, it is needed to study how to use easier the convenience features and control them remotely. Currently, wide range of convergence services are being released in various industries by using smartphone and smartphones with its state-of-the-art functions also are being released. In this paper, we design and implement smartphone-based applications for controling the vehicle's convenience features to control the vehicle convenience features with smartphone. To do this, we configure CAN (Controller Area Network) communication between the vehicle's various convenience features, and establish MCU (Micro Controller Unit) to control each feature. We also connect between the MCU and smartphones to make them available for the remote control. We can control lights, turn signals, audio, windows, air conditioner, and so on with the implemented smartphone-based control service of vehicle's convenience features using CAN remotely.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.627-628
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• 2010

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3005-3027
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• 2015

Spam has become one of the top threats of micro-blogging networks as the representations of rumor spreading, advertisement abusing and malware distribution. With the increasing popularity of micro-blogging, the problems will exacerbate. Prior detection tools are either designed for specific types of spams or not robust enough. Spammers may escape easily from being detected by adjusting their behaviors. In this paper, we present a novel model to quantitatively evaluate information diffusion in micro-blogging networks. Under this model, we found that spam posts differ wildly from the non-spam ones. First, the propagations of non-spam posts mostly result from their followers, but those of spam posts are mainly from strangers. Second, the non-spam posts relatively last longer than the spam posts. Besides, the non-spam posts always get their first reposts/comments much sooner than the spam posts. With the features defined in our model, we propose an RBF-based approach to detect spams. Different from the previous works, in which the features are extracted from individual profiles or contents, the diffusion features are not determined by any single user but the crowd. Thus, our method is more robust because any single user's behavior changes will not affect the effectiveness. Besides, although the spams vary in types and forms, they're propagated in the same way, so our method is effective for all types of spams. With the real data crawled from the leading micro-blogging services of China, we are able to evaluate the effectiveness of our model. The experiment results show that our model can achieve high accuracy both in precision and recall.

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.158-163
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• 2001

Operators suffer much difficulty in manipulating micro/nano-sized objects without the assistance of human interfaces, due to the scaling effects in micro/nano world. This paper presents a micro manipulation system based on the teleoperation techniques which enables the operators to manipulate the objects with ease by transferring both human motion and manipulation skill to a micromanipulator. An experimental setup consisting of a micromanipulator operated under stereo-microscope with the help of intelligent user interface provides a tool that can be used to visualize and manipulate micro-sized 3D objects in a controlled manner. The key features of a micro manipulation system and control strategies using teleoperation techniques for handling micro objects are presented. Experimental results demonstrate the feasibility of this system in precisely controlling trapping and manipulation of micro objects based on teleoperation techniques.