• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1657-1662
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• 2017

Facial expression recognition systems using video devices have emerged as an important component of natural human-machine interfaces which contribute to various practical applications such as security systems, behavioral science and clinical practices. In this work, we present a new method to analyze, represent and recognize human facial expressions using a sequence of facial images. Under our proposed facial expression recognition framework, the overall procedure includes: accurate face detection to remove background and noise effects from the raw image sequences and align each image using vertex mask generation. Furthermore, these features are reduced by principal component analysis. Finally, these augmented features are trained and tested using Hidden Markov Model (HMM). The experimental evaluation demonstrated the proposed approach over two public datasets such as Cohn-Kanade and AT&T datasets of facial expression videos that achieved expression recognition results as 96.75% and 96.92%. Besides, the recognition results show the superiority of the proposed approach over the state of the art methods.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1324-1326
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• 1998

To drive motor or heating machine, it needs the electric power system like the apparatus of inverter. This electric power system obviously comprises power switching devices and drivers to run them. And this system has the topology comprised one/many arm(s), - each arm has high side switching device and low side switching device. Transformer, photocoupler, and HVIC having functions of isolation and level shift which are important thing to drive high side switching device are used as component of drivers in conventional apparatus. Piezoelectric transformers are proposed in this paper, and applied to drive high side swiching device. Through experiments, the possiblities of driving high side switching device are presented and the problems are mooted concurrently. But, we also consider a counterplan for solving the mooted trouble issues.

• Proceedings of the KIEE Conference
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• 1993.11a
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• pp.139-141
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• 1993

A new scheme to measure the rotor time constant and to set the slip gain of a vector-controller is presented. The approach utilizes the phase difference between the torque producing component of the stator current and rotor current in the stationary frame. It is shown that the rotor time constant can be uniquely identified by detecting the corresponding phase difference. The simulation was carried out by considering the variation of other parameters and the torque producing component of the stator current frequency.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.2
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• pp.295-300
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• 2010

Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions arc tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.8 no.4
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• pp.48-53
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• 2009

Inconel 718 alloy, widely used as material of aircraft engine, has a good mechanical property in high temperature, strong anti-oxidation characteristics in oxidated current over $900^{\circ}C$, and also is not easily digested in the air containing sulfur, therefore, its usage as mechanical component is expanding rapidly. Even though Inconel alloy 718 is difficult to machine, it requires highly precise processing/machining to sustain its component quality of high accuracy. In this paper, general turning operation conditions are tested to select the best cutting process condition by measuring surface roughness through implementing experiments with orthogonal array of cutting speed, feeding speed and cutting depth as processing parameters based on the Taguchi method. Optimal turning operation conditions are extracted from the proposed experimental models.

• Journal of the Korean Society for Precision Engineering
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• v.8 no.3
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• pp.73-81
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• 1991

There have been many studies on chatter vibration in machining but there seems to be no regulations to decide the commencing point of chatter objectively. The development of an objective method which can estimate and detect chatter commencement is very much in need for automatic manufacturing systems, dynamic performance tests for machine tools, so on. In this study, therefore, the estimation and the in-process detection of chatter have been experi- mentally investigated for the turning process. As a result, the commencing point of chatter can be decided from the behavior of the maximum amplitude of the dynamic component of cutting force, where the maximum amplitude is suddenly increasing with the chatter commencement. Then the commencing point of chatter can be estimated practically by this method before the occurrence of excessive vibration. Also, it is possible to detect the occurence of chatter vibration through the in-process measurement, by monitoring the maximum amplitude of the dynamic component of cutting force.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.05a
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• pp.163-168
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• 2002

Hot forging is widely used in the manufacturing of industry machine component. The mechanical, thermal load and thermal softening which are happened by the high temperature in hot forging process. Tool life decreases considerably due to the softening of the surface layer of a tool caused by a high thermal load and long contact time between the tool and billet. Also, tool life is to a large extent limited by wear, heat crack and plastic deformation in hot forging process. These are one of the main factors affecting die accuracy and tool life. That is because hot forging process has many factors influencing tool life, and there was not accurate in-process data. In this research, life prediction of hot forging tool by wear and plastic deformation analysis considering tempering parameter has been carried out for automobile component. The new developed technique in this study for predicting tool life can give more feasible means to improve the tool life in hot forging process.

• Journal of the Korea Society of Computer and Information
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• v.20 no.12
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• pp.21-28
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• 2015

In this paper, we propose a method of glasses detection in facial image. we develop a detection method of glasses with a weighted sum of the results that detected by facial element detection and glasses frame candidate region. Component of the face detection method detects the glasses, by defining the detection probability of the glasses according to the detection of a face component. Method using the candidate region of the glasses frame detects the glasses, by defining feature of the glasses frame in the candidate region. finally, The results of the combined weight of both methods are obtained. The proposed method in this paper is expected to increase security system's recognition on facial accessories by raising detection performance of glasses or sunglasses for using ATM.

• Transactions of Materials Processing
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• v.20 no.4
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• pp.279-283
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• 2011

Recently incremental sheet metal forming (ISF) has used widely in making prototypes and small-volume products in automotive industry etc. We apply the ISF to make a 1/4 sized automobile body-in-white. First, ISF tests for rectangular shaped cup have been performed to clarify the formability denoting the relationship between the component wall angle and maximum cup height of safe forming. Next, a CAD model for the automobile was designed and segmented into several components in order to accommodate the working space of the CNC machine we adopted and the formability of the sheet metal. Then, a CAM software was employed to generate the tool path for manufacturing wooden dies and all the small parts. Finally, the different parts were joined into a single component by laser welding after the ISF process. By using the ISF we successfully produced the 1/4 sized automobile body-in-white.

• Transactions of the Korean Society of Mechanical Engineers
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• v.17 no.12
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• pp.2949-2961
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• 1993

Dynamic cutting process can be represented by a closed-loop0 system consisted of machine tool structure and pure cutting process. On this paper, cutting system is modeled as a six degrees of freedom system using MARV(Modified Autoregressive Vector) model in face milling, and the modeled dynamic cutting process is used to predict dynamic cutting force component. Based on the double modulation principle, a dynamic cutting force model is developed. From the simulated relative displacements between tool and workpiece the dynamic force domponents can be calculated, and the dynamic force can be obtained by superposition of the static force and dynamic force components. The simulated dynamic cutting forces have a good agreement with the measured cutting force.