• Progress in Superconductivity and Cryogenics
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• v.25 no.3
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• pp.13-17
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• 2023

Magnetic separation technology for small paramagnetic particles has been desired for the volume reduction of contaminated soil from the Fukushima nuclear power plant accident and for the separation of scale and crud from nuclear power plants. However, the magnetic separation for paramagnetic particles requires a superconducting high gradient magnetic separation system applied, hence expanding the bore diameter of the magnets is necessary for mass processing and the initial and running costs would be enormous. The use of high magnetic fields makes safe onsite operation difficult, and there is an industrial need to increase the magnetic separation efficiency for paramagnetic particles in as low a magnetic field as possible. Therefore, we have been developing a magnetic separation system combined with a selection tube, which can separate small paramagnetic particles in a low magnetic field. In the previous technique we developed, a certain range of particle size was classified, and the classified particles were captured by magnetic separation. In this new approach, the fluid control method has been improved in order to the selectively classify particles of various diameters by using a multi-stage selection tube. The soil classification using a multi-stage selection tube was studied by calculation and experiment, and good results were obtained. In this paper, we report the effectiveness of the multi-stage selection tube was examined.

• Journal of Chest Surgery
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• v.33 no.5
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• pp.385-390
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• 2000

Background: To review the experience that used both ventricular assist device(VAD) and extracorporeal membrane oxygenation(ECMO) for children with congential heart disease requiring postcardiotomy mechanical circulatory support. Material and Method: Between March 1993 and May 1995, we applied mechanical assist device using centrifugal pump to the 16 patients who failed to be weaned from cardiopulmonary bypass(n=15) or had been in cardiogenic shock in intensive care unit(n=1). The diagnosis were all congenital heart diseases and the ages of patients ranged from 20 days to 10 years (mean age=2.5$\pm$3.5 years). Result: The methods of mechanical circulatory support were LVAD(n=13), BVAD (n=1), and ECMO(n=2). The mean assist times were 54.0$\pm$23.7 hours. Post-assist complications were in orders: bleeding, acute renal failure, ventricular failure, respiratory failure, infection, and neurologic complication. It was possible for 9 patients(56.3%) to be weaned from assist device and 5 patients(31.3%) were discharged from hospital. There was no statistical significant between hospital discharged group and undischarged group by age, body weight, cardiopulmonary bypass time, and assist time. Conclusion: The ventricular assist device is an effective modality in salvaging the patient who failed to be weaned from cardiopulmonary bypass, but multiple factors must be considered for improving the results of mechanical circulatory support ; such as patient selection, optimal time of starting the assist device, and prevention and management of the complications.

• Korean Journal of Computational Design and Engineering
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• v.19 no.2
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• pp.191-201
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• 2014

A 3D CAD system that can be used on a smart device is proposed. Smart devices are now a part of everyday life and also are widely being used in various industry domains. The proposed 3D CAD system would allow modeling in a rapid and intuitive manner on a smart device when an engineer makes a 3D model of a product while moving in an engineering site. There are several obstacles to develop a 3D CAD system on a smart device such as low computing power and the small screen of smart devices, imprecise touch inputs, and transfer problems of created 3D models between PCs and smart devices. The author discusses the system design of a 3D CAD system on a smart device. The selection of the modeling operations, the assignment of touch gestures to these operations, and the construction of a geometric kernel for creating both meshes and a procedural CAD model are introduced. The proposed CAD system has been implemented for validation by user tests and to demonstrate case studies using test examples. Using the proposed system, it is possible to produce a 3D editable model swiftly and simply in a smart device environment to reduce design time of engineers.

• Industrial Engineering and Management Systems
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• v.3 no.2
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• pp.116-122
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• 2004

This paper presents a process plan selection model with multiple objectives. The process plans for all parts should be selected under multiple objective environment as follows: (1) minimizing the sum of machine processing and material handling time of all the parts considering realistic shop factors such as production volume, processing time, machine capacity, and capacity of transfer device. (2) balancing the load between machines. A multiple objective mathematical model is proposed and an evolutionary algorithm with the adaptive recombination strategy is developed to solve the model. To illustrate the efficiency of proposed approach, numerical examples are presented. The proposed approach is found to be effective in offering a set of satisfactory Pareto solutions within a satisfactory CPU time in a multiple objective environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.9
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• pp.1612-1616
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• 2006

For map services in the mobile environment, it should be considered that resource restriction or the mobile device. on, if a map database dedicated to mobile services may not be developed, the spatial data extracted from general map databases should be simplified before transmitting. % is paper suggests the filtering methods to manipulate the spatial data, which are changed to be able to displayed on the mobile devices. The suggested methods are evaluated by experiments. This method is based on the map generalization operator 'selection' and is refined to adapt on mobile phone environments.

• 전기의세계
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• v.25 no.4
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• pp.53-58
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• 1976

Criteria and significance of the factor .root..mu..$R_{u}$ or ($R_{u}$/.root.p) in Hall element material selection are discussed. And the chart which is useful to compare the figure of merit F=.root..mu..$R_{u}$ in Hall element materials is presented with the F's for some practical Hall device materials.als.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.6
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• pp.458-464
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• 1998

This paper gives characterization of substrate and PZT(53/47) thin film deposited by metalorganic decomposition, which is concerned in deposition process and device fabrication process, to fabricate micro electro mechanical system (MEMS) device with piezoelectric material. The PZT thin films deposited by MOD at 700^{\circ}C$ for 30 minutes had a polycrystallinity, that is, no substrate dependence, while different interface were developed depending on the bottom electrodes. Such a structural variation could influence on not only the properties of the PZT film but also etching process for fabricating MEMS devices. Therefore the electrode structure is a very important factor in the deposition of the PZT film during etching process by HF acid for MEMS device with piezoelectric material. Piezoelectric coefficients of the PZT films on the different substrates were 40 and 80 pm/V at an applied voltage of 4V. Based in these results, it was possible for deposition of the PZT film by MOD to apply MEMS device fabrication process based on piezoelectricity after selection of proper bottom electrode.

• Journal of Institute of Control, Robotics and Systems
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• v.11 no.5
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• pp.445-450
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• 2005

In this paper, we suggest an integrated tactile display system that provides kinesthetic force, pressure distribution, vibration and slip/stretch. The system consists of two parts: a 2 DOF force feedback device for kinesthetic display and a tactile feedback device for displaying the normal stimulation to the skin and the skin slip/stretch. Psychophysical experiments measure the effects of fingerpad selection, the direction of finger movements and the texture width on tactile sensitivity. We also investigate the characteristics of lateral finger movement while subjects perceive different textures. From the experimental results, the principal parameters for designing a tactile display are suggested. A tactile display device, using eight piezoelectric bimorphs and a linear actuator, Is implemented and attached to a 2 DOF translational force feedback device to simultaneously simulate the texture and stiffness of the object. As a result, we find out that the capability of the suggested device is sufficient to display physical quantities to display the texture.

• Journal of Information Processing Systems
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• v.13 no.2
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• pp.268-284
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• 2017

The dorsal hand vein biometric system developed has a main objective and specific targets; to get an electronic signature using a secure signature device. In this paper, we present our signature device with its different aims; respectively: The extraction of the dorsal veins from the images that were acquired through an infrared device. For each identification, we need the representation of the veins in the form of shape descriptors, which are invariant to translation, rotation and scaling; this extracted descriptor vector is the input of the matching step. The optimization decision system settings match the choice of threshold that allows accepting/rejecting a person, and selection of the most relevant descriptors, to minimize both FAR and FRR errors. The final decision for identification based descriptors selected by the PSO hybrid binary give a FAR =0% and FRR=0% as results.

• Journal of Korean Institute of Industrial Engineers
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• v.42 no.6
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• pp.395-403
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• 2016

In mobile industry, using a metal frame of devices is rapidly increased for thin and stylish designs. However, fabricating metal is one of the difficult processes because the sophisticated control of equipment is required during the whole machining time. In this study, we present an efficient multivariate monitoring procedure for the metal frame process in mobile device manufacturing. The effectiveness of the proposed procedure is demonstrated by real data from the mobile plant in one of the leading mobile companies in South Korea.