• Journal of Power Electronics
• /
• v.2 no.4
• /
• pp.250-257
• /
• 2002

This paper introduces the Interactive Power Electronics Seminar - iPES - a new software package for teaching of fundamentals of power electronic circuits and systems. iPES is constituted by HTML text with Java applets for interactive animation, circuit design and simulation and visualization of electromagnetic fields and thermal issues in power electronics. It does comprise an easy-to-use self-explaining graphical user interface. The software does need just a standard web-browser, i.e. no installations are required. iPES can be accessed via the World Wide Web or from a CD-ROM in a stand-alone PC by students and professionals. Due to the underlying software technology iPES is very flexible and could be used for on-line learning and could easily be integrated into an e-learning platform. The aim of this paper Is to give an introduction to the iPES-project and to show the different areas covered. The e- learning software is available at no costs at $\underline{www.ipes.ethz.ch}$ in English, German, Japanese, Korean, Chinese and Spanish. The project is still under development and the web page is updated in about 4 weeks intervals.

• Membrane Journal
• /
• v.17 no.3
• /
• pp.219-232
• /
• 2007

The polyethersulfone(PES)-titanium oxide($TiO_2$) hybrid membranes were prepared by immersion precipitation phase inversion method. The casting solution for the preparation of $PES-TiO_2$ hybrid membrane was provided by adding $TiO_2$ nano particles into the basis polymer solution of 14 wt% and 20 wt% PES/N-methyl-2-pyrrolidone(NMP). The $TiO_2$ loading [wt% ($TiO_2/NMP$)] in eating solution was varied from 0 to 60 wt%. Membrane performance and morphological change of the resulting $PES-TiO_2$ hybrid membranes were discussed in aspect of $TiO_2$ loading, by viscosity, coagulation value and light transmittance of the casting solution, measurement of tensile strength, pore size and contact angle, surface and cross sectional SEM images of the hybrid membrane, and ultrafiltration experiments using the hybrid membrane. According as increase of $TiO_2$ loading in the casting solution, viscosity is increased and coagulation value becomes lower, therefore the thermodynamic instability of the casting solution is increased. It is found that when $TiO_2$ loading is increased, 1) precipitation rate becomes faster while instantaneous demixing is maintained, 2) pure water flux, membrane pore size and compaction stability of the resulting membranes are increased, 3) tensile strength and contact angle are decreased. Dead-end ultrafiltration of bovine serum albumin(BSA) solution using the hybrid membrane shows that membrane performance(flux of BSA solution) enhanced up to 7 times compared with the results obtained using the pure PES membrane(not containing $TiO_2$ particle), due to the increase of hydrophilicity.

• Journal of Advanced Marine Engineering and Technology
• /
• v.40 no.4
• /
• pp.353-361
• /
• 2016

This work presents an investigation of the radio frequency characteristics of an FTLPGS (fishbone-type transmission line employing periodic ground structure) fabricated on PES (polyether sulfone) for the realization of a transparent flexible wireless communication device. According to the results, the FTLPGS on PES showed a shorter wavelength characteristic when compared with a conventional coplanar waveguide. Concretely, the wavelength of the FTLPGS was 1.91 mm at 50 GHz, which was 48.5% of the conventional coplanar waveguide. The bandwidth extraction result showed that the passband of the FTLPGS on PES was 250 GHz. Unlike conventional periodic structures, the characteristic impedance of the FTLPGS on PES also showed a very low frequency dependency. A miniaturization of the RF circuit on the PES substrate was made possible by the FTLPGS on PES having shown characteristic impedance lower than that of conventional transmission lines. These results mean that, with a broadband operation frequency, the FTLPGS on PES is a suitable construction application for the transmission line and distributed passive components.

• The Journal of Korean Orthopaedic Ultrasound Society
• /
• v.2 no.1
• /
• pp.13-17
• /
• 2009

Purpose: The purpose of this study was to know the cause of the tenderness at pes anserinus. Materials and Methods: Out of 24 patients with tenderness at pes anserinus, 23 patients were female and 1 patient was male, and their average age was 65.9 years old. We checked the tenderness at pes anserinus by history taking & physical examniation and then, checked the pes anserinus for the presence of bursitis by US in outpatient clinic. With no evidence of bursitis by US, we injected steroid-lidocaine mixture intraarticularly and checked whether the tenderness disappeared after 2~3 minutes. Results: There was no case with bursitis at pes anserinus by US. The tenderness at pes anserinus diminished in 2-3 minutes after the intraarticular injection of the steroid-lidocaine mixture. After 6 weeks follow up, 16 patients(66.7%) had little or no tenderness at pes anserinus. 8 cases had the recurrence of tenderness recurred, 4 cases underwent arthroscopic operation on the meniscal tear, and 1 case underwent total knee arthroplasty. All cases underwent any operations had the tenderness at pes anserinus disappeared. The others 3 cases did not undergo total knee arthroplasty despite of radiologic obliteration of knee joint adequate for Kellgren-Lawrence grade IV. Conclusion: Without the bursitis at Pes Anserinus, patients the osteoarthritis may have the tenderness due to the referred pain.

• Journal of the Microelectronics and Packaging Society
• /
• v.14 no.1
• /
• pp.27-31
• /
• 2007

The cpapcitors with MIM(metal-insulator-metal) structures using PVP gate insulation films were prepared for the application of flexible organic thin film transistors (OTFT). The co-polymer organic insulation films were synthesized by using PVP(poly-4-vinylphenol) as a solute and PGMEA(propylene glycol monomethyl ether acetate) as a solvent. The cross-linked PVP insulation films were also prepared by addition of poly(melamine-co-formaldehyde) as thermal hardener. The leakage current of the cross- linked PVP films was found to be about 1.3 nA on Al/PES(polyethersulfone) substrate, whereas, on ITO/ glass substrate was about 27.5 nA indicating improvement of the leakage current at Al/PES substrates. Also, the capacitances of all prepared samples on ITO/glass and Al/PES substrates w ere ranged from 1.0 to $1.2nF/cm^2$, showing very similar result with the calculated capacitance values.

• Journal of the Korean Society of Industry Convergence
• /
• v.4 no.1
• /
• pp.77-85
• /
• 2001

This paper was to investigate the preparation of polysulfone(PS), polyethersulfone(PES) and polyphenylsulfone(PPS) membrane. The thermal property of PPS was higher than that of others. From the result of SEM, the concentration of polymer was found to have a significant effect on the structure of membrane, and the structure of membrane made of PES is found to have regular micell form of asymmetry. Permeability and selectivity for oxygen and nitrogen gas in the air were analyzed by GC. Permeabilities of the membrane made of PES for oxygen and nitrogen in air, 1.5 and $0.7(x10^9[cm^3(STP)cm/cm^2seccmHg]) $, respectively was higher than that of others. and Selectivity of the membrane made of PPS for oxygen to nitrogen gas in air was 2.9.

• ETRI Journal
• /
• v.37 no.1
• /
• pp.128-137
• /
• 2015

In this work, a fishbone-type transmission line employing a comb-type ground plane (FTLCGP) was fabricated on polyethersulfone (PES) substrate, and its RF characteristics were thoroughly investigated. According to the results, it was found that the FTLCGP on PES showed periodic capacitance values much higher than other types of transmission lines due to a coupling capacitance between the signal line and ground, which resulted in a reduction of wavelength and line width. Using the theoretical analysis, we also extracted the bandwidth characteristic of the FTLCGP on PES. According to the result, the FTLCGP structure showed a cut-off frequency of 280 GHz.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.24 no.3
• /
• pp.49-62
• /
• 1999

Artificial Neural Networks(ANN) have been successfully applied to various kinds of business and engineering problems, especially those involved in pattern classification. However, because of the lack of design standard or guidelines, the structure of specific ANN depends on the designer's own experiments or choices. In other words, even though we could construct a better ANN, we often steeled down with just a satisfactory ANN. The purpose of this research is to apply the Genetic Algorithm(GA) to design a structure of ANN that yields better performance compared to the existing test results. For a bankruptcy prediction problem. an exiting research using ANN which consists of 22 input processing elements(PEs) for financial ratios and 5 hidden PEs showed 70% hit ratio. In our research, the input financial ratios and the number of hidden PEs are determined by GA. The best ANN, which consists of 8 input PEs and 6 hidden PEs, shows 78.03% hit ratio. In addition, we compare the performance of two types of reproduction schemes, i.e., generational reproduction and steady-state reproduction.

• Journal of the Korean Ceramic Society
• /
• v.43 no.3 s.286
• /
• pp.185-192
• /
• 2006

The effects of annealing on structural and electrical properties of ITO/PES (Indium Tin Oxide/Polyethersulfone) films was investigated. Amorphous ITO thin films were grown on plastic substrates, PES using low temperature DC magnetron sputtering. Various post annealing techniques were attempted to research variations of microstructure and electrical properties: i) conventional thermal annealing, ii) excimer laser annealing, iii) UV irradiation. The electrical properties were obtained using Hall effect measurements and DC 4-point resistance measurement. The microstructural features were characterized by FESEM, XRD, Raman spectroscopy in terms of morphology and crystallinity. Optimized UV treatment exhibits the enhanced conductivity and crystallinity, compared to those of conventional thermal annealing.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2001.11a
• /
• pp.58-64
• /
• 2001

An investigation of the TMR(Track Misregistration) requirements to achieve the capacity of 80GBytes／Platter in 7200rpm disk drive system is reported. This paper also gives an overview of the PES(Position Error Signal) characteristics in the 57,500TPI disk drive to estimate the required 95,000TPI-system PES. The TMR measured by PES are presented and decomposed in order to identify the portions and their contributions of the spindle-disk system vibration and HSA(Head-Stack-Assembly) system vibration respectively. A comprehensive review on the servo system is also presented to provide the practical limits of the modem servo architecture into TMR budget design. The decomposed PES energy distribution shows that the spindle-disk pack vibration is one of the top-ranking sources of the total TMR budget and its percentage contribution is about 50％ considering all the other TMR sources.