• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.11a
• /
• pp.320-321
• /
• 2006

In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indium-tin oxide (ITO) anodes using $CF_4g$ as and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $CF_4$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/$Alq_3$/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $CF_4$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The Impedance spectroscopy measurement of the devices with the $CF_4$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

• Journal of Industrial Technology
• /
• v.40 no.1
• /
• pp.19-23
• /
• 2020

In this paper, we proposed a PC-based CNC control system using EtherCAT-based servo drive and I/O device. The default communication of LinuxCNC is a parallel port, and data processing with high bandwidth is impossible. However, it is possible to apply various bandwidth devices through the application of EtherCAT, one of the industrial Ethernet communications with high bandwidth. Therefore, the hardware control method of LinuxCNC was applied through EtherCAT communication from the existing parallel port. Finally, through HAL configuration, I/O device operation check and 3-axis motion control proved the LinuxCNC system with EtherCAT.

• Journal of Power Electronics
• /
• v.16 no.5
• /
• pp.1894-1903
• /
• 2016

In general, electrolytic capacitors are used to reduce power pulsations on PV-panels. However, this can reduce the reliability of the PV AC-module system, because electrolytic capacitors have a shorter lifetime than PV-panels. In addition, PV-panels generate irregular power and inject it into the grid because the output power of a PV-panel depends on the surrounding conditions such as irradiation and temperature. To solve these problems, a grid-connected photovoltaic (PV) AC-module with active power decoupling and energy storage is proposed. A parallel bi-directional converter is connected to the AC module to reduce the output power pulsations of PV-panels. Thus, the electrolytic capacitor can be replaced with a film capacitor. In addition, the irregular output power due to the surrounding conditions can be regulated by using a parallel energy storage circuit. To maintain the discontinuous conduction mode at low irradiation, the frequency control method is adopted. The design method of the proposed converter and the operation principles are introduced. An experimental prototype rated at 125W was built to verify the performance of the proposed converter.

• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.119-120
• /
• 2006

The impedance spectroscopy is one of the effective ways to understand the electrical properties of organic light emitting diodes. The frequency-dependant properties of small molecule based OLEDs have been studied. The equivalent circuit of single-layer device is composed of contact resistance ($R_c$), bulk resistance ($R_p$) and bulk capacitance ($C_p$). The equivalent circuit of double layer device is composed of two parallel circuits connected in series, each of which is a parallel resistor and a capacitor. We have fabricated a double layer device indium-rio-oxide (ITO, anode), N,NV -diphenyl- N,NV -bis(3-methylphenyI)-1,1V -diphenyl-4,4V-diamine (TPD, hole-transporting layer), tris-(8-hydroxyquinoline) aluminum (Alq3, emitting layer), and aluminum (AI, cathode) and two single layer devices ([TO/ Alq3/ AI, ITO/TPD/AI).

• The Journal of the Korea institute of electronic communication sciences
• /
• v.7 no.6
• /
• pp.1493-1498
• /
• 2012

RFID technology plays an important role in building a ubiquitous environment. As RFID tags are widely used, it is necessary to enhance the performance of massive tag writes. A tag write tends to fail since it is performed through the weak radio wave communication. In this paper, we propose a write scheme that to enhance the performance of massive RFID tag writes. In proposed scheme, tag writes performed in parallel by multiple readers connected to a middleware. Write operations are distributed among readers and tags are written in groups. We show that proposed scheme can increase the success ratio of massive tag writes through experimental tests.

• The KIPS Transactions:PartA
• /
• v.9A no.4
• /
• pp.511-518
• /
• 2002

Symmetric Multiprocessors (SMP) has emerged as an important and cost-effective platform for high performance parallel computing. Scheduling of parallel tasks and communications of SMP is important because the choice of a scheduling discipline can have a significant impact on the performance of the system. In this paper, we present a task duplication based scheduling scheme for bus-based SMP. The proposed scheme pre-allocates network communication resources so as to avoid potential communication conflicts. The performance of the proposed scheme has been observed by comparing the schedule length under various number of processors and the communication cost.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2006.06a
• /
• pp.436-437
• /
• 2006

In this work, impedance Spectroscopic analysis was applied to study the effect of plasma treatment on the surface of indum-tin oxide (ITO) anodes using $O_2$ gas and to model the equivalent circuit for organic light emitting diodes (OLEDs) with the $O_2$ plasma treatment of ITO surface at the anodes. This device with ITO/TPD/Alq3/LiF/Al structure can be modeled as a simple combination of a resistor and a capacitor. The $O_2$ plasma treatment on the surface of ITO shifts the vacuum level of the ITO as a result of which the barrier height for hole injection at the ITO/organic interface is reduced. The impedance spectroscopy measurement of the devices with the $O_2$ plasma treatment on the surface of ITO anodes shows change of values in parallel resistance ($R_p$) and parallel capacitance ($C_p$).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.17 no.3
• /
• pp.999-1021
• /
• 2023

Differential spatial modulation uses the antenna index to transmit information, which improves the spectral efficiency, and completely bypasses any channel side information in the recommended setting. A generalized distributed multiple turbo coded-cooperative differential spatial modulation based on distributed multiple turbo code is put forward and its performances in Rayleigh fading channels is analyzed. The generalized distributed multiple turbo coded-cooperative differential spatial modulation scheme is a coded-cooperation communication scheme, in which we proposed a new joint parallel iterative decoding method. Moreover, the code matched interleaver is considered to be the best choice for the generalized multiple turbo coded-cooperative differential spatial modulation schemes, which is the key factor of turbo code. Monte Carlo simulated results show that the proposed cooperative differential spatial modulation scheme is better than the corresponding non-cooperative scheme over Rayleigh fading channels in multiple input and output communication system under the same conditions. In addition, the simulation results show that the code matched interleaver scheme gets a better diversity gain as compared to the random interleaver.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.4
• /
• pp.409-416
• /
• 2014

In H/W implementation for the finite field, the use of normal basis has several advantages, especially the optimal normal basis is the most efficient to H/W implementation in $GF(2^m)$. The finite field $GF(2^m)$ with type I optimal normal basis(ONB) has the disadvantage not applicable to some cryptography since m is even. The finite field $GF(2^m)$ with type II ONB, however, such as $GF(2^{233})$ are applicable to ECDSA recommended by NIST. In this paper, we propose a bit-parallel multiplier over $GF(2^m)$ having a type II ONB, which performs multiplication over $GF(2^m)$ in the extension field $GF(2^{2m})$. The time and area complexity of the proposed multiplier is the same as or partially better than the best known type II ONB bit-parallel multiplier.

• The Journal of the Korea Contents Association
• /
• v.5 no.1
• /
• pp.179-187
• /
• 2005

Linear order Concentrators and Superconcentrators have been studied extensively for their ability to interconnect large numbers of devices in parallel, whether in communication systems or in parallel computers. One major limitation on the efficiency of parallel computer designs has been the prohibitively high cost of parallel communication between processors and memories. Linear order concentrators, O(n), can be used to construct theoretically optimal interconnection network schemes. Existing explicitly the defined constructions are based on expanders, which have large constant factors, thereby rendering them impractical lot reasonable sized networks. It demands the construction of concentrator which uses the expander with the smaller expansion constant. This paper introduces an improvement on the method of constructing concentrators using expanders, which reduce the size of resulting concentrator built from any given expander by a constant factor.