• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.233-236
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• 2012

In this paper, the output characteristics of GaN-based LED considering blocking layer design variables are analyzed. The basic structure of the LED consists of active region of GaN barrier and InGaN quantum well between AlGaN EBL(Electron Blocking Layer) and AlGaN HBL(Hole Blocking Layer) on GaN buffer layer. The output power, internal quantum efficiency characteristics of LED active region considering Al mole fraction of EBL, thickness of EBL, Al mole fraction of HBL and doping concentration of HBL are analyzed using ISE-TCAD.

• Journal of IKEEE
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• v.27 no.1
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• pp.12-18
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• 2023

The current circuit technology that individually connects each qubit to a control circuit at room temperature has limitations in achieving scalability and reliability of a quantum computer. With the advent of cryogenic CMOS interconnect electronics, it is expected to dramatically improve the interconnect complexity, system reliability and size, and price. In this paper, we introduce the CMOS integrated sensing and control technology platform overcoming the problems caused by the fragile and sensitive characteristics of qubit.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.11
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• pp.1-8
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• 1990

We made a 12-Laser Diode Array consisting of 12 Graded Index Separate Confinement (GRINSCH) InGaAs/Inp Buried Heterostructure 4 Quantum Well Laser Diodes and examined the potential of controlling lasing operation of each laser diode by the voltage to its electroabsorption region. Using Si V-Groove with 12 V-grooves, a 12-Laser Diode Array, and 12 optical fibers, we investigated the various characteristics of each laser diode by changing the voltage to its electro-absorption region. Finally, we thought over the promising way of implementing optical local area communication between electric circuit boards or between subscribers and a central office using a 12-Laser Diode Array, Si V-groove, and optical fibers.

• International Journal of Internet, Broadcasting and Communication
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• v.14 no.3
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• pp.1-7
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• 2022

This paper aims to compare the mean object size of M/G/1/PS model with that of M/BP/1 model used in the web service. The mean object size is one of important measure to control and manage web service economically. M/G/1/PS model utilizes the processor sharing in which CPU rotates in round-robin order giving time quantum to multiple tasks. M/BP/1 model uses the Bounded Pareto distribution to describe the web service according to file size. We may infer that the mean waiting latencies of M/G/1/PS and M/BP/1 model are equal to the mean waiting latency of the deterministic model using the round robin scheduling with the time quantum. Based on the inference, we can find the mean object size of M/G/1/PS model and M/BP/1 model, respectively. Numerical experiments show that when the system load is smaller than the medium, the mean object sizes of the M/G/1/PS model and the M/BP/1 model become the same. In particular, when the shaping parameter is 1.5 and the lower and upper bound of the file size is small in the M/BP/1 model, the mean object sizes of M/G/1/PS model and M/BP/1 model are the same. These results confirm that it is beneficial to use a small file size in a web service.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.17 no.1
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• pp.74-96
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• 2023

At present, the smart grid has become one of the indispensable infrastructures in people's lives. As a commonly used communication method, wireless communication is gradually, being widely used in smart grid systems due to its convenient deployment and wide range of serious challenges to security. For the insecurity of the schemes based on large integer factorization and discrete logarithm problem in the quantum environment, an identity-based key management scheme for smart grid over lattice is proposed. To assure the communication security, through constructing intra-cluster and inter-cluster multi-hop routing secure mechanism. The time parameter and identity information are introduced in the relying phase. Through using the symmetric cryptography algorithm to encrypt improve communication efficiency. Through output the authentication information with probability, the protocol makes the private key of the certification body no relation with the distribution of authentication information. Theoretic studies and figures show that the efficiency of keys can be authenticated, so the number of attacks, including masquerade, reply and message manipulation attacks can be resisted. The new scheme can not only increase the security, but also decrease the communication energy consumption.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.1343-1346
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• 2005

Self assembled monolayers (SAM) are generally used at the anode/organic interface to enhance the carrier injection in organic light emitting devices, which improves the electroluminescence performance of organic devices. This paper reports the use of SAM of 1-decanethiol (H-S(CH2)9CH3) at the cathode/organic interface to enhance the electron injection process for organic light emitting devices. Aluminum (Al), tris-(8-hydroxyquionoline) aluminum (Alq3), N,N'-diphenyl-N,N'-bis(3 -methylphenyl)-1,1'- diphenyl-4,4'-diamine (TPD) and indium-tin-oxide (ITO) were used as bottom cathode, an emitting layer (EML), a hole-transporting layer (HTL) and a top anode, respectively. The results of the capacitancevoltage (C-V), current density -voltage (J-V) and brightness-voltage (B-V), luminance and quantum efficiency measurements show a considerable improvement of the device performance. The dipole moment associated with the SAM layer decreases the electron schottky barrier between the Al and the organic interface, which enhances the electron injection into the organic layer from Al cathode and a considerable improvement of the device performance is observed. The turn-on voltage of the fabricated device with SAM layer was reduced by 6V, the brightness of the device was increased by 5 times and the external quantum efficiency is increased by 0.051%.

• ETRI Journal
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• v.44 no.3
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• pp.504-511
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• 2022

Monte Carlo simulations show that, as temperature increases, the average kinetic energy of channel electrons in a GaN transistor first decreases and then increases. According to the calculations, the relative energy change reaches 40%. This change leads to a reduced barrier height due to quantum coupling among the three-dimensional motions of channel electrons. Thus, an analysis and physical model of the gate leakage current that includes drift velocity is proposed. Numerical calculations show that the negative and positive temperature dependence of gate leakage currents decreases across the barrier as the field increases. They also demonstrate that source-drain voltage can have an effect of 1 to 2 orders of magnitude on the gate leakage current. The proposed model agrees well with the experimental results.

• ETRI Journal
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• v.45 no.3
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• pp.534-542
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• 2023

The large amount of secondary effects in complementary metal-oxide-semiconductor technology limits its application in the ultra-nanoscale region. Circuit designers explore a new technology for the ultra-nanoscale region, which is the quantum-dot cellular automata (QCA). Low-energy dissipation, high speed, and area efficiency are the key features of the QCA technology. This research proposes a novel, low-complexity, QCA-based one-bit digital comparator circuit for the ultra-nanoscale region. The performance of the proposed comparator circuit is presented in detail in this paper and compared with that of existing designs. The proposed QCA structure for the comparator circuit only consists of 19 QCA cells with two clock phases. QCA Designer-E and QCA Pro tools are applied to estimate the total energy dissipation. The proposed comparator saves 24.00% QCA cells, 25.00% cell area, 37.50% layout cost, and 78.11% energy dissipation compared with the best reported similar design.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.10
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• pp.3256-3274
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• 2022

With the rapid development of information and communications technology, the construction of efficient, reliable, and safe Internet of Things (IoT) is an inevitable trend in order to meet high-quality demands for the forthcoming 6G communications. In this paper, we study a secure intelligent reflecting surface (IRS)-assisted IoT system where malicious eavesdropper trying to sniff out the desired information from the transmission links between the IRS and legitimate IoT devices. We discuss the system overall performance and propose a hybrid resource allocation scheme for maximizing the secrecy capacity and secrecy energy efficiency. In order to achieve the trade-off between transmission reliability, communication security, and energy efficiency, we develop a quantum-inspired marine predator algorithm (QMPA) for realizing rational configuration of system resources and prevent from eavesdropping. Simulation results demonstrate the superiority of the QMPA over other strategies. It is also indicated that proper IRS deployment and power allocation are beneficial for the enhancement of system overall capacity.

• Journal of Ceramic Processing Research
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• v.13 no.spc2
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• pp.336-340
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• 2012

Wide band gap p-type hydrogenated amorphous silicon oxide (a-SiO:H) buffer layer has been used at the interface of transparent conductive oxide (TCO) and hydrogenated amorphous silicon (a-Si:H) p-type layer of a p-i-n type a-Si:H solar cell. Introduction of 5 nm thick buffer layer improves in blue response of the cell along with 0.5% enhancement of photovoltaic conversion efficiency (η). The cells with buffer layer show higher open circuit voltage (Voc), fill factor (FF), short circuit current density (Jsc) and improved blue response with respect to the cell without buffer layer.