• Journal of IKEEE
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• v.28 no.1
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• pp.116-122
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• 2024

AMBA AHB-Lite bus is widely used in on-chip bus protocol for low-power and cost-effective SoC. However, it lacks built-in error detection and correction for end-to-end data integrity. This can lead to data corruption and system instability, particularly in harsh environments like automotive applications. To mitigate this problem, this paper proposes the application of SEC-DED (Single Error Correction-Double Error Detection) to AMBA AHB-Lite bus. It aims not only to detect errors in real-time but also to correct them, thereby enhancing end-to-end data integrity. Simulation results demonstrate real-time error detection and correction when errors occur, which bolsters end-to-end data integrity of automotive on-chip bus.

• Journal of IKEEE
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• v.28 no.1
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• pp.33-37
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• 2024

In this paper, we report the design and the measurement of a X-band low noise amplifier (LNA) monolithic microwave integrated circuit (MMIC) using a 0.25 ㎛ gate length microstrip GaN-on-SiC high electron mobility transistor (HEMT) technology. The developed X-band GaN-based LNA MMIC achieves small signal gain of 22.75 dB ~ 25.14 dB and noise figure of 1.84 dB ~ 1.94 dB in the desired band of 9 GHz to 10 GHz. Input and output return loss values are -11.36 dB ~ -24.49 dB and -11.11 dB ~ -17.68 dB, respectively. The LNA MMIC can withstand 40 dBm (10 W) input power without performance degradation. The chip dimensions are 3.67 mm × 1.15 mm. The developed GaN-based LNA MMIC is applicable to various X-band applications.

• Journal of IKEEE
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• v.28 no.1
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• pp.53-64
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• 2024

With the advancement of NLP(Natural Language Processing) models, conversational AI such as ChatGPT is becoming increasingly popular. To enhance processing speed and reduce power consumption, it is important to implement the Transformer algorithm, which forms the basis of the latest natural language processing models, in hardware. In particular, the multi-head attention and feed-forward network, which analyze the relationships between different words in a sentence through matrix multiplication, are the most computationally intensive core algorithms in the Transformer. In this paper, we propose a new variable systolic array based on the number of input words to enhance matrix multiplication speed. Quantization maintains Transformer accuracy, boosting memory efficiency and speed. For evaluation purposes, this paper verifies the clock cycles required in multi-head attention and feed-forward network and compares the performance with other multipliers.

• Korean Journal of Materials Research
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• v.34 no.3
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• pp.152-162
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• 2024

In this study, we introduce a novel TiN/Ag embedded TiO₂/FTO resistive random-access memory (RRAM) device. This distinctive device was fabricated using an environmentally sustainable, solution-based thin film manufacturing process. Utilizing the peroxo titanium complex (PTC) method, we successfully incorporated Ag precursors into the device architecture, markedly enhancing its performance. This innovative approach effectively mitigates the random filament formation typically observed in RRAM devices, and leverages the seed effect to guide filament growth. As a result, the device demonstrates switching behavior at substantially reduced voltage and current levels, heralding a new era of low-power RRAM operation. The changes occurring within the insulator depending on Ag contents were confirmed by X-ray photoelectron spectroscopy (XPS) analysis. Additionally, we confirmed the correlation between Ag and oxygen vacancies (V_o). The current-voltage (I-V) curves obtained suggest that as the Ag content increases there is a change in the operating mechanism, from the space charge limited conduction (SCLC) model to ionic conduction mechanism. We propose a new filament model based on changes in filament configuration and the change in conduction mechanisms. Further, we propose a novel filament model that encapsulates this shift in conduction behavior. This model illustrates how introducing Ag alters the filament configuration within the device, leading to a more efficient and controlled resistive switching process.

• Journal of The Korean Institute of Defense Technology
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• v.5 no.3
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• pp.18-28
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• 2023

The threat of drones is widely occurring not only in the military field but also for important national facilities such as airports and nuclear power plants. Drones are very diverse in types and control methods, so it is not easy to have a uniform defense method and system, and with the development of drone technology, the war paradigm using drones as weapons is also changing. In particular, advances in drone technology are improving the efficiency and accuracy of reconnaissance and attack missions. Nevertheless, it is very difficult to secure research cases on military operation of drones due to difficulties in obtaining information on military operations. Therefore, in this study, we try to create basic data that can effectively establish a plan for performing reconnaissance and attack missions by deriving each operational aspect through analysis of operation cases of reconnaissance and attack drones.

• Journal of Electrochemical Science and Technology
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• v.15 no.3
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• pp.321-344
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• 2024

Transition metal compounds (TMCs) are being researched as promising electrode materials for electrochemical energy storage devices (supercapacitors). Among TMCs, transition metal phosphates (TMPs) have good, layered structures owing to open framework and protonic exchange capability among different layers, good surface area due to engrossed porosity, rich active redox reaction sites owing to octahedral structure and variable valance metallic ions. Hence TMPs become more ideal for supercapacitor electrode materials compared to other TMCs. However, TMPs have got some issues like low conductivity, rate performance, stability, energy, and power densities. But these problems can be addressed by making their composites with carbonaceous materials, e.g., carbon nanotubes (CNTs), graphene oxide (GO), graphitic carbon (GC), etc. A few factors like high surface area, excellent electrical conductivity of carbon materials and variable valence metal ions in TMPs caused great enhancement in their electrochemical performance. This article tries to discuss and compare the published data, majorly in last decade, regarding the electrochemical energy storage potential of pristine unary, binary, and ternary TMPs and their hybrid composites with carbonaceous materials (CNTs, GOs/rGOs, GC, etc.). The electrochemical performance of the hybrids has been reported to be higher than the pristine counterparts. It is hoped that the current review will open a new gateway to study and explore the high performance TMPs based supercapacitor materials.

• Journal of IKEEE
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• v.28 no.3
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• pp.303-309
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• 2024

This paper proposes a high-gain phased array antenna that can provide private network communication services for large office spaces, factories, and other large-scale facilities, specifically designed for millimeter-wave band 5G (5th generation) networks. The proposed antenna features a 4×4 array structure with eight sub-arrays, each consisting of a 1×2 series array. To achieve high side-lobe characteristics, an offset array structure is applied by shifting even-numbered rows by one unit, combined with power tapering to adjust the size of individual radiating elements. This design achieves a high side-lobe level (SLL) of 22.3 dB and a high gain of 18.1 dBi. Additionally, the antenna provides gain characteristics of at least 15.2 dBi and 17.4 dBi within the intended beam steering range of ±45° in the azimuth direction and ±10° in the elevation direction, ensuring smooth communication services over a wide service area.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.183-192
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• 1999

The derivative equation measured of a ${\Delta}MV=Kp*{(EVn-EVn-1)+\frac{1}{Ki/S}* EVn+(Kd/S)*(2PVn-1-PVn-PVn-1)}$ is used on the machine apparatus of industrial field, but this par doesn\`t able to educate now, because we didn\`t have the implementation device of PID module, so the principle implementation system of the PID Module is manufactured and developed. Through this system, the implementation system of PID Module is practiced with that the SV and the set of P, I, D is set on the derivative equation measured of PID. A things to be known of this experiment result is flow. 1)PID module is known that had to be used with the module of A/D and D/A. 2) In process of PV is approached to the SV to follow Kp, Ti and Td to cause a constant of set value on the $MVp=Kp*EV, MV=\frac{1}{Ki}{\int}EVdt, MVd=Td\frac{d}{dt}EV$, the variable rate of E and Kp, Td, Ti in that table 1 is analysed, is same as flow. (1)If Kp is high, PV is near fast to the SV, but Kp is small, PV is near slowly to the SV. (2)If Ki is shot, PV is close fast to the SV, but Ti is high, PV is close slowly to the SV (3)If Td is high, the variable rate of E press hardly when because it doesn\`t increase, but Td is small, the variable rate of E press not hardly, upper with 1), 2), PID module is supposed that be able to do the A/S and an implementation of that apparatus, and getting a success of aim that an engineer want, on control of temperature, tension, velocity, amount of flow, power of wind end so on, to get the principle of automatic implementation in industrial field with cooperation of A/D and D/A module.

• Journal of the Korean Electrochemical Society
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• v.8 no.3
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• pp.139-145
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• 2005

[ $SnO_x$ ] films on the flexible substrate of PET film were prepared at ambient temperature under a $(CH_3)_4Sn(TMT: tetra-methyl tin)-H_2-O_2$ atmosphere in order to obtain transparent conductive polymer by using ECR-MOCVD(Electro Cyclotron Resonance Metal Organic Chemical Yfpor Deposition) system. The prepared $SnO_x$ thin films show generally over $90\%$ of optical transmittance at wavelength range of 380-780nm and about $1\times10^{-2\~3}ohm{\cdot}cm$ of electrical resistivity. In the present study, effects of $O_2/TMT\;and\;H_2/TMT$ mole ratio on the properties of $SnO_x$ films are investigated and the other process parameters such as microwave power, magnetic current power, substrate distance and working pressure are fixed. Based on our experimental results, the $SnO_x$ film composition ratio of Sn and O directly influences on the electrical and optical properties of the films prepared. The $SnO_x$ film with low electric resistivity and high transmittance could be obtained by controlling the process parameters such as $O_2/TMT\;and\;H_2/TMT$ mole ratio, which play an important role to change the composition ratio between Sn and O. An increase of $O_2/TMT$ mole ratio brought on the increases 0 content in the $SnO_x$ film. On the other hand, an increase of $H_2/TMT$ mole ratio lead to decreases the oxygen content in the film. The optimized composition ratio of oxygen : tin Is determined as 2.4: 1 at $O_2/TMT$ of 80 and $H_2/TMT$ of 40 mole ratio, respectively.

• Korean Chemical Engineering Research
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• v.60 no.1
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• pp.86-92
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• 2022

Recently, the bio-healthcare market is enlarging worldwide due to various reasons such as the COVID-19 pandemic. Among them, biometric measurement and analysis technology are expected to bring about future technological innovation and socio-economic ripple effect. Existing systems require a large-capacity battery to drive signal processing, wireless transmission part, and an operating system in the process. However, due to the limitation of the battery capacity, it causes a spatio-temporal limitation on the use of the device. This limitation can act as a cause for the disconnection of data required for the user's health care monitoring, so it is one of the major obstacles of the health care device. In this study, we report the concept of a standalone healthcare monitoring module, which is based on both triboelectric effects and electromagnetic effects, by converting biomechanical energy into suitable electric energy. The proposed system can be operated independently without an external power source. In particular, the wireless foot pressure measurement monitoring system, which is rationally designed triboelectric sensor (TES), can recognize the user's walking habits through foot pressure measurement. By applying the triboelectric effects to the contact-separation behavior that occurs during walking, an effective foot pressure sensor was made, the performance of the sensor was verified through an electrical output signal according to the pressure, and its dynamic behavior is measured through a signal processing circuit using a capacitor. In addition, the biomechanical energy dissipated during walking is harvested as electrical energy by using the electromagnetic induction effect to be used as a power source for wireless transmission and signal processing. Therefore, the proposed system has a great potential to reduce the inconvenience of charging caused by limited battery capacity and to overcome the problem of data disconnection.