• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2395-2397
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• 2005

A low voltage operated piezoelectric RF MEMS in-line switch has been realized by using silicon bulk micromachining technologies for advanced mobile/wireless applications. The developed RF MEMS in-line switches were comprised of four piezoelectric cantilever actuators with an Au contact metal electrode and a suspended Au signal transmission line above the silicon substrate. The measured operation dc bias voltages were ranged from 2.5 to 4 volts by varying the thickness and the length of the piezoelectric cantilever actuators, which are well agreed with the simulation results. The measured isolation and insertion loss of the switch with series configuration were -43dB and -0.21dB (including parasitic effects of the silicon substrate) at a frequency of 2GHz and an actuation voltage of 3 volts.

• International Journal of Computer Science & Network Security
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• v.24 no.2
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• pp.155-157
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• 2024

Internet of Things (IoT) integrated with the Blockchain is the state of the art for keen cultivation and agriculture. Recently the interest in agribusiness information is enlarging owing to the fact of commercializing the smart farming technology. Agribusiness information are known to be untidy, and experts are worried about the legitimacy of information. The blockchain can be a potential answer for the expert's concern on the uncertainty of the agriculture data. This paper proposes an Agri-Banana plant system using Blockchain integrated with IoT. The system is designed by employing IoT sensors incorporated with Hyperledger fabric network, aims to provide farmers with secure storage for preserving the large amounts of IoT and agriculture data that cannot be tampered with. A banana smart contract is implemented between farmer peer and buyer peer of two different organizations under the Hyperledger fabric network setup aids in secure transaction of transferring banana from farmer to buyer.

• Korean Journal of Mathematics
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• v.6 no.1
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• pp.127-135
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• 1998

Let ${\rho}(A)$ and ${\rho}(B)$ denote the orders of entire functions $A(z)$ and $B(z)$ respectively. Suppose that ${\rho}(A)$ > 1 and 0 < ${\rho}(B){\leq}\frac{1}{2}$, and that ${\rho}$(A) is not an integer. Then it is shown that every nonconstant solution $f$ of $f^{{\prime}{\prime}}+A(z)f^{\prime}+B(z)f=0$ is of infinite order if all the zeros of $A(z)$ lie in a certain angular sector depending on its genus. In addition, we investigate some growth properties of $A(z)$.

• Bulletin of the Korean Mathematical Society
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• v.38 no.2
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• pp.399-412
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• 2001

In this paper, we consider that the q-analogue of w$\omega-Bernoulli numbers\; B_i(\omega, q)$. And we calculate the sums of products of two q-analogue of $\omega-Bernoulli numbers B_i(\omega, q)$ in complex cases. From this result, we obtain the Euler type formulas of the Carlitz´s q-Bernoulli numbers $\beta_i(q)$ and q-Bernoulli numbers $B_i(q)$. And we also calculate the p-adic Stirling type series by the definition of $B_i(\omega, q)$ in p-adic cases.

• Journal of Information Technology Applications and Management
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• v.9 no.1
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• pp.127-142
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• 2002

This study examines various factors which influence the degree of Participation In B to B e-Marketplace. Based on literature review, six factors such as Information provision, IT infrastructure, trust, aggregation, new customer creation, and matching are identified. To collect the empirical data, survey methodology has been utilized. A total of 32 companies have returned completed responses. The results of analysis show high interdependencies between six factors and the degree of participation in e-Marketplace. In particular, aggregation is found to be the most influential factor. Additional analysis reveals that firms participating highly in e-Marketplace recognize aggregation and new customer creation the most important factors while less participating firms see IT infrastructure more important.

• Nonlinear Functional Analysis and Applications
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• v.26 no.2
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• pp.303-322
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• 2021

The concepts of new classes of mappings are introduced in the spaces which are more general space than the usual metric spaces. The existence and uniqueness of common fixed points and fixed point results are established in the setting of complete complex valued b-metric spaces. An illustration is given by establishing the existence of solution of periodic differential equations in the framework of a complete complex valued b-metric spaces.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.8
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• pp.1465-1470
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• 2006

This paper presents a design of low power CMOS LNA(Low Noise Amplifier) for 2.4 GHz ZigBee applications that is a promising international standard for short area wireless communications. The proposed circuit has been designed using TSMC $0.18{\mu}m$ CMOS process technology and two stage cascade topology by current reuse technique. Two stage cascade amplifiers use the same bias current in the current reused stage which leads to the reduction of the power dissipation. LNA design procedures and the simulation results using ADS(Advanced Design System) are presented in this paper. Simulation results show that the LNA has a extremely low power dissipation of 1.38mW with a supply voltage of 1.0V. This is the lowest value among LNAs ever reported. The LNA also has a maximum gain of 13.38dB, input return loss of -20.37dB, output return loss of -22.48dB and minimum noise figure of 1.13dB.

• Journal of Electrochemical Science and Technology
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• v.14 no.1
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• pp.51-58
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• 2023

The effective detection of human chorionic gonadotropin (HCG) is considerably important for the clinical diagnosis of both of early pregnancy and nonpregnancy-related diseases. In this work, a simple and sensitive electrochemical sandwich-type immunosensing platform was designed by synthesizing b-cyclodextrin (CD) functionalized graphene (CD/GN) hybrid as simultaneously sensing platform and signal transducer coupled with rhodamine b (RhB) as probe. In brief, GN offers large surface area and high conductivity, while CD exhibits superior host-guest recognition capability, thus the primary antibody (Ab1) of HCG can be bound into the cavities of CD/GN to form stable Ab1/CD/GN inclusion complex; meanwhile, the secondary antibody (Ab2) and RhB can also enter into the cavities, producing RhB/Ab2/CD/GN complex. Then, by using Ab1/CD/GN as sensing platform and RhB/Ab2/CD/GN as signal transducer (in which RhB was signal probe), a simple sandwich-type immunosensor was constructed. Under the optimum parameters, the designed immunosensor exhibited a considerable low analytical detection of 1.0 pg mL^-1 and a wide linearity of 0.002 to 10.0 ng mL^-1 for HCG, revealing the developed sandwich-type electrochemical immunosensing platform offered potential real applications for the determination of HCG.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.77-84
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• 2007

In this parer, a wideband low-noise amplifier (LNA) has been realized in a 0.18mm CMOS technology for the applications of subsampling direct-conversion RF receivers. By exploiting the inverter-type transimpedance input stage with a 3rd-order Chebyshev matching network, the wideband LNA demonstrates the measured results of the -3dB bandwidth of 5.35GHz, the power gain (S21) of $12\sim18dB$, the noise figure (NF) of $6.9\sim10.8dB$, and the broadband input/output impedance matching of less than -10dB/-24dB within the bandwidth, respectively. The chip dissipates 32.4mW from a single 1.8V supply, and occupies the area of $0.56\times1.0mm^2$.

• Nuclear Engineering and Technology
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• v.43 no.2
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• pp.187-194
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• 2011

Korea Nuclear Fuel is developing the X-GEN fuel which shows high performance and robust reliability for the worldwide supply. However, the simplified code systems such as CESEC-III which were developed in 1970s are still used in the current Non-LOCA safety analysis of OPR1000 and APR1400 plants. Therefore, it is essential to secure an advanced safety analysis methodology to make the best use of the merits of X-GEN fuel. To accomplish this purpose, the $\b{i}$ntegrated $\b{s}$afety $\b{a}$nalysis $\b{m}$ethodology (iSAM), is developed by selecting the best-estimate thermal-hydraulic code RETRAN. iSAM possesses remarkable advantages, such as generality, integrity, and designer-friendly features. That is, iSAM can be applied to both OPR1000 and APR1400 plants and uses only one computer code, RETRAN, in the whole scope of the non-LOCA safety analyses. Also the iSAM adopts the unique and automatic initialization and run tool, $\b{a}$utomatic $\b{s}$teady-$\b{s}$tate $\b{i}$nitialization and $\b{s}$afety analysis too l (ASSIST), to enable unhandy designers to use the new design code RETRAN without difficulty. In this paper, a brief overview of the iSAM is given, and the results of applying the iSAM to typical non-LOCA transients being checked during the reload design are reported. The typical non-LOCA transients selected are the single control element assembly withdrawal (SCEAW) accident, the asymmetric steam generator transients (ASGT), the locked rotor (LR) accident, and bank CEA withdrawal (BCEAW) event. Comparison to current licensing results shows a close resemblance; thus, it reveals that the iSAM can be applied to the non-LOCA safety analysis of OPR1000 and APR1400 plants.