• 한국자기공명학회논문지
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• 제13권2호
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• pp.135-142
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• 2009

$^{195}Pt$ NMR measurements were performed to deduce the variation of local density of states at the Fermi energy ($E_F$-LDOS) at the surface of carbonsupported Pt catalysts due to the addition of $Nafion^{(R)}$ ionomer in the metalelectrode-assembly for fuel cells. The results showed that the EF-LDOS at the surface of Pt particles was enhanced by the addition of $Nafion^{(R)}$ ionomers whereas it was uninfluenced in the inner (bulk) part of the Pt particles. This suggests that the effects of ionomers on the electronic states of the Pt particle surface are related to the electrochemical activity of the catalysts.

• JSTS:Journal of Semiconductor Technology and Science
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• 제9권2호
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• pp.85-90
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• 2009

This paper presents a single supply PLC SoC ASIC with a built-in analog Front-end circuit. To achieve the low power consumption along with low cost, this PLC SoC employs fully CMOS Analog Front End (AFE) and several LDO regulators (LDOs) to provide the internal power for Logic Core, DAC and Input/output Pad driver. The receiver part of the AFE consists of Pre-amplifier, Gain Amplifier and 1 bit Comparator. The transmitter part of the AFE consists of 10 bit Digital Analog Converter and Line Driver. This SoC is implemented with 0.18 ${\mu}m$ 1 Poly 5 Metal CMOS Process. The single supply voltage is 3.3 V and the internal powers are provided using LDOs. The total power consumption is below 30 mA at stand-by mode to meet the Eco-Design requirement. The die size is 3.2 $\times$ 2.8 $mm^{2}$.

• 한국진공학회지
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• 제2권3호
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• pp.339-345
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• 1993

계면의 원자구조와 전자특성간의 상관성을 연구하기 위하여 GaAs-Ge(AlAs) 이종접합에서 전자의 국소상태밀도(LDOS)를 계산하였다. 본 연구에서는 tight-binding recursion 방법을 기초로 하여 계면의 국소상태밀도로부터 band-offsets, 계면형성에너지, 계면결합의 bond order 등을 연구하는 보다 편리한 방법을 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.544-554
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• 1991

Using the Huckel method, we obtain the analytical expressions for eigenvalues and eigenvectors of s.c., f.c.c. and b.c.c. clusters of rectangular parallelepiped shape, and of an arbitrary size. Our formula converage to those derived from the Bloch sum, in the limit of infinite extension. DOS and LDOS reveal that the major contribution of the states near Fermi level originates from the surface atoms, also symmetry of DOS curves disappears by the introduction of 2nd nearest neighbor interactions, in all the cubic lattices. An accumulation of the negative charges on surface of cluster is observed.

• 대한전자공학회논문지SD
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• 제46권10호
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• pp.31-39
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• 2009

본 논문은 전력선 통신용(PLC) SoC ASIC으로 내장된 Analog Front-end(AFE)를 바탕으로 낮은 소비 전력과 저 가격을 달성할 수 있었으며, CMOS공정으로 구현된 AFE와, 1.8V동작의 Core Logic구동용 LDO, ADC, DAC와 IO pad를 구동하기 위한 LDO로 구성되어 있다. AFE는 Pre-amplifier, Programmable gain Amplifier와 10bit ADC의 수신 단으로 구성되며, 송신 단은 10bit differential DAC, Line Driver로 구성되어 있다. 본 ASIC은 0.18 um 1 Poly 5 Metal CMOS로 구현 되었으며, 동작전압은 3.3 V단일 전원만 사용하였고, 이때 소모 전력은 대기 시에 30mA이며, 동작 시 전력은 300mA으로 에코 디자인 요구를 만족하게 하였다. 본 칩의 Chip size는 $3.686\;{\times}\;2.633\;mm^2$ 이다.

• EDISON SW 활용 경진대회 논문집
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• 제3회(2014년)
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• pp.478-482
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• 2014

Graphene have renewed considerable interest in inorganic, two-dimensional materials for future electronics. However, graphene does not have a bandgap, it is limited to apply directly to transistors and logic devices. Hence, other layered materials such as molybdenum disulphide ($MoS_2$) have been investigated to address this challenge. Here, we find that the nature of contacts plays a more important role than the semiconductor itself. In order to understand the nature of $MoS_2$/metal contacts, we perform density functional theory electronic structure calculations based on linear combination of atomic for the geometry, bonding, binding energy, PDOS, LDOS and electronic structure. We choose Au as a contact metal because it is the most common contact metal. In this paper, we demonstrate $MoS_2$/Au contacts have a more promising potential in flexible nanoelectronics than $MoS_2$ itself.

• ETRI Journal
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• 제32권4호
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• pp.520-529
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• 2010

In this paper, we present a low-voltage low-dropout voltage regulator (LDO) for a system-on-chip (SoC) application which, exploiting the multiplication of the Miller effect through the use of a current amplifier, is frequency compensated up to 1-nF capacitive load. The topology and the strategy adopted to design the LDO and the related compensation frequency network are described in detail. The LDO works with a supply voltage as low as 1.2 V and provides a maximum load current of 50 mA with a drop-out voltage of 200 mV: the total integrated compensation capacitance is about 40 pF. Measurement results as well as comparison with other SoC LDOs demonstrate the advantage of the proposed topology.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.584-584
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• 2000

Electronic structures of ordered Fe$_3X (X = Al, Si), and their derivative ternary alloys of Fe_2TX (T = 3d transition metal) have been investigated by using the linearized muffin-tin orbital (LMTO) band method. The role of the coupling between substituted transition metal and its neighbors is investigated by calculating the magnetic moments and local density of states (LDOS). It is shown that it is essential to include the coupling beyond nearest neighbors in obtaining the magnetic moment of Fe alloy. The preferential sites of T impurities in Fe_3X are determined from the total energy calculations. The derivative ternary alloys of Fe_2TX have characteristic electronic structures of semi-metal for Fe_2VAI and (nearly) half-metal for Fe_2TAI (T = Cr, Mn) and Fe_2TSi (T = V, Cr, Mn)

• Bulletin of the Korean Chemical Society
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• 제12권1호
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• pp.39-47
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• 1991

A cluster made of $N_A,\;N_B\;and\;N_C$ atoms in the x, y and z directions respectively, is treated with Huckel method. We obtain the approximate expressions for the eigenvalues and eigenvectors of f.c.c., b.c.c. and h.c.p. clusters in closed forms. The maximum and minimum values of the band so obtained converge to those derived from the Bloch sum in the limit of infinite extension. For a small cluster (of $9{\times}9{\times}5$ atoms, for instance), LDOS from the analytical (approximate) solution manifests better agreement at the surface, than inside the bulk.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.538-561
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• 2020

Recommender Systems (RecSys) have a major role in e-commerce for recommending products, which they may like for every user and thus improve their business aspects. Although many types of RecSyss are there in the research field, the state of the art RecSys has focused on finding the user similarity based on sequence (e.g. purchase history, movie-watching history) analyzing and prediction techniques like Recurrent Neural Network in Deep learning. That is RecSys has considered as a sequence prediction problem. However, evaluation of similarities among the customers is challenging while considering temporal aspects, context and multi-component ratings of the item-records in the customer sequences. For addressing this issue, we are proposing a Deep Learning based model which learns customer similarity directly from the sequence to sequence similarity as well as item to item similarity by considering all features of the item, contexts, and rating components using Dynamic Temporal Warping(DTW) distance measure for dynamic temporal matching and 2D-GRU (Two Dimensional-Gated Recurrent Unit) architecture. This will overcome the limitation of non-linearity in the time dimension while measuring the similarity, and the find patterns more accurately and speedily from temporal and spatial contexts. Experiment on the real world movie data set LDOS-CoMoDa demonstrates the efficacy and promising utility of the proposed personalized RecSys architecture.