• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.608-608
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• 2013

직선운동하는 하전입자의 진행방향에 수직한 평면상에 서로 직교하는 전기장과 자기장을 걸어주면, 하전입자에는 전기장에 의한 힘 $F_E$와 자기장과 속도 v에 의한 로렌츠력 $F_B=q(v{\times}B)$가 동시에 작용하게 된다. 이때 Wien 조건 $F_B=-F_E$를 만족하는 질량 $m_A$과, 에너지 $E_A$를 가지는 하전입자 A는 휘지 않고 직선운동을 계속하나, 하전입자 A와 다른 에너지 $E_B(=E_A+{\delta}E)$나 질량 $m_B$ $(=m_A+{\delta}m)$을 가지는 하전입자는 휘게 되며, 그 휘는 정도는 ${\delta}E$나 ${\delta}m$에 비례하게 된다. 이 현상을 이용하여 다양한 종류의 에너지 또는 질량 분석기가 독일, 미국, 일본 등의 분석기기 선진국에서 개발되어 왔고, 전자현미경의 이미지 필터로도 활용되고 있으며, 통상 EXB 필터 또는 발명자의 이름을 딴 Wien 필터로 불리어지고 있다. $E{\times}B$ 필터는 일반적인 하전입자빔 렌즈와 다른 광학특성을 가진다. 예를 들면 3차 이상의 기하 수차만 가지는 일반 렌즈와는 달리 $F_B$, $F_E$ 전자기력에 의해 다양한 2차 기하 수차를 가지게 되며, 초점거리 등의 1차 광학 특성도 일반 렌즈와는 다른 경향을 보여준다. 본 발표에서는 $E{\times}B$ 필터의 전후로 각각 6극자+4극자를 조합시킨 보정기를 배치시켜 필터의 에너지 분해능의 성능을 향상시킬 수 있음을 빔 궤도 방정식을 분석적으로 계산하여 보여준다. 위 에너지 필터 구성에서 4극자는 1차 광학 특성을 조정하는 역할을 하며 6극자는 2차 수차를 줄여주는 역할을 한다. 수치해석을 통해서는 6극자+4극자를 조합시킨 보정기와 $E{\times}B$ 필터의 좀더 정확한 전극 전압 등의 제어 수치를 추출하고, 빔 궤도 방정식 분석을 통한 수차 보정 알고리즘이 유효함을 보여준다.

• Journal of the Korean Magnetics Society
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• v.2 no.2
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• pp.114-118
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• 1992

아크로를 이용하여 제작한 NdF $e_{12-x}$ $Ti_{x}$ (1 .leq. x .leq. 2) 합금의 상분석 결과 이들 합금은 ThM $n_{12}$ 구조의 경자성상(1-12상) 과 반강자성의 F $e_{2}$Ti 및 연자성의 .alpha. -Fe 등으로 구성되며, x=1.3 인 NdF $e_{10.7}$ $Ti_{1.3}$ 조성에서 단상에 가까운 ThM $n_{2}$ 구조가 얻어짐이 밝혀졌다. 한편, 합금중의 1-12 상은 50 .mu. m - 100 .mu. m 의 사각주 형태로 생성되며, FeTi은 1-12상의 결정립계에 고립된 입자의 형태로 존재한다. NdF $e_{10.7}$ $Ti_{1.3}$ 합금을 질화처리할 경우 단위포의 체적, 자화, 이방성자장 및 큐리온도가 증가하며, 이합금을 500 .deg. C 에서 15분간 질화처리한 NdF $e_{10.7}$ $Ti_{1.3}$ $N_{x}$ 의 비포화자화, 이방성자장 및 큐리온 도는 각각, .sigma. $_{s}$ =128 A $m^{2}$/kg $H_{A}$=6400 kA/m (80 kOe) 및 Tc=470 .deg. C로 질화처리 전에 비하여 크게 증가한다.크게 증가한다. 증가한다.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.251-265
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• 2000

S $m_{2}$F $e_{17}$ $N_{x}$ film magnets using a S $m_{2}$F $e_{17}$ target were prepared at $N_{2}$ gas atmosphere using a Nd-YAG laser ablation technique. The effect of nitrogen pressure, deposition temperature, pulsation time and film thickness on the structure and magnetic properties of S $m_{2}$F $e_{17}$ $N_{x}$ film were studied. Increasing the nitrogen pressure up to 5 atm. was confirmed to lead the formation of complete S $m_{2}$F $e_{17}$ $N_{x}$ compound. Optimized magnetic properties with the nitrogenation temperature ranging over 500-53$0^{\circ}C$ could be obtained by extending the nitrogenation time up to 4 hours. Relatively low coercivities of 400~600 Oe were exhibited from the S $m_{2}$F $e_{17}$ $N_{x}$ films having the thickness of 50~100 nm while 4$\pi$ $M_{s}$ of 10~12 kG could be achieved. In-plane anisotropic characteristic, which was the basic goal in this study, was achieved by controlling the nitrogenation parameters.ameters.ers.ameters.

• The Transactions of the Korea Information Processing Society
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• v.1 no.2
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• pp.184-193
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• 1994

This paper considers the Updating Minimum-weight Spanning Tree Problem(UMP), that is, the problem to update the Minimum-weight Spanning Tree(MST) in response to topology change of the network. This paper proposes the algorithm which reconstructs the MST after several links deleted and added. Its message complexity and its ideal-time complexity are Ο(m＋n log(t＋f)) and Ο(n＋n log(t＋f)) respectively, where n is the number of processors in the network, t(resp.f) is the number of added links (resp. the number of deleted links of the old MST), And m=t＋n if f=Ο, m=e (i.e. the number of links in the network after the topology change) otherwise. Moreover the last part of this paper touches in the algorithm which deals with deletion and addition of processors as well as links.

• Journal of the Chungcheong Mathematical Society
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• v.8 no.1
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• pp.111-117
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• 1995

A function $f:{\Omega}{\rightarrow}X$ is called intrinsically-separable valued if there exists $E{\in}{\Sigma}$ with ${\mu}(E)=0$ such that $f({\Omega}-E)$ is a separable in X. For a given Dunford integrable function $f:{\Omega}{\rightarrow}X$ and a weakly compact operator T, we show that if f is intrinsically-separable valued, then f is Pettis integrable, and if there exists a sequence ($f_n$) of Dunford integrable and intrinsically-separable valued functions from ${\Omega}$ into X such that for each $x^*{\in}X^*$, $x^*f_n{\rightarrow}x^*f$ a.e., then f is Pettis integrable. We show that a function f is Pettis integrable if and only if for each $E{\in}{\Sigma}$, F(E) is $weak^*$-continuous on $B_{X*}$ if and only if for each $E{\in}{\Sigma}$, $M=\{x^*{\in}X^*:F(E)(x^*)=O\}$ is $weak^*$-closed.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.4
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• pp.310-318
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• 2015

In this paper, dual-port eFuse OTP (one-time programmable) memory cells with smaller cell sizes are used, a single VREF (reference voltage) is used in the designed eFuse OTP IP (intellectual property), and a BL (bit-line) sensing circuit using a S/A (sense amplifier) based D F/F is proposed. With this proposed sensing technique, the read current can be reduced to 3.887mA from 6.399mA. In addition, the sensing resistances of a programmed eFuse cell in the program-verify-read and read mode are also reduced to $9k{\Omega}$ and $5k{\Omega}$ due to the analog sensing. The layout size of the designed 32-bit eFuse OTP memory is $187.845{\mu}m{\times}113.180{\mu}m$ ($=0.0213{\mu}m2$), which is confirmed to be a small-area implementation.

• 전기의세계
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• v.15 no.2
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• pp.1-7
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• 1966

It is well known that the speed of induction motor can be controlled in wide range by changing the second exciting e.m.f. of rotor circuit, but that is well not practised because of its complicated system. In order to simplify such a system, the Kramer system of which silicon rectifier substitutes for synchronous converter has analyzed in this paper. The result of this investigation show that in this system, only the equivlent synchronous speed it changed by second exciting e.m.f., but the mechanical output power, torque and power factor is not changed, and that this system is able to compensate the regulated speed on account of the load changed.

• Proceedings of the KIEE Conference
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• 2001.07b
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• pp.855-858
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• 2001

The single transformer appeared the electro-magnetic force must be constructed to support it. it must construct the single transformer to supporting the electro-magnetic force appeared by the cut-off current. the problem is that the electro-magnetic occurs the modification of the single transformer and an serious accident. In the case of the molding-transformer, the part of the molding cast used in the construction occurs the crack, because of the strong force. therefore, in this paper, the molding material used in the molding-transformer is settled by comparing the results from commercial soft ware of F.E.M and a out-equipment circuit.

• Communications of the Korean Mathematical Society
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• v.36 no.3
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• pp.401-411
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• 2021

A Diophantine m-tuple is a set {a₁, a₂, …, a_m} of positive integers such that a_ia_j+1 is a perfect square for all 1 ≤ i < j ≤ m. Let E_k be the elliptic curve induced by Diophantine triple {F_2k, 5F_2k+2, 3F_2k + 7F_2k+2}. In this paper, we find the structure of a torsion group of E_k, and find all integer points on E_k under assumption that rank(E_k(ℚ)) = 1 and some further conditions.

• Communications of the Korean Mathematical Society
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• v.29 no.2
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• pp.285-293
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• 2014

Let M be a closed, symplectic connected Riemannian manifold and f a symplectomorphism on M. We prove that if f is $C^1$-stably weak shadowable on M, then the whole manifold M admits a partially hyperbolic splitting.