반도체 소자 모델링을 위한 변분법에 관한 연구

학위논문(박사) - 한국과학기술원 : 전기및전자공학과, 1997.2, [ [iv], 78 p. ]Variational formulation of Poisson``s equation with Boltzmann carrier statistics at quasi-equilibrium is introduced. This formulation allows us to find analytical solutions of the potential distribution in multi-dimensional semiconductor devices without resort to numerical calculation with resonably good accuracy. To demonstrate this approach, short-channel effects in the threshold voltage and subthreshold swing of fully depleted SOI MOSFET``s are analyzed. The usefulness of our idea is extended further to determine the quasi-fermi potential of the floating gate of an EEPROM device, which has been determine to be very difficult to find by the conventional methods. A novel high voltage junction termination structure of Coupled Floating Field Plate(CFFP) is also proposed. This structure has the advantages of more compatibility with modern planar integrated circuit fabrication process compared with field plate structure and stronger surface passivation capability compared with multiple field limiting ring structure. The numerical optimization is performed by the two dimensional device simulation with adopting variational method to determine floating field plate potentials. Our optimization example shows that about 80% of ideal plane junction breakdown voltage can be achieved for 1,130V device.한국과학기술원 : 전기및전자공학과

Molecularly controlled interfacial layer strategy toward highly-efficient simple-structured organic light-emitting diodes

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Primary Palatoplasty With Intravelar Veloplasty Using Acellular Dermal Matrix Interpositional Graft

The aim of this study was to analyze the effect of acellular dermal matrix (ADM) on fistula formation after primary palatoplasty using intravelar veloplasty for levator veli palatini muscle repair. This single-center retrospective study included patients who underwent primary palatoplasty with intravelar veloplasty for reorientation of the levator veli palatini muscles between April 2014 and March 2018. In the control group (group A) conventional intravelar veloplasty was performed, while in the ADM group (group B) intravelar veloplasty using ADM was performed. The study sample was composed of 162 patients, 81 in each of the 2 groups (A and B). In group B, securely dissected muscles were overlapped, and a pentagon-shaped ADM (AlloDerm, LifeCell Corp., Branchburg, NJ) of 1.6 mm mean thickness, 11.3 mm mean width, and 14.4 mm mean length was designed, and placed under the repaired levator muscle sling. The outcome variable was the occurrence of oronasal fistula within the first 6 months after surgery. Postoperative fistula formation was reported in 6 patients in group A (7.4%) and in 5 patients in group B (6.2%). There was no statistically significant difference between the 2 groups (P = 0.755). There were 7 cases of ADM exposure and 2 cases of wound dehiscence in group B. The results of this study demonstrated that ADM use did not have any disadvantage with respect to oronasal fistula complications after intravelar veloplasty for levator veli palatini muscle repair

Polyethylene Imine as an Electron Injection Interlayer for High Efficient Inverted Polymer Light-Emitting Diodes

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한 점으로부터 Dilation이 제한된 최소 신장 트리

학위논문(석사) - 한국과학기술원 : 전산학전공, 2009.2, [ iv, 25 p. ]A geometric network is a weighted undirected graph \sl{G} whose vertices are points in $\mathbb{R}^d$, and weights are the Euclidean length of its edges. The graph distance between the two vertices in a geometric network is the length of shortest path connecting those points. The dilation of \sl{G} is the maximum factor by which graph distance differs from the Euclidean distance between two points. The anchored dilation of \sl{G} is the dilation from an anchor, a fixed given point, to other vertices. We consider the Anchored Dilation Bounded Minimum Spanning Tree(ADBMST) Problem. The problem is to build the spanning tree which has the minimum weight among all spanning trees with the anchored dilation at most $\delta$ for a given set of \sl{n} points S and maximum dilation \delta > 1. I show that the problem is NP-hard by showing that there is a polynomial reduction from the Knapsack Problem to ADBMST Problem. I also suggest a simple algorithm to build an approximated tree.한국과학기술원 : 전산학전공

Highly Efficient Inverted Polymer Light-Emitting Diodes with Polyethylene Imine Electron Injection Interlayer

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