• 전자공학회논문지A
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• 제32A권3호
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• pp.143-151
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• 1995

The electrochemical impulse oscillations of the cathodic currents at the platinum group (Pt, Pd) electrode/(0.05M KHC$_{8}H_{4}O_{4}$) buffer solution interfaces have been studied using voltammetric, chronoamperometric, and electrochemical impedance methods. The periodic impulses of the cathodic currents are the activation controlled currents due to the hydrogen evolution reaction, and depend on the fractional surface coverage of the adsorbed hydrogen intermediate and potential. The oscillatory mechanism of the cathodic current impulses is connected with the unstable steady state of negative differential resistance. The widths and periods of the cathodic current impulses are 4ms or 5ms and 152.5ms or 305ms, respectively. The H$^{+}$ discharge reaction step is 38 or 61 times faster thatn the recombination reaction steps and the H$^{+}$ mass transport processes. The atom-atom recombination reaction step is twice faster thatn the atom-ion recombination reaction step. The two kinds of active sites corresponding to the atom-atom and atom-ion recombination reaction steps exist on the platinum group electrode surfaces.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2011년도 추계학술대회
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• pp.855-857
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• 2011

In this paper, we proposed EEAR(Efficient Energy Alternative Routing). This is a method of selecting a backup node for path routing management. When some node disconnection on the path routing, using pre-selected backup node provides immediately recover the path recovery. When selecting a Step-Parents node on the path management, the node' s energy level and distance information are cared in context-awareness. This not only increased the system' s capacity cost effectively, but also reduce transmission power entire nodes consume energy. As a result, each node could efficiently management and improves the life time for mobile host and extends system coverage.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.150-150
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• 2000

The adsorption geometry and the electronic property of Mg grown at room temperature on the Si(111)-7$\times$7 surface with various coverages have been studied by scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). At low Mg coverage, the Mg atoms preferentially adsorb at the center adatom sites of the faulted half of the Si(111)-7$\times$7 surface. The adsorbed Mg atom acts as nucleophile with respect to Si atoms thus forms a stable ionic bond with the substrate Si atoms. Above 1 Ml, the 7$\times$7 surface starts to be disrupted and an amorphous Mg overlayer is formed. The LEED shows either $\delta$7$\times$7 or 1$\times$1 pattern at this coverage. When more Mg atoms were exposed, a flat and broad {{{{ { 2} over {3 } }}}}{{{{ SQRT { 3} }}}}$\times${{{{ { 2} over {3 } }}}}{{{{ SQRT { 3} }}}}R30$^{\circ}$region evolves. A flat silicide is formed at first and multi-level Mg islands having hexagonal step edges develop with increasing coverage. The scanning tunneling spectroscopy (STS) confirms the electronic properties of these Mg films on the si(111) 7$\times$7 surface at various coverages.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.8-19
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• 2023

This paper presents advancement in multi- unmanned aerial vehicle (UAV) cooperative area surveillance, focusing on optimizing UAV route planning through the application of genetic algorithms. Addressing the complexities of comprehensive coverage, two real-time dynamic path planning methods are introduced, leveraging genetic algorithms to enhance surveillance efficiency while accounting for flight constraints. These methodologies adapt multi-UAV routes by encoding turning angles and employing coverage-driven fitness functions, facilitating real-time monitoring optimization. The paper introduces a novel path planning model for scenarios where UAVs navigate collaboratively without predetermined destinations during regional surveillance. Empirical evaluations confirm the effectiveness of the proposed methods, showcasing improved coverage and heightened efficiency in multi-UAV path planning. Furthermore, we introduce innovative optimization strategies, (Foresightedness and Multi-step) offering distinct trade-offs between solution quality and computational time. This research contributes innovative solutions to the intricate challenges of cooperative area surveillance, showcasing the transformative potential of genetic algorithms in multi-UAV technology. By enabling smarter route planning, these methods underscore the feasibility of more efficient, adaptable, and intelligent cooperative surveillance missions.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 하계종합학술대회 논문집
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• pp.397-400
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• 1999

As the result of enhancement of CAD, Design Automation and manufacturing technology, it's on the increasing complexity, integration ratio, data signals, and pin count to IC chips. This brings about difficulties of testing, and incresing test time. Now One of the most cost-consuming procedure as integration ratio increases is the testing step. In this paper, we propose a new method, “Efficient TP(test point) assignment algorithm” using “input grouping”, This is helpful method to reducing test length without losing fault coverage. Experimental results show that proposed method reduces test length remarkably and doesn't miss fault coverage, with low hardware overhead Increasing.

• 한국컴퓨터정보학회논문지
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• 제24권4호
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• pp.107-112
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• 2019

Failure testing is a test that verifies that the system is operating in accordance with failure response requirements. A typical failure test approaches the operating system by identifying and testing system problems caused by unexpected errors during the operational phase. In this paper, we study how to evaluate these Failure at the software development stage. Evaluate the probability of failure due to code changes through the complexity and duplication of the code, and evaluate the probability of failure due to exceptional situations with bugs and test coverage extracted from static analysis. This paper studies the possibility of failure based on the code quality of software development stage.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권6호
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• pp.2689-2708
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• 2016

Multi-camera systems which integrate two or more low-cost digital cameras are adopted to reach higher ground coverage and improve the base-height ratio in low altitude remote sensing. To guarantee accurate multi-camera integration, the geometric relationship among cameras must be determined through platform calibration techniques. This paper proposed a combined two-step platform calibration method. In the first step, the static platform calibration was conducted based on the stable relative orientation constraint and convergent conditions among cameras in static environments. In the second step, a dynamic platform self-calibration approach was proposed based on not only tie points but also straight lines in order to correct the small change of the relative relationship among cameras during dynamic flight. Experiments based on the proposed two-step platform calibration method were carried out with terrestrial and aerial images from a multi-camera system combined with four consumer-grade digital cameras onboard an unmanned aerial vehicle. The experimental results have shown that the proposed platform calibration approach is able to compensate the varied relative relationship during flight, acquiring the mosaicing accuracy of virtual images smaller than 0.5pixel. The proposed approach can be extended for calibrating other low-cost multi-camera system without rigorously mechanical structure.

• 한국진공학회지
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• 제2권2호
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• pp.161-165
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• 1993

Si(100)와 Si(111) 표면에 에피 성장시킨 Ge의 기하학적, 전기적 구조가 scanning tunneling microscope로 연구되었다. Ge 원자는 scanning tunneling spectroscopy와 bias 전압을 달리한 STM 상에서 Si 원자와 구별되었다. 이것을 이용하여 Ge의 성장 형태를 연구하였다. (2${\times}$1) 재배열 구조를 가진 (100) 표면에서 Ge 성장층은 720K에서 B형의 step edge로부터 주로 성장하였다. (111) 표면에서도 주로 step edge에서 성장하였으며, Ge의 양과 annealing 온도에 따라 (5${\times}$5)와 (7${\times}$7)구조가 보였다.

• 한국재료학회지
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• 제2권3호
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• pp.228-238
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• 1992

서브마이크론 설계규칙을 갖는 소자의 이층 배선 공정에서 다챔버 장비를 이용한 금속 층간절연막의 공극없는 평탄화를 위하여 PECVD와 $O_3$ ThCVD산화막의 증착시 층덮힘성을 연구하였다. 산화막의 두께가 증가됨에 따라 변화되는 순간단차비의 개념을 도입하여 공극형성의 개시점을 예측할 수 있는 관계식을 모델링하였고, 금속배선간격의 초기 단차비가 다양한 패턴에서 산화막의 두께에 따른 순간 단차비의 변화를 조사하였다. 모델링 검정결과 $5^{\circ}$이하의 re-entrant각을 갖는 TEOS에 의한 PECVO 산화막의 순간단차비가 모델링에 잘 일치하였다. 공극없는 평탄화는 제1층의 PECVD 산화막의 순간 단차비를 0.8이하로 유지하거나 Ar sputter식각을 통하여 산화막의 모서리에 경사를 준후 층덮힘성이 우수한 $O_3$ ThCVD산화막을 증착함으로써 가능하였다. $O_3$ ThCVD산화막의 etchback이 non etchback공정에 비하여 via접쪽저항체인에서 높은 수율을 보였으며, via접촉저항은 $0.1~0.3{\Omega}/{\mu}m^2$로 나타났다.

• 한국재료학회지
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• 제5권7호
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• pp.775-780
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• 1995

MOCVD(Metal-Organic Chemical Vapor Dposition) TiN 박막을 다양한 온도와 압력에서 tetrakis-dimethyl-amino-titanium(TDMAT (Ti[N($CH_3$)$_2$]$_4$))의 자체 열분해와 NH$_3$와의 반응을 사용하여 형성하였다. 비저항은 박막내의 불순물 함량에 의존하였는데 특히 XPS curve fitting 결과 주요 불순물인 탄소와 산소 같은 불순물들이 박막내에서 다양한 침입형화합물을 만들어 박막의 물리적, 전기적 특성에 영향을 준다는 것을 알았다. Metal-organic source만을 사용하여 TiN을 형성할 경우 지름이 0.5$\mu\textrm{m}$이고 aspect ratio가 3:1인 구멍에서 step coverage가 매우 우수하였으나 NH$_3$를 흘림에 따라 step coverage가 감소하는 것이 SEM으로 확인되었는데 이는 각각의 활성화에너지와 관련된 것으로 보인다.