• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.406-406
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• 2016

To get high efficiency n-type crystalline silicon solar cells, passivation is one of the key factor. Tunnel oxide (SiO2) reduce surface recombination as a passivation layer and it does not constrict the majority carrier flow. In this work, the passivation quality enhanced by different chemical solution such as HNO3, H2SO4:H2O2 and DI-water to make thin tunnel oxide layer on n-type crystalline silicon wafer and changes of characteristics by subsequent annealing process and firing process after phosphorus doped amorphous silicon (a-Si:H) deposition. The tunneling of carrier through oxide layer is checked through I-V measurement when the voltage is from -1 V to 1 V and interface state density also be calculated about $1{\times}1012cm-2eV-1$ using MIS (Metal-Insulator-Semiconductor) structure . Tunnel oxide produced by 68 wt% HNO3 for 5 min on $100^{\circ}C$, H2SO4:H2O2 for 5 min on $100^{\circ}C$ and DI-water for 60 min on $95^{\circ}C$. The oxide layer is measured thickness about 1.4~2.2 nm by spectral ellipsometry (SE) and properties as passivation layer by QSSPC (Quasi-Steady-state Photo Conductance). Tunnel oxide layer is capped with phosphorus doped amorphous silicon on both sides and additional annealing process improve lifetime from $3.25{\mu}s$ to $397{\mu}s$ and implied Voc from 544 mV to 690 mV after P-doped a-Si deposition, respectively. It will be expected that amorphous silicon is changed to poly silicon phase. Furthermore, lifetime and implied Voc were recovered by forming gas annealing (FGA) after firing process from $192{\mu}s$ to $786{\mu}s$. It is shown that the tunnel oxide layer is thermally stable.

• 한국전자통신학회논문지
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• 제15권1호
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• pp.107-114
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• 2020

본 논문에서는 하둡 플랫폼에서 비용 효율적 빅데이터 분석을 수행하기 위한 클러스터 규모의 설정 방안을 연구한다. 의료기관의 경우 진료기록의 병원 외부 저장이 가능해짐에 따라 클라우드 기반 빅데이터 분석 요구가 증가하고 있다. 본 논문에서는 대중적으로 많이 사용되고 있는 클라우드 서비스인 아마존 EMR 프레임워크를 분석하고, 비용 효율적으로 하둡을 운용하기 위해 클러스터의 규모를 산정하기 위한 모델을 제시한다. 그리고, 다양한 조건에서의 실험을 통해 맵리듀스의 실행에 영향을 미치는 요인을 분석한다. 이를 통해 비용 대비 처리시간이 가장 효율적인 클러스터를 설정함으로써 빅데이터 분석시 효율성을 증대시킬 수 있다.

• 한국전자통신학회논문지
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• 제9권8호
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• pp.847-852
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• 2014

반도체 소자 제조에서 비용 절감을 위한 공정기술의 스케일링 가속화 경향에 따라 축소기술에 대한 요구가 증가되고 있다. 축소에 따른 또 다른 가장 큰 문제점의 하나는 Hot Carrier Injection (HCI) 특성의 열화이다. 이는 축소 과정에서 생기는 불가피한 가장 큰 이슈중의 하나이며, 특히 입출력 소자에 있어 극복하기 어려운 부분이다. 이의 개선을 위해 유효 채널 길이를 늘이고자 LDD 임플란트 공정 이전에 산화막이 추가되었고, 또한 I/O LDD 임플란트 공정의 이온 입사 각도를 최적화함으로써, LDD 영역에서 E-field 열화 없이 HCI 규격을 만족할 수 있었다.

• Journal of Computing Science and Engineering
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• 제7권3호
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• pp.187-197
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• 2013

Security has long been a challenging problem in wireless networks, mainly due to its broadcast nature of communication. This opens up simple yet effective measures to thwart useful communications between legitimate radios. Spread spectrum technologies, such as direct sequence spread spectrum (DSSS), have been developed as effective countermeasures against, for example, jamming attacks. This paper surveys previous research on securing a DSSS channel even further, using physical layer attributes-keyless DSSS mechanisms, and watermarked DSSS (WDSSS) schemes. The former has been motivated by the fact that it is still an open question to establish and share the secret spread sequence between the transmitter and the receiver without being noticed by adversaries. The basic idea of the latter is to exploit the redundancy inherent in DSSS's spreading process to embed watermark information. It can be considered a counter measure (authentication) for an intelligent attacker who obtains the spread sequence to generate fake messages. This paper also presents and evaluates an adaptive DSSS scheme that takes both jam resistance and communication efficiency into account.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권8호
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• pp.2805-2826
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• 2021

In most cases, the routing policy of networks shows a preference for a static one-to-one mapping of communication pairs to routing paths, which offers adversaries a great advantage to conduct thorough reconnaissance and organize an effective attack in a stress-free manner. With the evolution of network intelligence, some flexible and adaptive routing policies have already proposed to intensify the network defender to turn the situation. Routing mutation is an effective strategy that can invalidate the unvarying nature of routing information that attackers have collected from exploiting the static configuration of the network. However, three constraints execute press on routing mutation deployment in practical: insufficient route mutation space, expensive control costs, and incompatibility. To enhance the availability of route mutation, we propose an OpenFlow-based route mutation technique called Polymorphic Path Transferring (PPT), which adopts a physical and virtual path segment mixed construction technique to enlarge the routing path space for elevating the security of communication. Based on the Markov Decision Process, with considering flows distribution in the network, the PPT adopts an evolution routing path scheduling algorithm with a segment path update strategy, which relieves the press on the overhead of control and incompatibility. Our analysis demonstrates that PPT can secure data delivery in the worst network environment while countering sophisticated attacks in an evasion-free manner (e.g., advanced persistent threat). Case study and experiment results show its effectiveness in proactively defending against targeted attacks and its advantage compared with previous route mutation methods.

• 한국전자통신학회논문지
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• 제14권4호
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• pp.781-786
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• 2019

오늘날 다양한 생명현상을 다루고있는 질병연구와 같은 효율적인 목적을 달성하기 위해서는 이들 연구로부터 획득한 빅데이터를 처리하여 효과적인 현실적 가치를 부여할 수 있어야 한다. 본 논문에서 제안한 MKSV알고리즘은 최적의 확률분포를 추정하여 입력패턴을 결정 한 후 데이터마이닝 기법으로 분류한 결과 효율적인 계산량과 인식률을 획득할 수 있었다. MKSV 알고리즘은 유전자 데이터의 확률적 흐름을 시뮬레이션하여 빅데이터의 데이터마이닝 과정을 통해 데이터를 분류하여 빠르고 효과적인 성능 향상을 보임으로써 현 사회에 급증하는 질병과 유전자의 관련성을 연구하는 데 유용할 것이다.

• 무역상무연구
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• 제38권
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• pp.3-45
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• 2008

A motive and aim of enactment of UN Convention on the Use of Electronic Communication in Int'l Contracts is based on need to eliminate legal obstacles that might arise under existing int'l trade law instruments and promote int'l electronic commercial transaction. But when it is used with related articles, 14, 15, 16, 17 for offer under CISG, one of the most successful conventions which produces substantive law for the unification of int'l trade, questions of practical importance, for example possibilities of withdrawal, revocation, rejection of offer, the extent of its criteria arise from therewith. In conclusion, a effective electronic offer has to assure easily access and confirmation of trade terms besides criteria of offer under CISG. An offer can be withdrawal, if electronic message of withdrawal has entered the offeree's server before or at the same time when the offer has reached the offeree but agreement expressly or impliedly, between the parties about type, format, email address is a prerequisited. Implied consent could be presumed through prior conduct or trade usages between the parties under CISG articles 8, 9. The term "have reached" correspond to the time which is able to retrieve the electronic message of withdrawal. But without express or implied agreement between them about electronic communication of type, format, email address, an offer can be withdrawal before or at the same time when it has entered offeree's other e-mail address and confirmed by his retrieval. In case of the revocation, electronic message of the revocation is effective before the offeree's dispatching an acceptance. A prerequisite for the revocation by electronic communication is came as the above mentioned withdrawal except for concept of a time difference for reach. In case of a rejection of offer, when a rejection by electronic communication has entered the offeror's server, an offer is ended. But a prerequisite for the rejection by electronic message is same as the above mentioned withdrawal and revocation.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 1998년도 추계학술대회 논문집
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• pp.114-117
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• 1998

Failure to link business or operations strategy with the activities of operations is a critical problem in strategy implementation process. This problem comes from malfunction of a coordination and control mechanism to support the strategic direction by effective communication throughout the firm. A performance measurement and evaluation system (PMES) is thought as a core mechanism to monitor, direct. and induce desirable activities. We have developed a new strategic PMES (SPMES) that can effectively support the manufacturing strategy by utilizing customized performance measures. They are selected from a pool of four distinct but closely related sets of performance measures; financial, market, internal competency, and performance driver. In this paper, we briefly review the structure of the SPMES and explain the change process of PMES into SPMES in manufacturing business units. First we analyze the business environment and manufacturing strategy to identify short- and long-term issues facing the management. Next step is scrutinizing the objectives and activities of every function and process in the business unit. Using the information obtained, we can diagnose the gaps between currently effective PMES and desirable SPMES supporting the strategies. Once the problems in existing system are identified, we reconfigure the existing and new measures to establish a SPMES through a series of analyses, discussions and workshops. In organizing the selected measures in the new system, we use AHP method to reflect the relative importance of the measures in a specific business. Finally, modification or development of information system to support the SPMES wraps up the development process, and implementation begins. We explain the entire process using two cases to clarify the real meanings and the difficulties of PMES change process.

• 한국전자통신학회논문지
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• 제9권10호
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• pp.1153-1159
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• 2014

본 논문은 항만 개발에서 일부분의 주민참여가 아닌 대부분의 주민들이 참여가 가능한 ICT(Information Communication Technology)과 소셜 네트워크 기술을 적용하여 동해시의 묵호항 재개발 사업 친수 시설 규모 산정방안에 대한 새로운 방법을 제시한다. 이를 위해 항만 재개발 과정에서 효과적인 주민참여를 위한 방법으로 기존의 단순한 설문조사 방식과 더불어 다양한 SNS(Social Network System)을 적용하여 주민들의 의견 최대화한 도시 마케팅 방안을 분석한다. 또한 이를 위해서 주민 참여에 대한 비율을 최적 선정을 수행하고 최적 건설비 산정과 도시 마케팅 방안을 제시한다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.630-633
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• 2003

Integrating the driver circuitry directly onto the glass substrate would be one of the advantages of polycrystalline Si (poly-Si) TFT-(LCD). Low-temperature poly-Si TFT(LTPS) is well-suited for higher-definition display applications due to its intrinsically superior electrical characteristics. In order to improve LTPS electrical characteristics, currently the excimer laser-induced crystallization (ELC) processes and sequential lateral solidification method were developed. Grain size of the poly-Si is mainly affected by beam pitch and energy density. Key parameter for making a larger poly-Si using excimer laser annealing(ELA) and increasing a throughput is due to increase in beam pitch and energy density to a certain degree. Furthermore, thin $SiO_{2}$ capping is effective to suppress the protrusion of the poly-Si thin films and to reduce the interface state density. From the ELA process, we are able to control grain size by varying different parameters such as number of shots and energy density.