• 제목/요약/키워드: two-step growth

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정보통신 표준화를 이용한 시장 전략과 이의 대응 방안

  • 김영태;박기식;한상욱;박명철
    • 기술경영경제학회:학술대회논문집
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    • 기술경영경제학회 1999년도 제16회 동계학술발표회 논문집
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    • pp.63-81
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    • 1999
  • The environment of Information and Telecommunication industry has rapidly changed. This is leading the growth of the world economy. Because of the characteristic of the information and communication, the standardization plays a important role in this market. The company that owns the standardization in its industry has dominant power like Microsoft in personal computer software, and Qualcomm in digital cellular phone system. Therefore, to take advantage of this standardization power, it is important to find which technology will be set up as a new standard. This paper presents how to capitalize the standardization as a market strategy. To perform this strategy, we take two steps. The first step is to strategically choose the most important technology or service which would lead the information and telecommunication market. We used modified AHP(Analytic Hierarchy Process) to set the priorities among the various standard related technologies and services, We interviewed with the information and telecommunication experts to find out some criteria and the weights of them. The second step is to select the standard to realize the technology. Actually, this is very hard to decide which technology we should select, because there are lots of alternative standards to develop the technology. In this step, we use a strategic framework for choosing the standard. This framework provides how the research institution and company do to get a maximum benefit from the standardization strategy, Finally, we applied these to Korea's situation simply in order to show how to take advantage of the framework.

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High Density Silver Nanowire Arrays using Self-ordered Anodic Aluminum Oxide(AAO) Membrane

  • Kim, Yong-Hyun;Han, Young-Hwan;Lee, Hyung-Jik;Lee, Hyung-Bock
    • 한국세라믹학회지
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    • 제45권4호
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    • pp.191-195
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    • 2008
  • Highly ordered silver nanowire with a diameter of 10 nm was arrayed by electroless deposition in a porous anodic aluminum oxide(AAO) membrane. The AAO membrane was fabricated electrochemically in an oxalic acid solution via a two-step anodization process, while growth of the silver nanowire was initiated by using electroless deposition at the long-range-ordered nanochannels of the AAO membrane followed by thermal reduction of a silver nitrate aqueous solution by increasing the temperature up to $350^{\circ}C$ for an hour. An additional electro-chemical procedure was applied after the two-step anodization to control the pore size and channel density of AAO, which enabled us to fabricate highly-ordered silver nanowire on a large scale. Electroless deposition of silver nitrate aqueous solution into the AAO membrane and thermal reduction of silver nanowires was performed by increasing the temperature up to $350^{\circ}C$ for 1 h. The morphologies of silver nanowires arrayed in the AAO membrane were investigated using SEM. The chemical composition and crystalline structure were confirmed by XRD and EDX. The electroless-deposited silver nanowires in AAO revealed a well-crystallized self-ordered array with a width of 10 nm.

(K0.5Na0.5)NbO3-CaZrO3 계에서 입자모양과 입자성장 거동 (Grain Shape and Grain Growth Behavior in the (K0.5Na0.5)NbO3-CaZrO3 System)

  • 이철이;문경석
    • 한국분말재료학회지
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    • 제29권2호
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    • pp.110-117
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    • 2022
  • The grain growth behavior in the (1-x)K0.5Na0.5NbO3-xCaZrO3 (KNNCZ-x) system is studied as a function of the amount of CZ and grain shape. The (1-x)K0.5Na0.5NbO3-xCaZrO3 (KNNCZ-x) powders are synthesized using a conventional solid-state reaction method. A single orthorhombic phase is observed at x = 0 - 0.03. However, rhombohedral and orthorhombic phases are observed at x = 0.05. The grain growth behavior changes from abnormal grain growth to the suppression of grain growth as the amount of CaZrO3 (CZ) increases. With increasing CZ content, grains become more faceted, and the step-free energy increases. Therefore, the critical growth driving force increases. The grain size distribution broadens with increasing sintering time in KNNCZ-0.05. As a result, some large grains with a driving force larger than the critical driving force for growth exhibit abnormal grain growth behavior during sintering. Therefore, CZ changes the grain growth behavior and microstructure of KNN. Grain growth at the faceted interface of the KNNCZ system occurs via two-dimensional nucleation and growth.

Time Evolution of a High-temperature GaN Epilayer Grown on a Low-temperature GaN Buffer Layer using a Low-pressure MOCVD

  • Chang, Kyung-Hwa;Cho, Sung-Il;Kwon, Myoung-Seok
    • Transactions on Electrical and Electronic Materials
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    • 제7권1호
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    • pp.36-41
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    • 2006
  • In this paper, the time evolution of undoped GaN epilayers on a low-temperature GaN buffer layer grown on c-plane sapphire at a low pressure of 300 Torr was studied via a two-step growth condition in a horizontal MOCVD reactor. As a function of the growth time at a high-temperature, the surface morphology, structural quality, and optical and electrical properties were investigated using atomic force microscopy, high-resolution x-ray diffraction, photoluminescence, and Hall effect measurement, respectively. The root-mean-square roughness showed a drastic decrease after a certain period of surface roughening probably due to the initial island growth. The surface morphology also showed the island coalescence and the subsequent suppression of three-dimensional island nucleation. The structural quality of the GaN epilayer was improved with increasing growth time considering the symmetrical (002) and asymmetrical (102) rocking curves. The variations of room-temperature photoluminescence, background carrier concentration, and Hall mobility were measured and discussed.

Impacts of Bank-Specific and Macroeconomic Risks on Growth and Stability of Islamic and Conventional Banks: An Empirical Analysis from Pakistan

  • REHMAN, Jamshid ur;RASHID, Abdul
    • The Journal of Asian Finance, Economics and Business
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    • 제9권2호
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    • pp.1-14
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    • 2022
  • The implications of bank-specific risks and macroeconomic risks on the growth, profitability, and stability of Islamic and conventional banks are examined and compared in this article. The study also investigates whether corporate governance mitigates the effects of both bank-specific and macroeconomic risks on Islamic and conventional banks' development, profitability, and stability. For the period 2007-2019, we examined a panel data set of 22 banks in Pakistan, including both Islamic and conventional banks. We discovered considerable evidence that both bank-specific risks and macroeconomic risks have negative effects on the growth, profitability, and stability of Pakistani banks using a dynamic panel data estimator, the two-step Generalized Method of Moments (GMM) approach. Furthermore, the findings show that bank-specific and macroeconomic risks have different consequences in both types of banking. The impacts of liquidity risk, operational risk, capital risk, inflation risk, and exchange rate risk are higher for Islamic banks than for conventional banks. Conventional banks, on the other hand, are more vulnerable to credit risk and interest rate risk. Finally, the findings show that good corporate governance reduces the negative consequences of both categories of risks on bank development, profitability, and stability. This is true for Islamic and conventional banks alike.

Excimer Laser응용 실리콘 결정화 공정에 대한 In-Situ 광학적 연구 (An In-Situ Optical Study on Silicon Crystallization Process Using an Excimer Laser)

  • 김우진;윤창환;박승호;김형준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1407-1411
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    • 2003
  • Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM analysis. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

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비정질 실리콘의 ELC 공정에 대한 광학적 연구 (An Optical Study on ELC Process of Amorphous Silicon)

  • 김우진;윤창환;박승호;김형준
    • 한국레이저가공학회지
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    • 제6권2호
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    • pp.9-17
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    • 2003
  • Due to the heat confinement in the shallow region of the target for a short time scale, pulsed laser annealing has received an increasing interest for the fabrication of poly-Si thin film transistors(TFTs) on glass as a low cost substrate in the flat panel displays. The formation and growth mechanisms of poly silicon(poly-Si) grains in thin films are investigated using an excimer laser crystallization system. To understand the crystallization mechanism, the grain formations are observed by FESEM photography. The optical reflectance and transmittance during the crystallization process are measured using HeNe laser optics. A two-step ELC(Excimer Laser Crystallization) process is applied to enhance the grain formation uniformity.

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EFFECT OF SUBSTRATE BIAS ON THE DIAMOND GROWTH USING MICROWAVE PLASMA CVD

  • Sakamoto, Yukihiro;Takaya, Matsufumi
    • 한국표면공학회지
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    • 제32권3호
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    • pp.303-306
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    • 1999
  • On the effect of substrate bias at first stage of diamond synthesis at lower substrate temperature(approximately 673K) using microwave plasma CVD and effect of reaction gas system for the bias enhanced nucleation were studied. The reaction gas was mixture of methane and hydrogen or carbon monoxide and hydrogen. The nucleation density of applied bias -150V using $CH_4-H_2$ reaction gas system, significantly higher than that of $C-H_2$ reaction gas system. When the $CH_4-H_2$ reaction was used, nucleation density was increased because of existence of SiC as a interface for diamond nucleation. By use of this negative bias effect for fabrication of CVD diamond film using two-step diamond growth without pre-treatment, fabrication of the diamond film consist of diamond grains $0.2\mu\textrm{m}$ in diameter was demonstrated

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의미 정보를 이용한 이단계 단문분할 (Two-Level Clausal Segmentation using Sense Information)

  • 박현재;우요섭
    • 한국정보처리학회논문지
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    • 제7권9호
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    • pp.2876-2884
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    • 2000
  • 단문분할은 한 문장에 용언이 복수개 있을 때 용언을 중심으로 문장을 나누는 방법이다. 기존의 방법은 정형화된 문장의 경우 비교적 효율적인 결과를 얻을 수 있으나, 구문적으로 복잡한 문장인 경우는 한계를 보였다. 본 논문에서는 이러한 한계를 극복하기 위해서 구문 정보만이 아니라, 의미 정보를 활용하여 단문을 분할하는 방법을 제안한다. 정형화된 문장의 경우와 달리 일상적인 문장은 무장 구조의 모호성이나 조사의 생략 등이 빈번하므로 의미 수준에서의 단문분할이 필요하다. 의미 영역에서 단문분할을 하면 기존의 구문 의존적인 방법들에서 발생하는 모호성을 상당수 해소할 수 있게 된다. 논문에서는 먼저 하위범주와 사전과 시소러스의 의미 정보를 이용하여 용언과 보어성분 간의 의존구조를 우선적으로 파악하고, 구문적인 정보와 기타 문법적인 지식을 사용하여 기타 성분을 의존구조에 점진적으로 포함시켜가는 이단계 단문분할 알고리즘을 제안한다. 제안된 이단계 단문분할 방법의 유용성을 보이기 위해 ETRI-KONAN의 말뭉치 중 25,000문장을 수작업으로 술어와 보어성분 간의 의존구조를 태깅한 후 본 논문에서 제안한 방법과 비교하는 실험을 수행하였으며, 이때 단문분할의 결과는 91.8%의 정확성을 보였다.

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Multivesicular Liposomes for Oral Delivery of Recombinant Human Epidermal Growth Factor

  • Li Hong;An Jun Hee;Park Jeong-Sook;Han Kun
    • Archives of Pharmacal Research
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    • 제28권8호
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    • pp.988-994
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    • 2005
  • The purpose of the present study was to prepare multivesicular liposomes with a high drug loading capacity and to investigate its potential applicability in the oral delivery of a peptide, human epidermal growth factor (rhEGF). The multivesicular liposomes containing rhEGF was prepared by a two-step water-in-oil-in-water double emulsification process. The loading efficiency was increased as rhEGF concentration increased from 1 to 5mg/mL, reaching approximately $60\%$ at 5 mg/mL. Approximately $47\%$ and $35\%$ of rhEGF was released from the multivesicular liposomes within 6 h in simulated intra-gastric fluid (pH 1.2) and intra-intestinal fluid (pH 7.4), respectively. rhEGF-loaded multivesicular liposomes markedly suppressed the enzymatic degradation of the peptide in an incubation with the Caco-2 cell homogenate. However, the transport of rhEGF from the multivesicular liposomes to the basolateral side of Caco­2 cells was two times lower than that of the rhEGF in aqueous solution. The gastric ulcer healing effect of rhEGF-loaded multivesicular liposomes was significantly enhanced compared with that of rhEGF in aqueous solution; the healing effect of the liposomes was comparable to that of the cimetidine in rats. Collectively, these results indicate that rhEGF-loaded multivesicular liposomes may be used as a new strategy for the development of an oral delivery system in the treatment of peptic ulcer diseases.