• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.6
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• pp.293-297
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• 2005

Linearity is an important property of optical devices for analog communications. In this paper, we study the 3rd-order interrnodulation distortion (IMD3) of an Inp/InGaAsP multiple-quantum-well (MQW) traveling-wave type electroabsorption modulator (TW-EAM). We observe abnormal notches in the IMD3 results those were different from notches by general transfer curve of electroabsorption modulators (EAMs). We analyze the phenomena through absorption coefficients according to wavelengths and bias voltages to verify appearance of the abnormal notchs, where it can be known to result from Stark-shift and broadening. We propose the method to enhance linearity of MQW-EAMs by using these effects.

• Journal of the Optical Society of Korea
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• v.11 no.3
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• pp.133-137
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• 2007

We compare electroabsorption modulators (EAMs) with multiple quantum wells (MQWs) based on InGaAs(P)/InP and InGa(Al)As/InAlAs material systems. We carefully choose the quantum-well structures so that the structures based on different material systems have similar band-offset energies and excition-peak wavelengths. Assuming the same light wavelength of $1.55{\mu}m$, we show the transfer functions of EAMs with each quantum-well structure and calculate the escape times of photogenerated charge carriers. As the heavy-hole escape time of the quantum well based on InGaAs(P)/InP is much longer than those of photogenerated charge carriers of InGa(Al)As/InAlAs, the EAM based on the InGa(Al)As/InAlAs material seems to be more suitable for high-optical-power operation.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.5
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• pp.1-9
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• 2021

In Korea, various information related to COVID-19 has been provided to the public through an EAM (Emergency Alert Message) service using CBS (Cell Broadcast Service) technology to respond to COVID-19. In particular, local governments have been actively using the EAM service as a major means of responding to COVID-19. However, since excessive use of EAM service has caused the inconvenience of the people rather than the positive effects, the authority to be able to send EAMs has be limited. In this paper, with the purpose of providing primary data for establishing a plan to properly operate EAMs, we compare and analyze the number of EAMs issued and the incidence rate of COVID-19 cases during the period from 2020 to the present. In addition, the monthly EAM usage and incidence rate of COVID-19 cases are compared in detail and correlation analysis is performed for local governments that have issued many EAMs. We expect that the analysis results of this paper will be used as primary data in establishing strategies for EAM service to counteract the prolonged COVID-19.

• ETRI Journal
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• v.28 no.4
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• pp.533-536
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• 2006

A distributed Bragg reflector (DBR) laser and a high speed electroabsorption modulator (EAM) are integrated on the basis of the selective area growth technique. The typical threshold current is 4 to 6 mA, and the side mode suppression ratio is over 40 dB with single mode operation at 1550 nm. The DBR laser exhibits 2.5 to 3.3 mW fiber output power at a laser gain current of 100 mA, and a modulator bias voltage of 0 V. The 3 dB bandwidth is 13 GHz. A 10 Gbps non-return to zero operation with 12 dB extinction ratio is obtained. A four-channel laser array with 100 GHz wavelength spacing was fabricated and its operation at the designed wavelength was confirmed.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.11a
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• pp.455-458
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• 2008

기업의 전사적 비즈니스와 IT 환경의 통합 청사진을 보여주는 엔터프라이즈 아키텍처의 효율적인 시스템 적용을 위하여는 조직의 비즈니스, 정보, 응용시스템, 기술 기반구조의 연관관계와 미래모델을 시각적으로 사용자에게 보여주어야 한다. 기존 ITAMS 혹은 EAMS 라고 불리는 시스템에 아키텍처 툴을 이용하여 EA 의 모델정보를 퍼블리싱하여 시각화하였는데 시스템과 아키텍처 툴간의 플랫폼의 이질성으로 인하여 아키텍처정보를 그래픽화하여 변환하고 해당정보를 시스템에서 보여주는데 실시간 적용이 불가능 했을 뿐 아니라 사용자의 편의성이 원활하지 않았다. 이에 본 연구는 XML 기반의 SVG 그래픽 도구를 이용하여 아키텍처 작업을 가능하게 하고 SVG 정보의 자동 생성 및 웹기반 모델링 툴을 구현하여 시스템과 모델링 툴의 단일 레파지토리화를 통하여 데이터의 이원화를 해소하고 사용자 편의성을 증대하는 패턴을 구현한다.

• The KIPS Transactions:PartD
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• v.12D no.6 s.102
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• pp.857-862
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• 2005

MND(Ministry of National Defense) has developed MND AF(Ministry of National Defense Architecture Framework) and CADM(Core Architecture Data Model to guarantee interoperability among defense information systems. But, it is very difficult to manage architecture product documented through MND AF and CADM. So, there Is necessity for development of modeling tool and repository system which can develop architecture products and manage architecture product informations in common repository In this paper, we developed architecture product management system which supports development and management of meta model and architecture product of MND AF and CADM. Through architecture product management system architect of each agency can construct architecture product in a more effective and efficient way with modeling method and a user can search and refer useful architecture product informations using query function. Also, architecture product management system provides the basis for system integration and interoperability with integration, analysis and comparison of architecture product.

• Magazine of the Korea Concrete Institute
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• v.6 no.2
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• pp.180-187
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• 1994

Sixteen reinforced concrete beams were tested statically up to failure to investigate the arch action. Major variables were the shear span to depth ratio, steel ratio and existence of stirrups.The arch action in reinforced concrete beams started when flexural cracks appeared at the center of the span. Due to the reduction of internal moment arm length by the development of arch action, the measured steel tension was significantly higher than the calculated. As the shear span to depth ratio arid steel ratio decrease, the arch action in reinforced concrete eams increases. Over the entire length the force in the steel of no web reinforced beams having smaller a /d ratio than 3 was constant because the beams acted as a tied arch.

• Journal of Information Technology and Architecture
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• v.11 no.4
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• pp.409-426
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• 2014

Korea has won 3 times in a row in the evaluation of e-government services in 2014. And the last year, the government-EA has been awarded the UN Public Service Award. Because of the development and execution of personalized integrated services based on the government-EA, Korea has won the two award from the UN. EA has been selected and proceeded as one of the 31 e-Government projects in early period, in 2005 the law which public sector must adopt the EA for efficient informatization had been enacted. Many public agencies in which actively utilized to derive such as internal and external performance through the EA. On the other hand, in the last 10 years, some public agencies have still been as recognized level of management in the EA. In this study, the main purpose is that to find out what is a major factor for successful use and result of EA, what is the EA success Model and how to examine it. To do that, this study will study the related prior research such as EA services, information systems success factors, performance measures, and develop the success model for EA and then examine the model. This study will contribute great implications in practical and theoretical in EA success model because this is the nation's first research that SERVQUAL model and the IS Success Model(DeLone & McLean 2003) has been combined and examined.

• Resources Recycling
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• v.6 no.3
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• pp.3-8
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• 1997

The EA.F. sleelmaking slag (slag that follow) of a cnmvany 1 Co.. containzd a simple substance of a metal, wustlte (FeO), magnetite (Fe,O,), gehlenite (CaAl,SiO,), monlicellite (CaMgSiO,), dc. To recovere a metal (Fe grade . t95%) in the slag, it is desirable that the particles of a metal are isolated from thc slag and madc for a liberated subslance. Then, the liberaled melal is easlly recoveled by a magnetic separation. If thc rcclarnalcd slag, the sizc of which ranges under 40 nun, have a mulli-stage crushing, the most of a metal in thc slag is simply isolaled as a liberated subslance. If the mad, lhat is a liberated subslance and a sphere, is recovered by a magnetic field intensity. the minimum intensity, at which a metal is attracted, is approximately IOOG and did no1 dcpcnd on the particle size of a metad in the same particles. TIe recovered material. that contdined a iron (Fe) over 95% is a metal which is crushed slag by l00G in the multi-stage. If the magnetic field intcns~ty increase, the recovery mcrcasc, but the concentration grade decrease Bewusc thc concentration eams more and more impurities, iron oxide and the coml~ound of alkali earth element. 'll~ercforc If the rccla~nated slag have the multi-stage crushing, the metal is almostly recovered in the crushed slag by lO0G on each particles. If the slag, used as a rcclamatian lhat is a amount of 350,000 tan from I Co., was undcr the multistage crushing and then separaled by 100gauss, it is possible to recova a metal approximately 2.500 Ion, lhat is 0.73% of n ~eclamated slag. in 304.7 mm particles and to recover 4.200 tan in 0.3-1.7 mm particles , that is 1.2% nf a rcclamated slag, in a year. Therefore, ihe told recoverable meld is 6,700 ton, that is 19% of a reclmated slag, in a year, too.