• 상하수도학회지
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• 제26권1호
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• pp.131-139
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• 2012

Field experiment was performed from June 2010 to July 2011 to evaluate pollutants removal efficiency in the constructed wetland system for the treated wastewater and the river water. The wetland systems were constructed near Gyungan river. Two different systems with meandering shape were compared for seasonal base and operational period base. Several kinds of aquaculture are planted through the corridor of wetland system. Average removal rate of BOD, T-N and T-P for A system were 15.8%, 14.8% and 26.5%, respectively. Average removal rate of BOD, T-N and T-P for C system were 23.5%, 27.8% and 10.6%, respectively. The effluent from two wetland systems often exceeded effluent water quality standards for wastewater influent, however effluent water quality standards for river water. However, the wetland system can be useful to treat polluted river water and effluent from wastewater plant. Removal rate of pollutants in seasonal variation was the highest in summer for BOD and T-N, however the removal rates of T-P were higher in spring and autumn than in summer.

• 대한교통학회지
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• 제23권1호
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• pp.45-54
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• 2005

본 연구의 목적은 국제공항의 주요 서비스 항목별 중요도(importance), 이용자의 지각수준(perceived level), 다양한 평가방법(complex index)등을 활용한 주관적 및 객관적 측정 척도를 개발하고자 하며 공항서비스 질에 대한 기준 설정, 주요개선 사항의 발견 및 조치평가 등을 체계적으로 할 수 있는 내부관리용 옴니버스 모니터링 시스템 (OMS : Omnibus Monitoring System)의 개발이다. 이는 국제공항의 주요 서비스 평가를 위한 계량적 분석 도구의 개발과 2차 계량 지료(quantitative Secondary data)활용, 공항이용자에 대한 설문으로 지각된 자료(perceived data)분석, 자료수집-입력-분석 과정의 시스템화, 결과물의 그래픽화에 따른 데이터이미지화, 서비스인카운터(service encounter)계획 및 통제 기능 부여, 국제적 기준을 최저로 경쟁력을 확보하려는 것이다. 또한, 지표의 개발을 위해서 기존의 외국문헌 및 국제공항의 실사에 기초한 사전조사 계획의 수립과 실행이 중요하기에 준비된 사전조사의 결과를 토대로 출국자, 입국자, 상주근문자 등의 주관적 측정정도를 개발하고 보완적인 수단으로써 객관적 지표의 연구가 동시에 이루어졌다. 이러한 절차로 개발된 평가척도의 신뢰성 및 타당성을 실증적, 통계적으로 확보하고, 공항 서비스 척도의 효율적인 운영을 위한 소프트웨어 시스템을 개발함으로써 정규, 비정규적인 공항서비스의 모니터링이 가능하도록 연구가 진행되었다.

• Progress in Superconductivity
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• 제12권2호
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• pp.114-117
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• 2011

We report our efforts on the development of Nb-based non-hysteretic Josephson junction fabrication process for quantu device applications. By adopting and modifying the existing Nb-aluminum oxide tunnel junction process, we develop a process for non-hysteretic Josephson junction circuits using metal-silicide as metallic barrier material. We use sputter deposition of Nb and $MoSi_2$, PECVD deposition of silicon oxide as insulator material, and ICP-RIE for metal and oxide etch. The advantage of the metal-silicide barrier in the Nb junction process is that it can be etched in $SF_6$ RIE together with Nb electrode. In order to define a junction area precisely and uniformly, end-point detection for the RIE process is critical. In this paper, we employed thin Al layer for the etch stop, and optimized the etch condition. We have successfully demonstrated that the etch stop properties of the inserted Al layer give a uniform etch profile and a precise thickness control of the base electrode in Nb trilayer junctions.

• 대한디지털의료영상학회논문지
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• 제11권2호
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• pp.69-77
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• 2009

This study gives an account of the collateral standards in IEC 60601-1-3: 2008 specifying the general requirements for basic safety and essential performance of diagnostic X-ray equipment regarding radiation protection as it pertains to the production of X-rays. The collateral standards establish general requirements for safety regarding ionization radiation in diagnostic radiation systems and describe a verifiable evaluation method of suitable requirements regarding control over the lowest possible dose equivalent for patients, radiologic technologists, and others. The particular standards for each equipment can be determined by the general requirements in the collateral standard and the particular standard is followed in the risk management file. The guidelines for radiation safety of diagnostic radiation systems is written up in ISO 13485, ISO 14971, IEC 60601-1-3(2002)1st edition, medical electric equipment part 1-3, and the general requirements for safety-collateral standards: programmable electrical medical systems. Therefore the diagnostic radiation system protects citizens' health rights with the establishment and revisions of laws and standards for diagnostic radiation systems as a background for the general requirements of radiation safe guards applies, as an international trend, standards regarding the medical radiation safety management. The diagnostic radiation system will also assure competitive power through a conforming evaluation unifying the differing standards, technical specifications, and recognized processes.

• 국제초고층학회논문집
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• 제2권3호
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• pp.257-269
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• 2013

This study presents the development of an advanced multiple database-enabled design module for high-rise buildings (DEDM-HR), which seamlessly pools databases of multiple high frequency base balance measurements from geographically dispersed locations and merges them together to expand the number of available building configurations for the preliminary design. This feature offers a new direction for the research and professional communities that can be utilized to efficiently pool multiple databases therefore expanding the capability of an individual database and improving the reliability of design estimates. This is demonstrated, in this study, by the unprecedented fusion of two major established databases, which facilitates interoperability. The DEDM-HR employs a cyberbased on-line framework designed with user-friendly/intuitive web interfaces for the convenient estimation of wind-induced responses in the alongwind, acrosswind and torsional directions with minimal user input. In addition, the DEDM-HR embeds a novel feature that allows the use of wind characteristics defined in a code/standard to be used in conjunction with the database. This supplements the provisions of a specific code/standard as in many cases guidance on the acrosswind and torsional response estimates is lacking. Through an example, results from several international codes and standards and the DEDM-HR with the embedded features are compared. This provision enhances the scope of the DEDM-HR in providing an alternative design tool with nested general provisions of various international codes and standards.

• 열처리공학회지
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• 제8권3호
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• pp.205-212
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• 1995

Effect of Mn addition on rolling contact fatigue of C-base induction hardened bearing steels has been investigated to develop inexpensive surface-hardened bearing steels with improved resistance to rolling contact fatigue. Fatigue tests were conducted in elasto-hydrodynamic lubricating conditions at a shaft speed of 5,000rpm, under max. Hertzian stress of $492kg/mm^2$. It was found in the C-Mn steels that effective depth of induction hardened layer and amount of retained austenite were slightly increased in comparison with those of C-base steels. finer interlamellar spacing of pearlite in the C-Mn steels was also observed using TEM. Decomposition of retained austenite during rolling contact fatigue was smaller in quantity in the C-Mn steels than C-base steels. This might be associated with enhanced mechanical stability of retained austenite with addition of Mn. Statistical analysis of fatigue life for C-Mn steels using Weibull distribution indicated that improved resistance to rolling contact fatigue was mainly attributed to transformation induced plasticity and mechanical stability of retained austenite.

• Smart Structures and Systems
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• 제15권6호
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• pp.1439-1461
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• 2015

Design criteria, modeling rules, and analysis principles of seismic isolation systems have already found place in important building codes and standards such as the Uniform Building Code and ASCE/SEI 7-05. Although real behaviors of isolation systems composed of high damping or lead rubber bearings are nonlinear, equivalent linear models can be obtained using effective stiffness and damping which makes use of linear seismic analysis methods for seismic-isolated buildings possible. However, equivalent linear modeling and analysis may lead to errors in seismic response terms of multi-story buildings and thus need to be assessed comprehensively. This study investigates the accuracy of equivalent linear modeling via numerical experiments conducted on generic five-story three dimensional seismic-isolated buildings. A wide range of nonlinear isolation systems with different characteristics and their equivalent linear counterparts are subjected to historical earthquakes and isolation system displacements, top floor accelerations, story drifts, base shears, and torsional base moments are compared. Relations between the accuracy of the estimates of peak structural responses from equivalent linear models and typical characteristics of nonlinear isolation systems including effective period, rigid-body mode period, effective viscous damping ratio, and post-yield to pre-yield stiffness ratio are established. Influence of biaxial interaction and plan eccentricity are also examined.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.763-766
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• 2006

만화가 예술장르의 하나로써 회자되는 것을 발견하기란 어렵지 않다. 그런데도 여전히 예술 전반에 관한 논의에서 만화는 제외되는 일이 흔한 것은, 만화의 예술적 가치를 규명하고 알리기 위한 노력이 그 효과를 보이지 못하고 있기 때문인 듯싶다. 어떤 예술장르의 가치를 밝혀내어 알리고 그 위상을 굳건히 다지게끔 하는 일은 비평의 몫이다[l]. 그러나 만화비평은 그와 같은 기능을 위한 뚜렷한 준거가 마련되지 않은 바, 그러므로 본고에서는 만화비평이 만화의 예술적 가치를 판단하고 제시하기 위해 어떠한 준거를 가져야 하는지를 논하고자 한다. 이를 위해 모든 예술의 보편 타당한 가치를 밝히고자 시도했던 예술이론들을 대상으로 논의를 진행하여 각 예술이론들로부터 도출 가능한 준거들을 살펴보고, 그들이 만화에 대해 구체적으로 제시할 수 있는 준거에 대해 살펴본다.

• Progress in Superconductivity
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• 제9권1호
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• pp.50-55
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• 2007

We have installed a 61-channel magnetocardiography (MCG) system inside a magnetically shielded room (MSR) with a size of $2.4\;m\;{\times}2.4\;m\;{\times}2.4\;m$. The MCG system consists of 1st-order axial gradiometers containing double relaxation oscillation SQUIDs (DROSs) with pick-up coils of a base line of 70 mm. The MSR holds a shielding factor of 50 at 0.1 Hz and 10000 at 100 Hz, when its door in the middle on a front wall is closed. On opening the MSR door, we have obtained the characteristics of the MCG system with a 2.9 Hz noise generated from an air conditioning unit at 13 m distance off the MSR. In an open-door MSR ($140^{\circ}$ opening), a noise at the center channel increases up to $700\;fT/Hz^{l/2}$ at 2.9 Hz and $1.7\;pT/Hz^{1/2}$ at 60 Hz. MCG signals for a healthy human do not show distortion until the door opens to $45^{\circ}$, but show the effect of noise when the door opens further at $90^{\circ}$ and $140^{\circ}$. With the door opens to $45^{\circ}$, MCG measurement can be performed with ease of door operation and without creating claustrophobia for the patient.

• 한국진공학회지
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• 제18권6호
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• pp.411-417
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• 2009

차세대 반도체 및 디스플레이 산업용 드라이펌프의 배기속도를 평가하기 위해 최소부피 22 L 급의 정적형 유량계를 설계/제작 하였다. 정적형 유량계의 기본 평가항목인 base pressure와 leak rate 측정결과 각각 $6{\times}10^{-8}\;mbar$ 와 $1.5{\times}10^{-6}\;mbar-L/s$로 측정되었고 throughput limit의 경우 기존 875 L 급보다 1 order 낮은 $1{\times}10^{-3}\;mbar-L/s$ 영역까지 확대되었음이 확인되었다. 구축된 시스템을 이용해 배기용량이 적은 최신 공정 드라이 펌프까지도 배기속도 값을 정확히 측정할 수 있으며, 구축비용이 높은 정압형 유량계를 어느 정도 대체할 수 있을 것으로 기대하고 있다.