• 한국진공학회지
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• 제15권6호
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• pp.581-586
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• 2006

차세대 리소그래피 기술인 극자외선(EUV : Extreme Ultraviolet) 빛샘 연구의 기초단계로써, 동축타입의 전극구조가 설치된 다이오드 챔버를 통해 Ar 플라스마를 생성하였으며, 방출 분광기술(emission spectroscopy)를 이용하여 방출된 가시광선 영역의 빛을 조사하였다. 장치의 입력 전압을 0.5kV씩 변화를 주어 $2\sim3.5kV$까지 인가를 했으며 이극챔버의 최적 압력인 330mTorr 일 때 각 전압에 따른 방출 분광선 데이터를 얻었다. 이때 Ar I과 Ar II 방출선을 관측하였으며 국소적인 열적평형 (LTE ; Local Thermodynamic Equilibrium) 상태의 가정 하에 볼츠만 도표(Boltzmann plot)와 사하(Saha) 방정식을 이용해 Ar I 및 Ar II의 전자온도와 이온 밀도를 각각 계산하였다. 각 입력전압에 대해 이온밀도는 Ar I과 Ar II에서 각각 $\sim10^{15}/cc$ 및 $\sim10^{13}/cc$의 값으로 계산되었다.

• 보존과학회지
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• 제38권2호
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• pp.144-153
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• 2022

국방부 유해발굴단을 통해 발굴된 지역 유품 중 지상작전 사령부 전시관에 소장된 7건(정화제병, 독수리문양 단추, 계급장, 반합, M1 Grand-총기손질도구, 카빈완탄, 탄통)의 6·25 전사자 유품에 대하여 과학적 분석 및 보존처리를 진행하였다. FT-IR 분석 결과 정화제병 내부 잔존물이 Trisodium phosphate와 유사 스펙트럼으로 확인되어 전쟁 시 식수 및 식품 정화제로서의 역할을 수행하였음을 추정할 수 있었으며, 3차원 디지털 촬영기법을 통해 육안으로 관찰이 어려운 탄통의 각인된 명문을 확인하였다. 또한 현미경 및 육안 관찰 등을 기초로 한 상태조사를 진행하여 각각의 유품에 대한 보존처리 방향성을 수립하고 안정적인 처리를 진행할 수 있었다. 이러한 결과는 향후 다양한 전쟁 유품에 대한 보존처리 방향성 정립을 위한 기초자료로 활용될 수 있을 것이다.

• Structural Engineering and Mechanics
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• 제14권3호
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• pp.287-306
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• 2002

The assessment of structural performance of transfer structures under potential seismic actions is presented. Various seismic assessment methodologies are used, with particular emphasis on the accurate modelling of the higher mode effects and the potential development of a soft storey effect in the mega-columns below the transfer plate (TP) level. Those methods include response spectrum analysis (RSA), manual calculation, pushover analysis (POA) and equivalent static load analysis (ESA). The capabilities and limitations of each method are highlighted. The paper aims, firstly, to determine the appropriate seismic assessment methodology for transfer structures using these different approaches, all of which can be undertaken with the resources generally available in a design office. Secondly, the paper highlights and discusses factors influencing the response behaviour of transfer structures, and finally provides a general indication of their seismic vulnerability. The representative Hong Kong building considered in this paper utilises a structural system with coupled shear walls and moment resisting portal-frames, above and below the TP, respectively. By adopting the wind load profile stipulated in the Code of Practice on Wind Effects: Hong Kong-1983, all the structural members are sized and detailed according to the British Standards BS8110 and the current local practices. The seismic displacement demand for the structure, when built on either rock or deep soil sites, was determined in a companion paper. The lateral load-displacement characteristic of the building, determined herein from manual calculation, has indicated that the poor ductility (brittle nature) of the mega-columns, due mainly to the high level of axial pre-compression as found from the analysis, cannot be effectively alleviated solely by increasing the quantity of confinement stirrups. The interstorey drift demands at lower and upper zones caused by seismic actions are found to be substantially higher than those arising from wind loads. The mega-columns supporting the TP and the coupling beams at higher zones are identified to be the most vulnerable components under seismic actions.

• Progress in Superconductivity
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• 제14권2호
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• pp.99-101
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• 2012

Fluorescent yield X-ray absorption fine structure (XAFS) spectroscopy is useful for analyzing local structure of specific elements in matrices. We developed an XAFS apparatus with a 100-pixel superconducting tunnel junction (STJ) detector array with a high sensitivity and a high resolution for light-element dopants in wide-gap semiconductors. An STJ detector has a pixel size of $100{\mu}m$ square, and an asymmetric layer structure of Nb(300 nm)-Al(70 nm)/AlOx/Al(70 nm)-Nb(50 nm). The 100-pixel STJ array has an effective area of $1mm^2$. The XAFS apparatus with the STJ array detector was installed in BL-11A of High Energy Accelerator Research Organization, Photon Factory (KEK PF). Fluorescent X-ray spectrum for boron nitride showed that the average energy resolution of the 100-pixels is 12 eV in full width half maximum for the N-K line, and The C-K and N-K lines are separated without peak tail overlap. We analyzed the N dopant atoms implanted into 4H-SiC substrates at a dose of 300 ppm in a 200 nm-thick surface layer. From a comparison between measured X-ray Absorption Near Edge Structure (XANES) spectra and ab initio FEFF calculations, it has been revealed that the N atoms substitute for the C site of the SiC lattice.

• 한국지진공학회논문집
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• 제13권5호
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• pp.23-29
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• 2009

1996년 12월 13일 강원도 영월군 지역에서 국지규모(M$_L$) 4.5의 지진이 발생하였다. 진앙은 37.2545$^{\circ}$N, 128.7277$^{\circ}$E이며, 지체구조구상 옥천습곡대에 해당한다. 지진자료의 필터링 대역에 따라 파형역산을 수행하였는데, 0.02$\sim$0.2 Hz 필터링 대역을 적용할 경우 진원 깊이는 6 km, 지진모멘트는 1.3$\times$10$^{16}$ N$\cdot$m로 추정되었다. 이 지진모멘트는 모멘트규모(M$_W$) 4.7에 해당한다. 파형역산과 P파의 초동 극성 분석을 통한 영월 지진의 발진기구는 역단층 성분을 포함한 주향이동단층 특성을 보이며, 주응력 방향은 동북동-서남서 방향이다. 스펙트럼 분석을 통해 추정된 모멘트규모는 4.8이며, 이는 파형역산에 의해 추정된 모멘트규모와 비슷하다. 평균 응력강하는 14.3 MPa로 추정되었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.76.1-76.1
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• 2015

Optical resonances of metallic or dielectric nanoantennas enable to effectively convert free-propagating electromagnetic waves to localized electromagnetic fields and vice versa. Plasmonic resonances of metal nanoantennas extremely modify the local density of optical states beyond the optical diffraction limit and thus facilitate highly-efficient light-emitting, nonlinear signal conversion, photovoltaics, and optical trapping. The leaky-mode resonances, or termed Mie resonances, allow dielectric nanoantennas to have a compact size even less than the wavelength scale. The dielectric nanoantennas exhibiting low optical losses and supporting both electric and magnetic resonances provide an alternative to their metallic counterparts. To extend the utility of metal and dielectric nanoantennas in further applications, e.g. metasurfaces and metamaterials, it is required to understand and engineer their scattering characteristics. At first, we characterize resonant plasmonic antenna radiations of a single-crystalline Ag nanowire over a wide spectral range from visible to near infrared regions. Dark-field optical microscope and direct far-field scanning measurements successfully identify the FP resonances and mode matching conditions of the antenna radiation, and reveal the mutual relation between the SPP dispersion and the far-field antenna radiation. Secondly, we perform a systematical study on resonant scattering properties of high-refractive-index dielectric nanoantennas. In this research, we examined Si nanoblock and electron-beam induced deposition (EBID) carbonaceous nanorod structures. Scattering spectra of the transverse-electric (TE) and transverse-magnetic (TM) leaky-mode resonances are measured by dark-field microscope spectroscopy. The leaky-mode resonances result a large scattering cross section approaching the theoretical single-channel scattering limit, and their wide tuning ranges enable vivid structural color generation over the full visible spectrum range from blue to green, yellow, and red. In particular, the lowest-order TM01 mode overcomes the diffraction limit. The finite-difference time-domain method and modal dispersion model successfully reproduce the experimental results.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.369-375
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• 2001

For Optimization technology Was Developed in 1960, the Optimization Technology have grown into a full-featured, robust, highly rated and highly used. And Optimization techniques, having reached a degree of maturity over the past several years, are being used in a wide spectrum of industries, including aerospace, automotive, chemical, electrical, and manufacturing industries. With rapidly advancing computer technology, computers are becoming more powerful, and correspondingly, the size and the complexity of the problems being solved using Optimization techniques are also increasing. But Optimization techniques with analysis solver have many problems. For instance, the difficulties that a particular interface must be coded for each design problem and that the designer should be familiar with the optimization program as well as the analysis program. The purpose of this paper is Optimal Design Framework for Mechanical systems design. This Design Framework has two Optimizers, ADS (local optimizer) and RSM(Response Surface Method), and graphic user interfaces for formulation and optimum design problem and controlling the design process. Current Design Framework tested by two analysis solver, ADAMS and ANSYS. First this paper focused on the core Framework and their conception. In the second of the paper, I cover subjects such as Design Framework Operation. Next, The validity and effectiveness of Design Framework are shown by applying it to many practical design problems and obtaining satisfactory results. Finally, if you are an advanced Operator, you might want to use Response Surface Method, so that cover the result applied by RSM. here.

• Archives of Plastic Surgery
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• 제37권2호
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• pp.178-181
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• 2010

Purpose: Retronychia is the embedding of the nail into proximal nail fold. Retronychia starts with disruption of the longitudinal growth of the nail. With the growth of a new nail, the old one is pushed upwards and backwards. This leads to embedding of the top nail into the ventral aspect of the proximal nail fold and results with chronic paronychia. We present a case of retronychia that was rarely reported in the literature. Methods: A 46-year old female presented with a 3-month history of painful right first, 2nd, 3rd toenail changes. Although she was initially treated with broad spectrum antibiotics, she did not response to therapy. Later, she presented to our department because of progressively worsening pain that impaired her walking. Physical examination revealed with proximal nail fold erythema, painful swelling, yellowish nail discoloration, and distal onycholysis. Bacterial and fungus culture showed no organism. Treatment was surgical nail avulsion under local anesthesia. Results: The postoperative course was uneventful. 10 months later, the patient had a normal growing nail and was free of symptoms. Conclusion: We report a case of retronychia on toenail. Retronychia is a proximal nail plate ingrowth into the proximal nail fold which is associated with multiple generations of nail plate misaligned beneath the proximal nail. Management consisted of simple avulsion of superimposed nail. Retronychia is suspected with a persistent paronychia, particularly in the setting of trauma. Avulsion of the top nail confirms the diagnosis and may be curative if the underlying nail appears healthy.

• Journal of Astronomy and Space Sciences
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• 제28권3호
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• pp.173-181
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• 2011

Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Mt. Bohyun Observatory to measure the Earth's magnetic field variations in South Korea. We, in 2007, installed a fluxgate magnetometer (RFP-523C) to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we provide the preliminary and the first statistical analysis using the BOH magnetometer installed at Mt. Bohyun Observatory. By superposed analysis, we find that daily variations of H, D, and Z shows similar tendency, that is, about 30 minutes before the meridian (11:28) a minimum appears and the time after about 3 hours and 30 minutes (15:28) a maximum appears. Also, a quiet interval start time (19:06) is near the sunset time, and a quiet interval end time (06:40) is near the sunrise time. From the sunset to the sunrise, the value of H has a nearly constant interval, that is, the sun affects the changes in H values. Seasonal variations show similar dependences to the sun. Local time variations show that noon region has the biggest variations and midnight region has the smallest variations. We compare the correlations between geomagnetic variations and activity indices as we expect the geomagnetic variation would contain the effects of geomagnetic activity variations. As a result, the correlation coefficient between H and Dst is the highest (r = 0.947), and other AL, AE, AU index and showed a high correlation. Therefore, the effects of geomagnetic storms and geomagnetic substorms might contribute to the geomagnetic changes significantly.

• Structural Engineering and Mechanics
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• 제25권1호
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• pp.53-73
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• 2007

In this study, an effective load increment method for multi modal adaptive non-linear static (pushover) analysis (NSA) for building type structures is presented. In the method, lumped plastisicity approach is adopted and geometrical non-linearties (second-order effects) are included. Non-linear yield conditions of column elements and geometrical non-linearity effects between successive plastic sections are linearized. Thus, load increment needed for formation of plastic sections can be determined directly (without applying iteration or step-by-step techniques) by using linearized yield conditions. After formation of each plastic section, the higher mode effects are considered by utilizing the essentials of traditional response spectrum analysis at linearized regions between plastic sections. Changing dynamic properties due to plastification in the system are used on the calculation of modal lateral loads. Thus, the effects of stiffness changes and local mechanism at the system on lateral load distribution are included. By using the proposed method, solution can be obtained effectively for multi-mode whereby the properties change due to plastifications in the system. In the study, a new procedure for determination of modal lateral loads is also proposed. In order to evaluate the proposed method, a 20 story RC frame building is analyzed and compared with Non-linear Dynamic Analysis (NDA) results and FEMA 356 Non-linear Static Analysis (NSA) procedures using fixed loads distributions (first mode, SRSS and uniform distribution) in terms of different parameters. Second-order effects on response quantities and periods are also investigated. When the NDA results are taken as reference, it is seen that proposed method yield generally better results than all FEMA 356 procedures for all investigated response quantities.