• 제목/요약/키워드: Standard light source

검색결과 139건 처리시간 0.024초

Atmospheric Turbulence Simulator for Adaptive Optics Evaluation on an Optical Test Bench

  • Lee, Jun Ho;Shin, Sunmy;Park, Gyu Nam;Rhee, Hyug-Gyo;Yang, Ho-Soon
    • Current Optics and Photonics
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    • 제1권2호
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    • pp.107-112
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    • 2017
  • An adaptive optics system can be simulated or analyzed to predict its closed-loop performance. However, this type of prediction based on various assumptions can occasionally produce outcomes which are far from actual experience. Thus, every adaptive optics system is desired to be tested in a closed loop on an optical test bench before its application to a telescope. In the close-loop test bench, we need an atmospheric simulator that simulates atmospheric disturbances, mostly in phase, in terms of spatial and temporal behavior. We report the development of an atmospheric turbulence simulator consisting of two point sources, a commercially available deformable mirror with a $12{\times}12$ actuator array, and two random phase plates. The simulator generates an atmospherically distorted single or binary star with varying stellar magnitudes and angular separations. We conduct a simulation of a binary star by optically combining two point sources mounted on independent precision stages. The light intensity of each source (an LED with a pin hole) is adjustable to the corresponding stellar magnitude, while its angular separation is precisely adjusted by moving the corresponding stage. First, the atmospheric phase disturbance at a single instance, i.e., a phase screen, is generated via a computer simulation based on the thin-layer Kolmogorov atmospheric model and its temporal evolution is predicted based on the frozen flow hypothesis. The deformable mirror is then continuously best-fitted to the time-sequenced phase screens based on the least square method. Similarly, we also implement another simulation by rotating two random phase plates which were manufactured to have atmospheric-disturbance-like residual aberrations. This later method is limited in its ability to simulate atmospheric disturbances, but it is easy and inexpensive to implement. With these two methods, individually or in unison, we can simulate typical atmospheric disturbances observed at the Bohyun Observatory in South Korea, which corresponds to an area from 7 to 15 cm with regard to the Fried parameter at a telescope pupil plane of 500 nm.

근적외선 분광법을 이용한 돈분뇨 액비 성분분석기 개발을 위한 기초 연구 (Basic Study on the Development of Analytical Instrument for Liquid Pig Manure Component Using Near Infra-Red Spectroscopy)

  • 최동윤;곽정훈;박치호;정광화;김재환;송준익;유용희;정만순;양창범
    • 한국축산시설환경학회지
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    • 제13권2호
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    • pp.113-120
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    • 2007
  • 본 시험은 근적외선분광법을 이용한 돈분뇨 액비의 질소, 인산, 칼리, 수분 및 유기물의 분석 가능성을 구명하고, 이를 활용한 분석기의 개발을 목적으로 수행하였으며, 그 결과는 다음과 같다. 1. 돈분뇨 액비시료는 $400{\sim}2,500nm$ 대역의 근적외선을 시료에 투과하여 측정하였으며, 동일시료에 대한 습식분석 결과, N, $P_2O_5,\;K_2O$, 수분 및 유기물 함량은 각각 1,555mg/l, 302mg/l, 240mg/l, 98.8%, 0.53%로 조사되었다. 2. 근적외선 분광광도법을 이용한 분석에서 N, $P_2O_5,\;K_2O$, 수분 및 유기물에 대한 RSQ ($r^2$, R, Coefficient of determination)는 각각 0.9190, 0.9749, 0.5046, 0.9883 및 0.9777이었고 SEC(Standard Error of Calibration)는 2.1649, 0.5019, 1.9252, 0.1180 및 0.0789였다. 3. 액비에 대한 이화학적 습식분석과 NIR 흡수스펙트럼 측정결과를 비교 분석하여 돈 분뇨 액비에 포함된 질소, 인산, 칼리, 수분 및 유기물 함량을 실시간으로 분석하고 액비 성분량을 자동 계산할 수 있는 알고리즘을 도입한 액비분석 프로그램을 작성하였다. 4. 액비 성분분석 시작기는 근적외선(NIR : Near InfraRed)을 받아들여 실시간으로 액비성분의 흡수율을 측정하는 광검출장치(NIR Spectrometer), 근적외선 Light Source로부터 나오는 빛을 반사시키는 반사경, 액비성분 분석용 시료를 넣어 측정하는 Cell Mount, $400{\sim}2,500nm$ 대역의 가시광선-근적외선을 방출하는 Tungsten halogen lamp, NIR Spectrometer와 Tungsten halogen lamp로 전압을 입력시켜 주는 Power Supply Module 및 전체를 Black Anodizing한 외형으로 구성되었다. 5. 실험결과, 칼리를 제외한 액비내 모든 성분이 광을 흡수하는 강도는 성분의 농도에 비례하였으며 원시 스펙트럼의 중첩 제거 및 빛의 산란보정을 통해 액비의 질소, 인산성분, 수분 및 유기물 함량을 측정하는데 효과적으로 이용할 수 있을 것으로 사료되며, 분광분석법을 이용한 액비성분 분석기 개발이 완료되면 현장에서 신속하고 정확한 분석이 가능할 것으로 판단된다.

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경량칸막이 벽체를 통한 다중구획공간에서의 화재위험성에 관한 연구 (A Study on Fire Hazards in Multiple Compartments with Lightweight Partition Walls)

  • 박상민;최수길;진세영;김시국
    • 한국화재소방학회논문지
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    • 제34권2호
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    • pp.14-21
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    • 2020
  • 본 논문은 ISO 9705 2/5축소모델 2개를 실내 공간구획에 사용되는 경량칸막이를 이용하여 구획 한 후 ISO 9705 시험을 재현하여 이면부로의 화재위험성에 관한 연구이다. 실험 시료는 시공 시 가장 많이 사용되고 있는 SGP 칸막이, 스터드 칸막이, 그라스울 패널, 우레탄폼 패널, 샌드위치 패널, 유리 칸막이를 선정 하였고, ISO 9705시험 기준에 따라 버너에 점화 전 측정 장치와 데이터의 기록을 시작하여 120 s간 유지시켜 안정화를 취하고, 점화 후 600 s 동안 100 kW, 이후 600 s 동안 300 kW까지 증가하였다가 종료 후 180 s동안 관찰하여 이면부로의 화재 위험성 및 벽체의 화재 패턴을 분석하였다. 점화원에서 발생된 열량으로 인한 최대 이면온도는 SGP 칸막이 67.7 ℃, 스터드 칸막이 55.1 ℃, 그라스울 패널 52.4 ℃, 샌드위치 패널 727.4 ℃, 우레탄폼 패널 561 ℃, 유리 칸막이 630.5 ℃로 측정되었다. 샌드위치 패널과 우레탄폼 패널의 경우 내장재에 용융으로 인한 가연성 가스의 폭발 현상이 발생하였고 강화유리는 수열부와 비수열부의 온도차이로 인하여 유리가 파열되며 인접구획실로의 화재 위험성이 높은 것으로 판단된다.

하수오(何首烏)의 품질인증(品質認證) 방안(方案) (Quilitative certificational plan of heshouwu)

  • 신미경;노성수;길기정;서부일;서영배
    • 혜화의학회지
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    • 제13권2호
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    • pp.205-212
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    • 2004
  • Now many sustitution and false articles is used in korea instead of heshouwu. To use heshouwu correctly, we will make a quilitative certificational plan of heshouwu to investigate all of lieraturea, records and documents. And we could reach conclusions as folloews. 1) Source of plant Heshouwu is a root tuber of a perennial herb Polygonum multiflorum Thunberg(Family : Polygonaceae). 2) Harvest After planting 3-5 yaers, harvesting in an autumn, washin clean the mud, a big heshouwu cut off a half or section, dry in sunny place or at a little fire. When harvesting, we harvest only a big thing, a small thing transfer a field, after culturing of 1-2 years, harvest at big roots. Harvesting is done usually in an autumn after 3 years. When collecting a seed, we must harvest a heshouwu the next year. 3) Process We must process heshouwu at the decoction of black beans, heshouwu suck in the decoction of black beans, heat with steam in an iron pot. Black beans is used every 100 kg of heshouwu. 4) Quility (1) Funstional standards It is good that weight is heavy and outer skin is yellow-brown, section surface is light red color, powdery and has a figure such as clouds in section. (2) Physicochemical standards Heshouwu expesses a various chang of components in process of working. We think that it need to add a standard of detection about 2,3,5,4'-tetrahrdroxystilbene-2-O-${\beta}$ -D-glucoside in a current authentic document which is a water-soluble component of heshouwu. It must that Dry on loss is less than 14.0%, content of ash is less than 5.0%, Content of acid-nonsoluble ash is less than 1.5%, Content of extract is more than 17.0%. A fixed quantity of 2,3,5,4'-tetrahrdroxystilbene-2-O-${\beta}$ -D-glucoside is more than 1.0%. Contens of heavy metal has to detect less than 30 ppm and there is no reminding agriculural medince.

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기상관측용 투과형 시정계의 국제단위계에 소급하는 교정 (SI-traceable Calibration of a Transmissometer for Meteorological Optical Range (MOR) Observation)

  • 박성종;이동훈;김용규
    • 한국광학회지
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    • 제26권2호
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    • pp.73-82
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    • 2015
  • 본 논문은 일정 두께를 정하여 대기의 시감투과율을 측정함으로써 시정거리의 표준화된 양인 기상학적 광학거리(Meteorological Optical Range, MOR)를 관측하는, 기상관측용 투과계의 국제단위계에 소급하는 실내 교정방법과 그 교정 예를 소개하고 있다. 국제단위계 유도량 중 하나인 시감투과율 눈금을 교정대상 투과계에 전달해주기 위한 기준물로서 시감투과율 0.2 % ~ 99.5 % 범위의 OD 0.1 ~ 2.5 의 ND 필터와 석영유리, 무반사처리된 석영유리 등 총 20종을 이용하였고, 이 기준물의 분광투과율은 한국표준과학연구원의 분광투과율 표준기를 이용하여 교정된 것이다. 교정 대상 투과계는 기준거리 - 수광부와 검출부 사이의 거리 - 가 75 m 이고 측정광으로는 색온도 약 5000 K의 백색 LED를 이용하고, 광검출기로는 CIE 1924 V(${\lambda}$) 분광응답을 갖는 광도계를 이용하는 방식이다. 교정은 기준물을 투과계 사이에 위치하여 투과계가 표출하는 시감투과율 및 MOR 값을 기준값과 비교하는 방식으로 이루어졌으며, 교정 결과 20 m ~ 40 km 범위의 MOR에 대하여 MOR 오차와 그 불확도를 산출 할 수 있었다. 교정결과를 토대로 본 연구에서 소개하는 교정방법과 교정결과가 국제민간항공기구(International Civil Aviation Organization, ICAO)의 시정관측의 정확도 요건에 부합할 수 있는지를 고찰하였다.

다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형 (The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM)

  • 박지영;홍태호
    • Asia pacific journal of information systems
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    • 제19권2호
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.

TiO2 광촉매 산화 반응에서 생성된 수산기 라디칼 분석 방법 (Analytical Methods of Hydroxyl Radical Produced by TiO2 Photo-catalytic Oxidation)

  • 김성희;이상우;김정진;김순오
    • 한국광물학회지
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    • 제28권3호
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    • pp.245-253
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    • 2015
  • $TiO_2$ 광촉매 산화 공정의 효율은 수산기 라디칼의 생성량에 따라 크게 의존한다. 따라서 생성되는 수산기 라디칼의 정확한 정량이 공정을 평가하는데 필수적이다. 하지만 아직까지 이러한 수산기 라디칼 정량법이 마련되지 못했다. 이에 본 연구는 $TiO_2$ 광촉매 산화 반응에서 생성되는 수산기 라디칼을 정량화하기 위한 기존 분석법들을 비교하고, 기존 분석법들의 단점을 극복할 수 있는 새로운 방법을 제안하고자 수행되었다. $TiO_2$ 광촉매 산화 반응을 모사하기 위하여, 표준 $TiO_2$ 광촉매로서 널리 이용되고 있는 Degussa P25를 사용하였으며, 투여량은 0.05 g/L이었다. 그리고 UVC 수은 저압램프(11 W, $2,975mW/cm^2$)를 광원으로 이용하였다. 연구결과, 기존에 많이 활용되고 있는 요오드화칼륨(KI)/UV-vis 분광분석법과 테레프탈산(TPA)/형광 분광분석법은 각각 요오드이온(I-)과 테레프탈산을 공정 중 생성된 수산기 라디칼과 반응시켜 발생하는 삼중요오드이온($I_3{^-}$)과 2-하이드록시 테레프탈산을 검출하여 수산기 라디칼의 생성여부만을 확인할 수 있는 정성적인 분석법들이었다. 하지만 본 연구에서 테레프탈산 방법을 고성능 액체 크로마토그래프(HPLC) 분석법과 연계하였을 때 수산기 라디칼의 정량화가 가능하였다. 이렇게 새롭게 개발된 TPA/HPLC 분석법을 이용하여 측정한 결과, 본 연구의 실험 조건에서 8시간의 광촉매 산화 공정에 의해서 0.013 M의 수산기 라디칼이 생성되는 것을 확인하였다. 본 연구에서 제안하는 수산기 라디칼 정량법은 광촉매 산화 공정의 성능을 평가하는데 기여할 것으로 기대된다.

Small-Angle X-ray Scattering Station 4C2 BL of Pohang Accelerator Laboratory for Advance in Korean Polymer Science

  • Yoon, Jin-Hwan;Kim, Kwang-Woo;Kim, Je-Han;Heo, Kyu-Young;Jin, Kyeong-Sik;Jin, Sang-Woo;Shin, Tae-Joo;Lee, Byeong-Du;Rho, Ye-Cheol;Ahn, Byung-Cheol;Ree, Moon-Hor
    • Macromolecular Research
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    • 제16권7호
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    • pp.575-585
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    • 2008
  • There are two beamlines (BLs), 4C1 and 4C2, at the Pohang Accelerator Laboratory that are dedicated to small angle X-ray scattering (SAXS). The 4C1 BL was constructed in early 2000 and is open to public users, including both domestic and foreign researchers. In 2003, construction of the second SAXS BL, 4C2, was complete and commissioning and user support were started. The 4C2 BL uses the same bending magnet as its light source as the 4C1 BL. The 4C1 BL uses a synthetic double multilayer monochromator, whereas the 4C2 BL uses a Si(111) double crystal monochromator for both small angle and wide angle X-ray scattering. In the 4C2 BL, the collimating mirror is positioned behind the monochromator in order to enhance the beam flux and energy resolution. A toroidal focusing mirror is positioned in front of the monochromator to increase the beam flux and eliminate higher harmonics. The 4C2 BL also contains a digital cooled charge coupled detector, which has a wide dynamic range and good sensitivity to weak scattering, thereby making it suitable for a range of SAXS and wide angle X-ray scattering experiments. The general performance of the 4C2 BL was initially tested using standard samples and further confirmed by the experience of users during three years of operation. In addition, several grazing incidence X-ray scattering measurements were carried out at the 4C2 BL.

디자인의 형태와 기능에 관한 연구 (Essay on Form and Function Design)

  • 이재국
    • 디자인학연구
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    • 제2권1호
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    • pp.63-97
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    • 1989
  • There is nothing more important than the form and function in design, because every design product can be done on the basis of them. Form and Function are already existed before the word of design has been appeared and all the natural and man-made things' basic organization is based on their organic relations. The organic relations is the source of vitality which identifies the subsistance of all the objects and the evolution of living creatures has been changed their appearances by the natural law and order. Design is no exception. Design is a man-made organic thing which is developed its own way according to the purposed aim and given situations. If so, what is the ultimate goal of design. It is without saying that the goal is to make every effort to contribute to the -human beings most desirable life by the designer who is devoting himself to their convenience and well-being. Therefore, the designer can be called the man of rich life practitioner. This word implies a lot of meanings since the essence of design is improving the guality of life by the man-made things which are created by the designer. Also, the things are existed through the relations between form and function, and the things can keep their value when they are answered to the right purpose. In design, thus, it is to be a main concern how to create valuable things and to use them in the right way, and the subject of study is focused on the designer's outlook of value and uk relations between form and function. Christopher Alexander mentioned the importance of form as follows. The ultimate object of design is form. Every design problem begins with an effort to achieve fittness between the form and its context. The form is the solution to the problem: the context defmes the problem. In other words, when we speak of design, the real object of discussion is not form alone, but the ensemble comprising the form and its context. Good fit is a desirable property of this ensemble which relates to some particular division of the ensemble into form and context. Max Bill mainatined how important form is in design. Form represents a self-contained concept, and its embodiment in an object results in that object becoming a work of art. Futhermore, this explains why we use form so freguently in a comparative sense for determining whether one thing is less or more beautiful than another, and why the ideal of absolute beauty is always the standard by which we appraise form, and through form, art itself. Hence form has became synonymous with beauty. On the other hand, Laszlo Moholy-Nagy stated the importance of function as follows. Function means the task an object is designed to fulfill the task instrument is shaping the form. Unfortunately, this principle was not appreciated at the same time but through the endeavors of Frank Lloyd Wright and of the Bauhaus group and its many collegues in Europe, the idea of functionalism became the keynote of the twenites. Functionalism soon became a cheap slogan, however, and its original meaning blurred. It is neccessary to reexamine it in the light of present circumstances. Charles William Eliot expressed his idea on the relations between function and beauty. Beauty often results chiefly from fittness: indeed it is easy to manitain that nothing is fair except what is fit its uses or functions. If the function of the product of a machine be useful and valuable, an the machine be eminently fit for its function, it conspicuously has the beauty of fittness. A locomotive or a steamship has the same sort of beauty, derived from the supreme fittness for its function. As functions vary, so will those beauty..vary. However, it is impossible to study form and function in separate beings. Function can't be existed without form, and without function, form is nothing. In other words, form is a function's container, and function is content in form. It can be said that, therefore, the form and function are indispensable and commensal individuals which have coetemal relations. From the different point of view, sometimes, one is more emphasized than the other, but in this case, the logic is only accepted on the assumption of recognizing the importance of the other's entity. The fact can be proved what Frank Hoyd wright said that form and function are one. In spite of that, the form and function should be considered as independent indivisuals, because they are too important to be treated just as the simple single one. Form and function have flexible properties to the context. In other words, the context plays a role as the barometer to define the form and function, also which implies every meaning of surroun'||'&'||'not;dings. Thus, design is formed under the influence of situations. Situations are dynamic, like the design process itself, in which fixed focus can be cripping. Moreover, situations control over making the good design. Judging from the respect, I defined the good design in my thesis An Analytic Research on Desigh Ethic, "good design is to solve the problem by the most proper way in the situations." Situations are changeable, and so is design. There is no progress without change, but change is not neccessarily progress. It is highly desirable that there changes be beneficial to mankind. Our main problem is to be able to discriminate between that which should be discarded and that which should be kept, built upon, and improved. Form and Function are no exception. The practical function gives birth to the inevitable form and the $$\mu$ti-classified function is delivered to the varieties of form. All of these are depended upon changeable situations. That is precisely the situations of "situation de'||'&'||'not;sign", the concept of moving from the design of things to the design of the circumstances in which things are used. From this point of view, the core of form and function is depended upon how the designer can manage it efficiently in given situations. That is to say that the creativity designer plays an important role to fulfill the purpose. Generally speaking, creativity is the organization of a concept in response to a human need-a solution that is both satisfying and innovative. In order to meet human needs, creative design activities require a special intuitive insight which is set into motion by purposeful imagination. Therefore, creativity is the most essential quality of every designer. In addition, designers share with other creative people a compulsive ingenuity and a passion for imaginative solutions which will meet their criteria for excellence. Ultimately, it is said that the form and function is the matter which belongs to the desire of creative designers who constantly try to bring new thing into being to create new things. In accordance with that the main puppose of this thesis is to catch every meaning of the form and function and to close analyze their relations for the promotion of understanding and devising practical application to gradual progression in design. The thesis is composed of four parts: Introduction, Form, Function and Conclusion. Introduction, the purpose and background of the research are presented. In Chapter I, orgin of form, perception of form, and classification of form are studied. In Chapter II, generation of function, development of function, and diversification of function are considered. Conclusion, some concluding words are mentioned.ioned.

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