• 제목/요약/키워드: Analytical Techniques

검색결과 939건 처리시간 0.024초

태양에너지 박막의 광퇴화 연구를 위한 표면분석 (Surface Analysis Techniques for Studying Optical Degradation of Solar Coatings)

  • 이길동
    • 한국태양에너지학회 논문집
    • /
    • 제29권2호
    • /
    • pp.55-61
    • /
    • 2009
  • This paper reviews the state-of-the art in surface analysis techniques for solar coatings. For analyzing solar coatings and interfaces, surface properties were very important factor for obtaining the information related to the optical degradation processes and microstructure. Various types of analytical techniques for chemical composition, microstructure and surface topography analysis of solar coatings were discussed. In addition, the examples of solar selective coating analysis results for applications were demonstrated. Development and analysis technique of solar coating for energy conservation was felt to be necessary at this time.

Preliminary Research on the Uncertainty Estimation in the Probabilistic Designs

  • Youn Byung D.;Lee Jae-Hwan
    • Journal of Ship and Ocean Technology
    • /
    • 제9권1호
    • /
    • pp.64-71
    • /
    • 2005
  • In probabilistic design, the challenge is to estimate the uncertainty propagation, since outputs of subsystems at lower levels could constitute inputs of other systems or at higher levels of the multilevel systems. Three uncertainty propagation estimation techniques are compared in this paper in terms of numerical efficiency and accuracy: root sum square (linearization), distribution-based moment approximation, and Taguchi-based integration. When applied to reliability-based design optimization (RBDO) under uncertainty, it is investigated which type of applications each method is best suitable for. Two nonlinear analytical examples and one vehicle crashworthiness for side-impact simulation example are employed to investigate the unique features of the presented techniques for uncertainty propagation. This study aims at helping potential users to identify appropriate techniques for their applications in the multilevel design.

러브파의 위상속도 분산정보에 관한 해석적 연구 (Analytical Study for dispersed Phase Velocity Information of Love Waves)

  • 이일화
    • 한국철도학회논문집
    • /
    • 제7권4호
    • /
    • pp.391-399
    • /
    • 2004
  • This paper investigated the dispersion characteristics of horizontal surface waves as means to apply conversional SASW techniques. To verify this proposal, 3D finite element analysis and Transfer matrix solution were performed. SH wave(Love waves) has the some advantages in comparison with Rayleigh wave. Representatively, Love wave has a characteristics not affected by compression wave. These characteristics have the robust applicability for the surface wave investigation techniques. In this study, for the purpose of employing Love wave in the SASW method, the dispersion characteristics of the Love wave was extensively investigated by the theoretical and numerical approaches. The 3-D finite element and transfer matrix analyses for the half space and two-layer systems were performed to determine the phase velocities from Love wave as well as from both the vertical and the horizontal components of Rayleigh wave. Preliminary, numerical simulations and theoretical solutions indicated that the dispersion characteristics of horizontal surface wave(Love waves) can be sufficiently sensitive and appliable to SASW techniques.

Efficiently Solving Dispatching Process Problems in Nurseries by Heuristic Techniques

  • Erhan, Kozan
    • Industrial Engineering and Management Systems
    • /
    • 제1권1호
    • /
    • pp.10-18
    • /
    • 2002
  • A more comprehensive analytical framework for examining the relative merits of alternative dispatching process policies for nurseries is developed in this paper. The efficiency of the dispatch process of plants in a nursery is analysed using a vehicle routing model. The problem then involves determining in what order each vehicle should visit its locations. The problem is NP-hard. Several heuristic techniques are used to solve a real life nursery sequencing problem. The results obtained by these heuristic techniques are compared with each other and the current sequencing of orders. The model with some minor alterations can be also used to minimise the dispatching and collecting process in different agricultural plants.

System Level ESD Analysis - A Comprehensive Review I on ESD Generator Modeling

  • Yousaf, Jawad;Lee, Hosang;Nah, Wansoo
    • Journal of Electrical Engineering and Technology
    • /
    • 제13권5호
    • /
    • pp.2017-2032
    • /
    • 2018
  • This study presents, for the first time, state-of-the art review of the various techniques for the modeling of the electrostatic discharge (ESD) generators for the ESD analysis and testing. After a brief overview of the ESD generator, the study provides an in-depth review of ESD generator modeling (analytical, circuit and numerical modeling) techniques for the contact discharge mode. The proposed techniques for each modeling approach are compared to illustrates their differences and limitations.

Construction Cost Forensics: How Best To Protect Your Company And Avoid Costly Problems

  • Opfer, Neil
    • 국제학술발표논문집
    • /
    • The 9th International Conference on Construction Engineering and Project Management
    • /
    • pp.1240-1240
    • /
    • 2022
  • Construction projects are fraught with risks from cost or other overruns to accidents along with other issues. This is true whether the relevant organization is an owner, general contractor, CM, specialty-trade contractor, or other entity. When cost issues or other issues confront arise, how should an organization proceed whether attempting to gain additional compensation in terms of cost/other damages or protecting the same against such claims if they do not appear to be warranted? Enter construction cost forensics. This presentation will focus on strategies/techniques with construction cost forensics in these areas in order to be successful. Covered techniques include those to develop and analyze claims including fundamental construction cost analysis techniques. When an unexpected event disrupts a construction project, using sound analytical methods to identify the cause and quantify the extent of the issue will be important for negotiating a fair result or for obtaining a successful outcome in arbitration or litigation. Key examples of uncovering issues via construction cost forensics will be covered in this presentation.

  • PDF

영화 사례분석을 통한 디지털 분장 기법에 관한 연구 (A Study of Digital Makeup Techniques, based on a Case Study of a Film)

  • 문정은;김숙진
    • 복식
    • /
    • 제61권5호
    • /
    • pp.48-63
    • /
    • 2011
  • Digital makeup(DM), depending upon computer graphic softwares, is applied to various fields, e.g. character works in movie and game industries and visual printouts in printing works. Focused on makeup field, DM is extremely conducive to developing, scientizing and informationalizing makeup patterns. Despite of unlimited potential of DM of which market size has been growing day by day, its practical use by domestic makeup experts and educators is much less active than expected as far, due to the lack of knowledge accumulation. The purpose of this study is to suggest some theoretical frameworks to generalize DM techniques and analyze two cases using the frames therefore support academicians' recent efforts to theorize DM techniques. The study 1) defines and categorizes the concepts of DM and DFX(digital special effect); 2) reviews the literature relevant to DM and generalizes the types and methods of DM techniques; 3) applies general frames to analyzing two movie cases, famous for their DM effects; 4) then suggests, based upon analytical results, some efficient ways for makeup experts to use DM techniques in practice. This study contributes to providing the theoretical grounds to conceptualize DM thus broadening makeup artists' interests in DM and awakening the scholarly concerns in cultural technology including DM.

Aflacxin에 대한 최신 분석법과 규제동향 (Development of Rapid, Safe Analytical Techniques of Aflatoxins and Their Current Regulation)

  • 정덕화
    • 한국식품위생안전성학회지
    • /
    • 제5권3호
    • /
    • pp.131-138
    • /
    • 1990
  • Aflatoxins is a chemically diverse group of toxic secondary metabolites that are produced by fungi and often occur in agricultural commodities. Because of their wide range of toxic effects, Aflatoxins cause severe economic losses to farmers and livestock producers and pose a health to human consuming contaminated foods. Long term prospects for biotechnological control of Aflatoxins require elucidation of the specific steps and regulation of their biosynthetic pathways . Aflatoxin determinations can be approached many ways. It is essential to safely handle all experimental materials associated with aflatoxin analysis or aflatoxigenic fungi Visual screening of suspect samples, base on the presence of conidial head of the aspergillus flavus group, and screening samples for the presence of bright greenish yellow flourescence are not chemical tests and such screening techniques may allow aflactoxin contaminated lots into commerce. Microcolumn screening procedures should always be used in conjunction with a quantitative method. Several thin layer chromatography(TLC) and high performance liquid chromatography(HPLC) methods are suitable for quantitation and are in general use. Immunochemical Methods such as the ELISA or affinity column chromatography methods are being rapidly developed. The chemical and immunochemical methods can be reliable if care is taken, using suitable controls and personnel that are well trained . All analytical laboratories should stress safety and include suitable analytical validation procedure. Especially a worldwide enquiry was undertaken in recent to obtain up-to-date information about aflatoxin legislation in as many countries of the world as possible. The information concerns aflatoxin in foodstuffs. aflatoxin MI in dairy products, aflatoxins in animal feedstuffs. Limits and regulations for aflatoxin have been expended in recent with more countries having legislation on subject, more products, and more aflatoxins covered by this legislation.

  • PDF

Optimization of Analytical Procedure for Hydrogen Cyanide in Mainstream Smoke

  • Lee, John-Tae;Kim, Hyo-Keun;Hwang, Keon-Joong;Jang, Gi-Chul;Lee, Jeong-Min;Kim, Ick-Joong
    • 한국연초학회지
    • /
    • 제29권2호
    • /
    • pp.125-131
    • /
    • 2007
  • Hydrogen cyanide(HCN), formed from pyrolysis of various nitrogenous compounds such as protein, amino acids and nitrate in tobacco, is present in both the particulate phase and vapor phase of cigarette smoke. Typically the determination of HCN in cigarette smoke has been done through colorimetric and electrochemical techniques, such as fluorescence spectrometry, UV-spectrophotometry (UV), continuous flow analyzer (CFA), capillary GC-ECD and ion chromatography (IC). Most of these techniques are known to be time-consuming and some of them lack specificity or sensitivity. The available results from both our laboratory and reported literatures for 2R4F Kentucky reference cigarette, smoked under ISO condition, show a relatively wide variation ranging from 100 to 120 ug/cig of HCN. Especially, the precision and accuracy of the analytical results of HCN tend to get worse in low tar cigarettes and under intense smoking condition. In this paper, a more optimized analytical methods than previous ones are suggested. This method shows lower detection limit and has improved precision and accuracy, so it is applicable for wide tar level cigarettes under intense smoking condition as well as under ISO smoking condition. Important features of this method are improved sample collection and quantification systems such as the number of trapping units, volume, temperature and type of trapping solution. To avoid volatilization loss of HCN in analyzing mainstream smoke, it is highly recommended that pH values of trapping solutions should be maintained over 11 and cold traps should be used in collecting mainstream smoke.

Fusarium 곰팡이독소 T-2 독소와 HT-2 독소의 국.내외 연구동향 (Trends in Researches of Fusarium Mycotoxins, T-2 toxin and HT-2 toxin in Domestic and Foreign Countries)

  • 이수진;김미혜;오상석;전향숙
    • 한국식품위생안전성학회지
    • /
    • 제27권1호
    • /
    • pp.1-17
    • /
    • 2012
  • T-2 toxin and HT-2 toxin, belong to type A trichothecences, are the most toxic mycotoxins among the trichothecene family. These mycotoxins are commonly found in cereals such as maize, wheat, barley, oats and rice, and their occurrence in food can be of concern. This review investigated the current trends of patents and researches on T-2 toxin and HT-2 toxin pertaining to natural occurrence, toxicity, metabolism, risk assessment, analytical and screening methods, and reduction/detoxification techniques. As compared with other $Fusarium$ mycotoxins, there are limited data for natural occurrence and risk assessment, and regulatory limit and official analytical methods on T-2 toxin and HT-2 toxin in domestic and foreign countries. In particular, selective deacetylation at the C3 and/or C4 positions of T-2 toxin by carboxyesterase present in foods was reported to cause the disappearance of T-2 and the extremely high HT-2 recoveries. Currently, regulatory limits for T-2 and HT-2 are under discussion in EU. For enforcement purposes it is essential to have available precise and reliable analytical methods applicable at the regulatory levels for the T-2 toxin and HT-2 toxin and relevant commodities. In addition, a further study on natural occurrence, risk assessment and reduction/detoxification techniques will be recommended.