• Title/Summary/Keyword: Reference standard

Search Result 2,185, Processing Time 0.029 seconds

Role and Prospective of Reference Standards for Integrity Controls of Large-scale Structure and Facilities (대형 설비/구조물 안전성에 있어서 국가참조표준의 역할과 전망)

  • Nahm, Seung-Hoon;Lee, Yun-Hee;Baek, Un-Bong;Chung, In-Hyun;Lee, Hae-Moo
    • Proceedings of the KSME Conference
    • /
    • 2007.05a
    • /
    • pp.84-89
    • /
    • 2007
  • In order to guarantee the safety of the facility systems, one of the essential components is information on mechanical properties of materials used for the construction. However, acquisition or accumulation of the mechanical property data in industrial fields is limited because this operation does not yield profit, excepting few materials production companies. Corresponding to the urgent needs and poor economical features, the MOCIE has founded the National Center for Standard Reference Data in the KRISS and also designated the Data Center of Mechanical Properties for Metallic Materials (DCMP) as a principal operating section. The DCMP plays roles of collection, edition and evaluation of the mechanical data and development of reference standards. In this study, several functions of the DCMP and standardization procedures of mechanical properties data will be introduced the prospective of standard reference researches will be discussed based on active feedbacks from industrial fields.

  • PDF

Averaging Current Adjustment Technique for Reducing Pixel Resistance Variation in a Bolometer-Type Uncooled Infrared Image Sensor

  • Kim, Sang-Hwan;Choi, Byoung-Soo;Lee, Jimin;Lee, Junwoo;Park, Jae-Hyoun;Lee, Kyoung-Il;Shin, Jang-Kyoo
    • Journal of Sensor Science and Technology
    • /
    • v.27 no.6
    • /
    • pp.357-361
    • /
    • 2018
  • This paper presents an averaging current adjustment technique for reducing the pixel resistance variation in a bolometer-type uncooled infrared image sensor. Each unit pixel was composed of an active pixel, a reference pixel for the averaging current adjustment technique, and a calibration circuit. The reference pixel was integrated with a polysilicon resistor using a standard complementary metal-oxide-semiconductor (CMOS) process, and the active pixel was applied from outside of the chip. The averaging current adjustment technique was designed by using the reference pixel. The entire circuit was implemented on a chip that was composed of a reference pixel array for the averaging current adjustment technique, a calibration circuit, and readout circuits. The proposed reference pixel array for the averaging current adjustment technique, calibration circuit, and readout circuit were designed and fabricated by a $0.35-{\mu}m$ standard CMOS process.

Development of Certified Reference Materials for Specific Surface Area (비표면적 인증표준물질 개발)

  • Choi, Byung Il;Kim, Jong Chul;Kim, Taeyoung;Nham, Hyunsoo;Kwon, Su Yong
    • Analytical Science and Technology
    • /
    • v.18 no.1
    • /
    • pp.74-84
    • /
    • 2005
  • Understandings of adsorption characteristic of interface are very important in several advanced materials processes, related to NT and BT technology. Volumetric gas adsorption method, suitable for absolute measurements, is regarded as the standardized measurement technique for specific surface area. In order to verify the reliability of commercial equipments, certified reference materials (called CRM) of specific surface area are developed and evaluated its uncertainty factors by standard equipment which has traceability to SI units. Specific surface areas of developed materials are $10.72{\pm}0.46m^2g^{-1}$ for silicon nitride powders and $149.50{\pm}3.44m^2g^{-1}$ for alumina. These disseminations of CRMs would result in improved reliability chains in industrial processes, and lead eventually to contribution to productivity improvement, quality management, safety evaluation, and possibly to new material development.

Development of reference materials for mortar: Determination of the components and relation with mixing ratio

  • Lim, Dong Kyu;Choi, Myoung Sung
    • Advances in concrete construction
    • /
    • v.10 no.5
    • /
    • pp.381-391
    • /
    • 2020
  • This study aimed to develop reference materials (RMs) for mortar that can simulate the initial flow characteristics with constant quality over a long period. Through the previous research on the development of RMs for cement paste, the combination of limestone, glycerol, and water was used as the basic matrix for developing RMs for mortar in this study. In addition, glass beads of three particle sizes (0.5, 1.0, and 2.0 mm) and ISO standard sand were selected as tentative candidates to derive fine aggregate substitutes. The mixture of glass beads could simulate the initial flow characteristics of mortar, but under the same mixing ratio, replicates showed an unstable tendency to indicate inconsistent values due to the generation of electrostatic properties between materials and equipment. On the other hand, the mixture using ISO standard Sand not only simulates the constant flow characteristics for a long period of time, but also shows stable results with little error in replicates. Therefore, limestone, glycerol, ISO standard sand, and water were finally determined as components that met the required properties of RMs for mortar. The effect of each component on the flow characteristics of RMs was analyzed. It was found that glycerol increased the cohesion between the particles of standard sand, resulting in a constant increase both in the plastic viscosity and yield stress. Both limestone and standard sand had a dominant effect on the yield stress. The relationships between various mortar mixing ratios and the corresponding mixing ratios of RMs were established. In addition, the results of the verification experiment showed that the rheological properties of the RMs obtained through the relationships correlated with various water/cement ratios and the fine aggregate volume fractions of mortar obtained with same manner. In other words, the RMs for mortar developed in this study can be used as standard samples because they can simulate the initial flow characteristics of mortar of various mixing ratios for a long period without any chemical changes.

Studies on the evaluation of efficacy of functional cosmetics(I) -Studies on the in vitro SPF test method of sunscreen products (기능성화장품의 기능성평가에 관한 연구(I) -자위선차단화장품의 in vitro 시험법 연구)

  • 손경훈;김영옥;이정표;양성준;백옥진;김원희;김종갑;허문영;최상숙
    • Journal of the Society of Cosmetic Scientists of Korea
    • /
    • v.28 no.3
    • /
    • pp.171-184
    • /
    • 2002
  • The present study was undertaken to develop the in vitro sunprotection factor(SPF) measurement method having good correlation with in vivo method. As in vitro method, 8% homomentyl salicylate, P3 reference standard and sunscreens on market were measured using SPF 290 analyzer and were compared the SPF with labed value. In vitro SPF of 8% HMS and P3 reference standard were 4.59 $\pm$ 0.12 and 14.94 $\pm$ 0.83. There are good correlation, correlation factor were 0.9506 and 0.9769 respectively, between the in vitro and in vivo SPF for the sunscreen creams and lotions examined. Correlation factors of makeup base & liquid goundation, lotion labled with “shake before use”, compact powder were 0.8812, 0.8632 and 0.5984. The best sample applied method of compact powder was 1:0.8 mixture with cream base. These results suggest that the in vitro test method could be used as an alternative method for SPF.

Comparison of Characteristics and Dispersion of Fasting Blood Glucose Data by Administrative Districts and Gender Difference Using the 2017 'Korean Blood Glucose Reference Standard' (2017 '한국인 혈당 참조표준'을 이용한 행정구역별 남녀별 공복 혈당 데이터의 특성 및 산포성 비교)

  • Kwon, Young-Il
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.52 no.1
    • /
    • pp.28-35
    • /
    • 2020
  • This study aimed to investigate the differences in the upper and lower limits of the 95% distribution of fasting blood glucose (FBG) by age groups. We also analyzed the changes in the mean values and dispersion of the data using the Korean Blood Glucose Reference Standard raw data published by the National Health Insurance Service (NHIS). Furthermore, the trends among 16 administrative districts were analyzed and any gender differences were determined. We also assessed whether the study results correlated with the relative standard uncertainty, as published by the NHIS. On the dispersion analysis using the differences between the upper and lower limits of the 95% distribution of FBG by age group, there were significant differences across gender and administrative districts (P<0.05). The gender differences in FBG measurements, as published by the NHIS, were significant across different administrative districts and age groups (P<0.001). This confirmed the need to recalculate the blood glucose reference standards for men and women. No significant correlation was observed between the relative standard uncertainty, as published by NHIS, and the dispersion and number of measurements analyzed in this study. However, it showed a high correlation with the measured mean value (R2=0.95). Therefore, further research on the reference standard and uncertainty is needed.

Comparison of the Tactile Sensation of Worsted Fabrics With and Without Reference (기준 직물 제시와 비제시 방법에 따른 소모직물의 촉감 평가 비교)

  • 김동옥;김은애
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.28 no.3_4
    • /
    • pp.452-459
    • /
    • 2004
  • The purpose of this study was to evaluate the effect of reference fabric for the tactile sensation of worsted fabrics. As specimens, 32 worsted fabrics for spring/fall suits were selected. A series of subjective evaluation for roughness, harshness, coarseness, smoothness, warmth, bulkiness and softness were performed with 20 trained panels. The panels were selected by the test of consistency and trained for 3 weeks to enhance the reproducibility and consistency. Subjective evaluation was performed using 9 points Semantic Differential Scales with and without reference fabric. Results showed that the sensations were very similar between the results for the test of with or without reference. However the standard deviations of ratings for the with-reference were much less than that of without-reference which means the use of reference fabric can reduce the subjective error or can reduce the number of panels to test.

A Standard Reference Model for Semantic Interoperability in Cloud Computing (클라우드 컴퓨팅에서의 의미 상호운용성을 위한 표준 참조 모델)

  • Jeong, Dong-Won
    • Journal of the Korea Society of Computer and Information
    • /
    • v.17 no.8
    • /
    • pp.71-80
    • /
    • 2012
  • Much research has been recently accomplished for standardization in cloud computing. However, little research on standardization of data sharing and exchanging has been studied. Most of all, the corresponding standardization organization suggests no specific standardization items and reference model. This paper defines the current standardization problems and proposes a set of specific standardization items and a reference model for supporting the semantic interoperability. To achieve the goal of this paper, the overall standardization trend in cloud computing is first analyzed. Especially, this paper describes the status of standard development for addressing the semantic interoperability of data. This paper also defines the potential standardization items based on the concepts of standards in the data exchanging and management field, which are used for developing standards in various fields. Finally, the reference model is describe to show the relationships between items and overall semantic interoperability process. This paper can be used as a guideline for development of standards and also can facilitate standardization of cloud computing.

Characterizing a Full Spectrum of Physico-Chemical Properties of Ginsenosides Rb1 and Rg1 to Be Proposed as Standard Reference Materials

  • Kim, Il-Woung;Hong, Hee-Do;Choi, Sang-Yoon;Hwang, Da-Hye;Her, Youl;Kim, Si-Kwan
    • Journal of Ginseng Research
    • /
    • v.35 no.4
    • /
    • pp.487-496
    • /
    • 2011
  • Good manufacturing practice (GMP)-based quality control is an integral component of the common technical document, a formal documentation process for applying a marketing authorization holder to those countries where ginseng is classified as a medicine. In addition, authentication of the physico-chemical properties of ginsenoside reference materials, and qualitative and quantitative batch analytical data based on validated analytical procedures are prerequisites for certifying GMP. Therefore, the aim of this study was to propose an authentication process for isolated ginsenosides $Rb_1$ and $Rg_1$ as reference materials (RM) and for these compounds to be designated as RMs for ginseng preparations throughout the world. Ginsenoside $Rb_1$ and $Rg_1$ were isolated by Diaion HP-20 adsorption chromatography, silica gel flash chromatography, recrystallization, and preparative HPLC. HPLC fractions corresponding to those two ginsenosides were recrystallized in appropriate solvents for the analysis of physico-chemical properties. Documentation of the isolated ginsenosides was made according to the method proposed by Gaedcke and Steinhoff. The ginsenosides were subjected to analyses of their general characteristics, identification, purity, content quantitation, and mass balance tests. The isolated ginsenosides were proven to be a single compound when analyzed by three different HPLC systems. Also, the water content was found to be 0.940% for $Rb_1$ and 0.485% for $Rg_1$, meaning that the net mass balance for ginsenoside $Rb_1$ and $Rg_1$ were 99.060% and 99.515%, respectively. From these results, we could assess and propose a full spectrum of physicochemical properties for the ginsenosides $Rb_1$ and $Rg_1$ as standard reference materials for GMP-based quality control.

Performance Improvement of Robust Speaker Verification According to Various Standard Deviations of a Reference Distribution in Histogram Transformation (히스토그램 변환에서 기준분포의 표준편차 변경에 따른 강인한 화자인증 성능 개선)

  • Kwon, Chul-Hong
    • Phonetics and Speech Sciences
    • /
    • v.2 no.3
    • /
    • pp.127-134
    • /
    • 2010
  • Additive noise and channel mismatch strongly degrade the performance of speaker verification systems, as they distort the features of speech. In this paper a histogram transformation technique is presented to improve the robustness of text-independent speaker verification systems. The technique transforms the features extracted from speech such that their histogram is conformed to a reference distribution. The effect of different standard deviations for the reference distribution is investigated. Experimental results indicate that, in channel mismatched environments, the proposed technique offers significant improvements over existing techniques. We also verify performance improvement of the proposed method using statistics.

  • PDF