• Title/Summary/Keyword: simple tests

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Comparison of Marine Insolation Estimating Methods in the Adriatic Sea

  • Byun, Do-Seong;Pinardi, Nadia
    • Ocean Science Journal
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    • v.42 no.4
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    • pp.211-222
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    • 2007
  • We compare insolation results calculated from two well-known empirical formulas (Socket and Beaudry's SB73 formula and the original Smithsonian (SMS) formula) and a radiative transfer model using input data predicted from meteorological weather-forecast models, and review the accuracy of each method. Comparison of annual mean daily irradiance values for clear-sky conditions between the two formulas shows that, relative to the SMS, the SB73 underestimates spring values by 9 W $m^{-2}$ in the northern Adriatic Sea, although overall there is a good agreement between the annual results calculated with the two formulas. We also elucidate the effect on SMS of changing the 'Sun-Earth distance factor (f)', a parameter which is commonly assumed to be constant in the oceanographic context. Results show that the mean daily solar radiation for clear-sky conditions in the northern Adriatic Sea can be reduced as much as 12 W $m^{-2}$ during summer due to a decrease in the f value. Lastly, surface irradiance values calculated from a simple radiative transfer model (GM02) for clear-sky conditions are compared to those from SB73 and SMS. Comparison with iu situ data in the northern Adriatic Sea shows that the GM02 estimate gives more realistic surface irradiance values than SMS, particularly during summer. Additionally, irradiance values calculated by GM02 using the buoy meteorological fields and ECMWF (The European Centre for Medium Range Weather Forecasts) meteorological data show the suitability of the ECMWF data usage. Through tests of GM02 sensitivity to key regional meteorological factors, we explore the main factors contributing significantly to a reduction in summertime solar irradiance in the Adriatic Sea.

Development of Lateral Flow Immunoassay for Antigen Detection in Human Angiostrongylus cantonensis Infection

  • Chen, Mu-Xin;Chen, Jia-Xu;Chen, Shao-Hong;Huang, Da-Na;Ai, Lin;Zhang, Ren-Li
    • Parasites, Hosts and Diseases
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    • v.54 no.3
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    • pp.375-380
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    • 2016
  • Angiostrongyliasis is difficult to be diagnosed for the reason that no ideal method can be used. Serologic tests require specific equipment and are not always available in poverty-stricken zone and are time-consuming. A lateral flow immunoassay (LFIA) may be useful for angiostrongyliasis control. We established a LFIA for the diagnosis of angiostrongyliasis based on 2 monoclonal antibodies (mAbs) against antigens of Angiostrongylus cantonensis adults. The sensitivity and specificity were 91.1% and 100% in LFIA, while those of commercial ELISA kit was 97.8% and 86.3%, respectively. Youden index was 0.91 in LFIA and 0.84 in commercial ELISA kit. LFIA showed detection limit of 1 ng/ml of A. cantonensis ES antigens. This LFIA was simple, rapid, highly sensitive and specific, which opened an alternative approach for the diagnosis of human angiostrongyliasis.

A Portmanteau Test Based on the Discrete Cosine Transform (이산코사인변환을 기반으로 한 포트맨토 검정)

  • Oh, Sung-Un;Cho, Hye-Min;Yeo, In-Kwon
    • The Korean Journal of Applied Statistics
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    • v.20 no.2
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    • pp.323-332
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    • 2007
  • We present a new type of portmanteau test in the frequency domain which is derived from the discrete cosine transform(DCT). For the stationary time series, DCT coefficients are asymptotically independent and their variances are expressed by linear combinations of autocovariances. The covariance matrix of DCT coefficients for white noises is diagonal matrix whose diagonal elements is the variance of time series. A simple way to test the independence of time series is that we divide DCT coefficients into two or three parts and then compare sample variances. We also do this by testing the slope in the linear regression model of which the response variables are absolute values or squares of coefficients. Simulation results show that the proposed tests has much higher powers than Ljung-Box test in most cases of our experiments.

Temperature and Strain Rate Dependent Tension Properties of Stainless Steel-Aluminum-Magnesium Multilayered Sheet Fabricated by Roll Bonding (롤 아연된 STS-Al-Mg 이종금속판재의 온도와 변형률속도에 따른 1축인장 변형특성)

  • Hwang, B.K.;Lee, K.S.;Hong, S.E.;Lee, Y.S.
    • Transactions of Materials Processing
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    • v.20 no.3
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    • pp.257-264
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    • 2011
  • Multilayer(clad) sheets, composed of two or more materials with different properties, are fabricated using the roll-bonding process. A good formability is an essential property for a multilayered sheet in order to manufacture parts by plastic deformation. In this study, the influences of temperature and strain rate on the plastic properties of stainless steel-aluminum-magnesium multilayered(STS-Al-Mg) sheets were investigated. Tensile tests were performed at various temperatures and strain rates on the multilayered sheet and on each separate layer. Fracture of the multilayered sheet was observed to be temperature-dependent. At the base temperature of $200^{\circ}C$, all materials fractured simultaneously. At lower temperatures, the Mg alloy sheet fractured earlier than the other materials. Conversely, the other materials fractured earlier than the Mg alloy sheet at higher temperatures. The uniform and total elongations of the multilayered sheet were observed to be higher than that of each material at a temperature of $250^{\circ}C$. Larger uniform elongations were obtained for higher strain rates at constant temperature. The same trend was observed for the Mg alloy sheet, which exhibited the lowest elongation among the three materials. The tensile strengths and elongations of the single layer sheets were compared to those of the multilayer material. The strength of the multilayered sheet was successfully calculated by the rule of mixture from the values of each single layer. However, no simple correlation between the elongation of each layer and that of the multilayer was obtained.

Evaluation of Material Properties of Concrete Harbour Facilities Using Nondestructive Testing Methods (비파괴시험에 의한 콘크리트 항만시설물의 주요 물성치 평가)

  • Yi, Jin-Hak;Han, Sang-Hun;Park, Woo-Sun
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.23 no.1
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    • pp.1-10
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    • 2011
  • Recently harbor remodeling projects are seriously considered to enhance the loading and unloading capability of old container terminals and to make decrepit ports as eco-friendly harbor and waterfront spaces in many countries. In such a case, quantitative and qualitative evaluations on concrete harbor facilities are mandatory to determine the current structural integrity condition of aged materials. Once the remodeling project is determined to be carried out, the reusability of individual structural members and facilities including caissons, cell-blocks, and tetra-pods need to be decided based on the simple and economic visual inspection and/or nondestructive testing. In this study, the systematic quantitative evaluation procedure for determining the structural integrity condition and the reusability is studied based the nondestructive testing and evaluation methods. Conventional methods including Schmidt hammer test and ultrasonicpulse velocity methods and elastic wave based methods including impact echo test and surface wave test are applied to the old harbor facilities in five different sites. The compressive tests are also carried out to determine the elastic modulus and compressive strength of concrete materials.

Comparisons of obesity assessments in over-weight elementary students using anthropometry, BIA, CT and DEXA

  • Yu, Ok-Kyeong;Rhee, Yang-Keun;Park, Tae-Sun;Cha, Youn-Soo
    • Nutrition Research and Practice
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    • v.4 no.2
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    • pp.128-135
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    • 2010
  • Obesity was characterized in Korean elementary students using different obesity assessment tests on 103 overweight elementary students from three schools of Jeonbuk Province. The body mass index (BMI) and obesity index (OI) were compared, and the data using DEXA and CT were compared with the data using BIA and a tape measure. The results of this study are as follows: first, 27 students who were classified as obese by OI were classified as overweight by BMI, and 3 students who were classified as standard weight by BMI were classified as overweight by OI. Secondly, by DEXA and BIA measurements, there was 1.51% difference in body fat percentage (boys 1.66%, girls 1.17%) and the difference in body fat mass between boys and girls was 0.77 kg (boys 0.85 kg, girls 0.59 kg), but those differences in body fat percentage and mass were not statistically significant. Thirdly, the average total abdominal fat (TAF) measured by CT scans of obese children was more significantly related with subcutaneous fat (r = 0.983, P < 0.01) than visceral fat (r = 0.640, P < 0.01). Also, TAF were highest significant with waist circumference by a tape measure (r = 0.744, P < 0.01). In summary, as there are some differences of assessment results between two obesity test methods (BMI, OI), we need more definite standards to determine the degree of obesity. The BIA seems to be the most simple and effective way to measure body fat mass, whereas waist/hip ratio (WHR) using a tape measurer is considered to be the most effective method for assessing abdominal fat in elementary students.

Effective Application of Multiplex RT-PCR for Characterization of Human Embryonic Stem Cells/ Induced Pluripotent Stem Cells (다중 역전사 중합효소 연쇄 반응(Multiplex RT-PCR)을 이용한 인간배아 줄기세포 및 유도만능 줄기세포의 효과적인 분화 양상 조사)

  • Kim, Jung-Mo;Cho, Youn-Jeong;Son, On-Ju;Hong, Ki-Sung;Chung, Hyung-Min
    • Reproductive and Developmental Biology
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    • v.35 no.1
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    • pp.1-8
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    • 2011
  • Techniques to evaluate gene expression profiling, such as sufficiently sensitive cDNA microarrays or real-time quantitative PCR, are efficient methods for monitoring human pluripotent stem cell (hESC/iPSC) cultures. However, most of these high-throughput tests have a limited use due to high cost, extended turn-around time, and the involvement of highly specialized technical expertise. Hence, there is an urgency of rapid, cost-effective, robust, yet sensitive method development for routine screening of hESCs/hiPSCs. A critical requirement in hESC/hiPSC cultures is to maintain a uniform undifferentiated state and to determine their differentiation capacity by showing the expression of gene markers representing all three germ layers, including ectoderm, mesoderm, and endoderm. To quantify the modulation of gene expression in hESCs/hiPSC during their propagation, expansion, and differentiation via embryoid body (EB) formation, we developed a simple, rapid, inexpensive, and definitive multimarker, semiquantitative multiplex RT-PCR platform technology. Among the 9 gene primers tested, 5 were pluripotent markers comprising set 1, and 3 lineage-specific markers were combined as set 2, respectively. We found that these 2 sets were not only effective in determining the relative differentiation in hESCs/hiPSCs, but were easily reproducible. In this study, we used the hES/hiPS cell lines to standardize the technique. This multiplex RT-PCR assay is flexible and, by selecting appropriate reporter genes, can be designed for characterization of different hESC/hiPSC lines during routine maintenance and directed differentiation.

Cumulative Angular Distortion Curve of Multi-Pass Welding at Thick Plate of Offshore Structures

  • Ha, Yunsok;Choi, Jiwon
    • Journal of Advanced Research in Ocean Engineering
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    • v.1 no.2
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    • pp.106-114
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    • 2015
  • In the fabrication of offshore oil and gas facilities, the significance of dimension control is growing continuously. But, it is difficult to determine the deformation of the structure during fabrication by simple lab tests due to the large size and the complicated shape. Strain-boundary method (a kind of shrinkage method) based on the shell element was proposed to predict the welding distortion of a structure effectively. Modeling of weld geometry in shell element is still a difficult task. In this paper, a concept of imaginary temperature pair is introduced to handle the effect of geometric factors such as groove shape, plate thickness and pass number, etc. Single pass imaginary temperature pair formula is derived from the relation between the groove area and the FE mesh size. By considering the contribution of each weld layer to the whole weldment, multi-pass imaginary temperature is also derived. Since the temperature difference represents the distortion increment, cumulative distortion curve can be drawn by integrating the temperature difference. This curve will be a useful solution when engineers meet some problems occurred in the shipyard. A typical example is shown about utilization of this curve. Several verifications are conducted to examine the validity of the proposed methodology. The applicability of the model is also demonstrated by applying it to the fabrication process of the heavy ship block. It is expected that the imaginary temperature model can effectively solve the modeling problem in shell element. It is also expected that the cumulative distortion curve derived from the imaginary temperature can offer useful qualitative information about angular distortion without FE analysis.

Investigation of Eye-Tracking on Learning Task Perceiving Process of Elementary Students with Different Motivation System on Science Learning (학습과제 인지 과정에 대한 과학학습 동기체계에 따른 초등학생의 시선이동 분석)

  • Yang, Il-Ho;Lim, Sung-Man;Kim, Yang-Hee
    • Journal of Korean Elementary Science Education
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    • v.34 no.1
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    • pp.86-94
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    • 2015
  • This study is to investigate how do elementary students' eye movements appear in cognitive process that they perceive science learning materials depending on motivation system of science learning. For this study we had a random sampling of 301, 6th grade students. And we had selected 32 students through the three tests for the final; motivation system test of science learning, a learning styles test, an Edinburgh inventory for handedness test. We were analysis the cognitive process during learning tasks for the selected student using eye-tracking equipment. The results of the research are as follows: First, when students see a science learning material, we found out that SL-BAS group that has tendency searched various areas than SL-BIS group in learning task. Second, results confirmed through the data of integrational count that students looked alternately texts, images and graphs in the learning material, SL-BIS group were more than SL-BAS group on integrated count, but they had a simple and insignificant eye movement. Especially SL-BAS students showed that integrated eye movement between texts, images and graphs in the learning material, and they explored important areas of the graph compared with SL-BIS group that there was no eye movement in graph. These results may be utilized as a useful resource for designing students' learning.

Interface for in-situ Authoring of Augmented Reality Contents on a Mobile Device Environment (모바일 환경 증강현실 콘텐츠 현장 저작 인터페이스)

  • Lee, Jeong-Gyu;Lee, Jong-Weon
    • The Journal of the Korea Contents Association
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    • v.10 no.7
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    • pp.1-9
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    • 2010
  • This paper introduces a difference between mobile Augmented Reality (AR) authoring and desktop AR authoring, and suggests an interface system that can be applied to in-situ authoring of AR contents on a mobile device. The mobile devices have enabled users to use the AR system anytime and anywhere. It is now necessary to create user's individualized context information using mobile devices on the spot. To author AR contents easily with mobile devices, we need to maximize the convenience of mobile systems, which have yet limitation. To do so, this paper suggests new interaction approaches that manage augmented contents using visual cues and other simple attribute settings. In addition, to solve the problem that users have to hold their mobile devices to track markers while authoring contents, this system enables users to author contents in environment based on captured images. This interface system also can make cooperation environment for more than one users to author contents. This paper verifies the usefulness of the proposed interface by user tests. The results of an analyzing users' comments show that the proposed interface is suitable for in-situ mobile authoring system.