• Title/Summary/Keyword: new test method

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A NEW CPT-BASED METHOD FOR UNDRAINED SHEAR STRENGTH ESTIMATION OF CLAYS

  • Lee, Jun-Hwan
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.09c
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    • pp.18-23
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    • 2010
  • The estimation of the undrained shear strength $s_u$ for clays using CPT results has been mainly based on the cone factor $N_k$. In this study, a new CPT-based method for the estimation of the undrained shear strength $s_u$ is presented. This aims at reducing uncertainties for the estimation of $s_u$ and enhancing the application of CPT results in more effective manner. For this purpose, a site located at a marine clay deposit is selected and test results from extensive experimental testing program are adopted. The new method defines a direct correlation between the undrained shear strength $s_u$ and the cone resistance $q_t$, excluding the procedure of the overburden pressure correction and therefore undisturbed soil sampling process. In order to verify the new CPT-based method, additional test sites and example sites from literature, which consist of a variety of soil conditions, are selected and examined. It is observed that values of su obtained from the proposed method are in good agreements with measured values of $s_u$ for all the selected verification cases.

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A Study of Borehole Thermal Behavior with 1-Dimensional Model;Field Test Analysis included (1차원 모델에 의한 보어홀 열거동 해석 및 현지측정)

  • Kim, Dae-Ki;Woo, Joung-Son;Ro, Jeong-Geun;Lee, Se-Kyoun
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.11a
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    • pp.550-554
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    • 2007
  • A one-dimensional heat transfer model coupled with parameter estimation is developed in this study to predict the effective thermal conductivities of soil formation and borehole resistances from in situ field test data. In this application a new method of using initial ignoring time(IIT) obtained from error estimation is tried and turned out to be successful in determining soil thermal conductivities. The validity of this model is accomplished through comparison of the predicted temperature profiles of the model with the data from laboratory scale experimental setting. Eleven test boreholes were constructed in Ochang, Chungcheong Buk Do, and thermal response test was carried out with each borehole. The results of the in situ tests were analyzed with our 1-D numerical model and compared with the results of line source method. The comparison shows that the thermal properties from line source method is a little lower (${\sim}95%$)than those from numerical method. The reason of such result seems to be the lower thermal conductivity of grout material, which is not counted in line source method.

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Ultrasonic Test Criterion for the Explosively Welded Fe-Naval Brass Bonding Quality (초음파법에 의한 폭발접합 이종금속 접합품질 판정레벨 설정에 관한 연구)

  • 장영권;백영남
    • Journal of Welding and Joining
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    • v.19 no.1
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    • pp.40-48
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    • 2001
  • An ultrasonic test method, as a nondestructive test is applied to ensure the clad interface quality assessment. According to the reference codes and standards, not only korea Industrial Standard(KS) but also American Society for Testing and Materials (ASTM) Standard, ultrasonic examination procedures use the pulse-echo, A-scan, back reflection signal drop method and/or side drilled reference hole used to establish the acceptance criteria of clad material test. But the variety of bonding materials and sizes makes it difficult to produce the reference blocks, or thus the criteria. In order to overcome these practical difficulties, new ultrasonic testing criterion is suggested. In this new method, the theoretical interface reflection signal amplitude level is calculated and suggested as an acceptance criteria with the back reflection signal set to 100% FSH(Full Screen Height) which is based on acoustic impedance mismatch at the clad interface for the explosive clad ultrasonic inspection. Applicability of suggested criterion, for the explosive clad Fe-Naval Brass with different bonding quality is confirmed to the pre-existed KS and ASTM specifications and verified by using SEM (Seanning Electron Microscope) micrograph. The results obtained by the suggested method is more conservative than the results according to the KS B 0234 and ASTM A 578 specifications The suggested method could be applicable to any other combination of explosive clad ultrasonic inspection.

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Numerical simulation and experimental investigation of the shear mechanical behaviors of non-persistent joint in new shear test condition

  • Wang, Dandan;Zhang, Guang;Sarfarazi, Vahab;Haeri, Hadi;Naderi, A.A.
    • Computers and Concrete
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    • v.26 no.3
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    • pp.239-255
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    • 2020
  • Experimental and discrete element method were used to investigate the effects of joint number and its angularities on the shear behaviour of joint's bridge area. A new shear test condition was used to model the gypsum cracks under shear loading. Gypsum samples with dimension of 120 mm×100 mm×50 mm were prepared. the length of joints was 2cm. in experimental tests, the joint number is 1, 2 and 3 and its angularities change from 0° to 90° with increment of 45°. Assuming a plane strain condition, special rectangular models are prepared with dimension of 120 mm×100 mm. similar to joints configuration in experimental test, 9 models with different joint number and joint angularities were prepared. This testing show that the failure process is mostly governed by the joint number and joint angularities. The shear strengths of the specimens are related to the fracture pattern and failure mechanism of the discontinuities. The shear behaviour of discontinuities is related to the number of induced tensile cracks which are increased by increasing the rock bridge length. The strength of samples decreases by increasing the joint number and joint angularities. Failure pattern and failure strength are similar in both of the experimental test and numerical simulation.

A Study of Restricted Cervical Rotation Test; in the View of Manual Muscle Test (경추회전제한검사법에 대한 소고; 근육검사법 관점에서)

  • Ahn, Seong-Hun;Lee, Young-Jun;Sohn, In-Chul
    • Journal of TMJ Balancing Medicine
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    • v.2 no.1
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    • pp.8-12
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    • 2012
  • Objectives: It has been reported to continue that temporomandibular joint balancing medicine (functional cerebrospinal therapy; FCST) is effective in treating incurable diseases in clinic recently. FCST is based on the results of restricted cervical rotation test, it means that the results of restricted cervical rotation test has a very high reliability on test results. Methods: This study has the aim to understand restricted cervical rotation test method and to use well with high technical skill. So manual muscle test method which was based on the upper limb lifting resistance test method are compared with restricted cervical rotation test method and had been discussed. Results: Results are that restricted cervical rotation test by using the passive motion of arrested persons (patients) have high the reliability and accuracy. Conclusions: It is concluded that restricted cervical rotation test is the new type of manual muscle tests and the results of test are very high the reliability and accuracy so that the acquirement of test method is helpful in clinic practically.

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A study on the testing method of discolored tap water by spectrophotometer (분광측색계에 의한 착색 수돗물 시험방법 연구)

  • Dongheon Kim;Jonggeum Lee;Jiyoon Oh;Gitae Kim;Hangbae Jun
    • Journal of Korean Society of Water and Wastewater
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    • v.37 no.4
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    • pp.187-202
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    • 2023
  • This study focuses on the application of a new measurement method that quantifies the residual color of filtered water using a spectrocolorimeter after filtering the discolored substances. It was confirmed through the color and turbidity cross-test that the discolored substances cannot be measured effectively with the current legal color and turbidity test method. Therefore, the National Institute of Environmental Research's filter testing method, which involves filtering the sample through 0.45 ㎛ filter and visually inspecting the color, was improved. A membrane filter colorimetry (MFC) method was established by measuring the color difference (ΔE*ab(65)) of the filtered filter using a spectrophotometer and expressing it as filter color unit (FCU). Using the MFC method, the FCU for reference materials such as iron and manganese, as well as field samples, was measured. The results showed a high correlation with turbidity, and the color difference patterns varied depending on the type of reference materials and field samples. This indicates that the MFC method is an effective new measurement method of discolored tap water.

Verification Method to Detect the Fake Test Data in Military Supplies (군수업체 시험 데이터 및 시험 시스템 유효성 점검을 위한 제언)

  • Chung, Ilhan;Joo, Jinchun;Kim, Sunggon;Cho, Hyeonghwan;Ahn, Namsu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.3
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    • pp.231-240
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    • 2016
  • Recently, fake test data of power cables in nuclear power plants was a terrible shock to the citizens. Some cable companies manipulated the test data to make unfair profits. In addition, fake test data cases were found in military supplies. The fake test data cases focused on parts of army's tank, armored car. This paper propose a new method that can detect fake test data using known statistical methods. In addition, the method was implemented in Microsoft Excel to allow easy use. Lastly, a check sheet was proposed to check the validity of the test system of military suppliers. By detecting and checking the fake test data, it is expected that our new method will play an important role in quality assurance of military supplies.

Goodness-of-fit test for the gumbel distribution based on the generalized Lorenz curve (일반화된 로렌츠 곡선을 기반으로 한 Gumbel 분포의 적합도 검정)

  • Lee, Kyeongjun
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.4
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    • pp.733-742
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    • 2017
  • There are many areas of applications where Gumbel distribution are employed such as environmental sciences, system reliability and hydrology. The goodness-of-fit test for Gumbel distribution is very important in environmental sciences, system reliability and hydrology data analysis. Therefore, we propose the two test statistics to test goodness-of-fit for the Gumbel distribution based on the generalized Lorenz curve. We compare the new test statistic with the Anderson - Darling test, Cramer - vonMises test, and modified Anderson - Darling test in terms of the power of the test through by Monte Carlo method. As a result, the new test statistics are more powerful than the other test statistics. Also, we propose new graphic method to goodness-of-fit test for the Gumbel distribution based on the generalized Lorenz curve.

Design of Keyword Extraction System Using TFIDF (TFIDF를 이용한 키워드 추출 시스템 설계)

  • 이말례;배환국
    • Korean Journal of Cognitive Science
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    • v.13 no.1
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    • pp.1-11
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    • 2002
  • In this paper, a test was performed to determine whether words in Anchor Text were appropriate as key words. As a result of the test. there were proper words of high weighting factor, while some others did not even appear in the text. therefore, were not appropriate as key words. In order to resolve this problem. a new method was proposed to extract key words. Using the proposed method, inappropriate key words can be removed so that new key words be set, and then, ranking becomes possible with the TFIDF value as a weighting factor of the key word. It was verified that the new method has higher accuracy compared to the previous methods.

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Hydraulic Efficiency measurement of small turbine and example of it's analysis (소수력수차의 효율측정과 분석사례)

  • Kim, Eung-Tae;Jung, Yong-Chea;Park, Jang-Won
    • 유체기계공업학회:학술대회논문집
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    • 2005.12a
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    • pp.748-756
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    • 2005
  • The Purpose of this writing is a presentation of small turbine efficiency measuring method, applicable new technology, and several analysis result for real turbine. Measurement methods of hydraulic efficiency written in here are extracted from small turbine applicable international code(IEC, ASME). It includes brief synopsis of 'Current meter method' and 4 other methods and ASFM as a new small turbine applicable technology. And several analysis of test result are for recently performed domestic small turbine result in korea. Through this presentation of extracted code, I hope that it make other small turbine concerner be familiar to perform an efficiency test. for small turbine. And, some analysis of that, make other to feel the importance of efficiency test.

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