• Title/Summary/Keyword: $x^2-test$

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Seed Variability Test by 2,3,5-Triphenyltetrazolium Chloride (염화(鹽化)트리페닐테트라졸륨에 의(依)한 종자활력검정(種子活力檢定)에 관(關)한 연구(硏究))

  • Kim, Sam-Sik
    • Journal of Korean Society of Forest Science
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    • v.26 no.1
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    • pp.23-30
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    • 1975
  • To elucidate the dependability of seed variability determination by tetrazolium, 15 tree species were checked. For the comparison of potential germinability for these tree seeds, x-ray photography and routine germination test in a incubator were implemented. Though there were considerable differences of seed variability in percentage between germination test and tetrazolium test, the judgement by tetrazolium test and x-ray test gave similar results. These findings indicated that tetrazolium test is a reliable method if treated and inferred properly. Solution of 0.25 percent tetrazolium could give a complete colour reaction as well as 0.50 percent solution.

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Verification of Validity of MPM II for Neurological Patients in Intensive Care Units (신경계중환자의 사망예측모델(Mortality Probability Model II)에 대한 타당도 검증)

  • Kim, Hee-Jeong;Kim, Kyung-Hee
    • Journal of Korean Academy of Nursing
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    • v.41 no.1
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    • pp.92-100
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    • 2011
  • Purpose: Mortality Provability Model (MPM) II is a model for predicting mortality probability of patients admitted to ICU. This study was done to test the validity of MPM II for critically ill neurological patients and to determine applicability of MPM II in predicting mortality of neurological ICU patients. Methods: Data were collected from medical records of 187 neurological patients over 18 yr of age who were admitted to the ICU of C University Hospital during the period from January 2008 to May 2009. Collected data were analyzed through $X^2$ test, t-test, Mann-Whiteny test, goodness of fit test, and ROC curve. Results: As to mortality according to patients' general and clinically related characteristics, mortality was statistically significantly different for ICU stay, hospital stay, APACHE III score, APACHE predicted death rate, GCS, endotracheal intubation, and central venous catheter. Results of Hosmer-Lemeshow goodness-of-fit test were MPM $II_0$ ($X^2$=0.02, p=.989), MPM $II_24$ ($X^2$=0.99 p=.805), MPM $II_48$ ($X^2$=0.91, p=.822), and MPM $II_72$ ($X^2$=1.57, p=.457), and results of the discrimination test using the ROC curve were MPM $II_0$, .726 (p<.001), MPM $II_24$, .764 (p<.001), MPM $II_48$, .762 (p<.001), and MPM $II_72$, .809 (p<.001). Conclusion: MPM II was found to be a valid mortality prediction model for neurological ICU patients.

Modal Analysis and FEA of a Compressor Motor for 120Hz Resonance Reducing (컴프레서용 모터 120Hz 공진 저감을 위한 연구)

  • Shin, Hyun-Jang
    • Transactions of the KSME C: Technology and Education
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    • v.5 no.2
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    • pp.81-87
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    • 2017
  • 315Fr compressor motor exceeds vibration specifications. To find the reason, first a modal impact test with free-free condition is done. Second a modal test with fixed condition is done. Thereafter the test results are compared with FEM simulation results. Using free-free condition modal impact test, FEM simulation conditions (boundary, mesh..) are modified. The motor has rolling motion around 120Hz. FEM simulation also shows same result. FEM simulation will be used to develop other series compressor motors. Using this, manufacturing test model and doing test will be useless.

Study of the Optimal Calcination Temperature of an Al/Co/Ni Mixed Metal Oxide as a DeNOx Catalyst for LNT

  • Jang, Kil Nam;Han, Kwang Seon;Hong, Ji Sook;You, Young-Woo;Suh, Jeong Kwon;Hwang, Taek Sung
    • Clean Technology
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    • v.21 no.3
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    • pp.184-190
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    • 2015
  • Most of LNT catalysts use noble metals such as Pt for low temperature NOx oxidation but there is an economic weakness. For the purpose of overcoming this, this study is to develop DeNOx catalyst for LNT excluding PGM (platinum group metal) such as Pt, Pd, Rh, etc. To do so, Al/Co/Ni catalyst selected as a preliminary test is used to study fundamental property and NOx’s conversion according to calcined temperature. Ultimately, that is, Al/Co/Ni mixed metal oxide which does not use PGM is selected and physicochemical characterization is performed by way of XRD, EDS, SEM, BET and ramp test and NOx conversion is also analyzed. This study shows that all samples consist of mixed oxides of spinel structure of Co2AlO4 and NiAl2O4 and have enough pore volume and size for redox. But as a result of NH3-TPD test, it is desired that calcined temperature needs to be maintained at 700 ℃ or lower. Also only samples which are processed under 500 ℃ satisfied NO and NOx conversion simultaneously through ramp test. Based on this study’s results, optimum calcined temperature for Al/Co/Ni=1.0/2.5/0.3 mixed metal oxide catalyst is 500 ℃.

Statistical Analysis of Bioequivalence Study in 2x3 Cross-over Design

  • Lim, Nam-Kyoo
    • Communications for Statistical Applications and Methods
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    • v.8 no.2
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    • pp.443-452
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    • 2001
  • The 2x3 cross-over design is proposed for the bioequivalence of two test drug formulations with a reference drug formulation. Oh et al.(1999) and Park et al.(1998) derived 3x2 cross-over design and discussed its benefits, since the 3x3 cross-over design may not be of practical design. We discuss the statistical issues for2x3 cross-over design and show its statistical properties. Bioequivalence problem in 2x3 cross-over design is considered statistically and an illustrated example is given.

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An analysis of Factorial structure of Kinematic variables in Bowling (볼링의 운동학적 분석과 주요인 구조분석)

  • Lee, Kyung-Il
    • Korean Journal of Applied Biomechanics
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    • v.12 no.2
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    • pp.381-392
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    • 2002
  • This study attempted to indentify changeability of the factorial structure of kinematic analysis in bowling. Subjects of group composed of three groups : Higher bowers who are national representative bowers with 200 average point and one pro-bowler. Middle bowlers who are three common persons with 170 average points. Lower bowler who are three common persons with 150 average points. Motion analysis on throw motion in three groups respectively has been made through three-dimension cinematography using DLT method. Two high-speed video camera at operating 180 and 60 frame per secondary. T-test factorial structure analysis has been used to define variable relations. It was concluded that : 1. The difference of x1, x2, x4, x8, x9, x11, x12, x13 where significant between two group. 2. The difference of number of spin and angle of the back-hand where statistically significant between two group(p<.001, p<.05) 3. The correlation over r=.5 between the kinematic data x1, x2, x3, x9, x10, x11. In the rotation loading matrix Factor 1 was x1, x2, x9, x10 and Factor 2 relates to x3, x11. 4. In order to obtain the factor score as follow as ; Factor 1 = (0.248)X1 + (0.265)X2 + (-0.074)X3 + (0.259)X9 + (0.259)X10 + (-0.025)X11 Factor 2=(-0.016)X1 + (-0.055)X2 + (0.84)X3 + (-0.013)X9 + (-0.007)X10 + (0.553)X11.

Microstructure characterization technique of spacer garter spring coil X-750 material (스페이서 가터 스프링 코일 X-750 소재 정밀 조직 분석 방법)

  • Hyung-Ha Jin;I Seol Ryu;Gyeng-Geun Lee
    • Transactions of the Korean Society of Pressure Vessels and Piping
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    • v.17 no.2
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    • pp.109-118
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    • 2021
  • In the periodic surveillance material test for the spacer component of fuel channel assembly in CANDU, a microstructural characterization analysis is required in addition to the mechanical property evaluation test. In this study, detailed microstructure analysis and simple mechanical property evaluation of archive spacer parts were conducted to indirectly support the surveillance test and assist in the study of spacer material degradation. We investigated the microstructural characteristics of the spacer garter spring coil through comparative analysis with the plate material. The main microstructure characteristics of the garter spring coil X-750 are represented by the fine grain size distribution, the ordering phase distribution developed inside the matrix, the high dislocation density inside the grains, and the arrangement of coarse carbides. In addition, the yield strength of the garter spring coil X-750 was indirectly evaluated to be approximately 1 GPa. We also established an analytical method to elucidate the microstructural evolution of the radioactive spacer garter spring coil X-750 based on Canadian research experiences. Finally, we confirmed the measurement technique for helium bubble formation through TEM examination on the helium implanted X-750 material.

Adhesion and Diffusion Barrier Properties of $TaN_x$ Films between Cu and $SiO_2$ (Cu 박막과 $SiO_2$ 절연막사이의 $TaN_x$ 박막의 접착 및 확산방지 특성)

  • Kim, Yong-Chul;Lee, Do-Seon;Lee, Won-Jong
    • Journal of the Microelectronics and Packaging Society
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    • v.16 no.3
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    • pp.19-24
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    • 2009
  • Formation of an adhesion/barrier layer and a seed layer by sputtering techniques followed by electroplating has been one of the most widely used methods for the filling of through-Si via (TSV) with high aspect ratio for 3-D packaging. In this research, the adhesion and diffusion-barrier properties of the $TaN_x$ film deposited by reactive sputtering were investigated. The adhesion strength between Cu film and $SiO_2$/Si substrate was quantitatively measured by $180^{\circ}$ peel test and topple test as a function of the composition of the adhesive $TaN_x$ film. As the nitrogen content increased in the adhesive $TaN_x$ film, the adhesion strength between Cu and $SiO_2$/Si substrate increased, which was attributed to the increased formation of interfacial compound layer with the nitrogen flow rate. We also examined the diffusion-barrier properties of the $TaN_x$ films against Cu diffusion and found that it was improved with increasing nitrogen content in the $TaN_x$ film up to N/Ta ratio of 1.4.

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Simplification of One Step Immunotech AFP Test (AFP 검사방법 단축에 관한 고찰)

  • Moon, Ki Choon;Kwon, Won Hyun;Kim, Jung In;Lee, In Won
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.1
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    • pp.80-84
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    • 2013
  • Purpose: The Immunotech AFP is a widely used test in 14 hospitals(RIA QC establishments: 46) as a liver tumor marker. Normally, the test takes 45 minutes including complicated 2 step method. We evaluated the possibility of 1 step method and suitable test time. Materials and Methods: Samples of 31 patients in SNUBH were used as subject. We evaluated the sensitivity, intra and inter assay precision, recovery rate, linearity between 1 step and 2 step method (45 min. and 60 min.). Results: Both of 45 minutes and 60 minutes test showed 0.1 ng/mL sensitivity. In 45 minutes test, the intra assay coefficients of variation were 3.05%, 3.43%, 1.68%. Also, inter assay coefficients of variation were 3.91%, 2.38%, 0.82%. In 60 minutes test, the intra assay were 5.00%, 3.69%, 1.97%, inter assay were 3.14%, 3.71%, 1.85%.The correlation coefficient of each 2 step and 1 step (45 min.), 2 step and 1 step(60 min.), 1 step (45 min.) and 1 step (60 min.) were y=0.9293x+2.7356 ($R^{2}=0.9999$), y=0.9193x+4.1002 ($R^{2}=0.9993$), y=0.9894x+1.3805 ($R^{2}=0.9997$). Conclusion: Compared 1step method to 2 step method, both method showed very reasonable precision, recovery rate and correlation coefficient. Also, 1 step method(45 min.) of correlation coefficient ($R^2$) was 0.999. We suggest that 1 step method test can reduce the test time and is useful for AFP test.

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Reliability Verification of Secured V2X Communication for Cooperative Automated Driving (자율협력주행을 위한 V2X 보안통신의 신뢰성 검증)

  • Jung, Han-gyun;Lim, Ki-taeg;Shin, Dae-kyo;Yoon, Sang-hun;Jin, Seong-keun;Jang, Soo-hyun;Kwak, Jae-min
    • Journal of Advanced Navigation Technology
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    • v.22 no.5
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    • pp.391-399
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    • 2018
  • V2X communication is a technology in which a vehicle exchanges information with various entities such as other vehicles, infrastructure, networks, pedestrians, etc. through a wired or wireless network. Recently, V2X communication technology has been steadily developed and recently it has played an important role in autonomous cooperation driving technology combined with autonomous vehicle technology. Autonomous vehicles can utilize the external information received via V2X communication to extend the recognition range of existing sensors and to support more safe and natural autonomous driving. In order to operate these autonomous cooperative vehicles on public roads, the security and reliability of autonomous V2X communication should be verified in advance. In this paper, we present test scenarios and test procedures of secure V2X communication for cooperative automated driving and present verification results.