• Title/Summary/Keyword: imprecision

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Tracking Control of 3-Wheels Omni-Directional Mobile Robot Using Fuzzy Azimuth Estimator (퍼지 방위각 추정기를 이용한 세 개의 전 방향 바퀴 구조의 이동로봇시스템의 개발)

  • Kim, Sang-Dae;Kim, Seung-Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.10
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    • pp.3873-3879
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    • 2010
  • Home service robot are not working in the fixed task such as industrial robot, because they are together with human in the same indoor space, but have to do in much more flexible and various environments. Most of them are developed on the base of the wheel-base mobile robot in the same method as a vehicle robot for factory automation. In these days, for holonomic system characteristics, omni-directional wheels are used in the mobile robot. A holonomicrobot, using omni-directional wheels, is capable of driving in any direction. But trajectory control for omni-directional mobile robot is not easy. Especially, azimuth control which sensor uncertainty problem is included is much more difficult. This paper develops trajectory controller of 3-wheels omni-directional mobile robot using fuzzy azimuth estimator. A trajectory controller for an omni-directional mobile robot, which each motor is controlled by an individual PID law to follow the speed command from inverse kinematics, needs a precise sensing data of its azimuth and exact estimation of reference azimuth value. It has imprecision and uncertainty inherent to perception sensors for azimuth. In this paper, they are solved by using fuzzy logic inference which can be used straightforward to perform the control of the mobile robot by means of the fuzzy behavior-based scheme already existent in literature. Finally, the good performance of the developed mobile robot is confirmed through live tests of path control task.

Nephrotoxicity Assessment by Determination of Urinary ${\gamma}$-Glutamyltranspeptidase ( ${\gamma}$-GTP) and N-Acetyl-$\beta$-D-Gluosa- minidase (AGS) in Rat (Rat에서 뇨중 ${\gamma}$-Glutamyltranspeptidase와 N-Acetyl-$\beta$-D-glucosaminidase 측정에 의한 신독성 평가에 관하여)

  • Kim Young-Ho;Lee Chang-Woo
    • Journal of Veterinary Clinics
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    • v.7 no.2
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    • pp.471-487
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    • 1990
  • Present experiment was performed in order to establish the optimum conditions for quantitation of ${\gamma}$-GTP and AGS activities in rat urine and investigate the applicability of the these enzymes in experimental assessment of nephrotoxicity in rats. The results obtained were as follows. 1. The optimal pH of Tris-BCI buffer containing glycylglycine for determination of urinary ${\gamma}$-GTP activity was 7.6(37$^{\circ}C$). 2. The Michaelis constant of urinary ${\gamma}$-GTP ranged from 1.1 to 1.2 mmol/$\ell$. 3. The optimal pH of citrate buffer for determination of urinary AGS activity was 3.6(37$^{\circ}C$). 4. The Michaelis constant of urinary AGS ranged from 0.8 to 0.9mmo1/$\ell$. 5. Coefficient of variance for within-run imprecision of urinary ${\gamma}$-GTP ranged from 3.8 to 6.4% and that of urinary AGS ranged from 2.5 to 4.1%. 6. There was no significant difference between gel-filtered samples and crude samples in the mean activity of urinary ${\gamma}$-GTP and the intra-individual differences by gel-filtration were either increased or decreased. Mean values of ${\gamma}$ -GTP activities in gel-filtered samples and crude samples were 1570 and 1590 U/$\ell$, repectively. 7. The mean activity of urinary AGS increased significantly after gel-filtration and all the individual urines revealed higher activities after gel-filtration. 8. ${\gamma}$-GTP and AGS activities were linear to 135 and 7U/$\ell$, respectively. 9. Urinary ${\gamma}$-GTP and AGS excretion before administration of potassium dichromate were 22.1 ${\pm}$ 11.2 and 0.5${\pm}$0.2 U/24hrsㆍkg body weight respectively and increased significantly to 102.3${\pm}$44.5 and 5.8${\pm}$3.30/24hrsㆍkg body weight respectively within 24 hours after administration. 10. BUN increased continuously from 24 hours following exposure to potassium dichromate in all 10 rats. From these findings it is concluded that the urinary ${\gamma}$-GTP and AGS excretions are early and sensitive indicators for nephrotoxicity assessment in rat.

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Usefulness of the $UBC^{TM}$ (Urinary Bladder Cancer) Test Compared to Urinary Cytology for Transitional Cell Carcinoma of the Bladder in Patients with Hematuria (혈뇨 환자의 방광암 진단에서 $UBC^{TM}$ (Urinary Bladder Cancer) 검사의 유용성)

  • Gil, Myung-Cheol;Kang, Do-Young;Seong, Youl-Koon;Jung, Se-Il;Kwon, Hyon-Young;Jung, Gyung-Woo;Kim, Duk-Kyu;Roh, Mee-Sook;Hwang, Tae-Ho;Yoon, Jin-Han
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.3
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    • pp.192-197
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    • 2001
  • Purpose: Urinary cytology and cystoscopic exam are effective methods for diagnosis of transitional cell carcinoma(TCC). But the former shows drawbacks such as the need for a well-trained examiner, and wide imprecision related to the variability of microscopic exam; the latter is an invasive method. $UBC^{TM}$ test detects the epitope on specific cytokeratin fragments released from epithelium of bladder cancer by immunoradiometric assay. We compared $UBC^{TM}$ test with urinary cytology for diagnosis of TCC to evaluate the utility of $UBC^{TM}$ test. Materials and Methods: Eighty-four patients with hematuria were included in our study. $UBC^{TM}$ tests (IDL Biotech, Sweden) were assayed in mid-stream urine according to the ordinary assay protocol. Nineteen patients were confirmed as TCC by cystoscopic examination and underwent transurethral resection (Group A). Other patients had various benign urinary tract conditions (Group B). Samples were considered positive as the $UBC^{TM}$ concentration was greater than $12{\mu}g/L$. Results: $UBC^{TM}$ levels were significantly different between group A ($95.9{\pm}166.4\;{\mu}g/L$) and group B ($19.2{\pm}85.6{\mu}g/L$) (P<0.001). Sensitivity for diagnosis of TCC was 89.5% (17/19) in UBC test and 47.4% (9/19) in cytology (p<0.05). Specificity for diagnosis of TCC was 81.5% (53/65) in $UBC^{TM}$ test and 100% (65/65) in cytology. $UBC^{TM}$ test was significantly more sensitive in stage Ta, $T_1$ tumors (84.6 vs 38.5%, p<0.05) and in grade I (83.3% vs 16.7%, p<0.05) than cytology. $UBC^{TM}$ test showed a tendency to be more sensitive as the grade was higher (83.3% in Grade I, 90% in Grade II and 100% in Grade III). Conclusion: $UBC^{TM}$ test could be a useful method in distinguishing TCC from other benign genitourinary diseases. Moreover, $UBC^{TM}$ test could be an especially valuable marker for diagnosis of TCC in patients with early TCC of low grade TCC compared to urinary cytology. Therefore, mbined use of $UBC^{TM}$ test in association with cytology is helpful to overcome the limited sensitivity of cytology.

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