• Title/Summary/Keyword: reliability sensitivity

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Application and Efficacy Evaluation of Nutritional Screening Tool (영양부족 환자의 조기발견을 위한 선별검사의 적용 및 효용성 평가)

  • Nam, Gung-Hwan
    • Journal of Korea Association of Health Promotion
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    • v.4 no.1
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    • pp.1-11
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    • 2006
  • "본 논문은 대한외과학회지 2006년 제70권제1호에 실렸던 논문으로 대한외과학회 편집위원회 승인을 득하고 본 협회지에 게재함. Purpose: Malnutrition has been frequently reported for patients on their admission to the hospital and it has been associated with an increase in morbidity, mortality and the length of the hospital stay. Although a number of screening tools have been developed to identify those patients at risk for malnutrition, there is no' gold standard' for defining malnutrition and the malnourished patients remain largely unrecognized. The aim of this study is to evaluate the efficacy of a nutritional screening tool for use in Dankook University Hospital. Methods Nutritional evaluation was performed for 53 patients who were admitted to the department of surgery and internal medicine between October and December 2004. The screening tool was completed by the ward nurse and the nutritional support team nurse on the same patients within24 hours of admission. The nutritional support team nurse performed the full assessment. The screening sheet included 4 questions regarding body mass index, recent unintentional weight loss, food intake and disease severity. Each answer was scored and a total of 5 was tested as the criterion fey malnutrition. The full assessment included current body weight, recent weight loss, triceps skinfold thickness, mid-arm muscle circumference, serum albumin)in and total lymphocyte count. Malnutrition was defined by 3 or more values below the reference values. The reliability of the screening tool was assessed using kappa statistic. Sensitivity, specificity and accuracy were calculated to evaluate the validity of the screening tool. The receiver operating characteristic(ROC) curve was drawn to choose a cutoff valve that maximizes sensitivity and specificity. Results' The level of agreement between the ward nurse and the NST nurse was good for BMI and food intake and moderate for weight loss and disease severity. The full assessment identified7 patients(13.2%) as malnourished. The screening sheet had a sensitivity of 86% and a specificity of 80%. According to the ROC curve, a score of 5 points provided the best validity. Conclusion The nutritional screening tool is reliable when completed by different observers and it is valid for nutritional assessment.

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Design, Fabricaiton and Testing of a Piezoresistive Cantilever-Beam Microaccelerometer for Automotive Airbag Applications (에어백용 압저항형 외팔보 미소 가속도계의 설계, 제작 및 시험)

  • Ko, Jong-Soo;Cho, Young-Ho;Kwak, Byung-Man;Park, Kwan-Hum
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.2
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    • pp.408-413
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    • 1996
  • A self-diagnostic, air-damped, piezoresitive, cantilever-beam microaccelerometer has been designed, fabricated and tested for applications to automotive electronic airbag systems. A skew-symmetric proof-mass has been designed for self-diagnostic capability and zero transverse sensitivity. Two kinds of multi-step anisotropic etching processes are developed for beam thickness control and fillet-rounding formation, UV-curing paste has been used for sillicon-to-glass bounding. The resonant frequency of 2.07kHz has been measured from the fabricated devices. The sensitivity of 195 $\mu{V}$/g is obtained with a nonlinearity of 4% over $\pm$50g ranges. Flat amplitude response and frequency-proportional phase response have been obserbed, It is shown that the design and fabricaiton methods developed in the present study yield a simple, practical and effective mean for improving the performance, reliability as well as the reproducibility of the accelerometers.

A Study on Aircraft Sensitivity Analysis for Supersonic Air-Data Error at Low Altitude (공기정보 오차에 의한 저고도 초음속 영역에서의 민감도 해석에 관한 연구)

  • Kim, Chong-Sup;Hwang, Byung-Moon;Kim, Seong-Youl;Kim, Seong-Jun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.33 no.11
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    • pp.80-87
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    • 2005
  • T-50 supersonic jet trainer aircraft using digital flight-by-wire flight control system receives aircraft flight conditions such as altitude, VCAS(Calibrated Airspeed) and Angle of Attack from IMFP(Integrated Multi-Function Probe). IMFP sensors information have triplex structure using three IMFP sensors. Air-data selection logic is mid-value selection in three information from three IMFP sensors in order to have more reliability. From supersonic flight test at high altitude, air-data information is dropped simultaneously because of supersonic shock wave effect. This error information may affect to aircraft stability and safety in supersonic area at low altitude. This paper propose that sensitivity analysis and HQS(Handling Quality Simulator) pilot simulation in order to analyze flight stability and controllability in supersonic area at low altitude when these information is applied to flight control law.

Assessment of Equine Temperament by a Questionnaire Survey (Questionnaire Survey를 이용한 말의 품성 평가)

  • Kim, Nam-Young;Park, Yong-Sang;Ko, Moon-Suck;Chae, Hyun-Seok;Cho, Won-Mo;Cho, In-Chul;Hong, Hyun-Ju;Park, Ji-Yun;Chung, Kwang-Yeoun;Cho, Sang-Rae
    • Journal of Embryo Transfer
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    • v.28 no.3
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    • pp.223-227
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    • 2013
  • The objective of the study is to assess temperament of a horse based on general temperament test by a questionnaire survey. Five test criteria were identified: gentleness, patience, aggressiveness, sensitivity, and friendliness, each on a 5-point scale. 114 horses bred at the National Institute of Animal Science (NIAS) in 2010, 2011 and 2012. The horses recorded scores of 3.6~3.9 for gentleness, 3.1~3.6 for patience, 3.4~4.0 for aggressiveness, 2.8~3.2 for sensitivity, and 3.4~3.8 for friendliness, the overall score for sensitivity the lowest. Horses born in 2012 scored lower than the rest in all five areas at a statistically significant level (P<0.05). By gender, the colts scored higher than the fillies in all five areas, but the discrepancy was not statistically significant. Factor analysis yielded only one factor, and the Cronbach's ${\alpha}$ value was 0.980 for standardization of Factor 1, indicating a high reliability of internal consistency. The correlation coefficients among the test criteria ranged between 0.85 and 0.91 (P<0.01). The assessment criteria used in this study are expected to provide a useful basis designing a temperament test horses.

Feasibility Study of AASHTO86 Design Method for Bonded Concrete Overlay (AASHTO86 접착식 콘크리트 덧씌우기 설계법의 타당성 연구)

  • Park, Jong Won;Kim, Young Kyu;Han, Seung Hwan;Lee, Seung Woo
    • International Journal of Highway Engineering
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    • v.15 no.2
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    • pp.47-55
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    • 2013
  • PURPOSES : This study aimed to evaluate the feasibility of AASHTO86 design method for Bonded Concrete Overlay. METHODS : The Feasibility of AASHTO86 design method for Bonded Concrete Overlay is investigated based on the following study : i) Sensitivity analysis of designed service life of Bonded Concrete Overlay by major design input for AASHTO86 guide. ii) Comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life by AASHTO86. iii) Finding the stress component influence the potential distress of Bonded Concrete Overlay based on 3-d FEM analysis. iv) Exploring the limitation of AASHTO86 in the aspect of design input. RESULTS : Sensitivity analysis showed that the condition of existing pavement significantly on the Bonded Concrete Overlay life. Also the overlay thickness affect the Bonded Concrete Overlay life. The comparison of actual Bonded Concrete Overlay life and predicted Bonded Concrete Overlay life showed relatively good agreement when the early distress sections are excluded in comparison. Bonding stress occurred at the interface may be larger than the bond strength used in the specification of Bonded Concrete Overlay construction. CONCLUSIONS : Bonded Concrete Overlay life predicted by the AASHTO86 may not be reliable. Number of points to improve the reliability in the design of Bonded Concrete Overlay are suggested in this study.

A study on the Development of Smoke Detector Sensitivity Test Equipment (휴대용 연기감도시험기 개발에 관한 연구)

  • Kim, Hyeong-Gweon;Kwon, Seong-Pil;Yoon, Hun-Ju;SaKong, Seong-Ho
    • Fire Science and Engineering
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    • v.23 no.5
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    • pp.125-132
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    • 2009
  • In this study we could contribute to the development of a precise checking tool with which the reliability of the automatic fire detection systems was enhanced and the safety of the people was ensured. In the same way as the domestic technical standard, the portable smoke sensitivity tester, which was developed in this work, could be used to check the capability of the smoke detectors installed in the field. Its heater inside was warmed up to $400^{\circ}C$ in 40 seconds and the paper as a smoke source was burned to produce smoke for the test. With the Photoelectric smoke detector it was possible to measure and control the smoke concentration in a range from 0%/m to 25%/m. With the adjustment of rpm of the fan, it was possible to keep a constant wind velocity in a range from 20cm/sec to 40cm/sec.

Analysis of Low Frequency Noise Variation in Temperature Sensor With Bi2Mg2/3Nb4/3O7 (Bi2Mg2/3Nb4/3O7을 사용한 온도센서의 저주파 잡음 특성)

  • Cho, Il Hwan;Seo, Dongsun
    • Journal of IKEEE
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    • v.19 no.4
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    • pp.486-490
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    • 2015
  • Sensitivity characteristics of temperature sensor with $Bi_2Mg_{2/3}Nb_{4/3}O_7$ (BMNO) layer were investigated with low frequency noise measurement. Temperature sensor with BMNO layer had high reliability and high sensitivity comparing with conventional MOS type temperature sensor. Annealing temperature variation effects with $600^{\circ}C$, $700^{\circ}C$ and $800^{\circ}C$ were measured and analyzed. Annealing temperature determines trap distribution and $700^{\circ}C$ annealing sample has different pattern comparing with other samples. Results of low frequency noise can offer the design guide of temperature sensor performance.

Screening Tool for Anxiety Disorders: Development and Validation of the Korean Anxiety Screening Assessment

  • Kim, Yeseul;Park, Yeonsoo;Cho, Gyeongcheol;Park, Kiho;Kim, Shin-Hyang;Baik, Seung Yeon;Kim, Cho Long;Jung, Sooyun;Lee, Won-Hye;Choi, Younyoung;Lee, Seung-Hwan;Choi, Kee-Hong
    • Psychiatry investigation
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    • v.15 no.11
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    • pp.1053-1063
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    • 2018
  • Objective This study evaluated the psychometric properties of the Korean Anxiety Screening Assessment (K-ANX) developed for screening anxiety disorders. Methods Data from 613 participants were analyzed. The K-ANX was evaluated for reliability using Cronbach's alpha, item-total correlation, and test information curve, and for validity using focus group interviews, factor analysis, correlational analysis, and item characteristics based on item response theory (IRT). The diagnostic sensitivity and specificity of the K-ANX were compared with those of the Beck Anxiety Inventory (BAI) and Generalized Anxiety Disorder 7-item scale (GAD-7). Results The K-ANX showed excellent internal consistency (${\alpha}=0.97$) and item-total coefficients (0.92-0.97), and a one-factor structure was suggested. All items were highly correlated with the total scores of the BAI, GAD-7, and Penn State Worry Questionnaire. IRT analysis indicated the K-ANX was most informative as a screening tool for anxiety disorders at the range between 0.8 and 1.6 (i.e., top 21.2 to 5.5 percentiles). Higher sensitivity (0.795) and specificity (0.937) for identifying anxiety disorders were observed in the K-ANX compared to the BAI and GAD-7. Conclusion The K-ANX is a reliable and valid measure to screen anxiety disorders in a Korean sample, with greater sensitivity and specificity than current measures of anxiety symptoms.

Fabrication of Pt/Carbon Nanotube Composite Based Electrochemical Hydrogen Sulfide Gas Sensor using 3D Printing (3D 프린팅을 이용한 Pt/Carbon Nanotube composite 기반 전기화학식 황화수소 가스 센서 제작)

  • Yuntae Ha;JinBeom Kwon;Suji Choi;Daewoong Jung
    • Journal of Sensor Science and Technology
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    • v.32 no.5
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    • pp.290-294
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    • 2023
  • Among various types of harmful gases, hydrogen sulfide is a strong toxic gas that is mainly generated during spillage and wastewater treatment at industrial sites. Hydrogen sulfide can irritate the conjunctiva even at low concentrations of less than 10 ppm, cause coughing, paralysis of smell and respiratory failure at a concentration of 100 ppm, and coma and permanent brain loss at concentrations above 1000 ppm. Therefore, rapid detection of hydrogen sulfide among harmful gases is extremely important for our safety, health, and comfortable living environment. Most hydrogen sulfide gas sensors that have been reported are electrical resistive metal oxide-based semiconductor gas sensors that are easy to manufacture and mass-produce and have the advantage of high sensitivity; however, they have low gas selectivity. In contrast, the electrochemical sensor measures the concentration of hydrogen sulfide using an electrochemical reaction between hydrogen sulfide, an electrode, and an electrolyte. Electrochemical sensors have various advantages, including sensitivity, selectivity, fast response time, and the ability to measure room temperature. However, most electrochemical hydrogen sulfide gas sensors depend on imports. Although domestic technologies and products exist, more research is required on their long-term stability and reliability. Therefore, this study includes the processes from electrode material synthesis to sensor fabrication and characteristic evaluation, and introduces the sensor structure design and material selection to improve the sensitivity and selectivity of the sensor. A sensor case was fabricated using a 3D printer, and an Ag reference electrode, and a Pt counter electrode were deposited and applied to a Polytetrafluoroethylene (PTFE) filter using PVD. The working electrode was also deposited on a PTFE filter using vacuum filtration, and an electrochemical hydrogen sulfide gas sensor capable of measuring concentrations as low as 0.6 ppm was developed.

A Reliability Analysis of Slope Stability of Earth-Rockfill Dam (Earth-Rockfill Dam사면파괴에 대한 신뢰도 연구(I))

  • 박현종;이인모
    • Geotechnical Engineering
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    • v.7 no.3
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    • pp.21-32
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    • 1991
  • The purpose of this paper is to develop a reliability model for slope stability of Earth-rockfill dams which accounts for all uncertainties encountered. The uncertain factors of the design variables include the cohesion, the angle of internal friction, and the porewater Pressure in each zone. More specifically, the model errors in estimating those variables are studied in depth. To reduce the uncertainties due to model errors, updated design variables are obtained using Bayesian Theory. For stability analysis, both the two-dimesional stability analysis and the three-dimensional stability analysis where the end effects and the system reliability concept are considered are used for the reliability calculations. The deterministic safety factor by the three-dimensional analysis is lager than that by the two-dimensional anlysis. However, the probability of failure by the three-dimensional analysis is about 3.5 times larger that by the two-dimensional analysis. It is because the system reliability concept is used in the three-dimensional analysis. The sensitivity analysis shows that the probability of failure is more sensitive to the uncertainty of the cohesion than that of the angle of internal friction.

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