• Title/Summary/Keyword: Measurement methods

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Severity Measurement Methods and Comparing Hospital Death Rates for Coronary Artery Bypass Graft Surgery (관상동맥우회술의 중증도 측정과 병원 사망률 비교에 관한 연구)

  • Ahn, Hyung-Sik;Shin, Young-Soo;Kwon, Young-Dae
    • Journal of Preventive Medicine and Public Health
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    • v.34 no.3
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    • pp.244-252
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    • 2001
  • Objective : Health insurers and policy makers are increasingly examining the hospital mortality rate as an indicator of hospital quality and performance. To be meaningful, a risk-adjustment of the death rates must be implemented. This study reviewed 5 severity measurement methods and applied them to the same data set to determine whether judgments regarding the severity-adjusted hospital mortality rates were sensitive to the specific severity measure. Methods : The medical records of 584 patients who underwent coronary artery bypass graft surgery in 6 general hospitals during 1996 and 1997 were reviewed by trained nurses. The MedisGroups, Disease Staging, Computerized Severity Index, APACHE III and KDRG were used to quantify severity of the patients. The predictive probability of death was calculated for each patient in the sample from a multivariate logistic regression model including the severity score, age and sex to evaluate the hospitals' performance, the ratio of the observed number of deaths to the expected number for each hospital was calculated. Results : The overall in-hospital mortality rate was 7.0%, ranging from 2.7% to 15.7% depending on the particular hospital. After the severity adjustment, the mortality rates for each hospital showed little difference according to the severity measure. The 5 severity measurement methods varied in their statistical performance. All had a higher c statistic and $R^2$ than the model containing only age and sex. There was a little difference in the relative hospital performance evaluation by the severity measure. Conclusion : These results suggest that judgments regarding a hospital's performance based on severity adjusted mortality can be sensitive to the severity measurement method. Although the 5 severity measures regarding hospital performance concurred, more often than would be expected by chance, the assessment of an individual hospital mortality rates varied by the different severity measurement method used.

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Inter-comparison of Accuracy of Discharge Measurement Methods - A Case Study Performed in the Dalcheon River Downstream of the Goesan Dam- (유량측정 방법의 정확도 분석 -괴산댐 하류 달천 적용 사례를 중심으로-)

  • Lee, Chan-Joo;Kim, Dong-Gu;Kwon, Sung-Il;Kim, Won
    • Journal of Korea Water Resources Association
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    • v.43 no.12
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    • pp.1039-1050
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    • 2010
  • Relative accuracy of six discharge measurement methods-velocity-area method, rod-float method, ADCP moving-vessel method, ADCP fixed-vessel method, electromagnetic wave surface velocimeter (EWSV), LSPIV- is evaluated by comparing discharges measured by them with dam released discharges. Data from 39 times of concurrent discharge measurement campaigns are analyzed. Except the rod-float method, measured discharges show absolute errors less than 6.2% with dam discharges. When the four methods is evaluated by being compared with discharges measured with the conventional velocity-area method, discharges with electromagnetic wave surface velocimetry shows 7.35% of absolute errors and other three methods shows absolute errors less than 6%. The rod-float method, which shows large discrepancy compared with dam and velocity-area method, need complementary verification.

A Framework for Quality Dimensions Measurement of Context Information (상황정보의 품질요소 측정 프레임워크)

  • Kim, Young-Hee;Lee, Keum-Suk
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.6 s.44
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    • pp.201-210
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    • 2006
  • This study proposed a framework to clarify a viewpoint of quality problems, and to consider reliance, of context information in ubiquitous computing environments. The framework is structured as a sequence of steps in measuring the quality of context information. The first step in measuring the qualify of context information is to determine users of the context information. This is important because the type of users or applications determines the type of context information and thus the methods of measuring the qualify dimensions and the thresholds for evaluating the quality of context information. The other steps include methods for measuring each quality dimensions to allow quantitative evaluation of quality, establishing acceptable quality targets. We selected accuracy, completeness, up-to-dateness, access security, and representation as quality dimensions and proposed their measurement methods and concrete procedures. We enabled objective evaluation of quality level through proposal of methods suitable to quality measurement of context information.

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Nerve length measurement method in a radial motor nerve conduction study

  • Kim, Jae-Gyum;Kim, Yoohwan;Seok, Hung Youl;Kim, Byung-Jo
    • Annals of Clinical Neurophysiology
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    • v.19 no.1
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    • pp.28-33
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    • 2017
  • Background: Previous studies of radial nerve conduction study (NCS) did not present how to measure the length of the radial nerve across the elbow, and did not even mention how to manage the spiral course of the nerve. This study aimed to applicate the most reliable method to measure the length of the radial nerve during NCS. Methods: Three points (A, B, and C) were determined along the relatively straight course of the radial nerve. The distance was measured using three different methods: L1) straight distance corresponding to the A-C distance, L2) sum of the distances corresponding to the A-B-C distance, L3) based on the L2, but the elbow is flexed at a $45^{\circ}$ angle. We compared the three methods of distance measurement and the calculated nerve conduction velocities (V1, V2, and V3) in normal healthy subjects. Results: 19 normal participants were enrolled. The mean value for method L1, L2 and L3 were $22.5{\pm}1.8cm$, $24.0{\pm}2.1cm$, and $23.2{\pm}2.1cm$ (p < 0.001). Calculated conduction velocities using those distance measurement methods as follows (p < 0.001): V1 ($60.9{\pm}2.7m/s$), V2 ($64.6{\pm}3.3m/s$), and V3 ($63.4{\pm}3.9m/s$). V2 was significantly greater than V1 and V3 (p < 0.001, p = 0.010, respectively). Conclusions: The distance measurement using a stopover point near the lateral epicondyle between two stimulus points in position of a fully extended elbow with forearm pronation is the most appropriate posture for radial motor NCS.

Non-intrusive measurement of pulse arrival time and Estimation of Systolic Blood Pressure (무구속적 맥파 전달 시간의 측정을 통한 혈압 추정)

  • Chee, Young-Joon;Park, Kwang-Suk
    • Proceedings of the IEEK Conference
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    • 2005.11a
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    • pp.489-492
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    • 2005
  • Even though the blood pressure is one of the most widely used index for the healthcare monitoring of hypertensive and normotensive persons, there is no non-intrusive measurement method which is commercialized until now. Pulse Arrival Time (PAT) is known that it has close relation with the systolic blood pressure (SBP) and arterial stiffness. In this study, SBP estimation methods by non-intrusive measurement of PAT are suggested. For the unconstrained measurement of PAT, the first method used the electrically non contact electrocardiogram (ENC-ECG) technique and the reflective type of Photoplethysmography (PPG) sensor on the computer mouse. In the second method, ENC-ECG and the air pressure sensor in the seat cushion on a chair were measured. The third method used ECG electrodes and PPG sensors on the toilet seat cover. The validation and regression analysis of the relationship of PAT and SBP are summarized. These methods have considerable errors to be used for all people. But these can be applied for each subject after the parameter customization within acceptable error. So, it is feasible for suggested methods to be used for monitoring of SBP in daily life in non-intrusive way when there is personal identification system of each subject.

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A Comparison Study Between International Standard and Statistical Analysis on LED Package Life (국제표준과 통계적 분석을 통한 LED Package 수명 비교 연구)

  • Park, Se Il;Kim, Gun So;Kim, Chung Hyeok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.31 no.2
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    • pp.122-127
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    • 2018
  • In an attempt to estimate the life projection of LED packages, IESNA published a paper regarding an LED package measurement test method in 2008, and a life projection technical document in 2011, to be used for LED life estimation. IESNA's publications regarding LED package measurement methods were functional, but they were not internationally standardized before 2017. In order to develop a standardized method, the International Standard chose to use the LM-80 as a measurement method for LED life projection in their publication in 2017. Many projection methods have been discussed by the IEC Technical Committee 34 working group, including the method using an exponential function, which reflects lumen degradation characteristics well. This study is designed to explore alternative LED package life estimation methods using an exponential function with statistical analysis, other than the one suggested by the International Standard.

Basic Study on Conditions and Analytical Methods of Biofilm Formation for the Bioassessment of Artificial Groundwater Recharge System (지하수 인공함양시스템의 생물학적 평가를 위한 생물막 형성 조건 및 형성도 분석 방법에 관한 기초연구)

  • Kong, In Chul;Lee, So Ra;Ha, Kyoochul;Ko, Kyung-Seok
    • Journal of Soil and Groundwater Environment
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    • v.20 no.4
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    • pp.22-30
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    • 2015
  • For the preliminary investigations of the bioclogging on groundwater artificial recharge system, studies for conditions and analytical methods of biofilm formation on sediments were performed. Based on the tested results, following conditions were determined for biofilm formation on batch process: optimum period for biofilm formation (30 days), the proper inoculating water (pond water), medium (minimum salt medium with 0.1% yeast extract). Procedures for the measurement of ATP and DHA were also determined. Biomass extract was used for ATP measurement, while sediment itself for DHA. Effects of metals on the biofilm formation were investigated under the determined conditions. Different sensitivities and orders were found depending on tested metals and measurement methods. In general, biomass measurement by ATP and viable cell count showed higher sensitivity than that of DHA. Following toxicity orders were also appeared for ATP and viable cell: Cu ≈ Cd > As(III).

Comparisons of Measurement Methods of the Moisture Content of Dried Vegetables (건조채소(乾燥菜蔬)의 수분측정방법(水分測定方法) 비교(比較))

  • Kwon, C.S.;Lee, D.S.
    • Journal of Biosystems Engineering
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    • v.12 no.1
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    • pp.39-44
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    • 1987
  • Measurement methods of moisture content were compared with 7 dried vegetables (red pepper, onion, green onion, garlic, ginger, carrot and radish). The moisture contents of dried vegetables having different moisture contents were determined by atmospheric oven drying, infrared balance, vacuum oven and Karl Fisher methods. Vacuum oven and Karl Fisher methods gave the relatively agreed results and considered to give the accurate moisture content. Atmospheric oven drying and infrared balance methods resulted in higher moisture content than methods mentioned above, because of the thermal decomposition of solid. Calibration of the moisture data of atmospheric oven drying method into the vacuum oven data was undertaken. The thermodecomposable solid fraction was high in onion, radish, green onion and carrot, and was in the range of 8.0-11.7% of the total solid in these products.

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A Comparative Analysis of Test Methods of Measuring d- and q-Axes Inductances for Interior Permanent Magnet Synchronous Motor (매입형 영구자석 동기전동기의 인덕턴스 측정법 비교 분석)

  • Kim, Seung-Joo;Kim, Cherl-Jin;Lee, Ju
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.58 no.5
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    • pp.923-928
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    • 2009
  • The performance analysis and robust control of the interior permanent magnet synchronous motor(IPMSM) greatly depend on accurate value of its parameters. To achieve the high performance of torque control, it is necessary to consider exact inductance values because the inductances are nonlinear parameters of operating the IPMSM. Therefore many different methods have been performed for analysis of the methodology for the exact measurement of synchronous inductances. None of them is considered standard, and accuracy levels of all these methods are also not consistent. Among these experimental methods, the DC current decay test and the vector current control test are ideal for a laboratory environment. In this paper, these two test methods are compared by applying inductances to the IPMSM. The paper analyzes the measured inductances of the two methods and their differences with inductances obtained from the finite element method(FEM).

A Study of Object Recognition for the Efficient Management of Construction Equipment

  • Hyeok-Jun Ryu;Suk-Won Lee;Ju-Hyung Kim;Jae-Jun Kim
    • International conference on construction engineering and project management
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    • 2013.01a
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    • pp.587-591
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    • 2013
  • Measuring the process of construction operations for productivity improvement remains a difficult task for most construction companies due to the manual effort required in most activity measurement methods. There are many ways to measuring the process. But past measurement methods was inefficient. Because they needed a lot of manpower and time. So, this article focus on the vision-based object recognition and tracking methods for automated construction. These methods have the advantage of efficient that human intervention was reduced. Therefore, this article is analyzed the performance of vision-based methods in the construction sites and is expected to contribute to selection of vision-based methods.

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