• Journal of the Korean Operations Research and Management Science Society
• /
• v.21 no.3
• /
• pp.159-174
• /
• 1996

Facing decision-making tasks, managers frequently make judgments, However, since managers are human beings, the fficiency of their judgments is limited. Two major sources of inefficiency in their judgments have been recognized : one is systematic deviations from normatively preferred decisions, so called bias or incorrect intuition, and the other is inconsistency in their judgments, i. e. erratic decision making variance. Rather than bias, variance is really expensive or damaging. Thus, if the inconsistency inmanagers judgments is removed, performance could be by far improved by virtue of the reduced random variance. One of the approaches to improve managerial judgment is to simply bring managers together by effectively moderating the random variance due to inconsistency. Focusing on combining judgments, this paper addresses many relevant issues such as why combining and how to combine judgments, and suggests methods and models to effectively aggregate subjective judgments, We conduct an experiment to validata the effectiveness of combining jugements over individual judgments. Various combining schemes are also evaluated in terms of their prective accuracy. Among them, mean bias based wighting scheme turns out the best. However, when available information is not enough to estimate the expertise of judges, simple and robust equal weighting might be more efficient and productive. This urges an imperative future research on the issue of how many and which ones to combine from a large set of experts.

• Proceedings of the Korea Contents Association Conference
• /
• 2005.11a
• /
• pp.649-653
• /
• 2005

To estimate for an error signal with sigmoid nonlinearity what reduced constellation applies closed eye pattern in the initial equalization, there can be improves problems of previous soft decision-directed algorithm that increasing estimate complexity and decreasing of convergence speed when substitute high-order constellation. The characteristic of sigmoid function is adjusted by a mean and a variance parameter, so it depends on adjustment of variance that what reduced constellation $values(\gamma)$ can have ranges between + $\gamma$ and - $\gamma$. In this paper, we proposed Variable Modulus Algorithm (VMA) that can be improving a performance of steady-state by adjustment of variance when equalization works normally and each cluster of constellation decrease.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.39 no.8
• /
• pp.689-701
• /
• 2011

The relations between ambient conditions and ice accretion shapes are quantitatively analyzed by employing self-organization maps and analysis of variance. Liquid water contents(LWC), mean volumetric droplet diameter(MVD), ambient temperature and free-stream velocity are chosen as ambient conditions which change ice accretion shapes. The parameters of ice accretion shape are selected as maximum thickness, icing limits, ice heading, and ice accretion area. Qualitative analysis was conducted by employing self-organization maps which show the qualitative relations between ice shapes and ambient conditions. The quantitative results of analysis of variance yield intensity of ambient conditions to the parameters of ice accretion shapes.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.32 no.4
• /
• pp.184-191
• /
• 2009

In a technological driven environment, a depreciation estimate which is based on traditional life analysis results in a decelerated rate of capital recovery. This time pattern of technological growths models needs to be incorporated into life analysis framework especially in those industries experiencing fast technological changes. The approximation technique for calculating the variance can be applied to the six growth models that were selected by the degree of skewness and the transformation of the functions. For the Pearl growth model, the Gompertz growth model, and the Weibull growth model, the errors have zero mean and a constant variance over time. However, transformed models like the linearized Fisher-Pry model, the linearized Gompertz growth model, and the linearized Weibull growth model have increasing variance from zero to that point at which inflection occurs. It can be recommended that if the variance of error over time is increasing, then a transformation of observed data is appropriate.

• Journal of Korean Academy of Fundamentals of Nursing
• /
• v.14 no.1
• /
• pp.92-102
• /
• 2007

Purpose: This study was conducted to evaluate nutritional status, and the effects of lifestyles and depression on nutritional status of elderly people (NSE). Method: The participants were 280 elders who visited the Y city Senior Welfare Center between August 2006 and October 2006. Data were collected using a structured questionnaire that included general characteristics, lifestyle checklist, depression scale, and nutritional risk index. Also, Body Mass Index (BMI) was calculated from height and weight. T-test, ANOVA, Duncan test, Pearson coefficients correlation and stepwise multiple regression were used to analyze the data using the SPSS Win 12.0 program. Results: The NSE mean score was mid level at 5.03 BMI was 23.42 which indicates overweight. Depression was the factor that influenced the nutritional risk index most strongly, accounting for 17.3% of the total variance in the NSE. A combination of significance of health, concerns about health, housing, condition of teeth, activity, and smoking pattern accounted for 29.8% of the variance in the NSE. Condition of teeth accounted for only 3.8% of the variance in BMI. Conclusion: It is necessary to be aware that variance in the NSE can be affected by several factors including depression and lifestyle and that depression is strongly related to poorer NSE.

• Journal of Korean Society for Quality Management
• /
• v.29 no.1
• /
• pp.1-10
• /
• 2001

We consider the problem of detecting special variations in multivariate $T^2$-control chart when two or more multivariate outliers are present. Since a multivariate outlier may reflect slippage in mean, variance, or correlation, it can distort the sample mean vector and sample covariance matrix. Damaged sample mean vector and sample covariance matrix have difficulty in examining special variations clearly, An alternative to detection outliers or special variations is to use robust estimators of mean vector and covariance matrix that are less sensitive to extreme observations than are the standard estimators $\bar{x}$ and $\textbf{S}$. We applied popular minimum volume ellipsoid(MVE) and minimum covariance determinant(MCD) method to estimate mean vector and covariance matrix and compared its results with standard $T^2$-control chart using simulated multivariate data with outliers. We found that the modified $T^2$-control chart based on the above robust methods were more effective in detecting special variations clearly than the standard $T^2$-control chart.

• Journal of Pharmaceutical Investigation
• /
• v.2 no.2
• /
• pp.18-33
• /
• 1972

Pharmaceutical Study on the Compressed tablets. Hardness, Friability, Disintegration time and Coefficient of Variance of Compressed tablets. Soo Uck Kim, Sung Hoon seo and Hyun Woo Lee (Department of Pharmaceutics, College of Pharmacy, Kyung Hee University) In order to know Hardness, Friability, Disintegration time and Coefficient of variance of the pharmaceutical tablets the 135 tablets sampled from market were tested in the paper. The samples tested in this paper were as follows: Antipyretics and Analgetics 41 Stomach and Digestives 22 Antituberculars 19 Vitamins 12 Sulfa drugs 9 Others (Antihistaminics etc) 32 Total 135 The results of the investigation are shown in table 1-8, Fig 1-Fig 6. Mean values of Hardness, Friability, Disintegration time and Coefficient of variance in each pharmaceutical preparation are as follows. Antipyretics and Analgetics : Hardness(kg) = 5.83 Antipyretics and Analgetics : Friabil.(%) = 0.82 Antipyretics and Analgetics : Disint.t.(min) = 5.28' Antipyretics and Analgetics : Coeff. of V.(%) = 2.90 Stomach and Digestives : Hardness(kg) = 4.11 Stomach and Digestives : Friabil.(%) = 0.71 Stomach and Digestives : Disint.t.(min) = 3.43' Stomach and Digestives : Coeff. of V.(%) = 2.76 Antituberculars : Hardness(kg) = 4.78 Antituberculars : Friabil.(%) = 0.52 Antituberculars : Disint.t.(min) = 4.32' Antituberculars : Coeff. of V.(%) = 2.99 Vitamins : Hardness(kg) = 1.60 Vitamins : Friabil.(%) = 0.43 Vitamins : Disint.t.(min) = 4.10' Vitamins : Coeff. of V.(%) = 3.19 Sulfa drugs : Hardness(kg) = 4.77 Sulfa drugs : Friabil.(%) = 0.37 Sulfa drugs : Disint.t.(min) = 3.10' Sulfa drugs : Coeff. of V.(%) = 2.09 Others : Hardness(kg) = 2.40 Others : Friabil.(%) = 0.66 Others : Disint.t.(min) = 2.19' Others : Coeff. of V.(%) = 3.10 The following summeries might be shown; 1. Ranges of Hardness, Friability, Disintegration time and Coefficient of variance are respectively 1.6 to 5.38 kg, 0.37 to 0.82%, 2 minut 19 second to 5 minut 28 second and 2.09 to 3.10%. 2. According to the results, it could be indicated that higher Hardness shows lower Friability. 3. Against the general conception between Hardness and Disintegration time, higher Hardness shows lower Disintegration time. 4. It seems that higher mean weight shows lowcr Coefficient variance.

• Korean journal of applied entomology
• /
• v.51 no.2
• /
• pp.91-97
• /
• 2012

The dispersion indices, spatial pattern and sampling plan for pink citrus rust mite (PCRM), Aculops pelekassi, monitoring was investigated. Dispersion indices of PCRM indicated the aggregated spatial pattern. Taylor's power law provided better description of variance-mean relationship than Iwao's patchiness regression. Fixed-precision levels (D) of a sequential sampling plan were developed using by Taylor's power law parameters generated from PCRM on fruit sample (cumulated number of PCRM in $cm^2$ of fruit). Based on Kono-Sugino's empirical binomial the mean density per $cm^2$ could be estimated from fruit ratio with more than 12 rust mites per $cm^2$: $ln(m)=4.61+1.23ln[-ln(1-p_{12})]$. To determine the optimal tally threshold, the variance (var(lnm)) for mean (lnm) in Kono-Sugino equation was estimated. The lower and narrow ranged change of variance for esimated mean showed at a tally threshold of 12. To estimate PCRM mean density per $cm^2$ at fixed precision level 0.25, the required sample number was 13 trees, 5 fruits per tree and 2 points per fruit (total 130 samples).

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.5
• /
• pp.3378-3384
• /
• 2015

The problem of fast search for raman spectrum has attracted much attention recently. By far the most simple and widely used method is to calculate and compare the Euclidean distance between the given spectrum and the spectra in a database. But it is non-trivial problem because of the inherent high dimensionality of the data. One of the most serious problems is the high computational complexity of searching for the closet codeword. To overcome this problem, The fast codeword search algorithm based on the mean pyramids of codewords is currently used in image coding applications. In this paper, we present three new methods for the fast algorithm to search for the closet codeword. the proposed algorithm uses two significant features of a vector, mean values and variance, to reject many unlikely codewords and save a great deal of computation time. The Experiment results show about 42.8-55.2% performance improvement for the 1DMPS+PDS. The results obtained confirm the effectiveness of the proposed algorithm.

• Journal of the Korean Statistical Society
• /
• v.30 no.1
• /
• pp.77-87
• /
• 2001

Some asymptotic results on the local likelihood density estimator of Copas(1995) are derived when the locally parametric model has several parameters. It turns out that it has the same asymptotic mean squared error as that of Hjort and Jones(1996).