• Title/Summary/Keyword: density function

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Effect of Nonnormality on Bayes Decision Function for Testing Normal Mean

  • Bansal, Ashok K.
    • Journal of the Korean Statistical Society
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    • v.8 no.1
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    • pp.15-21
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    • 1979
  • A zone of sensitivity is developed to investigate the effect of nonnormality on the Bayes decision function for testing mean of a normal population when either parent or prior belongs to Edgeworthian family of moderately nonnormal probability density functions.

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Recursive Parameter estimation algorithm of the Probability (확률밀도함수의 축차모수추정 방법)

  • 한영열;박진수
    • Proceedings of the Korean Institute of Communication Sciences Conference
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    • 1984.04a
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    • pp.42-45
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    • 1984
  • we propose a new parameter estimation algorithm that converge with probability one and in mean square, If the mean is the function of parameter of the probability density function. This recursive algorithm is applicable also ever the parameters we estimate are multiparameter case. And the results are shown by the computer simulation.

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THE BERGMAN KERNEL FUNCTION AND THE DENSITY THEOREMS IN THE PLANE

  • Jeong, Moonja
    • Bulletin of the Korean Mathematical Society
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    • v.31 no.1
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    • pp.115-123
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    • 1994
  • The Bergman kernel is closely connected to mapping problems in complex analysis. For example, the Riemann mapping function is witten down in terms of the Bergman kernel. Hence, information about the bergman kernel gives information about mappings. In this note, we prove the following theorem.

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Determinants of Reduced Bone Mass in Postmenopausal Women with Rheumatoid Arthritis (폐경 후 류마티스 관절염 여성의 골량감소 판별요인)

  • Lee, Eun-Nam
    • The Korean Journal of Rehabilitation Nursing
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    • v.2 no.2
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    • pp.193-205
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    • 1999
  • This study was carried out to identify the important risk factors for reduced bone mass of postmenopausal RA patients and to develop discriminant function which can classify postmenopausal RA patients with either reduced or normal bone mass. Through the literature review, individual characteristics such as age, body weight, height, age of menarche, duration of menopause, gravity, parity, and breast feeding period and factors of life style such as milk consumption exercise habit, alcohol intake, cigarette smoking, coffee consumpt ion , disease activity, corticosteroid therapy were identified as influencing factors of reduced bone mass in RA patients Sixty eight postmenopausal women with rheumatoid arthritis aged between 42 and 76 were selected among those who checked bone mineral density in lumbar spine and femur from october, 1998 to Apr il, 1999 at Dong-a university hospital in Pusan. Assessment of disease activity, duration of disease and corticosteroid therapy were made by the same rheumatologist and included Ritchie articular index, erythrocyte sedimentation rate, and C-reactive protein on measuring bone mineral density. Cumulative steroid dosage was calculated from the daily dosage multiplied by t h e number of days received. The information of other risk factor including health assessment score, individual characteristics and life style factors were collected by questionnaire. Bone mineral density(BMD) was measured using DXA at lumbar spine and femoral Ward's triangle. Discriminant function(regression equation) was developed for estimating the likelihood of the presence or absence of reduced bone mass. The results are as follows: Among the subjects, thirteen(19.1%) exhibited osteoporosis in lumbar spine and twenty four(35.3%) exhibited osteoporosis in femoral Ward's triangle. For lumbar spine, the variables significant were age, body weight, health assessment score, while for femoral Ward's triangle, age, body weight, duration of disease. But disease activity and corticosteroid therapy were not signigicant to distinguish reduced bone mass from normal bone mass. When the discriminant function was evaluated by comparing the observed out come with predicted out come, the discriminant function correctly classified 85.4% of patients with reduce bone mass and 63.0% of patients with normal bone mass in the lumbar spine and 100% of patients with reduced bone mass and 9.1% of patients with normal bone mass in the femoral Ward's triangle. In summary, we found that osteoporosis in postmenopausal women with RA is more evident at the femur than the lumbar spine. Also the important discriminant factors of reduced bone mass postmenopausal women with RA were age, body weight , duration of disease and health disability. In nursing situation, the efforts to improve of functional capacity of postmenopausal women with rheumatoid arthritis should be considered to prevent osteoporosis and fractures. Also we recommend those postmenopausal women with RA who are classified as a group of the reduced bone mass in the discriminant function should examine the bone mineral density to further examine the usefulness of this discriminant function.

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Effects of Omega-3 on Lipid and Liver Function Tests (Omega-3가 지질과 간기능검사에 미치는 영향)

  • Choi, Woo-Soon
    • Korean Journal of Clinical Laboratory Science
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    • v.50 no.2
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    • pp.183-189
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    • 2018
  • Omega-3 unsaturated fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are found in fish and fish oil. Recent studies have shown that omega-3 fatty acids are effective in cancer, cardiovascular disease, immune system, cirrhosis, and nervous system disorders. In particular, omega-3 was also reported to help improve hyperlipidemia and liver function tests. On the other hand, there are few cases in Korea. This study examined whether omega-3 is effective in improving hyperlipemia and liver function by taking 1 gm/day for 2 weeks. As a result, AST was decreased in the liver function test, and GGT related to alcoholic hepatitis and fatty liver showed significant results. Omega-3 has been shown to help improve the liver function. The triglyceride, total cholesterol, and low density cholesterol associated with cardiovascular disease decreased after omega-3 ingestion, particularly high density cholesterol. Omega-3 has also been shown to improve the hyperlipidemia. Comparisons between males and females before and after the ingestion of omega-3 showed significant results in AST (P<0.01) from the male group and in GGT (P<0.01) and high density cholesterol (P<0.01) from the female group. As a result, omega-3 intake can help control and improve liver function and hyperlipidemia.

ROC Function Estimation (ROC 함수 추정)

  • Hong, Chong-Sun;Lin, Mei Hua;Hong, Sun-Woo
    • The Korean Journal of Applied Statistics
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    • v.24 no.6
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    • pp.987-994
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    • 2011
  • From the point view of credit evaluation whose population is divided into the default and non-default state, two methods are considered to estimate conditional distribution functions: one is to estimate under the assumption that the data is followed the mixture normal distribution and the other is to use the kernel density estimation. The parameters of normal mixture are estimated using the EM algorithm. For the kernel density estimation, five kinds of well known kernel functions and four kinds of the bandwidths are explored. In addition, the corresponding ROC functions are obtained based on the estimated distribution functions. The goodness-of-fit of the estimated distribution functions are discussed and the performance of the ROC functions are compared. In this work, it is found that the kernel distribution functions shows better fit, and the ROC function obtained under the assumption of normal mixture shows better performance.

Autoencoder-Based Automotive Intrusion Detection System Using Gaussian Kernel Density Estimation Function (가우시안 커널 밀도 추정 함수를 이용한 오토인코더 기반 차량용 침입 탐지 시스템)

  • Donghyeon Kim;Hyungchul Im;Seongsoo Lee
    • Journal of IKEEE
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    • v.28 no.1
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    • pp.6-13
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    • 2024
  • This paper proposes an approach to detect abnormal data in automotive controller area network (CAN) using an unsupervised learning model, i.e. autoencoder and Gaussian kernel density estimation function. The proposed autoencoder model is trained with only message ID of CAN data frames. Afterwards, by employing the Gaussian kernel density estimation function, it effectively detects abnormal data based on the trained model characterized by the optimally determined number of frames and a loss threshold. It was verified and evaluated using four types of attack data, i.e. DoS attacks, gear spoofing attacks, RPM spoofing attacks, and fuzzy attacks. Compared with conventional unsupervised learning-based models, it has achieved over 99% detection performance across all evaluation metrics.

Productivity of the Flounder Stocking Density on the Flounder Culture Farms (넙치양식장 밀식에 따른 생산성에 관한 연구)

  • Eh, Youn-Yang
    • The Journal of Fisheries Business Administration
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    • v.42 no.2
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    • pp.85-96
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    • 2011
  • Oliver flounder population density affect Oliver flounder growth and mortality rate. In laboratory pilot experiment, Oliver flounder growth rate is inversely proportional to stocking density. But previous study has not proved external validity. This study is aimed to analyze the effect of stocking density on the Oliver flounder culture farms in Jeju Island. In order to do this, I selected 13 farms in Jeju island as a sample. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows. First, in case of the Oliver flounder culture farms, Bertalanffy equation is not applicable to the Oliver flounder growth. Second, the Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, is preferred to density definition defined as the weight of Oliver flounder per $m^2$ of water surface area on the Oliver Flounder Culture Farms case. Third, growth rate and production weight on the Oliver flounder culture farms are inversely proportional to stocking density on spearman rank correlation test. When extensive comparable biological and culture condition data become available, analysis model can be easily modified to yield more accurate results.

The Digital Image Processing Method Using Triple-Density Discrete Wavelet Transformation (3중 밀도 이산 웨이브렛 변환을 이용한 디지털 영상처리 기법)

  • Shin, Jong Hong
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.8 no.3
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    • pp.133-145
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    • 2012
  • This paper describes the high density discrete wavelet transformation which is one that expands an N point signal to M transform coefficients with M > N. The double-density discrete wavelet transform is one of the high density discrete wavelet transformation. This transformation employs one scaling function and two distinct wavelets, which are designed to be offset from one another by one half. And it is nearly shift-invariant. Similarly, triple-density discrete wavelet transformation is a new set of dyadic wavelet transformation with two generators. The construction provides a higher sampling in both time and frequency. Specifically, the spectrum of the first wavelet is concentrated halfway between the spectrum of the second wavelet and the spectrum of its dilated version. In addition, the second wavelet is translated by half-integers rather than whole-integers in the frame construction. This arrangement leads to high density wavelet transformation. But this new transform is approximately shift-invariant and has intermediate scales. In two dimensions, this transform outperforms the standard and double-density discrete wavelet transformation in terms of multiple directions. Resultingly, the proposed wavelet transformation services good performance in image and video processing fields.

Seam-Strength as a Function of Angle of Bias on the Patterns (의복패턴상에서 직물의 각도 변화에 따른 봉합강도)

  • 이명희;최석철
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.4
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    • pp.710-717
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    • 1997
  • An investigation made of fabric strength & elongation and the lock stitch seam strength & elongation by stitch density (N1.5; 26 stitches/3 cm, N2.0; 19 stitches/3 cm, N2.5; 14 stitches/3cm) depending on methods of. sample prepariation (angle variations of unseamed sample and overlapping way of seamed sample) It found maximum stitch density that results of the seam strength test was highist in each angle of bias. The results obstained were as follows: 1. As the results of fabric strength and elongation tests as a function of angle of bias, breaking strength were that warp and weft angles (0$^{\circ}$, 90$^{\circ}$) were much higher than bias angles (20$^{\circ}$, 30$^{\circ}$, 45$^{\circ}$, 60$^{\circ}$) . And otherwise breaking elongation were that 45$^{\circ}$ angle of bias were highest and were that the warp & weft way were lower. 2. As the results of the seam strength tests by the stitch density under samples of same angles, the maximum stitch density were those; under 0$^{\circ}$/0$^{\circ}$, 60$^{\circ}$/60$^{\circ}$:F1, F2-N2.0, F3-N1.5, under 20$^{\circ}$/20$^{\circ}$, 30$^{\circ}$/30$^{\circ}$, 45$^{\circ}$/45$^{\circ}$: F1-N2.5, F2-N2.0, F3-N1.5, under 90$^{\circ}$/90$^{\circ}$: F1, F2, F3-N1.5. 3. As the results of the seam strength tests by the stitch density under samples of symmetry angles, the maximum stitch density were those; under 20$^{\circ}$/-20$^{\circ}$, 30$^{\circ}$/-30$^{\circ}$, 60$^{\circ}$/-60$^{\circ}$: F1, F3-N1.5, F2-N2.0, under 45$^{\circ}$/-45$^{\circ}$: F1, F2-N2.0, F3-N1.5.

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