• Title/Summary/Keyword: non-normal distribution

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Dynamic Analysis of Tracked Vehicle by Buoy Characteristics (부이 특성에 따른 궤도 차량 동적 거동)

  • Kim, Hyung-Woo;Min, Cheon-Hong;Lee, Chang-Ho;Hong, Sup;Bae, Dae-Sung;Oh, Jae-Won
    • Ocean and Polar Research
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    • v.36 no.4
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    • pp.495-503
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    • 2014
  • This paper focuses on the dynamic responses of a tracked vehicle crawling on extremely cohesive soft soil, each side of which is composed of two parallel tracks. The tracked vehicle consisted of 2 bodies. One body is the tracked vehicle body, which is assumed to be a rigid body with 6 DOFs. The other body is the buoy body. The two bodies are connected by a revolute joint. In order to evaluate the travelling performance of a 7 DOFs vehicle, a dynamic analysis program for the tracked vehicle was developed using Newmark's method and the incremental-iterative method. The effects of road wheels on the track and soil are not taken into account. A terra-mechanics model of extremely cohesive soft soil is implemented in form of relationships: normal pressure to sinkage, shear resistance to shear displacement, and dynamic sinkage to shear displacement. Pressure-sinkage relationship and shear displacement-stress relationship should represent the non-linear characteristics of extremely soft soil. Especially, since the shear resistance of soft soil is very sensitive to shear displacement, spatial distribution of shear displacement occurring at the contact area of the tracks should be calculated precisely. The proposed program is developed in FORTRAN.

Effect of Horizontal Eye Movements on the Heart Rate Variability after Exposure to a Fear-Inducing Film Clip (공포 영화 장면 노출 후 수평적 안구 운동이 심박수 변이도에 미치는 영향)

  • Lee, Haewon;Yum, Myung-Kul;Kim, Seok Hyeon;Lee, Yun Jeong;Kim, Daeho
    • Korean Journal of Biological Psychiatry
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    • v.15 no.1
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    • pp.35-45
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    • 2008
  • Objectives : There has been a continued debate regarding the role of eye movements in Eye Movement Desensitization and Reprocessing(EMDR). This study examined the possible autonomic effect of horizontal eye movements after being exposed to fearful stimuli. Methods : Fifty two healthy adult women were randomly allocated to eye movement or eye fixed groups after watching a five minute fear-inducing film clip. ECG was recorded during the resting state, after watching the clip, and the treatment. A spectral power analysis of the heart rate variability was performed. As the variables violated the rule of normal distribution and the number in each group is small the non-parametric test was used. Results : Overall, we did not find the differences between the groups in both time and frequency domains. Some minor differences found were not consistent with results from previous studies. Conclusions : Effect of eye movement on autonomic nervous system during fear desensitization was not supported in this experiment. Further study with other psychophysiological measures is needed to understand the role of eye movements in treatment of traumatic memory.

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Effects of Citri Reticulatae Viride Pericarpium on the Apoptotic Cell Death in Breast Cancer Cells (청피(靑皮)가 유방암세포의 Apoptosis에 미치는 영향)

  • Kim, Ji-Eun;Park, Soo-Yeon;Choi, Chang-Won;Kim, Kyeong-Soo;Kim, Kyeong-Ok;Wei, Tung-Shuen;Yang, Seung-Joung
    • The Journal of Korean Obstetrics and Gynecology
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    • v.28 no.2
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    • pp.40-54
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    • 2015
  • Objectives : In the theory of Korean medicine, Citri Reticulatae Viride Pericarpium (CRVP) can soothe the liver to break qi stagnation, eliminate mass and relieve dyspepsia. This study was carried out to investigate the effects of CRVP on the apoptotic cell death in breast cancer cells. Methods : In the present experiment, the effects of CRVP on proliferation rates, type of cell death, cell cycle distribution, and intracellular oxidative stress were investigated using MDA-MB-231 cells in vitro. In addition, the effects on expression levels of caspase 3, caspase 9, Bax and Bcl-2 were also investigated. Results : Treatment with CRVP decreased proliferation rates in a dose dependent manner. ID50 (50% inhibitory dosage) was 175.4 μg/ml. In the CRVP treated group, cell volumes showed smaller than non-treated normal. In addition, CRVP increased percentage of apoptotic and sub G1 arrested cells respectively. 200 μg/ml of CRVP treatment increased intracellular ROS level significantly. Finaly the expression level of caspase 3 and Bax/Bcl-2 ratio were elevated by treatment with CRVP respectively. Conclusions : These results suggest that CRVP can trigger intrinsic apoptotic pathway in MDA-MB-231 cells.

A Positioning Scheme Using Sensing Range Control in Wireless Sensor Networks (무선 센서 네트워크 환경에서 센싱 반경 조절을 이용한 위치 측정 기법)

  • Park, Hyuk;Hwang, Dongkyo;Park, Junho;Seong, Dong-Ook;Yoo, Jaesoo
    • The Journal of the Korea Contents Association
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    • v.13 no.2
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    • pp.52-61
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    • 2013
  • In wireless sensor networks, the geographical positioning scheme is one of core technologies for sensor applications such as disaster monitoring and environment monitoring. For this reason, studies on range-free positioning schemes have been actively progressing. The density probability scheme based on central limit theorem and normal distribution was proposed to improve the location accuracy in non-uniform sensor network environments. The density probability scheme measures the final positions of unknown nodes by estimating distance through the sensor node communication. However, it has a problem that all of the neighboring nodes have the same 1-hop distance. In this paper, we propose an efficient sensor positioning scheme that overcomes this problem. The proposed scheme performs the second positioning step through the sensing range control after estimating the 1-hop distance of each node in order to minimize the estimation error. Our experimental results show that our proposed scheme improves the accuracy of sensor positioning by about 9% over the density probability scheme and by about 48% over the DV-HOP scheme.

Prevalence of High Risk Human Papillomavirus Infection with Different Cervical Cytological Features among Women Undergoing Health Examination at the National Cancer Institute, Thailand

  • Laowahutanont, Piyawat;Karalak, Anant;Wongsena, Metee;Loonprom, Komson;Pukcharoen, Phuttalak;Jamsri, Paphawin;Sangrajrang, Suleeporn
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.14
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    • pp.5879-5882
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    • 2014
  • High-risk (HR) human papillomavirus (HPV) testing is important in cervical cancer screening for triage colposcopy. The objective of the study was to evaluate the prevalence of HR HPV infection with different cervical cytological features among women undergoing health examination. A total of 2,897 women were retrospectively evaluated between May 2011 to December 2011. DNA was extracted from residual specimens collected during routine liquid-based cytology tests at the National Cancer Institute. Overall, HR HPV prevalence was 9.3% including 1.6% of HPV-16 and 0.4% of HPV-18. Of all 270 HPV positive samples, 211 (78.1% were HR-HPV non 16/18; 47 (17.4%) were HPV-16 and 12 (4.4%) were HPV-18. The prevalence of HPV infection was similar in all age groups, although a higher rate was observed in women age 31-40 years. Among women with normal cytology, HR HPV positive were found in 6.7%. In abnormal cytology, HR HPV were found 46.7% in atypical squamous cells (ASC), 54.8% in low-grade squamous intraepithelial lesions (LSIL) and 80.0% in high-grade squamous intraepithelial lesions (HSIL). HPV-16 was detected in 8.6%, 6.4% and 12.0% of ASC, LSIL and HSIL, respectively. The results of this study provide baseline information on the HPV type distribution, which may be useful for clinicians to decide who should be monitored or treated more aggressively.

Study on natural killer cell activity and its characteristics during hepatocarcinogenesis in rats (랫드의 간암 발생과정에서 분리한 자연살해세포의 활성측정 및 특성연구)

  • Jeong, Ja-young;Lee, Kuk-kyung;Kil, Jwang-sup;Lee, Yong-soon
    • Korean Journal of Veterinary Research
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    • v.39 no.1
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    • pp.169-176
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    • 1999
  • The purposes of this study were to set up the method of the natural killer(NK) cell activity assay using the flow cytometer and to examine the characteristics and distribution of the NK cell during rat hepatocarcinogenesis. Forty five male 6 week-old specific pathogen free(SPF) Sprague-Dawley rats were randomly divided into three groups. Group I was the non-treated control and given normal diet and water. Group II was treated with diethylnitrosamine(DEN, 200mg/kg, i.p.) and partial hepatectomy. Group III was treated with DEN, partial hepatectomy and 0.05% phenobarbital sodium in water from 3 to 16 weeks. All animals were examined the morphology of the large granular lymphocyte(LGL), the LGL percent of the total lymphocytes and the LGL conjugation rate with YAC-1 cell in peripheral blood, spleen and liver. Moreover, activity of the LGL isolated from peripheral blood lymphocytes was determined using the flow cytometer. As results, LGL were observed in the peripheral blood, spleen and liver. LGL were observed the relatively faintly staining basophilic cytoplasm with granules, and eccentric, often kidney-shaped nuclei in Giemsa stain. Its size was $11{\sim}13{\mu}m$. LGL percentage of the isolated lymphocytes in peripheral blood, spleen and liver were 1.8~2.3%, 1.3~1.4% and 0.87~0.99%, respectively. LGL conjugation rate with YAC-1 cell was shown to be peripheral blood(9.3~10.3 %) > spleen(7.7~8.7%) > liver(5.6~7.0%). The activity of the LGL isolated from peripheral blood lymphocytes in Group I, II and III was 33.7%, 30.5% and 35.4%, respectively. However, all values were not significantly between groups.

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A comparison on coefficient estimation methods in single index models (단일지표모형에서 계수 추정방법의 비교)

  • Choi, Young-Woong;Kang, Kee-Hoon
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.6
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    • pp.1171-1180
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    • 2010
  • It is well known that the asymptotic convergence rates of nonparametric regression estimator gets worse as the dimension of covariates gets larger. One possible way to overcome this problem is reducing the dimension of covariates by using single index models. Two coefficient estimation methods in single index models are introduced. One is semiparametric least square estimation method, which tries to find approximate solution by using iterative computation. The other one is weighted average derivative estimation method, which is non-iterative method. Both of these methods offer the parametric convergence rate to normal distribution. However, practical comparison of these two methods has not been done yet. In this article, we compare these methods by examining the variances of estimators in various models.

Datawise Discriminant Analysis For Feature Extraction (자료별 분류분석(DDA)에 의한 특징추출)

  • Park, Myoung-Soo;Choi, Jin-Young
    • Journal of the Korean Institute of Intelligent Systems
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    • v.19 no.1
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    • pp.90-95
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    • 2009
  • This paper presents a new feature extraction algorithm which can deal with the problems of linear discriminant analysis, widely used for linear dimensionality reduction. The scatter matrices included in linear discriminant analysis are defined by the distances between each datum and its class mean, and those between class means and mean of whole data. Use of these scatter matrices can cause computational problems and the limitation on the number of features. In addition, these definition assumes that the data distribution is unimodal and normal, for the cases not satisfying this assumption the appropriate features are not achieved. In this paper we define a new scatter matrix which is based on the differently weighted distances between individual data, and presents a feature extraction algorithm using this scatter matrix. With this new method. the mentioned problems of linear discriminant analysis can be avoided, and the features appropriate for discriminating data can be achieved. The performance of this new method is shown by experiments.

Analysis of Nursing Research Trend Associated with Breast Cancer in Korea (유방암 관련 국내 간호연구 동향)

  • Park, Young-Mi;Lee, Hyang-Yeon
    • Journal of East-West Nursing Research
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    • v.9 no.1
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    • pp.91-103
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    • 2004
  • Purpose: This study was attempted to see the trends in breast cancer researches in Korea. Method: We collected a total of 94 articles associated with breast cancer and published in Korea from 1976 to August 2004 and analyzed the characteristics of those articles, the journals which published those articles in each year, the research designs, subjects, intervention effects in experimental studies, the subjects and concept distribution in comparative researches and themes of the articles. Result: 1. Articles published and associated with breast cancer have increased since 1990 and picked after 2000. 2. Most research designs are survey and correlation studies which are non-experimental research(70.2%) and next are experimental and qualitative researches. 3. In a total 17 articles which are experimental researches, intervention studies which use exercise programs are most(5 articles) and the next are education program, supportive nursing intervention, guided imagery, massage and rehabilitation programs. 4. In correlational researches, concepts such like social-psychological adaptation, partner support, health promotion behavior and family support are treated frequently. 5. Subjects in most comparative studies are patients with breast cancer and normal women. 6. Most nursing research themes are psycho/spiritual problems, 16 articles(17.0%). Conclusion: These results show that the researches related with breast cancer have actively increased and body functions and psycho-social variables have been improved through nursing intervention. Therefore, it seems that more systematic interdisciplinary studies and systematic complement are necessary for future breast cancer nursing researches.

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Operational modal analysis of Canton Tower by a fast frequency domain Bayesian method

  • Zhang, Feng-Liang;Ni, Yi-Qing;Ni, Yan-Chun;Wang, You-Wu
    • Smart Structures and Systems
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    • v.17 no.2
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    • pp.209-230
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    • 2016
  • The Canton Tower is a high-rise slender structure with a height of 610 m. A structural health monitoring system has been instrumented on the structure, by which data is continuously monitored. This paper presents an investigation on the identified modal properties of the Canton Tower using ambient vibration data collected during a whole day (24 hours). A recently developed Fast Bayesian FFT method is utilized for operational modal analysis on the basis of the measured acceleration data. The approach views modal identification as an inference problem where probability is used as a measure for the relative plausibility of outcomes given a model of the structure and measured data. Focusing on the first several modes, the modal properties of this supertall slender structure are identified on non-overlapping time windows during the whole day under normal wind speed. With the identified modal parameters and the associated posterior uncertainty, the distribution of the modal parameters in the future is predicted and assessed. By defining the modal root-mean-square value in terms of the power spectral density of modal force identified, the identified natural frequencies and damping ratios versus the vibration amplitude are investigated with the associated posterior uncertainty considered. Meanwhile, the correlations between modal parameters and temperature, modal parameters and wind speed are studied. For comparison purpose, the frequency domain decomposition (FDD) method is also utilized to identify the modal parameters. The identified results obtained by the Bayesian method, the FDD method and a finite element model are compared and discussed.