• Title/Summary/Keyword: divided differences

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A Study on the Evaluation of Bibliographic Instruction with Reference to the Effectiveness Differences among College Student Groups (도서관 이용교육 효과의 집단별 차이에 관한 연구)

  • Chang Hye Rhan
    • Journal of the Korean Society for Library and Information Science
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    • v.17
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    • pp.261-273
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    • 1989
  • The study attempted to determine if the effectiveness of bibliographic 'instruction would be different among student groups, divided by grade levels, major areas of study, and the level of library skills posessed before the instruction. The focal point of the investigation was the degree of improvement demonstrated by the changes in mean score of each group after taking bibliographic instruction. Sangmyong Women's University students who have taken the bibliographic instruction course for credit were the subjects of the study. Students' library skills were measured prior to the bibliographic instruction and post-test was followed. And the measured was based on the 'Library skills Test' developed by the Illinois Association of College and Research Libraries. Three hypotheses in the study were tested statistically by ANOVA. The followings are the results of the analysis: (1) There were no significant differences in bibliographic instruction effectiveness among student groups divided by grade levels; (2) There were significant differences (p<.01) in bibliographic instruction effectiveness among student groups divided by major areas of study. Bibliographic instruction was more effective for humanities or social sciences majors than for performing arts or physical education majors; (3) There were significant differences (p<.001) in bibliographic instruction effectiveness among student groups divided by the initial library skills. Obviously, bibliographic instruction was more effective for the students in bottom quartile than those in top quartile or middle quartiles. Finally, limitations of the study, recommendations based on the results and area for future research are briefly examined.

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ON A QUADRATICALLY CONVERGENT ITERATIVE METHOD USING DIVIDED DIFFERENCES OF ORDER ONE

  • Argyros, Ioannis K.
    • The Pure and Applied Mathematics
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    • v.14 no.3
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    • pp.203-221
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    • 2007
  • We introduce a new two-point iterative method to approximate solutions of nonlinear operator equations. The method uses only divided differences of order one, and two previous iterates. However in contrast to the Secant method which is of order 1.618..., our method is of order two. A local and a semilocal convergence analysis is provided based on the majorizing principle. Finally the monotone convergence of the method is explored on partially ordered topological spaces. Numerical examples are also provided where our results compare favorably to earlier ones [1], [4], [5], [19].

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A Study on the Body Characteristics of Korean Obese Women (Part I)

  • Yi, Kyong-Hwa
    • Journal of the Korean Society of Clothing and Textiles
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    • v.34 no.6
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    • pp.937-954
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    • 2010
  • This study analyzes the body characteristics of Korean obese women using 2004 Size Korea data. For selecting the obesity sample, 7 obesity judgment indices were chosen from previous clothing-related studies. A total of 636 females defined as "obese" by 5 out of 7 indices were selected as subjects for this study. 54 body measurements and obesity judgment indices were used. First, the subjects had a BMI 27.11, R$\ddot{o}$hrer index 1.76, Vervaeck index 104.77, Relative weight 133.00, and WHR 0.90. In the case of the distribution by age groups, the twenties were 6.4% of the entire subjects, the thirties were 18.2%, the forties were 16.4%, the fifties were 37.4%, and the sixties were 21.5%. The result of the ANOVAs (divided into 5 age groups) showed significant differences in 41 measurement items except for bust circumference, waist length front, and all of obesity judgment indices. Second, according to the ANOVAs among stature groups divided by 5cm pitches there are significant differences in all measurements except for bust circumference. The results of the ANOVAs among bust circumference groups divided by 5cm pitches show that significant differences were observed in all measurements except four measurement items (including body rise). According to the ANOVAs among the waist circumference groups divided by 5cm pitches, there are no significant differences in all height measurements and shoulder length, waist to hip length, and crotch length. It is confirmed that stature and bust circumference have a deep relationship with measurements other than waist circumference. Third, as the factor analysis were conducted using 39 measurement items to extract the body characteristics of obese women Factor 1 is "circumference measurements & obesity judgment indices," Factor 2 is "heights & arm-related lengths," and Factor 3 is "size and ratio of waist circumference & hip circumference." Factor 4 was "lengths in upper body," Factor 5 was "back width in upper body," Factor 6 was "side neck point to bust & bust circumference," Factor 7 was "length in lower body & arm circumferences," and Factor 8 was "neck base circumference & front widths in upper body." These 8 factors explained 76.54% of the total variance.

LOCAL CONVERGENCE OF THE SECANT METHOD UPPER $H{\ddot{O}}LDER$ CONTINUOUS DIVIDED DIFFERENCES

  • Argyros, Ioannis K.
    • East Asian mathematical journal
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    • v.24 no.1
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    • pp.21-25
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    • 2008
  • The semilocal convergence of the secant method under $H{\ddot{o}}lder$ continuous divided differences in a Banach space setting for solving nonlinear equations has been examined by us in [3]. The local convergence was recently examined in [4]. Motivated by optimization considerations and using the same hypotheses but more precise estimates than in [4] we provide a local convergence analysis with the following advantages: larger radius of convergence and finer error estimates on the distances involved. The results can be used for projection methods, to develop the cheapest possible mesh refinement strategies and to solve equations involving autonomous differential equations [1], [4], [7], [8].

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A CLASS OF COMPLETELY MONOTONIC FUNCTIONS INVOLVING DIVIDED DIFFERENCES OF THE PSI AND TRI-GAMMA FUNCTIONS AND SOME APPLICATIONS

  • Guo, Bai-Ni;Qi, Feng
    • Journal of the Korean Mathematical Society
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    • v.48 no.3
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    • pp.655-667
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    • 2011
  • A class of functions involving divided differences of the psi and tri-gamma functions and originating from Kershaw's double inequality are proved to be completely monotonic. As applications of these results, the monotonicity and convexity of a function involving the ratio of two gamma functions and originating from the establishment of the best upper and lower bounds in Kershaw's double inequality are derived, two sharp double inequalities involving ratios of double factorials are recovered, the probability integral or error function is estimated, a double inequality for ratio of the volumes of the unit balls in $\mathbb{R}^{n-1}$ and $\mathbb{R}^n$ respectively is deduced, and a symmetrical upper and lower bounds for the gamma function in terms of the psi function is generalized.

A Pilot Selection Method Using Divided Attention Test (주의 분배력 분석을 통한 조종사 선발 방법에 관한 연구)

  • Lee Dal-Ho
    • Journal of the military operations research society of Korea
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    • v.11 no.1
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    • pp.33-46
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    • 1985
  • This study develops a scientific method in pilot selection by analysing a divided attention performance between the successful pilots and the failures in a flight training course. To measure the divided attention performance, Dual Task Method is used in which the primary task is a tracking task while the secondary tasks are, 1. short-term memory task 2. choice reaction task 3. judgement task. Result shows that the performance of the pilots is significantly better (p < 0.1) than that of the failures in divided attention performance. In addition, the differences in the divided attention performance between the two groups are increased in proportion to the difficulty of the task and especially in the short term memory, the increment is most dramatic.

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Analysis of Clinical Outcome and Prognosis for Lisfranc Joint Fracture and Dislocation according to the Injury Mechanism and Treatment Method (리스프랑 관절 골절 및 탈구의 수상 기전과 치료 방법에 따른 임상적 결과와 예후 분석)

  • Park, Hyun-Woo;Yi, Hyung Suk
    • Journal of Korean Foot and Ankle Society
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    • v.18 no.3
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    • pp.124-128
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    • 2014
  • Purpose: The purpose of this study was to assess the treatment outcomes and prognosis of Lisfranc joint fracture and dislocation according to the mechanism of injury and treatment method. Materials and Methods: Twenty six patients with Lisfranc fracture-dislocation who had been treated surgically were included in this retrospective study. The patients were divided into two groups according to mechanism of injury: direct crushing injury (16 patients) and indirect rotational or compressive injury (10 patients). The patients were also divided into three groups according to the surgical methods. The parameters used were radiographic evaluation, patients' subjective satisfaction levels, length of hospital stay, and the American Orthopaedic Foot and Ankle Society (AOFAS) midfoot score. Statistical analysis was performed. Results: The mean postoperative AOFAS midfoot score was 78.7. The mean length of stay was 39.6 days. Statistically significant differences in subjective satisfaction, AOFAS midfoot score, and length of hospital stay were observed between the two groups (p<0.05). However, no significance differences were observed between the three groups who were divided according to the different surgical methods (p>0.05). Conclusion: Mechanism of trauma and the severity of soft-tissue injury were significant prognostic factors affecting the surgical outcomes of Lisfranc joint fracture and dislocation.

The Effects of Fashion Innovativeness and Purchase Situation Factors on Fashion Adoption among Adult Women (성인여성의 유행혁신성과 구매상황 요인이 유행채택행동에 미치는 영향)

  • Jun, Dae-Geun
    • Journal of the Korean Home Economics Association
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    • v.46 no.8
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    • pp.109-120
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    • 2008
  • This study aimed to identify the effects of adult women's fashion innovativeness and purchase situation factors on fashion adoption. To explain women's fashion adoption at the point of clothing purchases, fashion innovativeness and 3 dimensions of purchase situation were adopted as explanatory variables. Total usable questionnaires were obtained from 801 women aged between 20 and 39. Factor analysis on purchase situation resulted in 3 dimensional structures of purchase situation: Store atmosphere, Store policy and Pre-purchase condition. Women groups divided by fashion innovativeness level showed meaningful differences in their purchase situation level and fashion adoption level. Women groups divided by 3 dimensions of purchase situation also showed significant differences in fashion innovativeness level and fashion adoption level. Fashion innovativeness, Store atmosphere and Pre-purchase condition except Store policy positively affected fashion adoption.

24 Hours Blood Pressure Variation and Related Risk factors (24시간 혈압 변동과 관련 위험 요인)

  • Choi In-Joo;Kim Young-Mi;Lee Hae-Jung
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.12 no.3
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    • pp.307-316
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    • 2005
  • Purpose: The purpose of this study was to identify 24 hours blood pressure variations among adults over 40 years of age. Method: The participants(50 adults) were recruited from P hospital and B company. The participants were divided into normotensive and hypertensive tendency groups and then sub-divided into non-dipper, dipper, and extreme dipper. The data were collected from April, 2003 to September, 2004 and analyzed using SPSS for Window program. Results: 1) There were significant differences in cardiovascular risk factor, systolic and diastolic blood pressures, and LDH, diet between the normotensive and hypertensive tendency groups. 2) Dippers in both groups showed a marked decrease in blood pressure during the night, but non-dippers in both groups didn't show a marked nocturnal decrease in blood pressure. 3) There were significant differences in heart rate, WHR, BMI, LDH, triglyceride, glucose, affective-oriented coping strategies between dippers and non-dippers. 4) There were significant differences in heart rate, WHR, BMI, LDH, triglyceride, affective-oriented coping strategies between dipper and non-dipper within hypertensive tendency group. Conclusion: Further studies are needed to provide effective intervention in hypertension when applying 24 hour blood pressure monitoring.

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A Pilot Selection Method using Divided Attention Test (주의력 배분능력 분석을 통한 조종사 선발방법에 관한 연구)

  • Lee, Dal-Ho;Lee, Myeon-U
    • Journal of Korean Institute of Industrial Engineers
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    • v.10 no.2
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    • pp.3-16
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    • 1984
  • This study develops a scientific method in pilot selection by analysing a divided attention performance between the successful pilots and the failures in a flight training course. To measure the divided attention performance, Dual Task Method is used in which the primary task is a tracking task while the secondary tasks are, 1. short term memory task, 2. choice reaction task and 3. judgement task. Result shows that the performance of the pilots is significantly better (P < 0.1) than that of the failures in dual performance. In addition, the differences in the divided attention performance between the two groups are increased in proportion to the difficulty of the task and especially in the Short Term Memory, the increment is most dramatic.

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