• Title/Summary/Keyword: Heterogeneity measure

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Species Diversity and Niche Breadth of the Herb Layer Communities in Young Open Natural Pinus densiflora Stands (자연생유령 소나무림내 초본층의 종다양도와 생태적지위량에 대하여)

  • 오규칠
    • Journal of Plant Biology
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    • v.17 no.4
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    • pp.18-22
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    • 1974
  • Counts of herb stems were made with each systematic grid sized 10cm by 1300cm within six apparently homogeneous herb layers under the open young Japanese red pine, Pinus densiflora, stands. The stands had often been subjected to strong human interferences such as burning, cutting, grazing, and denuding since human settlement until the conservation scheme practiced in these stands for last decade. In addition, amounts of loss of ignition and field capacity were determined to detect soil heterogeneity among and within the stands. The values of information measure of diversity(H), and Hurlbert's probability of interspecfic encounter(Δ), obtained here do not show any consistent correlation. The amount of interspecific competetion(Δ1), the ratio of interspecific to intraspecific competetion(Δ4), Levin's niche breadth(Sh), and species evenness(V), increase, while the amount of intraspecific competetion decrease, as the soil factors become favorable. One stand examined does not follow the above trends, which is more young and shows strong within site heterogeneity of the soil factors. The stand includes pioneer species which is not detectable without detailed observation. It is argued that in stable or favorable environment more intense interspecific competetion and less intraspecific competetion might occur, but this situation does not necessarily always bring smaller niche breadth. In this connection, the results support Hurlbert's contention that the two components of diversity should be analyzed separately.

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The Impact of Manual Therapy on Pain Catastrophizing in Chronic Pain Conditions: A Systematic Review and Meta-analysis

  • Hyunjoong Kim;Seungwon Lee
    • Physical Therapy Rehabilitation Science
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    • v.12 no.2
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    • pp.177-184
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    • 2023
  • Objective: Manual therapy is a commonly utilized approach in managing chronic pain, but its specific impact on pain catastrophizing remains uncertain. The objective of this systematic review and meta-analysis was to examine the effects of manual therapy on pain catastrophizing in individuals with chronic pain. Design: A systematic review and meta-analysis Methods: A comprehensive search was conducted in electronic databases to identify relevant studies published from 2014 onwards. Studies that evaluated the impact of manual therapy on pain catastrophizing in individuals with chronic pain were incorporated. The risk of bias in the selected studies was evaluated using the Cochrane tool for risk of bias in qualitative analysis. For the quantitative analysis, RevMan 5.4 software was utilized, employing a random-effects model as the analysis model. The effect measure used in the analysis was the standardized mean difference (SMD). Results: In total, 26 studies were collected, and following the screening process, three of them were incorporated into the final analysis. The included studies involved a total of 153 patients with chronic pain. The interventions comprised various manual therapy techniques targeting different areas of the body. Pain catastrophizing and pain intensity were the primary outcomes of interest. The meta-analysis revealed a significant reduction in pain catastrophizing scores following manual therapy intervention compared to control conditions (SMD = -0.91, 95% CI: -1.25 to -0.58). However, heterogeneity between the studies was observed. Conclusions: Despite the limited quantity and heterogeneity of studies, it has been demonstrated that manual therapy intervention is effective in reducing pain catastrophizing in individuals with chronic pain.

Analyzing the Casual Relationship among Employee Satisfaction, Productivity and Customer Satisfaction Considering Employee' Work Ability (종업원의 업무능력을 고려한 종업원 만족도, 생산성 및 고객만족 간 인과관계 분석)

  • Kim, Chan-Gyu;Park, Young-Joon;Kim, Tae-Ho
    • IE interfaces
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    • v.16 no.spc
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    • pp.116-122
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    • 2003
  • We analyze how much employees' work abilities and overall satisfaction on the job or corporate influence on the productivity and customer satisfaction in the service industry, which is characterized by simultaneity, heterogeneity, intangibility and etc. Employees always encounter customers in process of the service. So, the employees' attitudes and behaviors have direct influences on the service quality or satisfaction which customers perceive. Also, employees' satisfaction or work abilities can lead to increase or decrease the productivity. To grasp and demonstrate the cause and effect relationship, we firstly measure the degrees of employee satisfaction organized by 11 factors through survey, and also measure employees' overall satisfaction, organizational commitment and productivity. Secondly, we define service value as the employee's objective measure index and collect it with the data related to customer satisfaction. Based on the collected data, thirdly we define how the relationship among the employee satisfaction, the productivity, the service value and the customer satisfaction are affected by the employees' work abilities and overall satisfaction with SEM(Structural Equation Model). And finally, we classify employees according to their abilities and the degrees of satisfaction respectively and suggest important strategies to manage them effectively.

Modeling the Effect of Consideration Set-Based Reference Price: Empirical Bayes & Latent Class Approach (고려상품군을 반영한 준거가격효과의 모형화: Empirical Bayes & Latent Class Approach)

  • Chang, Kwangpil
    • Asia Marketing Journal
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    • v.8 no.1
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    • pp.1-17
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    • 2006
  • A couple of previous studies have warned against the use of homogeneous choice models in assessing the effect of reference price since unaccounted for response heterogeneity may result in spurious reference price effects(Chang, Siddarth and Weinberg 1999; Bell and Lattin 2000). According to Meyer and Kahn(1991), not accounting for consideration set heterogeneity may also bias the effect parameters in the choice model. Therefore, failure to account for these two sources of bias, in fact, have cast doubt on the empirical support for reference price effects in general. In view of aforementioned potential sources of bias, the author investigates the robustness of loss aversion effect in the reference-dependent model after accounting for heterogeneity in response as well as consideration set. The proposed model defines individual household's consideration set based on the posterior distribution of preference obtained from the Empirical Bayes approach. In addition, the same posterior distribution is used to form household-specific reference prices. Response heterogeneity correction is carried out via the Latent Class approach. The proposed model outperforms the Reference-Dependent model that includes the reference price measure most often employed in the previous studies. This implies that as a way of simplifying decision task, consumers restrict their consideration set to a subset of available brands not only in making a brand choice but also in forming reference prices.

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Improved Rayleigh Wave Velocity Measurement Technique for Early-age Concrete Monitoring (초기 재령 콘크리트의 모니터링을 위한 개선된 레일리파 속도 측정 기법)

  • Shin Sung-Woo;Yun Chung-Bang;Popovics John S.;Song Won-Joon
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 2006.04a
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    • pp.97-103
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    • 2006
  • A modified one-sided measurement technique is proposed for Rayleigh wave (R-wave) velocity measurement in concrete. The scattering from heterogeneity may affect the waveforms of R-waves in concrete, which may make the R-waves dispersive. Conventional one-sided techniques do not consider the scattering dispersion of R-waves in concrete. In this study, the maximum energy arrival concept is adopted to determine the wave velocity by employing its continuous wavelet transform. Experimental study was performed to show the effectiveness of the proposed method. The present method is applied to monitor the strength development of early-age concrete. A series of experiments were performed on early-age concrete specimens with various curing conditions. Results reveal that the proposed method can be effectively used to measure the R-wave velocity in concrete structures and to monitor the strength development of early-age concrete.

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Design and Implementation of Flexible Sensor to Measure Mechanical Stiffness of Soft Particles (Soft Particle의 강성 측정을 위한 단순한 구조의 유연 물질 센서의 개발)

  • Ihn, Yong Seok;Yang, Minho;Koo, Ja Choon
    • The Journal of Korea Robotics Society
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    • v.11 no.3
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    • pp.133-139
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    • 2016
  • Increasing interest of human health, building bio-database (Bio DB) has been become a hot issue in life science. Consequently, Single Cell Analysis (SCA) which can explain biodiversity of lives has been a significant factor for building Bio DB. In numerous studies from these analyses, they have been showed that mechanical properties of cells can serve explanation of biological heterogeneity and criterion of disease states. Therefore, measuring mechanical properties of cells have great potential to be used in bio-medical applications. However, traditionally, many researchers have undergone difficult and time consuming work because handling small sized cells usually requires high-skilled technique. Thus, this paper shows robotized stiffness measurement technique using fixed ended beam sensor, precision motorized stage and substrate which have wall structure.

Comparative Study on Mathematics Text-book of Secondary Schools in South and North Korea -From the Viewpoint of the Region of Algebra, Statistics, Analysis and Geometry- (남.북한 중등학교 수학 교과서의 영역별 내용 비교 분석 -대수, 통계, 해석, 기하 영역을 중심으로-)

  • Kim, Sam-Tae;Lee, Sik
    • The Mathematical Education
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    • v.38 no.1
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    • pp.1-14
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    • 1999
  • It has already been fifty years since the Korean peninsula was divided into two nations, South and North Korea. Owing to forming different political and social structures with each other, we can conjecture that there are much heterogeneity in education. On the assumption that education plays important role in coming to an accommodation and in restoring homogeneity of the Korean race after unification, we consider the investigation of the contents of mathematics text-book of secondary schools as a meaningful research to make provision against unification. In this paper, we shall investigate the learning contents, and the teaming substances and sequences in mathematics of secondary schools between South and North Korea by falling into four regions; algebra and statistics, analysis and geometry. By grasping the special features of terms, teaming subject matters and learning substances, and clarifying their distinctions, we shall present some reforms measure of distinctions.

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PathTalk: Interpretation of Microarray Gene-Expression Clusters in Association with Biological Pathways

  • Chung, Tae-Su;Chung, Hee-Joon;Kim, Ju-Han
    • Genomics & Informatics
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    • v.5 no.3
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    • pp.124-128
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    • 2007
  • Microarray technology enables us to measure the expression of tens of thousands of genes simultaneously under various experimental conditions. Clustering analysis is one of the most successful methods for analyzing microarray data using the assumption that co-expressed genes may be co-regulated. It is important to extract meaningful clusters from a long unordered list of clusters and to evaluate the functional homogeneity and heterogeneity of clusters. Many quality measures for clustering results have been suggested in different conditions. In the present study, we consider biological pathways as a collection of biological knowledge and used them as a reference for measuring the quality of clustering results and functional homogeneities. PathTalk visualizes and evaluates functional relationships between gene clusters and biological pathways.

Association between pesticide and polychlorinated biphenyl exposure during pregnancy and autism spectrum disorder among children: a meta-analysis

  • Mehri, Fereshteh;Bashirian, Saeid;Khazaei, Salman;Jenabi, Ensiyeh
    • Clinical and Experimental Pediatrics
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    • v.64 no.6
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    • pp.286-292
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    • 2021
  • Background: The effect of exposure to environmental factors on autism spectrum disorders (ASD), especially during pregnancy, is unclear. Purpose: This meta-analysis investigated the association between exposure to pesticides and polychlorinated biphenyls (PCBs) during pregnancy and ASD risk among children. Methods: We searched Scopus, PubMed, Web of Science, and ProQuest for articles published through September 2019. Random-effects models were used to examine the association among studies using pooled odds ratios (ORs) and their 95% confidence intervals (CI). I2 tests were used to measure interstudy heterogeneity. Results: The pooled OR indicated a significant association between PCB and pesticide exposure during pregnancy and ASD risk among children (OR, 1.80; 95% CI, 1.26-2.34; and OR, 1.20; 95% CI, 1.02-1.39), respectively. Conclusion: Findings of the present study indicate that exposure to pesticides and PCBs during pregnancy may affect the risk of ASD among children.

A Web Caching for Improvement of Processing Performance on a Multimedia Object (멀티미디어 객체 처리 성능 향상을 위한 웹 캐싱)

  • Na Yun Ji;Ko Il Seok
    • The KIPS Transactions:PartA
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    • v.11A no.7 s.91
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    • pp.469-474
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    • 2004
  • As traffic on the web increases, users are faced with increasing delays. A key performance measure for the web is the speed with which object is served to users. Web caching is the one of the key method that improve performance of Web base system. Also, many studies for efficient management of storing scope on cache are performed actively. An important issue in web caching is how to improve a efficiency of a caching system. For this, efficient web cache management is required. A solution for this is to set up the caching strategy that consider a heterogeneity of Web object. In this paper, We propose a new web caching technique for a performance improvement of a multimedia object process. The proposed method is based on a heterogeneity of Web object, and it increases performance of a caching system by increasing the caching efficiency of a multimedia object. In the experiment, We verified performance improvement of proposed web caching system through performance analysis of a proposed system.