• Title/Summary/Keyword: Bias correlation

Search Result 342, Processing Time 0.027 seconds

Do Previous Promotion Awards Affect Current Decisions? Investigation of Intertemporal Correlations of Personnel Decisions

  • Kim, Jonghwan
    • Asia-Pacific Journal of Business
    • /
    • v.11 no.4
    • /
    • pp.1-19
    • /
    • 2020
  • Purpose - This study analyzes the intertemporal patterns in personnel decisions made between a supervisor and a subordinate to understand potential supervisor bias in the decisions. A correlation between the current and the most recent personnel decisions made for a subordinate by a current supervisor captures certain relationship-embedded and time-invariant factors in effect. The characteristics speak to the nature of a supervisor bias arising from a relationship, or favoritism. Design/methodology/approach - This study manually collects the executive profile data from annual reports of key Samsung Group affiliates and compile a longitudinal sample of 3,675 executive-years. It mainly explores the logistic regression analysis. Findings - The study finds that a supervisor' previous promotion award to a subordinate does not improve but decreases the likelihood of promotions in ensuing years, suggesting the containment of favoritism; and that the time since the last promotion award to a subordinate by the current supervisor increases the likelihood of both promotions and dismissals of the subordinate. Research implications or Originality - The findings are generally consistent with the theory suggesting that incentive schemes that align interests between an individual and an organization will contain the form of a supervisor bias.

Bias Correction of Satellite-Based Precipitation Using Convolutional Neural Network

  • Le, Xuan-Hien;Lee, Gi Ha
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2020.06a
    • /
    • pp.120-120
    • /
    • 2020
  • Spatial precipitation data is one of the essential components in modeling hydrological problems. The estimation of these data has achieved significant achievements own to the recent advances in remote sensing technology. However, there are still gaps between the satellite-derived rainfall data and observed data due to the significant dependence of rainfall on spatial and temporal characteristics. An effective approach based on the Convolutional Neural Network (CNN) model to correct the satellite-derived rainfall data is proposed in this study. The Mekong River basin, one of the largest river system in the world, was selected as a case study. The two gridded precipitation data sets with a spatial resolution of 0.25 degrees used in the CNN model are APHRODITE (Asian Precipitation - Highly-Resolved Observational Data Integration Towards Evaluation) and PERSIANN-CDR (Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks). In particular, PERSIANN-CDR data is exploited as satellite-based precipitation data and APHRODITE data is considered as observed rainfall data. In addition to developing a CNN model to correct the satellite-based rain data, another statistical method based on standard deviations for precipitation bias correction was also mentioned in this study. Estimated results indicate that the CNN model illustrates better performance both in spatial and temporal correlation when compared to the standard deviation method. The finding of this study indicated that the CNN model could produce reliable estimates for the gridded precipitation bias correction problem.

  • PDF

Estimation of BDI Volatility: Leverage GARCH Models (BDI의 변동성 추정: 레버리지 GARCH 모형을 중심으로)

  • Mo, Soo-Won;Lee, Kwang-Bae
    • Journal of Korea Port Economic Association
    • /
    • v.30 no.3
    • /
    • pp.1-14
    • /
    • 2014
  • This paper aims at measuring how new information is incorporated into volatility estimates. Various GARCH models are compared and estimated with daily BDI(Baltic Dry Index) data. While most researchers agree that volatility is predictable, they differ on how this volatility predictability should be modelled. This study, hence, introduces the asymmetric or leverage volatility models, in which good news and bad news have different predictability for future. We provide the systematic comparison of volatility models focusing on the asymmetric effect of news on volatility. Specifically, three diagnostic tests are provided: the sign bias test, the negative size bias test, and the positive size bias test. From the Ljung-Box test statistic for twelfth-order serial correlation for the level we do not find any significant serial correlation in the unpredictable BDI. The coefficients of skewness and kurtosis both indicate that the unpredictable BDI has a distribution which is skewed to the left and significantly flat tailed. Furthermore, the Ljung-Box test statistic for twelfth-order serial correlations in the squares strongly suggests the presence of time-varying volatility. The sign bias test, the negative size bias test, and the positive size bias test strongly indicate that large positive(negative) BDI shocks cause more volatility than small ones. This paper, also, shows that three leverage models have problems in capturing the correct impact of news on volatility and that negative shocks do not cause higher volatility than positive shocks. Specifically, the GARCH model successfully reveals the shape of the news impact curve and is a useful approach to modeling conditional heteroscedasticity of daily BDI.

A Study on Statistical Parameters for the Evaluation of Regional Air Quality Modeling Results - Focused on Fine Dust Modeling - (지역규모 대기질 모델 결과 평가를 위한 통계 검증지표 활용 - 미세먼지 모델링을 중심으로 -)

  • Kim, Cheol-Hee;Lee, Sang-Hyun;Jang, Min;Chun, Sungnam;Kang, Suji;Ko, Kwang-Kun;Lee, Jong-Jae;Lee, Hyo-Jung
    • Journal of Environmental Impact Assessment
    • /
    • v.29 no.4
    • /
    • pp.272-285
    • /
    • 2020
  • We investigated statistical evaluation parameters for 3D meteorological and air quality models and selected several quantitative indicator references, and summarized the reference values of the statistical parameters for domestic air quality modeling researcher. The finally selected 9 statistical parameters are MB (Mean Bias), ME (Mean Error), MNB (Mean Normalized Bias Error), MNE (Mean Absolute Gross Error), RMSE (Root Mean Square Error), IOA (Index of Agreement), R (Correlation Coefficient), FE (Fractional Error), FB (Fractional Bias), and the associated reference values are summarized. The results showed that MB and ME have been widely used in evaluating the meteorological model output, and NMB and NME are most frequently used for air quality model results. In addition, discussed are the presentation diagrams such as Soccer Plot, Taylor diagram, and Q-Q (Quantile-Quantile) diagram. The current results from our study is expected to be effectively used as the statistical evaluation parameters suitable for situation in Korea considering various characteristics such as including the mountainous surface areas.

Advanced Region Slopes Method to Reduce Code Tracking Bias in Future Global Navigation Satellite Systems (부호동기 추적편이 보상을 위한 이른영역기울기 기법)

  • Yoo, Seung-Soo;Lee, Young-Yoon;Kim, Yeong-Moon;Kim, Sun-Yong
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.34 no.10C
    • /
    • pp.1016-1023
    • /
    • 2009
  • In this paper, a tracking bias compensation method is proposed for future global navigation satellite systems (GNSSs). It is observed that the correlation function of a GNSS signal has many peaks and remains almost unchanged in the advanced offset region as a result of the multipath signals arriving at the receiver later than a line-of-sight signal. Based on these observations, we use the slopes in the advanced offset region to compensate for the code tracking bias, and obtain the maximum code tracking bias, which is essential to implement the proposed scheme, in static multipath environments. Finally, it is demonstrated that the proposed compensation method is very effective for the GNSS signal tracking in terms of the code tracking biases and their running averages.

Influence of Bias and Multicultural Attitude on Multicultural Efficacy in Elementary Students (초등학생의 편견과 다문화적태도가 다문화효능감에 미치는 영향)

  • Kim, Young-Tae
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.12 no.12
    • /
    • pp.5639-5647
    • /
    • 2011
  • The purpose of this study was to analyze the influence of bias and the multicultural attitude of elementary schoolchildren on the multicultural efficacy and to seek for the right direction of multicultural education in elementary school. To attain this purpose, this study asked 416 elementary schoolchildren to questions in Jeonbuk Province. The results are as follows. First, there is a significant difference on bias, multicultural attitude, and efficacy to gender and grade. Second, there is a meaningful correlation among bias, multicultural attitude, and multicultural efficacy. Third, the elementary schoolchildren's bias has a significant influence on the multicultural attitude and efficacy. Fourth, the elementary schoolchildren's multicultural attitude exercises a meaningful effect on the multicultural efficacy. According to this survey, a variety of multicultural programs for the elementary schoolchildren are needed to develop and apply in substance at the level of their eyes. In addition to that, a diversity of studies are needed constantly for making the elementary schoolchildren get some positive understanding on various cultures.

A Study on the Dual Mediating Effects of Individual Optimistic Bias and Information Security Intent in the Relationship between Information Security Attitude and Information Security Behavior of Social Welfare College Students (사회복지 전공대학생의 정보보안 태도와 정보보안 행위와의 관계에서 개인의 낙관적 편견과 정보보안 의도의 이중 매개효과)

  • Yun, Il-Hyun
    • Journal of Industrial Convergence
    • /
    • v.19 no.6
    • /
    • pp.145-153
    • /
    • 2021
  • This study empirically verified whether there is a dual mediating effect of individual optimistic bias and information security intention in the relationship between information security attitude and information security behavior of social welfare college students. The subjects were 295 college students majoring in social welfare. Spss Process macro was used for analysis. As a result. first there was a significant positive correlation between the variables. Second in the relationship between information security attitude and information security behavior, individual optimistic bias and information security intent each had a simple mediating effect. Third when an individual's optimistic bias and information security intent were simultaneously input, each had a simple mediating effect. Fourth there was a double mediating effect between individual optimistic bias and information security intent. This study provided basic data for the expansion of information security model and information security education of social welfare students.

A Meta-Analysis on the Correlation between Job Satisfaction, Turnover Intention and Organizational Commitment among Nurses

  • Lee, Hong-Ki;Myoun, Sungmin
    • Journal of the Korea Society of Computer and Information
    • /
    • v.22 no.4
    • /
    • pp.115-122
    • /
    • 2017
  • The purpose of this study was to evaluate the effect of job satisfaction on turnover intention and organizational commitment in nurses through a systematic literature review and meta-analysis. For the study purpose, 26 studies were selected through a systematic process of using several databases and used to estimate the effect size of correlation between 3 variables. Meta-analysis was applied by usingcrandom effects model, and effect sizes on three types were calculated. Results are as follows. First, the effect size of correlation between job satisfaction and turnover intention is -.58. Second, the effect size of correlation between job satisfaction and organizational commitment is .77. Third, for the organizational commitment and turnover intention relationship, the effect of correlation is -0.68. Furthermore, publication bias analysis were assessed the results by using the funnel plot, Egger's regression test, fail-safe N, and trim-and-fill test. Based on these results, implications for the study were discussed.

On the Effect of Extended Human Group Scale in Perception of Group Ratio and Size at Majority-biased Social Learning (인구 집단의 스케일의 확장이 집단 비율 및 집단 크기 지각에 미치는 영향: 다수편향적 사회적 정보 활용을 중심으로)

  • Jaekyung Jang;Dayk Jang
    • Korean Journal of Cognitive Science
    • /
    • v.34 no.1
    • /
    • pp.39-66
    • /
    • 2023
  • New media moved the place of social exchange to the Internet, allowing large groups to communicate in one place beyond the limits of time and space. Recent studies have also reported cases in which human social abilities do not keep up with the expansion of group scale through social media. In this context, current study investigated how human perception of social information is affected by the expansion of the group scale in the context of majority bias. Using Internet-based task, the psychological processes that group ratio and group size are perceived and affect majority-biased social information use were investigated, and whether group scale moderates those processes was examined. The group ratio has a positive effect on the majority bias, and the relationship was partially mediated by ratio perception. Group scale did not moderate the relationship between group ratio and ratio perception. On the other hand, the correlation between group size and majority-biased social information use was not significant. Group scale moderates group size perception. The group size and size perception showed positive correlation under the smaller group scale condition. However under the extended group scale condition, the perceived group size became significantly lower and lost its correlation with group size. These results provide evidence that the psychological mechanism related to group size perception was not properly responding to the expansion of the group scale. Furthermore, the possibility of a specific psychological mechanism for processing group size information and the form of information input specifically accepted by majority bias were discussed from perspective of evolutionary psychology.

A Comparative Analysis of Patient Satisfaction and Cosmetic Outcomes after Breast Reconstruction through BREAST-Q and the Judgment of Medical Panels: Does it Reflect Well in Terms of Aesthetics in Korean Patients?

  • Choi, Woo Jung;Song, Woo Jin;Kang, Sang Gue
    • Archives of Plastic Surgery
    • /
    • v.49 no.4
    • /
    • pp.488-493
    • /
    • 2022
  • Background Currently, the BREAST-Q can effectively measure patient's satisfaction on the quality of life from the patient's perspective in relation to different type of breast reconstruction. However, evaluation of patient satisfaction and cosmetic outcomes in breast reconstruction may have potential to led bias. Methods To maximize the benefits of using BREAST-Q to evaluate clinical outcome, we performed comparative study focused on the correlation between postoperative BREAST-Q and cosmetic outcomes assessed by medical professionals. For the current analysis, we used three postoperative BREAST-Q scales (satisfaction with breast, psychosocial well-being, and sexual well-being). The Ten-Point Scale by Visser et al was applied to provide reproducible grading of the postoperative cosmetic outcomes of the breast. The system includes six subscales that measured overall aesthetic outcome, volume, shape, symmetry, scarring, and nipple-areolar complex. The photographic assessments were made by five medical professionals who were shown photographs on a computer screen in a random order. Obtained data were stored in Excel and evaluated by Spearman's correlations using SPSS Statistics. Results We enrolled 92 women in this study, 10 did not respond to all scales of postoperative BREAST-Q, the remaining 82 women had undergone breast reconstruction. The correlation between BREAST-Q score and aesthetic score measured by Ten-Point Scale for the three BREAST-Q scales all show positive values in Spearman's correlation coefficient. Conclusion A significant correlation without any bias observed was found between the patient's satisfaction measured by BREAST-Q after breast reconstruction and the medical expert's aesthetic evaluation.