• International Journal of Control, Automation, and Systems
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• v.2 no.4
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• pp.536-541
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• 2004

It is important to estimate and calibrate sensor errors in maintaining the performance level of SDINS. In this study, an estimation technique of fixed sensor errors for SDINS calibration is discussed. First, the fixed errors of gyros and accelerometers, excluding gyro biases are estimated by the navigation information of SDINS in multi-position. The SDINS with RLG includes flexure errors. In this study, the gyros flexures are out of consideration, but the proposed procedure selects certain positions and rotations in order to minimize the influence of flexures. Secondly, the influences of random walks, flexures and orientation errors are verified via numerical simulations. Thirdly, applying the previous estimated errors to SDINS, the estimation of gyro biases is conducted via the additional control signals of close-loop self-alignment. Lastly, the experiments illustrate that the extracted calibration parameters are available for the improvement of SDINS.

• Korean Journal of School Psychology
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• v.17 no.3
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• pp.263-286
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• 2020

The purpose of this study was to explore how overly positive self-estimations in peer relationships relate to subjective well-being and to the occurrence of interpersonal behaviors supporting basic psychological needs among elementary school students. This study tested the optimal margin hypothesis of positive illusion by examining the curvilinear relationship between these variables. The sample consisted of 346 fifth and sixth grade students. The self-criterion residual method was used to derive self-estimation bias scores by regressing the real peer relations index (i.e., In-degree) on their perceived peer relationship qualities. The results showed that girls more strongly overestimated the quality of their peer relationships than boys. Self-estimation biases had a positive curvilinear relationship with negative affects and a negative curvilinear relationship with relatedness needs supporting interpersonal behaviors. These results supported the existence of the optimal margin of positive illusion because overestimations of the quality of peer relationships were associated with lower levels of negative affects and relatedness needs-supporting interpersonal behaviors, though these benefits flattened out and no further benefit was observed after an optimal level of overestimation. However, self-estimation bias was linearly associated with positive affect, autonomy needs-supporting interpersonal behaviors, and competence needs-supporting interpersonal behaviors. These results indicated that optimal margin hypothesis was not supported for all outcome variables.

• Journal of Preventive Medicine and Public Health
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• v.49 no.1
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• pp.45-52
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• 2016

Objectives: Previous large-scale cohort studies conducted in Korea have found a positive association between diabetes mellitus (DM) and colorectal cancer (CRC) in men only, in contrast to studies of other populations that have found significant associations in both men and women. Methods: A total of 1070 CRC cases and 2775 controls were recruited from the National Cancer Center, Korea between August 2010 and June 2013. Self-reported DM history and the duration of DM were compared between cases and controls. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by binary and polytomous logistic regression models. Results: DM was associated with an elevated risk of CRC in both men (OR, 1.47; 95% CI, 1.13 to 1.90) and women (OR, 1.92; 95% CI, 1.24 to 2.98). This association remained when we controlled for age, body mass index, alcohol consumption, and physical activity level. In sub-site analyses, DM was associated with distal colon cancer risk in both men (multivariate OR, 2.04; 95% CI, 1.39 to 3.00) and women (multivariate ORs, 1.99; 95% CI, 1.05 to 3.79), while DM was only associated with rectal cancer risk in women (multivariate OR, 2.05; 95% CI, 1.10 to 3.82). No significant association was found between DM and proximal colon cancer risk in either men (multivariate OR, 1.45; 95% CI, 0.88 to 2.41) or women (multivariate OR, 1.79; 95% CI, 0.78 to 4.08). Conclusions: Overall, DM was associated with an increased risk of CRC in Koreans. However, potential over-estimation of the ORs should be considered due to potential biases from the case-control design.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5D
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• pp.605-610
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• 2009

The either satisfaction levels or limits of tolerance levels felt by the users in the certain space/region should be examined for measuring social capacity on the total amount of vehicles. The reliability of measuring social carrying capacity depends primarily on decreasing the strategic responding biases. To induce the honest responses to preferences, Dichotomous Choice which is specifically known as the Double-Bounded Dichotomous Choice was adopted in this research to suggest the measurement methodology of social carrying capacity on the total amount of vehicles in U-do island. The empirical test was carried out the U-do island, an administrative district of Jeju Special Self-Governing Province. The number of vehicles satisfied by the 10% of residents was 390 and the satisfactory vehicle number was decreased to 132 extended to 90% of residents. This research, based on the political decision making criteria, set up the social carrying capacity in U-do island. The vehicle number satisfied by 50% of residents was 227, which meant the same number of residents turn to be supporter in case of political actions.