• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.4
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• pp.243-250
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• 2005

Test methodology is diversity by devices and the number of test pattern is tremendous because the digital circuit includes TTL and CMOS family ICs as well as high density devices such as ROM and RAM. Accordingly, the quick and effective test strategy is required to enhance the test productivity. This paper proposes the test strategy which is able to be applied efficiently to the diversity devices on the digital circuit board by analyzing the structure and characteristic of the digital device. Especially, this test strategy detects the faulted digital device or the faulted digital circuit on the digital board using SSA(Serial Signature Analysis) technique based on the polynomial division theory The SSA technique identifies the faults by comparing the reminder from good device with reminder from the tested device. At this time, the reminder is obtained by enforcing the data stream obtained from output pins of the tested device on the LFSR(Linear Feedback Shift Register) representing the characteristic equation. Also, the method to obtain the optimal signature analysis circuit is explained by furnishing the short bit input streams to the long bit input streams to the LFSR having 8, 12, 16, 20bit input/output pins and by analyzing the occurring probability of error which is impossible to detect. Finally, the effectiveness of the proposed test strategy is verified by simulating the stuck at 1 errors or stuck at 0 errors for several devices on typical 8051 digital board.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.165-170
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• 2002

For the inaccessible area where the field verification is unable, it is difficult to obtain the ground control points (GCPs) or the acquired GCPs may be inaccurate. In general systematic geometric correction is achieved by utilizing orbit ephemeris and three axis attitude data of the satellite. however, this method results to poor accuracy of the imagery's absolute coordinates. To improve the absolute accuracy as well as the relative accuracy, we added the accessible region into the inaccessible area. We obtained GCPs in the accessible region by the fast static GPS survey and made geometric corrections with these biased GCPs. Because the biased GCPs show a pattern of coordinate errors, we analyzed this tendency to track the estimated errors in the inaccessible area.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.6
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• pp.267-275
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• 2013

EKF has been widely used for GPS/INS integration as standard method but EKF has one well-known drawback. if the errors are not within the bounded region, the filter may be divergent. The particle filter has the advantage of the nonlinear and non-gaussian system. This paper proposes a method for compensating the GPS position errors based on the particle filter and presents loosely-coupled GPS/INS integration using proposed algorithm. We used GPS position pattern with particle filter and added attitude kalman filter for improving attitude accuracy. To verify the performance, the proposed method is compared with high cost GPS as reference. In the experimental result, we verified that the accuracy and robust were well improved by the proposed method filter effectively and robustness than by original loosely-coupled integration when vehicle turns at corner.

• Journal of Mechanical Science and Technology
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• v.19 no.10
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• pp.1919-1931
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• 2005

Human joint motion can be kinematically described in three planes, typically the frontal, sagittal, and transverse, and related to experimentally measured data. The selection of reference systems is a prerequisite for accurate kinematic analysis and resulting development of the equations of motion. Moreover, the development of analysis techniques for the minimization of errors, due to skin movement or body deformation, during experiments involving human locomotion is a critically important step, without which accurate results in this type of experiment are an impossibility. The traditional kinematic analysis method is the Angular-based method (ABM), which utilizes the Euler angle or the Bryant angle. However, this analysis method tends to increase cumulative errors due to skin movement. Therefore, the objective of this study was to propose a new kinematic analysis method, Position-based method (PBM), which directly applies position displacement data to represent locomotion. The PBM presented here was designed to minimize cumulative errors via considerations of angle changes and translational motion between markers occurring due to skin movements. In order to verify the efficacy and accuracy of the developed PBM, the mean value of joint dislocation at the knee during one gait cycle and the pattern of three dimensional translation motion of the tibiofemoral joint at the knee, in both flexion and extension, were accessed via ABM and via new method, PBM, with a Local Reference system (LRS) and Segmental Reference system (SRS), and then the data were compared between the two techniques. Our results indicate that the proposed PBM resulted in improved accuracy in terms of motion analysis, as compared to ABM, with the LRS and SRS.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.1
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• pp.84-93
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• 2018

In this paper, we propose an Elman recurrent neural network to predict and analyze a time series of power energy consumption. To this end, we consider the volatility of the time series and apply the sample variance and the detrended fluctuation analyses to the volatilities. We demonstrate that there exists a correlation in the time series of the volatilities, which suggests that the power consumption time series contain a non-negligible amount of the non-linear correlation. Based on this finding, we adopt the Elman recurrent neural network as the model for the prediction of the power consumption. As the simplest form of the recurrent network, the Elman network is designed to learn sequential or time-varying pattern and could predict learned series of values. The Elman network has a layer of "context units" in addition to a standard feedforward network. By adjusting two parameters in the model and performing the cross validation, we demonstrated that the proposed model predicts the power consumption with the relative errors and the average errors in the range of 2%~5% and 3kWh~8kWh, respectively. To further confirm the experimental results, we performed two types of the cross validations designed for the time series data. We also support the validity of the model by analyzing the multi-step forecasting. We found that the prediction errors tend to be saturated although they increase as the prediction time step increases. The results of this study can be used to the energy management system in terms of the effective control of the cross usage of the electric and the gas energies.

• Journal of The Korean Association For Science Education
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• v.17 no.4
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• pp.525-540
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• 1997

The present study tested the hypothesis that maturation of the prefrontal lobes is a crucial factor determining the performance of scientific reasoning tasks, Functions of the prefrontal lobes, such as activating relevant information, sequential planning and monitoring, and inhibiting irrelevant information, are related thinking patterns with scientific reasoning. Therefore, we inferred the idea that the prefrontal lobes play an important role in scientific reasoning. To test the hypothesis. the present study investigated a prefrontal lobe patient's task solving procedures in scientific reasoning tasks and the correlation and regression analysis between a test of prefrontal lobe function and two scientific reasoning tasks, The perseverative errors in the Wisconsin Card Sorting Test(WCST) was used as a measure of the prefrontal lobe function, The Melinark Type Task and the Classroom Test of Scientific Reasoning were used as measures of scientific reasoning abilities. Ages and Group Embedded Figure Test were also used as measures of two alternative hypotheses, general maturation and field independency respectively. The prefrontal lobe patient showed a crucial deficiency in solving scientific reasoning tasks. In the tasks, the patient could not used the reasoning of If... and... then... therefore pattern. In correlation study, the perseveration errors of the WCST showed a significantly negative correlation with two scientific reasoning tasks. Multiple regression study also showed that the perseveration errors measured as a function of the prefrontal lobes have more contribution to scientific reasoning ability than contributions of alternative hypotheses. Therefore, the present study supported the hypothesis that prefrontal lobes play a crucial role in scientific reasoning ability, What function of the prefrontal lobes do play crucial role in scientific reasoning? The present study provided an explanation for the question, which inhibiting ability of the prefrontal lobes is responsible for the scientific reasoning ability, in a part at least. That is, perseverative tendency in task-solving procedures causes a deficiency of an ability to inhibit the wrong information to solve a task. The present study provided a possibility of neuropsychological approach in science education research. The present study also showed an importance of the prefrontal lobe development in the performance of scientific reasoning task.

• Journal of Elementary Mathematics Education in Korea
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• v.11 no.2
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• pp.199-216
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• 2007

The purpose of the present study was to analyze the types of errors made by students in the figure domain at the stages of first and second semester of 4th grade in elementary school that include the definition and the properties of figure, to identify the causes of such errors, and to help the teaching of the 4th grade figure domain. When the trends of errors were analyzed for each question, the most common error was the wrong use of theorems or definitions, and its main causes were student's low level in geometry and limited concept images. Thus, it is necessary to make them have clear understanding of these concepts and terms and students need to do various activities suitable for their level in geometry. In addition, figure images presented in the mathematics textbooks and the mathematics practice book have limitations. Thus, figures of various positions and lengths should be presented and described accurately, and the books should be redesigned for various practical activities.

• Magazine of the Korean Society of Agricultural Engineers
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• v.34 no.2
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• pp.73-84
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• 1992

The TIDE, finite element model for the simulation of tidal flow in shallow sea was tested for its applicability at the Saemangeum area. Several pre and post processors were developed to facilitate handling of the complicated and large amount of input and output data for the model developed. Also an operation scheme to run the model and the processors were established. As a result of calibration test using the observed data collected at 9 points within the region, linearlized friction coefficients were adjusted to be ranged 0.0027~0.0072, and water depths below the mean sea level at every nodes were changed to be increased generally by 1 meter. Comparisons of tidal velocities between the observed and the simulated for the 5 stations were made and obtained the result that the average relative error between simulated and observed tidal velocities was 11% for the maximum velocities and 22% for the minimum, and the absolute errors were less than 0.2m/sec. Also it was found that the average R.M.S. error between the velocities of observed and simulated was 0.119 m/sec and the average correlation coefficient was 0.70 showing close agreement. Another comparison test was done to show the result that R.M.S. error between the simulated and the observed tidal elevations at the 4 stations was 0.476m in average and the correlation coefficients were ranged 0.96~0.99. Though the simulated tidal circulation pattern in the region was well agreed with the observed, the simulated tidal velocities and elevations for specific points showed some errors with the observed. It was thought that the errors mainly due to the characteristics of TIDE Model which was developed to solve only with the linearized scheme. Finally it was concluded that, to improve the simulation results by the model, a new attempt to develop a fully nonlinear model as well as further calibration and the more reasonable generation of finite element grid would be needed.

• Journal of the Korean School Mathematics Society
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• v.15 no.4
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• pp.699-718
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• 2012

The purpose of mathematics eduction is to develop the ability of thinking mathematically. It informs method to solve problem through mathematical thinking that teach mathematical ability. Errors in the problem solving can be thought as those in the mathematical thinking. Therefore analysis and classification of mathematics errors is important to teach mathematics. This study researches the preceding studies on mathematics errors and presents the characteristic of them with analyzed models. The results achieved by analysis of the process of problem solving are as follows : ▸ Students feel much harder to solve words problems rather than multiple-choice problems. ▸ The length of sentence make some differences of understanding of the words problems. Students easy to understand short sentence problems than long sentence problems. ▸ If students feel difficulties on the pre-learned mathematical content, they feel the same difficulties on the words problems based on the pre-learned mathematics content.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.1
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• pp.57-62
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• 2004

We have proposed an efficient method of word separation in a handwritten legal amount on bank check based on the spatial gaps between the connected components. The previous gap measures all suffer from the inherent problem of underestimation or overestimation that causes a deterioration in separation performance. In order to alleviate such burden, we have developed a modified version of each distance measure. Also, 4 class clustering based method of integrating three different types of distance measures has been proposed to compensate effectively the errors in each measure, whereby further improvement in performance of word separation is expected. Through a series of word separation experiments, we found that the modified distance measures show a better performance with over 2 - 3% of the word separation rate than their corresponding original distance measures. In addition, the proposed combining method based on 4-class clustering achieved further improvement by effectively reducing the errors common to two of three distance measures as well as the individual errors.