• International Journal of Control, Automation, and Systems
• /
• 제5권3호
• /
• pp.329-336
• /
• 2007

This paper considers a fault accommodation problem for inertial navigation systems (INS) that have redundant inertial sensors such as gyroscopes and accelerometers. It is wellknown that the more sensors are used, the smaller the navigation error of INS is, which means that the error covariance of the position estimate becomes less. Thus, when it is decided that double faults occur in the inertial sensors due to fault detection and isolation (FDI), it is necessary to decide whether the faulty sensors should be excluded or not. A new accommodation rule for double faults is proposed based on the error covariance of triad-solution of redundant inertial sensors, which is related to the navigation accuracy of INS. The proposed accommodation rule provides decision rules to determine which sensors should be excluded among faulty sensors. Monte Carlo simulation is performed for dodecahedron configuration, in which case the proposed accommodation rule can be drawn in the decision space of the two-dimensional Cartesian coordinate system.

• Journal of the Korea Society of Computer and Information
• /
• 제17권10호
• /
• pp.25-33
• /
• 2012

In this paper, we propose a rule-based model to correct errors in a speech recognition result in the mobile device environment. The proposed model considers the mobile device environment with limited resources such as processing time and memory, as follows. In order to minimize the error correction processing time, the proposed model removes some processing steps such as morphological analysis and the composition and decomposition of syllable. Also, the proposed model utilizes the longest match rule selection method to generate one error correction candidate per point, assumed that an error occurs. For the purpose of deploying memory resource, the proposed model uses neither the Eojeol dictionary nor the morphological analyzer, and stores a combined rule list without any classification. Considering the modification and maintenance of the proposed model, the error correction rules are automatically extracted from a training corpus. Experimental results show that the proposed model improves 5.27% on the precision and 5.60% on the recall based on Eojoel unit for the speech recognition result.

• Journal of IKEEE
• /
• 제7권1호
• /
• pp.97-106
• /
• 2003

In ARQ based error control, imperfect error detection leaves error remains on a packet. Aiming for a reduction of error remains in multicopy transmission ARQ system, we propose a rule of requesting a retransmission and deciding a correct copy, (identified as $(m, \;{\sigma})$rule). While the probability of error remains is reduced by the employment of the $(m, \;{\sigma})$ rule at multicopy transmission ARQ, delay and throughput performance may be degraded in comparison with those of conventional single copy transmission ARQ. Thus, we develop an analytical method to evaluate the performance trade-off in multicopy transmission ARQ following the $(m, \;{\sigma})$ rule. From the numerical results obtained by the analytical method, we investigate the effect of channel characteristics on the performance of error remains, packet loss, throughput, and packet delay, and confirm that the adaptability of the $(m, \;{\sigma})$ rule to conform to various QoS requirements with ease.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• 제4권1호
• /
• pp.22-26
• /
• 2003

Overlap Errors and side-lobes have been simultaneously solved by the rule-based correction using the rules extracted from test patterns. Lithography process parameters affecting attPSM lithography process have been determined by the fitting method to the real process data. The correction using scattering bars has been compared to the Cr shield method. The optimal insertion rule of the scattering bal's has made it possible to suppress the side-lobes and to enhance DOF at the same time. Therefore, in this paper, the solution to both side-lobe and overlap Error has been proposed using rule-based confection. Compared to the existing Cr shield method, the proposed rule-based correction with scattering bars can reduce the process complexity and time for mask production.

• Communications for Statistical Applications and Methods
• /
• 제2권2호
• /
• pp.146-154
• /
• 1995

By using simple Taylor expansion, we derive an easy bias-correction rule for the apparent prodiction error of the predictor defined by the general M-estimators with respect to an arbitrary measure of prediction error. Our method has a considerable computational advantage over the previous methods based on the resampling thchnique such as Cross-validaton and Boothtrap. Connections with AIC, Cross-Validation and Boothtrap are discussed too.

• Journal of the Korean Statistical Society
• /
• 제16권1호
• /
• pp.26-36
• /
• 1987

In this paper, we study on a subset selection procedure based on Hodges-Lehmann estimators derived from the Wilcoxon test. To estimate the standard error of the Hodges-Lehmann estimators, the biweight A-estimator of scale is used. The Pitman efficiency of the proposed rule is compared with the Gupta's rule and the trimmed-means rule through a small-sample Monte Carlo study. The results show that the proposed rule satisfies the $P^*$-condition and is very efficient in various heavy-tailed distributions.

• Journal of Navigation and Port Research
• /
• 제42권3호
• /
• pp.159-166
• /
• 2018

The identification of behavioral errors by seafarers that have caused marine accidents may provide important clues for the reduction or prevention of marine accidents. The purpose of this study is to identify the behavioral errors of seafarers by the type of marine accident using the theory of Skill-, Rule-, and Knowledge-Based Behavior (SRKBB). In order to identify behavioral errors, we collected the information related to 1,744 cases of maritime accidents over a 9 year period (2008 ~ 2016). The behavior errors of the seafarers who caused the marine accidents were classified as SBBE (Skill-Based Behavioral Error), RBBE (Rule-Based Behavioral Error), and KBBE (Knowledge-Based Behavioral Error). After analyzing the frequency of behavioral errors according to the type of marine accident, results showed SBBE had the highest frequency of errors, followed by RBBE. Additionally, the frequency of occurrence of accidents such as stranding, overturning, and sinking was high in KBBE. This study showed it is possible to identify behavioral errors of seafarers according to the type of marine accidents.

• ETRI Journal
• /
• 제15권2호
• /
• pp.35-51
• /
• 1993

This paper presents function approximation based on nonparametric estimation. As an estimation model of function approximation, a three layered network composed of input, hidden and output layers is considered. The input and output layers have linear activation units while the hidden layer has nonlinear activation units or kernel functions which have the characteristics of bounds and locality. Using this type of network, a many-to-one function is synthesized over the domain of the input space by a number of kernel functions. In this network, we have to estimate the necessary number of kernel functions as well as the parameters associated with kernel functions. For this purpose, a new method of parameter estimation in which linear learning rule is applied between hidden and output layers while nonlinear (piecewise-linear) learning rule is applied between input and hidden layers, is considered. The linear learning rule updates the output weights between hidden and output layers based on the Linear Minimization of Mean Square Error (LMMSE) sense in the space of kernel functions while the nonlinear learning rule updates the parameters of kernel functions based on the gradient of the actual output of network with respect to the parameters (especially, the shape) of kernel functions. This approach of parameter adaptation provides near optimal values of the parameters associated with kernel functions in the sense of minimizing mean square error. As a result, the suggested nonparametric estimation provides an efficient way of function approximation from the view point of the number of kernel functions as well as learning speed.

• The Transactions of the Korea Information Processing Society
• /
• 제7권7호
• /
• pp.2169-2178
• /
• 2000

This paper proposes the structure of an agent and rules for fault detection and location on LAN. To find out a reason of critical fault incurred LAN, collision detection rule, error detection rule, broadcast detection rule, system location rule, and Internet application location rule ar shown. Also, the structure of multi-agent system and state transition diagram is portrayed to have connectivity with he set of rules. To verify availability of proposed rules, the process to find a faulty system is shown by monitoring and analyzing the LAN fault occurrences from the proposed set of rules. Such an rule based agent system is helpful to an Internet manager to solve a reason of fault and make ad decision from gathering management information.

• Journal of the Korean Institute of Telematics and Electronics B
• /
• 제31B권8호
• /
• pp.211-218
• /
• 1994

In this paper we develope a hybrid learning rule to improve the robustness of multi-layer Perceptions. In most neural networks the activation of a neuron is deternined by a nonlinear transformation of the weighted sum of inputs to the neurons. Investigating the behaviour of activations of hidden layer neurons a new learning algorithm is developed for improved robustness for multi-layer Perceptrons. Unlike other methods which reduce the network complexity by putting restrictions on synaptic weights our method based on error-backpropagation increases the complexity of the underlying proplem by imposing it saturation requirement on hidden layer neurons. We also found that the additional gradient-descent term for the requirement corresponds to the Hebbian rule and our algorithm incorporates the Hebbian learning rule into the error back-propagation rule. Computer simulation demonstrates fast learning convergence as well as improved robustness for classification and hetero-association of patterns.