• The Journal of Korean Institute of Communications and Information Sciences
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• v.25 no.7A
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• pp.1063-1075
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• 2000

This paper proposes an adaptive error concealment technique for compressed video. Since redundancy is extracted out during compression process, compressed video is vulnerable to errors which occur during transmission of video over error prone networks such as wireless channels and Internet. Error concealment is a process of reconstructing video out of damaged video bit stream. We proved that scalable encoding is very useful for error concealment. Analysis of experiments shows that some part of image is better concealed by using base layer information and other part of image is better concealed by using previous frame information. We developed a technique which enables to decide which methodology is more effective, adaptively, based on motion vectors and regional spatial activity. We used H.263v2 for scalable encoding, but, our approach could be applied to all DCT based video codec.

• The KIPS Transactions:PartD
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• v.14D no.2
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• pp.217-224
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• 2007

In order to determine the value and type statically. CTOC uses the SSA Form which separates the variable according to assignment. The SSA Form is widely being used as the intermediate expression of the compiler for data flow analysis as well as code optimization. However, the conventional SSA Form is more associated with variables rather than expressions. Accordingly, the redundant expressions are eliminated to optimize expressions of the SSA From. This paper defines the partial redundant expression to obtain a more optimized code and also implements the technique for eliminating such expressions.

• Journal of Digital Convergence
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• v.11 no.11
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• pp.343-349
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• 2013

Rough set theory comes to derive optimal rules through the effective selection of features from the redundancy of lots of information in data mining using the concept of equivalence relation and approximation space in rough set. The reduction of attributes is one of the most important parts in its applications of rough set. This paper purports to define a information-theoretic measure for determining the most important attribute within the association of attributes using rough entropy. The proposed method generates the effective reduct set and formulates the core of the attribute set through the elimination of the redundant attributes. Subsequently, the control rules are generated with a subset of feature which retain the accuracy of the original features through the reduction.

• Steel and Composite Structures
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• v.11 no.4
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• pp.273-290
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• 2011

In current ductility-based earthquake-resistant design, the estimation of design forces continues to be carried out with the application of response modification factors on elastic design spectra. It is well-known that the response modification factor (R) takes into account the force reduction, strength, redundancy, and damping of structural systems. The key components of the response modification factor (R) are force reduction ($R_{\mu}$) and strength ($R_S$) factors. However, the response modification and strength factors for structural systems presented in design codes were based on professional judgment and experiences. A numerical study has been accomplished to evaluate force reduction, strength, and response modification factors for special steel moment resisting frames. A total of 72 prototype steel frames were designed based on the recommendations given in the AISC Seismic Provisions and UBC Codes. Number of stories, soil profiles, seismic zone factors, framing systems, and failure mechanisms were considered as the design parameters that influence the response. The effects of the design parameters on force reduction ($R_{\mu}$), strength ($R_S$), and response modification (R) factors were studied. Based on the analysis results, these factors for special steel moment resisting frames are evaluated.

• IE interfaces
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• v.22 no.2
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• pp.126-134
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• 2009

As product quality and yield are essential factors in semiconductor manufacturing, monitoring the main manufacturing steps is a critical task. For the purpose, FDC(Fault detection and classification) is used for diagnosing fault states in the processes by monitoring data stream collected by equipment sensors. This paper proposes an FDC model based on decision tree which provides if-then classification rules for causal analysis of the processing results. Unlike previous decision tree approaches, we reflect the structural aspect of the data stream to FDC. For this, we segment the data stream into multiple subregions, define structural features for each subregion, and select the features which have high relevance to results of the process and low redundancy to other features. As the result, we can construct simple, but highly accurate FDC model. Experiments using the data stream collected from etching process show that the proposed method is able to classify normal/abnormal states with high accuracy.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.1-8
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• 2006

The Steer-By-Wire(SBW) system replaces complex mechanical linkages of the current steering system with electric motors, sensors, and electronic control units. However, the SBW system should guarantee its safety and reliability before commercialization, and therefore, a reliable and robust fault-tolerant technology has to be implemented. This paper proposes a fault-tolerant control algorithm for the SBW system. Based on careful analysis on propagation effects of sensor faults, a reliable fault-tolerant control strategy has been developed. The fault-tolerant controller consists of a fault detection part that monitors and detects faults in the steering wheel and road wheel sensors, and a reconfiguration part that switches to normal sensor signal based on fault detection information. It has been demonstrated by simulation that the proposed algorithm detects sensor faults accurately and enables reliable steering control under various dynamic fault situations.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.6
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• pp.587-598
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• 2013

In Korea military (KM), various military supplies are distributed to individual military units via three different multi-tier supply networks owned and operated by army, navy, and air force, respectively. Under the current supply networks, the chances for the occurrence of delayed supply, undersupply, and oversupply increase, and supply redundancy also can become a problem. Thus, KM is now trying to improve its current multi-tier supply networks by constructing logistics consolidation centers. Private companies operate logistics consolidation centers to effectively manage various types of inventories before delivering them to final customers. In this paper, we newly propose a mathematical model for building the optimized military supply network considering adopting the military logistics consolidation centers. Based on the real situation of KM, the proposed model was validated in terms of its feasibility, and it seems that the outcome (the location of the military logistics consolidation centers) of the proposed model can be one of the good alternatives for KM.

• The Transactions of the Korea Information Processing Society
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• v.6 no.12
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• pp.3662-3674
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• 1999

This paper addresses some design issues for establishing the optimal number of spare units in array systems manufactured using fault-tolerant multichip modules(MCM's) for massively parallel computing(MPC). We propose a new quantitative approach to an optimal cost-effective MCM system design under yield and reliability constraints. In the proposed approach, we analyze the effect of residual redundancy on operational reliability of fault-tolerant MCM's. In particular, the issues of imperfect support circuitry, chip assembly yield and array topology are investigated. Extensive parametric results for the analysis are provided to show that our scheme can be applied to design ways using MCM's for MPC applications more efficiently, subject to yield and reliability constraints.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.7 no.2
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• pp.1-6
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• 1989

The adjustment of levelling net is being done to the order of nets independently by using the least square method. For the small size net, it has difficulties in verification and statistical analysis of the net since the degree of freedom is low At the same time, it is also difficult to evaluate the error of lower order net correctly. The aim of this study is to analyse the properties of combined adjustment method compared with the independent adjustment method by using the data which have been measured during 1967-1987. Another aim is to analyse the influences of normal orthometric correction and changes of datum. Finally, Korean leveling net has been evaluated by applying real redundancy and variance component estimation.

• Journal of Information Technology Services
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• v.14 no.4
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• pp.237-256
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• 2015

The purpose of this study is to develop the eTextbook and to explore the usability of the eTextbook for accelerating mobile learning in university. This study was primarily based on needs analysis of students, and eTextbook was created based on digital publishing through Adobe DPS. The major design principles of the eTextbook based on previous studies were as follow. First, eTextbook should deliver learning contents in a simple and systematic way. Second, eTextbook should induce student's flows by providing segmented learning contents and various learning resources. Third, eTextbook should expand information accessibility by providing a wide variety of multimedia functions. The development principles of eTextbook have been developed based on cognitive psychology. Location and function of the link or icon used for eTextbook have been developed on the basis of the principles of cognitive psychology. The main development principles were Coherence, Signaling, Redundancy, Segmentation, Multimedia principle, and so on. In order to examine usability of the developed eTextbook, experts' and learners' reactions were evaluated. The primary responses of learners are that the eTextbook increased the learning accessibility and provided various multimedia factors, and thus increased the learning flows in the class.