• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.39-45
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• 2021

This paper discusses how to handle incomplete data including missing values. Optimally processing the missing value means obtaining an estimate that is the closest to the original value from the information contained in the training data, and replacing the missing value with this value. The way to achieve this is to use a decision tree that is completed in the process of classifying information by the classifier. In other words, this decision tree is obtained in the process of learning by inputting only complete information that does not include loss values among all training data into the C4.5 classifier. The nodes of this decision tree have classification variable information, and the higher node closer to the root contains more information, and the leaf node forms a classification region through a path from the root. In addition, the average of classified data events is recorded in each region. Events including the missing value are input to this decision tree, and the region closest to the event is searched through a traversal process according to the information of each node. The average value recorded in this area is regarded as an estimate of the missing value, and the compensation process is completed.

• Korean Journal of Computational Design and Engineering
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• v.12 no.5
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• pp.330-343
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• 2007

In this paper, we present a new surface content completion system that can effectively repair both shape and appearance from scanned, incomplete point set inputs. First, geometric holes can be robustly identified from noisy and defective data sets without the need for any normal or orientation information. The geometry and texture information of the holes can then be determined either automatically from the models' context, or manually from users' selection. After identifying the patch that most resembles each hole region, the geometry and texture information can be completed by warping the candidate region and gluing it onto the hole area. The displacement vector field for the exact alignment process is computed by solving a Poisson equation with boundary conditions. Out experiments show that the unified framework, founded upon the techniques of deformable models and PDE modeling, can provide a robust and elegant solution for content completion of defective, complex point surfaces.

• Journal of the Korean Data and Information Science Society
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• v.17 no.3
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• pp.919-925
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• 2006

Maximum likelihood estimate(MLE) is obtained from the partial log-likelihood function for the cell probabilities of two way incomplete contingency tables proposed by Chen and Fienberg(1974). The partial log-likelihood function is modified by adding lagrangian multiplier that constraints can be incorporated with. Variances of MLE estimators of population proportions are derived from the matrix of second derivatives of the loglikelihood with respect to cell probabilities. Simulation results, when data are missing at random, reveal that Complete-case(CC) analysis produces biased estimates of joint probabilities under MAR and less efficient than either MLE or MI. MLE and MI provides consistent results under either the MAR situation. MLE provides more efficient estimates of population proportions than either multiple imputation(MI) based on data augmentation or complete case analysis. The standard errors of MLE from the proposed method using lagrangian multiplier are valid and have less variation than the standard errors from MI and CC.

• Journal of the Korea Society of Computer and Information
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• v.20 no.6
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• pp.51-58
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• 2015

This paper suggests assignment-swap algorithm with time complexity O(mn) to obtain the optimal solution for large-scale of transportation problem (TP) with incomplete cost lists. Generally, the TP with complete cost lists can be solved with TSM (Transportation Simplex Method). But, we can't be solved for large-scale of TP with TSM. Especially. It is hard to solve for large-scale TP with incomplete cost lists using TSM. Therefore, experts simply using commercial linear programming package. Firstly, the proposed algorithm applies assignment strategy of transportation quantity to ascending order of transportation cost. Then, we reassign from surplus of supply to shortage of demand. Secondly, we perform the 2-opt and 1-opt swap optimization to obtain the optimal solution. Upon application to $31{\times}15$ incomplete cost matrix problem, the proposed assignment-swap algorithm more improves the solution than LINGO of commercial linear programming.

• Clinical and Experimental Pediatrics
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• v.56 no.9
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• pp.389-395
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• 2013

Purpose: This single-center study was conducted to assess the changes in epidemiological and clinical characteristics and outcomes of patients with Kawasaki disease (KD) over the past 7 years. Methods: This retrospective study included 135 children with KD, admitted to Chungnam National University Hospital, Daejeon, between 2004 and 2005 (group A, n=53) and between 2011 and 2012 (group B, n=82). Medical records were reviewed to obtain information regarding the presenting signs and symptoms, demographic characteristics, and laboratory and echocardiographic findings associated with KD. Results: The hospital admission date after onset was significantly earlier in group B than in group A (P=0.008). The proportion of patients with incomplete KD was 45.3% and 65.9% in group A and B, respectively (P=0.018). The number of pretreatment coronary artery lesions (CALs) were significantly lesser in group B than in group A. (10/53 vs. 5/82, P=0.021). No significant differences was observed in the incidence of CALs at discharge, febrile phase duration, hospital stay duration, incidence of retreatment, and intravenous immunoglobulin dose between 2 groups. The total febrile phase was shorter in patients with incomplete KD than in those with complete KD in both groups. Conclusion: The proportion of incomplete KD has become higher. Furthermore, early admission and management of patients with KD may be related to increased incomplete KD and decreased CALs. Therefore, we believe that a diagnostic strategy for incomplete KD should be established regardless of the presence of coronary lesions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.11B
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• pp.700-708
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• 2007

This paper considers an incentive regulation in the telecommunications industry with respect to the sale of retail and access services. This regulation scheme induces the monopoly carrier who owns bottleneck facilities to adopt socially optimal outcomes when providing access and retail services. It is well known that upstream carriers can realize an integrated level of profit, without integration, by means of a two-part tariff. First, this paper introduces a framework for regulating an access and retail price combined with budget balancing. Second, this paper introduces two-part tariff (price discrimination) scheme for both access (upstream) and retail (downstream) services and discusses the resulting implications for incentive regulation when the regulator has incomplete information about cost functions. By imposing a self-selection mechanism, the regulator can induce firms to adopt socially optimal prices in both access and retail markets.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.14 no.2
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• pp.107-113
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• 2014

The derivation of optimal information from decision table is based on the concept of indiscernibility relation and approximation space in rough set. Because decision table is more likely to be susceptible to the superposition or inconsistency in decision table, the reduction of attributes is a important concept in knowledge representation. While complete subsets of the attribute's domain is considered in algebraic definition, incomplete subsets of the attribute's domain is considered in information-theoretic definition. Therefore there is a marked difference between algebraic and information-theoretic definition. This paper proposes a conditional entropy using rough set as information theoretical measures in order to deduct the optimal information which may contain condition attributes and decision attribute of information system and shows its effectiveness.

• International Area Studies Review
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• v.15 no.1
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• pp.59-86
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• 2011

This paper examines a country's strategic optimal tariff policy against a foreign firm with market power. That is, the purpose of the paper is, under asymmetric information, to reexamine the problem of optimal tariff policy against a foreign monopolist from another country's welfare standpoint. This is to extend the analysis of Brander and Spencer(1984) which is both analytic and elaborate. The incentive compatible tariff schedule is derived, and then policy implications are investigated. The main result is that, under incomplete information, the optimal tariff is elevated above its full-information counterpart in order to capture foreign rents. Moreover, it suggests that trade policies motivated by rent extraction are unlikely to be robust to the introduction of incomplete information. This research complements an existing literature on the strategic trade policy in terms of asymmetric information.

• Journal of Labour Economics
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• v.38 no.4
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• pp.83-107
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• 2015

Free Agent(FA) system allows a professional player to make a salary contract with the other clubs as well as the incumbent one after the player has played in one club for a fixed periods. Sometimes compared with the salary FA players performs very poorly, which leads to a debate about FA busts. We extend the model of Yang and Wang(2013) to the one with incomplete information about the productivity of the player to explain the possibility of FA busts. FA busts do not arise in the separating equilibrium where the private information is fully revealed. The FA busts do occur in the pooling equilibrium We show that the separating equilibrium does not exist. We also show that under some conditions, in particular with strong compensation rule, the unique pooling equilibrium exists.

• The Korean Journal of Financial Management
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• v.8 no.2
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• pp.165-208
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• 1991

This paper develops an intertemporal general equilibrium model of asset pricing with taxes under the noisy and the incomplete information structure and examines theoretically the stochastic behavior of general equilibrium asset prices in a one-good, production, and exchange economy in continuous time markets. The important features of the model are its integration of real and financial markets and the analysis of the effects of differential tax rates between ordinary income and capital gains. The model developed here can provide answers to a wide variety of questions about stochastic structure of asset prices and the effect of tax on them.