• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.59 no.12
• /
• pp.2143-2149
• /
• 2010

Market price and curtailment amounts of the Demand Resource Market(DRM) are determined by competition between electricity consumers. An important aspect of the DRM involves the assessment of strategic behavior of participants for maximizing their profits. This paper presents economic equilibrium models for simulating imperfect competition among electricity consumers in the DRM and analyzes the models at Nash Equilibrium of Game Theory. The proposed demand functions and supply functions of DRM are based on the Demand Resource Market Rules in Korean electricity market. Simulation results show that the models are adequate for obtaining Nash Equilibrium of consumers' competitive curtailment.

• The Korean Journal of Applied Statistics
• /
• v.24 no.2
• /
• pp.315-321
• /
• 2011

Gene expression microarray data often include multiple missing values. Most gene expression analysis (including gene clustering analysis); however, require a complete data matric as an input. In ordinary clustering methods, just a single missing value makes one abandon the whole data of a gene even if the rest of data for that gene was intact. The quality of analysis may decrease seriously as the missing rate is increased. In the opposite aspect, the imputation of missing value may result in an artifact that reduces the reliability of the analysis. To clarify this contradiction in microarray clustering analysis, this paper compared the accuracy of clustering with and without imputation over several microarray data having different missing rates. This paper also tested the clustering efficiency of several imputation methods including our propose algorithm. The results showed it is worthwhile to check the clustering result in this alternative way without any imputed data for the imperfect microarray data.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2001.10a
• /
• pp.187-192
• /
• 2001

In this paper, a practical method to generate task strategies applicable to charmfulness and high-precision assembly, is proposed. The difficulties in devising reliable assembly strategies result form various forms of uncertainty such as imperfect knowledge on the parts being assembled and functional limitations of the assembly devices. In approach to cope with these problems, the robot is provided with the capability of learning the corrective motion in response to the force signal through iterative task execution. The strategy is realized by adopting a learning algorithm and represented in a binary tree type database. To verify the effectiveness of the proposed algorithm, a series of simulations and experiments are carried out under assimilated real production environments. The results show that the sensory signal-to-robot action mapping can be acquired effectively and, consequently, the assembly task can be performed successfully.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.255-258
• /
• 2005

A blind-mode integer frequency offset estimation algorithm is proposed for an OFDM system. Imperfect integer frequency offset estimation causes ambiguity in the data sub-carrier position. Morelli's blind integer frequency offiet estimation algorithm exploits the likelihood function by comparing the power in sub-carriers. It, however, shows performance degradation when there is the fractional frequency offset. The proposed algorithm solves this by using interpolation in the frequency domain. In this algorithm, it is exploited that the effect of the frequency offset is shown as a shift of power spectrum. By calculating the covariance of over-sampled samples, most approximate samples to integer point are obtained. It enables integer frequency offset estimation less affected by fractional frequency offset.

• East Asian Economic Review
• /
• v.21 no.2
• /
• pp.167-197
• /
• 2017

I build a small open economy (SOE) dynamic stochastic general equilibrium (DSGE) model to investigate the effect of a heterogeneous wage contract between regular and temporary workers on a macroeconomic volatility in a financially fragile economy. The imperfect financial market condition is captured by a quadratic financial adjustment cost for borrowing foreign assets, and the labor market friction is captured by a Nash bargaining process which is only available to the regular workers when they negotiate their wages with the firms while the temporary workers are given their wage which simply equals the marginal cost. As a result of impulse responsesto a domestic productivity shock, the higher elasticity of substitution between two types of workers and the lower weight on the regular workers in the firm's production process induce the higher volatilities in most variables. This is reasoned that the higher substitutability creates more volatile wage determination process while the lower share of the regular workers weakens their Nash bargaining power in the contract process.

• Journal of Korean Institute of Industrial Engineers
• /
• v.16 no.2
• /
• pp.37-44
• /
• 1990

In selecting the best project in multi-criteria decision making problems, the imperfect information of consequence and the vague preference of the decision maker(DM) would make the decision analysis more complex together with the conflict of several criteria. In this context, a method is proposed to deal the fuzzy information mentioned before instead of reducing it to a single representative value. And, based on the given imprecise information, projects are ranked completely or partially according to DM's vague preference. The procedure consists, for each pair of projects, of calculating the degree of supporting over all criteria and the degree of opposing with respect to each criterion for their outranking relation. Together with weights for each criterion, these indices produce fuzzy outranking relations for each pair of projects. And a complete or partial ranking of projects is obtained according to outranking degrees considering the interdependence among projects.

• Journal of Korean Institute of Industrial Engineers
• /
• v.16 no.2
• /
• pp.45-50
• /
• 1990

A replacement policy with repair cost limit is discussed. When a system fails, the repair cost is estimated by inspection and repair is then undertaken if the estimated cost is less than a predetermined limit L ; otherwise the system is replaced. After repair, the system is as good as new with probability(l-p) or is minimally repaired with probability p. It is assumed that repair cost can not be estimated exactly because of inspection error. When the failure time follows a Weibull distribution and repair cost a normal distribution, the value of repair cost limit minimizing the expected cost rate is shown to be finite and unique.

• Journal of Electrical Engineering and Technology
• /
• v.12 no.6
• /
• pp.2399-2410
• /
• 2017

In this paper, a linear matrix inequality-based sampled-data fuzzy observer design method is proposed based on the exact discretization approach. In the proposed design technique, a numerically relaxed observer design condition is obtained by using the discrete-time fuzzy Lyapunov function. Unlike the existing studies, the designed observer is robust to the uncertain premise variable because the fuzzy observer is designed under the imperfect premise matching condition, in which the membership functions of the system and observer are mismatched. In addition, we apply the proposed method to the state estimation problem of the attitude and heading reference system (AHRS). To do this, we derive a Takagi-Sugeno fuzzy model for the AHRS system, and validate the proposed method through the hardware experiment.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.18 no.2
• /
• pp.67-78
• /
• 1990

Though children are imperfect and immature in themselves, they have their own merits and characteristics, so that they should not be appreciated by the adult's own viewpoints. The needs of a child are obviously different from those of an adolescent or an adult. Therfore we should understand their mentality and psychology in order to give desirable outdoor space to them. In this study, children's view of outdoor environment was studied by analyzing the painting of object elementary school students of one and the other urbanizations and schooling years and different schooling years also. The data were drawn from 182 children of two different urbanization levels. The urbanization level was standardized with urban area(Taegu), and rural area(Jukjang - myon). According to the research, more area of garden was exprssed In paintings of urban children. House was expressed vy far more frequently in paintings of rural childrin than in those of urban dwellers. The children of urban expressed recreation facilities more frequently within their garden. It reflected the limitation of play space for them, As a result, the preference fur outdoor 7pare of children should by considered in Planning space for them.

• ETRI Journal
• /
• v.32 no.5
• /
• pp.810-818
• /
• 2010

This paper presents a new framework for integrating untranscribed spoken content into the acoustic training of an automatic speech recognition system. Untranscribed spoken content plays a very important role for under-resourced languages because the production of manually transcribed speech databases still represents a very expensive and time-consuming task. We proposed two new methods as part of the training framework. The first method focuses on combining initial acoustic models using a data-driven metric. The second method proposes an improved acoustic training procedure based on unsupervised transcriptions, in which word endings were modified by broad phonetic classes. The training framework was applied to baseline acoustic models using untranscribed spoken content from parliamentary debates. We include three types of acoustic models in the evaluation: baseline, reference content, and framework content models. The best overall result of 18.02% word error rate was achieved with the third type. This result demonstrates statistically significant improvement over the baseline and reference acoustic models.