• Journal of the Semiconductor & Display Technology
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• v.12 no.1
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• pp.1-7
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• 2013

Grey-level statistical models have been widely used in many applications for object location and identification. However, conventional models yield some problems in model refinement when training images are not properly aligned, and have difficulties for real-time recognition of arbitrarily rotated models. This paper presents improved grey-level statistical models that align training images using image or feature matching to overcome problems in model refinement of conventional models, and that enable real-time recognition of arbitrarily rotated objects using efficient hierarchical search methods. Edges or features extracted from a mean training image are used for accurate alignment of models in the search image. On the aligned position and orientation, fitness measure based on grey-level statistical models is computed for object recognition. It is demonstrated in various experiments in PCB inspection that proposed methods are superior to conventional methods in recognition accuracy and speed.

• Journal of Institute of Control, Robotics and Systems
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• v.18 no.11
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• pp.1027-1033
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• 2012

Semantic-based information retrieval techniques understand the meanings of the concepts that users specify in their queries, but the traditional semantic matching methods based on the ontology tree have three weaknesses which may lead to many false matches, causing the falling precision. In order to improve the matching precision and the recall of the information retrieval, this paper proposes a multi-agent improved semantic similarity matching algorithm based on the ontology tree, which can avoid the considerable computation redundancies and mismatching during the entire matching process. The results of the experiments performed on our algorithm show improvements in precision and recall compared with the information retrieval techniques based on the traditional semantic similarity matching methods.

• Journal of the Korea Fashion and Costume Design Association
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• v.3 no.2
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• pp.107-119
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• 2001

Compared on dye, pigment is not colored to textiles, fixed by binders, so it has been used for less expensive textiles. However, the function of a binder hs been improved s organic chemical industry develops, and the flexibility and softness of textiles hs gotten better. Some of dye printing is being replace by pigment printing. Pigment printing skills illuminated and make colors represented cleariy. Since their durabillty is reasonably good and washing processes are not needed, further development of these printing skills are predictable. This study suggests color samples though theoretical researches and experiments on pigment printing that causes less pollution and en be colored on any type of textiles. Especially, over printing can be used in industrial fields because it saves processing and expense. For the improvement of pigment printing skills, more improved studies on binders are expected.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.569-570
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• 2009

An improvement of the test method is proposed to more accurately measure early-age autogenous shrinkage in concrete particularly within first 24 hours after casting. Experiments were conducted considering existing and improved method. In improved method, hydration temperature was artificially controlled to prevent thermal deformations. Test results indicate that the autogenous shrinkage calculated by existing approach is underestimated which might be due to the wrong assumption of considering the thermal dilation coefficient to be constant (equal to 10 ${\times}$ $10^{-6}/^{\circ}C$) at early-age. We recommend that the proposed method should be adopted to better assess precise value of autogenous shrinkage or an appropriate method of determining the time-evolution of thermal dilation coefficient be considered.

• Journal of information and communication convergence engineering
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• v.13 no.3
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• pp.215-219
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• 2015

Cells in a culture process transform with time and produce many overlapping cells in their vicinity. We are interested in a separation algorithm for images of overlapping cells taken using a fluorescence optical microscope system during a cell culture process. In this study, all cells are assumed to have an ellipse-like shape. For an ellipse fitting-based method, an improved least squares method is used by decomposing the design matrix into quadratic and linear parts for the separation of overlapping cells. Through various experiments, the improved least squares method (numerically stable direct least squares fitting [NSDLSF]) is compared with the conventional least squares method (direct least squares fitting [DLSF]). The results reveal that NSDLSF has a successful separation ratio with an average accuracy of 95% for two overlapping cells, an average accuracy of 91% for three overlapping cells, and about 82% accuracy for four overlapping cells.

• Journal of Power Electronics
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• v.17 no.1
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• pp.127-135
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• 2017

Recently the researches on modular multi-level converter (MMC) are being highlighted because high quality and efficient power transmission have become key issues in high voltage direct current (HVDC) systems. This paper proposes an improved pre-charging method for the sub-module (SM) capacitor of MMC-based HVDC systems, which operates in the nearest level control (NLC) modulation and does not need additional circuits or pulse width modulation (PWM) techniques. The feasibility of the proposed method was verified through computer simulations for a scaled 3-phase 10kVA MMC with 12 SMs per each arm. Hardware experiments with a scaled prototype have also been performed in the lab to confirm the simulation results.

• The Transactions of the Korea Information Processing Society
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• v.7 no.8
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• pp.2520-2527
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• 2000

An improved transition density propagation method for power estimation is proposed. The power estimation for the zero delay model is a proper criteria for the.lower boutldlIry for power consumption. A transition propagation method, including the zero delay model as a lower boundary for power stimation was studied. However, there were some redundancy factors in the process of transition density propagation. Hence this paper will explore the transition density propagation behavior to eliminate the redundancy factors and present theirriprQved estimation methodology for the signal transition density. The experiments show that the proposed method has comparably better estimation accuracy than the conventional methods.

• Proceedings of the IEEK Conference
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• 2002.07b
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• pp.900-903
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• 2002

This paper proposes the use of wavelet packet transform in a transform based video coding scheme, which is mainly used in low/very low bit-rate video coding schemes i.e. H.263 standard. In the experiments, the discrete cosine transform in the video coding scheme is replaced by the wavelet packet transform, and the improved performance in term of peak signal to noise ratio is measured and compared with the results obtained from the coding scheme implementing the ordinary wavelet transform. The experimental results show an impressive improvement obtained from the use of wavelet packet transform.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.15-18
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• 2003

This paper proposes a color matching 3D look-up table simplifying the complex color matching procedure between a monitor and a mobile display device. In order to perform color matching, it is necessary to process color of image in the device independent color space like CIEXYZ or CIELAB. We improved the S-curve model to have smaller characterization error than tolerance error. Also, as a result of the experiments, we concluded that the color matching look-up table with 64(4$\times$4$\times$4) is the smallest size allowing characterization error to be acceptable.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.14 no.5
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• pp.102-106
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• 2015

In this paper, we study the optimal design for improved rotation latch system performance. The factors affecting the Torque generated in the armature were chosen as design variables. Utilizing the vertical matrix, the orthogonal array table was created to predict the results through minimal analysis. To confirm the Torque generation amount, by utilizing the commercial electromagnetic analysis software MAXWELL, finite element analysis was performed. The approximation method and experimental design through the commercial PIDO tool PIAnO for optimal design and calculations were utilized to perform experiments using an optimization method with evolutionary algorithms. Using the approximation model, design factors were determined that can maximize the torque generated in the armature, and the simulation was performed.