• Journal of Sensor Science and Technology
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• v.14 no.2
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• pp.109-115
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• 2005

Calibration is a prerequisite procedure for employing a camera as a 3D sensor in an automated machines like robots. As accurate sensing is possible only when the vision sensor is calibrated accurately, many different approaches and models have been proposed for increasing calibration accuracy. Particularly an important factor which greatly affects the calibration accuracy is the nonlinearity in the mapping between 3D world and corresponding 2D image. In this paper GMDH algorithm is used to learn the nonlinearity without physical modelling. The technique proposed can be effective in various situations where the levels of noises and characteristics of nonlinear distortion are different. In simulations and an experiment, the proposed technique showed good and reliable results.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.05a
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• pp.522-524
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• 2019

In spite of a rapid development in the quality of built-in mobile cameras, their some physical restrictions hinder them to achieve the satisfactory results of digital single lens reflex (DSLR) cameras. In this work we propose an end-to-end deep learning method to translate ordinary images by mobile cameras into DSLR-quality photos. The method is based on the framework of generative adversarial networks (GANs) with several improvements. First, we combined the U-Net with DenseNet and connected dense block (DB) in terms of U-Net. The Dense U-Net acts as the generator in our GAN model. Then, we improved the perceptual loss by using the VGG features and pixel-wise content, which could provide stronger supervision for contrast enhancement and texture recovery.

• Journal of Information Processing Systems
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• v.15 no.5
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• pp.1141-1155
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• 2019

Today, most approaches used in the recommendation system provide correct data prediction similar to the data that users need. The method that researchers are paying attention and apply as a model in the recommendation system is the communities' detection in the big social network. The outputted result of this approach is effective in improving the exactness. Therefore, in this paper, the personalized movie recommendation system that combines data mining for the k-clique method is proposed as the best exactness data to the users. The proposed approach was compared with the existing approaches like k-clique, collaborative filtering, and collaborative filtering using k-nearest neighbor. The outputted result guarantees that the proposed method gives significant exactness data compared to the existing approach. In the experiment, the MovieLens data were used as practice and test data.

• East Asian Economic Review
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• v.24 no.4
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• pp.349-388
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• 2020

The US-China trade war forced a reluctant semiconductor industry into someone else's fight, a very different position from its leading role in the 1980s trade conflict with Japan. This paper describes how the political economy of the global semiconductor industry has evolved since the 1980s. That includes both a shift in the business model behind how semiconductors go from conception to a finished product as well as the geographic reorientation toward Asia of demand and manufactured supply. It uses that lens to explain how, during the modern conflict with China, US policymakers turned to a legally complex set of export restrictions targeting the semiconductor supply chain in the attempt to safeguard critical infrastructure in the telecommunications sector. The potentially far-reaching tactics included weaponization of exports by relatively small but highly specialized American software service and equipment providers in order to constrain Huawei, a Fortune Global 500 company. It describes potential costs of such policies, some of their unintended consequences, and whether policymakers might push them further in the attempt to constrain other Chinese firms.

• Current Optics and Photonics
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• v.7 no.5
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• pp.537-544
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• 2023

Differential phase contrast (DPC) microscopy, a central quantitative phase imaging (QPI) technique in cell biology, facilitates label-free, real-time monitoring of intrinsic optical phase variations in biological samples. The existing DPC imaging theory, while important for QPI, is grounded in paraxial diffraction theory. However, this theory lacks accuracy when applied to high numerical aperture (NA) systems that are vital for high-resolution cellular studies. To tackle this limitation, we have, for the first time, formulated a nonparaxial DPC imaging equation with a transmission cross-coefficient (TCC) for high NA DPC microscopy. Our theoretical framework incorporates the apodization of the high NA objective lens, nonparaxial light propagation, and the angular distribution of source intensity or detector sensitivity. Thus, our TCC model deviates significantly from traditional paraxial TCCs, influenced by both NA and the angular variation of illumination or detection. Our nonparaxial imaging theory could enhance phase retrieval accuracy in QPI based on high NA DPC imaging.

• Asia pacific journal of information systems
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• v.33 no.3
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• pp.603-623
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• 2023

While prior work has conducted individuals' password security behavior, there is a relatively neglect to examine individuals' affect and feelings of password fatigue in password change context. Therefore, this study explicated individuals' affective response to the feelings of password fatigue by drawing on several theoretical lens. Survey data collected from 267 users were used to test the model using partial least square analysis. This study found that feelings of password fatigue positively affected the negative password fatigue-induced affect, and also both the feelings of password fatigue and the negative password fatigue-induced affect were negatively related to attitude toward changing passwords, which in turn, leads to the intention to change passwords. Furthermore, this study found that shadow work recognition negatively moderated the relationship between attitude and behavioral intention. This study could offer a new theoretical perspective to understand an individual's security behavior and provide empirical evidences for practitioners in charge of IT security in organizations.

• Asia pacific journal of information systems
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• v.26 no.3
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• pp.393-426
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• 2016

The qualities of the technological artifact of online shopping websites and the overall support delivered by the service provider through the website are generally agreed to be crucial elements in creating customer satisfaction and loyalty. However, a lack of consensus exists on how those qualities are related to each other, what they consist of, and how they can be conceptualized. Based on relevant literature and using a servicescape framework as a theoretical lens, we divide online shopping website qualities into information and system qualities and argue that both factors affect service quality. We conceptualize each of the three types of quality as a second-order formative construct comprising its most salient quality dimensions: information quality consisting of reliability, understandability, currency, and relevance; system quality consisting of usability, availability, and responsiveness; and service quality consisting of efficiency and fulfillment. Our model of how information, system, and service qualities are related to one another and to customer satisfaction and loyalty is then tested empirically with a data set of 570 online shopping customers. Our integrated model reconciles the seemingly contradictory conceptualizations of previous researchers and provides an effective way to create customer satisfaction and loyalty.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2007.05a
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• pp.848-851
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• 2007

Recently, as the demand of the information storage devices with large storage capacity such as BD(Blu-ray Disk) and HDTV(high-definition television) is increased, the optical storage devices are also required to have fast data transfer rate and large storage capacity. To satisfy these requirements, the actuator for optical disk drive should have high flexible mode frequencies for system stability. In this paper, we suggested a moving magnet type actuator having high flexible mode frequency. However, the moving magnet type actuator does not have sufficient driving sensitivities due to the weight of its moving part. To improve driving sensitivities, we designed the model with the closed electromagnetic circuit for tracking direction. In addition, driving sensitivities and flexible mode frequencies were improved by using DOE(Design of Experiments) for magnetic circuit and modifying the lens holder. Consequently, it is confirmed that the designed model is satisfied with the desired specifications.

• Journal of information and communication convergence engineering
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• v.15 no.1
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• pp.43-48
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• 2017

Movie ratings are crucial for recommendation engines that track the behavior of all users and utilize the information to suggest items the users might like. It is intuitively appealing that information about the viewing preferences in terms of movie genres is sufficient for predicting a genre of an unlabeled movie. In order to predict movie genres, we treat ratings as a feature vector, apply a Bernoulli event model to estimate the likelihood of a movie being assigned a certain genre, and evaluate the posterior probability of the genre of a given movie by using the Bayes rule. The goal of the proposed technique is to efficiently use movie ratings for the task of predicting movie genres. In our approach, we attempted to answer the question: "Given the set of users who watched a movie, is it possible to predict the genre of a movie on the basis of its ratings?" The simulation results with MovieLens 1M data demonstrated the efficiency and accuracy of the proposed technique, achieving an 83.8% prediction rate for exact prediction and 84.8% when including correlated genres.

• 유체기계공업학회:학술대회논문집
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• 2006.08a
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• pp.175-176
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• 2006

Electrowetting is prevailing for its various applicability on lap-on-a-chip, and MEMS devices, such as a pump, lens, micro-actuator in the micro-TAS technology. In the usual electrowetting, an AC power is preferred to DC practically. The AC electric field delays the contact angle-saturation, decreases the hysterisis, and is more stable in the view point of dielectric strength. But researches for AC electric field on electrowetting have not been reported very much yet. The different effect of AC on the electrowetting system, especially the effect of a frequency needs to be understood more concretely. In this work, the usual system for electrowetting, water droplet on the dielectric coated electrode (EWOD) is analyzed. Experimental study on the response of contact angles on input frequencies is performed. The simple circuit-model for EWOD system is considered to explain the experimental results. For more concrete understanding, the system is analyzed numerically, where simple AC-conduction model is used. Wetting tensions are analyzed under various input frequency to excavate the experimental results for the responses of the system on input frequencies.