• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.35 no.4
• /
• pp.311-321
• /
• 2022

The report reviews recent research efforts in demonstrating a computing system whose operation principle mimics the dynamics of biological neurons. The temporal variation of the membrane potential of neurons is one of the key features that contribute to the information processing in the brain. We first summarize the neuron models that explain the experimentally observed change in the membrane potential. The function of ion channels is briefly introduced to understand such change from the molecular viewpoint. Dedicated circuits that can simulate the neuronal dynamics have been developed to reproduce the charging and discharging dynamics of neurons depending on the input ionic current from presynaptic neurons. Key elements include volatile memristors that can undergo volatile resistance switching depending on the voltage bias. This behavior called the threshold switching has been utilized to reproduce the spikes observed in the biological neurons. Various types of threshold switch have been applied in a different configuration in the hardware demonstration of neurons. Recent studies revealed that the memristor-based circuits could provide energy and space efficient options for the demonstration of neurons using the innate physical properties of materials compared to the options demonstrated with the conventional complementary metal-oxide-semiconductors (CMOS).

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.1
• /
• pp.409-422
• /
• 2022

The purpose of this paper is to explore how the country-of-origin image mediates the effect of national stereotypes along two dimensions of perceived competence and warmth, on consumers' consumption behaviors, especially in today's environment, the capricious COVID-19 and the deepening and expanding "The Belt and Road" initiative. Research design, data, and methodology: After collecting 1500 primary data from twelve countries along the 21^st - Century Maritime Silk Road, this paper conducts ANOVA and SEM in SPSS25.0 and AMOS 24.0 separately to analyze measurements, structural models, and hypotheses via using 1277 final samples. The mediation results illustrate the asymmetric dominance of the two dimensions of national stereotypes, indicating that the country-of-origin image shows the complementary mediation in the effect of perceived competence on purchase intention; whereas, the country-of-origin image holds the indirect-only mediation in the impact of perceived warmth on purchase intention. The results of the moderation show that the effect of country-of-origin image on purchase intention is more significant for consumers who perceive COVID-19 in China to be of lesser severity than those who believe it to be of higher severity. Based on the paper's results, some implications for practice and theory are highlighted.

• The Bulletin of The Korean Astronomical Society
• /
• v.44 no.2
• /
• pp.42.3-42.3
• /
• 2019

We translate Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) ultraviolet (UV) multi-channel images into another UV single-channel image using a deep learning algorithm based on conditional generative adversarial networks (cGANs). The base input channel, which has the highest correlation coefficient (CC) between UV channels of AIA, is 193 Å. To complement this channel, we choose two channels, 1600 and 304 Å, which represent upper photosphere and chromosphere, respectively. Input channels for three models are single (193 Å), dual (193+1600 Å), and triple (193+1600+304 Å), respectively. Quantitative comparisons are made for test data sets. Main results from this study are as follows. First, the single model successfully produce other coronal channel images but less successful for chromospheric channel (304 Å) and much less successful for two photospheric channels (1600 and 1700 Å). Second, the dual model shows a noticeable improvement of the CC between the model outputs and Ground truths for 1700 Å. Third, the triple model can generate all other channel images with relatively high CCs larger than 0.89. Our results show a possibility that if three channels from photosphere, chromosphere, and corona are selected, other multi-channel images could be generated by deep learning. We expect that this investigation will be a complementary tool to choose a few UV channels for future solar small and/or deep space missions.

• Asia pacific journal of information systems
• /
• v.33 no.3
• /
• pp.737-767
• /
• 2023

With the availability of big customer data and advances in machine learning techniques, the prediction of customer behavior at the session-level has attracted considerable attention from marketing practitioners and scholars. This study aims to predict customer purchase conversion at the session-level by employing customer profile, transaction, and clickstream data. For this purpose, we develop a multimodal deep learning fusion model with dynamic and static features (i.e., DS-fusion). Specifically, we base page views within focal visist and recency, frequency, monetary value, and clumpiness (RFMC) for dynamic and static features, respectively, to comprehensively capture customer characteristics for buying behaviors. Our model with deep learning architectures combines these features for conversion prediction. We validate the proposed model using real-world e-commerce data. The experimental results reveal that our model outperforms unimodal classifiers with each feature and the classical machine learning models with dynamic and static features, including random forest and logistic regression. In this regard, this study sheds light on the promise of the machine learning approach with the complementary method for different modalities in predicting customer behaviors.

• Advances in concrete construction
• /
• v.16 no.4
• /
• pp.217-230
• /
• 2023

Methods for designing the post-tensioned anchorage zones at ultimate limit state has been specified in current design codes based on strut-and-tie models (STM). However, it is still not clear how to estimate the serviceability behavior of the anchorage zones. The serviceability is just indirectly taken into account by means of the reasonable reinforcement detailing. To address this issue, this paper is devoted to developing a modified strut-and-tie model (MSTM) to predict the behavior of concentric anchorage zones throughout the loading process. The principle of stationary complementary energy is introduced into STM at each load step to satisfy the compatibility condition and generate the unique MSTM. The structural behavior of anchorage zones can be achieved based on MSTM from loading to failure. Simplified formulas have been proposed to estimate the first cracking load, bearing capacity and maximum crack width with the consideration of the details of reinforcement bursting bars. The proposed model provides a definite method to control the bursting crack width in concentric anchorage zones. Four specimens with different bearing plate ratios have been designed and tested to validate the proposed method.

• Journal of Sensor Science and Technology
• /
• v.33 no.3
• /
• pp.139-146
• /
• 2024

Surface-enhanced Raman scattering (SERS) enables the detection of various types of π-conjugated biological and chemical molecules owing to its exceptional sensitivity in obtaining unique spectra, offering nondestructive classification capabilities for target analytes. Herein, we demonstrate an innovative strategy that provides significant machine learning (ML)-enabled predictive SERS platforms through surface-engineered graphene via complementary hybridization with Au nanoparticles (NPs). The hybridized Au NPs/graphene SERS platforms showed exceptional sensitivity (10^-7 M) due to the collaborative strong correlation between the localized electromagnetic effect and the enhanced chemical bonding reactivity. The chemical and physical properties of the demonstrated SERS platform were systematically investigated using microscopy and spectroscopic analysis. Furthermore, an innovative strategy employing ML is proposed to predict various analytes based on a featured Raman spectral database. Using a customized data-preprocessing algorithm, the feature data for ML were extracted from the Raman peak characteristic information, such as intensity, position, and width, from the SERS spectrum data. Additionally, sophisticated evaluations of various types of ML classification models were conducted using k-fold cross-validation (k = 5), showing 99% prediction accuracy.

• International Journal of Stem Cells
• /
• v.17 no.2
• /
• pp.120-129
• /
• 2024

Recent amendments to regulatory frameworks have placed a greater emphasis on the utilization of in vitro testing platforms for preclinical drug evaluations and toxicity assessments. This requires advanced tissue models capable of accurately replicating liver functions for drug efficacy and toxicity predictions. Liver organoids, derived from human cell sources, offer promise as a reliable platform for drug evaluation. However, there is a lack of standardized quality evaluation methods, which hinders their regulatory acceptance. This paper proposes comprehensive quality standards tailored for liver organoids, addressing cell source validation, organoid generation, and functional assessment. These guidelines aim to enhance reproducibility and accuracy in toxicity testing, thereby accelerating the adoption of organoids as a reliable alternative or complementary tool to animal testing in drug development. The quality standards include criteria for size, cellular composition, gene expression, and functional assays, thus ensuring a robust hepatotoxicity testing platform.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.22 no.5
• /
• pp.325-333
• /
• 2021

With the rapidly changing era of the fourth industrial revolution, the utilization of IT technology is increasing. In addition, the demand for security authentication is increasing as shared services or IoT technologies are being developed as new business models. Security authentication is becoming increasingly important for all intelligent devices such as self-driving cars. However, most location-based security authentication technologies are being developed mainly with technologies that utilize server proximity or satellite location tracking, which limits the scope of their physical use. Location-based security authentication technology has recently been developed as a complementary replacement technology. In this study, we introduce location-based security authentication technology using cell broadcasting technology, which has a wider range of applications and is more convenient and business-friendly than existing location-based security authentication technologies. We also introduced application cases and business models related to this. In addition to the current status of technology development, we analyzed current changes in business models being employed. Based on our analysis results, this study draws the implication that technology diversification is necessary to improve the performance of innovative technologies. It is meaningful that it has found and studied advanced technologies other than existing location authentication methods and systems.

• Journal of the Korean Geographical Society
• /
• v.47 no.1
• /
• pp.140-157
• /
• 2012

Most of global citizens in the globalization era want to live peacefully in the symbiotic relationship among each region or locality with its identity. From this perspective, the new regionalist models of development such as new industrial districts, industrial clusters, regional innovation systems, and global city-regions isn't helpful to most of regions because they were developed to increase the global competitiveness of industrial region from a few advanced industrial areas. This study attempts to develop 'regional differential development' as an alternative regional development theory. This theory puts emphasis on the truth that the difference or differential industry between regions in the real world connotes two essential values of development like the symbiosis of global citizens and the regional identity. Regional differential development seeks the development of regional differential industry on the basis of geographical elements with differential advantage, and hence it reviews significantly geographical elements including location, natural environment(landform, soil, climate, etc.), natural resources, population, transportation, culture, and landscape which appear substantially differently among regions. And to realize regional differential development successfully, it is crucial that actors(government, company, related institutions, and regional residents) actively participate and play each complementary role in the relationship of cooperation and conflict. Further study needs to secure the universal validity of this theory through many empirical studies.

• The Journal of Society for e-Business Studies
• /
• v.27 no.1
• /
• pp.43-62
• /
• 2022

This paper is a study to analyze when ISV(independent software company) has more active participation in the platform ecosystem. According to previous studies, companies are active in technological innovation when they can appropriate the outcome of innovation and when they have complementary assets (marketing, manufacturing capabilities, etc.) that can convert the innovation into value. The effect of these two conditions to join platform ecosystem is investigated. The duplication between the ISV's product portfolio and platform service is also included as an independent variable. The two sample groups are composed of independent SW companies that signed a partner agreement with platform companies and non-participating companies in the platform. As a result of empirical study, it is found that the patent rights do not affect participation in the platform. The ISVs might have believed that the benefits from cooperation with platform companies are greater than the risks of exposure to innovative technologies and unique Biz models. On the other hand, downstream's capability and the duplication of product portfolio affect participation in the platform. If ISVs have the downstream capability to transform cooperation into value creation, ISVs are actively participating in the platform. In addition, cooperation is active when the product portfolio is complementary to platform service rather than competition. This study is the empirical study of open innovation between Korean independent software companies and digital platform companies. There are similar prior studies abroad, but there are no similar studies in Korea. It is meaningful in that the determinants of platform ecosystem participation were investigated through empirical analysis by composing a sample group of companies participating in the platform ecosystem and companies not participating in the platform ecosystem.