• Journal of Electrical Engineering and Technology
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• v.9 no.1
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• pp.27-36
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• 2014

This paper presents an adaptive wide-area damping controller (WADC) based on generalized predictive control (GPC) and model identification for damping the inter-area low frequency oscillations in large-scale inter-connected power system. A recursive least-squares algorithm (RLSA) with a varying forgetting factor is applied to identify online the reduced-order linearlized model which contains dominant inter-area low frequency oscillations. Based on this linearlized model, the generalized predictive control scheme considering control output constraints is employed to obtain the optimal control signal in each sampling interval. Case studies are undertaken on a two-area four-machine power system and the New England 10-machine 39-bus power system, respectively. Simulation results show that the proposed adaptive WADC not only can damp the inter-area oscillations effectively under a wide range of operation conditions and different disturbances, but also has better robustness against to the time delay existing in the remote signals. The comparison studies with the conventional lead-lag WADC are also provided.

• Journal of Digital Convergence
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• v.9 no.2
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• pp.65-77
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• 2011

The current study investigated how interpersonal trust is developed in online communities, where most of individual identities are unknown or doubtful. To better understand and theorize the underlying mechanism, a survey was conducted integrating the literature on computer-mediated communication (CMC) and extending previous research on social identify model. The findings confirmed that integrity, benevolence, and openness are essential components in the concept of trustworthiness, which is predicted by social identification and persistency of communication activities in the virtual community.

• Journal of Ecology and Environment
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• v.46 no.2
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• pp.126-135
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• 2022

Background: Pollinators are important ecological elements due to their role in the maintenance of ecosystem health, wild plant reproduction, crop production and food security. The pollinator-plant interaction supports the preservation of plant and animal populations and it also improves the yield in pollination dependent crops. Having knowledge about the plant-pollinator interaction is necessary for development of pesticide risk assessment of pollinators and conservation of endangering species. Results: Traditional methods to discover the relatedness of insects and plants are based on tracing the visiting pollinators by field observations as well as palynology. These methods are time-consuming and needs expert taxonomists to identify different groups of pollinators such as insects or identify flowering plants through palynology. With pace of technology, using molecular methods become popular in identification and classification of organisms. DNA metabarcoding, which is the combination of DNA barcoding and high throughput sequencing, can be applied as an alternative method in identification of mixed origin environmental samples such as pollen loads attached to the body of insects and has been used in DNA-based discovery of plant-pollinator relationship. Conclusions: DNA metabarcoding is practical for plant-pollinator studies, however, lack of reference sequence in online databases, taxonomic resolution, universality of primers are the most crucial limitations. Using multiple molecular markers is preferable due to the limitations of developed universal primers, which improves taxa richness and taxonomic resolution of the studied community.

• Smart Structures and Systems
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• v.33 no.4
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• pp.263-279
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• 2024

With the increasing diversity of internet media, available video data have become more convenient and abundant. Related video data-based research has advanced rapidly in recent years owing to advantages such as noncontact, low-cost data acquisition, high spatial resolution, and simultaneity. Additionally, structural nonlinearity extraction has attracted increasing attention as a tool for damage evaluation. This review paper aims to summarize the research experience with the recent developments and applications of video data-based technology for structural nonlinearity extraction and damage evaluation. The most regularly used object detection images and video databases are first summarized, followed by suggestions for obtaining video data on structural nonlinear damage events. Technologies for linear and nonlinear system identification based on video data are then discussed. In addition, common nonlinear damage types in disaster events and prevalent processing algorithms are reviewed in the section on structural damage evaluation using video data uploaded on online platform. Finally, a discussion regarding some potential research directions is proposed to address the weaknesses of the current nonlinear extraction technology based on video data, such as the use of uni-dimensional time-series data as leverage to further achieve nonlinear extraction and the difficulty of real-time detection, including the fields of nonlinear extraction for spatial data, real-time detection, and visualization.

• Journal of Pharmacopuncture
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• v.27 no.3
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• pp.199-210
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• 2024

Objectives: Few studies have examined the impact of healthy sleep among general workers on individuals and society. Therefore, the status and risk factors of sleep disturbances among general workers were investigated. In addition, this study assessed the degree to which cold and heat symptoms are associated with sleep disturbances. Methods: A nationwide cross-sectional study was conducted through an online questionnaire focused on sleep disturbances of the general public in 2021. The degree of cold-heat pattern Identification (CHPI) of the general public was also surveyed. Descriptive statistics and multivariate logistic regression were used to derive the study results. Results: Data from 2,822 workers out of 3,900 valid questionnaires were analyzed. Approximately half of the respondents (49.93%) had sleep disturbances. Among the types of work, self-employed, two-shift work, and working more than 53 hours were associated with sleep disturbances. Sleep disturbances were positively associated with six cold and heat symptoms: three cold symptoms (coldness of the abdomen, coldness of body, and pale face) and three heat symptoms (body feverishness, feverishness of the limbs, and drinking cold water). Conclusion: Customized policies to maintain healthy work are needed for self-employed work, two-shift work, and long working hours, which are risk factors for workers' sleep disturbances. In addition, medical personnel can effectively diagnose and treat sleep disturbances considering the worker's cold and heat symptoms.

• Journal of Korean Library and Information Science Society
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• v.54 no.1
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• pp.191-220
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• 2023

This research attempts to identify how members of an online community collaboratively engaged with particular social information behaviors and accomplished a defined collective action. While responding to the Sewol Ferry tragedy, MissyUSA members quickly communicated and mobilized a collective action, a full-page ad campaign in The New York Times. As a follow up study, this secondary analysis quantitatively analyzes the primary data from a previous study to explore potential relationships or underlying factors among the various identified information behaviors. In this study, nineteen of the previously identified information behaviors were analyzed using exploratory factor analysis, yielding a total of eight factors. The two major factors of shared representation/collective identification and mobilizing resources verified the findings of the previous study and are in line with the findings typical of political science. The three factors of collaborative decision-making, reaction to tension, and brainstorming were factors that maximized communication and mobilization online, without any face-to-face communication or physical organization. Three emergent factors of outburst of dissent, boycott, and planning explained how members used negative emotions of anger, referential information for boycott, and incubated next collective actions. Through exploratory factor analysis, this study verifies and expands on the findings of the previous study by identifying several emergent factors that relate to the collaborative information behaviors of an online community engaged in a collective action.

• Journal of Korea Game Society
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• v.13 no.6
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• pp.53-64
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• 2013

This study investigated how parents' parenting attitude and youth's subjective class identification influence on game addiction. Total 177 youths from 16 to 24 participated an online survey. According to the results, parents' excessive expectation and youths' high level of self-control were associated with low level of game addiction. We divided a total into two groups; low subjective class identification group vs. high subjective class identification group based on the subjective class identification(SCI) scores. In low SCI group, excessive expectation and high level of self-control were associated with low level of game addiction. On the contrary, in high SCI group, only interference was associated with low level of game addiction. Parents' certain parenting attitude variables and individuals' level of SCI is strongly related to addictive use of game media and other various type of new media.

• Smart Structures and Systems
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• v.15 no.4
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• pp.1121-1137
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• 2015

This study presents probabilistic-based damage identification technique for highlighting damage in metallic structures. This technique utilizes distributed piezoelectric transducers to generate and monitor the ultrasonic Lamb wave with narrowband frequency. Diagnostic signals were used to define the scatter signals of different paths. The energy of scatter signals till different times were calculated by taking root mean square of the scatter signals. For each pair of parallel paths an error function based on the energy of scatter signals is introduced. The resultant error function then is used to estimate the probability of the presence of damage in the monitoring area. The presented method with an autofocusing feature is applied to aluminum plates for method verification. The results identified using both simulation and experimental Lamb wave signals at different central frequencies agreed well with the actual situations, demonstrating the potential of the presented algorithm for identification of damage in metallic structures. An obvious merit of the presented technique is that in addition to damages located inside the region between transducers; those who are outside this region can also be monitored without any interpretation of signals. This novelty qualifies this method for online structural health monitoring.

• Journal of Intelligence and Information Systems
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• v.12 no.3
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• pp.95-110
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• 2006

To enhance the rule-based reasoning capability of Semantic Web, the XRML (eXtensible Rule Markup Language) approach embraces the meta-information necessary for the extraction of explicit rules from Web pages and its maintenance. To effectuate the automatic identification of rules from unstructured texts, this research develops a framework of using rule ontology. The ontology can be acquired from a similar site first, and then can be used for multiple sites in the same domain. The procedure of ontology-based rule identification is regarded as a graph search problem with incomplete nodes, and an A* algorithm is devised to solve the problem. The procedure is demonstrated with the domain of shipping rates and return policy comparison portal, which needs rule based reasoning capability to answer the customer's inquiries. An example ontology is created from Amazon.com, and is applied to the many online retailers in the same domain. The experimental result shows a high performance of this approach.

• Journal of the Korean Institute of Intelligent Systems
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• v.14 no.4
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• pp.506-511
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• 2004

Biometrics is getting more and more attention in recent years for security and other concerns. So far, only fingerprint recognition has seen limited success for on-line security check, since other biometrics verification and identification systems require more complicated and expensive acquisition interfaces and recognition processes. Hand-Geometry has been used for biometric verification and identification because of its acquisition convenience and good performance for verification and identification performance. Hence, it can be a good candidate for online checks. Therefore, this paper proposes a Hand-Geometry recognition system based on geometrical features of hand. From anatomical point of view, human hand can be characterized by its length, width, thickness, geometrical composition, shapes of the palm, and shape and geometry of the fingers. This paper proposes thirty relevant features for a Hand-Geometry recognition system. However, during experimentation, it was discovered that length measured from the tip of the finger was not a reliable feature. Hence, we propose a new technique based on Genetic Algorithm for extraction of the center of nail bottom, in order to use it for the length feature.