• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.647-653
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• 2022

Data mining is a technique that explores knowledge such as relationships and patterns between data by exploring and analyzing data. Data that occurs in the real world includes a temporal attribute. Temporal data mining research to find useful knowledge from data with temporal properties can be effectively utilized for predictive judgment that can predict the future. In this paper, we propose an algorithm using time-unit grouping to classify the database into regular time period units and discover frequent pattern itemsets in time units. The proposed algorithm organizes the transaction and items included in the time unit into a matrix, and discovers frequent items in the time unit through grouping. In the experimental results for the performance evaluation, it was found that the execution time was 1.2 times that of the existing algorithm, but more than twice the frequent pattern itemsets were discovered.

• Proceedings of the Korean Information Science Society Conference
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• 2004.10b
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• pp.250-252
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• 2004

In this paper we apply several variations of independent component analysis( ICA) methods, such as spatial ICA (sICA), temporal ICA (tICA), and spatiotemporal ICA (stICA), to yeast cell cycle datasets, and compare their performance in finding components that result in gene clusters coherent with annotations and in extract ins meaningful temporal modes. It turns out that the results of tICA are superior to those of PCA, sICA, and stICA in terms of gene clustering and the temporal modes extracted by stICA highlights particular cellular processes.

• Journal of Information Display
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• v.11 no.2
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• pp.63-67
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• 2010

In these authors’ previous paper, it was shown that grey-level stability is one of the main drawbacks of the time-sequential stereoscopic 3D display. In the present study, it was demonstrated that a videoluminance meter can be used to rapidly and easily check the quality of such display. A dedicated pattern was applied to simultaneously check the effect of the grey level on the other eye and the effect of the temporal synchronization. The results were compared with those provided by a temporal model of the display, which was obtained by measuring its temporal behavior. The visual impact of the grey-level instabilities was precisely quantified, and they were found to be a major source of imperfections for the aforementioned display.

• Asia Marketing Journal
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• v.21 no.4
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• pp.1-24
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• 2020

The current research brings the spotlight onto customer Gapjil toward service employees. In an attempt to understand what brings Gapjil, the present article investigates the intertwined effects of perceived economic mobility (PEM), self-other referent priming (SORP), and temporal focus on Gapjil. Study 1 shows that PEM increases Gapjil among self-referent primed people, but not among other-referent primed people. Study 2 examining the role of temporal focus (present vs. future) reveals that the effect found in study 1 is replicated in the present focus, but the effect is reversed in the future focus. We explain this dynamic pattern of the 3-way interaction effect with a relative gratification and a motivation to attune the self to the perceived norm of the high class. We also discuss how to create a social atmosphere to lessen Gapjil in public and corporate communication strategies.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1260-1264
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• 2009

Precipitation time series is a mixture of complicate fluctuation and changes. The monthly precipitation data of 61 stations during 36 years (1973-2008) in Korea are comprehensively analyzed using the EOFs technique and CSEOFs technique respectively. The main motivation for employing this technique in the present study is to investigate the physical processes associated with the evolution of the precipitation from observation data. The twenty-five leading EOF modes account for 98.05% of the total monthly variance, and the first two modes account for 83.68% of total variation. The first mode exhibits traditional spatial pattern with annual cycle of corresponding PC time series and second mode shows strong North South gradient. In CSEOF analysis, the twenty-five leading CSEOF modes account for 98.58% of the total monthly variance, and the first two modes account for 78.69% of total variation, these first two patterns' spatial distribution show monthly spatial variation. The corresponding mode's PC time series reveals the annual cycle on a monthly time scale and long-term fluctuation and first mode's PC time series shows increasing linear trend which represents that spatial and temporal variability of first mode pattern has strengthened. Compared with the EOFs analysis, the CSEOFs analysis preferably exhibits the spatial distribution and temporal evolution characteristics and variability of Korean historical precipitation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.9
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• pp.3524-3531
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• 2010

In order to supply suitable services to users in ubiquitous computing environments, it is important to consider both location and time information which is related to all object and user's activity. To do this, in this paper, we design a spatial-temporal ontology considering user context and propose a system architecture for active mining user activity and service pattern. The proposed system is a framework for active mining user activity and service pattern by considering the relation between user context and object based on trigger system.

• Molecules and Cells
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• v.21 no.3
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• pp.436-442
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• 2006

Different proliferation of neuroblast 6-4 (NB6-4) in the thorax and abdomen produces segmental specific expression pattern of several neuroblast marker genes. NB6-4 is divided to form four medialmost cell body glia (MM-CBG) per segment in thorax and two MM-CBG per segment in abdomen. As homeotic genes determine the identities of embryonic segments along the A/P axis, we investigated if temporal and specific expression of homeotic genes affects MM-CBG patterns in thorax and abdomen. A Ubx loss-of-function mutation was found to hardly affect MM-CBG formation, whereas abd-A and Abd-B caused the transformation of abdominal MM-CBG to their thoracic counterparts. On the other hand, gain-of-function mutants of Ubx, abd-A and Abd-B genes reduced the number of thoracic MM-CBG, indicating that thoracic MM-CBG resembled abdominal MM-CBG. However, mutations in Polycomb group (PcG) genes, which are negative transregulators of homeotic genes, did not cause the thoracic to abdominal MM-CBG pattern transformation although the number of MM-CBG in a few percent of embryos were partially reduced or abnormally patterned. Our results indicate that temporal and spatial expression of the homeotic genes is important to determine segmental-specificity of NB6-4 daughter cells along the anterior-posterior (A/P) axis.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.3 no.3
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• pp.219-234
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• 2009

This paper presents a novel approach for extracting simultaneously human daily activity patterns and discovering the temporal relations of these activity patterns. It is necessary to resolve the services conflict and to satisfy a user who wants to use multiple services. To extract the simultaneous activity patterns, context has been collected from physical sensors and electronic devices. In addition, a context model is organized by the proposed incremental statistical method to determine conflicts and to infer user intentions through analyzing the daily human activity patterns. The context model is represented by the sets of the simultaneous activity patterns and the temporal relations between the sets. To evaluate the method, experiments are carried out on a test-bed called the Ubiquitous Smart Space. Furthermore, the user-intention simulator based on the simultaneous activity patterns and the temporal relations from the results of the inferred intention is demonstrated.

• Journal of the Korean Association of Geographic Information Studies
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• v.14 no.4
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• pp.182-193
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• 2011

In order to compare the spatio-temporal variation pattern of sea surface temperature (SST) in Korea's Southern areas of the sea according to a regional scale, this study has selected the winter and summer seasons for 31 years (1980~2010) in a period aspect and selected three areas of the sea such as the Western areas of the sea (region B) and Eastern areas of the sea (region C) around Jeju Island in addition to overall Southern areas of the sea (region A) in regional aspect. The regression analysis was applied to find out a temporal variation pattern of SST, and the weighted mean center (WMC) of SST as well as analysis of a standard deviational ellipse (SDE) was respectively applied. As a result of regression analysis of SST, it showed a rising long-term trend for all two seasons in three regions. However, though the average SST for 31 years was all similar in three regions in the summer season, the region C appeared more highly than region B in the winter season. The spatial variation pattern of SST for two seasons showed that it is respectively different from each other in three regions. The spatial variation pattern of SST appeared as E-W direction in region A, SE-NW direction in region B and SW-NE direction in region C. In addition, the relationship between the location of the WMC of SST and the average SST showed correlation in regions A and B in the winter season, whereas it appeared that there is no correlation in region C. Accordingly, it can be known that the regional scale should be considered in case of analysis of spatio-temporal variation patterns of SST.

• Journal of Positioning, Navigation, and Timing
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• v.4 no.2
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• pp.87-95
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• 2015

In this study, the temporal and spatial variation in precipitable water vapor (PWV) was analyzed for typhoon Ewiniar which had made landfall in the Korean peninsula in 2006. To make a contour map of PWV, zenith total delay (ZTD) was calculated using about 60 GPS permanent stations in Korea, and the pressure and temperature data of nearby AWS stations were interpolated and applied to the equation for calculating the PWV. While Typhoon Ewiniar was migrating north from the southern coast to the eastern coast of Korea, the PWV migrated showing a spatial distribution similar to that of rainfall. Also, the fluctuating pattern of the normalized PWV was analyzed, and the moving speed of the PWV was estimated using the delay time of the increase/decrease pattern in the eight-test stations. The result indicated that the moving speed of the PWV was about 35 km/h, which was similar to the average moving speed of the typhoon (38.9 km/h).