• Proceedings of the Korean Operations and Management Science Society Conference
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• 2002.05a
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• pp.93-97
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• 2002

In this paper, we propose personalized recommendation techniques based on multidimensional scaling (MDS) method for Business to Consumer Electronic Commerce. The multidimensional scaling method is traditionally used in marketing domain for analyzing customers' perceptional differences about brands and products. In this study, using purchase history data, customers in learning dataset are assigned to specific product categories, and after then using MDS a positioning map is generated to map product categories and alternative advertisements. The positioning map will be used to select personalized advertisement in real time situation. In this paper, we suggest the detail design of personalized recommendation method using MDS and compare with other approaches (random approach, collaborative filtering, and TOP3 approach)

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.5
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• pp.31-38
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• 2008

Recently the necessity of time history analyses is increasing for the seismic analyses of a structure, and the seismic design provisions of IBC2003, ASCE and KBC2005 require the use of a minimum of seven earthquake records for the time history analyses. Earthquake records for the time history analyses could be selected from the database of the field-measured earthquake records having similar site conditions with the designed site, or from simulated sites satisfying the design spectrum. However, in this study seven earthquake records were generated using 50 earthquake records, classified as records measured at the rock, in the database of the Pacific Earthquake Research Center (PEER). Seven earthquake records were first selected by the least squares fitting method comparing the scaling factored response spectra with the specified design spectrum, and a family of seven artificial time history earthquake records was ultimately generated by multiplying scaling factors, which were calculated by the least squares fitting method and the SRSS averaging method, to the corresponding selected earthquake records.

• Journal of Korean society of Dental Hygiene
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• v.3 no.1
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• pp.73-87
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• 2003

This study was performed on 17 female dental hygienists to find an appropriate method to reduce the hygienists' body discomfort while scaling, and provide a foundation to educate them how 10 posture during the process. To assess the arm abduction, elbow flexion, neck flexion, trunk flexion and trunk lateral bending through Video 2D(two dimensional motion) analysis and assessing the risk through the Action level of RULA(rapid upper limb assessment) checklist, an ergonomic analysis method. Correlation analyses on the posture angles and on body discomfort were performed. ANOVA analysis on scaling treatment position and the scaling treatment region of patients was also performed. The results are as following. 1. 20 analysis while scaling, arm abduction was $40{\sim}79.9^{\circ}$, elbow flexion $20{\sim}110^{\circ}$, neck flexion $50{\sim}100^{\circ}$, trunk flexion $60{\sim}80^{\circ}$, and trunk lateral bending $5{\sim}19.9^{\circ}$. 2. The Action level of RULA was 2. 3 resulted from scores 4 and 5 of group A which includes upper arm, lower ann, wrist, and scores 2 and 4 of group B which includes neck, trunk, legs. It means that the scaling treatment posture causes a high incidence rate of musculoskeletal that an additional investigation and improvement should be followed without hesitation. 3. There were significant differences among the maxilla right, maxilla anterior, maxilla left, mandible left, mandible anterior, and mandible right of a patient of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment. 4. There were significant differences among the time position of 8, 9, 10, 11, 12, 13 of the right and left upper arm, lower arm, neck, trunk, group A, group B, final RULA score while scaling treatment, 5. As for the body discomfort, neck, right shoulder, left shoulder, right back, right wrist etc. were listed on top. As a conclusion, performing the time position of 12 which shows low right and left final RULA scores is better than the time position of 8 and 10 which show high final RULA scores to reduce the body discomfort while scaling treatment.

• Journal of dental hygiene science
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• v.18 no.5
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• pp.319-326
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• 2018

Although scaling is the primary method for improving oral health, it is also associated with dental fear. The objective of this study was to empirically verify whether the use of gel anesthetic within the gingival sulcus during scaling relieves pain and improves other factors. A total of 128 patients scheduled to undergo scaling at a dental clinic of a general hospital located in the Gyeonggi Province, between July 2014 and July 2015, were enrolled in the study. The participants underwent scaling following the application of 20% benzocaine gel or placebo gel anesthetic within the gingival sulcus, and the data was collected using a questionnaire. There was a significant difference in the severity of pain, participant satisfaction, perceived sensitivity, overall discomfort, and fear of scaling between the two groups. The two groups were compared in terms of perceived need for gel anesthesia, willingness to pay for anesthesia costs, and willingness to receive scaling in the future. There were significant differences in all the three parameters depending on whether gel anesthesia was used or not. There were significant differences between the two groups in perceived sensitivity immediately after scaling and one day after scaling, with no difference seen one week after scaling. With regards to overall discomfort over time, there were significant differences between the two groups immediately after scaling. Based on these findings, we expect that application of gel anesthetic within the gingival sulcus during scaling will reduce pain, perceived sensitivity, overall discomfort, and fear of scaling with increased satisfaction.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.36 no.4
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• pp.252-258
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• 1987

Time periodic finite element solutions for sinusoidally excited electromagnetic field problems in moving media are presented. Solutions by the Galerkin method contain spurious oscillations when grid Peclet number is more than one. To suppress these oscillations an upwind finite element method using two different time periodic test functions is introduced. One is multiplied to second and first-order space derivative terma and the other to the time derivative term. Test functions are obtained from trial functions by adding or subtracting quadratic bias functions with appropriate scaling factors. Phase differences are considered between trial functions and bias functions. For simple interpretations of the phase differences, complex scaling factors are used. The proposed method is developed to give nodally exact solutions for uniform grid spacing in one dimensional problems. Based on the one dimensional results, a two dimensional upwinding scheme is also derived.

• Journal of the Korean Society for information Management
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• v.23 no.4 s.62
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• pp.215-231
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• 2006

Recently there are many bibliometric studies attempting to utilize Pathfinder networks(PFNets) for examining and analyzing the intellectual structure of a scholarly field. Pathfinder network scaling has many advantages over traditional multidimensional scaling, including its ability to represent local details as well as global intellectual structure. However there are some limitations in PFNets including very high time complexity. And Pathfinder network scaling cannot be combined with cluster analysis, which has been combined well with traditional multidimensional scaling method. In this paper, a new method named as Parallel Nearest Neighbor Clustering (PNNC) are proposed for complementing those weak points of PFNets. Comparing the clustering performance with traditional hierarchical agglomerative clustering methods shows that PNNC is not only a complement to PFNets but also a fast and powerful clustering method for organizing informations.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.3
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• pp.586-594
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• 2014

Maximizing the operating time by reducing the power consumption is important factor to operate sensor network under water networks. For efficient power consumption, dynamic voltage scaling method is available. This method operates low frequency when there is no workload. In case of abundant workload, high frequency operation completes hard work within short time, reducing power consumption. For this reason, complex cryptography should be computed in high frequency. In this paper, we apply dynamic voltage scaling method to cryptography and show performance evaluation. With this result, we can reduce power consumption for cryptography in under water communication.

• Journal of Institute of Convergence Technology
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• v.6 no.2
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• pp.9-13
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• 2016

Robot usually requires spline motion to move through multiple knots. In this paper, catmull-rom spline method is applied to the trajectory planning of industrial robot in task space. Centripetal catmull-rom is selected to avoid self-intersection and slow motion which can be occurred in uniform and chordal spline. The method to set two control points are proposed to satisfy velocity conditions of initial and final knots. To optimize robot motion, time scaling method is presented to minimize margin between real robot value and maximum value in velocity and acceleration. The simulation results show that the proposed methods are applied to trajectory planning and robot can follow the planned trajectory while robot motion does not exceed maximum value of velocity and acceleration.

• Horticultural Science & Technology
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• v.16 no.2
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• pp.242-243
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• 1998

This research was conducted to find the most effective and economical artificial propagation method of Lycoris squamigera among chipping, half-chipping, twin-scaling, coring, scooping and notching, in order to investigate the number of bulblets obtained from one bulb and the number of bulbs treated by a man in a day for artificial propagation. We got 42.2 bulblets from one bulb by twin-scaling, 23.2 bulblets by half-chipping, 18.2 bulblets by chipping, 14.3 bulblets by notching, 1 bulblet by coring and also 1 bulblet by scooping. Although we got the most bulblets by twin-scaling, it took the most time to treat the bulbs for artificial propagation (200 bulbs per day) and the bulblets formed were very small. But 400 bulbs were treated in a day by chipping and the bulblets formed were comparatively large. In addition, machines could be used for chipping, so chipping was considered to be the most effective and economical artificial propagation method.

• Earthquakes and Structures
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• v.16 no.1
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• pp.29-39
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• 2019

A three-step screening process is presented in this article for selection of consistent earthquake records in which number of suitable ground motions is quickly screened and reduced to a handful number. Records that remain at the end of this screening process considerably reduce the dispersion of structural responses. Then, an effective method is presented for spectral matching and modification of the selected records. Dispersion of structural responses is explored using different statistical measures for each scaling procedure. It is shown that the Uniform Design Method, presented in this study for scaling of earthquake records, results in most cases in the least dispersion measure.