• The Transactions of the Korea Information Processing Society
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• v.4 no.12
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• pp.2947-2959
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• 1997

Temporal data model is able to handle the time varying information, which is to add temporal attributes to conventional data model. The temporal data model is classified into three models depending upon supporting time dimension, that are the valid time model to support valid time, the transaction time model to support transaction model, and the bitemporal data model to support valid time and transaction time. Most temporal data models are designed to process the temporal data by extending the relational model. There are two types or temporal data model, which are the tuple timestamping and the attribute timestamping depending on time dimension. In this research, a concepts of temporal data model, the time dimension, types of thc data model, and a consideration for the data model design are discussed Also, temporal data models in terms of the time dimension are compared. And the aggregate function model of valid time model is proposed, and then logical analysis for its computing consts has been done.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.9 no.2
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• pp.45-51
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• 2000

This study proposes that analysis and evaluation method of time series ultrasonic signal using the chaotic feature extrac-tion for degradation extent. Features extracted from time series data using the chaotic time series signal analyze quantitatively material degradation extent. For this purpose analysis objective in this study if fractal dimension lyapunov exponent and strange attractor on hyperspace. The lyapunov exponent is a measure of the rate at which nearby trajectories in phase space diverge. Chaotic trajectories have at least one positive lyapunov exponent. The fractal dimension appears as a metric space such as the phase space trajectory of a dynamical syste, In experiment fractal(correlation) dimensions and lyapunov experiments showed values of mean 3.837-4.211 and 0.054-0.078 in case of degradation material The proposed chaotic feature extraction in this study can enhances ultrasonic pattern recognition results from degrada-tion signals.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.4
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• pp.83-97
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• 2005

We could confirm through this study that in the company which has secured its agility in an information technology dimension, a process dimension and an organization behavior dimension as a real time enterprise, various agility competences of that company are used more effectively for productivity Improvement, development on new products and customer satisfaction. Therefore, based on these determinant factors, it has been proved that an individually differentiated investment of technical and organizational resources for development and innovation of new products has contributed affirmatively to get a more efficient enterprise performance : and, in this point, it is verified again that the agility secured through a conversion toward the real time enterprise (RTE) is a more effective plan to increase the enterprise performance.

• Design & Manufacturing
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• v.2 no.1
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• pp.11-14
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• 2008

we can save a development cost and time as computer was used in tool and die design of car fields in die manufacture process. Dimension accuracy errors such as springback, springgo, overcrown and twist were reduced product accuracy and caused trouble to assembly each parts of car. In this paper, CADCEUS was used to modify and optimize results of deflection for a tail gate panel of car parts in order to reduce dimension accuracy errors by springback in sheet metal forming. As CADCEUS was used to apply for a tail gate panel, the time for quality to improve was reduced to 30%.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.6
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• pp.390-395
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• 2005

Sunspots are dark areas that grow and decay on the lowest level of the sun that is visible from the Earth. Shot-term predictions of solar activity are essential to help plan missions and to design satellites that will survive for their useful lifetimes. This paper presents a parallel-structure fuzzy system(PSFS) for prediction of sunspot number time series. The PSFS consists of a multiple number of component fuzzy systems connected in parallel. Each component fuzzy system in the PSFS predicts future data independently based on its past time series data with different embedding dimension and time delay. An embedding dimension determines the number of inputs of each component fuzzy system and a time delay decides the interval of inputs of the time series. According to the embedding dimension and the time delay, the component fuzzy system takes various input-output pairs. The PSFS determines the final predicted value as an average of all the outputs of the component fuzzy systems in order to reduce error accumulation effect.

• Journal of Dental Rehabilitation and Applied Science
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• v.18 no.3
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• pp.185-195
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• 2002

Purpose This article describes the historic and clinical aspects of the determination of the vertical dimension of occlusion and the synoptic procedure of the determination of the vertical dimension of occlusion in complete denture. The determining procedure of the susceptible vertical dimension of occlusion is one of the most important steps in construction of complete denture and prosthodontic treatment. It is considered essential for the improvement and the recovery of facial esthetics and stomatognathic functions. Results Several methods have been suggested for measurement of the vertical dimension of occlusion in the construction of complete denture and the prosthodontic rehabilitation. These range from pre-extraction records to the use of physiologic rest position, swallowing, phonetics, esthetics and facial proportion, etc. But, there is no universally accepted or completely accurate method. There seems to be no significant advantages of one technique other than those of cost, time and equipment requirements, and seems to be in controversial in determining the vertical dimension. Conclusion The vertical dimension of occlusion should be determined and reinspected carefully by dentist for a successful prosthesis with several methods. The more investigations are necessary for more objective and scientific techniques in determining the vertical dimension of occlusion.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.4
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• pp.301-312
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• 2022

In an extensive oral rehabilitation, determining a proper occlusal vertical dimension is a critical step and the starting point for successful treatment. Since changing the occlusal vertical dimension could be time-consuming, financially challenging, and physically demanding for both clinicians and patients, multi-faceted analysis and careful consideration are essential in the diagnosis and further treatment process. The purpose of this narrative review is to discuss the occlusal vertical dimension and its current issues, and to summarize previous methods of evaluating occlusal vertical dimension to propose clinical guidance for determining a viable occlusal vertical dimension for full-mouth rehabilitation.

• Imaging Science in Dentistry
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• v.32 no.2
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• pp.75-79
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• 2002

Purpose : To evaluate the effect of exposure time and image resolution on fractal dimension calculations for determining the optimal range of these two variances. Materials and Methods : Thirty-one radiographs of the mandibular angle area of sixteen human dry mandibles were taken at different exposure times (0.01, 0.08, 0.16, 0.25, 0.40, 0.64, and 0.80 s). Each radiograph was digitized at 1200 dpi, 8 bit, 256 gray level using a film scanner. We selected an Region of Interest (ROI) that corresponded to the same region as in each radiograph, but the resolution of ROI was degraded to 1000, 800, 600, 500, 400, 300, 200, and 100 dpi. The fractal dimension was calculated by using the tile-counting method for each image, and the calculated values were then compared statistically. Results: As the exposure time and the image resolution increased, the mean value of the fractal dimension decreased, except the case where exposure time was set at 0.01 seconds (α = 0.05). The exposure time and image resolution affected the fractal dimension by interaction (p<0.001). When the exposure time was set to either 0.64 seconds or 0.80 seconds, the resulting fractal dimensions were lower, irrespective of image resolution, than at shorter exposure times (α = 0.05). The optimal range for exposure time and resolution was determined to be 0.08- 0.40 seconds and from 400-1000 dpi, respectively. Conclusion : Adequate exposure time and image resolution is essential for acquiring the fractal dimension using tile-counting method for evaluation of the mandible.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.282-282
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• 2000

The analysis of the radiation effect on matter has been performed using stochastic methods. Recently, It was discovered that the detector pulses of radiation can be analysed using deterministic method that utilizes the chaotic behaviour with an attractor found in a noise region. We acquired a time series for pulse tram of Am-241 using scintillation detector and reconstructed a phase space, then performed new analysis for the radiation detection signal by applying embedding theory, Lyapunov exponent, correlation dimension, autocorrelation dimension, and power spectrum.

• The Journal of Asian Finance, Economics and Business
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• v.6 no.1
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• pp.177-185
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• 2019

Service quality is still a new concept to those who works in shipping lines services since it has not been identified as a mandatory factor to increase competitiveness. Most carriers are currently offering services at the same level of price, transit time, equipment, etc. Thus offering a high quality service is the best way for a carrier to differentiate itself from its competitors in the market. The research aims to conduct an assessment on service quality at Wan Hai Lines (WHL) outbound services based on the SERVQUAL model, form of dimension-by-dimension analysis. This study was based on a survey of 135 people. The outcome is the service quality of WHL outbound services can be identified by three dimension(s): Empathy and Responsiveness, Assurance, and Reliability. It would help management to have an overall picture about the current service quality, and to find solutions to improve service quality following the recommendations. WHL managers need to recognize that "Reliability" has the strongest influence on customers' expectations, then come "Empathy and Responsiveness" and "Assurance". Therefore, board of managers should spend time looking carefully at each of the three dimensions, especially for the biggest gap between perceptions and expectations of three dimensions as well. Then the recommendations were raised.