• Proceedings of the IEEK Conference
• /
• 2007.07a
• /
• pp.293-294
• /
• 2007

The purpose of this study is prove the effectiveness of an energy subtraction image for the detection of pulmonary nodules and the effectiveness of multi-resolutional filter on an energy subtraction image to detect pulmonary nodules. Also we study influential factors to the accuracy of detection of pulmonary nodules from viewpoints of types of images, types of digital filters and types of evaluation methods. As one type of images, we select an energy subtraction image, which removes bones such as ribs from the conventional X-ray image by utilizing the difference of X-ray absorption ratios at different energy between bones and soft tissue. Here we select two evaluation methods and make clear the effectiveness of multi-resolutional filter on an energy subtraction image.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.14 no.5
• /
• pp.17-24
• /
• 2006

Anti-lock brake system(ABS) are designed to prevent wheel lock on all wheels of the vehicle by sensing wheel angular speed, processing the speed sensor signals in suitable digital electronic control circuits and comanding electrohydraulic actuators to control brake pressure. This study considers a control of ABS using wheel circumferential acceleration thresholds which avoids dangerous wheel locking due to excessive brake pressure during the vehicle braking and discusses the 3-channels, 3-sensors ABS system that employs "independent control" technique for the front wheels and "select low" technique for the rear wheels. The validities of the ABS such as vehicle stability, steerability and stopping distance during braking are assured through the vehicle tests on uniform asphalt straight roads.

• Communications for Statistical Applications and Methods
• /
• v.22 no.5
• /
• pp.507-518
• /
• 2015

It is not easy to select a linear mixed model since the main interest for model building could be different and the number of parameters in the model could not be clearly defined. In this paper, performance of conditional Akaike Information Criteria and its bias-corrected version are compared with marginal Bayesian and Akaike Information Criteria through a simulation study. The results from the simulation study indicate that bias-corrected conditional Akaike Information Criteria shows promising performance when candidate models exclude large models containing the true model, but bias-corrected one prefers over-parametrized models more intensively when a set of candidate models increases. Marginal Bayesian and Akaike Information Criteria also have some difficulty to select the true model when the design for random effects is nested.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.13 no.8
• /
• pp.3371-3380
• /
• 2012

This paper finds the selecting evaluation index of technical development supporting business, applied to determine its validity. Measuring the new evaluation index for selection against the existing select evaluation index, it shows which index has accurately estimated the ranking of the companies with good performance. Using the BSC and AHP method, this study developed the select evaluation index of technology development supporting business.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.22 no.49
• /
• pp.11-21
• /
• 1999

The purpose of this study is to present the method to select optimal size for the industrial products which are closely related to human's body size. For this purpose, human factors such as body characteristics, body features, and preference in product selection which needs to be considered in setting standards were analyzed. This analysis is to select optimal size to minimize losses caused by the difference of size between demand by the customers and supply from the manufacturers. Using loss function, repetitive calculation process algorithm by using bisearch method was applied in selecting the sizes of demand and supply which minimize the total expected losses. For cumulative normal distribution probability, IMSL routine DNORDF was used. In case study, comparison has been made between the result which was calculated using presented algorithm and the results calculated by the process currently used by KS and ISO by measuring aged women's body size in human factors side and sorting them through the factor analysis and cluster analysis for feature factor extraction. Thus, they can be used as a basis for establishing industrial product standards.

• Journal of Power Electronics
• /
• v.19 no.5
• /
• pp.1099-1107
• /
• 2019

A soft switching converter with wide voltage range operation is investigated in this paper. A series resonant converter is implemented to achieve a high circuit efficiency with soft switching characteristics on power switches and rectifier diodes. To improve the weakness of the narrow voltage range in LLC converters, an alternating current (ac) power switch is used on the primary side to select a half-bridge or full-bridge resonant circuit to implement 4:1 voltage range operation. On the secondary-side, another ac power switch is adopted to select a full-wave rectifier or voltage-doubler rectifier to achiever an additional 2:1 output voltage range. Therefore, the proposed resonant converter has the capacity for 8:1 (320V~40V) wide output voltage operation. A single-stage hybrid resonant converter is employed in the study circuit instead of a two-stage dc converter to achiever wide voltage range operation. As a result, the study converter has better converter efficiency. The theoretical analysis and circuit characteristics are verified by experiments with a prototype circuit.

• Journal of Korean Society on Water Environment
• /
• v.23 no.5
• /
• pp.591-599
• /
• 2007

The quality of water released from a stratified reservoir is dependent on various factors such as the location and shape of intake facility, structure of reservoir stratification, profile of water quality constituent, and withdrawal flux. Sometimes, selective withdrawal capabilities can provide the operational flexibility to meet the water quality demands both in-reservoir and downstream. The objective of this study was to evaluate the performance of a one-dimensional reservoir selective withdrawal model (SELECT) as a tool for supporting downstream water quality management for Daecheong and Imha reservoirs. The simulated water quality variables including water temperature, dissolved oxygen (DO), conductivity, turbidity were compared with the field data measured in tailwater. The model showed fairly satisfactory results and high reliability in simulating observations. The coefficients of determinant between simulated and observed turbidity values were 0.93 and 0.95 for Daecheong and Imha reservoirs, respectively. The outflow water quality was significantly influenced by water intake level under fully stratified condition, while the effect of intake amount was minor. In conclusion, the SELECT is simple but effective tool for supporting downstream water quality prediction and management for both reservoirs.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.10 no.5
• /
• pp.1060-1064
• /
• 2009

This paper proposes a fuzzy AHP based decision-making model to select a telecommunication company and the target of the proposed model is university students in the capital area. When customers select a telecommunication company, they have difficulty in decision-making because there are many competitive and complementary factors of telecommunication companies. To select a best telecommunication company, customers need to consider a number of different quantitative and qualitative factors such as fare, various services, additional function, etc. In this study, we suggest a fuzzy AHP based decision-making model to select a telecommunication company considering various quantitative and qualitative factors. Especially, fuzzy theory is applied to deal with the unclear or ambiguous problems, and a linear normalization model is developed to convert the value of quantitative factors to fuzzy number. A empirical example which is the target of the university students in the capital area shows the feasibility of the proposed model and it can help customers to make better decision-making for their benefits.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.14 no.1
• /
• pp.117-124
• /
• 2010

Different to other social infrastructures, bridge elements or bridges can be damaged or collapsed and this may cause death toll and severe social and economical damage, bridges should be managed to maintain a safety level. Diverse strengthening methods is developed to improve a deteriorated bridge performance up to original design level. But rational decision-making process and methodologies to select a optimum strengthening method are absence yet in Korea. This paper therefore derived items and proposed methodologies for quantity estimate considering uncertainty to select a optimum strengthening method among conceptually designed alternatives. And also, to demonstrate the applicability and verification of the proposed approach, it was applied to select the optimum strengthening method for the deteriorated T-shape concrete girder bridge. The model and the procedure can greatly contribute to the uncertainty-oriented alternative selection.

• Culinary science and hospitality research
• /
• v.22 no.3
• /
• pp.33-43
• /
• 2016

This study examined the factors that affect the relationship between consumption value, bakery select properties and satisfaction. A total of 320 questionnaires were distributed to consumers, of which 300 were deemed suitable for analysis after the removal of 20 unusable responses. In order to perform required statistical analyses in the study, the SPSS 18.0 Statistical Program was used for frequency analysis, factor analysis, reliability analysis, correlations, and regression analysis. The results of exploratory factor analysis showed that four factors regarding consumption value were extracted from all measurements with a KMO of 0.841 and a total cumulative variance of 72.937%, With regard to bakery select property, one factor was extracted with a total cumulative variance of 64.917% and a KMO score of 0.756. One factor for satisfaction was extracted that accounted for a total cumulative variance of 76.944% and a KMO score of 0.719. All factors were significant to 0.000 and the correlation between variables was significant. Thus, based on the results, the main research hypothesis that identifies the relationship between consumption value, bakery select property and satisfaction was partially adopted.