• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.24 no.1
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• pp.137-147
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• 1994

A digital imaging system using Machintosh Ⅱ ci computer, high resolution Sony XC-77 CCD camera, Quickcapture Frame Grabber Board was evaluated for quantitative analysis of standardized periapical film with aluminum step wedge. The results were as follows: 1. Correlation between Al thickness and gray level was high-positively associated(r²=0.99, p<0.001). 2. Correlation between measured weight of experimental lesion and estimated relative lesion volume by digital subtracted radiography was also high-positively associated (r²=0.98, p<0.001). 3. As exposure time was increased, mean gray level was decreased(p<0.01) and slope of regression line between Al thickness and gray level was also decreased (p<0.01). And when the exposure time was shorter than 0.2 second, the value of r² was relatively low. On the basis of the above results, it is considered that this digital imaging system using a Macintosh Ⅱ ci computer & a high resolution CCD monochrome camera will be useful in evaluating digitized image from standardized periapical film quantitatively.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.394-396
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• 2000

This paper presents a new algorithm for the allocation of the reliability level of composite power system under deregulated electricity market. Under deregulated electricity market, it is required to establish a methodology that can evaluate supply cost and supply reliability of each demand to realize the available priority service reflected a preference of each customer. In this study, a concept of reliability differentiated electricity service as priority service to keep reliability of particular customer within a desirable level is proposed on HLII under deregulated competitive electricity market. The uncertainties of not only generators but also transmission lines are considered for the reliability evaluation in this study. The characteristics and effectiveness of this methodology are illustrated by the case studies on MRBTS and IEEE-RTS.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.391-393
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• 2000

This paper presents an new algorithm for the economic load dispatch considering the reliability level constraints of composite power system under deregulated electricity market. It is the traditional ELD problem that generation powers have been dispatched In order to minimize total fuel cost subjected to constraints which sum of powers generated must equal the received load and no violating lower and upper limit constraints on generation. Under deregulated electricity market, however, generation powers of a pool have to be reallocated newly in order to satisfy the reliability differentiated level required at a load point because of a reliability differentiated electricity service which is a part of the priority service. In this study, new economic load dispatch algorithm for reallocating the generation powers of a pool in order to satisfy the reliability differentiated level under deregulated competitive electricity market is proposed. The uncertainties of not only generators but also transmission lines are considered fer the reliability evaluation. The characteristics and effectiveness of this methodology are illustrated by the case studies on MRBTS and IEEE-RTS.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.403-410
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• 2009

In this paper, damping coefficients and effective masses of tuned liquid-type column dampers were quantitatively evaluated based on experimental results by using system identification technique. First, shaking table tests were performed for two types of tuned liquid-type column dampers. Then, the dynamic characteristics of dampers used in this study were experimentally grasped from harmonic wave excitation testing results of the dampers with various water level. Finally, damping ratios and effective masses of the dampers with varying water level were quantitatively evaluated from minimizing the errors between numerical and experimental results. It was confirmed from system identification results that damping ratio and effective mass are decreased as the water level of dampers is increased.

• The Journal of Korean Academic Society of Nursing Education
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• v.18 no.2
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• pp.284-292
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• 2012

Purpose: This study was to compare nursing performance by career levels in a career ladder system. Methods: This survey was conducted with 140 OR staff nurses. Ten unit managers evaluated their own staff with a performance evaluation tool composed of 51 items. Data were analyzed by frequency, t-test, one-way ANOVA, ${\chi}^2$-test, and ANCOVA. Results: In career level CN II, nursing performance showed differences by personal characteristics. However, there was no significant difference in level CN III. CN IIIs' nursing performance was significantly higher than CN IIs' in all domains. Nursing performance of CN III was significantly higher than CN IIs' in 5 to 10 years of clinical experience. Although there was no significant difference in other clinical experience groups, CN IIIs' scores were always higher than CN IIs' Conclusion: The results indicate that nursing performance improves with career ladder advancement. Organizations should encourage advancement to higher levels and eliminate obstacles.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.5
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• pp.1277-1283
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• 2010

Many e-learning systems adopts SCORM as an e-learning standard. E-learning systems evaluate and apply the learning difficulty in order to improve the studying efficiency. But, it is hard to change the learning difficulty and provide the customized learning contents during studying in SCORM. Because it is difficult to provide the customized contents to learners by changing the learners' level at runtime and to control optional learning. In this paper, we designed and implemented SCORM-based Contents Organization System on learners' level(SCOS) for complementing the SCORM's weakness. SCOS re-evaluates a learner's level whenever the learner's level is changed during learning, and provides customized contents on the learner's level.

• Structural Monitoring and Maintenance
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• v.5 no.1
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• pp.129-150
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• 2018

This paper presents the structural performance monitoring of an urban footbridge located in Hangzhou, China. The structural health monitoring (SHM) system is designed and implemented for the footbridge to monitor the structural responses of the footbridge and to ensure the structural safety during the period of operation. The monitoring data of stress and displacement measured by the fiber Bragg grating (FBG)-based sensors installed at the critical locations are used to analyze and assess the operation performance of the footbridge. A linear regression method is applied to separate the temperature effect from the stress monitoring data measured by the FBG-based strain sensors. In addition, the static vertical displacement of the footbridge measured by the FBG-based hydrostatic level gauges are presented and compared with the dynamic displacement remotely measured by a machine vision-based measurement system. Based on the examination of the monitored stress and displacement data, the structural safety evaluation is executed in combination with the defined condition index.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.1
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• pp.1-9
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• 2013

The current manufacturers have generated tremendous amount of digitized product data to efficiently share and exchange it with other stakeholders or various software systems for product development. The digitized product data is a valuable asset for manufacturers, and has a potential to support high level strategic decision makings needed at many stages in product development. However, the lack of studies on extraction of key performance indicators(KPIs) from product data management(PDM) databases has prohibited manufacturers to use the product data to support the decision makings. Therefore this paper examines a possibility of an architecture that supports KPIs for evaluation of product development performances, by applying multidimensional product data model and on-line analytic processing(OLAP) to operational databases of product data management. To validate the architecture, the paper provides a prototype product data management system and OLAP applications that implement the multidimensional product data model and analytic processing.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2011.05b
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• pp.111-114
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• 2011

Korea construction industry needs to secure its competitiveness in global construction markets and to urgently find out the proper approaches in consideration of the current situation of Korean construction enterprises and environmental changes in the international market. Korea has national plan to improve the competitive level of the construction industry. Expecially, Government is trying to build the global system in construction industry. But there are no the related national competitive date. Therefore, this paper suggested national competitive indicators and development direction in construction industry. And this research has presented the competitiveness analysis of construction industry with the consideration of condition of infrastructure, transparency and technological competitiveness.

• Journal of Korea Society of Digital Industry and Information Management
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• v.5 no.4
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• pp.19-26
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• 2009

Recently, the Main Memory DBMS is gradually being expanded by the appearance of a large capacity of a Main Memory System, the increase in business area where it requires a real time process, and the rise of the users' required level. The Main Memory DBMS, which is able to go through a large capacity data process of the disk-based DBMS and guarantees a high efficiency, has domestically developed and has been put to a practical use. This paper presents an examination of the applied technologies and the limits of Altibase system, which is Main Memory DBMS. Moreover, it evaluated and performed a comparative analysis on the performance level of the Main Memory DBMS and the disk-based DBMS based on the same application. After five trials of the experiment based on the operating application, it was confirmed that the performance level of the Main Memory DBMS is enhanced and is higher by 4.13 to 7.89 times than the disk-based DBMS.