• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1439-1449
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• 2007

The challenging aspect of CWR (continuous welded rail) is the additional axial forces in rails, mainly due to the thermal expansion of steel plate girder and rail itself. It has been found that these axial forces are proportional to girder length, total bridge length and bolt tightening forces. Also these forces are dependent to girder support conditions, types of bearings and their arrangements. With CWR, the authors' previous studies show that performance improvements like noise reduce, fatigue resistances and bearing durability increment can be expected. In addition to these effects, secondary effects due to the semi integral behavior between rail and bridge girder also can be expected. Special bearings which can reduce the absolute maximum axial forces have been developed, and applied to real 100m span bridge. The performance improvements were verified through site measurements and numerical analysis. The purpose of this study is to confirm the expected performance improvement aspects of steel plate girder bridges with CWR. To verify these aspects, girder stiffness changes, rail axial force changes, girder displacements and noise level were thoroughly measured and compared.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.113.4-113
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• 2001

A 24 channel L1 C/A-code GPS attitude-finding receiver is designed and implemented. The performance of developed receiver is evaluated under the various environments. The results show that the performances from land and maritime test are almost same in the calm lake. And it follows the expected performance derived from an analysis. It is expected that the developed receiver can be used in not only maritime applications but also land and air applications where the heading is required.

• Journal of Electrical Engineering and Technology
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• v.12 no.4
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• pp.1376-1385
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• 2017

This paper proposes a method for estimating the expected frequency of voltage swells caused by asymmetrical faults in a power system. Although voltage swell is less common than voltage sag, repeated swells can have severe destructive impact on sensitive equipment. It is essential to understand system performance related to voltage swells for finding optimal countermeasures. An expected swell frequency at a sensitive load terminal can be estimated based on the concept of an area of vulnerability (AOV) and long-term system fault data. This paper describes an effective method for calculating an AOV to voltage swells. Interval estimation for an expected swell frequency is also presented for effective understanding of system performance. The proposed method provides long-term performance evaluation of the frequency and degree of voltage swell occurrences.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.279-286
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• 2013

This paper introduces a new method for identification of building energy performance problems. The presented method is based on automated analysis and visualization of deviations between actual and expected energy performance of the building using EPAR (Energy Performance Augmented Reality) models. For generating EPAR models, during building inspections, energy auditors collect a large number of digital and thermal imagery using a consumer-level single thermal camera that has a built-in digital lens. Based on a pipeline of image-based 3D reconstruction algorithms built on GPU and multi-core CPU architecture, 3D geometrical and thermal point cloud models of the building under inspection are automatically generated and integrated. Then, the resulting actual 3D spatio-thermal model and the expected energy performance model simulated using computational fluid dynamics (CFD) analysis are superimposed within an augmented reality environment. Based on the resulting EPAR models which jointly visualize the actual and expected energy performance of the building under inspection, two new algorithms are introduced for quick and reliable identification of potential performance problems: 1) 3D thermal mesh modeling using k-d trees and nearest neighbor searching to automate calculation of temperature deviations; and 2) automated visualization of performance deviations using a metaphor based on traffic light colors. The proposed EPAR v2.0 modeling method is validated on several interior locations of a residential building and an instructional facility. Our empirical observations show that the automated energy performance analysis using EPAR models enables performance deviations to be rapidly and accurately identified. The visualization of performance deviations in 3D enables auditors to easily identify potential building performance problems. Rather than manually analyzing thermal imagery, auditors can focus on other important tasks such as evaluating possible remedial alternatives.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.59 no.4
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• pp.450-455
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• 2010

The performance modeling of a $25{\mu}m$ pitch VGA ${\mu}$-bolometer with the self-aligned thermal resistor structure is carried out. The self-aligned thermal resistor can be utilized for the maximizing the thermal resistance and the fill factor of a bolometer, so the performance improvement can be expected. From the results of the performance modeling of the micro-bolometer with self-align thermal resistor for a $25{\mu}m$ pitch $640{\times}480$ microbolometer designed with $0.6{\mu}m$ minimum feature size, the drastic improvements of NETD from 38.7 mK to 19.1 mK, responsivity of 1.9 times are expected with a self aligned thermal resistor structure. The main reason for the performance improvements with a self-aligned thermal resistor structure comes from the increasement of the thermal resistance.

• Journal of Korea Port Economic Association
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• v.34 no.3
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• pp.159-182
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• 2018

The purpose of this study is to increase the competitiveness of big data in the maritime port organization, by understanding the expected performance and the intention to accept and use big data. In the empirical analysis of factors affecting the intention to use the big data technology for maritime port organizations, the variables employed are based on the Technology Organization Environment(TOE) and Diffusion of Innovations(DOI) theories, which are related to the acceptance of information and communication technologies. To achieve the objective of this study, an empirical analysis was conducted; this analysis targeted the personnel involved in the department of strategic planning and information technology in the related field. We set up eight hypotheses to examine the relevance between variables having three characteristics-technology, organization, and environmental characteristics. The empirical results are summarized as follows. First, it was seen that the technology characteristic, including relative advantage, complexity, and compatibility, has a significant effect on the expected performance. Second, the top management support of the organization characteristic has a significant effect, but the firm size of this characteristic has no significant effect on the expected performance. Third, the competitive pressure of the environment characteristic has a positive effect on the expected performance, while the regulatory support has no significant effect. Finally, the expected performance has a significant effect on the intention to use big data.

• Journal of the Korean Society for Library and Information Science
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• v.58 no.2
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• pp.251-268
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• 2024

Recently, with the implementation of the "e-Government Performance Management Guidelines," there is a growing demand for setting performance indicators for information systems. For systems that provide information services to the public, such as CODIL, it is not easy to set performance indicators. This study presented a research model that applies Monte Carlo simulation to set expected performance targets that can be achieved through CODIL based on objective evidence. Among the survey contents conducted from 2015 to 2023, the statistical characteristics of user satisfaction regarding the frequency of use of construction technology information provided by CODIL were designated as input variables. Future expected targets and confidence intervals from 2024 to 2026 were designated as outcome variables. The expected target value was measured by generating 5 simulation alternatives and 1,000 random numbers for each alternative. Next, the measured expected goals were interpreted and compared with the results of time series regression analysis measured in previous studies. Although, as in previous studies, the expected target value could not be predicted based on time series regression analysis that considers the correlation between years. However, compared to previous studies, this study can be considered a more accurate analysis result because it predicted the expected target value based on 5,000 input variables.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.3
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• pp.137-153
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• 2009

In this paper, we present an analytic model that evaluates the performance of B-MAC protocol under contention transmission conditions of two senders in a single-hop wireless sensor network. Our model considers the impact of several important factors such as sleep cycle, the backoff mechanism and incoming traffic loads. After obtaining the service delay distribution of a sending node and expected delay of a receiving node, an iterative algorithm is presented for calculating the performance measures such as expected energy consumption usage per packet and latency. Simulation results show that the proposed analytic model can accurately estimate the performance measures under different traffic conditions.

• Journal of Information Technology Applications and Management
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• v.22 no.1
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• pp.109-130
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• 2015

This study aims to provide the results of a case study, based on the action research approach, in which an user-oriented management system for enterprise information systems operational performance is successful developed and applied. This study performs the research and summarizes the results by adopting 5-step approach of action research, i.e., diagnosing, action planning, action taking, evaluating and specifying learning. The most important lessons learned from the study include (1) operation performance measures should be established to be shared by the management and users; (2) evaluation and improvement activities should be performed continually; and (3) formula to calculate the measure should be evolved so that improvement initiatives can be identified. The results of the study are expected to provide the companies intending to develop a management system for enterprise information systems operational performance with the practical and useful information. In addition, it is expected to suggest the research results that can be utilized as a basis for future research in this area.

• The Journal of Society for e-Business Studies
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• v.2 no.2
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• pp.75-88
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• 1997

Many Korean banks and companies have adopted EDI to replace traditioanal paper documents by electronic ones, which can move much faster with greater accuracy, Also, it is expected to reduce overall costs and maintain good relationships with customers. However, in practice, the performance of EDI seems to be less than expected. The purpose of this paper is to identify the impact of environment and adoption factors on the performance of financial EDI. We proposed a model for the relationships based on the existing literature and peformed a survey of Korean commercial banks and companies using KTNET. The results of this study are as follows: First, the business environment represented by the size of companies and the frequency of transactions showed a negative impact on the performance in terms of efficiency, which is quite converse to the common belief. Second, the technical environment, including computing skills of users and operators, showed a positive impact on the performance in terms of effectiveness. Third, the clearer the adoption purpose, the higher is the performace as intended, while the initiative for the adoption process showed no significant impact.