• The Korean Journal of Nuclear Medicine Technology
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• v.28 no.1
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• pp.35-40
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• 2024

Purpose: To improve the image quality in positron emission tomography (PET), the attenuation correction technique based on the computed tomography (CT) data is important process. However, the artifact is caused by metal material during PET/CT scan, and the image quality is degraded. Therefore, the purpose of this study was to evaluate image quality according to with and without iterative metal artifact reduction (iMAR) algorithm using customized 3D printing phantom. Materials and Methods: The Hoffman and Derenzo phantoms were designed. To protect the gamma ray transmission and express the metal portion, lead substance was located to the surface. The SiPM based PET/CT was used for acquisition of PET images according to application with and without iMAR algorithm. The quantitative methods were used by signal to noise ratio (SNR), coefficient of variation (COV), and contrast to noise ratio (CNR). Results and Discussion: The results shows that the image quality applying iMAR algorithm was higher 1.15, 1.19, and 1.11 times than image quality without iMAR algorithm for SNR, COV, and CNR. Conclusion: In conclusion, the iMAR algorithm was useful for improvement of image quality by reducing the metal artifact lesion.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1995.06b
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• pp.1-3
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• 1995

Aspects of the current trend in lubricants and future challenges are discussed. The discussion highlights key enviromnental issues regarding to resource conservation, toxicological consideration and environmental acceptability. Also highlighted are base stocks trends relative to hydroprocessed stocks (HVI, VHQ and XHQ), synthetic base stocks (PAO and organic esters) and biodegradable fluids (vegetable oils and special esters). Equipment severity and lubricant performance quality are briefly described.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.105-105
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• 2003

Theoretical studies have been performed for drainage and filtration characteristics, low consolidation rate of sandmat and prefabricated horizontal and vertical drain. Discussion on quality control and methodology, cost analysis for sandmat and prefabricated horizontal drains were performed.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07b
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• pp.897-897
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• 2005

We report QLA (Quenching-rate controlled Laser Annealing) system as new concept using pulsed DPSSL and CW lasers. This process can control temperature quenching-rate of poly-Si crystallization by additional CW laser and fabricate high quality poly-Si with faster scanning speed than conventional processes. In this paper, QLA system, the experimental results and theoretical discussion will be introduced.

• The Korean Journal of Applied Statistics
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• v.12 no.1
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• pp.309-313
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• 1999

To overcome current hardship during recent years of university reform, statistics departments of Korean universities should form a new shape with efficient strategies: First, they should value interdisciplinary and open education to foster scientific generalists rather than specialists (Bode.Mosteller.Tukey.Winsor, 1949). Second, they should work out on developing curriculum and improving educational quality for non-statistics majors (Ahn.Cho.Huh, 1994). The service market is widely open and its value is certainly worthy. Third, they may change their department name from "statistics", of which the social image is not quite right, to "data science" or "data information". Statistics is a field of learning on data methodology (Friedman, 1997). methodology (Friedman, 1997).

• Journal of Advanced Marine Engineering and Technology
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• v.29 no.3
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• pp.319-324
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• 2005

This paper reports the performance of Wind-PV(Photovoltaic) hybrid system. The output power of PV is affected by the environmental factors such as solar radiation and cell temperature. Also, the output power of wind system is generated with wind power. Integration of Wind and PV resources, which are generally complementary, usually reduce the capacity of the battery. This paper includes discussion on system reliability, power quality and effects of the randomness of the wind and the solar radiation on system design.

• Nuclear Engineering and Technology
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• v.42 no.4
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• pp.377-381
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• 2010

In 2007 the Nuclear Energy Agency's Committee on the Safety of Nuclear Installations published Best Practice Guidelines for the use of CFD in Nuclear Reactor Safety. This paper provides an overview of the document' contents and highlights a few of its recommendations. The document covers the full extent of a CFD analysis from initial problem definition and selection of an appropriate tool for the analysis, through final documentation of results. It provides advice on selection of appropriate simulation software, mesh construction, and selection of physical models. In addition it contains extensive discussion of the verification and validation process that should accompany any high-quality CFD analysis.

• Journal of Korean Society for Quality Management
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• v.42 no.2
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• pp.131-143
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• 2014

Purpose: This paper discusses the intrinsic assumption of one-dimensional relationship between the upper and lower levels in AHP(Analytic Hierarchy Process) for the Preliminary Feasibility Study of National R&D Program. This assumptions has not been questioned in academia and industry so far. Methods: This discussion is induced by understanding the Theory of Attractive Quality (Kano et al. 1984) and explains the limitation of AHP in the preliminary feasibility study of national R&D program. Results: In this paper, we propose a new questioning method based on two dimensional perspective, which is named as 2D-AHP (two dimensional AHP), to overcome the limitation. The main idea stems from the observation that the relationship between the upper and lower levels in AHP can vary depending on the subject of R&D. Conclusion: The two dimensional perspective pointed out in this paper should be more deeply studied in the field of MCDM(multi-criteria decision making) since it can be applied to the more general problems in human decision making.

• Journal of architectural history
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• v.13 no.4 s.40
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• pp.35-54
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• 2004

Perception of architectural experience is different in different culture. This paper aims to identify how the experience of architecture is understood to be different in Eastern and Western culture. The discussion is based on the idea that the Western architecture placed more emphasis on visual perception, while the Eastern, on mutual responsiveness between man and built environment. The fact that the Western culture is more visually oriented than other culture, and therefore visual aspect of architecture, too, is considered to be very important, is already widely agreed among scholars. But, then, what had been considered to be important in the architectural experience in the East? It is the degree and quality of mutual responsiveness between man and architectural environment. This fact influenced much on the making of architecture of course, and the same fact played the key role in making the Eastern architecture different from that of the West. We are so used to the way of architecture of the West, that the quality of responsiveness is unknown if not forgotten. However, it is not the quality that was useful only in traditional society of the East, but necessary in our modem period as well. The quality for responsiveness, therefore, should be rediscovered and restored as the prime value and quality of architecture in the future architecture.

• Journal of the Korean Society for Library and Information Science
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• v.32 no.3
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• pp.179-206
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• 1998

The purpose of this study is to discuss the theoretical and practical strategies for the quality management of a union database built in a distributed system. To the end, this study introduces the quality control methods employed for the OCLC union catalog, which has been built in a distributed system and also known as the most typical union DB. The main discussion is about the quality issue of KORDIC's SATURN DB, the most typical union DB in South Korea. The final recommendation includes the management strategies and practical guidelines for the efficient quality control of a union DB built in a distributed system.