• Nuclear Engineering and Technology
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• 제53권1호
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• pp.69-78
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• 2021

Venturi meter is frequently used in feed water flow control system in a nuclear power plant. Its accurate measurement plays a vital role in the safe operation of the plant. This paper firstly investigates the influence of the length of each section of pipeline, the throat inner diameter of Venturi and the flow characteristics in a single-phase flow on the accuracy of Venturi measurement by numerical calculation. Then the flow and the accuracy are discussed in a multi-phase flow. Numerical results show that the geometrical parameters and the characteristics of complex turbulent flow in the single-phase flow have little impact on the accuracy of Venturi flow rate measurement. In the multi-phase flow, the calculated flow rate of Venturi deviated from the actual flow rate and this deviation value is closely related to the amount of steam in the pipeline and increases sharply with the increase of the amount of steam. The over-reading of Venturi flow rate is present.

• 한국컴퓨터정보학회논문지
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• 제24권3호
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• pp.65-75
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• 2019

Non-Functional Requirements (NFR) play a crucial role during the software development process. Currently, NFRs are considered more important than Functional Requirements and can determine the success of a software system. NFRs can be very complicated to understand due to their subjective manner and especially their conflicting nature. Self-adaptive systems (SAS) are operating in dynamically changing environment. Furthermore, the configuration of the SAS systems is dynamically changing according to the current systems context. This means that the configuration that manages the trade-off between NFRs in this context may not be suitable in another. This is because the NFRs satisfaction is based on a per-context basis. Therefore, one context configuration to satisfy one NFR may produce a conflict with another NFR. Furthermore, current approaches managing Non-Functional Requirements trade-off stops managing them during the system runtime which of concern. To solve this, we propose fragmentizing the NFRs and their alternative solutions in form of Multi-entity Bayesian network fragments. Consequently, when changes occur, our system creates a situation specific Bayesian network to measure the impact of the system's conditions and environmental changes on the NFRs satisfaction. Moreover, it dynamically decides which alternative solution is suitable for the current situation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권12호
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• pp.5917-5935
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• 2018

Adaptive Multi-Rate Codec is one of the codecs which is used for making voice calls. It helps to connect people who are scattered in various geographical areas. It adjusts its bit-rate according to the user's channel conditions. It plays a vital role in providing an improved speech quality of voice connection in Long Term Evolution (LTE). There are some constraints which need to be addressed in providing this service profitably. Quality of Service (QoS) is the dominant mechanism which determines the quality of the speech in communication. On several occasions, number of users are trying to access the same channel simultaneously by standing in a particular region for a longer period of time. It refers to Multi-user channel sharing problem which leads to resource loss very often. The main aim of this paper is to develop a novel RSA - QoS scheduling algorithm for reducing the Resource Loss Ratio. Eventually, it increases the throughput.The simulation result shows that the RSA - QoS increases the number of users for accessing the resources better than the existing algorithms in terms of resource loss and throughput. Ultimately, it enhances the QoS in Mobile Networks.

• Advances in materials Research
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• 제7권3호
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• pp.195-201
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• 2018

High Strength low alloy steels containing various levels of C, Nb and Mn were used and for each of which, a simulated double thermal cycle was applied with the same first peak temperature and different second peak temperatures to produce HAZ microstructure corresponding to multi-pass weld. Effect of double cycle second temperature on the microstructure was observed and compared with single cycle results obtained from previous works, it was found that the percentage of martensite austenite constituent (MA) increases by Nb addition for all steels with the same Mn content and the increase in Mn content at the same Nb content shows an increase in MA area fraction as well. MA area fraction obtained for the double cycle is larger than that obtained for the single cycle for all steels used which imply that MA will have great role in the brittle fracture initiation for double cycle and the inter-pass temperature should be controlled for medium and high-carbon Mn steel to avoid large area fraction of MA. The beneficial effects of Niobium obtained in single pass weld were not observed for the double cycle or multi pass welds.

• Medical Lasers
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• 제9권1호
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• pp.12-24
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• 2020

Human fibroblast-derived multi-peptide factors (MPFs) have been used during treatments with energy-delivering modalities to enhance energy-induced tissue reactions. Human fibroblast-derived MPFs, which include a range of growth factors and chemoattractive factors, activate and recruit fibroblasts and endothelial cells, as well as promote extracellular matrix deposition, all of which are crucial to wound repair. Interestingly, fibroblasts from different species or anatomical sites exhibit distinct transcriptional properties with high heterogeneity. In addition, the patterns of MPF secretion can differ under a range of experimental conditions. Therefore, the use of allogeneic fibroblasts and proper cultivation thereof are necessary to obtain MPFs that can enhance the epithelial-mesenchymal interactions during wound repair. Moreover, energy-delivering devices should be selected according to evidence demonstrating their therapeutic efficacy and safety on a pathological skin condition and the major target skin layers. This paper reviewed the histologic patterns of post-treatment tissue reactions elicited by several energy sources, including non-ablative and ablative fractional lasers, intense focused ultrasound, non-invasive and invasive radiofrequency, picosecond-domain lasers, and argon and nitrogen plasma. The possible role of the immediate application of human fibroblast-derived MPFs during wound repair was proposed.

• Wind and Structures
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• 제35권5호
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• pp.297-307
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• 2022

Over the past few decades, the use of wind tunnels has been increasing as a result of the rapid growth of cities and the urge to build taller and non-typical structures. While the accuracy of a wind tunnel study on a tall building requires several aspects, the precise extraction of wind pressure plays a significant role in a successful pressure test. In this research study, a low-cost expandable synchronous multi-pressure sensing system (SMPSS) was developed and validated at Ryerson University's wind tunnel (RU-WT) using electronically scanning pressure sensors for wind tunnel tests. The pressure system consists of an expandable 128 pressure sensors connected to a compact data acquisition and a host workstation. The developed system was examined and validated to be used for tall buildings by comparing mean, root mean square (RMS), and power spectral density (PSD) for the base moments coefficients with the available data from the literature. In addition, the system was examined for evaluating the mean and RMS pressure distribution on a standard low-rise building and were found to be in good agreement with the validation data.

• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.176-181
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• 2011

A role of cost modeler is that of facilitating design process by the systematic application of cost factors so as to maintain sensible and economic relationships between cost, quantity, utility and appearance. These relationships help to achieve the client's requirements within an agreed budget. The purpose of this study is to develop a parametric cost estimating model for the early design stage by using the multi-dimensional system of OLAP (On-line Analytical Processing) based on the case of quantity data related to architectural design features. The parametric cost estimating models have been adopted to support decision making in the early design stage. These models typically use a similar instance or a pattern of historical case. In order to effectively use this type of data model, it is required to set data classification and prediction methods. One of the methods is to find the similar class in line with attribute selection measure in the multi-dimensional data model. Therefore, this research is to analyze the relevance attribute influenced by architectural design features with the subject of case-based quantity data used for the parametric cost estimating model. The relevance attributes can be analyzed by Analytical Characterization. It helps determine what attributes to be included in the OLAP multi-dimension.

• 한국수소및신에너지학회논문집
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• 제35권2호
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• pp.129-139
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• 2024

The significance of hydrogen economy and production technology is steadily increasing. This research reviewed strategies for utilizing hydrogen production technology by combining a multi-layer model, strategic niche management, and the need factor for Hoship. The model was validated as a strategy considering hydrogen production technology and the transformation of the energy system. Using this, a new business model for hydrogen production technology was created, finding a strategic niche and sophisticating the technology. It also proposed ways to unlock the potential of hydrogen production technology and improve its efficiency. This work contributes to the commercialization of hydrogen production technology and its role in sustainable energy conversion. It proposes a new and effective approach for utilizing hydrogen production technology, going beyond its limitations to suggest a more efficient method. It is hoped that these results will be helpful to researchers in hydrogen energy, and serve as a reference for establishing ways to utilize hydrogen production technology.

• 대한지리학회지
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• 제38권3호
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• pp.400-412
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• 2003

신 정보통신기술(ICTs)이 기업의 비즈니스 처리방식을 변화시키고 있다는 점은 일반적으로 받아들여지고 있다. 예를 들어. 기업의 내부자원 관리의 효율성을 제고하기 위한 ERP(enterprise resources planning)와 BPR(business process reengineering) 활용. 공급 연줄망을 통합하기 위한 기업-기업간 e-com의 적용. 그리고 기업-고객간 e-com과 같이 새로운 마켓팅 통로의 창출 등을 들 수 있다. 기업들은 이러한 새로운 방식의 비즈니스가 기업의 생산성 증대 및 개래비용의 절감 효과를 가져온다고 확신한다. 그 결과. 신 ICTs는 다양한 제품을 생산하는 많은 소규모 기업들의 최근 성장과 국제화를 통한 공간적 확산에 중요한 역할을 하고 있다. 본 연구는 중국 Haier 기업을 사례로 기업의 성장과정에 신 ICTs가 끼친 역할을 살펴본 것이다. Haier 기업은 1990년부터 2002년 시기에 초국적 기업으로 성장했는데, 그 배경으로 신 ICTs의 채택과 관련하여 기업의 국제화 과정을 연구한 것이다. 연구결과, Haier 기업의 신 ICTs의 채택은 세계 여러 지역에 위치한 기능체의 통합에 기여했으며. 이는 기업의 국제화에 필수적인 적기생산과 배달체계를 구축함으로써 세계적으로 광범위한 지역의 공급자와 구매자를 가깝게 연계시키는 결과를 가져왔다. 결론적으로 Haier 기업은 신 ICTs를 활용함으로써 10년 이내에 초국적기업으로 성장하게 되었다는 점이다.

• 한국재료학회지
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• 제12권11호
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• pp.840-844
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• 2002

A spherical $BaMgAl_{10}$ $O_{17}$ :Eu phosphor has been synthesized by a multi-step precipitation route. In order to successfully synthesize the phosphor with spherical shape, the hydrated-alumina particles should be controlled for spherical shape. In this process, the hydroxypropyl cellulose (HPC) was used as a dispersing reagent. This reagent plays an important role in that the particles were controlled to have the uniform size of sub-micron. The final product prepared by the multi-step precipitation method maintained spherical shape with uniform size of 0.4$\mu\textrm{m}$. It can be seen in X-ray diffraction patterns, formation of the single phase of $BaMgAl_{10}$ $O_{17}$ :Eu phosphor prepared by the multi-step precipitation method at $1350^{\circ}C$. Also, the emission spectra of spherical $BaMgAl_{O}$ $10_{17}$ :Eu phosphor in the present case was compared with those of commercially-available blue phosphor under VUV (Vacuum Ultra Violet) excitation. The luminescence process of the $BaMgAl_{10}$ $O_{17}$ :Eu phosphor is characterized by the $4f^{6}$$5d^1$longrightarrow4f$^{7}$ transition (blue) of the $Eu^{2+}$ ion acting as an activating center and the maximum luminescence intensity was obtained by reduction treatment at 145$0^{\circ}C$.