• The Bulletin of The Korean Astronomical Society
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• v.39 no.2
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• pp.43.1-43.1
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• 2014

We report on the optical spectroscopic analysis of a Low Luminosity Quasi Stellar Objects (LLQSOs) sample at $z{\leq}0.06$ based on the Hamburg/ESO QSO survey (HES). To better relate the low-redshift Active Galactic Nucleus (AGN) to the QSO population it is important to study samples of the latter type at a level of detail similar to that of the low-redshift AGN. Powerful QSOs, however, are absent at low redshifts due to evolutionary effects and their small space density. Our understanding of the (distant) QSO population is, therefore, significantly limited by angular resolution and sensitivity. The LLQSOs presented here offer the possibility to study the faint end of this population at smaller cosmological distances and, therefore, in greater detail. This, in turn, provides information about the key ingredients with respect to fueling and feedback of QSOs, and their relative importance/strength. Here, we present results of the analysis of visible wavelength spectroscopy provided by the HES and the 6 Degree Field Galaxy Survey (6dFGS). Interesting differences in the taxonomy of the sources having both types of spectra have been noticed and will be discussed.

• Journal of Power Electronics
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• v.15 no.6
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• pp.1429-1437
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• 2015

A new parallel hybrid soft switching converter with low circulating current losses during the freewheeling state and a low output current ripple is presented in this paper. Two circuit modules are connected in parallel using the interleaved pulse-width modulation scheme to provide more power to the output load and to reduce the output current ripple. Each circuit module includes a three-level converter and a half-bridge converter sharing the same lagging-leg switches. A resonant capacitor is adopted on the primary side of the three-level converter to reduce the circulating current to zero in the freewheeling state. Thus, the high circulating current loss in conventional three-level converters is alleviated. A half-bridge converter is adopted to extend the ZVS range. Therefore, the lagging-leg switches can be turned on under zero voltage switching from light load to full load conditions. The secondary windings of the two converters are connected in series so that the rectified voltage is positive instead of zero during the freewheeling interval. Hence, the output inductance of the three-level converter can be reduced. The circuit configuration, operation principles and circuit characteristics are presented in detail. Experiments based on a 1920W prototype are provided to verify the effectiveness of the proposed converter.

• Journal of KIISE:Computer Systems and Theory
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• v.36 no.3
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• pp.199-209
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• 2009

In this paper, we suggest a stroke level of detail (LOD) based on a saliency density. On painter]y rendering, the stroke LOD has an advantage of making the observer concentrate on the main object and improving accuracy of expression. For the stroke LOD, it is necessary to classify the detailed and abstracted area. We divide the area on the basis of saliency distribution and the level of detailed expression is controlled based on the saliency information. 'We define that the area of which the saliency distribution is high is a major subject that an artist tries to express, it is described in detail. The area of which the saliency distribution is low is abstractly described. Each divided area has the abstraction level. And by adapting the brushes of which sizes are appropriate to each level, it is possible to express the area which needs to be expressed in details from the one which needs to be expressed abstractly.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1355-1358
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• 2003

This paper presents performance analysis of the embedded application, called EEMBC consisting of 5 categories and total 34 applications. We measured various performance metrics, such as code sizes, TLP(Thread Level Parallelism) using OpenMP API and ILP(Instruction Level Parallelism) on ARM-modeled SimpleScalar in detail. We show that the embedded applications have the similar characteristics as integer applications to deliver low ILP and TLP in our environment. They have many small loops, which result in large instruction overhead in TLP and loop control overhead in ILP.

• Journal of Korean Society for Quality Management
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• v.31 no.2
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• pp.194-204
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• 2003

It is very important to understand and interpret the meaning of the sigma level correctly through the Six Sigma project. Especially, the confusion over the relation between sigma level from the short-term point of view and defective proportion or DPMO from the long-term point of view may make a big gap between expected results of the Six Sigma project and real results in the field. The one-tail approximation is commonly used to calculate the sigma level both in most literatures introducing Six Sigma and actual cases of the Six Sigma project. Since the one-tail approximation undervalues the sigma level of the fields such as business and service of which the sigma level is generally low, however. there can be misleading results of the explanation of the sigma level and inappropriate project evaluation. This paper describes the relation between sigma level and defective proportion in detail and clears the difference between the one-tail and two-tail approximation.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.26-33
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• 2007

NPR is the area of research which does the image creation of the impression where the hazard person who creates made a human intimate image by the hand in objective. NPR in Cartoon-Rendering when the human being recognizes a thing, it is a technique which expresses a thing to use an appearance and the line which are a means of basic and intuitional expression. Also Cartoon the person probably is, the hazard which helps, raises the efficiency of namely meaning delivery and a simplification technique with the means for it uses. Is like this cartoon basic rules where the simplification and omission are life, from modeling, the low of LOD technique which it is using specially actively from game and one pulse communication is having a common point. The research which it sees Cartoon effects of GPU bases which use DirectX Shader programs LOD it leads and it applies the method for about under presenting it expresses Cartoon effects in exterior.

• Journal of Distribution Research
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• v.3 no.1
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• pp.71-98
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• 1998

This study aimed to investigate how such retailers as department stores, large discount stores, book wholesalers, and clothing wholesalers used information technology for the QR strategy and whether the QR strategy had an effect on performance with a focus on the pipeline strategy. For this purpose, the QR strategy was divided into transaction efficiency, supplier partnership, and customer detail strategy. The differences in performance and information technology were analyzed according to the fit of the pipeline strategy, such as internal focus, supplier focus, and customer focus, the business strategy which were used by the retailers. And, an attempt was made to investigate whether performance was raised according to the level of adopting information technology. The results can be summarized as allows. First, the adaptive level of information technology had an effect on performance. But, seeing that the explanatory power of the regression analysis on the effect of the adaptive level of information technology on performance was shown to be very weak, it is judged that the level of QR information technology in the responding firms was very low compared to that of foreign firms. Second, information technology used by the retailers included universal product code, bar coding, customer database, and information utilities. It was shown that the group of firms seeking the transaction efficiency QR strategy and the internal focus pipeline strategy had the higher level of information technology than the retailers seeking other customer detail QR strategy and the customer focus pipeline strategy and the retailers with inconsistent strategy. This indicates that the firm seeking to raise its internal efficiency has a high level of using information technology. At the end of the paper, managerial implication and future research directions were discussed.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.6
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• pp.821-827
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• 2003

Fully developed turbulent flow in a square duct is numerically predicted with two nonlinear low-Reynolds-number ${\kappa}-{\varepsilon}$ models. Typical predicted quantities such as axial and secondary velocities, turbulent kinetic energy and Reynolds stresses are compared in detail with each other. It is found that the nonlinear low-Reynolds-number ${\kappa}-{\varepsilon}$ model adopted in a commercial code is unable to predict accurately duct flows involving turbulence-driven secondary motion with the prediction level of secondary flows one order less than that of the experiment.

• Journal of Computational Design and Engineering
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• v.2 no.1
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• pp.16-25
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• 2015

Since construction projects are large and complex, it is especially important to provide concurrent construction process to BIM models with construction automation. In particular, the schematic Quantity Take-Off (QTO) estimation on the BIM models is a strategy, which can be used to assist decision making in just minutes, because 70-80% of construction costs are determined by designers' decisions in the early design stage. This paper suggests a QTO process and a QTO prototype system within the building frame of Open BIM to improve the low reliability of estimation in the early design stage. The research consists of the following four steps: (1) analyzing Level of Detail (LOD) at the early design stage to apply to the QTO process and system, (2) BIM modeling for Open BIM based QTO, (3) checking the quality of the BIM model based on the checklist for applying to QTO and improving constructability, and (4) developing and verifying a QTO prototype system. The proposed QTO system is useful for improving the reliability of schematic estimation through decreasing risk factors and shortening time required.

• Nuclear Engineering and Technology
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• v.44 no.8
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• pp.911-918
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• 2012

Steam generator level control at low power is difficult due to its adverse thermal hydraulic properties, and is usually conducted by an operator. The basic model predictive control (MPC) is similar to the action of an operator in that the operator knows the desired reference trajectory for a finite period of time and takes the necessary control actions needed to ensure the desired trajectory. An MPC is based on a model; the performance as well as the efficiency of the MPC depends heavily on the exactness of the model. In this study, steam generator models that can describe in detail its thermal hydraulic behaviors, particularly at low power, are used in the MPC design. The design scope is divided into two parts. First, the MPC feedwater controller of the feedwater station is determined, and then the MPC level controller for the overall system is designed. Because the dynamic properties of a steam generator change with the power levels, a realistic situation is simulated by changing the transfer functions of the steam generator at every time step. The resulting MPC controller shows good performance.