• 한국기계가공학회지
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• 제20권11호
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• pp.17-23
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• 2021

A cyclone is a dust-separating mechanism that works on the principle of centrifugal force. The performance of a cyclone is evaluated using pressure loss and collection efficiency. A multi-cyclone arrangement is used to improve the collection efficiency within a limited area. In this study, experiments and numerical analyses were conducted on a dual arrangement of mini-hydrocyclone separators, which was fabricated using 3D printing. The experiment was performed at an inlet flow rate of 0.7 m/s, and alumina powder with a particle size of 0.5, 15, and 50 ㎛. ANSYS FLUENT, was used for the numerical analysis. The reliability of the numerical analysis was verified through a comparison with the experimental results. The errors in the experiment and numerical analysis were confirmed to be 2% at the outlet flow rate.

• Journal of the Korean Statistical Society
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• 제27권2호
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• pp.153-163
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• 1998

We investigate density estimation problem in the L$^{\infty}$ norm and show that the iii optimal minimax rates are achieved for smooth classes of weakly dependent stationary sequences. Our results are then applied to give uniform convergence rates for various problems including the Gibbs sampler.

• 한국융합학회논문지
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• 제7권4호
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• pp.217-227
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• 2016

본 논문은 우리나라 사회복지서비스가 지역 간 수렴하고 있는지를 분석하고 있다. 본 논문에서는 사회복지서비스가 지방공공재로서 어느 정도의 혼잡도를 갖는 것을 고려하여 1985-2013년 기간 동안 우리나라의 지역간 수렴을 분석한 결과 절대적인 사회복지서비스가 수렴하는 것이 실증적으로 입증되어 -수렴이 존재하는 것으로 드러났다. 또한 초기연도에 사회복지서비스의 수준에 반비례하여 사회복지서비스의 증가율이 결정되어 지역 간 사회복지서비스가 수렴하는 소위 -수렴이 존재하는 것으로 나타났다. 본 논문의 정책적 시사점으로는 첫째 지자체가 사회복지정책을 수행할 때 사회복지서비스의 혼잡도를 고려하여야 한다는 것이다. 둘째, 사회복지정책은 지방정부에서 차별적으로 수행하는 것보다는 국가전체의 관점에서 최소한의 복지서비스를 제공하는 것이 바람직하다는 것이다.

• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1264-1275
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• 2002

This paper is concerned with the investigation on the stability and convergence characteristics of the Crank-Nicolson-Galerkin scheme that is widely being employed for the numerical approximation of parabolic-type partial differential equations. Here, we present the theoretical analysis on its consistency and convergence, and we carry out the numerical experiments to examine the effect of the time-step size △t on the h- and P-convergence rates for various mesh sizes h and approximation orders P. We observed that the optimal convergence rates are achieved only when △t, h and P are chosen such that the total error is not affected by the oscillation behavior. In such case, △t is in linear relation with DOF, and furthermore its size depends on the singularity intensity of problems.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2003년도 The Fifth Asian Computational Fluid Dynamics Conference
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• pp.175-177
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• 2003

The convergence characteristics of the LV scheme for the Euler equations have been investigated by using the Von Neumann stability analysis. The results indicated that the convergence rate is governed by a specific combination of CFD parameters. Based on this insight, it is shown that the convergence characteristics of the LV scheme is not deteriorated at any grid aspect-ratio as long as the local time step is defined based on the parameter combination. The numerical results demonstrated that this time step definition provide a uniform convergence for grid aspect-ratios between one to$1{\times}10^{4}$.

• ETRI Journal
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• 제32권4호
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• pp.626-629
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• 2010

In this letter, we present an enhanced block-based adaptive loop filter (E-BALF) with multiple filter symmetric structures. The E-BALF adapts various filter symmetric structures in a rate-distortion optimization sense, reflecting the statistical properties of each image in a video sequence. Experimental results show that the proposed method achieves a reduction in the Bj${\phi}$ntegaard delta (BD)-bitrate by an average of 9.60% compared with Joint Model 11.0 of H.264/AVC. Compared to the state-of-the-art BALF, a reduction of up to 1.13% in BD-bitrate is achieved.

• 대한산업공학회지
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• 제42권3호
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• pp.209-221
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• 2016

As the ICT is an industry which is the basis of the technology convergence, it is the driving force of development for new business opportunities and existing industries. But, most of the existing studies for ICT convergence have identified the trend for convergence in technological terms. So, it is difficult to identify the convergence trend in the subject innovation perspective which leads the innovation activities In the ICT industry. The newly entered companies in the ICT industry are key indicators to identify the convergence trend. They have two specific characteristics that show the wide range of the convergence technology and the application rate of the convergence. Because previous studies did not take into account these two characteristics of the newly entered companies, so it is hard to analyze the exact convergence trend. Therefore, in this paper, we classify the patents for the ICT industry depending on the subject innovation. Then, we deduct the core convergence technology in the ICT industries and application area of the non-ICT industries.

• ETRI Journal
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• 제30권6호
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• pp.850-852
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• 2008

This letter presents a power efficient 64-state Viterbi decoder (VD) employing a two-stage radix-4 add-compare-select architecture. A class of VD architectures is implemented, and their hardware complexity, maximum operating speed, and power consumption are compared. Implementation results show that the proposed VD architecture is suitable for multiband orthogonal frequency-division multiplexing (MB-OFDM) ultra-wideband (UWB) systems, which can support the data rate of 480 Mbps even when implemented using 0.18-${\mu}m$ CMOS technology.

• 대한수학회지
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• 제36권2호
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• pp.299-316
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• 1999

We consider two finite difference approxiamations to a singular boundary value problem arising in the study of a nonlinear circular membrane under normal pressure. It is shown that the rates of convergence are O(h) and O($h^2$), respectively. An iterative scheme is introduced which converges to the solution of the finite difference equations. Finally the numerical experiments are given

• Journal of the Korean Statistical Society
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• 제31권2호
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• pp.261-276
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• 2002

Probability density or its derivatives may have a discontinuity/change point at an unknown location. We propose a method of estimating the location and the jump size of the discontinuity point based on kernel type density or density derivatives estimators with one-sided equivalent kernels. The rates of convergence of the proposed estimators are derived, and the finite-sample performances of the methods are illustrated by simulated examples.