• Journal of Preventive Medicine and Public Health
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• 제55권1호
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• pp.10-18
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• 2022

Disability-adjusted life-year (DALY) estimates may vary according to factors such as the standard life expectancy, age weighting, time preference and discount rate, calculation of disability weights, and selection of the estimation method. DALY estimation methods are divided into the following 3 approaches: the incidence-based approach, the pure prevalence-based approach, and the hybrid approach. These 3 DALY estimation approaches each reflect different perspectives on the burden of disease using unique characteristics, based on which the selection of a suitable approach may vary by the purpose of the study. The Global Burden of Disease studies, which previously estimated DALYs using the incidence-based approach, switched to using the hybrid approach in 2010, while the National Burden of Disease studies in Korea still mainly apply the incidence-based approach. In order to increase comparability with other international burden of disease studies, more DALY studies using the prevalence-based approach need to be conducted in Korea. However, with the limitations of the hybrid approach in mind, it is necessary to conduct more research using a disease classification system suitable for Korea. Furthermore, more detailed and valid data sources should be established before conducting studies using a broader variety of DALY estimation approaches. This review study will help researchers on burden of disease use an appropriate DALY estimation approach and will contribute to enhancing researchers' ability to critically interpret burden of disease studies.

• 서비스연구
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• 제8권1호
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• pp.59-72
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• 2018

서비스 관점에서 국제표준기구가 요구하는 수준의 인증 서비스를 SW 개발과정에 도입하는 것은 매우 중요하다. 그 이유는 우리 산업에서 ICT가 차지하는 비중이 매우 높을 뿐만 아니라, ICT 관련 SW에 대한 국제적인 수준의 인증은 필수적이기 때문이다. 그리고 이를 위해서 ADONIS와 같은 과학적이며 체계적인 도구를 기반으로 한 인증 서비스가 절대적으로 요구된다. 본 논문에서는 이러한 시대적, 사회적 요구에 부응할 수 있는 하나의 새로운 방법 체계를 제시하였다. 이 체계는 우리 산업에 국제적인 수준에서 요구되는 SW의 안전성에 대한 인증 서비스를 제공하였고, 이러한 서비스는 다른 영역에도 적용될 수 있다. 이러한 체계를 설명하기 위해 EU우주항공국의 표준안 중 ECSS-E-40의 인증을 위한 서비스의 설계와 이에 대한 보증이 어떻게 이루어지는지 서비스 공학 측면에서 살펴보고, ADONIS를 통해서 보여주고자 한다. 본 논문은 E-40 표준안의 항목 중 SW의 명세와 검증에 관해 집중하며, 검증의 대상은 안전성(Safety)을 우선으로 한다.

• 한국농공학회논문집
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• 제59권3호
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• pp.11-19
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• 2017

The decision-making process is the act of finding the best solution among various alternatives through comparison between various criteria based on objectives of the project, evaluation standard, and conditions. However, in practice it is not easy to simply decide the optimum decision, especially for selecting malfunctioning reservoirs because no systematic evaluation criteria or standard assessment process are available. Therefore, this study adopted AHP method, which is a MCDM (multi-criteria decision making technique) to identify the malfunctioning reservoirs for efficient management of reservoirs. Important criteria of the selection of malfunctioning reservoirs and priority weights of each criteria were determined based on results of expert's survey under a stepwise hierarchical approach. The most important factor for the decision of malfunctioning reservoirs was obtained as Reservoir efficiency among the selected criteria including Reservoir efficiency decrease, Disaster Risk, Reservoir efficiency, Available water storage, Future water demand, Resident Needs. The AHP technique was applied on 11 reservoirs in Andong region to verify its applicability. Scoring method was applied for the comparison with the results of AHP method.

• Wind and Structures
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• 제17권3호
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• pp.263-274
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• 2013

A numerical technique for fluid-structure interaction, which is based on the finite element method (FEM) and computational fluid dynamics (CFD), was developed for application to an industrial chimney equipped with a pendulum tuned mass damper (TMD). In order to solve the structural problem, a one-dimensional beam model (Navier-Bernoulli) was considered and, for the dynamical problem, the standard second-order Newmark method was used. Navier-Stokes equations for incompressible flow are solved in several horizontal planes to determine the pressure in the boundary of the corresponding cross-section of the chimney. Forces per unit length were obtained by integrating the pressure and are introduced in the structure using standard FEM interpolation techniques. For the fluid problem, a fractional step scheme based on a second order pressure splitting has been used. In each fluid plane, the displacements have been taken into account considering an Arbitrary Lagrangian Eulerian approach. The stabilization of convection and diffusion terms is achieved by means of quasi-static orthogonal subscales. For each period of time, the fluid problem was solved and the geometry of the mesh of each fluid plane is updated according to the structure displacements. Using this technique, along-wind and across-wind effects have been properly explained. The method was applied to an industrial chimney in three scenarios (with or without TMD and for different damping values) and for two wind speeds, showing different responses.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.556-564
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• 2021

Numerous spatial and transform-domain-based conventional denoising algorithms struggle to keep critical and minute structural features of the image, especially at high noise levels. Although neural network approaches are effective, they are not always reliable since they demand a large quantity of training data, are computationally complicated, and take a long time to construct the model. A new framework of enhanced hybrid filtering is developed for denoising color images tainted by additive white Gaussian Noise with the goal of reducing algorithmic complexity and improving performance. In the first stage of the proposed approach, the noisy image is refined using a high-dimensional non-local means filter based on Principal Component Analysis, followed by the extraction of the method noise. The wavelet transform and SURE Shrink techniques are used to further culture this method noise. The final denoised image is created by combining the results of these two steps. Experiments were carried out on a set of standard color images corrupted by Gaussian noise with multiple standard deviations. Comparative analysis of empirical outcome indicates that the proposed method outperforms leading-edge denoising strategies in terms of consistency and performance while maintaining the visual quality. This algorithm ensures homogeneous noise reduction, which is almost independent of noise variations. The power of both the spatial and transform domains is harnessed in this multi realm consolidation technique. Rather than processing individual colors, it works directly on the multispectral image. Uses minimal resources and produces superior quality output in the optimal execution time.

• Wind and Structures
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• 제18권5호
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• pp.567-598
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• 2014

In this paper, wind induced aerodynamic loads on a standard tall building have been evaluated through large-eddy simulation (LES) technique. The flow parameters of an open terrain were recorded from the downstream of an empty boundary layer wind tunnel (BLWT) and used to prescribe the transient inlet boundary of the LES simulations. Three different numerically generated inflow boundary conditions have been investigated to assess their suitability for LES. A high frequency pressure integration (HFPI) approach has been employed to obtain the wind load. A total of 280 pressure monitoring points have been systematically distributed on the surfaces of the LES model building. Similar BLWT experiments were also done to validate the numerical results. In addition, the effects of adjacent buildings were studied. Among the three wind field generation methods (synthetic, Simirnov's, and Lund's recycling method), LES with perturbation from the synthetic random flow approach showed better agreement with the BLWT data. In general, LES predicted peak wind loads comparable with the BLWT data, with a maximum difference of 15% and an average difference of 5%, for an isolated building case and however higher estimation errors were observed for cases where adjacent buildings were placed in the vicinity of the study building.

• 정보통신설비학회논문지
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• 제3권1호
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• pp.88-101
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• 2004

The Third Generation (3G) cellular mobile communication systems aim at providing higher data rates, improved quality of service, support for multimedia applications and global roaming. Cdma2000 and Universal Mobile Telecommunication System (UMTS) have emerged as two leading 3G standards in USA and European countries, respectively. Both the standards are capable of delivering high bandwidth data, voice and multimedia services to users of mobile equipment, but are not directly interoperableand are not available across different geographic areas, due to which global roaming is not possible in true sense of using single mobile equipment. However, both UMTS and cdma2000 are based on wideband code division multiple access (WCDMA) as the access method. Due to this, there exist some inherent commonalities between them. In this paper we will try to exploit the commonalities between the two standards in order to design an ASIC, which can provide dual standard capability. This paper discusses the physical layer aspects of the two standards and proposes an approach to design an ASIC which can be mapped to baseband processing part of the physical layer and is capable of delivering for either of the two aforementioned standards.

• 한국전자거래학회지
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• 제23권3호
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• pp.1-12
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• 2018

혼합 중요도 시스템은 중요도가 다른 컴포넌트의 조합으로 이루어져 있다. 최근 자동차 시스템과 항공기 시스템에서 사용되는 ISO 26262와 DO-178B 표준에서는 컴포넌트를 중요도에 따라 분류하고 있다. 기존 혼합 중요도 시스템 연구에서는 시스템 모드를 통해서, 효율적이면서 안전한 스케줄링을 추구했다. 이러한 연구의 단점은 고중요도 모드에서 저중요도 작업의 성능저하이다. 이러한 문제를 개선하고자 작업별 중요도 모드를 도입하여 저중요도 작업의 성능을 개선하고 확률적 성능 지표를 설계했다. 시뮬레이션을 통해서 기존 연구 대비 성능 향상 효과를 보였다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.720-728
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• 2009

This thesis is results of numerical analyses about test results of discharge capacity apparatus using penetration method. Applicability of numerical approach with FEM technique, using Cam-clay model, was confirmed by analyzing the results of standard consolidation test before analyzing test results of discharge capacity apparatus using penetration method. Thus, input parameters for the model was convinced to be appropriate. For numerical analyses about test results of discharge capacity apparatus using penetration method, identical initial and loading conditions during tests were applied to simulate test results correctly. Effects of ground disturbance resulted from installment of vertical drains on the behaviors of consolidation were also simulated. Applicability of numerical approach was investigated by comparing test results with numerical ones. As results of them, both of consolidation settlement were found to be in good agreements so that its applicability was confirmed. As results of numerical estimation, degree of consolidation with the condition of considering smear zone was found to be delayed, compared with results without smear zone. On the other hands, parametric numerical analyses of changing parameters related to smear zone such as permeability and size of smear zone and permeability of vertical drain were also carried out.

• 대한산업공학회지
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• 제28권4호
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• pp.407-414
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• 2002

The inherent reliability of a product is primarily determined in the design stage, and therefore, design engineers should be able to design reliability into the product in an efficient manner. Especially, the product should be designed such that its reliability is robust to various noise factors encountered in production and field environments. The Taguchi method can be effectively used for this purpose. However, there exist only a few attempts to integrate the Taguchi method with reliability design, and in addition, the existing works do not sufficiently consider the robustness and/or the distinction between noise and acceleration factors. This paper develops a unified approach to robust reliability design assuming that accelerated life tests are conducted at each combination of design and noise conditions. First, an experimental structure for assigning not only acceleration but also noise factors is presented. Second, the reliability at the use condition is estimated using the assumed accelerated life test model. Third, reliabilities are transformed into 'efforts' using an effort function which reflects the degree of difficulty involved in improving the reliability. Finally, an optimal setting of design parameters is determined based on the mean and standard deviation of the effort values. The above approach is illustrated with an example of a paper feeder design.