• 응용통계연구
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• 제20권3호
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• pp.597-604
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• 2007

현대 사회에서 건강관리와 공중보건 분야의 이상원인 탐지와 감시를 위하여 관리도 기법을 많이 사용하고 있다 예를 들어, 외과의사의 수술 수행성과의 변화나 만성병과 전염병 등의 비율 변화를 탐지하는데 관리도를 사용할 수 있다. 이 논문에서는 건강관리와 공중보건 분야에서 많이 사용하는 VLAD (variable life-adjusted display) 관리도를 소개하고, 이 관리도에서 관리한계선을 설정하는 방법을 제안하였다.

• 품질경영학회지
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• 제30권4호
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• pp.1-14
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• 2002

Traditional SPC techniques are looking out variation of process by fixed sampling interval and fixed sample size about every hour, the process of in-control or out-of-control couldn't be detected actually when the sample points are plotted near control limits, and it takes no notice of expense concerned with such sample points. In this paper, to overcome that, consider VSI(variable sampling interval) EWMA control charts which VSI method is applied. The VSI control charts use a short sampling internal if previous sample points are plotted near control limits, then the process has high probability of out-of-control. But it uses a long sampling interval if they are plotted near centerline of the control chart, since process has high possibility of in-control. And then a comparison and analysis between FSI(fixed sampling interval) and VSI EWMA in the statistical aspect and economic aspect is studied. Finally, we show that VSI EWMA control chart is more efficient than FSI EWMA control chart in the both aspects.

• Steel and Composite Structures
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• 제9권4호
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• pp.303-323
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• 2009

Charts for the bending moments in the closed rib orthotropic deck plate are derived, based on the method originally introduced by Pelikan and Esslinger. New charts are done for EN 1991-2 traffic load distribution schemes. The governing Huber plate equation is solved utilizing Fourier series for various bridge deck plate boundary conditions. Bending moments are given as a function of deck plate rigidities and span length between cross beams. Old diagrams according to DIN 1072, the new ones according to EN 1991-2 and FE analyses results are compared. For typical bridge orthotropic deck plates, it can be concluded that the new EN 1991-2 traffic loads produce larger mid-span bending moments when two lane schemes are used, then those of DIN 1072. For support moments, DIN 1072 gives larger values for any number of lanes, especially under span lengths of 5m. The relevant differences are up to 25%.

• Geomechanics and Engineering
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• 제13권3호
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• pp.517-533
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• 2017

In this paper, with a graphical approach, a series of stability charts for homogeneous slopes with benches are presented based on the upper bound limit analysis theory and strength reduction technique. The objective function of the slope safety factor $F_s$ is optimized by the nonlinear sequential quadratic programming, and a substantial number of examples are illustrated to use the stability charts for homogeneous slopes with benches driven by only the action of the soil weight. These charts can be applied to quick and accurate estimations of the stability status of homogeneous slopes with benches. Moreover, the failure modes and the formula for safety factor Fs of homogeneous slopes with benches are provided to illustrate the stability analysis of slopes with benches, which is validated by samples.

• 통합자연과학논문집
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• 제14권3호
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• pp.116-122
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• 2021

Properties and comparison of multivariate CUSUM and EWMA charts for monitoring Σ of multivariate normal N(${\underline{\mu}}$, Σ) process has considered. Comparison of the performances of the considered charts, the numerical values are obtained by simulation with 10,000 iteration in terms of ATS, ANSS and ANSW. We found that EWMA chart with small values of smoothing constant more effectively detects the process changes than with large smoothing constant. And we also found that CUSUM chart with small value of reference value is more effectively detecting the process change than with large reference value. If a process engineer has interest in detecting small amount of shift rather than large shift, he/she can be recommended to use small smoothing constant in EWMA chart and small reference value in CUSUM chart.

• Structural Engineering and Mechanics
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• 제14권3호
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• pp.307-330
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• 2002

This study aims at postulating a simple methodology for predicting the failure modes of monotonically loaded reinforced concrete beam-column joints. All the factors that affect the failure modes of joints are discussed in detail using an experimental database of monotonically loaded exterior beam-column joints. The relative contributions of the strut and truss mechanisms to joint shear strength are determined based on the test results. A simple design equation for the beam longitudinal reinforcement ratio for joints with low, medium and high amount of stirrups is developed. The factors influencing the failure modes of monotonically loaded exterior beam-column joints are investigated in detail. Design charts that predict the failure modes of exterior beam-column connections both with and without stirrups are developed. Experimental data are compared with the design charts. The results show that the simple methodology gives very accurate predictions of the failure modes.

• 한국해양공학회지
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• 제18권3호
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• pp.20-25
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• 2004

For the structural foundation above the soft clay layer conditions, the design charts are first presented for the evaluation of both bearing capacity and total settlement in the basic raft foundation system. wad settlement relationship curves are used to evaluate the ultimate soil bearing capacity. The total settlement is evaluated by applying various traditional factors into the ultimate bearing capacity. Then, the parametric studies are carried out for the piled-raft foundation system. In the numerical analysis, the elasto-pastic finite element model(Mohr-Coulomb model) is used to present the foundation response and design charts, which enable the determination of the raft size and pile length and spacing.

• Structural Engineering and Mechanics
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• 제47권2호
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• pp.185-207
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• 2013

In flexural strength design of normal-strength concrete (NSC) beams, it is commonly accepted that the distribution of concrete stress within the compression zone can be reasonably represented by an equivalent rectangular stress block. The stress block it governed by two parameters, which are normally denoted by ${\alpha}$ and ${\beta}$ to stipulate the width and depth of the stress block. Currently in most of the reinforced concrete (RC) design codes, ${\alpha}$ and ${\beta}$ are usually taken as 0.85 and 0.80 respectively for NSC. Nonetheless, in an experimental study conducted earlier by the authors on NSC columns, it was found that ${\alpha}$ increases significantly with strain gradient, which means that larger concrete stress can be developed in flexure. Consequently, less tension steel will be required for a given design flexural strength, which improves the ductility performance. In this study, the authors' previously proposed strain-gradient-dependent concrete stress block will be adopted to produce a series of design charts showing the maximum design limits of flexural strength and ductility of singly-and doubly-NSC beams. Through the design charts, it can be verified that the consideration of strain gradient effect can improve significantly the flexural strength and ductility design limits of NSC beams.

• Industrial Engineering and Management Systems
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• 제6권1호
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• pp.11-21
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• 2007

The PDCA (Plan, Do, Check and Act) cycle is often used in the field of quality management. Recently, business environments have become more competitive, and the due time of products has shortened. In a short production run process, to increase efficiency of management, the necessity for distinguishing the PDCA design that starts with PLAN and the CAPD design that starts with CHECK has been clarified. Starting from Duncan (1956), there have been a number of papers dealing with the economic design of control charts from the viewpoint of production run. Some authors (Gibra, 1971; Ladany and Bedi, 1976; etc.) have studied the economic design for finite-length runs; other authors (Crowder, 1992; Del Castillo and Montgomery, 1996; etc.) have studied the economic design for short runs. However, neither the PDCA nor the CAPD design of control charts has been considered. In this paper, both the PDCA and CAPD designs of the $\bar{\x}$ chart are defined based on Del Castillo and Montgomery's design (1996), and their mathematical formulations are shown. Then from an economic viewpoint, the optimal values of the sample size per each sampling, control limits width, and the sampling interval of the two designs are studied. Finally, by numerically analyzing the relations between the key parameters and the total expected cost per unit time, the comparisons between the two designs are considered in detail.

• 대한전자공학회논문지
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• 제19권6호
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• pp.9-16
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• 1982

이 설계 과정은 보통의 더지탈 하아드웨어 담계에 복합 기계 개념을 응용한 일설계 기법을 소개한 것이다. 이 과정은 계산기용 소프트웨어 설계의 경우와 마찬가지로 새 시스템을 흐름도에 의해 표현시키는 것으로 부터 시작되며, 이어서 흐름도를 분해하여 발산형 요소를 얻고, 이 발산형 요소를 근거로 소기계를 작성하게 되는데, 이렇게 소기계의 작성이 끝나게 되면. 이번에는 통합 과정을 통해서 복합체와 지시기를 만들고, 논리자로를 완척함으로써 전휴의 설계 과정을 완료하게 된다. This is an introduction to an art of digital hardware design using polymachine image as a target structure of the product. As in the case of software design of a computer, the design process begins with a sketch of planned system in flow chart description and the flow charts is partitioned into divergent elements. Each of the element machine is derived from those divergent elements. We can build a complete digital system with the preparation of an index, and a polymer of these element machines.