• 상하수도학회지
• /
• 제25권5호
• /
• pp.635-642
• /
• 2011

Hydraulic efficiency was a vital component in evaluating the disinfection capability of clearwell. Current practice evaluates these system based on the tracer test only. In this paper, CFD(Computational Fluid Dynamics) was applied on the clearwell for alternating or supplementing the tracer test. The baffle factor derived from the CFD modeling closely matched the values obtained from full scale tracer testing. And, for suggesting proper numerical model in clearwell; the turbulence model, discretization scheme, convergence criteria were investigated through separate simulation runs. The model validation was conducted by comparing the simulated data with experimental data. In the turbulence model, the realizable ${\kappa}-{\varepsilon}$ model and the standard ${\kappa}-{\varepsilon}$ model were found to be more appropriate than RNG ${\kappa}-{\varepsilon}$ model. The residuals of convergence criteria should be used as not $10^{-3}$ but $10^{-4}$ or $10^{-5}$. In discretization scheme, the difference of simulated values in 1st, 2nd, 3rd upwind scheme was found to be insignificant. Moreover, the result of this study suggest that CFD modeling can be a reliable alternative to tracer testing for evaluating the hydraulic efficiency.

• 한국병원경영학회지
• /
• 제10권4호
• /
• pp.98-112
• /
• 2005

The purpose of this study is to develop a framework for evaluating security levels in hospitals. We classify security indicators into administrative, technical and physical safeguards. The security evaluation model for hospital information systems was applied to three general hospitals. The analysis of the results showed a low security level in information systems. In particular, requirements for administrative and physical safeguards were very low. Hospitals need strict security policies more than other organizations because their information systems contain patients' highly confidential data. The evaluation model developed in this study can be used for guidelines and as a checklist for hospitals. The security evaluation in hospital informational systems needs to be an essential element of hospital evaluation.

• 품질경영학회지
• /
• 제29권3호
• /
• pp.151-165
• /
• 2001

The purpose of this study is to develop systematic methods for evaluating the suitability of a seat and build an empirical model for predicting the suitability of a seat. The following research schemes were pursued to achieve the objectives - Development of suitable chair dimensions - Analysis scheme for decomposing the human-product interface system - Development of model for evaluating suitability. As a result, we uncovered six dominant suitability dimensions for the design of a comfortable seat that is related to the physical dimension of a body, Here, six suitability dimensions were identified as the dimensions that represent the human sensitivity and psychological feeling on comfortable seats. Also, 43 human-interface elements (HIE's) such as seat height, seat width, seat depth, tilting angle, seat surface etc. were investigated. HIE was generally defined as the physical characteristic of manufacturing goods, and it had close related to the body dimension of a user and environment that it was used.

• 한국경영정보학회:학술대회논문집
• /
• 한국경영정보학회 2007년도 International Conference
• /
• pp.764-769
• /
• 2007

This paper proposes a new model to· evaluate the effectiveness of websites using balanced scorecard (BSC) and weighted formula based methods.fisrt, we Use BSC method to find out the cause-and-effect relationships between the measure and website activities, and our proposed model evaluates website performance from six perspectives: business value, operational excellence, customer value, website interface, management, maintenance, and learning and innovation. Next, we usedformula-based approach to identify what makes website performance low by developing the evaluation formula through investigating website users; finally, case studies of two famous websites are given to show how our method can be used Our evaluation model can not only evaluate website performance but also suggest how to improve performance.

• 한국IT서비스학회지
• /
• 제8권2호
• /
• pp.173-187
• /
• 2009

CASE tools are complex software products offering many different features. Systems professionals have evaluated various CASE products from a feature and attribute basis. Each product has a different mix of strengths and weaknesses as perceived by the end user. Specific CASE tools support different steps of the applications development process as well as varying methodologies. In this paper we develop a method for evaluating CASE tools. The model has an analytic hierarchy process for evaluating CASE tools in terms of functionality, management efficiency, and support ability of provider, and a data envelopment analysis for overall evaluation considering cost and AHP results. We applied the developed model to a real world case study.

• 품질경영학회지
• /
• 제27권1호
• /
• pp.59-79
• /
• 1999

The fitting of a response surface model and the subsequent exploration of the response surface are usually based on the assumption that the experimental runs are carried out under homogeneous conditions. This, however, may be quite often difficult to achieve in many experiments. To control such an extraneous source of variation, the response surface design should be arranged in several blocks within which homogeneity of conditions can be maintained. In this case, when fitting a response surface model, the least squares estimates of the model's parameters and the prediction variance will generally depend on how the response surface design is blocked. That is, the choice of a blocking arrangement for a response surface design can have a considerable effect on estimating the mean response and on the size of the prediction variance. In this paper, we propose a measure for evaluating the effect of blocking of response surface designs using cuboidal regions.

• 대한교통학회지
• /
• 제7권2호
• /
• pp.17-27
• /
• 1989

A nonlinear programming model for evaluating public transit fare system is proposed. The model finds transit fare level and the structure that maximizes gross fare-box revenue subject to constraints on minimum ridership and the form of the fare equations. It is assumed that the demand for transit is a function of fare and its own-fare elasticity. It is assumed that the demand for transit is a function of fare and its own-fare elasticity. It is also assumed that the conditions including fare of the other modes are unchanged ; i.e., partial equilibrium. Empirical study has been performed for the case of Seoul subway system. This study includes an analysis of fare structure ; flat system and distance-based fare system. Sensitivity and comperative static analysis for elasticity has been also demonstrated.

• The Journal of Asian Finance, Economics and Business
• /
• 제7권5호
• /
• pp.217-224
• /
• 2020

This study investigates the impact levels of determinants on the Balanced Scorecard application in evaluating the performance of tourism firms in Hanoi. The tourism industry not only promotes economic development, but also contributes to expanding cultural exchanges and improving people's knowledge. However, Vietnam's tourism industry is under fierce competitive pressure, with the participation of foreign enterprises, with large amount of capital, high professionalism and wide network. The rivalry is happening aggressively on many aspects such as products and human resources. Therefore, tourism firms are in urgent needs of having effective methods to evaluate its performance in order to improve business and development efficiency. This study uses data of tourism firms in Hanoi during 2018-2019. The data used for analysis and regression consists of 135 observations. We use Cronbach's Alpha, EFA and regression model to learn the effect of different variables on the Balanced scorecard application in evaluating the performance. The results show that two determinants, including internal factors of tourism firms (IF) and external factors of tourism firms (EF) had positive relationships with the Balanced scorecard application in evaluating the performance. Based on the findings, recommendations are given for improving the Balanced scorecard application in evaluating the performance of tourism firms in Hanoi.

• Clinical and Experimental Reproductive Medicine
• /
• 제47권2호
• /
• pp.85-93
• /
• 2020

The implantation process is highly complex and difficult to mimic in vitro, and a reliable experimental model of implantation has yet to be established. Many researchers have used embryo transfer (ET) to assess implantation potential; however, ET with pseudopregnant mice requires expert surgical skills and numerous sacrificial animals. To overcome those economic and ethical problems, several researchers have tried to use outgrowth models to evaluate the implantation potential of embryos. Many previous studies, as well as our experiments, have found significant correlations between blastocyst outgrowth in vitro and implantation in utero by ET. This review proposes the blastocyst outgrowth model as a possible alternative to animal experimentation involving ET in utero. In particular, the outgrowth model might be a cost- and time-effective alternative method to ET for evaluating the effectiveness of culture conditions or treatments. An advanced outgrowth model and further culture of outgrowth embryos could provide a subtle research model of peri- and postimplantation development, excluding maternal effects, and thereby could facilitate progress in assisted reproductive technologies. Recently, we found that outgrowth embryos secreted extracellular vesicles containing specific microRNAs. The function of microRNAs from outgrowth embryos should be elucidated in further researches.

• Geomechanics and Engineering
• /
• 제36권3호
• /
• pp.277-293
• /
• 2024

Shored Mechanically Stabilized Earth (SMSE) walls are types of soil retaining structures that increase soil stability under static and dynamic loads. The damage caused by an earthquake can be determined by evaluating the probabilistic seismic response of SMSE walls. This study aimed to assess the seismic performance of SMSE walls and provide fragility curves for evaluating failure levels. The generated fragility curves can help to improve the seismic performance of these walls through assessing and controlling variables like backfill surface settlement, lateral deformation of facing, and permanent relocation of the wall. A parametric study was performed based on a non-linear elastoplastic constitutive model known as the hardening soil model with small-strain stiffness, HSsmall. The analyses were conducted using PLAXIS 2D, a Finite Element Method (FEM) program, under plane-strain conditions to study the effect of the number of geogrid layers and the axial stiffness of geogrids on the performance of SMSE walls. In this study, three areas of damage (minor, moderate, and severe) were observed and, in all cases, the wall has not completely entered the stage of destruction. For the base model (Model A), at the highest ground acceleration coefficient (1 g), in the moderate damage state, the fragility probability was 76%. These values were 62%, and 54%, respectively, by increasing the number of geogrids (Model B) and increasing the geogrid stiffness (Model C). Meanwhile, the fragility values were 99%, 98%, and 97%, respectively in the case of minor damage. Notably, the probability of complete destruction was zero percent in all models.