• Communications for Statistical Applications and Methods
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• v.24 no.6
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• pp.561-581
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• 2017

Bayesian statistics can play a key role in the design and analysis of clinical trials and this has been demonstrated for medical device trials. By 1995 Bayesian statistics had been well developed and the revolution in computing powers and Markov chain Monte Carlo development made calculation of posterior distributions within computational reach. The Food and Drug Administration (FDA) initiative of Bayesian statistics in medical device clinical trials, which began almost 20 years ago, is reviewed in detail along with some of the key decisions that were made along the way. Both Bayesian hierarchical modeling using data from previous studies and Bayesian adaptive designs, usually with a non-informative prior, are discussed. The leveraging of prior study data has been accomplished through Bayesian hierarchical modeling. An enormous advantage of Bayesian adaptive designs is achieved when it is accompanied by modeling of the primary endpoint to produce the predictive posterior distribution. Simulations are crucial to providing the operating characteristics of the Bayesian design, especially for a complex adaptive design. The 2010 FDA Bayesian guidance for medical device trials addressed both approaches as well as exchangeability, Type I error, and sample size. Treatment response adaptive randomization using the famous extracorporeal membrane oxygenation example is discussed. An interesting real example of a Bayesian analysis using a failed trial with an interesting subgroup as prior information is presented. The implications of the likelihood principle are considered. A recent exciting area using Bayesian hierarchical modeling has been the pediatric extrapolation using adult data in clinical trials. Historical control information from previous trials is an underused area that lends itself easily to Bayesian methods. The future including recent trends, decision theoretic trials, Bayesian benefit-risk, virtual patients, and the appalling lack of penetration of Bayesian clinical trials in the medical literature are discussed.

• The Journal of Bigdata
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• v.5 no.1
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• pp.125-138
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• 2020

After the spread of COVID-19 in 2020, the country's Crisis Alert Level went up to the highest level, Level 4. Respond of COVID-19 pandemic, Governments, and cities secured each province's duty for the citizens. The government provided health assistance first and stepped forward to support the necessary resources for the citizens. Busan City proposed policy response to prepare and implement the Corona support for each county as well. The high occupant rate of self-business owners lost basic incomes, and the effect varies on industries. In our paper, to avoid any crisis in such an epidemic, we propose a clustering analysis for the guidance of policy support for Busan City. By analyzing patterns and clustering on districts and Sectors, we would like to provide reference materials for determining the direction of support and guiding preemptive response in the event of a similar epidemic.

• Journal of the Society of Disaster Information
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• v.13 no.4
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• pp.422-441
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• 2017

Notifying emergency evacuation methods, accurate disaster location and evacuation route guidance can be very active alternatives to quickly minimize evacuation and casualties in disaster situation in the development of subway disaster prevention detection system that detects the disaster signs at the subway station early on the basis of Internet of things and leads passengers to evacuate. It's not easy to ensure perfect functioning of fire fighting facilities and equipments due to underground space structure with narrow exits. Therefore, we developed disaster provision EL Display integrated board that can induce the most efficient evacuation and the field experiment was conducted to examine the practical application in this study. Especially the applicability was verified by field application test because there is no case in which EL panels are used to evacuate disasters.

• Journal of the Korean Society of Industry Convergence
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• v.21 no.5
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• pp.247-255
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• 2018

In this research, the effect of normal load, sliding velocity, and texture density on thefriction coefficient of surfaces micro-textured on AISI 4140 under paraffin oil lubrication were investigated. The predicted tribological behavior by numerical calculation can be serves as guidance for the designer during the machine development stage. Therefore, in this research friction coefficient prediction model based on response surface methodology (RSM), support vector machine (SVM), and artificial neural network (ANN) were developed. The experimental result shows that the variation of load, speed and texture density were influence the friction coefficient. The RSM, ANN and SVM model was successfully developed based on the experimental data. The ANN model can effectively predict the tribological characteristics of micro-textured AISI 4140 in paraffin oil lubrication condition compare to RSM and SVM.

• International Journal of High-Rise Buildings
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• v.11 no.4
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• pp.347-362
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• 2022

Current vibration serviceability assessment criteria for wind-induced vibrations in tall buildings are based largely on human 'perception' thresholds which are shown not to be directly translatable to human 'acceptability' of vibrations. There is also a considerable debate about both the metrics and criteria for vibration acceptability, such as frequency of occurrence or peak vs mean vibration, and how these might vary with the nature of the vibration. Furthermore, the design criteria are necessarily simplified for ease of application so cannot account for a range of environmental, situational and human factors that may enhance or diminish the impact of vibrations on serviceability. The dual-site VSimulators facility was created specifically to provide an experimental platform to address gaps in understanding of human response to building vibration. This paper considers how VSimulators can be used to inform general design guidance and support design of specific buildings for habitability, in terms of vibration, which allow engineers and clients to make informed decisions with regard to sustainable design, in terms of energy and financial cost. This paper first provides a brief overview of current vibration serviceability assessment guidelines, and the current understanding and limitations of occupants' acceptability of wind-induced motion in tall buildings. It then describes how the dual-site VSimulators facility at the Universities of Bath and Exeter can be used to assess the effects of motion and environment on human comfort, wellbeing and productivity with examples of how the facility capabilities have been used to provide new, human experience based experimental research approaches.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.187-192
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• 2023

A problem user in a library refers to a person who harasses others or causes a disturbance through inappropriate behavior in the library. Users' continued problematic behavior reduces the work productivity of librarians and at the same time causes inconvenience to other users. This may cause a decline in the free use of public libraries. In Korea, a user response manual has been developed to guide librarians to respond wisely to user problem behavior. However, it is true that most of the content provides guidance on how to communicate with problem users, and there is a lack of countermeasures to stipulate and regulate follow-up measures against them. The goal of this study is to further systematize response and organize them into written regulations. To this end, this study to examine regulations and legal battles surrounding problem users in oversea public libraries and to examine what can be applied in Korea in the future.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.15-33
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• 2023

The liver imaging reporting and data system (LI-RADS) has been developed with the support of the American College of Radiology to standardize the diagnosis and evaluation of treatment response of hepatocellular carcinoma (HCC). The CT/MRI LI-RADS version 2018 has been incorporated in the American Association for the Study of Liver Diseases guidance. This review examines the effect of CT/MRI LI-RADS on the standardized reporting of liver imaging, and the evidence in diagnosing HCC and evaluating treatment response after locoregional treatment using CT/MRI LI-RADS. The results are compared with other HCC diagnosis guidelines, and future directions are described.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.531-536
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• 2003

In this paper, a redesigned guidance and control system for a lunar lander is presented. In past studies, the authors developed a trajectory and attitude control system which achieves the vertical soft landing on the lunar surface. It is confirmed that the system has a good tracking ability to a predefined profile and good robustness against a thruster failure mode where a partial failure of clustered engines was assumed. However, under the previous control laws, the landing point tends to be shifted, in response to the system parameter values, from a target point. Also, an unbalanced moment due to a thruster failure mode was not considered in the simulation. Therefore, in this study, the downrange control is added to the system to enable the vehicle to land at a pre-assigned target point accurately. Furthermore, inhibiting the effect of the unbalanced moment is attempted thorough redesigning the attitude control system. A numerical simulation was performed to confirm the ability of the proposed system with regard to the above problems. Moreover, in the past simulations, a low initial altitude was assumed as an initial condition: in this study, however, the performance of the proposed system is examined over the whole trajectory from an initial altitude of 10 [km] to the lunar surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.9
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• pp.821-827
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• 2007

The nitrogen oxides, NO and $NO_2$, abbreviated usually as NOx, emitted from combustion facilities such as power plants and automobiles are the typical air-pollutants causing acid rain and photochemical smog. In order to solve the NOx-related pollution problems effectively, we need efficient techniques to monitor NOx in the combustion exhausts and in environments. Development of solid-state electrochemical devices for detecting NOx is demonstrated based on various combination of solid electrolytes and auxiliary sensing materials. The object of this research is to develop various sensor performance for solid state amperometric sensor, and to test gas sensor performance manufactured. So we try to present a guidance for developing amperometric gas sensor. We concentrated on development of manufacturing process and performance test. Amperometric Nitrogen dioxide sensor was fabricated using NASICON and an $NaNO_2$ layer deposited on the counter electrode. The current response was almost linear with Nitrogen dioxide concentration in the range 1-350 ppb at $150^{\circ}C$.

• Smart Structures and Systems
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• v.21 no.1
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• pp.15-25
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• 2018

This work presents the buckling investigation of embedded orthotropic nanoplates such as graphene by employing a new refined plate theory and nonlocal small-scale effects. The elastic foundation is modeled as two-parameter Pasternak foundation. The proposed two-variable refined plate theory takes account of transverse shear influences and parabolic variation of the transverse shear strains within the thickness of the plate by introducing undetermined integral terms, hence it is unnecessary to use shear correction factors. Nonlocal governing equations for the single layered graphene sheet are obtained from the principle of virtual displacements. The proposed theory is compared with other plate theories. Analytical solutions for buckling loads are obtained for single-layered graphene sheets with isotropic and orthotropic properties. The results presented in this study may provide useful guidance for design of orthotropic graphene based nanodevices that make use of the buckling properties of orthotropic nanoplates.