• Earthquakes and Structures
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• 제9권4호
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• pp.911-936
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• 2015

This work evaluates the performance of a number of seismic assessment procedures when applied to a case study reinforced concrete (RC) wall building. The performance of each procedure is evaluated through its ability to accurately predict deformation demands, specifically, roof displacement, inter-storey drift ratio and wall curvatures are considered as the key engineering demand parameters. The different procedures include Direct Displacement-Based Assessment, nonlinear static analysis and nonlinear dynamic analysis. For the latter two approaches both lumped and distributed plasticity modelling are examined. To thoroughly test the different approaches the case study building is considered in different configurations to include the effects of unequal length walls and plan asymmetry. Recommendations are made as to which methods are suited to different scenarios, in particular focusing on the balance that needs to be made between accurate prediction of engineering demand parameters and the time and expertise required to undertake the different procedures. All methods are shown to have certain merits, but at the same time a number of the procedures are shown to have areas requiring further development. This work also highlights a number of key aspects related to the seismic response of RC wall buildings that may significantly impact the results of an assessment. These include the influence of higher-mode effects and variations in spectral shape with ductility demands.

• Journal of Korean Neurosurgical Society
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• 제61권5호
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• pp.645-652
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• 2018

Objective : This study aimed to investigate the rates, types, and risk factors of surgical site infection (SSI) following intracranial neurosurgical procedures evaluated by a Korean SSI surveillance system. Methods : This was a prospective observational study of patients who underwent neurosurgical procedures at 29 hospitals in South Korea from January 2017 to June 2017. The procedures included craniectomy, craniotomy, cranioplasty, burr hole, and ventriculoperitoneal shunt. Univariate and multivariate logistic regression analyses were performed. Results : Of the 1576 cases included, 30 showed infection, for an overall SSI rate of 1.9%. Organ/space infection was the most common, found in 21 out of the 30 cases (70%). Staphylococcus aureus was the most common (41%) of all bacteria, and Serratia marcescens (12%) was the most common among gram-negative bacteria. In univariate analyses, the p-values for age, preoperative hospital stay duration, and over T-hour were <0.2. In a multivariate analysis of these variables, only preoperative hospital stay was significantly associated with the incidence of SSI (p<0.001), whereas age and over T-hour showed a tendency to increase the risk of SSI (p=0.09 and 0.06). Conclusion : Surveillance systems play important roles in the accurate analysis of SSI. The incidence of SSI after neurosurgical procedures assessed by a national surveillance system was 1.9%. Future studies will provide clinically useful results for SSI when data are accumulated.

• Structural Engineering and Mechanics
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• 제51권3호
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• pp.433-446
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• 2014

The purpose of the research presented in this paper was to investigate the effectiveness of several conventional, multi-modal and adaptive pushover procedures. In particular, an extensive numerical study was performed considering eight RC frames characterized by a variable number of storeys and different properties in terms of regularity in elevation. The results of pushover analyses were compared with those of nonlinear dynamic analyses, which were carried out considering different earthquake records and increasing values of earthquake intensity. The study was performed with reference to base shear-top displacement curves and to different storey response parameters. The obtained results allowed a direct comparison between the pushover procedures, which in general were able to give a fairly good estimate of seismic demand with a tendency to better results for lower frames. The advanced procedures, in particular the multi-modal pushover, provided an improvement of the results, more evident for the irregular frames.

• 간호행정학회지
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• 제13권2호
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• pp.199-207
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• 2007

Purpose: Clinical characteristics and medical cost were analyzed according to the surgical procedures for intertrochanteric fracture in aged patients to assess the appropriateness of treatment expense and to find possibility of reducing the medical cost. Method: Variable for the statistical analysis were; the clinical characteristics, medical cost according to the surgical procedures, the treatment success rate, the total medical expense, and the average expense per case. SAS Package Version 8.02. was used to analyze the relevant data. Results: Operative procedures differ significantly according to the gender and by the location of institution. Only significant clinical variables according to the operative procedure were duration of general anesthesia and amount of blood transfusion. Average cost per treatment was the highest in the bipolar hemiarthroplasty followed by the gamma nail and hip compressing screw. Average cost for bipolar hemiarthroplasty was significantly higher than other surgical procedures. Conclusions: The difference in hospital costs for treatment of intertrochanteric fracture originates from the utilized surgical procedures, mostly by the materials used. The method of surgical treatment should be carefully determined by the purpose of the surgery, in order to improve the quality of medical care and also to reduce the hospital cost.

• 한국자동차공학회논문집
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• 제11권4호
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• pp.144-150
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• 2003

Recently, the virtual test techniques using computer simulation play an important part in the vehicle development procedures in order to reduce the development time and cost by replacing the physical prototypes of the vehicle components or systems with the virtual prototypes. In this paper, virtual durability test procedures for the vehicle suspension module have been developed. Virtual durability test consists of dynamic simulation computing load history of suspension components, fatigue analysis computing the life of components. A vehicle suspension module for dynamic simulation are developed and validated by comparison with the measured data obtained from the field vehicle test. And on the basis of the validated vehicle suspension model, fatigue analysis has been performed for the virtual durability design of the suspension components.

• 경영과학
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• 제17권2호
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• pp.13-20
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• 2000

In this research, we compare and analyze the two initial basis construction procedures: LPAKO’s procedure proposed by Seo et. al. and symbolic crash procedure proposed by Maros et. al.. Based on the analysis, we present a new procedure which complements the previous procedures. The new procedure shows superiority to the previous procedures with respects to the optimality of initial basis. Also, the linear basis Also. the initial basis constructed by the new procedure reduces the number of simplex iterations.

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2003년도 춘계학술대회
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• pp.135-144
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• 2003

A data set having missing observations is often completed by using imputed values. In this paper, performances and accuracy of five imputation procedures are evaluated when missing values exist only on the response variable in the exponential regression model. Our simulation results show that adjusted exponential regression imputation procedure can be well used to compensate for missing data, in particular, compared to other imputation procedures. An illustrative example using real data is provided.

• 한국통계학회:학술대회논문집
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• 한국통계학회 2001년도 추계학술발표회 논문집
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• pp.143-148
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• 2001

A dataset having missing observations is often completed by using imputed values. In this paper the performances and accuracy of complete case methods and four imputation procedures are evaluated when missing values exist only on the response variables in the Weibull regression model. Our simulation results show that compared to other imputation procedures, in particular, hotdeck and Weibull regression imputation procedure can be well used to compensate for missing data. In addition an illustrative real data is given.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.387-392
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• 2004

There has been an increasing demand for the noise impact assessment by the high-speed trains due to the expansion of high-speed rails. This paper provides procedures for the evaluation and the assessment of the potential noise impact resulting from proposed high-speed rails. Firstly the official specifications for the railway noise have been reviewed, and the procedures for the initial noise evaluation and the detailed noise analysis have been described.

• Biomaterials and Biomechanics in Bioengineering
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• 제2권4호
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• pp.207-223
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• 2015

In this paper a method for simultaneous swift non-linear analysis and optimal design/posture of mechanical/biomechanical systems is presented. The method is developed to get advantages of iterations in non-linear analysis and/or generations in genetic algorithm (GA) for the purpose of efficient analysis within the optimal design/posture. The method is applicable for both size and geometry optimizations wherein material and geometry non-linearity are present. In addition to established mechanical systems, the method can solve biomechanical models of human musculoskeletal system. Optimization-based procedures are popular methods for resolving the redundancy at joints wherein the number of unknown muscle forces is far more than the number of equilibrium equations. These procedures involve optimization of a cost function(s) which is assumed to be consistent with the central nervous system's strategy when activating muscles to assure equilibrium. However, because of the complexity of biomechanical problems (i.e., due to non-linear biomaterial, large deformation, redundancy of the problem and so on) efficient analysis are required within optimization procedures as suggested in this paper.