Target Performance Level Research Articles

Genetic-algorithm-based minimum weight design of an outrigger system for high-rise buildings

Outrigger systems, which consist of a core wall, external columns, and outriggers, are widely used in structural systems in high-rise buildings to control lateral displacements. This study proposes an optimal design method for minimizing the volume of the primary structural members (core wall, outrigger, and external columns) and calculating the optimal locations of outriggers using a genetic algorithm with the goal of efficiently controlling the lateral displacement of a high-rise building. The optimal solution of the outrigger system was determined based on the change in the number of stories (from one to four) at which outriggers were installed in a prototype model (a 400-m high-rise building). The results indicate that increasing the number of outrigger installations reduces the total volume of structural members needed in the outrigger system to satisfy the displacement constraint of the top floor (H/500, H: building height). Additionally, the cross-sections of the core wall and outrigger decreased and that of the external column increased, which indicated that the role of the external column in the control of lateral displacements increased as the number of outrigger installations increased. As a result, the contribution of the core wall to the bending moment decreased, which reduced the cross-section of the core wall. These results provide an optimal solution that considers the ideal locations of the outriggers and minimizes the volume of structural members within the maximum lateral displacement range, which is specified as a structural performance constraint. Therefore, this study can provide designers with a well-defined target performance level (e.g., lateral displacement or bending stress) during the initial stage of the outrigger system design process and an economical design that minimizes cost.

Component-level Performance-based Seismic Assessment and Design Approach for Concrete Moment Frames

To solve the conservatism of acceptance criteria in ASCE/SEI 41 provisions, a new concept of component performance is put forward and an alternative method based on the statistical distribution of component performance levels to evaluate structural performance level is proposed. Independent component performance levels are redefined in detail and component performance indicator limits are developed, which are different from acceptance criteria for integral target performance level of entire building proposed by ASCE standards. Structural components are classified into critical components and general components. The relationship between structural performance levels and the statistical distribution of component performance levels, including performance levels of critical components, general components and non-structural components, is proposed. A framework for applying this method will be discussed in detailand implemented to a seven-story moment frame. It is concluded that this new evaluation method is simple and meaningful for performance-based seismic assessment and design.

Seismic retrofit of asymmetric structures using steel plate slit dampers

A seismic design and retrofit procedure were developed for estimating the proper amount of steel plate slit dampers required to keep the seismic response of low-rise asymmetric structures within a given target performance level. Parametric studies for displacement response of a single story plan-wise asymmetric structure were conducted with varying eccentricities between center of mass and center of stiffness. Then a procedure was developed to distribute the damper based on the ductility demand of the structure. The procedure was applied to install slit dampers at proper locations of low-rise structures with horizontal and/or vertical irregularities subjected to an earthquake load. According to the nonlinear static and dynamic analysis results, the structure with hysteretic dampers installed in accordance with the proposed procedure showed satisfactory inter-story drifts in both the stiff and the flexible edges when they were subjected to the design level seismic load.

Effectiveness of Seismic Retrofit for Existing Concrete Buildings using Nonlinear Static-Analysis

In the present study, the effectiveness of the various retrofit methods for concrete structures are investigated and compared. Six methods has been presented and three most used methods; i.e. Steel Jacket, Steel Bracing and Shear Wall; are selected for further comparison and studies. The behavior of reinforced concrete structures is assessed using nonlinear static analysis and the capacities as well as demand are calculated for the target performance level. For this purpose, a weak five story concrete structure was utilized. Due to its weak design, it was recognized that the building needs re-design and retrofitting. The performances of the structure before and after retrofit by three proposed methods were compared with each other. Results of numerical Simulations show that all three retrofit methods are effective in reduction of lateral displacements, increasing of ductility and improvement of the structural capacity. However, steel bracing and shear wall are most effective for reduction of lateral displacements.

A SPATIALLY QUANTIZED POWER AND RESOURCE ASSIGNMENTS FOR CELLULAR & D2D COMMUNICATIONS

This work presents a tractable approach to enabling D2D uplink underlay in cellular networks in order to improve the spatial frequency reuse and to enhance the performance of cellular networks. In general, the cellular-to-D2D interference needs to be restricted to maintain a target performance level of the networks. In this respect, we propose an optimally quantized transmission power control and interpolation schemes for cellular users to limit the interference from them on D2D users. On the other hand, for the interference induced from D2D transmissions on the base station's receiver a concentric cell structure in conjunction with an orthogonal resource assignment scheme is developed. The proposed schemes exploit the assistance of a localization system developed to estimate the D2D and cellular user's spatial separations. Simulation results show that the proposed schemes can bring less interference and, at the same time, can easily be implemented in real cellular networks without the need of further standardization work.

정보보안기술 사용의 영향요인에 관한 실증적 연구

Although three types of the information security measures (technical, physical and managerial ones) are all together critical to maintaining information security in the organizations and should be implemented at the same time, this study aims at providing theoretical basis of establishing and implementing effective managerial security measures. The rationale behind this research objective is that it is very important to effectively perform the managerial security measures to achieve the target performance level of the technical and the physical security measures because main agents of practicing the information security measures in the organizations are staff members even though the technical and the physical ones are well constructed and implemented. In particular, this study intends to develop and propose the theoretical model applicable to providing the way of improving organizational members’ intention to use information security technologies since the very intention to use them is essential to effectively establishing and promoting managerial security measures. In order to achieve the objective of this study, the factors critical to influencing upon the intention to use information security technologies are derived through systematically reviewing related theories and previous studies, and then the research model and hypotheses are proposed by logically reasoning the casual relationship among the these factors. Also, the empirical analyses are performed by conducting the survey of the organization members of domestic large companies and analyzing the structural equation model by PLS (Partial Least Squares) method. The significant results of this study can contribute to expanding the research area of managerial information security and can be applied to suggesting the practical guidelines for effectively establishing and implementing the managerial security measures in various organizations.

Effect of Unreinforced Masonry Infill on Floor Amplification and Other Parameters in Frame-Wall Buildings

Frame-shear wall buildings or dual systems are a common form of reinforced concrete building structures. In such systems, shear walls form the primary lateral load-resisting elements intended to carry about 75% of lateral loads. The beam-column frame elements carry the vertical loads and the balance amount of lateral loads. Unreinforced masonry infill panels are common in frame-wall buildings which are incorporated to serve functional purposes. Infill panels are generally not modeled while designing the buildings. However, the influence of infill on the behavior of the building is considerable. In the present study, the response parameters in terms of average floor spectra and roof displacements have been studied in dual system buildings designed as per Unified Performance-Based Design (UPBD) method, with and without masonry infill struts. The UPBD method satisfies both target design drift and performance level simultaneously. Floor spectra are useful in the design of Operational and Functional Components (OFCs) in buildings which are mounted on floors. For the design of OFCs, parameters such as Floor Amplification factor (FAF), Component Amplification Factor (CAF), and Total Amplification Factor (TAF) are important and have been studied here. Frame-wall buildings with two plans and various heights with and without infill struts have been considered for specified target drift and performance levels. It has been observed that floor response diminishes with the incorporation of infill struts. Some important conclusions have been drawn on FEMA provisions.

Multilevel performance-based procedure applied to moderate seismic zones in Europe

The Performance-based Earthquake Engineering (PBEE) concept implies the definition of multiple target performance levels of damage which are expected to be achieved (or not exceeded), when the structure is subjected to earthquake ground motion of specified intensity. These levels are associates to different return period (RP) of earthquakes and structural behaviors quantified with adopted factors or indexes of control. In this work an 8-level PBEE study is carried out, finding different curves for control index or Engineering Demand Parameters (EDP) of levels that assess the structural behavior. The results and the curves for each index of control allow to deduce the structural behavior at an a priori unspecified RP. A general methodology is proposed that takes into account a possible optimization process in the PBEE field. Finally, an application to 8-level seismic performance assessment to structure in a Spanish seismic zone permits deducing that its behavior is deficient for high seismic levels (RP > 475 years). The application of the methodology to a low-to-moderate seismic zone case proves to be a good tool of structural seismic design, applying a more sophisticated although simple PBEE formulation.

The Role of the Tacit Knowledge in Developing the Human Resources: Critical Analytical Study of the Knowledge Centre in the Industrial Commercial Chamber in Jeddah, the Kingdom of Saudi Arabia

Abstract This paper aims mainly at identifying the role of the tacit knowledge in developing and upgrading the human resources in Jeddah chamber of commerce and industry. This is for recognizing to what extent the staff realize the use of the tacit knowledge and its characteristics, and its effect on developing the human resource and to have a proposed approach for developing and upgrading the human resources by using the entry of the tacit knowledge in Jeddah chamber of commerce and industry which can be extended to the rest of the Jeddah chamber of commerce and industry in Kingdom of Saudi Arabia. The importance of this report lies in the importance of the human resources for business organizations as it is the most important resource that is enable achieve the targeted performance levels especially in the of the competition of organizations and the continuing environmental changes. The importance of this study is represented in recognizing the role of human resources management and through its practices for supporting the learning and knowledge in the organizations, and its participation in upgrading the human resources to a level helps the business organizations to live and continue successfully. Moreover, the importance of this study is represented in shedding light on the importance of applying the practices of the human resources management apart from the traditional types of these roles and to what extent it can be applied in the chambers of commerce and industry in Kingdom of Saudi Arabia in general and Jeddah in particular. The researchers used the analytical descriptive method that relies on description and analysis in order to attain new facts leads to the increase of learning and knowledge. The study concluded that knowledge is no longer a power in the era of speed, computer and internet but the application of knowledge is the power, and that the knowledge management focuses firstly on the humans, procedures (operations) and modern techniques, and not to be arrogant and to develop what the others did, and that the knowledge builds and not creates. In the Jeddah chamber of commerce and industry the managers have to understand how to deal with the employees and to know the favourite learning techniques, and what are the motives that urge them to work seriously. Furthermore, the organizations and companies, represented in decision makers, must understand and realize that not every knowledge is important so the responsible have to concentrate on the knowledge that in their opinion participate in solving a particular problem or even making decision in addition to using it in the right way to make the organization obtain the competition opportunities and directly affect the general performance of the organization.

Performance-based Design of RC Frame Buildings with Metallic and Friction Dampers

Supplemental energy dissipation is a technique of earthquake resistant design and for improving the seismic performance of existing buildings. In the present study, a comprehensive design methodology for performance based design of frame buildings with metallic and friction dampers has been proposed. In this study, the target performance level is aimed to achieve both in terms of inter-storey drift and plastic hinge rotation. A non-iterative step-by-step design procedure is proposed to achieve the target performance level. The methodology provides the design yield forces in case of metallic dampers, and slip forces in case of friction dampers. A satisfactory distribution of both types of dampers along the height of the building is also provided in the methodology. The efficiency of the proposed design methodology is validated by applying to a ten storey building and performing nonlinear time history analysis. The building, with and without dampers, is subjected to five spectrum compatible time histories with peak ground acceleration of 0.24 g and the relative performance of the building with the two types of dampers is studied.

A Study on the Performance Simulation Model for Estimating Hardware Scale

The level of services in an information system is determined by the level of performance provided by the hardware of the system, such as the servers and the network, and the software, such as the application. Of these, the performance of the hardware is significantly affected by the specifications determined at the time of the initial implementation of the system. Therefore, when one implements a system, it should be ensured that hardware models of sufficient performance specification are selected in order to reach the targeted performance level. However, it is also apparent that high-performance hardware requires a higher investment. Therefore, from the perspective of the IT systems manager of an organization, it is important when the system is implemented to choose the hardware models that can come as close to the targeted performance level as possible within the budgetary limit. To solve this problem, organizations present instructions to calculate the appropriate scales of information system hardware. However, as these instructions are based on the capacity expected during the initial system implementation planning in the earlier stage, there are limitations in using these to establish operation plans, as deterioration in performance as the system is being operated should be anticipated. It is for this reason, in this study, that we developed an algorithm for the simulation model that can estimate the performance of the hardware not only for the initial implementation of the system but also during its operation phase.

Factors affecting the seismic behavior of segmental precast bridge columns

This manuscript discusses the design parameters that potentially affect the lateral seismic response of segmental precast post-tensioned bridge piers. The piers consist of precast circular cross section segments stacked one on top of the other with concentric tendons passing through ducts made in the segments during casting. The bottommost segments of the piers were encased in steel tubes to enhance ductility and minimize damage. An FE model was used to investigate different design parameters and how they influence the lateral force — displacement response of the piers. Design parameters investigated included the initial post-tensioning stress as a percentage of the tendon yield stress, the applied axial stresses on concrete due to post-tensioning, pier aspect ratios, construction details, steel tube thicknesses, and internal mild steel rebar added as energy dissipaters. Based on the data presented, an initial tendon stress in the range of 40%–60% of its yield stress and initial axial stress on concrete of approximately 20% of the concrete’s characteristic strength is appropriate for most typical designs. These design values will prevent tendon yielding until lateral drift angle reaches approximately 4.5%. Changing the steel tube thickness, height, or a combination of both proved to be an effective parameter that may be used to reach a target performance level at a specific seismic zone.

An Assessment Model for the Indoor Noise Environment of Aged Apartment Houses

Detached houses have been established as the traditional lifestyle of housing in Korea for thousands of years. However, apartment houses have been introduced in urban areas to meet the needs of industrialization since the 1970′s. The primary consideration of these residential structures then was the rapid construction of mass housing for urbanites rather than building performance (i.e. indoor acoustic quality). Today, residents of old, first generation apartment houses are complaining of indoor noise. This study was conducted to understand the nature of occupants′ complaints, and to investigate any gaps between residents′ expectations concerning their indoor acoustics vis-à-vis actual performance of their apartment unit. A model for assessing the indoor acoustic environment was designed, comprising of five noise elements - floor impact noise, heavy weight floor impact noise, plumbing noise, unit-to-unit sound insulation, and traffic noise level - and their target performance levels. Measurements on five elements in actual apartment houses were performed, as well as a comparison of the results based on the residents′ expectations obtained by a questionnaire survey and target levels given by the assessment model. The results have illustrated a good agreement between the measurement data and the modelled acoustic performance levels. It shows that the careful design of floor structure and plumbing systems provides a better acoustic performance for life in apartments.

Vulnerability assessment of Hassan Bey’s Mansion in Rhodes

The paper presents the vulnerability assessment of the Hassan Bey’s Mansion, located in the Medieval City of Rhodes in Greece. To this aim, the procedure developed in PERPETUATE project for the seismic assessment at scale of a single monument is adopted: it follows the performance—based concept making use of nonlinear static analyses. The main outcome of the assessment is presented in the paper in terms of maximum seismic intensity measure (the one selected as the most representative for the examined asset) compatible to various performance levels: it is used to address also the rehabilitation decisions. Within this context, the attention of this paper is focused on the use of sensitivity analysis for the identification of the main parameters that affect the structural response. Uncertainties considered in this application are both aleatory and epistemic. The epistemic uncertainties concern the effectiveness of the infilled openings: in fact, this feature strongly characterizes this building that has been subjected to many transformations along its life. Moreover, seven random variables have been considered to account for the aleatory uncertainties: they involve the material properties, the material constitutive law as well as floor rigidity. A total of 60 nonlinear static analyses have been performed for the sensitivity analysis, which represents a powerful tool for setting-up a possible investigation plan and addresses the final assessment. The resulting safety factor, computed in terms of return period, varies from 0.20 to 0.27, highlighting that the structure is not able to satisfy the target performance levels. Possible rehabilitation measures are proposed afterwards, in particular by quantitatively assessing the effect associated to the stiffening of diaphragms (very flexible in the original state).

Numerical Retrofit Study of Light-Frame Wood Buildings Using Shape Memory Alloy Devices as Seismic Response Modification Devices

Woodframe buildings have historically performed well during earthquakes primarily because of their high strength/stiffness to weight ratio. Even still, these structures possess the potential for significant damage and even collapse when exposed to very large earthquakes. New design techniques and advanced technologies can provide an alternative for improved building performance. The use of dampers and other seismic response modification devices is one such method being explored in earthquake engineering. In this paper, shape memory alloy (SMA) devices are investigated for the response modification of light-frame wood buildings during strong earthquakes. A numerical model for a suite of SMA wood shearwalls is developed based on existing data. The numerical models of the shearwalls are examined using incremental dynamic analysis at the single wall level. Design charts are developed for the shearwall models for a range of seismic weights and targeted performance levels. The wall database is then used to demonstrate retrofit of a four-story apartment building. The interstory drift was reduced by over 55% when SMA devices are used for response modification of the four-story apartment building.

DEVELOPING A FRAMEWORK FOR SUBCONTRACTOR APPRAISAL USING A BALANCED SCORECARD

Subcontractors contribute significantly to construction projects and their performance can seriously affect over-all project success. It is crucial, therefore, to appraise the performance of subcontractors to ensure they satisfy the client's expectations and project requirements. To increase the transparency and accuracy of subcontractor appraisal, the baseline and target performance levels should be set at the outset so that the appraisers and those being appraised realize exactly what standards are to be achieved. The balanced scorecard, being a powerful tool for performance appraisal, offers a potentially good approach for modeling the subcontractor appraisal process. In this paper, an approach to developing a balanced scorecard subcontractor appraisal model is proposed and demonstrated through a questionnaire survey administered in Hong Kong and from which the baseline and target performance levels for large-scale skilled subcontractors are identified. A case example is used to illustrate the operation of the model. Finally, a means by which the model may be validated is demonstrated through the use of field experts. The results demonstrate the feasibility of developing a balanced scorecard model that can help improve the transparency of subcontractor appraisal despite the baseline and target performance levels changing according to the project characteristics, subcontractor categories and size.

Effect of dietary tryptophan to lysine ratio on growth of young pigs fed wheat–barley or corn based diets

There is considerable variation in recommendations for optimum tryptophan (Trp):lysine (Lys) ratio in diets of starter pigs up to 35kg body weight (BW) which may partly be due to differences in the composition of experimental diets, the experimental approach, and the mathematical model used for data analysis. The objective of this study was therefore to determine the Trp:Lys ratio required for maximum response of pigs (15–35kg BW; BW) offered a wheat–barley–soybean meal (WB) or a corn–soybean meal (C) based diet. Three mathematical models were applied to test to which extent the choice of model will affect the estimate of optimum Trp:Lys ratio.A 4-week dose–response growth study was conducted with 880 crossbred castrated male and female pigs. The pigs were randomly allotted to eight dietary treatments per diet type. A Trp-deficient diet (T1) was formulated for each diet type that met animals׳ requirements for all amino acids other than Trp (1.4g standardized ileal digestible (SID) Trp/kg diet) and Lys (10.5g SID Lys/kg diet). L-Trp was added to T1 diets to create six additional diets per diet type (T2–T7) with SID Trp concentrations increasing from 13.1% to 19.7% in WB based and from 14.3% to 20.9% in C based diets. To test whether Lys was the second-limiting amino acid, a Lys adequate diet was formulated (T8) for each diet type by adding crystalline Lys to the respective T7 diet. Pigs had free access to feed and water. Individual BW was recorded every two weeks and pen feed intake daily.For both diet types BW gain increased (P<0.01) and feed to gain ratio improved (P<0.05) with increasing Trp:Lys ratio. In the Trp-deficient diets feed intake was reduced by 100 and 60g/day in WB and C based diets, respectively, compared to diets 2–8. According to the broken-line, curvilinear plateau, and exponential models, highest BW gain was reached at Trp:Lys ratios of 16.8%, >19.7%, and >19.7% for BW based, and 18.0%, >20.9%, and >20.9% for C based diets, respectively. The respective ratios for the feed to gain ratio were 17.0%, 18.5%, and >19.7% and 19.9%, >20.9%, and >20.9% for WB and C based diets, respectively. The results confirm published ratios determined in WB based diets and indicate a slightly higher optimum ratio in C based diets. However, the mathematical model used for data analysis, the chosen response parameter, and the target performance level strongly affect estimates of the optimum dietary Trp:Lys ratio.

Technology Transfer From Biomedical Research to Clinical Practice

Studies documented 17 years of transfer time from clinical trials to practice of care. Launched in 2002, the National Institutes of Health (NIH) translational research initiative needs to develop metrics for impact assessment. A recent White House report highlighted that research and development productivity is declining as a result of increased research spending while the new drugs output is flat. The goal of this study was to develop an expanded model of research-based innovation and performance thresholds of transfer from research to practice. Models for transfer of research to practice have been collected and reviewed. Subsequently, innovation pathways have been specified based on common characteristics. An integrated, intellectual property transfer model is described. The central but often disregarded role of research innovation disclosure is highlighted. Measures of research transfer and milestones of progress have been identified based on the Association of University Technology Managers 2012 performance reports. Numeric milestones of technology transfer are recommended at threshold (top 50%), target (top 25%), and stretch goal (top 10%) performance levels. Transfer measures and corresponding target levels include research spending to disclosure (<$1.88 million), disclosure to patents (>0.81), patents to start-up (>0.1), patents to licenses (>2.25), and average per license income (>$48,000). Several limitations of measurement are described. Academic institutions should take strategic steps to bring innovation to the center of scholarly discussions. Research on research, particularly on pathways to disclosures, is needed to improve R&D productivity. Researchers should be informed about the technology transfer performance of their institution and regulations should better support innovators.

Theoretical Investigation of Graphene Nanoribbon Field-Effect Transistors Designed for Digital Applications

Nanometer-scale, single-gate graphene nanoribbon Schottky barrier field-effect transistors (FETs) were theoretically investigated using self-consistent atomistic simulation. The device geometry was determined by referring to the International Technology Roadmap for Semiconductors. The target performance levels were the requirements specified in the roadmap for 2024, particularly a maximum leakage current of 0.1 A/m, an on-current of 2017 A/m, and a delay time of 0.13 ps. The device conditions needed to meet these requirements were found to be a bandgap larger than 1.1 eV, a supply voltage of 0.6 V, and a gate length of 7 nm.

Evaluating Dual Performance Measures on Information Dashboards: Effects of Anchoring and Presentation Format

ABSTRACTThis study examines aspects of dual performance measures in the context of organizations disclosing operational performance to the general public through information dashboards. Dual performance measures are measures where performance is a function of two values, one value denoting the percentage of a group to which the measure refers and one value denoting the performance level achieved by that particular percentage. Dual measures must be anchored to either target percentage or target performance level before a decision on over- or under-performance can be made. A 2 × 2 experiment (n = 222), involving performance assessment of a fictional emergency room, varies anchor and presentation format, and measures the effects on subjective performance of the emergency room, as well as perceived informativeness and attractiveness of the dashboard. The results indicate, first, that choice of anchor matters, in the sense that anchor choice can mask or accentuate relevant information, thereby influencing subjective performance. Second, a pictorial unit chart combined with a performance-level anchor is perceived to be the most informative and most attractive dashboard display. The study contributes to research on the design of information dashboards by developing theory on the effectiveness of reporting dual performance measures.