Performance evaluation of a distributed concurrency control algorithm

Concurrency control (CC) algorithms are important in distributed database systems to ensure consistency of the database. A number of such algorithms are available in the literature. The issue of performance evaluation of these algorithms has been recognized to be important. However, only a few studies have been carried out towards this. This paper deals with the performance evaluation of a CC algorithm proposed by Rosenkrantz et al. through a detailed simulation study. In doing so, the algorithm has been modified so that it can, within itself, take care of the redundancy in the database. The influences of various system parameters and the transaction profile on the response time and on the degree of conflict are considered. The entire study has been carried out using the programming language SIMULA on a DEC-1090 system.

Management of thermal performance risks in buildings subject to climate change

This article reports on the use of building performance simulation to quantify the risks that climate change poses to the thermal performance of buildings, and to their critical functions. Through a number of case studies the article demonstrates that any prediction of the probable thermal building performance on the long timeframes inherent in climate change comes with very large uncertainties. The same cases are used to illustrate that assessing the consequences of predicted change is problematic, since the functions that the building provides in themselves often are a moving target. The article concludes that quantification of the risks posed by climate change is possible, but only with many restrictions. Further research that is needed to move to more effective discussion about risk acceptance and risk abatement for specific buildings is identified. © 2012 Elsevier Ltd.

Reflexive and critical views of leadership performance in corporate accomplishment : framework and illustration

Purpose – This paper intends to shed some light on the relationship between leadership performance and corporate accomplishment through the aid of complexity sciences. The objective is to describe leadership performance in corporate accomplishment using different teleological approaches.

Design/methodology/approach – The paper discusses the underlying criteria of the relationship between leadership performance and corporate accomplishment. Case illustration and narrative analogy are also provided.

Findings – The authors believe that the discussion highlights a potential downside of leadership performance in corporate accomplishment and its precision rarely highlighted in practice and literature.

Research limitations/implications – There is a reigning assumption in management practice that is based on the belief that a top-down approach of leadership performance in management and business practices is superior to the bottom-up approach. It proffers the assumed importance of strategic management issues, but neglects the knowledge, experience, competence and awareness inherent among employees at tactical and operational levels of business practices. It also proffers a mechanical view of employee performance and ignores the worth of the generation of ideas from subordinates in management and business practices that contribute to corporate achievements. Furthermore, it neglects the fact that it is not possible to know the future nor it is predictable.

Practical implications – The paper contends that the importance of top management tends to be inflated in respect to corporate achievements in the management/leadership literature. It also contends that it should be questioned as to whether the top management of corporations are largely responsible for the corporate results on which they attempt to justify their salaries and other benefits. Furthermore, the paper contends that it also should be questioned as to what extent corporate accomplishment may be derived from the performance of the top management in organizations.

Originality/value – The paper strives to contribute to the ongoing discussion of leadership performance in corporate accomplishment in various ways. The principal contributions are: a set of teleological sub-processes of leadership performance and a case illustration and narrative analogies of teleological leadership performance patterns, in respect to corporate accomplishment in management and business practices. These contributions provide theoretical and managerial ideas and insights to anticipate and avoid deficient or erroneous grounds of leadership performance evaluation in corporate accomplishment.

Strategic facilities management system in relation with building performance; the significance and relationship

Healthcare design frequently involves complex concepts that are difficult to measure and evaluate because the building require a modern, quality, functional and therapeutic environment. For this specific reason, facilities management has become a very important support system to ensure smoothness in healthcare business. Facilities management in healthcare building is a complicated system involving multiple layers of administrative division and sub-divisions. Building performance such as building impact, function and quality prove to have significant impact on strategic facilities management. This paper will do an extensive review of strategic healthcare business management as a holistic approach and examine how facilities management can effectively manage their division with consideration and understanding of building performance. The correlation between strategic facilities management and building performance will be identified and a framework for strategic FM system with regards to building performance will be developed.

Optimizing the Performance Evaluation Process for Non-Academic Staff

If conducted poorly and without support from all employee levels, performance management programs at institutions may devolve into annual evaluations that represent a staff burden rather than an ongoing career development opportunity. This brief analyzes the key components of successful performance evaluation systems for non-academic staff, incorporating insights from employers outside of the higher education sector as well. It examines the importance of midyear check-in meetings; employee goal-setting; simplified rating scales on evaluation forms; and core staff competencies that reflect institutional priorities. It also describes how institutions communicate modifications to the evaluation system and offers recommendations for the implementation of process change.

Using negotiated budgets for planning and performance evaluation: An experimental study : an experimental study

Budgets are often simultaneously used for the conflicting purposes of planning and performance evaluation. While economic theory suggests that firms should use separate budgets for conflicting purposes this contrasts with existing evidence that firms rarely do so. We address two open questions related to these observations in an experiment. Specifically, we investigate how a planning task that is in conflict with the performance evaluation task affects behavior in budget negotiations and their outcomes. Additionally, we analyze whether a single budget can be effectively used for both purposes compared to two separate budgets. We develop theory to predict that adding a planning task that is in conflict with the superior’s performance evaluation task increases the subordinate’s cooperation in and after the negotiation of a performance evaluation budget. Moreover, we predict that subordinate cooperation increases even more when the superior is restricted to use a single budget for both purposes. Our results broadly support our hypotheses. Specifically, we find that when budgets are used for both planning and performance evaluation, this increases the subordinate’s budget proposals during the negotiation and his performance after the negotiation. These effects tend to be even larger when the superior is restricted to a single budget rather than separate budgets for planning and performance evaluation, particularly with respect to subordinate performance. In our experimental setting, the benefits of increased subordinate cooperation even more than offset the loss in flexibility from the superior’s restriction to a single budget. The results of this study add to the understanding of the interdependencies of conflicting budgeting purposes and contribute to explain why firms often use a single budget for multiple purposes.

Üzleti teljesítménymérés a sportban = Business performance evaluation in sports associations

A sportszervezetek, sportvállalkozások esetében is kulcsfontosságú a teljesítménymérés. Annak ellenére, hogy a teljesítménymérés sok esetben elsősorban a sportteljesítményre koncentrál, egyre többen foglalkoznak az üzleti teljesítménymérés relevanciájával is. A nyugati társadalmakban a szűkös erőforrások és a növekvő társadalmi kontroll igénye erősíti ezt a folyamatot. A szakirodalom ezen a téren még viszonylag szűk körű. Jelen tanulmány célja, hogy egy olyan szakirodalmi áttekintést adjon, ami elindíthatja a jelenlegi és potenciális jövőbeli vezetők gondolkodását az üzleti teljesítménymérés fontosságának irányába. A tanulmány először áttekinti a pénzügyi teljesítménymérés lehetőségeit, foglalkozik a költségfelosztás problémakörével, kiemelt szerepet szán a stratégiai gondolkodás és a több szempontú megközelítés érvényesítésének. Részletesen összehasonlítja a sportszervezeteknél javasolt kiegyensúlyozott stratégiai mutatószámrendszer (BSC) adaptációkat. A tanulmány kiinduló pontot jelenthet nemcsak a szakirodalom feldolgozásához, de a gyakorlati megvalósításhoz is. _____ Performance measurement is crucial in sports associations. Although sports performance is in the spotlight, more and more researchers and experts deal with the business perspective of performance evaluation. This trend is strengthened by the scarcity of resources and a rising demand for social control in Western societies. The literature in this field is relatively limited. The aim of this study is to provide a literature review, which can motivate experts and managers to shift towards business thinking, and realize the importance of business performance evaluation. The study presents the opportunities of financial performance measurement, deals with the issues of cost allocation, and focuses on the role of strategic thinking and multi-dimension approach. Finally it compares the proposed balanced scorecard adaptations for sports associations. The study can be a starting point for literature review as well as for practical implementation.

A discussion of the research performance evaluation in building and construction management discipline : the journal impact factors and SCI-index journals

The trend of diminished funding, demands for greater efficiency and higher public accountability have led to a rapid expansion of interest in the bibliometric assessment of research performance of universities. A pilot research is conducted to provide a preliminary overview of the research performance of the building and construction schools or departments through the analysis of bibliometric indicators including the journal impact factor (JIF) published by Institute for Scientific Information (ISI). The suitability of bibliometric evaluation approaches as a measure of research quality in building and construction management research field is discussed.

Performance evaluation of an integrated solar water heater as an option for building energy conservation

Since a majority of residential and industrial building hot water needs are around 50 degrees C, an integrated solar water heater could provide a bulk source that blends collection and storage into one unit. This paper describes the design, construction and performance test results of one such water-heating device. The test unit has an absorber area of 1.3 m(2) and can hold 1701 of water, of which extractable volume per day is 1001. Its performance was evaluated under various typical operating conditions. Every morning at about 7:00 a.m., 1001 of hot water were drawn from the sump and replaced with cold water from the mains. Although, during most of the days, the peak temperatures of water obtained are between 50 and 60 degrees C, the next morning temperatures were lower at 45-50 degrees C. Daytime collection efficiencies of about 60% and overall efficiencies of about 40% were obtained. Tests were conducted with and without stratification. Night radiation losses were reduced by use of a screen insulation.

Evaluation of functional performance in commercial buildings

This report fully summarises a project designed to enhance commercial real estate performance within both operational and investment contexts through the development of a model aimed at supporting improved decision-making. The model is based on a risk adjusted discounted cash flow, providing a valuable toolkit for building managers, owners, and potential investors for evaluating individual building performance in terms of financial, social and environmental criteria over the complete life-cycle of the asset. The ‘triple bottom line’ approach to the evaluation of commercial property has much significance for the administrators of public property portfolios in particular. It also has applications more generally for the wider real estate industry given that the advent of ‘green’ construction requires new methods for evaluating both new and existing building stocks. The research is unique in that it focuses on the accuracy of the input variables required for the model. These key variables were largely determined by market-based research and an extensive literature review, and have been fine-tuned with extensive testing. In essence, the project has considered probability-based risk analysis techniques that required market-based assessment. The projections listed in the partner engineers’ building audit reports of the four case study buildings were fed into the property evaluation model developed by the research team. The results are strongly consistent with previously existing, less robust evaluation techniques. And importantly, this model pioneers an approach for taking full account of the triple bottom line, establishing a benchmark for related research to follow. The project’s industry partners expressed a high degree of satisfaction with the project outcomes at a recent demonstration seminar. The project in its existing form has not been geared towards commercial applications but it is anticipated that QDPW and other industry partners will benefit greatly by using this tool for the performance evaluation of property assets. The project met the objectives of the original proposal as well as all the specified milestones. The project has been completed within budget and on time. This research project has achieved the objective by establishing research foci on the model structure, the key input variable identification, the drivers of the relevant property markets, the determinants of the key variables (Research Engine no.1), the examination of risk measurement, the incorporation of risk simulation exercises (Research Engine no.2), the importance of both environmental and social factors and, finally the impact of the triple bottom line measures on the asset (Research Engine no. 3).

Performance evaluation of onsite wastewater treatment : field sampling and preliminary evaluation of results

Background The onsite treatment of sewage and effluent disposal within the premises is widely prevalent in rural and urban fringe areas due to the general unavailability of reticulated wastewater collection systems. Despite the seemingly low technology of the systems, failure is common and in many cases leading to adverse public health and environmental consequences. Therefore it is important that careful consideration is given to the design and location of onsite sewage treatment systems. It requires an understanding of the factors that influence treatment performance. The use of subsurface effluent absorption systems is the most common form of effluent disposal for onsite sewage treatment and particularly for septic tanks. Additionally in the case of septic tanks, a subsurface disposal system is generally an integral component of the sewage treatment process. Therefore location specific factors will play a key role in this context. The project The primary aims of the research project are: • to relate treatment performance of onsite sewage treatment systems to soil conditions at site; • to identify important areas where there is currently a lack of relevant research knowledge and is in need of further investigation. These tasks were undertaken with the objective of facilitating the development of performance based planning and management strategies for onsite sewage treatment. The primary focus of the research project has been on septic tanks. Therefore by implication the investigation has been confined to subsurface soil absorption systems. The design and treatment processes taking place within the septic tank chamber itself did not form a part of the investigation. In the evaluation to be undertaken, the treatment performance of soil absorption systems will be related to the physico-chemical characteristics of the soil. Five broad categories of soil types have been considered for this purpose. The number of systems investigated was based on the proportionate area of urban development within the Brisbane region located on each soil types. In the initial phase of the investigation, though the majority of the systems evaluated were septic tanks, a small number of aerobic wastewater treatment systems (AWTS) were also included. This was primarily to compare the effluent quality of systems employing different generic treatment processes. It is important to note that the number of different types of systems investigated was relatively small. As such this does not permit a statistical analysis to be undertaken of the results obtained. This is an important issue considering the large number of parameters that can influence treatment performance and their wide variability. The report This report is the second in a series of three reports focussing on the performance evaluation of onsite treatment of sewage. The research project was initiated at the request of the Brisbane City Council. The work undertaken included site investigation and testing of sewage effluent and soil samples taken at distances of 1 and 3 m from the effluent disposal area. The project component discussed in the current report formed the basis for the more detailed investigation undertaken subsequently. The outcomes from the initial studies have been discussed, which enabled the identification of factors to be investigated further. Primarily, this report contains the results of the field monitoring program, the initial analysis undertaken and preliminary conclusions. Field study and outcomes Initially commencing with a list of 252 locations in 17 different suburbs, a total of 22 sites in 21 different locations were monitored. These sites were selected based on predetermined criteria. To obtain house owner agreement to participate in the monitoring study was not an easy task. Six of these sites had to be abandoned subsequently due to various reasons. The remaining sites included eight septic systems with subsurface effluent disposal and treating blackwater or combined black and greywater, two sites treating greywater only and six sites with AWTS. In addition to collecting effluent and soil samples from each site, a detailed field investigation including a series of house owner interviews were also undertaken. Significant observations were made during the field investigations. In addition to site specific observations, the general observations include the following: • Most house owners are unaware of the need for regular maintenance. Sludge removal has not been undertaken in any of the septic tanks monitored. Even in the case of aerated wastewater treatment systems, the regular inspections by the supplier is confined only to the treatment system and does not include the effluent disposal system. This is not a satisfactory situation as the investigations revealed. • In the case of separate greywater systems, only one site had a suitably functioning disposal arrangement. The general practice is to employ a garden hose to siphon the greywater for use in surface irrigation of the garden. • In most sites, the soil profile showed significant lateral percolation of effluent. As such, the flow of effluent to surface water bodies is a distinct possibility. • The need to investigate the subsurface condition to a depth greater than what is required for the standard percolation test was clearly evident. On occasion, seemingly permeable soil was found to have an underlying impermeable soil layer or vice versa. The important outcomes from the testing program include the following: • Though effluent treatment is influenced by the physico-chemical characteristics of the soil, it was not possible to distinguish between the treatment performance of different soil types. This leads to the hypothesis that effluent renovation is significantly influenced by the combination of various physico-chemical parameters rather than single parameters. This would make the processes involved strongly site specific. • Generally the improvement in effluent quality appears to take place only within the initial 1 m of travel and without any appreciable improvement thereafter. This relates only to the degree of improvement obtained and does not imply that this quality is satisfactory. This calls into question the value of adopting setback distances from sensitive water bodies. • Use of AWTS for sewage treatment may provide effluent of higher quality suitable for surface disposal. However on the whole, after a 1-3 m of travel through the subsurface, it was not possible to distinguish any significant differences in quality between those originating from septic tanks and AWTS. • In comparison with effluent quality from a conventional wastewater treatment plant, most systems were found to perform satisfactorily with regards to Total Nitrogen. The success rate was much lower in the case of faecal coliforms. However it is important to note that five of the systems exhibited problems with regards to effluent disposal, resulting in surface flow. This could lead to possible contamination of surface water courses. • The ratio of TDS to EC is about 0.42 whilst the optimum recommended value for use of treated effluent for irrigation should be about 0.64. This would mean a higher salt content in the effluent than what is advisable for use in irrigation. A consequence of this would be the accumulation of salts to a concentration harmful to crops or the landscape unless adequate leaching is present. These relatively high EC values are present even in the case of AWTS where surface irrigation of effluent is being undertaken. However it is important to note that this is not an artefact of the treatment process but rather an indication of the quality of the wastewater generated in the household. This clearly indicates the need for further research to evaluate the suitability of various soil types for the surface irrigation of effluent where the TDS/EC ratio is less than 0.64. • Effluent percolating through the subsurface absorption field may travel in the form of dilute pulses. As such the effluent will move through the soil profile forming fronts of elevated parameter levels. • The downward flow of effluent and leaching of the soil profile is evident in the case of podsolic, lithosol and kransozem soils. Lateral flow of effluent is evident in the case of prairie soils. Gleyed podsolic soils indicate poor drainage and ponding of effluent. In the current phase of the research project, a number of chemical indicators such as EC, pH and chloride concentration were employed as indicators to investigate the extent of effluent flow and to understand how soil renovates effluent. The soil profile, especially texture, structure and moisture regime was examined more in an engineering sense to determine the effect of movement of water into and through the soil. However it is not only the physical characteristics, but the chemical characteristics of the soil also play a key role in the effluent renovation process. Therefore in order to understand the complex processes taking place in a subsurface effluent disposal area, it is important that the identified influential parameters are evaluated using soil chemical concepts. Consequently the primary focus of the next phase of the research project will be to identify linkages between various important parameters. The research thus envisaged will help to develop robust criteria for evaluating the performance of subsurface disposal systems.

Performance evaluation of wall mounted convector for pre-heating naturally ventilated spaces

This paper presents the results of performance monitoring under real winter weather conditions, controlled laboratory testing and computational fluid dynamics (CFD) analysis of a wall mounted ventilation air inlet heat convector. For real winter weather monitoring, the wall-mounted convector was installed in a laboratory room of the Engineering Building of the School of Construction Management and Engineering. Air and hot water temperatures and air speeds were measured at the entrance to the convector and in the room. The hot water temperature was controlled at 40, 60 and 80 °C. The monitoring results were later used as boundary conditions for a CFD simulation to investigate the air movement in the room. Controlled laboratory testing was conducted in laboratories at the University of Reading, UK and at Wetterstad Consultancy, Sweden. The results of the performance investigation showed that the system contributed greatly to the room heating, particularly at a water temperature of 80 °C. Also adequate fresh air was supplied to the room. Such a system is able to provide an energy efficient method of eliminating problems associated with cold winter draughts.

Reliability in the whole life cycle of building systems

Purpose – The purpose of this research is to show that reliability analysis and its implementation will lead to an improved whole life performance of the building systems, and hence their life cycle costs (LCC). Design/methodology/approach – This paper analyses reliability impacts on the whole life cycle of building systems, and reviews the up-to-date approaches adopted in UK construction, based on questionnaires designed to investigate the use of reliability within the industry. Findings – Approaches to reliability design and maintainability design have been introduced from the operating environment level, system structural level and component level, and a scheduled maintenance logic tree is modified based on the model developed by Pride. Different stages of the whole life cycle of building services systems, reliability-associated factors should be considered to ensure the system's whole life performance. It is suggested that data analysis should be applied in reliability design, maintainability design, and maintenance policy development. Originality/value – The paper presents important factors in different stages of the whole life cycle of the systems, and reliability and maintainability design approaches which can be helpful for building services system designers. The survey from the questionnaires provides the designers with understanding of key impacting factors.

Economic experiments used for the evaluation of building users’ energy-saving behavior

Different treatments that could be implemented in the home environ-ment are evaluated with the objective of reaching a more rational and efficient use of energy. We consider that a detailed knowledge of energy-consuming behaviour is paramount for the development and implementation of new technologies, services and even policies that could result in more rational energy use. The proposed evaluation methodology is based on the development of economic experiments implemented in an experimental economics laboratory, where the behaviour of individuals when making decisions related to energy use in the domestic environment can be tested.