Important Key Performance Indicators Research Articles

Monitoring online biomass with a capacitance sensor during scale-up of industrially relevant CHO cell culture fed-batch processes in single-use bioreactors

In 2004, the FDA published a guideline to implement process analytical technologies (PAT) in biopharmaceutical processes for process monitoring to gain process understanding and for the control of important process parameters. Viable cell concentration (VCC) is one of the most important key performance indicator (KPI) during mammalian cell cultivation processes. Commonly, this is measured offline. In this work, we demonstrated the comparability and scalability of linear regression models derived from online capacitance measurements. The linear regressions were used to predict the VCC and other familiar offline biomass indicators, like the viable cell volume (VCV) and the wet cell weight (WCW), in two different industrially relevant CHO cell culture processes (Process A and Process B). Therefore, different single-use bioreactor scales (50–2000 L) were used to prove feasibility and scalability of the in-line sensor integration. Coefficient of determinations of 0.79 for Process A and 0.99 for Process B for the WCW were achieved. The VCV was described with high coefficients of determination of 0.96 (Process A) and 0.98 (Process B), respectively. In agreement with other work from the literature, the VCC was only described within the exponential growth phase, but resulting in excellent coefficients of determination of 0.99 (Process A) and 0.96 (Process B), respectively. Monitoring these KPIs online using linear regression models appeared to be scale-independent, enabled deeper process understanding (e.g. here demonstrated in monitoring, the feeding profile) and showed the potential of this method for process control.

Free-Standing Carbon Electrodes for the Oxygen Evolution Reaction

N-functionalized hydrothermal carbon materials (N-HTC) with spherical morphology were prepared by hydrothermal synthesis utilizing glucose and urotropine as starting materials, which makes the synthesis cost-efficient, environmental friendly and allows simple scale-up. The molar ratio of glucose and urotropine has been varied and the powder materials were pelletized, resulting in mechanically stable disc electrodes. By increasing the amount of nitrogen, N-contents from 5 wt% up to maximal 8 wt% were obtained after pyrolysis at 1000 °C. The pellet can then be used as an anode for alkaline water splitting. In literature, there are still no direct evidence of metal-free carbon as electrocatalyst for oxygen evolution reaction. By comparing the N-functionalized sample and without functionalization, we found that the former has superior stability under water splitting condition (relative high potential). Up to one week of stable oxygen production was achieved. The result indicates that nitrogen facilitates oxygen evolution reaction. Besides, the nitrogen species also hinders carbon corrosion, proved by a simple Hoffmann cell measurement. Pellets with different synthesis condition as well as nitrogen content are compared in order to get the optimized synthesis condition. For better understanding, methylene blue adsorption and mercury intrusion porosimetry are used to characterize the pore structure of the carbon materials. The relative work function and conductivity of the carbon pellet are determined by Kelvin-probe and Van-der-Pauw methods, respectively. A conventional three-electrode assembly is used to characterize the electrochemical performance, including activity, stability as well as mass transport property by cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy (EIS). A transmission line equivalent circuit model is used to fit the EIS complex spectra, where the diffusion resistance and reaction resistance can be determined. The two resistances are very important reaction key performance indicator for oxygen evolution reaction, as it can distinguish a diffusion process from a reaction. The gas products as well as electrolyte after electrochemical test can be analysed by mass spectrometry, ESI-MS, UV-VIS spectroscopy, etc. From the mass spectrometry results, the mole fraction of oxygen in the total product gas can be determined, determining the selectivity of the reaction. Besides, water diffusion NMR measurements before and after electrochemical test shows changes in the water interaction, which can be correlated to Nitrogen species changes in the electrode. This study demonstrates that N-functionalization improves the stability of HTC for oxygen evolution reaction providing a promising pathway for the future energy conversion and storage.

Impact of international branch campus KPIs on the university competitiveness: FARE method

International branch campus is a rather new phenomenon in higher education and it is often questioned if it is an effective tool for HEI competitiveness because of its high risks and extremely high costs. In order for higher education institution managers to be able to use an international branch campus (IBC) as a tool for competitiveness, indicators of IBC having the strongest influence on the competitiveness of HEI must be indicated. In order to determine the main key performance indicators semi structured interviews were executed with the top managers of international branch campuses globally and the gathered data was analysed and coded using the computer assisted qualitative data analysis (CAQDAS) with Nvivo software. Six most important key performance indicators of IBCs have been identified and the FARE (Factor Relationship) method was used in order to determine the weights of the latter criteria. A system of indicators has been developed to assess the impact of HEI international development on the university's competitiveness and a relationship between the key performance indicators of the IBCs and the university's competitiveness has been revealed.

Application-Level Packet Loss Rate Measurement Based on Improved L-Rex Model

The current network information asymmetry is infringing the interests of end users in non-neutral network environment. To empower users, application-level performance measurements are usually used to rebalance the information asymmetry currently disfavoring users. Application-level packet loss rate, as an important key performance indicator (KPI), receives extensive attention in academia. However, every coin has its two sides. Although the application-level packet loss estimation is simple and nonintrusive, since the information available from the application layer is relatively scarce compared to the lower layers, the estimation accuracy has no guarantee. In view of this, taking the L-Rex model as the cut-in spot, this paper focuses on leveraging the self-clocking mechanism of Transmission Control Protocol (TCP) to improve the accuracy of application-level loss estimation. Meanwhile, owing to the dynamically estimated parameters and the weakened packet reordering impact, the robustness of estimation is also expected to be improved accordingly. Finally, a series of comparative experiments at the practically relevant parameter space show that the enhanced approach and strategy detailed in this paper are effective.

Contrast detection probability - Implementation and use cases

The automotive industry formed the initiative IEEE-P2020 to jointly work on key performance indicators (KPIs) that can be used to predict how well a camera system suits the use cases. A very fundamental application of cameras is to detect object contrasts for object recognition or stereo vision object matching. The most important KPI the group is working on is the contrast detection probability (CDP), a metric that describes the performance of components and systems and is independent from any assumptions about the camera model or other properties. While the theory behind CDP is already well established, we present actual measurement results and the implementation for camera tests. We also show how CDP can be used to improve low light sensitivity and dynamic range measurements.

ANALYSIS OF GSM NETWORK QUALITY OF SERVICE USING CALL SETUP FAILURE RATE AND HANDOVER FAILURE RATE INDICES

Over the decades, the Global System for Mobile (GSM) communications technology has become one of the fastest growing and most challenging telecommunications technologies. The Call Setup Failure Rate (CSFR) and Hand-Over Failure Rate (HOFR) were the most important Key Performance Indicators (KPIs) used in ascertaining the efficiency of GSM network in terms of the quality of services rendered. For customers, it is expected that maximum satisfaction is derived from any service rendered, which was not the case over the years. The increase of HOFR and poor network availabilities due to increased CSFR became a great concern to all parties (providers, users, and researchers). Hence, this paper assessed the Quality of Service (QoS) of MTN GSM network in four geographical areas (Kaduna South, Kaduna North, Zaria, and Kafanchan) using two Key Performance Indicators (KPIs) of HOFR and CSFR. The data used in the assessment was collated from MTN Network Management Center (NMC) with the aid of the FACTS tool. These KPI results were evaluated against those specified by the Nigerian Communications Commission (NCC) in order to make some important recommendations from the findings (contributions) to improve the QoS of MTN network.

Fuzzy Multi Criteria Approach for Sustainable Maintenance Evaluation in Rubber Industry

Abstract This paper proposes a fuzzy multi criteria approach for evaluating sustainable maintenance in rubber industry. A literature study is conducted to identify the key performance indicators (KPIs) and then validated by academics and industry experts. As a result, three factors of economic, social, and environmental indicators (dividing into a total of thirteen indicators) are proposed as the KPIs for sustainable maintenance evaluation in rubber industry. Next, the Interpretive Structural Modeling (ISM) method is applied to determine the interrelationships of KPIs. The results identified four indicators of environmental factor as the most influencing KPIs, while six indicators of economic factor suggested as the most influenced KPIs. Finally, the Fuzzy Analytic Network Process (FANP) method is used to determine the importance weight of KPIs. The lighting and ventilation is regarded as the most important KPIs, followed by working environment, energy consumption, and emission. The proposed evaluation model is expected to assist the rubber industry in improving their sustainable maintenance performance.

The Conceptual Design of Flexible Manufacturing System with the Use of Computer Simulation in Enterprise Dynamics

Nowadays, production processes become more and more complicated because of global market competition and the need for flexible changes in production in order to meet customer needs. That is related to the frequent reorganization of production systems and require adequate operations management, internal and external logistics, and project management from the stage of conceptual design to the industrial implementation. Currently, we may observe an increased use of automation and robotization, which replace human labor. Modern industrial robots can work similarly to a human operator, but the replacement of a human operator with a robot is related to some technical problems and excessive cost, therefore robotic workstations must be properly designed. The aim of the study is developing a method which allows estimation of productivity growth associated with the replacement of human labor with industrial robots at an early design stage. The production flow in the manufacturing system and internal logistic processes were modeled in the Enterprise Dynamics software, which enables simulation and visualization of discrete production processes. The models were built taking into account availability, performance and quality parameters, which enable a direct calculation of OEE (Overall Equipment Effectiveness) indicator, which is one of most important Key Performance Indicator (KPI) used in World Class Manufacturing (WCM) methodology, especially in automotive industry. The use of OEE indicator enables comparison with similar manufacturing systems. The example of the conceptual design of the flexible manufacturing cell, with CNC machine tools, which can be operated by humans or robots, is presented. The production process includes two machining operations of large and heavy parts, which are difficult to handle, therefore robots are preferred to apply. The computer simulation of the sophisticated model of the flexible manufacturing system with machines, operators and robots with reliability parameters allows better representation and understanding of a real production process at the stage of conceptual design. The experiment results confirm the advantage of the application of robotic operated production systems comparing to manually operated machines with production growth of about 17%. However, robotization is related to very high investment cost, therefore detailed economic analysis is required, including a comparison of labor cost and robot cost. Obtained results can be used for detailed designing of manufacturing systems and robotic workstations.

ENGAGING BRAND COMMUNICATION IN FACEBOOK – A TYPOLOGY OF THE BRAND PAGE USERS

Facebook offers great opportunities for brands to connect with customers and build relationships with them in order to increase their loyalty and the company’s sales. In regards to these goals, one of the most important key performance indicators is the customers’ activity – liking, commenting, sharing, recommending, expressing love, etc. On one hand, there is a lot of research on customers’ engagement, behavior and motivation. These studies provide valuable information for marketers to understand the way in which individuals use the social network and interact with others as well as the reasons behind their actions. Based on this knowledge they can develop their communication strategies and create content which has impact on the target audience. On the other, there are still some research gaps which can be further explored. One of them is related to the impact of one of the most important company assets – the brand culture, on the customer’s behavior and willingness to become part of the digital brand story. This paper presents a Facebook brand page users typology, developed by using a semiotic approach, which is based on their brand culture adoption and brand narrative engagement.

IDENTIFY THE KEY PERFORMANCE INDICATORS FOR BOT(BUILD-OPERATE-TRANSFER) PROJECTS IN FEASIBILITY AND BIDDING STAGES IN TURKEY

Although Public-private partnership (PPP) is a widely used project delivery system in the recent years, it is also criticized due to their low performance. Therefore, there is a need for achieving more efficient and effective PPP projects. For that purpose, the performance of the PPP projects should be managed carefully. However the performance of PPP projects is affected by various variables through the projects’ life cycle. In addition, PPP projects have their certain applications, which in turn lead to having its own features (for example intricate system of procurement, management of transfers, the regulations of the government and management of stakeholders). Therefore, the performance management models developed for traditional project delivery systems are not applicable to the PPP projects, and specific performance management models should be developed for PPP projects. Especially, performance measurement should be performed carefully. Key Performance Indicators (KPI) are very important to comprehensively evaluate PPP projects, and they should be identified prudently. In this study, the KPIs of feasibility and bidding stages of PPP projects are identified by conducting a literature survey. A questionnaire based on this literature review is prepared, and a total of 80 questionnaires were collected. These KPIs are evaluated by performing descriptive analyses. Consequently, the most important KPIs are determined as selection of appropriate PPP model and sound financial analysis at feasibility stage. For bidding stage, these are detailed tender procedure and government’s knowledge of PPP. The performance of PPP is influenced heavily by the process variables which were ignored by previous studies as their major focus was on risk management, success measurement and planning. In addressing this need, Liu et al. suggested that a phase-oriented evaluation process that accommodates key performance indicators (KPIs) in each phase of a project's life- cycle should be considered.

Day 5 useable blastocyst rate is an early indicator of clinically significant shifts in the embryo culture system

The ability to track performance of an IVF laboratory using statistical process controls has not been validated and remains an important goal for an early warning signal of shifts in laboratory conditions. The Vienna consensus report recently defined Key Performance Indicators (KPIs) for monitoring fresh IVF and ICSI cycles, but the effectiveness of these KPIs for detecting clinically relevant shifts following changes in laboratory processes is unknown1. The aim of this study was to assess whether embryology KPIs detect shifts in laboratory performance that result in changes in clinical outcomes. Retrospective, multicentre, analysis of KPIs for fresh IVF and ICSI cycles. Three consecutive 5-month periods of embryo culture media were investigated 1) embryo culture in Continuous Single Culture Complete (CSCM-C) (Irvine Scientific) 2) embryo culture in G-TL (Vitrolife) 3) embryo culture returned to CSCM-C (Irvine Scientific). Six primary embryology KPIs were tracked for 1523 cycles from June 2016 to August 2017; ICSI fertilization rate, IVF fertilization rate, useable day 5 blastocyst rate, overall useable blastocyst rate, clinical pregnancy rate and cumulative clinical pregnancy rate. Meaningful KPI shifts were identified by upper and lower warning (2-sigma) and control (3-sigma) limits. KPI shifts were analyzed by ANOVA and multivariate regression. During the 15 months analyzed, the novel KPI, useable day 5 blastocyst rate, fell below the 3-sigma lower control limit for 5 months. The decrease in useable day 5 blastocyst rate, from 43% to 32%, occurred following a change from CSCM-C (Irvine Scientific) to G-TL (Vitrolife) and was detected one week after the change (p < 0.0001). Useable day 5 blastocyst rate subsequently recovered after a change back to CSCM-C (p < 0.0001). A decrease in clinical pregnancy rate (54% to 41%) was also observed, but this was not detected until 3 months after the useable day 5 blastocyst rate shift (p = 0.01). Although culture media type independently effected useable day 5 blastocyst rate and clinical pregnancy rate, the cumulative clinical pregnancy rate was similar among the three time periods. Importantly, overall useable blastocyst rate (day 5-7) remained within control limits (52%) for all three periods, indicating that the overall rate alone may not sufficiently monitor embryology laboratory performance. This study validates a statistical KPI monitoring system to provide systematic, early detection of culture condition shifts in ART laboratories. Useable day 5 blastocyst rate is identified as an important KPI, which complements overall useable blastocyst rate (day 5-7).

Determining key performance indicators for warehouse performance measurement – a case study in construction materials warehouse

Warehouse performance measurement is needed to improve performance of logistics system. In order to improve warehouse performance, it is necessary to identify Key Performance Indicator (KPI). Different warehouses have different KPI, therefore this research aims to identify the most important KPI of warehouse so that warehouse manager can determine corrective actions in their warehouse efficiently and effectively. In this research, 25 KPI of warehouse are identified in five warehouse activities based on Frazelle model. The most important KPI are then determined in each warehouse activity using Analytical Hierarchy Process (AHP). Warehouse performance are measured and final score is determined using SNORM. Improvement steps are proposed base on benchmarking among warehouses. Warehouse performance measurement is conducted in 5 construction’s material warehouses located in Yogyakarta, Indonesia. From this study, it is found that most important KPI for receiving is productivity (receive per man-hour), KPI for put away is cycle time (put away cycle time), KPI for storage is utilization (% location and cube occupied), KPI for order picking is cycle time (order picking cycle time) and KPI for shipping is productivity (order prepared for shipment per man-hour). Improving warehouse performance could be done by comparing warehouse performance with the best performance among peer group.

Competitive Benchmarking with FM Customer and Occupant Satisfaction Surveys

ABSTRACT Customer satisfaction is arguably one of the most important key performance indicators (KPIs) in the business world. Facilities management (FM) researchers and practitioners have begun to examine this KPI and adapt it for use in facility services. Most of the adaptations have regarded internal benchmarks and use in quality management. Though research demonstrates the effectiveness of competitive benchmarking and, more specifically, the effectiveness of customer satisfaction as a competitive benchmark, there is little research on how to use customer satisfaction as a competitive benchmark in FM. Researchers have focused on determining the appropriate content for customer service surveys but have not documented how and to what extent the surveys are currently being used. To help fill this gap in the research, an industry-wide study on operations and maintenance (O&amp;M) was conducted for an FM organization in 2017. Approximately 700 respondents in the United States completed the survey, and the responses were analyzed to examine the use of customer/occupant satisfaction surveys in the nation's FM industry. The results indicate that two-thirds of the industry uses these surveys at varying frequencies; the frequency differs somewhat according to the size of the facility in Rentable Square Feet (RSF), as there is a positive linear correlation between RSF and survey frequency. Future research on the use of these surveys as a competitive benchmarking tool needs to focus on standardizing these surveys to enable more equitable comparisons and engaging in in-depth interviews to evaluate the process by which FM departments manage their occupant satisfaction for continual improvement.

Will COTS RF Front-Ends Really Cope With 5G Requirements at mmWave?

In this paper, the real-time over-the-air multi-gigabit wideband wireless orthogonal frequency division multiplexing (OFDM) system performance, using two distinct radio frequency (RF) front-ends designed for the millimetre frequency band (mmWave), is evaluated. A thorough comparative analysis between 60-GHz cutting-edge commercial off-the-shelf and reference RF front-ends, taking into account their intrinsic RF impairments and their impact on the overall system performance degradation, is presented. With this, it is possible to verify whether system on chip technology for RF circuits is ready for 5G systems. Due to the large available bandwidth, the mmWave band is very attractive for future 5G wireless communication systems, which might provide transmission data rates over 10 Gb/s and network latency below 1 ms. However, non-linearities of RF front-ends, at these frequencies, severely affect the performance of transmission schemes. In fact, this is the main cause for performance degradation on OFDM systems. It causes significant limitation on both maximum spectral efficiency and data rate of the wireless communication link. Therefore, the OFDM performance degradation due to the non-linearities from both analogue stages of upconversion/downconversion is evaluated considering important key performance indicators for quality of service in digital communications considering 4-, 16-, 64- and 256-quadrature amplitude modulation. Furthermore, based on the results obtained from appropriate RF measurements, a practical EVM link budget formulation for mmWave systems, which takes into account both PA and PN impairment effects, is proposed.

Towards 5G: Performance evaluation of 60 GHz UWB OFDM communications under both channel and RF impairments

Detailed analysis on the impact of RF and channel impairments on the performance of Ultra-Wideband (UWB) wireless Orthogonal Frequency Division Multiplexing (OFDM) systems based on the IEEE 802.15.3c standard, for high data-rate applications using the 60 GHz millimetre frequency band is presented in this paper. This frequency band, due to the large available bandwidth is very attractive for future and 5G wireless communication systems. The usage of OFDM at millimetre-wave (mmWaves) frequencies is severely affected by non-linearities of the Radio Frequency (RF) front-ends. The impact of impairments is evaluated, in terms of some of the most important key performance indicators, including spectral efficiency, power efficiency, required coding overhead and system complexity, Out-Of-Band Emissions (OOBEs), Bit Error Rate (BER) target and Peak Signal-to-Noise Ratio (PSNR). Additionally, joint distortion effects of coexisting Phase-Noise (PN), mixer IQ imbalances and Power Amplifier (PA) non-linearities, on the performance degradation of a mmWave radio transceiver, combined with various multipath fading channels, are investigated. Subsequently, the power efficiency of the system is evaluated by estimating values of the PA Output-Power-Backoff (OBO) needed to meet the requirements for the Transmit Spectrum Mask (TSM) and BER target. Finally, a comparison of the system overall performance between uncoded and coded OFDM systems combined with Quadrature Amplitude Modulations (16 and 64 QAM) and its maximum operable range are evaluated by transmitting a Full HD uncompressed video frame under five different RF impairment conditions over a typical LOS kiosk 60 GHz IEEE channel model.

When 2nd generation biofuel meets water – The water solubility and phase stability issue

Greenhouse gas emissions from the transportation sector could be reduced by using biofuels. To avoid competition with the food chain, second generation biofuels produced from lignocellulosic biomass are of major interest. The interaction of second generation biofuels and water needs to be studied since water is known to have major impacts for first generation biofuels. In this work, we explore the water solubility and phase stability for second generation biofuels from catalytic conversion of biomass. Tetrahydrofurans are potential biofuels for compression ignition engines. We find that the water solubility in tetrahydrofurans is increased by a factor 200 compared to Diesel. In furans, suitable as fuels for spark ignition engines, the water solubility is 4 orders of magnitude larger than in gasoline. In blends of biofuels, water solubility can either be increased or decreased depending on the blend component. Water can strongly influence the miscibility of biofuel-blends: adding small amounts of water to a γ-valerolactone – di-n-butyl ether blend leads to phase separation resulting in two organic phases with different combustion behavior. At the same time, the biofuels studied dissolve much better in water, which is relevant for potential environmental impacts. The phase behavior with water is thus shown to be an important key performance indicator for the development of biofuels.

Factors influencing control charts usage of operational measures

PurposeThe purpose of this paper is to identify factors influencing implementation of control charts on key performance indicators (KPIs).Design/methodology/approachFactors driving organizational change described in literature are analyzed inspired by the affinity-interrelationship method. A holistic multiple-case design is used to conduct six workshops to affect the usage of control charts on KPIs at a global company in the automotive industry. The theoretical factors are compared with the result from the case study.FindingsThe important factors for implementation success differ to some extent between the theoretical and empirical studies. High-level commitment and a clear definition of the goal of change could be most important when creating a motivation for change. Thereafter, having a dedicated change agent, choosing an important KPI and being able to describe the gain in financial terms becomes more important.Practical implicationsBy using control charts on KPIs, the organization in the case study has become more proactive, addressing the right issues upstream in the process, in the right way, cross-functionally.Originality/valueFactors affecting the implementation of already available solutions in the industry are highlighted. This potentially provides a basis for improved decision making, which has a significant value.

Life Cycle Assessment for supercritical pulverized coal power plants with post-combustion carbon capture and storage

Environmental and technical aspects of four supercritical (SC) pulverized-coal processes with post-combustion carbon capture and storage (CCS) are evaluated in the present work. The post-combustion CCS technologies (e.g. MDEA, aqueous ammonia and Calcium Looping (CaL) are compared to the benchmark case represented by the SC pulverized coal without CCS). Some important key performance indicators (e.g. net electrical power, energy conversion efficiency, carbon capture rate, specific CO2 emissions, SPECCA) are calculated based on process modeling and simulation data. The focus of the present work lies in the environmental evaluation, using the Life Cycle Analysis (LCA) methodology, of the processes considered. The system boundaries include: i) power production from coal coupled to energy efficient CCS technologies based on post-combustion capture; ii) upstream processes such as extraction and processing of coal, limestone, solvents used post-combustion CCS, as well as power plant, coal mine, CO2 pipelines construction and commissioning and iii) downstream processes: CO2 compression, transport and storage (for the CCS case) as well as power plant, CCS units, coal mine and CO2 pipelines decommissioning. GaBi6 software was used to perform a “cradle-to-grave” LCA study, to calculate and compare different impact categories, according to CML 2001 impact assessment method. All results are reported to one MWh of net energy produced in the power plant. Discussions about the most significant environmental impact categories are reported leading to the conclusions that the introduction of the CCS technologies decreases the global warming potential (GWP) indicator, but all the other environmental categories increase with respect to the benchmark case. There is also a competition between the aqueous ammonia adsorption and CaL for some impact categories (other than GWP). The implementation of these new CCS technologies is more favorable than the traditional amine-based CO2 capture.

Systematic review of the feasibility of laparoscopic reoperation for early postoperative complications following colorectal surgery

Returning to the operating theatre for management of early postoperative complications after colorectal surgery is an important key performance indicator. Laparoscopic surgery has benefits that may be useful in surgical emergencies. This study explored the evidence for the advantages of laparoscopic reoperation. A systematic review was performed to identify publications reporting the outcomes of laparoscopy as a mode of reoperation for the management of early postoperative complications of colorectal surgery. The main outcomes examined were 30-day mortality, 30-day morbidity, length of hospital stay, second reoperation rate, ICU admission and stoma formation at reoperation. After screening 3657 citations, ten non-randomized cohort studies were identified (1137 reoperations). Laparoscopic reoperation was equivalent to or better than open reoperation, with lower rates of 30-day mortality (0-4·4 versus 0-13·6 per cent), 30-day morbidity (6-40 versus 30-80 per cent), length of stay (mean(s.d.) 15·8(2·8) versus 29·1(14·5) days), ICU admission and duration of stay in the ICU. Anastomotic leak was the most common indication, after which more patients received a defunctioning loop stoma instead of an end stoma at laparoscopic than open reoperation. Laparoscopic reoperation is feasible in selected patients, with the advantages of improved short-term outcomes.

3G Wireless Network Optimization

The importance of wireless communication cannot be overlooked in this modern day of sophisticated communication world. Certainly, like any other technology, wireless communication has major challenges, most of which tremendously affect our daily conversations. This research is focused on wireless network optimization specifically on the Code Division Multiplexing Access (CDMA) technology. Emphasis will be on the importance of optimization and the various strategies adopted to optimize a wireless network. The beginning part of the research contains a comprehensive introduction of wireless optimization and specifically touched on its definition as well as the most essential aspect of its application in the wireless network. The research explicitly identified important Key performance indicators which usually monitors the performance of the wireless network. Also, in order to solve wireless network deficiencies, several approaches are used to achieve this goal. The research touched on these approaches and described how exactly they are applied to optimize a network. Wireless optimization is mainly achieved with the use of special tools such as drive test tools. As part of the research, the most important tools were identified as well as their applications. Additionally, a broad analysis was made on some common wireless issues as well as strategies adopted to resolve them. Some of the common problems identified include: handoff issues, call failure issues PN planning issues, Neighbor list planning issues as well as pilot pollution issues. Furthermore, in order to better understand the optimization in the practical sense, a case study was analyzed by comparing specific samples of results gathered before and after optimization. The results clearly demonstrated that wireless optimization improves wireless performance tremendously, which goes to attest to the fact that, the end results have a positive impact on subscribers and the composite society at large with tremendous benefits ranging from financial to great customer satisfaction.