Utility Gain Research Articles

Prioritized Information Recovery for Wireless Link-Layer Communication

In this paper we develop Prioritized Automatic Code Embedding (PACE) link-layer protocol to achieve preferred data recovery order across connections, while maintaining stable and reliable data flows over wireless networks. We classify link-layer traffic arrivals into different priorities based on the packet delay constraint and the distortion associated with the loss of that packet. The traffic arriving in each priority class is modeled as a poisson process. Consequently, we formulate the link-layer buffer as a multiclass M/G/1 priority queuing system where the decoding process (service process) of the PACE buffer is captured by a nonhomogeneous geometric distribution. This formulation enables the determination of an optimal dynamic decoding schedule for heterogeneous link-layer traffic arrivals. PACE employs a novel rate-adaptive Low Density Parity Check (LDPC) channel code for error recovery. We model the underlying LDPC decoding process and use it to determine an optimal code selection policy for maximal bandwidth utilization. We demonstrate experimentally that PACE reduces the throughput-delay cost by 20%-70% in comparison with the IEEE802.11 ARQ and Hybrid ARQ (HARQ) protocols. Further, the PACE protocol achieves 20%-60% improvement in channel bandwidth utilization and 2-10dB PSNR gain in realtime video quality.

Time trade-off utility analysis for surgical intervention in comitant strabismus, glaucoma, and cataract.

The utility value was compared among 3 surgical interventions, and the validity of the time trade-off (TTO) method was evaluated by analyzing the correlations of the utility value with the results of the Visual Function Questionnaire-14 (VF-14) and other variables. The subjects were 127 patients aged 40-85 years who were surgically treated between January 2008 and March 2010, including 26 patients with glaucoma, 50 with cataracts, and 51 with comitant strabismus. The scores on VF-14 and utility values determined using TTO were calculated retrospectively. The mean value (SD) of the utility gain was 0.096 (0.105) for glaucoma, 0.101 (0.105) for comitant strabismus, and 0.167 (0.237) for unilateral and 0.245 (0.167) for bilateral cataracts, indicating significant postoperative improvements in the utility value. A significant correlation was observed between the utility value and the postoperative VF-14 scores of the bilateral cataracts, and the postoperative visual acuity of the better eye of the unilateral cataract. The mean value of the quality-adjusted life years was 2.181 for bilateral and 1.424 for unilateral cataracts, 1.132 for strabismus, and 0.870 for glaucoma with an annual discount rate of 3%. The gain of utility value was highest in bilateral cataracts, and lowest in glaucoma, and thus the TTO analysis was considered to be highly valid for cataract surgery.

Improving throughput in WiMAX communication at vehicular speeds

WiMAX technology has emerged as an exciting technology for next generation broadband wireless network with promises to offer high throughput and long coverage. WiMAX, however, has yet to prove its merits when the wireless nodes are not fixed and move at high vehicular speeds. Recent studies suggest that WiMAX offers limited throughput when a mobile node travels at vehicular speeds. Multipath fading causes high bit error rates at the receiver and is considered the main reason behind low throughput at high vehicular speeds. Bit error rates and maximum packet size govern the packet error rates, and error recovery for higher number of corrupted packets is not an attractive option for many real-time applications with tight delay and jitter constraints. In this paper, we present a mathematical model for estimating bit error rates in WiMAX communication at vehicular speeds. The estimated bit error probability is taken into account for proactively computing an optimum packet size that offers the best chance of achieving improved throughput. We further propose a model that can be used to increase the utility of real-time wireless applications e.g., video surveillance systems in public train based on the knowledge of estimated transmission rates. We simulated the proposed and other standard schemes for a centralized video surveillance system in a public train where the train moves at high speeds and sends real-time video data to a central control room through wireless channels. The results show that the proposed scheme achieves significantly higher throughput, lower jitter and higher utility gain compared to the standard schemes.

Urban water restrictions: Attitudes and avoidance

In most urban cities across Australia, water restrictions remain the dominant policy mechanism to restrict urban water consumption. The extensive adoption of water restrictions as a means to limit demand, over several years, means that Australian urban water prices have consistently not reflected the opportunity cost of water. Given the generally strong political support for water restrictions and the likelihood that they will persist for some time, there is value in understanding households' attitudes in this context. More specifically, identifying the welfare gains associated with avoiding urban water restrictions entirely would be a nontrivial contribution to our knowledge and offer insights into the benefits of alternative policy responses. This paper describes the results from a contingent valuation study that investigates consumers' willingness to pay to avoid urban water restrictions. Importantly, the research also investigates the influence of cognitive and exogenous dimensions on the utility gain associated with avoiding water restrictions. The results provide insights into the impact of the current policy mechanism on economic welfare.

Cost per quality-adjusted life year gained of revision neural decompression and instrumented fusion for same-level recurrent lumbar stenosis: defining the value of surgical intervention

Despite advances in technology and understanding in spinal physiology, reoperation for symptomatic same-level recurrent stenosis continues to occur. Although revision lumbar surgery is effective, attention has turned to the question of the utility and value of revision decompression and fusion procedures. To date, an analysis of cost and heath state gain associated with revision lumbar surgery for recurrent same-level lumbar stenosis has yet to be described. The authors set out to assess the 2-year comprehensive cost of revision surgery and determine its value in the treatment of same-level recurrent stenosis. Forty-two patients undergoing revision decompression and instrumented fusion for same-level recurrent stenosis-associated leg and back pain were included in this study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed. The mean (± SD) interval between prior and revision surgery was 4.16 ± 4.64 years. Bone morphogenetic protein was used in 7 cases of revision arthrodesis (16.7%). A mean cumulative 2-year gain of 0.84 QALY was observed after revision surgery. The mean total 2-year cost of revision fusion was $49,431 ± $7583 (surgery cost $21,060 ± $4459; outpatient resource utilization cost $9748 ± $5292; indirect cost $18,623 ± $9098). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $58,846. In the authors' practice, revision decompression and fusion provided a significant gain in health state utility for patients with symptomatic same-level recurrent stenosis, with a 2-year cost per QALY gained of $58,846. When indicated, revision surgery for same-level recurrent stenosis is a valuable treatment option for patients experiencing back and leg pain secondary to this disease. The authors' findings provide a value measure of surgery that can be compared with the results of future cost-per-QALY-gained studies of medical management or alternative surgical approaches.

Cost per quality-adjusted life year gained of laminectomy and extension of instrumented fusion for adjacent-segment disease: defining the value of surgical intervention

Over the past decade, there has been a dramatic increase in the number of spinal fusions performed in the US and a corresponding increase in the incidence of adjacent-segment disease (ASD). Surgical management of symptomatic ASD consists of decompression of neural elements and extension of fusion. It has been shown to have favorable long-term outcomes, but the cost-effectiveness remains unclear. In this study, the authors set out to assess the cost-effectiveness of revision surgery in the treatment of ASD over a 2-year period. Fifty patients undergoing neural decompression and extension of fusion construct for ASD-associated back and leg pain were included in the study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed. The mean (± SD) interval between prior fusion and revision surgery for ASD was 3.07 ± 2.02 years. A mean cumulative 2-year gain of 0.76 QALYs was observed after revision surgery. The mean total 2-year cost of extension of fusion constructs was $47,846 ± $32,712 (surgery cost: $24,063 ± $300; outpatient resource utilization cost: $4175 ± $3368; indirect cost: $19,607 ± $32,187). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $62,955. In the authors' practice, revision decompression and extension of fusion provided a significant gain in health state utility for patients with symptomatic ASD, with a 2-year cost per QALY gained of $62,995. When indicated, revision surgery for ASD is a valuable treatment option for patients experiencing back and leg pain secondary to ASD. The findings provide a value measure of surgery that can be compared with future cost-per-QALY-gained studies of medical management or alternative surgical approaches.

Cost-effectiveness Analysis of the Bone-Anchored Hearing Device

To establish the cost-effectiveness of a bone-anchored hearing device (BAHD). To date, there has not been any formal economic analysis of this treatment. A prospective cohort case-control analysis. Tertiary referral center, university hospital. Between April 2007 and June 2008, all adult patients undergoing their first BAHD were contacted and invited to take part in this study. Data of 70 patients were completed during the study period and were analyzed. A health utility measure was made before and after the insertion of a BAHD to estimate the utility gain associated with this intervention. The cost and quality-adjusted life year (QALY) gain for each patient was established, and an incremental cost-effectiveness ratio (ICER) was calculated. The results of our analysis are that, compared with current standard care, the BAHD has an ICER of £17,610 (US $26,415) per QALY gained. The National Institute for Health and Clinical Excellence will endorse a health intervention as cost-effective if the ICER is below £20,000 to £30,000 per QALY (US $30,000-45,000). This technology is likely to be cost-effective at the current thresholds used by National Institute for Health and Clinical Excellence. Therefore, this study suggests the BAHD may be a cost-effective method of auditory rehabilitation.

The Optimality of Tax Transfers: What does Life Satisfaction Data Tell Us?

This paper addresses an important policy question: who gets the largest utility gain from income and does the tax system adequately reflect this? We address this question by using Australian panel data and taking life satisfaction as a proxy for utility, allowing us to identify the marginal utility of additional income for different groups of individuals. We find that optimal transfers consist of transfers from the old to the middle aged, and from the married to the unmarried. This optimal utilitarian welfare policy is then contrasted with information on who actually receives transfers and who pays for them in Australia, where we find that taxes are too high for some groups, like the young, and that they are too low for other groups, like the elderly. We believe that the methodology developed in this paper could be fruitfully applied to the issue of optimal taxation in other countries.

Optimal Commodity and Cross-Currency Heding: The Case of Asean-5-Based Grain and Soft Commodity Traders

The changes in commodity prices and exchange rates leave the representative ASEAN-5-based international commodity traders exposed with multiple risks. Foreign exchange hedging ratios are simultaneously estimated alongside commodity ratios in a time-varying portfolio framework. The comparisons of the minimum variance hedge ratios (MVHR) performance reveal that the model with the time-varying variance-covariance matrix provides greater risk reduction than the conventional model, illustrating importance of time-varying variance-covariance effect when modeling joint dynamic of spot and futures returns and hence estimating hedging strategies. When transaction costs are taken into account, incorporating Student’s t significantly enhances the performance of dynamic strategies in wheat and soybeans markets. However, the conventional OLS shows superior performance in the cotton market in terms of utility gain.

Influence of Replacing Corn Grain by Enzose (Corn Dextrose) on Nutrient Utilization, Thyroid Hormones, Plasma Metabolites, and Weight Gain in Growing Lambs

The study was conducted to evaluate enzose (corn dextrose), a corn milling byproduct, as substitute for corn grain as energy in growing lambs. Five iso-caloric and iso-nitrogenous diets were formulated. The control diet (E0) had no enzose whereas enzose replaced 20, 40, 60 and 80% corn grain in E20, E40, E60 and E80 diets on the basis of energy supply, respectively. Fifty growing lambs were divided into 5 groups, 10 animals in each, in a randomized complete block design. Nutrients (dry matter, crude protein, neutral detergent fiber and acid detergent fibre) intake and digestibilities increased with gradual replacement of corn grain by enzose. Lambs fed E80 diet also retained higher nitrogen (N) than those fed E0 diet. Plasma glucose, T3 and T4 increased while urea N decreased in lambs receiving higher enzose content. Maximum weight gain was recorded in lambs fed diets containing maximum concentration of E as a replacement for corn grains. A better feed conversion ratio was recorded in lambs fed E80 compared with those fed E0 diet. The study suggests that enzose can be used as an economical feed ingredient to replace corn grain upto 80%, without any adverse effects on growth performance of growing lambs. (Key Words : Enzose, Thyroid Hormone, Biological Response, Lambs)

Utility driven optimization of real time data broadcast schedules

AbstractData dissemination in wireless environments is often accomplished by on-demand broadcasting. The time critical nature of the data requests plays an important role in scheduling these broadcasts. Most research in on-demand broadcast scheduling has focused on the timely servicing of requests so as to minimize the number of missed deadlines. However, there exists many environments where the utility of the received data is an equally important criterion as its timeliness. Missing the deadline may reduce the utility of the data but does not necessarily make it zero. In this work, we address the problem of scheduling real time data broadcasts with such soft deadlines. We investigate search based optimization techniques to develop broadcast schedulers that make explicit attempts to maximize the utility of data requests as well as service as many requests as possible within an acceptable time limit. Our analysis shows that heuristic driven methods for such problems can be improved by hybridizing them with local search algorithms. We further investigate the option of employing a dynamic optimization technique to facilitate utility gain, thereby eliminating the requirement of a heuristic in the process. An evolution strategy based stochastic hill-climber is investigated in this context.

How a luxury monopolist might benefit from the aspirational utility effect of counterfeiting?

Thanks to an intertemporal analytical model, we incorporate aspirational consumers in Veblen markets for luxury fashion items. We show how a luxury monopolist can increase its profits thanks to the presence of counterfeit products. The genuine producer profit is shaped by two opposite effects: (1) a positive aspirational effect resulting from a sales increase due to the aspirational consumers who seek to imitate the lifestyle of snob consumers (2) a negative snob effect, resulting from a sales decrease due to the reduction of consumption by some snob consumers. We identify the conditions under which the overall effect generated by counterfeiting can increase the genuine firm profit. These conditions imply the existence of large aspirational effects and high additional utility gain associated with buying an original product instead of obtaining a counterfeit product.

A WiMAX Solution For Real-Time Video Surveillance in Public Transport

Video surveillance is a highly useful tool to the public transport authorities, which is now widely used as a measure to ensure passenger safety and security. While video surveillance application in static environments like airports, shopping malls, train stations has been a huge success, real-time video surveillance in moving public transport experiences serious technological challenges mainly due to low data rates at vehicular speeds offered by existing communication technologies. Success of live video surveillance in public transport depends on future communication technologies. WiMAX has emerged as an exciting technology with promises to offer high throughput, a key requirement for video surveillance in public transport. WiMAX, however, offers limited throughput at high vehicular speeds mainly because of multipath fading that causes high bit error rate at the receiver. In this paper, we propose a forward error control (FEC) scheme for WiMAX that proactively and dynamically adjusts the size of extra parity bits of error correcting codes for real-time applications like video surveillance based on the estimated bit error probability at various vehicular speeds. We further propose a model to improve the utility gain of a live video surveillance system in public transport that uses WiMAX technology. Simulation results confirm that the proposed scheme significantly improves the throughput and utility of the video surveillance system in public transport.

An analysis of the costs and treatment success of etanercept in juvenile idiopathic arthritis: results from the Dutch Arthritis and Biologicals in Children register

To analyse and report the costs and effects of etanercept therapy in patients with JIA. Forty-nine JIA patients were evaluated by means of the JIA core set at the start of etanercept and after 3, 15 and 27 months of therapy. At the same time-points, parents of the patients were asked to complete the Health Utility Index Mark 3 (HUI3). Direct medical costs were collected for 1 year before and 27 months after the start of etanercept and compared with gain in utility. Mean total direct medical costs after the start of etanercept were on average 12 478 euros per patient-year compared with 3720 euros before start. The cost analysis showed that three-quarters of total direct medical costs were from etanercept itself. Other direct medical costs, such as costs concerning hospitalization and concomitant medication, decreased compared with the costs in the period before start of etanercept. Especially a great reduction of consultations at the outpatient clinic was seen. Utility was 0.53 before start of etanercept, according to the multi-attribute utility function of the HUI3 on a scale from 0 (dead) to 1 (perfect health). After 27 months, utility was 0.78. In accordance, also all JIA core set response variables improved significantly over 27 months of etanercept treatment. Although costs of etanercept therapy are substantial, the gain in utility is even more impressive. Considering that these JIA patients were previously refractory to conventional treatment including MTX, and were at risk of long-time disability and pain, costs are justifiable.

Mining utility-oriented association rules: An efficient approach based on profit and quantity

Association rule mining has been an area of active research in the field of knowledge discovery and numerous algorithms have been developed to this end. Of late, data mining researchers have improved upon the quality of association rule mining for business development by incorporating the influential factors like value (utility), quantity of items sold (weight) and more, for the mining of association patterns. In this paper, we propose an efficient approach based on weight factor and utility for effectual mining of significant association rules. Initially, the proposed approach makes use of the traditional Apriorialgorithm to generate a set of association rules from a database. The proposed approach exploits the anti-monotone property of the Apriori algorithm, which states that for a k-itemset to be frequent all (k-1) subsets of this itemset also have to be frequent. Subsequently, the set of association rules mined are subjected to weightage (W-gain) and utility (U-gain) constraints, and for every association rule mined, a combined utility weighted score (UW-Score) is computed. Ultimately, we determine a subset of valuable association rules based on the UW-Score computed. The experimental results demonstrate the effectiveness of the proposed approach in generating high utility association rules that can be lucratively applied for business development. Key words: Association rule mining (ARM), frequent itemset, utility, weightage, apriori, utility gain (U-gain), weighted gain (W-gain), utility factor (U-factor), utility weighted score (UW-score).

Cost effectiveness of laparoscopy versus laparotomy in early stage endometrial cancer: A randomised trial

ObjectiveTo determine the cost effectiveness of total laparoscopic hysterectomy (TLH) versus total abdominal hysterectomy (TAH) in early stage endometrial cancer alongside a multicenter randomised controlled trial (RCT). MethodsAn economic analysis was conducted in 279 patients (TLH n=185; TAH n=94) with early stage endometrial cancer from a societal perspective, including all relevant costs over a three month time horizon. Health outcomes were expressed in terms of major complication-free rate and in terms of utility based on women's response to the EQ-5D. Comparisons of costs per major complication-free patient gained and costs with utility gain and costs were made, using incremental cost effectiveness ratios. ResultsThe mean major complication-free rate and median utility scores were comparable between TLH and TAH at three months. TLH is more costly intraoperatively (Δ$1.129) and less costly postoperatively in-hospital (Δ$−1.350) compared to TAH. Incremental costs per major complication-free patient were $−52. Higher cost ($249) were generated while no gains in utility (−0.02) were observed for TLH compared to TAH. Analysing utility at six weeks, incremental costs per additional point on the EQ-5D scale were $1.617. ConclusionTLH is cost effective compared to TAH, based on major complication-free rate as measure of effect. Along with future cost saving strategies in laparoscopy, TLH is assumed to be cost effective for both effect measures. Therefore and due to comparable safety, TLH should be recommended as a standard-of-care surgical procedure in early endometrial cancer.

A Cell Model to Describe and Optimize Heat and Mass Transfer in Contact Heat Exchangers

A cell model to describe and optimize heat and mass transfer in contact heat exchangers for utilization of exhaust gases heat is proposed. The model is based on the theory of Markov chains and allows calculating heat and mass transfer at local moving force of the processes in each cell. The total process is presented as two parallel chains of cells (one for water flow and one for gas flow). The corresponding cells of the chains can exchange heat and mass, and water and gas can travel along their chains according to their transition ma-trices. The results of numerical experiments showed that the most part of heat transfer occurs due to moisture condensation from gas and the most intense heat transfer goes near the inlet of gas. Experimental validation of the model showed a good correlation between calculated and experimental data for an industrial contact heat exchanger if appropriate empirical equations were used to calculate heat and mass transfer coefficient. It was also shown that there exists the optimum height of heat exchanger that gave the maximum gain in heat energy utilization.

Designing Ranking Systems for Hotels on Travel Search Engines by Mining User-Generated and Crowd-Sourced Content

User-Generated Content (UGC) on social media platforms and product search engines is changing the way consumers shop for goods online. However, current product search engines fail to effectively leverage information created across diverse social media platforms. Moreover, current ranking algorithms in these product search engines tend to induce consumers to focus on one single product characteristic dimension (e.g., price, star rating). This approach largely ignores consumers’ multi-dimensional preferences for products. In this paper, we propose to generate a ranking system that recommends products that provide on average the best value for the consumer’s money. The key idea is that products that provide a higher surplus should be ranked higher on the screen in response to consumer queries. We use a unique dataset of U.S. hotel reservations made over a three-month period through Travelocity, which we supplement with data from various social media sources using techniques from text mining, image classification, social geo-tagging, human annotations, and geo-mapping. We propose a random coefficient hybrid structural model, taking into consideration the two sources of consumer heterogeneity the different travel occasions and different hotel characteristics introduce. Based on the estimates from the model, we infer the economic impact of various location and service characteristics of hotels. We then propose a new hotel ranking system based on the average utility gain a consumer receives from staying in a particular hotel. By doing so, we can provide customers with the “best-value hotels early on. Our user studies, using ranking comparisons from several thousand users, validates the superiority of our ranking system relative to existing systems on several travel search engines. On a broader note, this paper illustrates how social media can be mined and incorporated into a demand-estimation model in order to generate a new ranking system in product search engines. We thus highlight the tight linkages between user behavior on social media and search engines. Our inter-disciplinary approach provides several insights for using machine learning techniques in economics and marketing research.

Minority HIV mutation detection in dried blood spots indicates high specimen integrity and reveals hidden archived drug resistance

Background Dried blood spots (DBS) could serve as an attractive, cost-effective alternative to plasma for HIV drug resistance testing. Objectives To assess the utility and potential gain in genotypic information with sensitive testing of DBS compared to conventional bulk plasma genotyping, and examine the correlation of majority and minority-level resistance mutations in DBS with treatment history. Study design Evaluate nucleic acids from the DBS of 33 antiretroviral-experienced subtype B-infected subjects for minority M41L, K65R, K70R, K103N, Y181C, M184V, and T215Y/F mutations by real-time PCR. Compare minority resistance mutations in DBS with bulk genotypes from the same DBS cards and available plasma specimens. Results All but one (50/51, 98%) mutation from the original plasma bulk sequencing were still detectable in the DBS after three years of storage. The one mutation not identified in DBS was also no longer detectable by bulk sequencing. Furthermore, sensitive testing found 12 additional drug resistance mutations at minority levels in the DBS of 11 (33%) patients. Six minority mutations were in the RNA compartment and six were detected only in the DNA compartment. Resistance was detected in the DBS RNA compartment only in cases where the associated drug was in use within one year of sample collection. Conclusions Our ability to identify majority and additional minority-level resistance mutations demonstrated that DBS, if stored properly, is a high-integrity specimen type for conventional and sensitive drug resistance testing. Our data further support the global utility of DBS for drug resistance surveillance and clinical monitoring.

Response of growing buffalo calves to various energy and protein concentrations

The current study was planned to examine the response of altered dietary protein and energy concentrations on nutrients utilization, nitrogen metabolism and weight gain in growing male Nili Ravi buffalo calves to know optimum protein and energy requirements in comparison with those documented by the Nutrient Requirement for Cattle (NRC) for calves. Thirty six calves of 6–7months of age weighing (77±05kg) were divided into 6 groups, six animals in each group, according to 3×2 factorial arrangements of treatments. Six experimental diets were formulated containing three levels of crude protein (CP; 11.85, 14.20 and 16.50%) each with two levels of metabolizable energy (ME; 1.86 and 2.23 Mcal/kg). The animals were fed individually ad libitum for 100days; the first 10days was the dietary adaptation period while the last 10days of each of the remaining month served as the collection period. Daily feed consumption in calves fed all the experimental diets remained unaltered. However, the intake of fiber fractions was significant (p<0.05) among treatment groups. The digestibility of dry matter (DM) was significant (p<0.05) while neutral detergent fiber (NDF) and CP digestibilities were similar among treatment groups. However, the intake of DM, CP, ME and fiber fractions indicated significant (p<0.05) difference among treatment means with respect to protein levels. On the other hand, the intake of ME and fiber fractions was significant (p<0.05) with respect to ME levels of the diets. Similarly, digestibilities of DM and fiber fraction also showed significant (p<0.05) difference among treatment means. Weight gain, and feed conversion efficiency of buffalo calves didn't show any treatment effect. The findings of the present study suggested 14.20% and 2.24Mcal/kg ME as optimum CP and energy requirements for growing male buffalo calves with less than 1year of age.