Usage Count Research Articles

Biodiesel Synthesis from Styrax Tonkinensis Catalyzed by S<sub>2</sub>O<sub>8</sub><sup>2-</sup>/ZrO<sub>2</sub>-TiO<sub>2</sub>-Fe<sub>3</sub>O<sub>4</sub>

The preparation of biodiesel from Styrax Tonkinensis catalyzed by solid acid S2O82-/ZrO2-TiO2-Fe3O4 at an autoclave was studied in this paper. The magnetic catalysts were characterized by XRD, which explained the high catalytic effect. At the same time, the recovery rate and usage count of catalysts were also studied. And the results showed that a high yield of transesterification can be obtained in a closed autoclave at the condition of catalyst amount 5 %, reaction time 1.5 h, reaction temperature 373K and methanol and oil molar ratio 10:1. The results also showed that the catalysts were still with a higher catalytic efficiency when the catalysts were calcinated after the forth usage.

Research on an Access Control Model for Radio and Television Monitoring Software Based on T-RBAC

With the rapid development of radio and television industry, the use of software to improve the security of broadcasting and TV system by monitoring the radio and television equipment is becoming widely adopted, So how to improve the authorization management model of software to meet the need of detailed sub-division of authority and dynamic authorization becomes the focus of the industry and has practical significance. This paper first introduces the design concept, module composition of the radio and television integrated monitoring and management system (RTIMMS). In the second place, this paper reviews advantages and disadvantages of the most frequently used models including Role-Based Access Control (RBAC) and Task Based Access Control (TBAC). By researching and comparing two models above, the paper presents a mixed model called (T-RBAC) and divides tasks in two categories and related events respectively. The process of authority management is based upon the tasks, rules in rule base and usage count of permission. The diagram of T-RBAC authorization model is also introduced in the end.

Durability of imaging plates in clinical use

In many X-ray clinics, the traditional photographic film has been replaced by an imaging plate (IP). The IP is re-usable and the purpose of this study was to test if image deterioration occurred after successive uses of the IP. The emphasis is placed on the efficiency of image formation and on image uniformity. In a cross-sectional study, 21 clinically used IPs were exposed with a standardized phantom imaging protocol. These IPs were in clinical use between one month and two years and the IPs were exposed between 191 and 3787 times. After digitizing, the mean pixel value (MPV) in a predefined image area was determined. The relation between MPV and IP uses was assessed. In a second experiment, image uniformity of 30 other clinically used IPs was visually inspected for artifacts on a diagnostic monitor. These IPs were in clinical use between one week and two years and exposed between 76 and 5373 times. The first experiment showed that no significant deterioration of the MPV with increasing usage count of the IP was present ( p = 0.15). The second experiment showed the appearance of clinically relevant artifacts on the IP before 3000 uses. It was concluded that the efficiency of the image formation process does not significantly deteriorate after successive use of IPs and is therefore not expected to limit their life span. Mechanical handling in the digitizer of the used system seems to set a limit to IP durability. Uniformity should therefore be checked regularly in clinical quality control.

Collection Development and a Long-Term Periodical Use Study: Methodology and Implications

This article describes how data on periodical use statistics, collected since 1998, were gathered and stored at Hunter Library, Western Carolina University, Cullowhee, North Carolina. It considers the significance of the data and its use for collection development purposes. Since Hunter Library does not circulate periodicals, the data collection is based on reshelving statistics using INNOPAC (the shared integrated library catalog). The data gathered, such as subscription price, bibliographic information, and usage count, were moved into a Microsoft Access database and then used to create a wide range of reports. Over the period of the study (1998–2000) there was an overall decrease in the use of periodicals that accelerated in the course of the study, many titles were used intermittently, and a large number of titles had remarkably low usage. Serials Review 2002; 28:38–44.

Collection Development and a Long-Term Periodical Use Study: Methodology and Implications

This article describes how data on periodical use statistics, collected since 1998, were gathered and stored at Hunter Library, Western Carolina University, Cullowhee, North Carolina. It considers the significance of the data and its use for collection development purposes. Since Hunter Library does not circulate periodicals, the data collection is based on reshelving statistics using INNOPAC (the shared integrated library catalog). The data gathered, such as subscription price, bibliographic information, and usage count, were moved into a Microsoft Access database and then used to create a wide range of reports. Over the period of the study (1998–2000) there was an overall decrease in the use of periodicals that accelerated in the course of the study, many titles were used intermittently, and a large number of titles had remarkably low usage. Serials Review 2002; 28:38–44.

Register allocation via usage counts

This paper introduces the notion of usage counts, shows how usage counts can be developed by algorithms that eliminate redundant computations, and describes how usage counts can provide the basis for register allocation. The paper compares register allocation based on usage counts to other commonly used register allocation techniques, and presents evidence which shows that the usage count technique is significantly better than these other techniques.