Search results

The purpose of this paper is to introduce the theoretical basis of N-order spectral spreading-compressing (SSC) frequency shift interference algorithm and expand it to active cancellation. An active cancellation simulation and verification system based on N-order SSC algorithm is established and carried out; simultaneously, the absorbing material coating stealth simulation of two kinds of thickness is carried out to compare the stealth effect with active cancellation system.

The active cancellation method based on N-order SSC algorithm is proposed based on theoretical formula derivation; the active cancellation simulation and verification system is established in MATLAB/Simulink. The full-size model is built by CATIA and meshed by hypermesh. The omnidirectional radar cross section (RCS) is calculated in cadFEKO, and the results are analyzed in postFEKO.

The simulations are implemented on a stealth fighter, and results show that after active cancellation, the peak of spectrum analyzer has reduced in all azimuths, the omnidirectional RCS has also decreased and the detection probability of almost all azimuths has dropped under 50 per cent. The absorbing material coating stealth simulations of two kinds of thickness are carried out, and results show that the stealth effect of active cancellation is much better than absorbing material coating.

An active cancellation system based on SSC algorithm is proposed in this paper, and the effect of active cancellation is verified and compared with that of absorbing materials. A new method for the current active stealth is provided in this paper.

Active cancellation simulation and verification system is established. RCS calculation module, signal-to-noise-ratio (SNR) calculation module and detection probability module are built to verify the effect of active cancellation system. Simultaneously, the absorbing material coating stealth simulation is carried out, and the stealth effect of absorbing material coating and active cancellation are compared and analyzed.

Cancelled operations are a major drain on health resources: 8 per cent of scheduled elective operations are cancelled nationally, within 24 hours of surgery. The aim of this study is to define the extent of this problem in one Trust, and suggest strategies to reduce the cancellation rate.

A prospective survey was conducted over a 12‐month period to identify cancelled day case and in‐patient elective operations. A dedicated nurse practitioner was employed for this purpose, ensuring that the reasons for cancellation and the timing in relation to surgery were identified. The reasons for cancellation were grouped into patient‐related reasons, hospital clinical reasons and hospital non‐clinical reasons.

In total, 13,455 operations were undertaken during the research period and 1,916 (14 per cent) cancellations were recorded, of which 615 were day cases and 1,301 in‐patients: 45 per cent (n=867) of cancellations were within 24 hours of surgery; 51 per cent of cancellations were due to patient‐related reasons; 34 per cent were cancelled for non‐clinical reasons; and 15 per cent for clinical reasons. The common reasons for cancellation were inconvenient appointment (18.5 per cent), list over‐running (16 per cent), the patients thought that they were unfit for surgery (12.2 per cent) and emergencies and trauma (9.4 per cent).

This study demonstrates that 14 per cent of elective operations are cancelled, nearly half of which are within 24 hours of surgery. The cancellation rates could be significantly improved by directing resources to address patient‐related causes and hospital non‐clinical causes.

This paper is of value in that it is demonstrated that most cancellations of elective operations are due to patient‐related causes and several changes are suggested to try and limit the impact of these cancellations on elective operating lists.

This paper aims to demonstrate how hospitality management research could benefit from the propositional style of theorizing, and how this approach could expand the scope of research in the discipline.

Developing new theories could provide unique insights and broaden the scope of research in hospitality management. To illustrate the power of proposition-based theorizing, this methodology is applied to the hotel cancellation policies domain.

Using the proposition-based theorizing in the context of cancellation policies, this study provides several propositions that could have broad implications for future research.

The contribution of this paper is threefold. First, the potential benefit of the proposition-based theorizing in the revenue management context of cancellation policies is demonstrated. Second, the theoretical frameworks and insights from the product return policy literature that could enrich future studies on hotel cancellation policies are introduced. Finally, this study conjectures on these theories’ relevance to hotel cancellation policies and consequently on their potential contribution to the scholarly discourse.

The purpose of this paper is to demonstrate that process verification has matured to a level where it can be used in practice. This paper reports on new verification techniques that can be used to assess the correctness of real‐life models.

The proposed approach relies on using formal methods to determine the correctness of business processes with cancellation and OR‐joins. The paper also demonstrates how reduction rules can be used to improve the efficiency. These techniques are presented in the context of the workflow language yet another workflow language (YAWL) that provides direct support for 20 most frequently used patterns found today (including cancellation and OR‐joins). But the results also apply to other languages with these features (e.g. BPMN, EPCs, UML activity diagrams, etc.). An editor has been developed that provides diagnostic information based on the techniques presented in this paper.

The paper proposes four properties for business processes with cancellation and OR‐joins, namely: soundness, weak soundness, irreducible cancellation regions and immutable OR‐joins and develop new techniques to verify these properties. Reduction rules have been used as a means of improving the efficiency of the algorithm. The paper demonstrates the feasibility of this verification approach using a realistic and complex business process, the visa application process for general skilled migration to Australia, modelled as a YAWL workflow with cancellation regions and OR‐joins.

Business processes sometimes require complex execution interdependencies to properly complete a process. For instance, it is possible that certain activities need to be cancelled mid‐way though the process. Some parallel activities may require complex “wait and see” style synchronisation depending on a given context. These types of business processes can be found in various domains, such as application integration, B2B commerce, web service composition and workflow systems. Even though cancellation and sophisticated join structures are present in many business processes, existing verification techniques are unable to deal with such processes. Hence, this paper plays an important role in making process verification a reality.

The purpose of this study is to provide new insights into the factors that influence cancellation behaviour with respect to hotel bookings. The data are based on individual bookings drawn from a hotel reservation system database comprising nine hotels.

The determinants of cancellation probability are estimated using a probit model with cluster adjusted standard errors at the hotel level. Separate estimates are provided for rooms booked offline, through online travel agencies and through traditional travel agencies.

Evidence based on 233,000 bookings shows that the overall cancellation rate is 8 per cent. Cancellation rates are highest for online bookings (17 per cent), followed by offline bookings (12 per cent) and travel agency bookings (4 per cent). Probit estimations show that the probability of cancelling a booking is significantly higher for early bookings, large groups that book offline, offline bookings during high seasons, bookings not involving children and bookings made by guests from specific countries (e.g. China and Russia). Among the factors, booking lead time and country of residence play the largest role, particularly for online bookings.

The analysis is based on individual-level booking data from one hotel chain in Finland, and therefore cannot be generalised for the total population of hotels in the country under observation.

The main contribution of this paper is a thorough investigation of the factors that influence cancellation behaviour at both the theoretical and empirical levels. Detailed and unique data from a hotel reservation system allow for new empirical insights into this behaviour.

The purpose of this study is to investigate the decision-making process of librarians at the University of Western Ontario who attempted to cancel the Wiley Big Deal. The aim of the study is to reveal the underlying factors that affected their decision-making process. By understanding the decision-making process of librarians, it may be possible to devise a system that takes into consideration not only quantitative factors but also the subjective or qualitative factors that impact librarians’ decisions and thus make it easier to cancel these Big Deals.

The study involved administering an online survey to 25 librarians involved in the cancellation project. Follow-up interviews were conducted with 13 of these librarians to understand at a deeper and more nuanced level the factors that influenced their decisions.

The main finding was that the librarians who participated in the study could be divided into two groups – a data-driven criteria group and a subjective criteria group – based on their ranking of the factors used to make their cancellation decisions. Most librarians interviewed used a mixture of quantitative factors and qualitative factors when making their cancellation decisions. The authors found that those participants who had greater professional experience and a closer relationship with the faculties in their subject areas had more difficulty in cancelling journals. Very few librarians relied on quantitative data alone.

This study is one of few that have examined the subjective factors that influence librarians’ decisions regarding cancellation of Big Deals. It has implications regarding the movement towards centralized collection management and reliance on quantitative data alone when making collection decisions.

The insurance industry has not been able to effectively retain its customers and struggles to establish and maintain long-lasting relationships with them. The purpose of this paper is thus to identify the main factors that explain the cancellation of motor insurance policies by individual customers, considering the influence of intermediaries on their decisions.

The data used in this research is based on a sample of 3,500 insurance policies that lapsed during the period of analysis between January and July 2017, against another sample of 3,500 policies that did not lapse, from a major insurance company in Portugal. Binary logistic regression was used for data analysis, using IBM SPSS software.

Aggressive tactics by insurance companies for customer acquisition may induce the cancellation of insurance policies. More valuable customers, the policies with higher premiums and recent claims, as well as the ancillary intermediaries and agents, are determinants of insurance cancellation. Conversely, the payment of policies by direct debit and without instalments reduces the probability of cancellations.

The main limitation of this study is the restriction on data access. Insurance companies are significantly resistant to sharing their customer data – including with academic researchers – even in an anonymised form.

The paper highlights internal and external practices of insurance companies that should be reformulated to significantly improve their performance regarding product cancellation, related to customer information management, mistrust behaviours related to stakeholders and new value propositions that deepen the relationships with intermediaries.

This research developed a framework with which to identify the factors that are mainly associated with motor insurance cancellation and to predict its likelihood.

保險業一向未能有效地留住客戶，故業內不斷努力建立並維繫與客戶長久的關係。因此、本文擬確定個人客戶終止其汽車保單的因素；研究過程中、會考慮中介人對客戶作有關決定的影響 。

本研究所使用的數據、為基於一個涵蓋3500份期滿終止保單的樣本、並以之與另一涵蓋3500份沒有終止保單的樣本相比，樣本均來自葡萄牙一家大型保險公司。期滿終止保單之樣本、乃於2017年1月至同年7月這個研究進行期間内期滿終止的。研究使用了二元羅吉斯迴歸來分析數據，並應用了IBM SPSS 數據分析軟件。

保險公司為贏得客戶所採用的積極進取策略可能導致客戶終止其保單。保單終止的決定因素包括更多有價值的客戶、保險費較高的保單、最近的索賠和輔助的中介及代理。反之，以自動扣帳方式及以非分期付款形式繳付保單則會減低終止保單的機會。

本研究發展了一個框架、以確定與客戶終止其保單有關聯的主要因素，並預計客戶終止保單的可能性。本文亦強調了保險公司須重新制定其內部與外部的做法，以能大幅改善其與產品取消有關的績效，而這些產品取消涉及客戶信息管理、與持份者有關的不信任行為、以及能深化與中介人之關係的新價值主張。

To establish the reasons for surgical cancellations in a urology department and to provide suggestions for their reduction.

Data for all patients who were cancelled between September 2004 and February 2005 were collected to determine the reasons for cancellations and the number of procedures cancelled on the day of surgery.

A total of 175 procedures were cancelled in a six‐month period, comprising 14.1 per cent of all elective operations scheduled. Of these, 25.7 per cent were cancelled on the day of surgery. The main reasons for cancellations were patients being unfit for surgery (20 per cent); patient reasons for cancellations, such as the date being inconvenient (20 per cent); operations no longer being necessary (16 per cent); and the surgeon being unavailable or unable to operate (10.3 per cent).

It is believed that at least 26 per cent of all cancellations are avoidable with simple strategies such as effective communication between surgeons and booking office staff. Other methods to reduce the number of cancellations are presented.

The purpose of this paper is to explore the issues around the considerable increase in emergency calls experienced by a large county ambulance trust and implications for the implementation of government policy in relation to the English National Health Service Ambulance Service.

The paper involves a literature review and the analysis of the ambulance service data based on emergency call outs, and discussions with senior ambulance and health authority personnel.

Increased calls were mainly explained by a large increase in cancellations, especially after the vehicle had arrived at the scene. The term “cancellation” is potentially misleading and may carry connotations of wasted resources. There was little evidence of inappropriate calls and no single cause of cancellations or any simple solution. Instead, a wide range of actions were included, many of which seem potentially worthwhile. However, the way the data are presented disguises their diversity and potential value. This reflects the tension between policy and practice, and organisational culture and performance measurement regime.

This is a single case study and is limited by the parameters of the data base gathered by the ambulance service as part of their normal operational procedures.

This paper gives support to the enhanced role of the ambulance paramedic and the need to recognise this changing role through a more appropriate approach to performance measurement. The present emphasis on response times and transportations to hospital may result in undervaluing activities at the scene.

The paper identifies a key area where research into policy and governance issues has been limited and presents recommendations for future analysis.

The purpose of this paper is to find the incidence and medical reasons for cancellations of elective orthopaedic cases following admission for an operation in a district general hospital. The paper also aims to determine the deficiencies in the local preoperative assessment protocol.

This is a retrospective study. The elective orthopaedic surgeries cancelled following their admission into the hospital due to medical reasons between January 2003 and December 2004, were identified. These cases were reviewed using the preoperative assessment charts and case notes. The NHS Modernisation Agency's guidelines, National Good Practice Guidance on Preoperative Assessment for Inpatient Surgery, are taken as the benchmark for comparison.

The paper finds that 44 elective orthopaedic cases were cancelled due to medical reasons. Of these patients, 64 per cent did not have a pre‐operative assessment prior to the admission for the planned surgery; 6 per cent had inadequate documentation of relevant past medical history; and 30 per cent (patients with significant medical problems) were not referred to the anaesthetist for advice although these problems were identified during the pre‐operative assessment.

It is possible to stimulate good medical practice through audit.

Cancellation of an elective operation is not uncommon in hospital practice. This paper aims to highlight the possible avoidable causes for such cancellations. The paper identifies such deficiencies in the local preoperative assessment protocol and suggests remedies to improve the quality of care. These improvements and close adherence to the guidelines are important as preoperative assessment by nurse‐led clinics are being increasingly practised through out the UK.

The paper fulfils its aims of identifying the medical causes for cancellation of an operation and also the existing deficiencies in the preoperative assessment practice. The paper values the importance of adherence to NHS Modernising Agency's guidelines in preoperative assessment. It is useful not only to the Orthopaedic department but also to the department managers.