Strict Service Research Articles

CORROSION FATIGUE OF NUCLEAR--GRADE STAINLESS STEEL IN HIGH TEMPERATURE WATER AND ITS ENVIRONMENTAL FATIGUE DESIGN MODEL

The high safety of light water reactor nuclear power plants (NPPs) requires very strict design standard and service property of pressure boundary components materials. The service degradation and life assessment of the components materials primarily depend on the understanding of environmentally assisted failure mechanism, accumulation of service property data and construction of evaluation models. Currently domestic NPPs are relying on foreign design, operation and life assess- ment standards. However, recent experimental data indicate that even the ASME design fatigue code may be deficient in safety margin under certain conditions of loading and environment. In the present work, based on the corrosion fatigue tests in simulated NPPs' high temperature pressurized water, the corrosion fatigue behavior and environmentally assisted failure mechanism of domestic nuclear-grade stainless steel have been investigated. The factors affecting fatigue life of nuclear grade stainless steel in high temperature water were evaluated. A design fatigue model was constructed by taking envi- ronmental degradation effects into account and the corresponding design curves were given for the convenience of engineering applications.

모바일 인터넷 전화 서비스의 예방적 서비스 품질 관리 체계 구축을 위한 품질 측정 소프트웨어 개발 및 신뢰성 검증

Although a mobile Internet telephony service becomes popular with the rapid propagation of smart phones, its service quality management system has not been prepared enough yet. For successful settlement and deployment of the mobile Internet telephony service in future, a strict service quality management is required. The service quality management using a specific measurement equipment has limitations that real-time monitoring is impossible. In this paper, therefore, we propose a proactive service quality management system for the mobile Internet telephony service and develop a software for its implementation. The developed software is verified by comparing the measurement results from the developed software to those from the softwares commonly used, and it is proved that the developed software is quite reliable.

Sorry for your loss, now when will we be paid? Customer service after death of a customer

PurposeThe purpose of this paper is to explore how retail organizations serve heirs attempting to settle estates, suggesting that companies providing minimal customer service risk driving away future business, while those companies that seek solutions to ease the estate settlement process can acquire new customer relationships from heirs and beneficiaries.Design/methodology/approachThe paper provides examples of companies that adhere to strict rules, minimal service, or emphasis on cost reduction, comparing them to companies with more flexible and compassionate approaches to estate settlement.FindingsAn approach to customer service centered on meeting customer needs can enhance an organization's reputation. By contrast, those reliant on rigid policies risk losing long‐term business opportunities.Practical implicationsCompanies can gain new customer relationships by improving the way they handle estate claims and provide service to executors, administrators, heirs, and beneficiaries. Financial services companies in particular stand to acquire new customer relationships from the forecasted large generational wealth transfer.Originality/valueThe paper provides guidance for improving customer service when settling estates, and argues that companies that do not seek positive ways to ease the difficulties in dealing with financial matters at death ignore the basic directives of a marketing perspective.

Analysis of manufacturing blocking systems with Network Calculus

In this paper, the manufacturing blocking system (MBS) is studied from the Network Calculus (NetCal) perspective. By dominating an MBS by a window flow controller (WFC), we obtain service curves for systems with instantaneous and non-instantaneous acknowledgements. The explicit expression for the system service curve leads to the optimal allocation of the buffer sizes, which guarantees the ideal system service curve: that is, the service curve for the system with no restrictions on the sizes of in-between buffers. This allocation is more efficient than one based on guarantees of individual service curves. In addition, a method of simulation of NetCal systems is developed exploiting the duality between arrival curves and strict service curves. Simulation experiments are conducted to show the tightness of the theoretical bounds obtained using NetCal.

American, Asian and third‐party international warehouse operations in Europe

PurposeThis paper aims to report a survey carried out among European distribution centres (EDCs) in The Netherlands. EDCs are forerunners in implementing advanced logistics systems, since they are responsible for the distribution of a manufacturer's products to customers in a larger part of Europe, Middle East and Africa, often with strict service level agreements.Design/methodology/approachWarehouses with different outsourcing relations (own‐account, dedicated outsourced and public outsourced) are compared on operational aspects, performance, and future developments. Moreover, within the group of own‐account warehouses, especially Asian and American operations are tested for differences.FindingsOutsourced warehouse operations appear to have a higher percentage of error‐free deliveries and to be more flexible than own‐account operations. Based on the literature it was expected that a difference in productivity and quality between American and Asian EDCs would be found. Some differences in operations are found. For example, Asian EDCs put more effort in quality methods and involve more native managers. However, significant differences in productivity and quality levels were not found. Apparently, the differences in operations do not have a substantial effect on the warehouse performance.Originality/valueThis paper is a first attempt to compare advanced warehouse operations from different origins, either operated by service providers or not.

Sliding contention window (SCW): towards backoff range-based service differentiation over IEEE 802.11 wireless lan networks

A number of works have tried to adjust the contention window in order to provide differentiated quality of service in IEEE 802.11-based wireless networks. By giving different service classes different CWs, the distribution of backoff intervals (chosen randomly, on the interval [O, CW]) will reflect the desired service classes. However, these protocols cannot deliver firm service guarantees while maintaining high network utilization, particularly under congested network conditions. In this article we propose a new MAC protocol featuring a sliding CW (SCW) for each network flow. The SCW dynamically adjusts to changing network conditions, but remains within a per-class predefined range in order to maintain a separation between different service classes. Each flow's SCW reacts based on the degree to which class-defined QoS metrics are satisfied. Simulation results show that compared to the enhanced distributed coordination function (EDCF) scheme of 802.11e, SCW consistently excels, in terms of network utilization, strict service separation, and service-level fairness.

Anatomy of delay performance for the strict priority scheduling scheme in multi-service Internet

Strict priority scheme is one of several ways for the implementation of a service differentiation in a router because of simplicity in implementation and its capability to guarantee the delay requirement of the highest-class of traffic. It is also known that strict priority to highest-priority class traffic starves the lower-classes traffic at the cost of prioritizing the highest-class traffic. Starvation of lower-class traffic may be problematic in case the offered load of highest-class traffic is high. However, under some proper mixing of the traffic and over a high-speed link, the concerns for the starvation problem may not be so serious. In addition, we argue that delay of the highest-class traffic can be influenced by the behaviors of the lower-class traffic even under the strict priority service scheme. The purpose of this work is to present an analytic method which can represent the delay performance of the strict priority scheme in an explicit manner from those two viewpoints, and shows that it may be applied to a service differentiation scheme for the future IP network with low or moderate level of the highest-class traffic. Via numerical experiments we validate our argument.

External service provision in telecommunications networks using open interfaces

The strict service provision model used in telecommunications is following new technological trends. The service provision architectures and the services characteristics of the Next Generation Networks are altered. Telecommunications networks can become open, allowing third parties to use their resources. This creates the prospect for the rapid and flexible provision of highly personalized services. Moreover, the business model is expanded, allowing members of the Information Technology society to enter into the telecommunication market. Considering the state of the art in the service provision architectures and the specifications of standardized open interfaces; we describe how existing telecommunication infrastructure can open its functionality to third party vendors in a secure and unified way. In addition, we propose an architectural object model for the implementation of advanced applications by external parties.