浅析ORACLE系统数据库安全应用策略

通过开展ORACLE系统数据库安全理论和技术的研究是实现数据库安全的有效途径,阐述了数据库安全的研究现状,探讨了实现ORACLE系统数据库安全的策略,从而为解决ORACLE系统数据库安全提供一点借鉴。     

数据库安全研究的现状与问题

虽然经过了多年的努力，但数据库安全的理论研究和具有安全特性的数据库产品仍有令人满意。文中道德介绍了数据库安全与操作系统安全，网络安全的不同点，然后了当前数据库安全研究的几个领域，即安全数据库的语义，推理通道控制和安全的数据模型，最后提出了数据库安全研究发解决的几个问题。     

数据库安全技术研究与应用

数据库技术是应用最广泛的一门计算机技术,其安全性越来越重要。该文论述了数据库安全定义、数据库系统面临的安全威胁、数据库安全常用技术、数据安全传输常用协议及数据库安全技术研究趋势,并设计实现了高校实践教学管理系统数据库安全技术方案。     

数据库安全测评通用模型的设计与实现

针对当前数据库安全方面存在的隐患与漏洞,文章引入了数据库安全测评技术,基于该技术实现的数据库安全测评工具多为数据库安全漏洞扫描工具,并且以国家颁布的数据库安全标准为评估基准的数据库安全等级测评工具较少的情况,该文提出了数据库安全测评通用模型。文章首先给出了数据库安全的定义,介绍了国家颁布的数据库安全领域的标准,阐述了数据库安全测评技术的发展现状,给出数据库安全测评通用模型的技术要求与配置策略,进而设计了数据库安全测评通用模型,最后通过实现该模型验证了模型的可用性。     

数据库安全与安全数据库管理系统设计

过去的十几年中,许多专家学者在数据库安全领域作了大量的研究工作,取得了不少研究成果,其中有些成果已经运用到商品化的安全数据库产品中.本文首先介绍了数据库安全的重要意义和评估安全数据库的相关标准,讨论了保证数据库安全的机制,并进一步研究了实现安全数据库所应考虑的各方面问题,包括建立数据库安全模型、实施存取控制策略、数据加密、审计与攻击检测等.最后给出了几个安全数据库研究原型和产品.     

典型数据库安全分析与研究

对数据库安全的研究由来已久,尤其是到了八十年代,出于国家利益和其它原因的考虑,美国空军和国防部等单位更是大力资助这类项目,促进了数据库安全研究的发展.随着计算机和通讯技术的发展使得＂计算机网络＂的概念变得越来越广,从而使操作系统安全和数据库安全成为当今信息安全的主要课题。     

数据库安全技术研究*

对过去30多年来的数据库安全技术的研究进行了总结,并在此基础上设计出了一种安全级别至少为B1的安全数据库体系结构,展望了数据库安全研究的方向。     

数据库安全综述

数据库技术是应用最广泛的一门计算机技术，它的安全越来越重要。该文从数据库安全的定义入手，对用户认证、存取控制、安全管理和数据库加密等数据库安全技术的几个方面进行了讨论。并对国内目前采用改造数据库的方式来提高数据库安全的几个主要应用，进行了详尽的阐述，壤后指出了数据库安全现存的问题和将来研究的方向。     

典型数据库安全分析与研究

对数据库安全的研究由来已久,尤其是到了八十年代,出于国家利益和其它原因的考虑,美国空军和国防部等单位更是大力资助这类项目,促进了数据库安全研究的发展.随着计算机和通讯技术的发展使得"计算机网络"的概念变得越来越广,从而使操作系统安全和数据库安全成为当今信息安全的主要课题。     

数据库安全技术研究与应用

随着计算机技术的发展和进步,基于计算机技术的数据库安全技术也得到快速的发展,其安全性也越来越重要,因此对于数据库安全技术的研究及其应用也受到我们的高度重视。本文主要阐述数据库安全技术的研究现状及其应用情况。     

Work/rest cycles in railroad operations: effects of shorter than 24-h shift work schedules and on-call schedules on sleep

The current study examined the frequency with which shorter than 24-h work/rest cycles occur in locomotive engineer work schedules, and what effects these work/rest cycles had on sleep quantity and sleep quality. The results indicated that shorter than 24-h work/rest cycles occurred in 33.6% of the work days reported by 198 locomotive engineers. In addition, the shorter than 24-h work/rest cycles occurred more frequently in work schedules that created an on-call work system, such as road pool turn and extra board assignments, than in work schedules that used more predictable or regular work times, such as regular road assignments and yard/local work. As would be expected, when engineers worked shorter than 24-h work/rest cycles, they reported less sleep and poorer sleep than under the longer than 24-h work/rest cycles. Similarly, on-call work assignments resulted in less sleep and poorer sleep than regular work assignments. These results indicate that specific aspects of the work schedules used in railroad operations, particularly on-call operations that result in shorter than 24-h work/rest cycles, can lead to increased sleep-related problems. Although the North American railroad industry is making significant changes in on-call operations to minimize sleep-related problems from on-call schedules, better fatigue-related models validated within the railroad industry are needed.     

Work/rest cycles in railroad operations: effects of shorter than 24-h shift work schedules and on-call schedules on sleep

The current study examined the frequency with which shorter than 24-h work/rest cycles occur in locomotive engineer work schedules, and what effects these work/rest cycles had on sleep quantity and sleep quality. The results indicated that shorter than 24-h work/rest cycles occurred in 33.6% of the work days reported by 198 locomotive engineers. In addition, the shorter than 24-h work/rest cycles occurred more frequently in work schedules that created an on-call work system, such as road pool turn and extra board assignments, than in work schedules that used more predictable or regular work times, such as regular road assignments and yard/local work. As would be expected, when engineers worked shorter than 24-h work/rest cycles, they reported less sleep and poorer sleep than under the longer than 24-h work/rest cycles. Similarly, on-call work assignments resulted in less sleep and poorer sleep than regular work assignments. These results indicate that specific aspects of the work schedules used in railroad operations, particularly on-call operations that result in shorter than 24-h work/rest cycles, can lead to increased sleep-related problems. Although the North American railroad industry is making significant changes in on-call operations to minimize sleep-related problems from on-call schedules, better fatigue-related models validated within the railroad industry are needed.     

THE WORK CAPACITY OF A SYNERGIC MUSCULAR GROUP

A new conception of dynamic or static muscular work tests is presented. The authors define the critical power of a muscular work from the notions of maximum work and maximum time of work. The work capacity is then considered in the case of dynamic work, and of continuous or intermittent static work. From the data presented it is possible to define the maximum amount of work that can be performed in a given time as well as the conditions of work performed without fatigue     

Becoming a Good Homecare Practitioner: Integrating Many Kinds of Work

The paper reports from a homecare fieldwork and discusses the various types of work carried out by homecare workers. We describe formal guidelines for quality in homecare services as a background for looking deeper into the homecare practices and using them as a basis for discussing what high quality homecare is. We have identified seven types of homecare work needed in homecare: illness work, everyday life work, life-changing work, relation work, discretion work, information work and articulation work and we discuss quality in each of these as well as in the homecare as a whole. We exemplify how the quality criteria can be achieved in practice.     

A gender approach to work ability and its relationship to professional and domestic work hours among nursing personnel

The association between working hours and work ability was examined in a cross-sectional study of male (N=156) and female (N=1092) nurses in three public hospitals. Working hours were considered in terms of their professional and domestic hours per week and their combined impact; total work load. Logistic regression analysis showed a significant association between total work load and inadequate work ability index (WAI) for females only. Females reported a higher proportion of inadequate WAI, fewer professional work hours but longer domestic work hours. There were no significant differences in total work load by gender. The combination of professional and domestic work hours in females seemed to best explain their lower work ability. The findings suggest that investigations into female well-being need to consider their total work load. Our male sample may have lacked sufficient power to detect a relationship between working hours and work ability.     

OCCUPATIONAL WORK CAPACITY

For testing physical work capacity, two limits should be distinguished: maximal and occupational work capacity. Maximal work capacity is the work which yields for a few minutes the greatest oxygen-intake possible for an individual. Occupational work capacity is the highest work-level permissible in daily occupational work in kcal/min.

For young and healthy people up to about 30 years of age the occupational work capacity is about ? of the maximal work capacity. The maximal work capacity falls with increasing age until the age of 70 years when it is ? its original value. Occupational work capacity remains undiminished. The usual work capacity tests demand extremely high levels of work from the subject, e.g. step-tests, and do not determine the occupational but only the maximal work capacity. They give values far too low for the occupational work capacity of people doing little exorcise or people over 30 years of age.

The only test giving the occupational work capacity in terms of the calories which can be expended without fatigue, during occupational work, is a test measuring the rise of the pulse rate with increasing work on a bicycle-ergomotor. The author introduced this test under the name of ‘ Leistungs-Puls-Index ’ (LPI).

The normal values of maximal and occupational work capacity for male and female persons are given in kcal/min for the age range 4 to 60 years.     

Optimum schedule control of conveyer line

In the automobile industry today, various options are allowed on a single type of vehicle to meet the variety of customer tastes, and vehicles of different work specifications are carried along the same conveyer line accordingly. Since different semifinished articles on the conveyer require different work times in work zones, the work load in each work zone varies largely with the conveyer-in sequence. If the conveyer-in sequence is not proper, there is an increased risk of conveyer shutdown or an unnecessary reduction of conveyer speed and production. In this paper, the work condition of a conveyer line havingNwork zones is mathematically expressed, and the optimization of the conveyer-in sequence is shown as maximizing the minimum work allowance for all work zones and all semifinished articles. The problem is complicated, however, because the work allowance at the point of time when a semifinished article is worked on is a function of the work time and work sequence of semifinished articles in the previous work zones. Moreover, the real work is liable to be disturbed unexpectedly and requires the work schedule to be done dynamically and updated constantly so as to reflect current circumstances. A conveyer-in sequence control system which is optimum in this sense is presented together with its proofs.     

The impact of ergonomic work environment exposures on the risk of disability pension: Prospective results from DWECS/DREAM

The objectives were to identify the impact of ergonomic work environment exposures on the risk of disability pension. A representative sample of 8475 employees of the total working population in Denmark were interviewed regarding work environment exposures and followed in a national register with data on granted disability pension. For women, approximately 34% of the disability pension cases were attributable to ergonomic work environment exposures. For men, 21% of the disability pension cases were attributable to ergonomic work environment. Ergonomic work environment, especially physically demanding work, working with hands lifted and repetitive work, are areas of intervention at the workplace that can facilitate and prolong labour market participation. The study provides estimates for the association between ergonomic exposures at work and administrative, cost-related measures of work disability in a large population-based longitudinal cohort study over 14 years. Approximately 21% for men and 34% for women of the disability pension cases were attributable to ergonomic work environment exposures.     

Eyestrain in inspection and clerical workers

An attempt was made to measure eyestrain among inspection workers in highly mechanized industrial production, and to compare it with that occurring in general clerical workers. Visual functions were studied, both ocular and in the central nervous system, to clarify their patterns and their mutual relations during work. In inspection work, an improvement in accommodation was observed during the morning session. During the rest of the day accommodation was found to decrease more in inspection work than in clerical work. Visual function in the central nervous system, measured as critical flicker fusion frequency, started to decline shortly after the beginning of work and continued to deteriorate with time, both in clerical work and inspection work. In inspection work, there was an antagonistic relationship between peripheral and central visual functions in the morning session, whereas in clerical work, these two functions both deteriorated. In the afternoon session, these visual functions fluctuated considerably, and no systematic trends were seen either in inspection work or in clerical work.     

Modification of work organization

In modern Swedish industry it has been increasingly possible to reduce the dangers to health from such traditional work environmental factors as heavy lifting, loud noise, and hazardous chemicals. There has, instead, been a relative increase in the significant effects of work organization on the occurrence of injury and illness. Changes in work organization must be carried out on the basis of detailed knowledge of the work process, the tools and the product. Changes in work organization must also take into account how the personnel involved experience the way in which their needs are respected and satisfied at work. In Sweden, the work safety committees composed of representatives of all parties involved have the task not only of leading safety work, but also of channelling the needs of individual workers to influence work organization in so far as this can be of significance for their well-being and health. Company health care can analyse the common experience of a group of workers concerning their work situation in this broader context. A working method will be presented.