采用三维自适应遗传算法的高校排课问题研究

根据教师、学生、课程、教室和时间要求建立多约束数学模型,并结合遗传算法特点,对其各个步骤进行了改进,提出了基于三维自适应遗传算法的排课方法。实验结果表明,与传统排课方法相比,基于三维自适应遗传算法的排课方法能有效降低课程之间的冲突率,提高排课效率和成功率。     

遗传算法应用于排课问题中的时间表最优化

介绍由计算机根据教师的意愿,利用遗传算法自动进行排课,最大限度地满足教师的愿望,对资源作出优化合理的安排。而且,利用Excel实现排课的遗传算法。排课分为教师安排和课程时间的安排两部分。这里论述课程时间的安排。     

基于课程间关联规则的排课优化算法研究

针对如今高校招生人数扩张所伴随而来的高校排课资源紧张的现象进行了研究,提出了一种基于关联规则的排课优化算法（SH-AP算法）来优化高校排课。SH-AP算法将关联规则算法应用到排课过程中,通过对高校学生选课数据进行关联规则的挖掘,找出需要排课的课程之间的关联规则,之后SH-AP算法再将已经挖掘出的课程间关联规则应用到排课系统中,对高校排课进行优化。实验最终得到课程间关联规则的数据,并为高校提供人性化的排课。根据研究与对比表明SH-AP算法在对排课的合理化与人性化上有很好的优化效果,帮助学校在进行排课的时候,考虑课程时间地点冲突问题的同时,对学生的需求进行满足。     

基于关联规则的排课系统

排课是学校教学管理中一项重要而复杂的基本工作,其实质就是为学校所设置的课程安排一组适当的教学时间与空间,从而使整个教学活动有计划有秩序地进行。本文对排课系统进行了研究,引入关联规则算法,对排课冲突进行数据挖掘,最后得到一份合理而均衡的课表。     

基于数据库关系运算的排课算法设计

高校因其需要在固定时间内开设门类众多的课程,排课问题显得尤为突出。排课不仅是通过合理的课程安排使得学生能符合规律的学习成长,也是在探寻多因素问题的求解方式和过程。基于关系运算就排课的一般问题进行分析,包括变量的规范化界定和排课问题的理论分析,提出"分层规划"的解决方案,并采用数据库的关系运算完成排课算法的设计。该算法有效地降低了排课问题的复杂度,并满足了用户的期望和各种约束。     

基于数据库关系运算的排课算法设计

高校因其需要在固定时间内开设门类众多的课程,排课问题显得尤为突出。排课不仅是通过合理的课程安排使得学生能符合规律的学习成长,也是在探寻多因素问题的求解方式和过程。基于关系运算就排课的一般问题进行分析,包括变量的规范化界定和排课问题的理论分析,提出“分层规划”的解决方案,并采用数据库的关系运算完成排课算法的设计。该算法有效地降低了排课问题的复杂度,并满足了用户的期望和各种约束。     

高校排课系统算法的改进与实现

运用遗传算法对排课问题进行研究.按照算法思想将课程分解为课程项,在教室和时间的二维空间中进行交叉、变异,同时实现上课时间均匀、特殊约束等条件限制;设计了运算参数,给出排课算法的核心步骤伪代码.     

基于蚁群算法的高校排课问题的研究

随着高校学生规模的不断扩大,排课难度系数也随之加大,致使手动排课方式的劣势逐步显现。为提高教务排课的高效性,优化排课系统模式,解决在排课过程中教室、教师、班级、课程和时间的冲突及组合优化的问题,阐述了利用二分图模型实现资源优化分配,提出了基于蚁群算法的智能排课研究。研究结果证明,系统智能排课功能的实现,提高了排课效率,排出科学合理的人性化课表,满足了广大师生的需求。     

类遗传算法在高校排课系统中的应用

将排课问题转换成对课程项分配教室和时间的问题,采用类似遗传算法的思想,随机产生不存在硬冲突的排课方案作为染色体,以每个课程项的排课方案作为染色体的基因,通过排课软冲突构造适应度函数,计算染色体的适应度,再对染色体进行选择、变异,直到染色体的适应度达到给定值。     

高校智能排课系统算法的研究与实现

研究高校智能排课优化问题,由于在资源的有限的条件下满足教学的有序性,使高校自动排课成为一个多约束、多目标优化问题.传统排课方法排课效率低、成功率低,导致课程之间冲突率高,无法满足现代高校教务管理要求.为了提高排课效率和排课成功率,提出一种自适应遗传算法的智能排课系统.首先根据教师、学生、教室、课程和课程时间段要求建立一个多约束条件的高校排课数学模型,采用随机可行排课法操作产生可行排课方案,然后利用遗传算法在可行方案中寻找最优排课方案.仿真结果表明,相对于传统排课方法,自适应遗传算法不仅提高了排课效率,而且提高排课的成功率,有效降低课程之间冲突率,并能够解决高校排课难题.     

A New Model of Computation for Learning Vision Modules from Examples

This paper addresses an important class of mimicry problems, where the goal is to construct a computer program which is functionally equivalent to an observed behaviour. Computer vision research can be considered such a challenge, where a researcher attempts to impart human visual abilities to a computer. Unfortunately this has proved a difficult task, not least because our vision processes occur mostly at a subconscious level. It is therefore useful to study the general mimicry problem in order to develop tools which may assist computer vision research.This paper formalises a mimicry problem as one in which a computer learning system (L) constructs a solution from a given program structure (i.e. template or outline) by posing questions to an Oracle. The latter is an entity which, when given an input value, produces the corresponding output of the function which is to be mimicked.In order to define a program's structure, particularly one which can be extracted from any computer program automatically, a new model of computation is developed. Based on this a fast algorithm which determines the best questions to pose to the Oracle is then described. Thus L relieves the human programmer of the difficulties faced in choosing the examples from which to learn. This is important because a human programmer might inadvertently choose biased, redundant or otherwise unhelpful examples. Results are shown which demonstrate the utility of a complete learning system (L) based on this work.This paper represents background theory and initial algorithms which further work will extend into powerful automatic learning systems, examples of which are found in [36] and [38].     

Madura: A Language for Learning Vision Programs from Examples

Recently the idea of designing a computer system which automatically connects a number of independent vision modules together to solve a given computer vision problem has attracted significant interest. However the main assumption of this endeavour, namely that the modules used as the building blocks of the vision system are essentially fixed, is questionable in the light of previous experience. Therefore it is important to be able to modify even the detailed operation of the basic modules used, something which is not practical using conventional techniques.This paper constructs a general method by which the computer code of a vision module can be altered automatically to make it mimic a desired behaviour. The system which does this, termed L, modifies a basic module template using interaction with an Oracle as a guide. The Oracle is an entity which, when given an input value, produces the corresponding output of the function which is to be mimicked. The system developed is based upon a new model of computation which endows it with the important properties that extracting the template (i.e. structure) of any module's computer code, as well as determining the best questions to pose to the Oracle are both performed automatically. Thus the L described has significant advantages over many other models which might be used (e.g. Neural Networks).Dealing directly with this new model is not always convenient. Therefore a new computer language Madura is defined which provides a high-level interface to it. As Madura is syntactically similar to JAVA, it is simple to express the code of many basic vision modules in its terms and the results of L (the Madura code of a module which mimics the Oracle) are similarly simple to understand and use.This paper shows a number of results which demonstrate how the L developed can learn many state-of-the-art initial vision algorithms in a matter of minutes. The current and future impact of this work is also examined.     

An Order-Based Theory of Updates for Closed Database Views

The fundamental problem in the design of update strategies for views of database schemata is that of selecting how the view update is to be reflected back to the base schema. This work presents a solution to this problem, based upon the dual philosophies of closed update strategies and order-based database mappings. A closed update strategy is one in which the entire set of updates exhibit natural closure properties, including transitivity and reversibility. The order-based paradigm is a natural one; most database formalisms endow the database states with a natural order structure, under which update by insertion is an increasing operation, and update by deletion is decreasing. Upon augmenting the original constant-complement strategy of Bancilhon and Spyratos – which is an early version of a closed update strategy – with compatible order-based notions, the reflection to the base schema of any update to the view schema which is an insertion, a deletion, or a modification which is realizable as a sequence of insertions and deletions is shown to be unique and independent of the choice of complement. In addition to this uniqueness characterization, the paper also develops a theory which identifies conditions under which a natural, maximal, update strategy exists for a view. This theory is then applied to a ubiquitous example – single-relational schemata constrained by equality-generating dependencies. Within this framework it is shown that for a view defined as a projection of the main relation, the only possibility is that the complement defining the update process is also a projection, and that the reconstruction is based upon functional dependencies.     

Optimizing Procedure Calls for Delayed Non-local Execution Protocol

This work originated from the challenge to strengthen a C-like language compiler developed to support the compilation of sleepers, which are tools which allow complete access to the run-time stack in a delayed non-local execution protocol. Sleepers use a specialized form of procedure call, for which the gain in time execution and space memory allocation becomes a crucial need. These two objectives have been attained thanks to a methodology which generalizes the traditional distinction between tail-calls and normal-calls, introducing the orthogonal distinction between calls in which the calling environment is needed after the call site and calls in which it is not. These two dichotomies divide the space of calls into four classes. The strategy described in this paper is a simple and general framework which can be used to optimize the call-procedure statement in C compilers. The paper discusses optimization techniques appropriate to each class in turn, providing code details for SPARC and ALPHA processors.     

ROBOT_S: An interactive robot simulation language

While it may not be practical to realize a tentative robot design as an actual robot, there is no question of the practicality of a simulation, ROBOT_S is a program in which the foundation for a comprehensive simulation environment is laid. A graphical robot is created to which physical attributes may be assigned, and whose movement may be dictated by a user-installed dynamic model and control law. A simple robot command language has been developed, by which the manipulator may be commanded to move, during which simulation data of state variables is collected and graphed.     

An Adaptive Method for Area Light Sources and Daylight in Ray Tracing

This paper proposes an adaptive method for taking both (diffuse or not) planar area light sources and daylight into account in a ray tracing environment which separates the calculation of direct and indirect illumination. In a given point, direct illumination due to a light source or to natural light is represented by a vector, the direction and magnitude of which being computed through an adaptive area approach, which is driven by the solid angle according to which a part of the source is seen from the current point. In the case of unoccluded diffuse polygonal sources, an analytical formula is used which gives an exact value for this vector.     

The complexity of embedded axiomatization for a class of closed database views

It is well known that the complexity of testing the correctness of an arbitrary update to a database view can be far greater than the complexity of testing a corresponding update to the main schema. However, views are generally managed according to some protocol which limits the admissible updates to a subset of all possible changes. The question thus arises as to whether there is a more tractable relationship between these two complexities in the presence of such a protocol. In this paper, this question is addressed for closed update strategies, which are based upon the constant-complement approach of Bancilhon and Spyratos. The approach is to address a more general question – that of characterizing the complexity of axiomatization of views, relative to the complexity of axiomatization of the main schema. For schemata constrained by denial or consistency constraints, that is, statements which rule out certain situations, such as the equality-generating dependencies (EGDs) or, more specifically, the functional dependencies (FDs) of the relational model, a broad and comprehensive result is obtained in a very general framework which is not tied to the relational model in any way. It states that every such schema is governed by an equivalent set of constraints which embed into the component views, and which are no more complex than the original set. For schemata constrained by generating dependencies, of which tuple-generating dependencies (TGDs) in general and, more specifically, both join dependencies (JDs) and inclusion dependencies (INDs) are examples within the relational model, a similar result is obtained, but only within a context known as meet-uniform decompositions, which fails to recapture some important situations. To address the all-important case of relational schemata constrained by both FDs and INDs, a hybrid approach is also developed, in which the general theory regarding denial constraints is blended with a focused analysis of a special but very practical subset of the INDs known as fanout-free unary inclusion dependencies (fanout-free UINDs), to obtain results parallel to the above-mentioned cases: every such schema is governed by an equivalent set of constraints which embed into the component views, and which are no more complex than the original set. In all cases, the question of view update complexity is then answered via a corollary to this main result. Parts of this paper are based upon work reported in [21].     

基于B/S模式的网页防火墙的构建

针对当前防火墙技术中一套访问控制规则适用于局域网所有用户的设计理念的局限性,提出了一种基于Linux平台的、利用PHPl技术、融合包过滤与代理技术的防火墙设计方案,并开发出基于B/S模式的多用户并发防火墙实验系统,使每个用户能够通过WEB网页制定只针对自己的防火墙访问控制规则。     

An anti-windup scheme for multivariable nonlinear systems

In this paper, an approach to control synthesis for constrained multivariable nonlinear systems using feedback linearization is described. The synthesis of a multivariable saturation element which preserves the directionality of the input vector and produces control action which upholds constraints within the original coordinate system is discussed. Nominal stability analysis is performed using nonlinear μ-analysis for a restricted region of the state-space. A set of conditions is obtained which defines the region of the state space over which the stability analysis is applicable. The results are applied to both a numerical example and to a multivariable polymerization reactor model.     

一种基于市场机制的计算网格资源分配方法

针对计算网格提出了一种基于市场机制的资源分配方法，以一般均衡理论为基础，依靠市场机制，实现计算网格资源的优化分配，首先，描述了基于代理的资源分配框架，它包括3个 层次：资源层、代理层和用户层；接着，给出了计算网络资源分配的市场模型，其中效用函数用于刻画用户对给定资源的满意程度；然后定义了市场模型的均衡状态并证明了均衡状态撮优性，这意味着在均衡状态下资源分配不仅有效而且公平，最后引入了资源代理的迭代算法。