Multi-domain collaborative exploration mechanisms for query expansion in an agent-based filtering framework

Novice users often do not have enough domain knowledge to create good queries for searching information on-line. To help alleviate the situation, exploration techniques have been used to increase the diversity of the search results so that not only those explicitly asked will be returned, but also those potentially relevant ones will be returned too. Most existing approaches, such as collaborative filtering, do not allow the level of exploration to be controlled. Consequently, the search results can be very different from what is expected. We propose an exploration strategy that performs intelligent query processing by first searching usable old queries, and then utilising them to adapt the current query, with the hope that the adapted query will be more relevant to the user’s areas of interest. We applied the proposed strategy to the implementation of a personal information assistant (PIA) set up for user evaluation for 3 months. The experimental results showed that the proposed exploration method outperformed collaborative filtering, and mutation and crossover methods by around 25% in terms of the elimination of off-topic results.     

Evolution strategies with cumulative step length adaptation on the noisy parabolic ridge

This paper presents an analysis of the performance of the (μ/μ,λ)-ES with isotropically distributed mutations and cumulative step length adaptation on the noisy parabolic ridge. Several forms of dependency of the noise strength on the distance from the ridge axis are considered. Closed form expressions are derived that describe the mutation strength and the progress rate of the strategy in high-dimensional search spaces. It is seen that as for the sphere model, larger levels of noise present lead to cumulative step length adaptation generating increasingly inadequate mutation strengths, and that the problem can be ameliorated to some degree by working with larger populations.     

Adaptive Hypermedia

Adaptive hypermedia is a relatively new direction of research on the crossroads of hypermedia and user modeling. Adaptive hypermedia systems build a model of the goals, preferences and knowledge of each individual user, and use this model throughout the interaction with the user, in order to adapt to the needs of that user. The goal of this paper is to present the state of the art in adaptive hypermedia at the eve of the year 2000, and to highlight some prospects for the future. This paper attempts to serve both the newcomers and the experts in the area of adaptive hypermedia by building on an earlier comprehensive review (Brusilovsky, 1996; Brusilovsky, 1998).     

Dynamic Control of Walking Cycle with Initiation Process for Humanoid Robot

This paper focuses on numerical method to solve the dynamic equilibrium of a humanoid robot during the walking cycle with the gait initiation process. It is based on a multi-chain strategy and a dynamic control/command architecture previously developed by Gorce. The strategy is based on correction of the trunk center of mass acceleration and force distribution of the forces exerced by the limbs on the trunk. This latter is performed by mean of a Linear Programming (LP) method. We study the gait initiation process when a subject, initially in quiet erect stance posture, performs a walking cycle. In this paper, we propose to adjust the method for the multiphases (from double support to single support) and multicriteria features of the studied movement. This is done by adapting some specific constraints and criteria in order to ensure the global stability of the humanoid robot along the task execution. For that, we use a Real-Time Criteria and Constraints Adaptation method. Simulation results are presented to demonstrate criteria and constraints influences on the dynamic stability.     

ATM信令适配的差错控制

文章讨论了ＡＴＭ信令适配的差错控制问题,分析了ＡＴＭ信令适配层ＣＲＣ校验的可靠性以及信令协议所采用的选择重传ＡＲＱ的特点。     

三峡-葛洲坝两坝间现行船队通航流量适应能力研究

三峡—葛洲坝两坝间河道通航难点段诸多,河道蜿蜒曲折,沟壑浅滩水流紊乱,并存在泡漩等不利的险恶流态,给船舶(队)的航行安全带来隐患。介绍了5套运行较多、具有代表性的船舶(队),在两坝间来流量45 000～35 000 m3/s时进行的通航船模试验成果。在来流量40 000 m3/s以下,各船队可通过两坝间各困难航段,其航行指标基本满足船队安全航行的要求,500 t以下的各小型船队应限定在来流量35 000 m3/s以下航行,较为安全;两坝间河道的6个困难航段中,上行较难的为喜滩和狮子垴段,居中为莲沱段、其次为石牌、偏垴和南津关段。该研究成果对今后两坝间行船有一定的实用价值和指导意义。     

军校新生学员的转型问题探析

为使军校新生学员尽快融入军校的知识学习和军事训练之中,归纳了军校新生学员因环境变化而带来的思想、生活、自主学习、心理和人际交流等5个方面＂不适应＂的主要表现,分析了产生这些＂不适应＂表现的家庭、社会教育和新生自身3种主要原因,提出了加强思想教育和心理适应教育、确立学习奋斗目标、改进学习方法、教员注意教法上的衔接、营造和谐的学习生活环境、发挥队干部和新生干部作用等主要措施.     

Iterative learning of grasp adaptation through human corrections

In the context of object interaction and manipulation, one characteristic of a robust grasp is its ability to comply with external perturbations applied to the grasped object while still maintaining the grasp. In this work, we introduce an approach for grasp adaptation which learns a statistical model to adapt hand posture solely based on the perceived contact between the object and fingers. Using a multi-step learning procedure, the model dataset is built by first demonstrating an initial hand posture, which is then physically corrected by a human teacher pressing on the fingertips, exploiting compliance in the robot hand. The learner then replays the resulting sequence of hand postures, to generate a dataset of posture-contact pairs that are not influenced by the touch of the teacher. A key feature of this work is that the learned model may be further refined by repeating the correction-replay steps. Alternatively, the model may be reused in the development of new models, characterized by the contact signatures of a different object. Our approach is empirically validated on the iCub robot. We demonstrate grasp adaptation in response to changes in contact, and show successful model reuse and improved adaptation with additional rounds of model refinement.     

Downlink call admission control with power allocation and rate scheduling for IDMAbased multibeam satellite systems

Considering the advantage of interleave-division multiple-access (IDMA) technique and the technical bottlenecks in the existing satellite systems,IDMA is introduced into satellite communication network...     

高等教育人才培养结构与经济结构调整相适应的因素分析

随着我国经济结构调整步伐加快,高等教育的结构性矛盾日益凸显,人才市场呈现人才过剩和结构性短缺并存。阐述了人才培养结构与经济结构调整相适应的现实意义,分析了二者的相互关系,并从人才培养的层级结构、类型结构、学科专业结构、能力素质结构等因素进行了剖析。