Effects of three‐dimensional virtual reality and traditional training methods on mental workload and training performance

Industries will implement effective training programs to improve training performance, and an ideal training performance occurs under proper mental workload (MWL). Virtual reality (VR) has recently been widely utilized in training; however, only a few studies have investigated its effects on MWL and training performance simultaneously. The purpose of this study is to investigate the effects of VR training and traditional training methods, such as technical manuals (TM) and multimedia films (MF), on training performance and MWL. The results of the performance measurement show that VR training is considered the best training method compared to TM and MF, particularly in the case of complex tasks. The results of physiological measurements (GSR [galvanic skin response], LF% [low frequency], and LF/HF [high frequency] ratio) show a significant difference between reading TM and using computer (MF and VR), wherein the latter has a lower MWL. However, no significant difference in subjective MWL assessment (NASA‐TLX [task load index]) and HF% measurement is found.     

Planning Intelligent Responses in a Natural Language System

Intelligent help systems cannot merely respond passively to the user'scommands and queries. They need to be able to volunteer information,correct user misconceptions, and reject unethical requests when appropriate.In order to do these things, a system must be designed as an intelligentagent. That is, a system needs to have its own goals and then plan forthese goals. A system which did not have its own goals would never refuseto help users perform unethical actions.Such an intelligent agent has been implemented in the UCEgo component of UC(Wilensky et al. 1984; Wilensky et al. 1988) (UNIX Consultant), a natural languagesystem that helps the user solve problems in using the UNIX operatingsystem. UCEgo provides UC with its own goals and plans. By adoptingdifferent goals in different situations, UCEgo creates and executesdifferent plans, enabling it to interact appropriately with the user.UCEgo adopts goals when it notices that the user either lacks necessaryknowledge, or has incorrect beliefs. In these cases, UCEgo plans tovolunteer information or correct the user's misconception as appropriate.These plans are pre-stored skeletal plans that are indexed under the types ofsituations in which they are typically useful. Plan suggestion situationsinclude the goal which the plan is used to achieve, the preconditions of theplan, and appropriateness conditions for the plan. Indexing plans bysituations improves efficiency and allows UC to respond appropriately to theuser in real time.Detecting situations in which a plan should be suggested or a goal adoptedis implemented using if-detected daemons. These daemons provide asingle mechanism which can be used both for detecting goals and suggestingplans. Different methodologies for the efficient implementation ofif-detected daemons are discussed.     

Answering similarity queries in peer-to-peer networks

A variety of peer-to-peer (P2P) systems for sharing digital information are currently available and most of them perform searching by exact key matching. In this paper we focus on similarity searching and describe FuzzyPeer, a generic broadcast-based P2P system which supports a wide range of fuzzy queries. As a case study we present an image retrieval application implemented on top of FuzzyPeer. Users provide sample images whose sets of features are propagated through the peers. The answer consists of the top-k most similar images within the query horizon. In our system the participation of peers is ad hoc and dynamic, their functionality is symmetric and there is no centralized index.     

Analysis of thinning algorithms using mathematical morphology

A precise definition of digital skeletons and a mathematical framework for the analysis of a class of thinning algorithms, based on morphological set transformation, are presented. A particular thinning algorithm (algorithm A) is used as an example in the analysis. Precise definitions and analyses associated with the thinning process are presented, including the proof of convergence, the condition for one-pixel-thick skeletons, and the connectedness of skeletons. In addition, a necessary and sufficient condition for the thinning process in general is derived, and an algorithm (algorithm B) based on this condition is developed. Experimental results are used to compare the two thinning algorithms, and issues involving noise immunity and skeletal bias are addressed     

基于NB的双级分类模型在邮件过滤中的研究

使用朴素的贝叶斯（NB）分类模型对邮件进行分类，是目前基于内容的垃圾邮件过滤方法的研究热点。朴素的贝叶斯在参数之间联系不强的时候分类效果简单而有效。但是朴素的贝叶斯分类模型中对特征参数的条件独立假设无法表达参数之间在语义上的关系，影响分类性能。在朴素的贝叶斯分类模型的基础上，我们提出了一种双级贝叶斯分类模型（DLB，Double Level Bayes），既考虑到了参数之间的影响又保留了朴素的贝叶斯分类模型的优点。同时时DLB模型与朴素的贝叶斯分类模型的性能进行比较。仿真实验表明，DLB分类模型在垃圾邮件过滤应用中的效果在大部分条件下优于朴素的贝叶斯分类模型。     

基于引力场的基坑悬臂式支挡结构设计与实践

基坑工程的质量依赖于科学合理的基坑设计、详细周密的地质勘察、精心细致的施工作业、可靠有效的实时监测。基坑工程的支护形式多种多样,悬臂式支挡结构就是其中之一,目前尚没有人能对悬臂式支挡结构确切的工作机理给出一个令人满意的解释,悬臂式支挡结构在坑底以下的嵌固深度计算也缺少可靠的理论公式,因此导致悬臂式支挡结构出现事故的现象时有发生,因此悬臂式支挡结构嵌固深度的合理确定就成了悬臂式支挡结构成功与否的关键。以长年的基坑工程实践与理论研究为基础,结合地球引力场理论,对悬臂式支挡结构确切的工作机理作出一个比较切合实际的解释,指出了支挡结构底部与接触岩土体间的摩擦力对悬臂式支挡结构稳定的关键作用,给出了悬臂式支挡结构嵌固深度计算的理论公式和工程实例。     

Superalloy Melting in an ac Electroslag Remelt Furnace with Automatic Melt Control and rms Current Regulation

A stationary mold-ingot bottom withdrawal ac consumable electrode electroslag furnace with electrode change capability has been installed for melting superalloys at Teledyne-Allvac. The furnace, which utilizes melt voltage and rms current regulation for automatic melt control and its operation are described. The stationary mold-ingot bottom withdrawal and auto-melt control concepts have proven successful and solution hardening superalloys are in routine production with high quality and good yield. Additionally, experimental melting of the nickel base and iron base precipitation hardening superalloys (containing titanium and aluminum) is in process, and initial results look encouraging with respect to quality and chemistry control.     

Design,Synthesis and Evaluation of AdSS Bisubstrate Inhibitors

Many cancers lack the expression of methylthioadenosine phosphorylase (MTAP). These cancers require adenylosuccinate synthetase (AdSS) for nucleic acid synthesis. By inhibiting adenylosuccinate synthetase, we potentially have a new therapeutic agent. Bisubstrate inhibitors were synthesized and evaluated against purified AdSS. The best activity was obtained with adenosine bearing a four-carbon linker that connects the N-formyl-N-hydroxy moiety to the 6-position of the purine nucleoside.     

Bioresorbable and degradable behaviors of PGA: Current state and future prospects

Polyglycolic acid (PGA) is a class of semicrystalline, bioresorbable polymers that have been widely used in a number of applications. No other bioresorbable materials can fully replace PGA in tissue engineering. Understanding degradation mechanisms in PGA is important for improving the efficiency and effectiveness in various fields including implantation. This review begins with a discussion on terminology of polymer degradation and hydrolytic degradation mechanism with a delineative model. This review also focus on previous degradation studies taking advantage of its fast-degrading behavior and the mechanism behind hexafluoroisopropanol (HFIP) being the sole solvent for PGA. Finally, the merits of PGA are discussed with many potential future applications along with their associated challenges.     

Study on bioaccessibility of betacyanins from red dragon fruit (Hylocereus polyrhizus)

Food Science and Biotechnology - Betacyanins are bioactive dietary phytochemicals which can be found in red dragon fruit (RDF). Therefore, the bioaccessibility of betacyanins that present in...