From academic writing to job-related writing: achieving a smoothtransition

Do university writing experiences prepare students for future job-related writing tasks? If not, how can we create a smoother transition from the academy to the workplace? The author analyzes the differing discourse communities of academic writing and technical communication which may limit the transfer of skills from one arena to the next. The discussion considers the ways process, collaborative learning, writing across the curriculum, and language theories can form the foundation for constructive communication among disciplines. As the focus of academic writing moves from an emphasis on the individual to social context and wider audiences, it bridges the gap between disciplines and can ease the movement from the classroom to real-world settings     

光电子显微术的原理和应用

近十年来,光电子显微技术取得了长足进步并已商业化。光电子显微是一种高衬度的成像技术,对材料表面电子结构高度敏感。本文介绍光电子显微镜的成像原理,并着重分析其衬度机制。简要总结光电子显微术在表面结构分析,表面化学,磁学,以及半导体器件表征等方面的应用。目前光电子显微术的两个重要发展方向是利用同步辐射光源和脉冲激光光源做激发源;利用脉冲激光的多光子激发光电子显微术可以对较高功函数（大于光子能量）的材料成像;而脉冲时间分辨光电子显微术可用来研究表面瞬态电子的弛豫动力学机制。文章介绍了在实现飞秒时间分辨以及多光子激发的光电子显微方面的进展。我们利用多光子光电显微术对溅射制备的纳米结构银薄膜表面进行成像,结果表明多光子成像照片上存在一些高强度的亮点,而在单光子成像照片未观察到类似现象。推测这些亮点源于纳米结构银表面的等离子激元的高局域选择性激发。文章还介绍了利用光电子显微术原位观察CuZnAl形状记忆合金的热诱导相变。     

Coherent optical frequency combs: From principles to applications

A coherent optical frequency comb is a kind of broad-spectrum light sources delivering equidistant frequencies, and correspondingly its temporal waveform appears as a sequence of ultrashort pulses. Being the cornerstone technology of today's laser and time-frequency disciplines, it effectively links the optical frequency and the microwave frequency, and has promoted the development of diverse applications, such as precision spectroscopy, optical measurement, coherent optical communications, and optical clocks in the past two decades. In this review, we comprehensively introduce the development path, physical principle, generation/tuning methods, and advanced applications of optical frequency combs.     

Turbo estimation algorithms: general principles, and applications to modal analysis

In this paper, a new class of parameter estimation algorithms, called turbo estimation algorithms (TEA), is introduced. The basic idea is that each estimation algorithm (EA) must perform a sort of intrinsic denoising of the input data in order to achieve reliable estimates. Optimum algorithms implement the best possible noise reduction, compatible with the problem definition and the related lower bounds to the estimation error variance; however, their computational complexity is often overwhelming, so that in real life one must often resort to suboptimal algorithms; in this case, some amount of noise could be still eliminated. The TEA methods reduce the residual noise by means of a closed loop configuration, in which an external denoising system, fed by the master estimator output, generates an enhanced signal to be input to the estimator for next iteration. The working principle of such schemes can be described in terms of a more general turbo principle, well known in an information theory context. In this paper, an example of turbo algorithm for modal analysis is described, which employs the Tufts and Kumaresan (TK) method as a master EA.     

Turbo equalization: principles and new results

We study the turbo equalization approach to coded data transmission over channels with intersymbol interference. In the original system invented by Douillard et al. (1995), the data are protected by a convolutional code and the receiver consists of two trellis-based detectors, one for the channel (the equalizer) and one for the code (the decoder). It has been shown that iterating equalization and decoding tasks can yield tremendous improvements in bit error rate. We introduce new approaches to combining equalization based on linear filtering, with decoding.. Through simulation and analytical results, we show that the performance of the new approaches is similar to the trellis-based receiver, while providing large savings in computational complexity. Moreover, this paper provides an overview of the design alternatives for turbo equalization with given system parameters, such as the channel response or the signal-to-noise ratio     

Further comments on `Modes of elliptical waveguides: a correction'[and reply]

For the original article see ibid., vol.38, no.11, p.1603-8 (1990). The commenters dispute the assertion by D.A. Goldberg et al. in the above named work that an error in the field configurations plotted by L.J. Chu (1938) had gone undetected for five decades. The authors' reply is included     

Methodological principles of T wave alternans analysis: a unified framework

Visible T wave alternans (TWA) in the electrocardiogram (ECG) had been regarded as an infrequent phenomenon during the first 80 years of electrocardiography. Nevertheless, computerized analysis changed this perception. In the last two decades, a variety of techniques for automatic TWA analysis have been proposed. These techniques have allowed researchers to detect nonvisible TWA in a wide variety of clinical and experimental conditions. Such studies have recently shown that TWA is related to cardiac instability and increased arrhythmogenicity. Comparison of TWA analysis methods is a difficult task due to the diversity of approaches. In this paper, we propose a unified framework which holds the existing methods. In the light of this framework, the methodological principles of the published TWA analysis schemes are compared and discussed. This framework may have an important role to develop new approaches to this problem.     

Tackling the needs of foreign academic writers: a case study

Foreign engineers and scientists must publish their research in professional journals in English, but they often lack the proficiency and skills to do so successfully. The commentary describes a course that teaches these skills to Ph.D. students before they enter the job market. The techniques described are also effective tools for teaching professionals in the workplace     

Sliding mode control design principles and applications to electricdrives

The basic concepts, mathematics, and design aspects of variable-structure systems as well as those with sliding modes as a principle operation mode are treated. The main arguments in favor of sliding-mode control are order reduction, decoupling design procedure, disturbance rejection, insensitivity to parameter variations, and simple implementation by means of power converters. The control algorithms and data processing used in variable structure systems are analyzed. The potential of sliding mode control methodology is demonstrated for versatility of electric drives and functional goals of control     

An introduction to the principles and applications of holography

Holography has strong historical ties with electrical engineering and potential application to many electrical engineering problems. The basic problem addressed by holography is introduced in both physical and mathematical terms. The analogy between the hologram of a point-source object and the linear FM signals of chirp radar is stressed, and the first-order imaging properties of holograms recorded in arbitrary geometries are derived. Various types of holograms are described, including thin, thick, transmission, reflection, amplitude, and phase holograms. The important properties of each type of hologram are introduced. A survey of various applications of holography is presented, with introductions to the use of holography in interferometry, microscopy, imaging through distorting media, optical data processing, and optical data storage. The use of simple holograms as optical elements is also described.     

Improvements in W-CDMA: principles and experimental results

This article first reviews the channel structure and spreading code assignment for the physical layer and transport channel multiplexing along with a sophisticated rate-matching scheme that accommodates composite transport channels with various levels of quality of service (QoS) on one physical channel. Then, the key technologies of wideband ds-cdma (w-cdma) wireless access are presented and the results of experiments pertaining to these technologies are evaluated. Flexible system deployment is possible by employing inter-cell asynchronous operation with a three-step fast cell search method. The signal-to-interference power ratio (sir) measurement based fast transmit power control (tpc) guarantees the minimum transmit power according to the channel load and the changes in the link conditions due to fading. Furthermore, various diversity technologies are described such as pilot symbol-assisted (psa) coherent Rake combining, antenna diversity, site diversity (soft/softer handover), and transmit diversity in the forward link that are effective in decreasing the required transmit power, which results in increases system capacity. This article also presents link-capacity enhancing techniques such as using an interference canceller (IC) and adaptive antenna array diversity (AMD) receiver/transmitter. Experimental results are presented for an actual multipath fading channel that indicate the potential of the IC and aaad transceiver to decrease the mobile transmit power in the reverse link and interference from high rate users with high transmit power in the forward link.     

Telepresence technology in medicine: principles and applications

Telepresence systems can improve surgeons' performance in minimally invasive surgery (MIS) and microsurgery and also enable them to operate on patients remotely over great distances. In MIS, telepresence technology allows surgeons to experiment surgery as if their hands and eyes were effectively inside the patient's closed abdomen, enabling them to work with improved skill and dexterity. In microsurgery, the technology can scale down the surgeons' motions, forces, and field of view, allowing them to skillfully operate on microscopic anatomy with relative ease. The systems also enable surgeons to treat patients remotely in inaccessible or hazardous locations with great effectiveness, allowing them to operate as if they were present at the remote site. The means for conveying human presence in such systems is through force-reflecting manipulators with digital servo controllers, stereo viewing systems, and communication links. Depending on the application, the surgeon at the telepresence workstation may be across the room from the patient or across the state, connected by a microwave link or communication network     

Quantifying information transfer through a head-attached vibrotactile display: principles for design and control

Vibrotactile displays can extend the perception capabilities of visually impaired persons. Placing such devices on the head promises easy attachment and detachment without reducing other interaction abilities. However, the effectiveness of head-attached vibrotactile displays has never been thoroughly tested. This paper presents the results obtained from experiments with 22?subjects equipped with a display containing 12 coin-type motors equally spaced in a horizontal plane around the upper head region. Our display allowed single- as well as multimotor activation with up to six simultaneously active motors. We identified the minimum and comfort strength of vibrotactile stimulation, and measured the precision in perceiving the accurate number of active motors as well as the precision in localizing the stimuli on the head. While subjects identified the correct number of active motors in 94% of the cases when presented with only one active motor, this precision dropped to 40% for two and down to 5% for five simultaneously active motors. This strongly suggests to avoid multipoint stimulation even though the precision of localizing a position of a stimulus on the head is barely affected by the number of simultaneously active motors. Localization precision, however, varied significantly with the region of the head suggesting that the most front and back regions of the head should be avoided if high precision is required.     

Comments on `Analysis of superconducting microwave structures:application to microstrip lines' [and reply]

For the original article see ibid., vol.40, no.3, p.499-508 (1992). The commenters present experimental and theoretical evidence that purports to show that in the above-titled paper by S.M. El-Ghazaly et al. and an earlier paper by the same authors, the distribution of longitudinal current component J in the transverse plane is related to the surface charge density ρ_S and the distribution of J_z in the transverse plane varies with the dielectric constant of the substrate. El-Ghazaly replies that the commenters failed to understand some salient features of his papers. Also, he argues that they overestimate the application of Wheeler's approximation, namely the inductance per unit length is independent of the dielectric constant in transmission lines, and he provides clarification     

Optical reflectance and transmittance of tissues: principles andapplications

A discussion is presented of diagnostic and dosimetric optical measurements in medicine and biology. Topics covered include: tissue optical properties, tissue boundary conditions, and invasive versus noninvasive measurements. Clinical applications of therapeutic dosimetry and diagnostic spectroscopy are discussed. The principles of diffuse reflectance and transmittance measurements are presented. Experimental studies illustrate reflectance spectroscopy and steady-state versus time-resolved measurements     

Self-organization in communication networks: principles and design paradigms

The trend toward ubiquitous wireless communication demands for a higher level of self-organization in networks. This article gives an introduction and overview on this topic and investigates the fundamental question: What are design paradigms for developing a self-organized network function? We propose four paradigms and show how they are reflected in current protocols: design local interactions that achieve global properties, exploit implicit coordination, minimize the maintained state, and design protocols that adapt to changes. Finally, we suggest a general design process for self-organized network functions.     

Particle detectors for future collider experiments: a description of basic principles and general characteristics

The study of the high-energy frontier of particle physics relies on collider experiments. Colliders are accelerators where two opposite-direction particle beams collide and interact in a small and fixed region to gain from the maximum energy provided by the machine. In fact, the particle relativistic-kinematics ensures that collisions give much larger energy for experimental purposes than beam interaction with fixed targets. In this article, the basic principles for particle detection and the consequent general detector characteristics are described, followed by more details of the most important experimental setups.