Playing Mastermind with Constant-Size Memory

We analyze the classic board game of Mastermind with n holes and a constant number of colors. The classic result of Chvátal (Combinatorica 3:325–329, 1983) states that the codebreaker can find the secret code with Θ(n/logn) questions. We show that this bound remains valid if the codebreaker may only store a constant number of guesses and answers. In addition to an intrinsic interest in this question, our result also disproves a conjecture of Droste, Jansen, and Wegener (Theory Comput. Syst. 39:525–544, 2006) on the memory-restricted black-box complexity of the OneMax function class.     

Tight analysis of the (1+1)-EA for the single source shortest path problem

We conduct a rigorous analysis of the (1+1) evolutionary algorithm for the single source shortest path problem proposed by Scharnow, Tinnefeld, and Wegener (The analyses of evolutionary algorithms on sorting and shortest paths problems, 2004, Journal of Mathematical Modelling and Algorithms, 3(4):349-366). We prove that with high probability, the optimization time is O(n2 max{?, log(n)}), where ? is the smallest integer such that any vertex can be reached from the source via a shortest path having at most ? edges. This bound is tight. For all values of n and ? we provide a graph with edge weights such that, with high probability, the optimization time is of order Ω(n2 max{?, log(n)}). To obtain such sharp bounds, we develop a new technique that overcomes the coupon collector behavior of previously used arguments. Also, we exhibit a simple Chernoff type inequality for sums of independent geometrically distributed random variables, and one for sequences of random variables that are not independent, but show a desired behavior independent of the outcomes of the previous random variables. We are optimistic that these tools find further applications in the analysis of evolutionary algorithms.     

Evaluation of a low-cost 3D sound system for immersive virtual reality training systems

Since head mounted displays (HMD), datagloves, tracking systems, and powerful computer graphics resources are nowadays in an affordable price range, the usage of PC-based "virtual training systems" becomes very attractive. However, due to the limited field of view of HMD devices, additional modalities have to be provided to benefit from 3D environments. A 3D sound simulation can improve the capabilities of VR systems dramatically. Unfortunately, realistic 3D sound simulations are expensive and demand a tremendous amount of computational power to calculate reverberation, occlusion, and obstruction effects. To use 3D sound in a PC-based training system as a way to direct and guide trainees to observe specific events in 3D space, a cheaper alternative has to be provided, so that a broader range of applications can take advantage of this modality. To address this issue, we focus in this paper on the evaluation of a low-cost 3D sound simulation that is capable of providing traceable 3D sound events. We describe our experimental system setup using conventional stereo headsets in combination with a tracked HMD device and present our results with regard to precision, speed, and used signal types for localizing simulated sound events in a virtual training environment     

Optimal hardware and software design of an image-based system for capturing dynamic movements

In contrast to conventional image-capture systems, which attempt to minimize the amount of data collected during capture, typically by using hardware filters, the more general condition of using all information captured on a camera sensor is much more challenging and requires rigorous consideration of the hardware and software pipelines to obtain accurate tracking results. In this paper, this issue is specifically addressed by describing a unique hardware and software design implemented for use as a fully image-based capture system. An attempt is made to minimize the cost of this system by maximizing hardware control through software implementation. The hardware and software requirements are described in the context of the desired high-speed capture suitable for earthquake motions or other dynamic movements in a scene. Experiments are conducted and presented illustrating the good performance and stability of the system. This system is deemed suitable for the general condition of a building interior.     

107-gb/s optical signal generation using electronic time-division multiplexing

This paper reports the first optical transmitter implementations operating at a serial bit rate of 107 Gb/s using solely electronic time-division multiplexing. Two methods to overcome modulator bandwidth limitations are proposed and demonstrated: low-bandwidth optical duobinary modulation and integrated optical equalization. Both transmitters are characterized in terms of bit error ratio and chromatic dispersion tolerance.     

Simple method for mitigation of polarization crosstalk in silica planar lightwave circuit directional couplers

Polarization crosstalk in planar lightwave circuit directional couplers can cause significant polarization-dependence in interferometers that use them. We show a simple way to mitigate the polarization crosstalk without incurring a performance penalty or requiring extra fabrication steps. We demonstrate it on a 23-ps Mach-Zehnder delay interferometer.     

Serum hepatitis G virus (HGV) RNA in multitransfused thalassemics from eastern Sicily

To evaluate the efficacy of continuous administration of 50% nitrous oxide in oxygen for reducing pain during flexible fiberoptic bronchoscopy 32 children aged 3-60 months were randomly assigned to an experimental or a control group. Indications for endoscopy included persistent atelectasis (6), wheezing (10) cystic fibrosis (2) pneumonia (11) persistent cough (3). All patients received Midazolam (0.3 mg/kg) atropine (20 mcg/kg) intra rectaly 20 minutes before the procedure. The flexible fiberoptic bronchoscope (Olympus BF3C4) was inserted transnasally through a face mask. Topical anesthesia with 1% lidocaine hydrochloride (3 mg/kg) was applied to the nose, larynx, trachea and bronchial tree over 15 minutes through the suction chanel of the bronchoscope. All patients were monitored with a pulse oximeter and a cardiac monitor. The experimental group (n = 16) received 50% nitrous oxide in oxygen prior (3 minutes) and during flexible fiberoptic bronchoscopy, the control group (n = 16) received only oxygen. We measured pain of the children by a behavioral observation scale (Children's Hospital of Eastern Ontario Pain Scale: CHEOPS) at each phase of topical anesthesia during bronchoscopy in the two groups. At the end of bronchoscopy physician's satisfaction was scored by a visual analogue scale (VAS 0-100) in which 0 corresponded to absence of satisfaction. Nitrous oxide was associated with lesser pain scores than those with oxygen. Physician significantly preferred these procedure compared with oxygen. No complication occurred during procedure. Combined with local anesthesia midazolam and atropin the administration of 50% nitrous oxide in oxygen seems a better choice for flexible fiberoptic bronchoscopy in children and should be used routinely.