Speaker: Amir Burin

M.Sc. student under the supervision of Dr. Ofer Shayevitz

Sunday, June 18^th, 2017 at 15:00

Room 011, Kitot Bldg., Faculty of Engineering

Reducing Guesswork via an Unreliable Oracle

The problem of guessing random variables has many different implications in coding theory, information theory, cryptography and discrete searching and sorting algorithms. Usually, one is interested in the minimal expected number of guesses required to correctly guess a realization of a random variable. In this work, we consider the case where prior to guessing, the guesser has access to an all-knowing but possibly malicious oracle that allows him to ask a binary question of his choosing. We are interested in the most useful question the guesser can ask in terms of reducing his expected number of guesses, as well as in the associated reduction in guesswork.

Specifically, we consider the following setup. Alice holds an r.v. X, and Bob is trying to guess its value by asking questions of the form ``is X=x?''. Alice answers truthfully and the game terminates once Bob guesses correctly. Before the game begins, Bob is allowed to reach out to an oracle, Carole, and ask her any yes/no question, i.e., a question of the form ``is X in A?''. Carole is known to lie with a given probability 0≤p≤1/2. What should Bob ask Carole if he would like to minimize his expected guessing time?

When Carole is truthful (p=0), it is easy to show that Bob should order the symbol probabilities in descending order, and ask Carole whether the index of X w.r.t. this order is even or odd. We show that this strategy is almost optimal for any lying probability p, up to a small additive constant upper bounded by a 1/4. 

School of Mechanical Engineering Seminar
Wednesday, June 14, 2017 at 14:00
Tokhna Building, Room 101

Macro algae yield enhancement by flashing light

Oz Habiby

MSc Student of Prof. Alex Liberzon Alex and Dr. Alex Golberg

The growing population of the world demands more sources of food, energy and chemicals. As the arable area of the planet is being used widely the marine hold an unfulfilled potential. Marine biomass does not require potable water and does not compete the traditional agriculture on and land use and resources. One of the major bottle necks for this vision to fulfill is the biomass productivity per installed unit area. To create a cost effective industry, the product yield must be enhanced. One of many approaches to address the problem is to increase biomass production efficiency. However, to date there has been a lack of controlled laboratory studies of macro algae growth in physiological conditions relevant to the offshore cultivation.

To fill this gap, a laboratory scale macro algae photo bioreactor (M-PBR) was designed, assembled and operated in order to examine physiological parameters such as illumination influence. The illumination is being controlled separately to each reactor and enables to test different light related parameters, such as intensity or flashing light effect.

The algae growing in the M-PBR has performed 30% daily growth rate with efficiency of 1.11% (PAR spectrum|) in transformation of photons to biomass. Using the flashing light effect enables us to grow the algae with efficiency 5.68%.

 The effect of growth under flashing light can be used for sharing sunlight energy between several depth layers of algae by periodic exposure. This concept could in principle enhance the yield per installed area up to 5 times in a future offshore cultivation.

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על הקשר בין הנדסת מזון לתרבות האכילה הישראלית

מדוע ילדים אוהבים כל-כך לאכול במבה? מה סוד קסמו של השניצל הביתי? 

איזה אלגוריתם יעיל להכנת שיפודי פרגית? מה הקשר בין גודל הצלחת למחיר המנה במסעדה?

 הרצאתו של ד"ר יחיל צבן

 יום רביעי 28.06.17

18:30-20:30

 יש להרשם מראש על מנת להבטיח מקומך