A numerical study of ice piece removal from a rectangular tank using a floodgate.

WINICE is a project carried out by researchers at Aalto University and Lappeenranta University. The project aims at investigating wasterwater purification through formation of thin ice layers by natural freezing in regions with cold climate, such that the process is more energy efficient than existing common purification methods. The scope of the project includes purification of wasterwater through formation of thin pure ice sheet in a tank, cutting of the ice sheet into ice pieces, removal of the ice pieces and their transport for further processing. This thesis focuses on a method for collection of the ice pieces after they are cut into pieces. For the collection process, a floodgate located centrally along the width of the tank is opened to generate an outward flow of water, which causes the ice piece to move along with the water. The ice piece is separated and the water is then is pumped back into the tank for refreezing. The scope of this thesis is studying the feasibility of the removal process, effects of reducing ice sheet length on the time taken to extract the ice piece (reach time) and analysis of reach time as a function of ice piece’s initial from the floodgate. The simulation of the ice piece motion is divided in two parts: simulation of water flow under the influence of ice sheet of fixed length, and simulation of a rectangular ice piece motion using the imported water flow field. The ice piece motion simulation is done for several initial positions using flow fields corresponding to different ice sheet lengths. However, the final simulation flow field from an interpolated case of several cases is needed to account for several distortions in the reach time contours. It is found that the floodgate is capable of extracting ice pieces from even farthest positions in the tank and that most of the time to completely empty the tank, would be spent on removing the ice pieces at the farthest positions from the floodgate. This time can be further reduced by using a wider floodgate. There are oscillations observed in the reach time vs. distance plots. Regardless, an average trend is noticed for the majority of the domain. The nature of the trendline is a power function of the form t = Ar^B where t is the reach time, r is the distance of the initial position from the floodgate and A,B are constants. Further exploration of the relationship of A and B with different ice piece and flow parameters along with the experimental validation of this simulation is part of the future work

MOVING TARGET INDICATION RADAR

MTI (Moving Target Indication) radar systems have been built for many years, based on system concepts evolved in the early 1950's. Digital techniques now permit easier implementation, but do not change the basic concepts; staggered repetition periods to eliminate blind speeds; and MTI cancellers with the velocity response shaped by feed forward and feedback techniques. Radar MTI may be specialized in terms of the type of clutter and environment: airborne MTI (AMTI), ground MTI (GMTI), etc., or may be combined mode: stationary and moving target indication (SMTI).The most common approach takes advantage of the Doppler Effect.  Many of the existing systems are very successful considering their performance, measured in terms of MTI improvement factor or sub clutter visibility. In this paper the basic MTI concepts and definitions are presented, and the real problems of modern surface-based MTI radar systems are discussed

Evolution of law on anticipatory bail in India

Sushila Aggarwal v State (NCT of Delhi) forms an important part of the law on anticipatory Bail in India. Prior to Sushila Aggarwal judgment, the law on anticipatory bail in India was ambiguous due to the varying interpretations of section 438 of the Criminal Procedure Code 1973 (anticipatory bail) by the Supreme Court. It was only in the year 2020 that the law on the matter was settled by the Supreme Court in its Sushila Aggarwal judgment. With this paper, the authors aim to trace the evolution of the law on anticipatory bail in India. It focusses on the landmark judgments of the Supreme Court and meanders its way through conflicting opinions of the Court. The paper concludes by welcoming the Sushila Aggarwal judgment for settling the long ambiguous law on anticipatory bail in India. However, it also highlights the concerns that Constitution Bench failed to appreciate, which if addressed would have made the law free of the loopholes presently plaguing the law on anticipatory bail

Survey on Computer Worms

Cyber Security is an important aspect in the field of information technology. Either it is often neglected or given a lesser priority .One of the biggest challenges that we face today is to secure information. The first thing that comes to our mind whenever we think about cyber security is ‘cyber crimes’, which are increasing at a very fast pace. Governments of countries, agencies and companies are taking crucial measures in order to prevent cybercrimes. Despite taking measures cyber security is still a very big concern. This paper mainly lays emphasis on the definition of worms, difference between worms and viruses, behavioural patterns of worms, major categories of worms, aspects of designing of worms, life cycle of worms, history and timeline of worms and a case study of Stuxnet

HIV Nuclear Entry: Clearing the Fog

HIV-1 and other lentiviruses have the unusual capability of infecting nondividing cells, but the mechanism by which they cross an intact nuclear membrane is mysterious. Recent work, including a new study (Lee, K.; Ambrose, Z.; Martin, T.D.; Oztop, I.; Mulky, A.; Julias, J.G.; Vandergraaff, N.; Baumann, J.G.; Wang, R.; Yuen, W. et al. Flexible use of nuclear import pathways by HIV-1. Cell Host Microbe 2010, 7, 221–233) confirms that the viral capsid plays a key role in HIV-1 nuclear entry in both dividing and nondividing cells. The identification of mutations in the viral capsid that alter the virus’s dependence on host cell nucleoporins represents an important advance in this poorly understood stage of the virus life cycle

Challenges in Developing a Collaborative Robotic Assistant for Automotive Assembly Lines

Industrial robots are on the verge of emerging from their cages, and entering the final assembly to work along side humans. Towards this we are developing a collaborative robot capable of assisting humans in the final automotive assembly. Several algorithmic as well as design challenges exist when the robots enter the unpredictable, human-centric and time-critical environment of final assembly. In this work, we briefly discuss a few of these challenges along with developed solutions and proposed methodologies, and their implications for improving human-robot collaboration

ConTaCT: Deciding to Communicate during Time-Critical Collaborative Tasks in Unknown, Deterministic Domains

Communication between agents has the potential to improve team performance of collaborative tasks. However, communication is not free in most domains, requiring agents to reason about the costs and benefits of sharing information. In this work, we develop an online, decentralized communication policy, ConTaCT, that enables agents to decide whether or not to communicate during time-critical collaborative tasks in unknown, deterministic environments. Our approach is motivated by real-world applications, including the coordination of disaster response and search and rescue teams. These settings motivate a model structure that explicitly represents the world model as initially unknown but deterministic in nature, and that de-emphasizes uncertainty about action outcomes. Simulated experiments are conducted in which ConTaCT is compared to other multi-agent communication policies, and results indicate that ConTaCT achieves comparable task performance while substantially reducing communication overhead

Learning Models of Sequential Decision-Making without Complete State Specification using Bayesian Nonparametric Inference and Active Querying

Learning models of decision-making behavior during sequential tasks is useful across a variety of applications, including human-machine interaction. In this paper, we present an approach to learning such models within Markovian domains based on observing and querying a decision-making agent. In contrast to classical approaches to behavior learning, we do not assume complete knowledge of the state features that impact an agent's decisions. Using tools from Bayesian nonparametric inference and time series of agents decisions, we first provide an inference algorithm to identify the presence of any unmodeled state features that impact decision making, as well as likely candidate models. In order to identify the best model among these candidates, we next provide an active querying approach that resolves model ambiguity by querying the decision maker. Results from our evaluations demonstrate that, using the proposed algorithms, an observer can identify the presence of latent state features, recover their dynamics, and estimate their impact on decisions during sequential tasks

Using 3D-printed Patient-optimized Surgical Tools (3D POST) for Complex Hip and Knee Arthroplasty

Planning is a key step in all surgeries. Well-planned cases have better outcomes than the unplanned ones. The conventional planning used to be done on radiographs and other imaging. Three-dimensional (3D) printing using additive manufacturing process has taken this a step further. The process involves converting the radiographic digital formats into machine-printable format. The three-dimensional model is typically made of a plastic material that allows surgical simulation