Generation and evolution of Vortex array with variable-ratio lateral-shearing interferometry

Different from the method by plane-wave interference, here an efficient approach is proposed to generate optical vortex array (VA) based on lateral-shearing interferometer (LSI), in which the evolution from light spot array to VA can be observed by continuously variable shear ratio in a certain range. VAs with topological charge 2 and 1 are simulated by software GLAD and proved to be effectiveness through optical experiment. Theoretical analysis and experimental results show that when the shear ratio approaches to zero, we can stably obtain a vortex array with high density and variable topological charge.

Numerical Simulation of Rod Jet Formed by Shaped Charge under Rigid Constraint

In order to study the forming law of rod jet formed by shaped charge under rigid boundary constraint, ANSYS/LSDYNA finite element software is used to simulate the forming process of rod jet with ALE essential boundary, and the influence of structural parameters of shaped charge on rod jet forming is studied. The results show that compared with the free boundary constraint, the head velocity of rod jet increases by 63.5 % and the tail velocity increases by 59.3 % under the rigid boundary constraint. The head velocity and length-diameter ratio of rod jet decrease with the increase of the outside curvature radius of the liner, the thickness of the liner central position and the variable ratio of wall thickness. Furthermore, the tail velocity increases with the increase of the outside curvature radius of the liner, and decreases with the increase of the thickness of the liner central position and the variable ratio of wall thickness.

Addictive Games: Case Study on Multi-Armed Bandit Game

The attraction of games comes from the player being able to have fun in games. Gambling games that are based on the Variable-Ratio schedule in Skinner’s experiment are the most typical addictive games. It is necessary to clarify the reason why typical gambling games are simple but addictive. Also, the Multiarmed Bandit game is a typical test for Skinner Box design and is most popular in the gambling house, which is a good example to analyze. This article mainly focuses on expanding on the idea of the motion in mind model in the scene of Multiarmed Bandit games, quantifying the player’s psychological inclination by simulation experimental data. By relating with the quantification of player satisfaction and play comfort, the expectation’s feeling is discussed from the energy perspective. Two different energies are proposed: player-side (Er) and game-side energy (Ei). This provides the difference of player-side (Er) and game-side energy (Ei), denoted as Ed to show the player’s psychological gap. Ten settings of mass bandit were simulated. It was found that the setting of the best player confidence (Er) and entry difficulty (Ei) can balance player expectation. The simulation results show that when m=0.3,0.7, the player has the biggest psychological gap, which expresses that player will be motivated by not being reconciled. Moreover, addiction is likely to occur when m∈[0.5,0.7]. Such an approach can also help the developers and educators increase edutainment games’ efficiency and make the game more attractive.

The Effect Of Price Earning Ratio, Current Ratio, Net Profit Margin And Debt To Equity Ratio On Stock Prices Of The Lq-45 Index Of The Indonesia Stock Exchange 2016-2018

This study aims to analyze the joint and partial effect of the price earning ratio, current ratio, net profit margin, and debt to equity ratio variables on the stock prices of companies listed on the LQ-45 Index of the Indonesian Stock Exchange for the 2016-2018 period. The research sample is companies that fall into the LQ-45 stock category, namely 45 companies for the 2016-2018 period using normality, autocorrelation, multicollinearity, and heteroscedasticity tests as classical assumptions using multiple regression analysis methods. The results of the analysis show that the research variable has a significant effect on stock prices in companies in the LQ-45 Index category of the Indonesian stock exchange for the 2016-2018 period and the partial test results show that the price earning ratio variable has no significant effect on stock prices, the current variable ratio and affects stock prices. net profit margin significantly affects stock prices and the debt to equity ratio variable significantly affects stock prices in companies in the LQ-45 Index category of the Indonesian stock exchange for the period 2016 - 2018.

Five-Fingered Passive Force Feedback Glove Using a Variable Ratio Lever Mechanism

Force feedback gloves allow users to touch and manipulate virtual objects intuitively. Compared with gloves providing active feedback force, gloves with passive feedback force are promising in terms of safety and low weight, but simulating the variable stiffness of virtual objects is more challenging. Addressing this difficulty, we propose a five-fingered glove with passive force feedback employing a variable ratio lever mechanism. The stiffness of the proposed glove is tuned by changing the structural stiffness of this mechanism rather than by applying torque control at each joint of the finger. The switch between free and constrained space is realized in real time by locking/unlocking the revolute joints of the glove using a servo motor. Furthermore, a predictive control mode is proposed to reduce the response time of the control system, and the actual response time is less than the limit of the delay (45 ms) that humans can perceive between visual and haptic stimuli. Experimental results show that the linear stiffness at the fingertip ranges from 0.89 to 619.89 N/m, and the maximum backdrive force of the proposed glove is less than 0.147 N.

Ekstraksi Tanin dari Buah Balakka (Phyllanthus emblica L.) dengan Bantuan Microwave: Pengaruh Daya Microwave, Perbandingan Massa Kering Terhadap Jumlah Pelarut Etil Asetat

Tannins are phenolic compounds with considerable abundance in nature. In this study, the extraction of Indian gooseberry fruit was performed using Microwave Assisted Extraction (MAE) method with ethyl acetate as solvent. Two grams of Indian gooseberry fruit were extracted for 1 minute with variable microwave power operation (100, 180, 300, 450 and 600) W. The experiment is continued at the power that gave the highest yield of tannin with variable ratio sample to solvent (1/10, 1/20, 1/30, 1/40 and 1/50) g/mL. Total tannins in the extract were analyzed using UV-Vis Spectroscopy method to find the yield of tannin. Functional groups that were contained in the extract were analyzed using Fourier-Transform Infrared Spectroscopy (FTIR) method. The results of this study indicate that the extract contains tannins in qualitative tests with gelatin and FeCl3 as well as in FTIR analysis. The highest yield of tannin was 36.86 mg/g which was obtained under conditions of power 100 W and ratio sample with ethyl acetate 1/50 g/mL.

On Super Strong ETH

Multiple known algorithmic paradigms (backtracking, local search and the polynomial method) only yield a 2n(1-1/O(k)) time algorithm for k-SAT in the worst case. For this reason, it has been hypothesized that the worst-case k-SAT problem cannot be solved in 2n(1-f(k)/k) time for any unbounded function f. This hypothesis has been called the "Super-Strong ETH", modelled after the ETH and the Strong ETH. It has also been hypothesized that k-SAT is hard to solve for randomly chosen instances near the "critical threshold", where the clause-to-variable ratio is such that randomly chosen instances are satisfiable with probability 1/2. We give a randomized algorithm which refutes the Super-Strong ETH for the case of random k-SAT and planted k-SAT for any clause-to-variable ratio. For example, given any random k-SAT instance F with n variables and m clauses, our algorithm decides satisfiability for F in 2n(1-c*log(k)/k) time with high probability (over the choice of the formula and the randomness of the algorithm). It turns out that a well-known algorithm from the literature on SAT algorithms does the job: the PPZ algorithm of Paturi, Pudlak, and Zane (1999). The Unique k-SAT problem is the special case where there is at most one satisfying assignment. Improving prior reductions, we show that the Super-Strong ETHs for Unique k-SAT and k-SAT are equivalent. More precisely, we show the time complexities of Unique k-SAT and k-SAT are very tightly correlated: if Unique k-SAT is in 2n(1-f(k)/k) time for an unbounded f, then k-SAT is in 2n(1-f(k)/(2k)) time.

Exploration of Hard to Solve 3-sat Problems

We designed and implemented an efficient tough random symmetric 3-SAT generator and propose two deterministic algorithms that efficiently generate 3-SAT instances with a unique solution. We quantify the first algorithms hardness in terms of CPU time, numbers of restarts, decisions, propagations, conflicts and conflicted literals that occur when a solver tries to solve 3-SAT instances. In this experiment, the clause variable ratio was chosen to be around the conventional critical phase transition number 4.24. The experiment shows that instances generated by our generator are significantly harder than instances generated by the Tough K-SAT generator. The two deterministic algorithms generate 3-SAT instances with the number of clauses scaling as 4n, where n is the number of variables, and (n+6), respectively. By combining these two algorithms along with a simple padding algorithm, we prove a hybrid algorithm that can generate n-variable instances with the number of clauses that scale between (n+6) and 7n(n-1)(n-2). Overall, all proposed SAT generators seek to explore unique difficult to solve SAT problems.