Searching minimax game trees under memory space constraint

Games such as CHESS, GO and OTHELLO can be represented by minimax game trees. Among various search procedures to solve such game trees,- and SSS^* are perhaps most well known. Although it is proved that SSS^* explores only a subset of the nodes explored by-, - is commonly believed to be faster in real applications, since it requires very little memory space and hence its storage management cost is low. Contrary to this folklore, however, this paper reports, using the OTHELLO game as an example, that SSS^* is much faster than-. It is also demonstrated that SSS^* can be modified to make the required memory space controllable to some extent, while retaining the high efficiency of the original SSS^*.This research was partially supported by the Ministry of Education, Science and Culture of Japan, under a Scientific Grant-in-Aid.     

Consequences of the formation of Cooper-pairs near oxygen-deficient sites

In this investigation we consider the formation of Cooper pairs near the oxygen-deficient sites in Y-Ba-Cu-O ceramic superconductors which would give rise to an energy-dependent potential as seen by conduction charge carriers. It is shown that Cooper pairs could be formed under such conditions, resulting in a supercurrent. We use the Bogoliubov transformation technique to calculate the energy gap, the energy difference, and the transition temperature of the model superconductor using certain data obtained from previous experiments. Numerical analysis shows that the superconducting current can be explained by the presence of such oscillating Cooper pairs.     

Arnold置乱在零水印中的二次复用

为了提高水印的鲁棒性和减小对应版权信息的大小,本文提出了一种基于Arnold变换、DWT和SVD的零水印算法。该算法将载体图像进行DWT变换,对低频子带进行分块SVD;比较置乱后的最大奇异值的大小,若大于则对应位为1,否则为0;将结果与预处理过的水印做异或运算,得密钥矩阵。该矩阵为检测水印提供密钥。实验证明,本算法对图像压缩、滤波、模糊、噪声及脏图具有良好的鲁棒性。     

A functional programming approach to the specification and verification of concurrent systems

Networks of communicating processes can be viewed as networks of stream transformers and programmed in a lazy functional language. Thus the correctness of concurrent systems can be reduced to the correctness of functional programs. In this paper such correctness is proved formally in the-calculus extended with recursion equations for functional programs. The-calculus is chosen since it allows the definition of properties by least fixed points (induction) as well as by greatest fixed points (coinduction), and since greatest fixed points are useful for formalising properties, such as fairness, of infinitely proceeding programs. Moreover, non-deterministic processes are represented as incompletely specified deterministic processes, that is, as properties of stream transformers. This method is illustrated by proving the correctness of the alternating bit protocol.     

Effect of 0.1 at.% zirconium on the cyclic oxidation resistance ofβ-NiAl

The effect of 0.1 at.% Zr (0.2 wt.% Zr) on the cyclic oxidation of hipped -NiAl was studied. Oxidation testing was performed in static air at 1100–1200 °C, using 1-hr exposure cycles for test times up to 3000 hr. The weight change versus time data were modeled with the COSP computer program to analyze and predict cyclic-oxidation behavior. Zr additions significantly change the nature of the scale-spalling process during cooling so that the oxide spalls near the oxide-air interface at a relatively low depth within the scale. Without Zr, the predominantly -Al₂O₃ scale tends to spall randomly to bare metal at relatively high effective-scale-loss rates, particularly at 1150°C and 1200°C. This leads to higher rates of Al consumption for the Zr-free aluminide and much earlier depletion of Al, leading to eventual breakaway (i.e., failure).     

Mechanical procedure for proof construction via closed terms in typed λ calculus

In this paper is presented an algorithm for constructing natural deduction proofs in the propositional intuitionistic and classical logics according to the analogy relating intuitionistic propositional formulas and natural deduction proofs, respectively, to types and terms of simple type theory. Proofs are constructed as closed terms in the simple typed calculus. The soundness and completeness of this method are proved.     

Sex pheromones of male yellowfin Baikal sculpin (Cottocomephorus grewingki): Isolation and chemical studies

Three components of the male yellowfin Baikal sculpin pheromonal signal have been isolated from urine by diethyl ether extraction, thinayer chromatography (TLC), and high-performance liquid chromatography (HPLC). Using mass spectrometry, we have identified two of them as testosterone (T) and 11-hydroxytestosterone (11HT). These steroids are synthesized in testes during full spermatogenesis, and they are excreted in male urine with milt. The third component is not a steroid. It is more likely to be a polyene alcohol (farnesol). 2Z,6E-Farnesol possesses behavioral activity.     

基于关键链优化的课程教学与实践教学契合OA绩效方法研究

作为高等教育体系中的两大主要模块,课程教学与实践教学在时间维度、逻辑维度和认知协同维度往往会存在矛盾,导致了教学质量的降低。本文从这三个维度出发,首先确定了具有普适性的教学绩效评估方法;随后根据多项目管理的关键链法提出了教学优化的具体步骤;最后以工商管理专业课程为实例根据上述教学绩效评估方法验证了教学优化的效果。     

提高地方院校信管专业学生实践能力的途径研究

为了提高地方院校信管专业的竞争能力,将实践能力和地方性特色培养融入到学校教育中,成为了现在地方院校信息管理与信息系统专业教育的重中之重。论文首先强调了信管专业学生实践能力培养的重要性。然后通过调查比较找出目前各地方院校信管专业实践教育体系存在的不足之处。最后以南通大学为例具体研究提高南通大学信管专业学生实践能力的途径。