Fusion of soft computing and hard computing in industrial applications: an overview

Soft computing (SC) is an emerging collection of methodologies which aims to exploit tolerance for imprecision, uncertainty, and partial truth to achieve robustness, tractability, and low total cost. It differs from conventional hard computing (HC) in the sense that, unlike hard computing, it is strongly based on intuition or subjectivity. Therefore, soft computing provides an attractive opportunity to represent the ambiguity in human thinking with real life uncertainty. Fuzzy logic (FL), neural networks (NN), and genetic algorithms (GA) are the core methodologies of soft computing. However, FL, NN, and GA should not be viewed as competing with each other, but synergistic and complementary instead. Considering the number of available journal and conference papers on various combinations of these three methods, it is easy to conclude that the fusion of individual soft computing methodologies has already been advantageous in numerous applications. On the other hand, hard computing solutions are usually more straightforward to analyze; their behavior and stability are more predictable; and, the computational burden of algorithms is typically either low or moderate. These characteristics. are particularly important in real-time applications. Thus, it is natural to see SC and HC as potentially complementary methodologies. Novel combinations of different methods are needed when developing high-performance, cost-effective, and safe products for the demanding global market. We present an overview of applications in which the fusion of soft computing and hard computing has provided innovative solutions for challenging real-world problems. A carefully selected list of references is considered with evaluative discussions and conclusions.     

An application of Trefftz method to the sensitivity analysis of two-dimensional potential problem

This paper presents a new formulation for the sensitivity analysis with the help of the Trefftz boundary-type solution procedure. Direct differentiation of the expressions of the field variables leads to the expressions of the sensitivities. Since the field variables are approximated by linear combination of regular T-complete functions, the analytical expressions of the sensitivities are also regular. Sensitivity analysis schemes with respect to variations of dimensions of the object and boundary conditions are explained in detail. Two-dimensional potential problems in the bounded region are considered as a numerical example in order to confirm its validity.     

Fundamental and clinical studies on tazobactam/piperacillin in the pediatric field

The incidence of hip fractures worldwide is expected to almost quadruple in the next 60 years. Increased cost-containment pressures will focus attention not only on improvements in hip fracture treatment but also on prevention. Three approaches that can prevent hip fractures--preventing falls, preventing and treating bone fragility, and using external hip protectors--are reviewed. Although it is impossible to prevent all hip fractures, these methods may significantly reduce the annual incidence of these fractures.     

Switching characteristics and maximum repetitive frequency ofInGaAsP/InP bistable injection lasers

Switching characteristics of nonuniformly pumped InGaAsP/InP buried-heterostructure bistable lasers are investigated both experimentally and theoretically. The automatic turn-on phenomenon, which is a random process, was observed. For repetitive operation, turn-on delay time and the necessary duration of the switch-off pulse practically limited the maximum repetitive frequency. For switch-on, triggering the saturable absorption region is more effective. For reducing the minimum switch-off pulse width, either higher doping of reverse biasing at the absorption region is recommended. The tradeoff of OFF pulse width with threshold current, and stable operation are discussed. With some improvements in device parameters, bistable operation at a repetitive frequency over 1 GHz is expected     

Crystallization of sodium digermanate,Na2Ge2O5, from Na2O-GeO2 glasses

Na₂O-GeO₂ glasses containing 25～35 mole% Na₂O can be crystallized to give a new sodium germanate crystal together with Na₄Ge₉O₂₀, Na₂GeO₃ and/or Na₂Ge₄O₉ crystals. The new crystal is obtained as a principal crystallization product from the glass containing 33.3 mole% Na₂O, and is given a composition of Na₂Ge₂O₅. This sodium digermanate crystal is monoclinic with lattice parameters; a₀ = 8.421, b₀ = 4.962, c₀ = 12.67 Å and β = 103.5°, and isostructural with β-Na₂Si₂O₅. It is shown that the crystal is thermodynamically metastable.     

Finite deflection and postbuckling behavior of heated rectangular plates with temperature-dependent properties

Finite deflections and postbuckling behaviors of heated rectangular elastic plates are analyzed. Governing field equations and admissible boundary conditions are derived by variational principles for an elastic material with thermal effects. Temperature-dependent mechanical and thermal properties of plate are considered and their effect on the deflection is discussed. Numerical results are shown for two kinds of boundary conditions and temperature distributions.     

Hydride Anion Substitution Boosts Thermoelectric Performance of Polycrystalline SrTiO3 via Simultaneous Realization of Reduced Thermal Conductivity and High Electronic Conductivity

The development of environmentally benign thermoelectric materials with high energy conversion efficiency (ZT) continues to be a long-standing challenge. So far, high ZT has been achieved using heavy elements to reduce lattice thermal conductivity (κ_lat). However, it is not preferred to use such elements because of their environmental load and high material cost. Here a new approach utilizing hydride anion (H⁻) substitution to oxide ion is proposed for ZT enhancement in thermoelectric oxide SrTiO₃ bulk polycrystals. Light element H⁻ substitution largely reduces κ_lat from 8.2 W/(mK) of SrTiO₃ to 3.5 W/(mK) for SrTiO_3−xH_x with x = 0.216. The mass difference effect on phonon scattering is small in the SrTiO_3−xH_x, while local structure distortion arising from the distributed Ti−(O,H) bond lengths strongly enhances phonon scattering. The polycrystalline SrTiO_3−xH_x shows high electronic conductivity comparable to La-doped SrTiO₃ single crystal because the H⁻ substitution does not form a grain boundary potential barrier and thus suppresses electron scattering. As a consequence, SrTiO_3−xH_x bulk exhibits maximum ZT = 0.11 at room temperature and the ZT value increases continuously up to 0.22 at T = 657 K. The H⁻ substitution idea offers a new approach for ZT enhancement in thermoelectric materials without utilizing heavy elements.     

自动泊车轨迹生成方法的研究

轮式移动机器人是机器人学的重要分支,广泛地应用于消防,军事等领域.轮式移动机器人属于非完整约束系统,也是典型的强非线性系统,一般的控制理论很难能够适用.根据重复变换法对轮式移动机器人自动泊车轨迹的生成作了尝试,通过移动机器人的两驱动轮的9种可能的微小移动组合,利用顺运动学计算出与其对应机器人的位置和姿态,选取最优解,实现了机器人在障碍及非障碍环境下的自动泊车,对移动机器人优化路径,提高姿态性能,通过仿真证明了算法的可行性,生成的泊车轨迹同人操纵下泊车的轨迹非常相似.     

Structure and physical properties of biaxially stretched polyethylene terephthalate sheet after heat-setting

The consumption of hot-fillable poly(ethylene terephthalate) bottles is extremely large and is still increasing in Japan. This type of bottle is generally manufactured by the heat-set method using hot molds after stretch-blow molding. In this study, the method is simulated using a setting application in which sheets can be stretched constraining their sizes on a hot aluminum block. The crystallinities of the sheets are found to depend on the thermal history, i.e., the duration and temperature of the heat-set cycle. Heat-setting mitigates thermal-shrinkage of the sheets which is due to the increase in crystallinity or in the tense segments in the amorphous region. The structure of the heat-set sheet varies depending on the original stretched sheet. For a sample of low draw ratio, the crystallinity does not increase because of the heat-set. For a sample of medium draw ratio, the crystallinity increases greatly and the tense segments in the amorphous region also increase because of heat-set. For a sample of high draw ratio, the crystallinity increases a little but the numbers of the crystallite and tense segments in the amorphous region do not change with the heat-set.