A human‐like numerical technique for design of engineering systems

Because of the necessity for considering various creative and engineering design criteria, optimal design of an engineering system results in a highly‐constrained multi‐objective optimization problem. Major numerical approaches to such optimal design are to force the problem into a single objective function by introducing unjustifiable additional parameters and solve it using a single‐objective optimization method. Due to its difference from human design in process, the resulting design often becomes completely different from that by a human designer. This paper presents a novel numerical design approach, which resembles the human design process. Similar to the human design process, the approach consists of two steps: (1) search for the solution space of the highly‐constrained multi‐objective optimization problem and (2) derivation of a final design solution from the solution space. Multi‐objective gradient‐based method with Lagrangian multipliers (MOGM‐LM) and centre‐of‐gravity method (CoGM) are further proposed as numerical methods for each step. The proposed approach was first applied to problems with test functions where the exact solutions are known, and results demonstrate that the proposed approach can find robust solutions, which cannot be found by conventional numerical design approaches. The approach was then applied to two practical design problems. Successful design in both the examples concludes that the proposed approach can be used for various design problems that involve both the creative and engineering design criteria. Copyright © 2005 John Wiley & Sons, Ltd.     

Intercomparison of ocean colour band-ratio algorithms for chlorophyll concentration in the Subtropical Front east of New Zealand

This study intercompared the performance of eight band-ratio chlorophyll-a algorithms which together can be used to process measurements from the ocean colour satellite sensors CZCS, OCTS, SeaWiFS, MODIS, MERIS, and GLI. The study area included Subtropical, Subtropical Front and Subantarctic waters east of New Zealand, and Case 1 waters of the New Zealand northeast continental shelf. Over 170 co-incident measurements of spectral normalised water-leaving radiance and near-surface concentration of chlorophyll-a were made on nine research voyages between 1998 and 2000. The studentised bootstrap method was used to identify statistically significant bias in algorithm products relative to in situ measurements. The band-ratio algorithms used by CZCS, OCTS and SeaWiFS missions systematically underestimated chlorophyll-a concentration in the offshore regions by between 21% and 45%, but showed no systematic bias in the continental shelf waters. The band-ratio algorithms applicable to the MODIS and MERIS sensors had no clear bias with respect to in situ measurements in offshore waters, but had a positive bias of 20% over the continental shelf. The proposed GLI band-ratio algorithm led to estimates that were negatively biased with respect to in situ measurement offshore (− 30%), and positively biased over the continental shelf (20%). The results were consistent with unusually high values of absorption in the blue part of the spectrum (443-490 nm) compared to the green part (∼ 550 nm) by phytoplankton pigments in the offshore waters, and high chlorophyll-specific absorption over the continental shelf.     

Seismic capacity evaluation of a group of vertical U-tube heat exchanger with support frames for seismic PSA

This paper presents an evaluation of seismic capacity of a group of vertical U-tube type heat exchangers (HXs) with support frames to contribute to refinement of seismic capacity data for seismic Probabilistic Safety Assessment (PSA) in Japan. According to usual practice of seismic PSAs, capacity of component is represented as a log-normally distributed random variable defined by a median and logarithmic standard deviations (LSDs), which represent inherent randomness about the median, β_r, and uncertainty in the median due to lack of knowledge, β_u. Using design specifications of four HXs for residual heat removal systems of 1100 MWe BWRs, the authors evaluated a generic capacity of HXs with a LSD for uncertainty due to lack of knowledge to take into account design variability. The median capacity was evaluated by the use of a time history response analysis with a detailed model for a selected representative HX, which was extended from a model used in seismic design. The LSD for uncertainty due to lack of knowledge was evaluated with consideration of the variabilities in three influential design parameters, i.e., diameter of anchor bolt, weight of HX and position of center of gravity of HX with the detailed model and a simplified static model. The LSD for uncertainty due to randomness was determined from the variability in material property. The dominant failure mode of HXs was identified as the failure of anchor bolts of lugs mainly due to shearing stress. The capacity expressed in terms of zero period acceleration on the foundation of HX was evaluated to be 4180 Gal (4.3 g) for median, LSD for uncertainty due to randomness was 0.11 and LSD due to lack of knowledge was 0.21–0.53 depending on combination of the variabilities in design parameters to be considered.     

微量生物液体机器人分配系统的研究

本文从系统功能的角度出发，分析了广泛应用于基因研究和蛋白质研究领域的 微量液体分配系统的主要功能和主要功能模块，着重研究了系统的关键技术．并对微量液体 分配系统的发展方向和需要解决的问题提出几点看法．     

线性规划的一种并行修正松弛算法

对求解线性规划问题的松弛算法进行了修正 ,在此基础上提出了一种基于 Cluster结构的并行算法 ,分析了算法的性能 ;基于曙光— 30 0 0大规模并行计算机 ,给出了算法用于求解线性规划问题实例的实验结果 .理论分析和实验结果表明 :修正算法改进了松弛算法的实际性能 ,同时具有较好的并行性和稳定性 ,可用于求解此类大规模科学与工程规划问题的高性能计算     

Order-sorted logic programming with predicate hierarchy

Order-sorted logic has been formalized as first-order logic with sorted terms where sorts are ordered to build a hierarchy (called a sort-hierarchy). These sorted logics lead to useful expressions and inference methods for structural knowledge that ordinary first-order logic lacks. Nitta et al. pointed out that for legal reasoning a sort-hierarchy (or a sorted term) is not sufficient to describe structural knowledge for event assertions, which express facts caused at some particular time and place. The event assertions are represented by predicates with n arguments (i.e., n-ary predicates), and then a particular kind of hierarchy (called a predicate hierarchy) is built by a relationship among the predicates. To deal with such a predicate hierarchy, which is more intricate than a sort-hierarchy, Nitta et al. implemented a typed (sorted) logic programming language extended to include a hierarchy of verbal concepts (corresponding to predicates). However, the inference system lacks a theoretical foundation because its hierarchical expressions exceed the formalization of order-sorted logic. In this paper, we formalize a logic programming language with not only a sort-hierarchy but also a predicate hierarchy. This language can derive general and concrete expressions in the two kinds of hierarchies. For the hierarchical reasoning of predicates, we propose a manipulation of arguments in which surplus and missing arguments in derived predicates are eliminated and supplemented. As discussed by Allen, McDermott and Shoham in research on temporal logic and as applied by Nitta et al. to legal reasoning, if each predicate is interpreted as an event or action (not as a static property), then missing arguments should be supplemented by existential terms in the argument manipulation. Based on this, we develop a Horn clause resolution system extended to add inference rules of predicate hierarchies. With a semantic model restricted by interpreting a predicate hierarchy, the soundness and completeness of the Horn-clause resolution is proven.     

An Information Continuum Conjecture

Turing tersely mentioned a notion of ``cultural search'' while otherwise deeply engaged in the design and operations of one of the earliest computers. His idea situated the individual squarely within a collaborative intellectual environment, but did he mean to suggest this in the form of a general information system? In the same writing Turing forecast mechanizations of proofs and outlined genetical searches, much later implemented in cellular automata. The conjecture explores the networked data-information-knowledge continuum as the subject of Turing's notions of search and intelligence, using analogous models from library systems theory. Floridi's philosophy of information is posed as a potential guide to applied information services design of the Turing type. The initial problem is to identify a minimal set of assumptions from Turing's essay beyond the general context of computing. This set will form a bridge to an analogous set of principles in library systems models by eliciting supporting evidence in the literature relating the two. Finally it will be shown how Floridi's philosophy of information more fully encompasses Turing's insight in view of the conjecture.

     

Thermoelectric properties of rare earth doped SrTiO3

The thermoelectric properties of Sr_0.9R_0.1TiO₃ (R=Y, La, Sm, Gd, Dy) have been measured from room temperature to 1073 K. The electrical conductivities and Seebeck coefficients are independent of the kind of rare earth elements in the temperature range, so the figure of merits are influenced by the difference in the thermal conductivities. The thermal conductivities decrease with doping according to the rare earth atomic mass and ionic radius. Sr_0.9Dy_0.1TiO₃ shows the highest figure of merit of the investigated samples, reaching 3.84×10⁻⁴ K⁻¹ at 573 K.     

A method for aerosol particle removal by applying condensation phenomena

This paper describes an experimental study on a method of removing aerosol particles from air by condensing heated and humidified air. In the experiment, air, including aerosol particles, is circulated by a fan in a closed clean room system consisting of a closed vessel, a humidifier, two condensers, and an after-heater. The concentration of aerosol particles at the inlet of the closed vessel, the relative humidity, and the temperature in the system are measured for several humidification and condensation conditions. We find that the removal rate of aerosol particles in air increases when the mass flow rate of the condensate increases, by means of enlarging the temperature difference between the heating water in the humidifier and the cooling water in the condensers. We also show that this method is more effective when the temperature level in the humidifier is increased. The aerosol particle removal mechanism of this method is considered to be related to the generation of mist using aerosol particles as nuclei, inertia trapping, and the suction effect of condensation. © 1998 Scripta Technica. Heat Trans Jpn Res, 26(6): 398–409, 1997