A DESIGN OF MULTILOOP PID CONTROLLERS WITH A NEURAL‐NET BASED DECOUPLER

In process industries, PID control schemes have been widely used due to their simple structures and easiness of comprehending the physical meanings of control parameters. However, the good control performance cannot be obtained by simply using PID controlschemes, since most processes are considered as nonlinear multivariable systems with mutual interactions. In this paper, a design method of multiloop PID controllers neural‐net based decoupler is proposed for nonlinear multivariable systems with mutual interactions. The proposed method consists of a decoupler given by the sum of a static decoupler and a neural‐net based decoupler, and multi‐loop PID controllers. Finally, the effectiveness of the proposed control scheme is evaluated on the simulation examples.     

Microstructure and refining performance of an Al-5Ti-0.25C refiner before and after equal-channel angular pressing

Refining experiments were conducted to evaluate the grain refining performance of an Al-5Ti-0.25C refiner before and after equal-channel angular pressing (ECAP) with the use of a high-purity Al. The results show that the Al-5Ti-0.25C refiner has remarkable and stable grain refining performance when the holding times are within 5 to 30 minutes and the melt temperatures are within 1003 to 1073 K. Furthermore, some Al-5Ti-0.25C refiner samples were subjected to severe plastic deformation by using the ECAP technique at 298 K. It was found that Al₃Ti and TiC particles were significantly fragmented and their mean sizes were decreased to 10 and 1.08 μm, respectively, and the Al-5Ti-0.25C refiner appeared to have a double grain refining effect in comparison with that of before ECAP. It is also testified that the Vickers microhardness (Hv) value of the pure Al samples refined by the Al-5Ti-0.25C refiner after ECAP processing has a significant increment than that of before ECAP processing. It is concluded that the Al-5Ti-0.25C refiner with ECAP technique has a very useful practical application in refining industrial Al alloys.     

6-Axis control cutting of overhanging curved grooves by means of non-rotational tool with application of ultrasonic vibrations

This paper presents a new machining method that efficiently cuts overhanging curve grooves on wall surfaces without causing a collision between the tool and the workpiece. It also describes the development of software for 6-axis control grooving and the effect of applied ultrasonic vibrations (USV) in cutting overhanging grooves (OHG). In general, rotational tools are used to produce grooves, thus resulting in long circular arc segments at the cutting end points, as well as placing restrictions on the manufacture of grooves with continuous change in curvature, while ensuring that they do not overshoot the side clearance angle of the cutting edge with the groove. The study aims at machining OHGs presently impossible to machine by conventional methods. From the experimental results, it was found that the new machining method, which is 6-axis control cutting using a non-rotational tool with the application of USV, is capable of cutting an OHG on wall surfaces correctly.     

Impact strength improvement of polystyrene by dispersion of rigid particulate

We have discovered that the impact strength of polystyrene is increased by the addition of rigid particles several microns in diameter and at concentrations of 0.01 ∼ 1 wt%. As examples, we used barium sulfate particles and crosslinked polystyrene beads. From the observation of real-time deformation of polystyrene incorporating the rigid particles, and from finite element analysis, it is clear that the impact improvement mechanism is related to the formation of voids or peeling layers, and successive extension of crazes from the voids or peeling layers.     

Shape memory behavior of poly(methyl methacrylate)-graft-poly(ethylene glycol) copolymers

This paper describes a shape memory behavior of graft copolymers poly(methyl methacrylate)-graft-poly(ethylene glycol) (PMMA-g-PEG). In shape memory test, the sample was deformed from its original shape to a temporary shape above glass transition temperature (T_g), cooled below T_g to fix the temporary shape, and subsequently heated above T_g for spontaneous recovery to the original shape. By grafting PEG onto PMMA backbone, shape memory ability was drastically enhanced than PMMA homopolymer. The shape recovery ratio was decreased with the increase in the shape deformation temperature. With considering a good miscibility of backbone and side chain in PMMA-g-PEG, this shape memory ability may be related to a physically cross-linked network structure by chain entanglement of the comb-like graft copolymer. Stress relaxation measurements were investigated in order to confirm the effect of the graft chains on the shape memory behavior.     

Cr concentration dependence of overestimation of long term creep life in strength enhanced high Cr ferritic steels

Creep rupture data and microstructural degradation during aging of high Cr ferritic boiler steels with enhanced creep strength have been studied with special attention to prediction of long term creep rupture life. Tempered lath martensite structure in the high Cr ferritic steels remains unchanged during short term aging, whereas static recovery of the lath martensite structure proceeds when diffusion distance during aging becomes sufficiently long as is the case in long term creep. The static recovery brings about premature failure in long term creep and decreases in apparent activation energy for creep life. The decrease in activation energy is responsible for overestimation of rupture life reported in strength enhanced high Cr ferritic steels. The boundary from a short term region with high activation energy Q_H to a long term region with low activation energy Q_L moves towards longer time with decreasing Cr concentration. The difference in activation energy (Q_H − Q_L) primarily determines the extent of overestimation of rupture life predicted from short term data. In general, the extent of overestimation is less serious at 9%Cr as compared to 12%Cr.     

Effects of peel angle on peel force of adhesive tape from soft adherend

In the case of the peeling of adhesive tapes from soft adherends, the contributions of the compressive force at the adhered portion as well as the larger deformation of adherend have essential roles in determining the peeling properties. In this paper, the peel force of an adhesive tape from a soft adherend has been measured to understand the peeling mechanism, which is greatly affected by the peel angle. A commercially available pressure-sensitive adhesive was used as the tape, and a cross-linked polydimethylsiloxane (PDMS) was used as the soft adherend. The purpose of this study is to clarify the effects of the peel angle on the peel behavior of this system at room temperature under different material specifications and different experimental conditions. The factors that affect the peel force of the PDMS adherend included the degree of cross-linking in PDMS, the thickness of PDMS, peel angle, and peel velocity. Two characteristic peel patterns were observed, which depended on the material specifications and different experimental conditions. The peel mechanism was discussed in terms of the deformation of the adherend.     

Japanese New-Product Development Techniques

Yasuhiro Monden The Japanese automotive industry has already become a by-word for lean production efficiency. Recently attention has shifted to its new-product development activities, and in particular to the techniques of simultaneous engineering that generate superior performance when contrasted with the traditional linear and sequential approaches. The paper probes the cost management system that underpins the Japanese automotive product-development system, enabling a network of producers and suppliers to work cooperatively and in parallel through successive prototyping stages of the process. The core concept is the iterative development of a 'target cost' for each component of the process.     

PHS roaming signaling protocol architecture toward global mobilitynetwork

The network for supporting the global personal communication is called the global mobility network (GLOMONET), where global mobility is guaranteed by coordination between intelligent networks (INs). This paper describes the implementation of a roaming signaling protocol for the personal handy-phone system (PHS) GLOMONET, clarifying the concepts of the PHS architecture regarding the GLOMONET. The PHS is a more economical personal communication system than existing cellular systems, by introducing the concept that the PHS service is provided by the most effective use of the existing ISDN and IN functions, where the majority of network functions to provide ISDN services are commonly used for functions for PHS service provision. The PHS mobility function realized by the IN guarantees flexible and effective roaming service provision for the globalization of future personal communication. The proposed PHS signaling protocol architecture is based on the intelligent network capability set 2 (IN CS2) defined by the International Telecommunication Union-Telecommunication Standardization Sector (ITU-T) Study Group 11 and a visitor location register (VLR) database scheme with efficient signal transfer in the GLOMONET. The PHS specific roaming signaling protocol is defined by the service-independent IN application protocol (INAP). The proposed PHS concepts and roaming signaling protocol were reflected to the national telecommunications standards in the Telecommunication Technical Committee (TTC) and standards in the PHS-memorandum of understanding (MoU)     

Prader-Willi syndrome with elevated follicle stimulating hormone levels and diabetes mellitus

A 21 -year-old man with Prader-Willi syndrome (PWS) was hospitalized due to hyperglycemia. After diet therapy and transient insulin administration, his blood glucose levels improved. Based on the fact that his urinary C-peptide levels increased, the diabetes mellitus may have been due to insulin resistance with obesity. In addition, his testes had become atrophied. Testosterone levels remained low even after human chorionic gonadotropin (HCG) administration. Luteinizing hormone (LH) levels were also low after LH releasing hormone (LHRH) administration. The LH response increased slightly after daily LHRH administration, indicating hypothalamic hypogonadism. Follicle stimulating hormone (FSH) levels were, however, high and increased after LHRH administration. The selective FSH elevation may have been due to the accompanying idiopathic oligospermia.