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With the increasing speed and capacity of variable-speed rotary compressors, the problem of noise especially low and medium frequency noise in the air conditioning system which can't be solved by wrapping soundproof cotton has became more serious. In this paper, based on the noise problem of the rotor compressor with a working capacity of more than 80CC, the main frequency and the position of the noise source within 1000Hz are confirmed by simulation and experiment. Then on the base of this，the muffler and accumulator are respectively optimized and improved combining with Computer Aided Engineering (CAE) means. The final application results show that the optimized scheme can reduce noise by 6.1dB in 160Hz and 8.9dB in the frequency range of 500Hz to 800Hz, achieving good results.

Pyrroline-5-carboxylate reductase 1 (PYCR1) is an enzyme involved in cell metabolism and is upregulated in cancer. However, the correlations of PYCR1 expression with the clinicopathological features and prognosis of renal cell carcinoma (RCC) remain unclear. The purpose of this study was to identify the expression of PYCR1 and its clinical relevance in RCC patients. PYCR1 mRNA expression differences between RCC and the adjacent normal renal tissues were assessed using the Cancer Genome Atlas database (TCGA). Subsequently, the expression of PYCR1 mRNA and protein were evaluated by quantitative real-time polymerase chain reaction, Western blot, and immunochemistry using 30 paired frozen samples of RCC and the adjacent normal renal tissues. The protein expression of PYCR1 was evaluated by immunostaining formalin-fixed, paraffin-embedded sections of RCC samples from 96 patients who underwent radical nephrectomy, and its relationship with clinical features were analyzed. Nonpaired t tests were used to statistically analyze the differences between the 2 groups. Cox univariable and multivariable analyses of overall survival (OS) among RCC patients were performed. The expression of PYCR1 mRNA was significantly upregulated in RCC tissues compared to adjacent normal renal tissues in the TCGA database (P

The electromagnetic bandgap (EBG) structure, which is widely used in the microwave and millimeter-wave fields, is a kind of photonic crystal. An EBG structure with bow-tie cells having different tapered forms is presented in this paper. Furthermore, the EBG structure is optimized by using an improved particle swarm optimization algorithm. The optimal results show that the optimized EBG structure with bow-tie cells has a good stop-band performance and large relative bandwidth. The passband ripples of the EBG structure are very small and basically symmetrical. The frequency characteristic of the optimized EBG structure is found to be excellent. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

The article uses research ways of following the whole lifespan of product and enterprise's development course to research strategy of company's product design and development. It announces enterprises of different nature, enterprises at different developing stage will adopt different mode strategy. It also announces close causality between development course of company and central technology and product. The result indicated in different developing stages such as company development period, crisis predicament period, lasting steadies period, improving by payback period, issues steadies secondary period, declining go and live period, enterprise should pursue different mode product tactics of research and development such as shrinking strategy, consolidating strategy, innovation keeping forging ahead strategy. Enterprise should break regular management mode to introduce different research and development mode to promote enterprise's competitiveness effectively.

The article uses research ways of Enterprise localization and enterprise's development course to research strategy of company's product design and development. It announces at different stages for development, different kinds of enterprises will adopt product design and development policies of different modes. It also announces close causality between development course of company and central technology and product. The result indicated enterprises in leading position in market, technology and brand adopt pioneer strategy type of product research and development. These enterprise relying on the large-scale leading enterprise offering a complete set service adopts the passively duplicating type tactic of product research and development. Some enterprise in part of advantage in technology, market, management or brand adopt following up strategy of product research and development. The enterprises with relative advantage position adopt the strategy of technology applied taking optimizing services as centre in product research and development in fields of brand culture and market service.

From communication systems to biomedical systems, microstrip antennas (MSAs) are used in a broad range of applications, and this primarily due to their simplicity, conformability, low manufacturing cost, light weight, low profile, reproducibility, reliability, and ease in fabrication and integration with solid-state devices [1][2]. Recently, these attractive features have increased the applications of MSAs and stimulated greater effort to investigate their performance. In designing MSA, it is very important to determine its resonant frequencies accurately, because MSA has narrow bandwidths and can only operate effectively in the vicinity of the resonant frequency. So, a model to determine the resonant frequency is helpful in antenna designs. Several methods, varying in accuracy and computational effort, have been proposed and used to calculate the resonant frequency of rectangular MSA [3]-[13]. These methods can be broadly classified into two categories: analytical and numerical methods. Based on some fundamental simplifying physical assumptions regarding the radiation mechanism of antennas, the analytical methods are the most useful for practical design as well as providing a good intuitive explanation of the operation of MSAs. However, these methods are not suitable for many structures, in particular, if the thickness of the substrate is not very thin. The numerical methods provide accurate results but usually require tremendous computational effort and numerical procedures, resulting in roundoff errors, and may also need final experimental adjustment to the theoretical results. They suffer from a lack of computational efficiency, which in practice can restrict their usefulness due to high computational time and costs. The numerical methods also suffer from the fact that any change in the geometry, including patch shape, feeding method, addition of a cover layer, etc., requires the development of a new solution. During the last decade, artificial neural network (NN) models have been increasingly used in the design of antennas, microwave devices, and circuits due to their ability and adaptability to learn, generalization, smaller information requirement, fast real-time operation, and ease of implementation features [14][15]. Through training process, a NN model can be developed by learning from measured/simulated data. The aim of the training

This paper uses weary test, probability statistics and thermodynamics research technique to research for overall structural layout, fault cause, basic product function, barycentre distribution and thermodynamics characteristic of steamer. It is discovered jam of heating pipe is main fault reasons and distribution of heat dissipation around pot play an important part in overall structural layout. It reveals basic structural fault of revolving heating plate-type pot. The fault's reasons can be radically solved through design methods of structuralism and heat distribution of pot can also be improved by adopting method of thermodynamics analysis. The result indicates using weary test and method of probability statistics could effectively discover the fault reasons of new product. In addition, basic research on core technology of steam thermodynamics can innovatively develop new type steamer, improve working stability, barycenter stability, mobile convenience, and reduce production cost.

This paper adopts the methods of product unity identity design and refinement of brand image foundation strategy to research strategy of uniformly designing for brand image of product, external vivid marking image of product, internal nominal quality image and image characteristic of social symbolic symbol. It reveals that product unity identity design has the characteristics of symbolic, commonality, freshness and monopolization. By using this design method in practical designing, it is found that model beginning with single product image to making characteristic summary and concluding so as to be popularized to peripheral product system is benefit to implementing product unity identity plan. The result shows internal quality image of product, external marking image and social symbol image should be uniformly planed and designed so as to keep function correspondence relation of unifying internal and external, which is benefit to founding and constantly keeping vitality of product.

This article uses physical research methods and design verification methods in original driving force of enterprise development as well as development of basic resources cycle to research power, cause, and necessity and implementation strategy all concerning enterprise sustainable development. The result indicates implement of enterprise sustainable development strategy largely depends on progress in technology, innovative thinking patterns and changes of management strategy. It has been found that the adoption of constructivism design based on function and core technology principle innovation design method could reduce the consumption of materials by the greatest extent. Adopting function module combination to build product system can achieve optimization utilize of enterprise resources on operation level. Enterprise replaces the profit pattern of one-shot hardware sale by providing more human value-added services to rebuild enterprise development pattern forming connotation of enterprise sustainable development strategy. The study reveals root of implementing sustainable development and keeping brand vitality lies in implements of providing more immaterial services, strategies which enable solution to replace material products and resources cycle balanced type management strategies which advocate public t

This paper used research method to make computer network benefit community personified. Responsibilities and management ways of composition in the community were studied. Nature, manpower and public foundational resources and its assigning management mechanism dependent by the community were studied. The results indicate interior of community has primitive instinct power to pursue maximization of social value and economic benefit. Exterior has extrusive competitive force. Dual forces make it has instinct tendency with sustainable development. The results proclaim to community's competitive mechanism principle and developing driving force principle in balance between interior and external force, construct community's value system successfully, and indicate direction and goal of community developing.

In a downlink multiuser multi-input multi-output (MU-MIMO) communication system, a base station (BS) transmits to multiple mobile stations (MS) simultaneously over the same frequency band, thereby greatly increasing the channel capacity. However, in previous works, the multiuser spatial multiplexing system has no special strategies for selecting the multiuser channel. Although the exhaustive search algorithm can achieve optimal performance, its cost is large. In this paper, we propose a suboptimal user selection algorithm for the MU-MIMO system to save hardware resources and serve more users. The proposed selecting criterion bases on maximum total throughput by selecting the best channel of user. To reduce the complexity further more, we give out an iterative selection scheme. Compared with the optimal algorithm, the proposed algorithm achieves good sum capacity performance, has lower complexity, and is suitable for practical communication system. Simulation results show the performance of the proposed scheme.

Orthogonal frequency division multiplexing (OFDM) is an attractive technology for high speed data transmission wireless communication. However, OFDM has a large peak-to-average power ratio (PAPR), which means that the high requirements for precision of the linear amplifiers, and thus result to high system cost. To solve this problem, a novel partial transmit sequence (PTS) technique based on improved simulated annealing optimization (ISA-PTS) is proposed in this paper. The improved SA optimization approach is applied to search the optimal combination of phase factors, which can achieve the OFDM signals with low PAPR and reduce the computational complexity significantly. Simulations show that ISA-PTS technique provides a good compromise between PAPR reduction performance and the computational complexity.

In this paper, a fast antenna selection algorithm is proposed in wireless multiple input multiple output systems. The algorithm makes use of an efficient recursive QR factorization for selecting the sub-optimal antenna subset in terms of minimum error rate. The proposed algorithm decreases the computational complexity greatly, and improves the performance of the linear receiver. Simulation results demonstrate that the proposed antenna selection algorithm achieves excellent performance under uncorrelated and correlated channel.

One main disadvantage of MIMO-OFDM is that the signals transmitted on different antennas might exhibit a prohibitively large peak-to-average power ratio (PAPR). In this paper, a low complexity concurrent selective mapping algorithm is proposed to solve the problem. A new criterion of minimum maximum (minmax) is proposed, by which the proposed algorithm achieves much better PAPR performance. Moreover, it is proved that the conjugate symbols on two antennas have the same PAPR property with orthogonal space-time block coded (STBC). By using the characteristic, the computational complexity cost and the side information (SI) is significantly reduced compared with the concurrent SLM algorithm. Simulation results demonstrate that the performance of the proposed algorithm outperforms the conventional concurrent SLM algorithm.