Takes the smart home system as the research object, establishes the relevant model through the Multi-Agent theory, and uses the Value Decomposition Networks (VDN) as the model algorithm to optimize the Q function. Based on this, it is proposed to establish the rules database and knowledge database of each Agent in the smart home, and systematically open the BDI (Belief-Demand-Iintention) set of each Agent, so as to quantitatively analyze and optimize the use utility of the smart home from philosophical logic to income modeling.

Deep Feedforward Sequential Memory Network (DFSMN) is a powerful acoustic model in terms of recognition accuracy. It alleviates the gradient vanishing problem by introducing skip connections between memory blocks in adjacent layers. However, we find it is still a challenging task to optimize the neural networks when training very deep DFSMNs and simply stacking more layers can not lead to better neural networks. Residual learning is an efficient method to help neural networks converge easier and faster when building very deep structures. A novel network architecture named gated residual DFSMN (GR-DFSMN) is proposed. It introduces additional gate controlled shortcut paths from lower DFSMN blocks for efficient training of networks with very deep DFSMN structures. Experimental results have shown that GR-DFSMN can outperform the original DFSMN when training very deep models. In the 1000 hours English Librispeech task, GR-DFSMN Mono-Phone CTC model achieves a 0.7% absolute improvement compared to the original DFSMN Mono-Phone CTC model.

In the process of developing and designing new household appliances, the interface design has to go through many discussions and reviews from "design draft" to "sample presentation". With more and more attention paid to user experience, it is necessary to consider the subjective feelings of users reading interface information. However, the design reference specification for character size for kitchen appliance products has not been established yet, and the differences in age, vision, etc. among designers, developers and review experts should not be neglected, thus, there always exist many controversies in the design for character size during the process of product design and development. Considering the different usage scenarios of common household appliances in the kitchen and the relevant elements of interface design, the usability testing scheme of different character sizes was studied, and based on the test results, it provided a reference for the design of character size in enterprise interface design.

The wide implementation of home care model stimulates the demand for age-appropriate design of supporting products in home space. As an essential functional product in home care, kitchen utensils have great potential for aging design. However, at present, the research and case practice of kitchen utensils are very scarce. Based on the above needs and problems, first of all, the current pension model and suitable for aging design were analyzed, and the inclusive design method was determined to study the suitable kitchen for the elderly under the home pension model. Secondly, the physiological and psychological characteristics, living conditions and usage habits of elderly users were analyzed in combination with the home-based care model, and the variable factors of elderly differences were divided from six inclusive levels of health, emotion, habit, region, economy and learning. Finally, the case of kitchen utensils was developed according to different variable factors, and the scientific results of the study were verified by user feedback, which provided theoretical and practical reference for relevant aging design and research.

The odor on clothing is a widespread problem with social, ecological and environmental consequences, which is influenced by lots of variables and processes through whole clothing lifecycle. This review focuses on the biological and chemical process of microorganisms, metabolites and odor volatiles, reveals the impacts of human body, bacteria and metabolites, washing machine on the production and composition of odor. Moreover the possible ways of odor removal are also discussed.

In order to investigate the biological pollution in the indoor environment over Beijing in spring, the indoor dust samples of 32 households were sampled for 5 weeks from March to April 2017. The concentrations of allergens and microorganisms were detected by enzyme-linked immunosorbent assay and pour plate method, respectively, and the effects of feeding pets, furniture usage, and environmental temperature and humidity on the biological concentrations were discussed. The results showed that from March to April 2017, the concentration of Der f1 allergen in the indoor environment of Beijing was significantly higher than that of Der p1 (P<0.001), with the mean values of 74.91 ng·g-1 and 13.45 ng·g-1, respectively. The bacterial concentration was significantly higher than the fungal concentration (P<0.001), with the mean values of 3.06×106 CFU·g-1 and 5.77×103 CFU·g-1. The correlation analysis showed that the age of the user of the bed was significantly negatively correlated with the bacterial concentration (P<0.01), the temperature was positively correlated with the bacterial concentration and fungal concentration (P<0.05), and there was a positive interaction between bacteria and fungi (P<0.05). Other factors have no correlation with the concentration of allergens and microorganisms. The study shows that the main biological pollutants in the residential environment in Beijing are the dust mite allergen Der f1 and bacteria, and temperature has an effect on the concentration of microorganisms.

The main factors affecting the change of indoor formaldehyde concentration are analyzed through the actual measurement of formaldehyde concentration, furniture loading rates, and environmental factors for the newly residential buildings which renovated less than three months. On this basis, the release process of formaldehyde in wood-based panel is studied by using the imitation home environment test chamber, and the relationship is analyzed between the wood-based panel exposed rates and release concentration. The formaldehyde release law curve of wood-based panel is derived, which provides a theoretical basis for the selection of standard pollutants and the initial concentration of pollution in the evaluation of formaldehyde purification performance of air cleaner in the home environment.

In order to construct the energy efficiency grade standard for disinfecting tableware cabinet, 140 sets of energy efficiency data were analyzed and studied. First, it is classified according to the two disinfection methods of electric heating (high temperature) and combination, and then it is classified according the three compartment structures of single disinfection room, multi-disinfection room and combination of disinfection and cleaning and drying room. According to the proportion of 10%, 50%, 30% and 10%, all test data were divided into I-level energy efficiency, II-level energy efficiency, III-level energy efficiency and unqualified. The results show that the limit value of the electric heating (high temperature) disinfection method is higher than that of the combined disinfection method, and the limit value of the single disinfection compartment, the multi-disinfection compartment, and the combination of disinfection and cleaning and drying compartments increase sequentially. Research shows that there is still a lot of room for development in energy saving and emission reduction of disinfecting tableware cabinet. The introduction of energy efficiency grade standard will definitely promote the improvement of energy efficiency grades and promote the quality improvement of energy conservation and emission reduction in the industry.

Overflow disinfection for drinking water, especially for high flow water treatment, mainly uses mercury lamp, and UVC-LED as sterilization light source is mainly used in low flow water treatment equipment. With the continuous breakthrough of UVC-LED lamp bead technology, high flow water treatment equipment is also approaching to UVC-LED. Introduces a theoretical model of UVC-LED overflow disinfection device for drinking water, which realizes the sterilization of large flow disinfection for drinking water, through the continuous sterilization of module sterilization chamber. According to the analysis of optical simulation results, the theoretical flow rate of a single module sterilization cavity can reach 6 L/min.

For carbon peaking and carbon neutrality goals, the parallel-flow microchannel heat exchanger applied to small refrigeration system has become a research hotspot, which is a favorable substitution of the original copper heat exchanger. Review on frosting of the microchannel heat exchanger. Firstly, the conventional horizontal-fin configuration and some improvement schemes are introduced. In particular, the vertical-fin microchannel heat exchanger designed for the frosting condition is described. Then, numerical frosting models for the microchannel heat exchanger are analyzed, and the existing experimental researches are summarized from four aspects, i.e., substitution of the fin-tube heat exchanger, effects of environmental conditions, structural parameters and surface coating. For the popularization and application in products, it is necessary to optimize and innovate in structure, develop effective coating to retard frosting, and employ other anti-frosting technologies in the future. Meanwhile, it is also essential to develop an accurate frosting model as well as a complete design process for the microchannel heat exchanger.

Frosting is widely seen in nature and industry fields, and always plays negative effect. To accurate predict and analyze the gravity effect on the frosting process, frosting experiments at micro scale on horizontal, vertical and inverted cold plates under natural convection are carried out, with the surface temperature set at -25℃ and -15℃. The results show the droplet condensation and coalescence, the solidified liquid tip-growth and the frost layer growth stages end within 220 s with the frost thickness less than 450×10-6 m. When the gravity direction is consistent with the direction of dendrites growth, the gravity effect promotes the dendrites growth, but also causes the formation of large droplets and falling of dendrites. At the surface temperature of -15℃, the maximum diameter of droplets of the inverted cold plate formed in the droplet condensation and coalescence stage reaches 361.56×10-6 m. The periodic reverse melting and sudden falling of dendrites in the frost layer full growth stage lead to the sudden decrease and increase of frost thickness and fluctuation of the frost layer surface roughness. The difference between the peak and the trough of the roughness curve of the inverted cold plate at the surface temperature of -25℃ reaches 68.68×10-6 m. Contributions of this study could be used for predicting the specific frost characteristics on the surface of heat exchangers.

In order to reduce the pipeline vibration and noise in the process of air conditioning defrosting and improve the capacity of air conditioning heating cycle, the control technology of defrosting is experimentally studied. Firstly, the single factor tests of each actuator of air conditioner such as indoor fan, four-way valve, compressor and outdoor fan are carried out, determined the impact of each actuator on the air conditioning system. Then, the actuators are jointly controlled to form an optimized program, which is compared with the original program. Experiments show that the optimized defrosting program can reduce the high and low pressure difference by 0.061 MPa and the pipeline vibration and noise are effectively reduced when the four-way valve is reversing. The optimized scheme can also improve the heating capacity 134 W and energy efficiency ratio, which is helpful to improve the heating comfort of users. The research results have guiding significance for the control strategy of defrosting.

Multi-channel range hood can improve the smoking effect by adding upper and lower smoking ports, and the concept of large air volume and high suction force currently promoted by the market also makes the noise during use of range hoods an urgent problem to be solved. Computer Fluid Dynamics (CFD) plays an important role in the design of range hood, which is used to simulate and analyze the flow field of three-dimensional structure model to guide structural optimization and production. An optimized structure of the front air duct of a multi-channel range hood is designed, and a liner panel is added to the upper smoking port, aiming at enhancing the smoking effect and reducing the noise level. The numerical simulation method is used to compare and analyze the multi-channel range hood before and after adding the liner panel. It can be found that after adding the liner panel, the vortex at the upper inlet is reduced, the upper and lower intake air distribution ratio is more reasonable, the gas flow efficiency is higher, and the smoking effect is improved. At the same time, after the test of the range hood prototype, it was found that the whole smoking effect was better after the liner panel was added, the smoke flow leakage was less, and the noise level of the whole machine decreased by about 1 dB(A).

Under the background of the formal entry into force of the Kigali Amendment, R290, as a low-GWP refrigerant, is expected to play an important role in the field of refriger ant substitution for air conditioners in the future. The usage amount of air conditioners in China is huge, and the reasonable formulation of energy efficiency standards is significant in promoting the technological progress of the equipment manufacturing industry. First of all, the energy efficiency standards of the existing air conditioners are summarized, and then the energy efficiency grade of the air conditioners is predicted due to method of thermodynamic perfectibility and trend extrapolation, based on the R290 refrigeration cycle. The results show that the thermodynamic perfectibility and energy efficiency ratio increase with the decrease of the temperature difference at the pinch point and the increase of isentropic efficiency. The future thermodynamic perfectibility and energy efficiency are obtained corresponding to different energy efficiency grades, in which the energy efficiency range of the first class of single-cooled room air conditioners is between 6.1 and 6.2 with the rated cooling capacity of 4500 W or less in 2025, and that of heat pump room air conditioners is between 5.3 and 5.4.

In order to realize the minimization of the drum washing machine, the feasibility of replacing the cast aluminum material with fiber-reinforced thermoplastic composite material for the pulley was analyzed through CAE simulation calculation. In the analysis process, PP+50% GF plastic was selected as the substitute material. After the preliminary structural design, finite element model establishment, and calculation boundary and working conditions were determined, the maximum deformation and stress were simulated and calculated, and the structural design was optimized according to the calculation results. The final calculation results show that the deformation and stress of the composite material pulley meet the standard requirements, and the weight reduction of 14.9% and cost reduction of 20% can be realized. The replacement is feasible.

The national mandatory standard GB 12021.9-2021 "Minimum allowable values of energy efficiency and energy efficiency grade of electric fan" has been released and will be implemented, the standard adds the type of "wind gathering fans" and puts forward new technical requirements for the energy efficiency of such fans. It introduces the characteristics and principles of concentrated fan, analyzes the factors affecting its air volume, and interprets the air volume test method and energy efficiency calculation method of concentrated fan. Make readers have a more comprehensive understanding of the new energy efficiency standards for electric fans, and provide reference for relevant design and development personnel.

The flow field structure of an integrated cooking appliance fan outlet and exhaust pipe is analyzed by three-dimensional numerical simulation. According to the analysis results of model A numerical simulations and experiments, improved models, which involves double inlet, fan curve and direction of export are obtained. The comparison of numerical and experimental results for the original model A and improved model B, C, D shows that the performance of the improved model D is higher than the original model A. The results show that air flow on left side is increased by 2.49 m3/min, and the noise level is only increased by 0.24 dB(A). The air flow on right side is increased by 1.18 m3/min, and the noise level is decreased by 0.30 dB(A). The air flow difference on both sides is 0.39 m3/min. So the air flow uniformity of model D is improved obviously.

The method of combining modal analysis and topology optimization is used to design the motor bracket of the window air conditioner, so that its natural frequency can meet the vibration reduction requirements, and the weight of the motor bracket can be reduced to the greatest extent. First, ANSYS is used to conduct a modal simulation analysis of the motor bracket, and then B&K equipment is used to conduct a modal test of the motor bracket to check the boundary conditions of the simulation model. On this basis, the topology optimization of the motor bracket is carried out, the natural frequency is set as the objective function, and the weight reduction percentage is set as the constraint condition. The result of the final optimization is that the natural frequency of the motor bracket is increased by 3 Hz, avoiding the rotation frequency of the motor, and the weight of the motor bracket is reduced by 14%.

For the safe use of the water storage electrical water heater in the case of poor grounding, a class II electrical water heater using PTC heating elements is proposed, which is independent of the household electrical situation, and can work without ground wire without worrying about the abnormal ground wire. Through the targeted design of the insulation part of PTC heating elements, the requirements for class II appliances in the national standard are met. The leakage current is lower than 41% of the national standard value, and the electrical strength is higher than the national standard value, with high safety. And the double-layer PTC chip heater structure is designed, the heat transfer of the heating element is simulated and analyzed, the heat transfer factors are found. By improving the heat transfer path, reduce thermal resistance, the power of the PTC heater is effectively enhanced. The experimental data indicate that the power of the double-layer PTC heater is increased to 156% of that of the single-layer PTC heater under the condition that the convective heat exchange area with water is unchanged. The research on insulation and power improvement of PTC heating elements provides a reference for the future application of PTC heating elements in class II electrical water heaters.

The standardization of theory and technical methods is the key to the user experience practice in enterprises. However, the user experience standards existing are not systematic, affecting the practical effect. Therefore, it is necessary to build a product user experience standard system in company of household appliances to guide the practice. A practical framework of user experience standard system for household appliances is constructed for the first time, under the guidance of the national standard requirements, widely refering to successful practices on home appliance and ergonomics standard system existing. The construction of the system has gone through four stages of demand analysis, investigation, structuring and entity integration. This system is an important supplement to the standard system of household appliances. It promotes the comprehensive development of standardization, and helps to improve the specialization of user experience continuously.

EMC is an important quality indication of household appliances. According to the data of the EMC testing laboratories for household appliances accredited by the China National Accreditation Service for Conformity Assessment (CNAS), this paper analyzes the commonly used testing methods and development status of the EMC laboratories in China , analyzes the requirements for laboratory accreditation in this field, summarizes the common technical problems such as method validation effectiveness, equipment calibration, test site confirmation, testing standardization, etc., and gives some suggestions on the development of the EMC Testing Laboratory of household appliances in China.