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The central amygdala (CeA) consists of numerous genetically defined inhibitory neurons that control defensive and appetitive behaviors including feeding. Transcriptomic signatures of cell types and their links to function remain poorly understood. Using single-nucleus RNA sequencing, we describe nine CeA cell clusters, of which four are mostly associated with appetitive and two with aversive behaviors. To analyze the activation mechanism of appetitive CeA neurons, we characterized serotonin receptor 2a (Htr2a)–expressing neurons (CeA Htr2a ) that comprise three appetitive clusters and were previously shown to promote feeding. In vivo calcium imaging revealed that CeA Htr2a neurons are activated by fasting, the hormone ghrelin, and the presence of food. Moreover, these neurons are required for the orexigenic effects of ghrelin. Appetitive CeA neurons responsive to fasting and ghrelin project to the parabrachial nucleus (PBN) causing inhibition of target PBN neurons. These results illustrate how the transcriptomic diversification of CeA neurons relates to fasting and hormone-regulated feeding behavior.

SUMMARYThe central amygdala (CeA) consists of numerous genetically-defined inhibitory neurons that control defensive and appetitive behaviors including feeding. Transcriptomic signatures of cell types and their links to function remain poorly understood. Using single-nucleus RNA-sequencing, we describe nine CeA cell clusters, of which four are mostly associated with appetitive and two with aversive behaviors. To analyze the activation mechanism of appetitive CeA neurons, we characterized Serotonin receptor 2a (Htr2a)-expressing neurons (CeAHtr2a) that comprise three appetitive clusters and were previously shown to promote feeding. In vivo calcium imaging revealed that CeAHtr2aneurons are activated by fasting, the hormone ghrelin, and the presence of food. Moreover, these neurons are required for the orexigenic effects of ghrelin. Appetitive CeA neurons responsive to fasting and ghrelin project to the parabrachial nucleus (PBN) causing inhibition of target PBN neurons. These results illustrate how the transcriptomic diversification of CeA neurons relates to fasting and hormone-regulated feeding behavior.HighlightsTranscriptomics reveals four appetitive, two aversive and three unknown CeA clustersGhrelin and fasting activate CeAHtr2aneurons comprising three appetitive clustersGhrelin’s orexigenic effects require the activity of appetitive CeA neuronsCeA→PBN inhibition is necessary for ghrelin/fasting induced feeding

This paper proposes a dedicated outdoor air system (DOAS) with thermoelectric radiant panels (TERPs) for high-speed train cabins that prevents air quality problems and reduces operation energy consumption. The DOAS supplies cooled and dehumidified outdoor air for ventilation and the removal of latent loads. The cooling and heating loads can be accommodated using TERPs, which are suitable for use in train cabins owing to their simple structure. Moreover, the air flow at the exterior surface during train running can be used to remove rejected heat from the TERP. In this study, detailed energy simulations were conducted to evaluate the energy saving potential of the proposed system compared to the conventional variable air volume system. The results indicated that the proposed system can save 32.6% of the annual operation energy. In addition, the TERP system showed an annual COP exceeding 2.2 during 75% of its operational time.

The main objective of this research is to propose a dedicated outdoor air system assisted by a thermoelectric heat pump, and to evaluate the operating energy performance of the proposed system compared with a reference system. The proposed dedicated outdoor air system consists of an enthalpy wheel, a desiccant wheel, and the thermoelectric heat pump to condition the introduced outdoor air to provide required ventilation air to the conditioned zone at neutral temperature, while the reference system consists of a desiccant wheel, a sensible heat exchanger, a cooling coil, and a regeneration air heater. To develop an empirical model for the thermoelectric heat pump applicable to the energy simulation of the proposed system, a thermoelectric heat pump prototype was built, and its operating data were collected in a fully controlled laboratory environment. By integrating the existing models of each system component used in both dedicated outdoor air systems, detailed energy simulations were performed to compare the energy performance of the proposed dedicated outdoor air system with the reference system. The results showed that the proposed system assisted by the thermoelectric heat pump consumed 23% more operating energy than the reference system because of the lower coefficient of performance of the thermoelectric heat pump compared with the conventional vapor compression system. For comparable energy performance, the proposed dedicated outdoor air system should have heat exchange effectiveness values greater than 49% at least at both the process and secondary air channels of the thermoelectric heat pump, and the figure of merit of the thermoelectric modules used in the thermoelectric heat pump should be over 1.35.

This study aims to estimate the energy performance of a liquid desiccant and evaporative cooling-assisted 100% outdoor air system (LD-IDECOAS) combined with a thermoelectric module integrated proto...

Despite many new advances in supercapacitor material design, few have been adopted for industrial use because of a lack of consideration for industrial requirements. This fact has long been overlooked in academia, but the potential impact of the technical gap between laboratory-scale demonstrations and large-scale applications is considerable. To this end, we performed a proof-of-concept study using vanadium pentoxide (V2O5), one of the most promising supercapacitor electrode materials, to narrow this technical gap. We demonstrated a facile thermal approach in which electrochemically poor bulk V2O5 can be transformed into a highly active electrode material, which can be potentially developed for an economical large-scale production process. Two subsequent thermal treatments of bulk V2O5 under NH3 and H2S gas flow yielded a pseudocapacitive nanocomposite composed of vanadium oxynitride and vanadium sulfide. Superior capacitive performance of the bulk V2O5 in terms of capacitance and stability was achieved by this novel electrode material. In-depth characterization and electrochemical analysis revealed that the underlying reason for this enhancement resulted from a synergistic effect induced by the two-step thermal process. We believe that this successful demonstration of our conceptual approach will be an important stepping stone toward the development of practical material design processes that can meet the rigorous demands of the industry.

The purpose of this study is to investigate the suitable operation and performance of a thermoelectric radiant panel (TERP) in the heating operation. First, the hypothesis was suggested that the heating operation of TERP can operate without a heat source at the cold side according to theoretical considerations. To prove this hypothesis, the thermal behavior of the TERP was investigated during the heating operation using a numerical simulation based on the finite difference method. The results indicated that it is possible to heat the radiant panel using a thermoelectric module without fan operation via the Joule effect. A mockup model of the TERP was constructed, and the numerical model and hypothesis were validated in experiment 1. Moreover, experiment 2 was performed to evaluate the necessity of fan operation in the heating operation of TERP regarding energy consumption. The results revealed that the TERP without fan operation showed the higher coefficient of performance (COP) in the heating season. After determining the suitable heating operation of the TERP, prediction models for the heating capacity and power consumption of the TERP were developed using the response surface methodology. Both models exhibited good R2 values of &gt, 0.94 and were validated within 10% error bounds in experimental cases. These prediction models are expected to be utilized in whole-building simulation programs for estimating the energy consumption of TERPs in the heating mode.

The main objective of this research is to investigate desirable arrangement and spacing of thermoelectric modules (TEMs) to obtain uniform temperature distribution on the surface of a thermoelectric radiant cooling panel (TERCP). A TERCP numerical simulation model was developed based on a two-dimensional heat transfer analysis using the developed TEM model and the finite difference method. The graphical user interface (GUI) was also suggested to provide an easy-to-use design tool for TERCP. Using a developed simulation model, it was found that the triangular configuration of the TEMs on the top surface of the panel with 0.28 m spacing between the TEMs was the most suitable design choice that yields uniform temperature distribution on the bottom surface of the TERCP. To validate the simulation model and proposed panel design, an actual TERCP was constructed and tested under a controlled laboratory environment, and the temperature distribution on the panel surface was measured. The tested TERCP was made of aluminum panel with seven TEMs installed on the top side of the panel with copper substrate, and a heat sink was attached on the hot side of each TEM to release heat to air blowing through the heat sink. The design surface temperature of the proposed panel was 16 °C and the maximum temperature difference between the cold spot and hot spot on the panel surface did not exceed 3 °C as recommended by existing guideline. From the experimental validations, the panel temperature distributions predicted using the TERCP model were in good agreement with the measured panel temperature distributions with a mean error rate below 1.39%. In addition, the parametric study was conducted using validated numerical model to evaluate the effects of design factors and operation conditions on the cooling performance of the TERCP. The results showed that the spacing between TEMs, and outdoor air temperature for heat removal are the main factors to control the cooling performance of the TERCP.

The objective of this study is to investigate the energy saving potential of a dedicated outdoor air system (DOAS) with a thermoelectric module radiant cooling panel (TEM-RCP) by comparing it with those of both a conventional variable air volume (VAV) system and a DOAS with hydraulic ceiling radiant cooling panels (CRCP) via a detailed energy simulation. The theoretical and empirical models for each component were used to estimate the energy performance of a VAV system and a DOAS with CRCP. Additionally, the TEM-RCP was analyzed by using the developed simulation models based on the semi-black box model. Hourly simulations were conducted to measure the annual energy performance. The results indicated that the DOAS with a TEM-RCP consumed 40.7% less operating energy annually when compared with that of the conventional VAV system while the proposed system exhibited only 1.0% more annual energy consumption when compared with the DOAS with hydraulic CRCP given the relatively low dimensionless figure of merit (ZT) of the TEMs (i.e., 0.73) that is used in the TEM-RCP. However, the average coefficient of performance (COP) of the TEM-RCP for cooling was 8.3, which is significantly higher than that of the conventional CRCP (4.6) during the operation period. This is because the TEM-RCP uses a cooling tower for heat removal, and its cooling water temperature is sufficiently low without requiring additional cooling of the TEM except during summer. Therefore, TEM maintains radiant panel temperature with low electric energy consumption. The study also indicated that if the ZT value of TEMs exceeded 0.75, then the proposed system exhibited lower annual energy consumption when compared to that of the DOAS with CRCP.

The main objective of this research was to investigate the impact thermoelectric modules (TEMs) integrated into a liquid desiccant (LD) system have on the heating and cooling of the desiccant solution, and to evaluate the energy saving potential of the proposed system. Two TEM-integrated LD systems were considered; in the first case (i.e., Case A), the TEMs accommodated the solution heating load at the regenerator and a portion of the solution cooling load at the absorber. The remaining solution cooling load was met by an auxiliary chiller. In the second case (i.e., Case B), the TEMs accommodated both the solution cooling and heating loads before the absorber and the regenerator, while extra heat released from the hot side of the TEMs was reclaimed and used to heat the scavenger air entering the regenerator. The conventional LD system, with a boiler and a chiller for heating and cooling the desiccant solution, was also considered as a reference case, to evaluate the energy saving potential of both TEM-integrated LD systems. Hourly energy consumption and temperature variation in the desiccant solution in each system case were predicted via detailed energy simulation with existing mathematical and empirical models for each system component, such as the absorber, regenerator of LD, and TEMs. An approach for determining the required number of TEMs and the optimum temperature difference between the hot side and the cold side of the TEMs is also suggested, based on the coefficient of performance (COP) of the TEMs. It was found that a primary energy saving of about 2% could be expected in Case A compared with the reference case, whereas 55% more primary energy was consumed in Case B. Consequently, based on detailed energy simulations for the TEM-integrated LD system, it was found that the TEMs should be sized to accommodate the regeneration heating load of the desiccant solution before the solution enters the regenerator. In this case, the cooling capacity of the TEMs would be insufficient for cooling the strong solution before the solution enters the absorber, and an auxiliary cooling device would be required.

The objective of this research was to experimentally analyze the cooling performance of a phase-change material-integrated thermoelectric radiant cooling panel (PCM–TERCP) under active and passive cooling operation modes. Empirical models were derived for the PCM–TERCP to provide the available cooling capacity, duration time, and electric power consumption of the panel for the melting period (passive cooling mode) and solidifying period (active cooling mode) under a given operating condition. In the experiments, the durations of both the active and passive cooling were extended by up to 4 h when the thickness of the PCM layer increased from 5 mm to 15 mm. The mean cooling capacities of the proposed panel under the active cooling and passive cooling modes were approximately 58 W/m2 and 54 W/m2, respectively, when the mean radiant temperature (MRT) was 26 °C. Both cooling capacities decreased under lower MRT conditions. Empirical correlations for the cooling duration, cooling capacity, and electric power consumption of the proposed panel were used as objective functions to determine the optimum PCM layer thickness. The optimum PCM thickness of the proposed panel was determined to be 6–8 mm when providing a higher weight to minimizing the electric power consumption than to maximizing the cooling capacity.

A new approach is proposed for investigating the temporal and spatial structures of room impulse responses (IRs) using sound field decomposition. A spherical microphone array was used to analyze the directional characteristics of sound fields through reconstructing the sound fields in an actual chamber hall. To perform directional and spatial characterization of recorded sounds, a plane wave decomposition with an adaptive beamforming technique, such as minimum variance distortionless response (MVDR) spatial spectrum estimation, was employed. Based on the proposed method, a directional impulse response (DIR) was generated in the hall, and the sound level was visualized in a video, which was combined with the viewpoint of each receiver. In addition, the DIR was used to calculate the early energy distribution in three-dimensional directions and the results were represented in the hall plan. This method of acoustic visualization can be used to estimate the effects of architectural design components on the directionality of sounds in rooms.

The objective of this study was to propose and obtain a workable design of a phase change material integrated thermoelectric radiant cooling panel (PCM-TERCP) through numerical and experimental investigations of thermal performance. The proposed PCM-TERCP consists of thermoelectric modules (TEMs), heat sinks, insulation, and PCM layer between two aluminum panels. The PCM layer is a thermal energy storage which provides passive cooling without operation of TERCP by freezing the PCM during the operation period for shifting the electrical load to the off-peak period demand periods. A numerical model of the proposed cooling panel was developed to obtain a desirable configuration of the PCM layer such that it would maintain the surface temperature set-point of the panel during the operation period without the activation of the TEMs of the panel. The numerical model was validated by measurement and data acquired through a laboratory test of the PCM-TERCP mockup. The predicted results agreed well with the measurement data, within the 10% error bounds. A parametric study was carried out to determine the critical design parameters affecting the cooling performance of PCM-TERCP. The results indicated that the panel surface temperature was significantly affected by the number of heat fins inside the PCM and thickness of the PCM layer. A 10-mm-thick PCM layer with more than five heat fins per unit length of the panel was the most feasible solution among the several cases considered in this study for PCM-TERCP to satisfy the design requirements for application in a conditioned space. In addition, it was revealed that the liquid fraction of PCM should be under 0.6–0.65 for efficiently using the latent heat of PCM by enhancing the heat transfer of PCM.

Cellulose microfibril is a major cell wall polymer that plays an important role in the growth and development of plants. The gene cellulose synthase A (CesA), encoding cellulose synthases, is involved in the synthesis of cellulose microfibrils. However, the regulatory mechanism of CesA gene expression is not well understood, especially during the early developmental stages. To identify factor(s) that regulate the expression of CesA genes and ultimately control seedling growth and development. The presence of cis-elements in the promoter region of the eight CesA genes identified in flax (Linum usitatissimum L. ‘Nike’) seedlings was verified, and three kinds of ethylene-responsive cis-elements were identified in the promoters. Therefore, the effect of ethylene on the expression of four selected CesA genes classified into Clades 1 and 6 after treatment with 10−4 and 10−3 M 1-aminocyclopropane-1-carboxylic acid (ACC) was examined in the hypocotyl of 4–6-day-old flax seedlings. ACC-induced ethylene either up- or down-regulated the expression of the CesA genes depending on the clade to which these genes belonged, age of seedlings, part of the hypocotyl, and concentration of ACC. Ethylene might be one of the factors regulating the expression of CesA genes in flax seedlings.

This study aims to estimate the performance of thermoelectric module (TEM) heat pump for simultaneous liquid cooling and heating and propose empirical models for predicting the heat exchange effectiveness. The experiments were conducted to investigate and collect the performance data of TEM heat pump where the working fluid was water. A total of 57 sets of experimental data were statistically analyzed to estimate the effects of each independent variable on the heat exchange effectiveness using analysis of variance (ANOVA). To develop the empirical model, the six design parameters were measured: the number of transfer units (NTU) of the heat exchangers (i.e., water blocks), the inlet water temperatures and temperatures of water blocks at the cold and hot sides of the TEM. As a result, two polynomial equations predicting heat exchange effectiveness at the cold and hot sides of the TEM heat pump were derived as a function of the six selected design parameters. Also, the proposed models and theoretical model of conventional condenser and evaporator for heat exchange effectiveness were compared with the additional measurement data to validate the reliability of the proposed models. Consequently, two conclusions have been made: (1) the possibility of using the TEM heat pump for simultaneous cooling and heating was examined with the maximum temperature difference of 30 °C between cold and hot side of TEM, and (2) it is revealed that TEM heat pump has difference with the conventional evaporator and condenser from the comparison results between the proposed models and theoretical model due to the heat conduction and Joule effect in TEM.

The relationship between the objective characteristics of the stage performance environment and the subjective impressions of musicians was investigated in two chamber halls with different architectural characteristics. In order to characterize the stage, acoustical and visual parameters were measured and representative parameters were derived using principle components analysis. Stage support (ST) parameters, such as STEarly and STLate, were selected as main factors and measured at various measurement positions on the stage according to ISO 3382-1. Subjective evaluations were also conducted to find the musicians' subjective impressions of acoustic conditions, including overall quality in solo, duet, and quartet performances during in-situ performances at six positions on the stage. Subjective evaluations indicate that the stage front is the most preferred position for musicians and the differences in response to the positions were less significant for a solo performance compared to those for duet and quartet performances. The relationship between ST parameters and subjective impressions was investigated using correlation and multiple regression analyses. From the results, it was found that the soloists' preferences increased but the quartet performers' preferences decreased under conditions with stronger early and late reflections.

Performance simulations of thermoelectric radiant panels (TERPs) provide valuable information for the use of TERPs as alternatives to conventional hydraulic radiant panels, which require refrigerants based on the vapor compression cycle. Several existing models are appropriate for the design of the TERP; however, there are limitations to the building simulation with respect to the evaluation of the annual energy performance because existing models for TERP are based on the numerical method, therefore it is very complex to integrate with the building model. To overcome these limitations, simplified empirical models should be developed based on experimental data and then verified. This study aims to develop two simplified prediction models for the cooling capacity and energy consumption of TERPs. Using the 2k factorial experiment design method, a total of 16 experiment sets were designed according to the four main operation parameters: room temperature, outdoor air temperature, face velocity of air in duct, and combined heat transfer coefficient between room and panel surface. The developed models were designed in dimensionless forms to ensure broad applicability. The developed models yielded good R2 values exceeding 0.99 and were validated under additional operation conditions. Finally, the guidance of using the developed models and the performance tables of the TERPs was confirmed with respect to the use of TERPs in the construction of heating, ventilation, and air conditioning (HVAC) systems.

A phase change material based radiant cooling panel with thermoelectric module (PCM-TERCP) is proposed in this study. It consists of two aluminium panels, and phase change materials (PCMs) sandwiched between the two panels. Thermoelectric modules (TEMs) are attached to one of the aluminium panels, and heat sinks are attached to the top side of TEMs. PCM-TERCP is a thermal energy storage concept equipment, in which TEMs freeze the PCM during the night whose melting temperature is 16○C. Therefore, the radiant cooling panel can maintain a surface temperature of 16◦C without the operation of TEM during the day. Furthermore, it is necessary to design the PCM-TERCP in a way that it can maintain the panel surface temperature during the targeted operating time. Therefore, the numerical model was developed using finite difference method to evaluate the thermal behaviour of PCM-TERCP. Experiments were also conducted to validate the performance of the developed model. Using the developed model, the possible operation time was investigated to determine the overall heat transfer coefficient required between radiant cooling panel and TEM. Consequently, the results showed that a overall heat transfer coefficient of 394 W/m2K is required to maintain the surface temperature between 16○C to 18○C for a 3 hours operation.

The purpose of this research is to evaluate the performance of a novel model that incorporates a thermoelectric generator (TEG) and phase change material (PCM). The proposed model passively generates electricity using waste heat that accumulates at exterior wall surfaces. The main generator is a TEG. To maintain the temperature difference between the two sides of the TEG, PCM is located at its cold side—thus converging the heat transferred into latent heat. The proposed passive generation system is formed into a TEG-PCM block. The block can be stacked to form a wall or inserted into any part of a building that faces the sun. The experiment setup is based on a constant temperature method. The wall temperature profile is set according to solar radiation, convection, and radiative heat transfer. To replicate daily wall temperatures during the experiment, a heat plate is used to match a wall temperature profile. Step control was used for the heating plate. The resulting data shows the average temperature difference between the hot and cold sides of the TEG to be 10-20°C. The peak generated electricity was 0.08 W for a single module.

The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high-speed train cabin geometry. The speech transmission index (STI) and privacy distance (rP) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high-, medium- and low-absorption coefficient cases. Interior materials with high absorption coefficients yielded a low rP, and the ceiling had the largest impact on both the STI and rP among the interior elements. Combinations of the three cases were measured, and the maximum reduction in rP by the absorptive surfaces was 2.4 m, which exceeds the space between two rows of chairs in the high-speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for rP using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in rP in the acoustic design of interior materials to improve speech privacy in train cabins.

The effects of diffusing elements on sound field diffuseness were investigated by subjective evaluations using binaural impulse responses (BIRs) in seating areas in a surround hall. The room acoustical parameters as well as the number of peaks (Np) and local maxima within -20 dB of the amplitude of direct sound were investigated to evaluate the diffuseness in the halls. For the listening test, stimuli were selected to explore the combination of acoustic parameters and degree of diffusion. The music signals were convolved with the measured BIRs in different listening positions. Based on the listening test, it was found that positions close to the diffusers with a high scattering coefficient were preferred by the listeners.

In multi-story buildings, sound reduction can be evaluated using sound prediction model defined in the EN 12354 in Europe generally. The reduction model deals with the calculation and evaluation of direct and flanking transmission between two rooms through each structure elements for example the floor, ceiling, inner wall, or etc. In case of Korea, general residential type of is multi-story building so the noise transmission between neighbors is the most well-known acoustical problem. The EN 12354 can be considered as an important evaluation method, however the acoustic environment in Korea should be considered for the applicability of prediction model. Therefore, acoustical environments of multi-story buildings were investigated using field survey in order to evaluate the applicability through EN 12354.

A wall diffuser has been designed for high scattering and diffusion coefficients using tenth-scale models. The diffuser profiles of the diffuser were designed based on using the Voronoi diagrams to create a randomized pattern with a plane surface with a particular structural height. The intaglio and embossed patterns of these profiles were compared by measuring the scattering and the diffusion coefficients. The intaglio diffusers showed higher scattering and diffusion coefficients than the embossed diffusers. Moreover, random arrays of the profiles presented resulted in higher scattering and diffusion coefficients than the sequential arrays ordered sequentially in terms of the profile in the structural height. The effects of diffusers on sound-field diffuseness were also investigated, and it was found that the diffusive surfaces tend to produce more diffused early reflections than the fine reflective surfaces.

A monitoring and alarming system was designed to detect household noise occurrence in the multi-story residential buildings. This system is composed of a microphone combined with a home smart pad installed on a wall and a main server that can store data to discriminate household noise occurrence. Sound levels such as LAeq and LAmax were calculated in real time using developed digital signal processor (DSP) of the acoustical parameter analyzer in the home smart pad. A correction equation was applied based on the standard measurement method to provide accurate measurements. After measurement, the results were saved in the main server using Ethernet and inter-compared with the data of each household to discriminate the household noise occurrence. Finally, the alarm was raised depending on the decision criteria based on both the regulations of Korean government and subjective evaluation results from the previous study.

A teleconference system was developed to transmit speech signals for audio communication with remote users. The hardware system was composed of 3-D microphone arrays to capture directional sound and a wireless headset to provide freedom of movement for users. An application programming interface (API) was used for interaction between the computer and the audio devices, including the microphone, headphone, and ADDA converter, transferring input/output audio signals in real time through the network. For the evaluation of the system, a latency test was performed with a simultaneous recording system in capturing and reproduction positions. The latency from the network procedure was calculated with different buffer sizes, and the lower-delay and smaller-deviation buffer was selected. In addition, the transmitted audio signals were compared with the input signals in terms of signal patterns and frequency responses. The resulting audio qualities in the time and frequency domain were suitable for a teleconferencing system.

The room acoustical characteristics have been investigated in temporal and spatial structures of room impulse responses (IRs) at different audience positions in real halls. The spherical microphone array of 32-channel is used for measurements process. Specular and diffusive reflections in IRs have been visualized in temporal domain with sound-field decomposition analysis. For plane wave decomposition, the spherical harmonics are used. The beamforming technique is also employed to make directional measurements and for the spatio-temporal characterization of sound field. The directional measurements by beamforming are performed for producing impulse responses for the different directions to characterize the sound. From the estimation of spatial characterization, the reflective surfaces of the hall are indicated as responsible for specular and diffusive reflections.

In this study, a 1:10 scale model was used to evaluate the acoustical parameters and speech transmission indices in high-speed train cabins when the interior design factors are changed to improve speech privacy. The 1:10 scale model materials were selected by considering real measured target factors, such as reverberation time (RT) and speech level (Lp,A,s). The characteristics of the background noise in a high-speed train depend on the train’s speed; therefore, recordings of the background noise (LAeq) inside a train were considered in three situations: a stopped train, a train traveling at 100 km/h, and a train traveling at 300 km/h. The values of the STI were reproduced with the background noise levels at each speed using external array speakers with an equalizing filter in the scale model. The shapes and absorptions of chairs and interior surfaces were evaluated using scale modeling.