KANSEI evaluation of color images presented in color gamuts with different blue primaries

The effect of blue primary color on image quality was studied. We used the KANSEI evaluation method, and for experiments, we used Semantic Differential method. First, four different blue primaries of 430, 450, 470, and 480 nm with full brightness of L_max equal 60 cd/m² were tested. The same experiment was performed for 450, 470, and 480 nm at L_max of 170 cd/m². The results for the four primaries show that 450‐ and 470‐nm blue primaries are the best. Then 430 nm was next, and 480‐nm blue primary shows the worst performance. In the tests of three primaries, the 470 nm shows the highest scores for bluish test images. Results are compared with color naming data in the entire chromaticity diagram.     

The feedback of heat rejection to air conditioning load during the nighttime in subtropical climate

Taipei City, located in the subtropical zone, has a basin landform. The summer is always hot and humid and the air temperature right after sunset is typically higher than 30 °C. Heat rejection from residential buildings in urban area, equipped with lots of the window type air conditioners, not only increases the air temperature outside, but also burdens the cooling load. Based on the time schedule of air conditioner use of Taipei citizens, the heat rejection/building energy use and the air temperature distribution were evaluated, and finally the additional electric consumption of air conditioners was predicted. Two software, EnergyPlus (building energy program) and Windperfect (CFD, computational fluid dynamics software) were employed in this study. In the CFD simulation, the geometry of buildings that covers 700 m in diameter was created with GIS (geographical information system) and the total mesh number was more than 3 millions. Three specified temperatures (T_am, T_bu and T_ac) were used to describe the temperature distribution within the urban canopy by hourly time variation and spatial distribution with height and horizontal profile. The results revealed that the temperature gradually increased with height and the temperature next to the buildings was always higher than the ambient air. The feedback (penalty) of heat rejection to cooling load was found 10.7% during 19:01 to 02:00 h on the following day.     

Estimation of heat rejection based on the air conditioner use time and its mitigation from buildings in Taipei City

The main work in the research focuses on the analysis and mitigation of the anthropogenic heat discharged from buildings, which is one of the main reasons leading to the heat island effect. The residential and commercial buildings, divided into 10 categories, with HVAC systems were analyzed by the building energy program, EnergyPlus. With the help of GIS, the heat rejection of all the residential and commercial buildings in DaAn Ward of Taipei City were evaluated, in which the spatial data and diurnal variation of the heat rejection were described by 3-h time periods. Furthermore, the effect of mitigation strategies was discussed. The first strategy was to change the wall/roof material of building envelope. The second and third strategies, from the viewpoint of energy saving, were to change the temperature setting of air conditioners and to turn off the lighting and equipment when not in use. The fourth strategy was to use a better efficiency of the cooling systems. Finally, the evaluation of installing the water-cooled cooling system, which discharges heat in the form of sensible and latent heat, was also included.     

Nitrogen desorption from pure iron melts under reduced pressure

More recently, lower nitrogen contents of steel are required in view of its workability and applicability. The present study covers basic investigations on the improvement of mass transfer in denitrogenation of steel melts under vacuum. Extensive reduction of the contents of the surface-active elements oxygen and sulfur is a precondition to increase the rate of nitrogen desorption. Kinetics of nitrogen transfer is reliably described by a mixed control model which includes diffusion in the melt, interfacial reaction and diffusion in the gas phase. Particularly at low oxygen and sulfur contents, mass transfer of nitrogen during desorption from steel melts is markedly accelerated. A convincing explanation of this phenomenon has not been found yet.     

FT-IR studies of decarbonylation and recarbonylation of [Pt3(CO)6] 5 2− supported on dehydrated SiO2

Decarbonylation of [Pt₃(CO)₆]₅ on SiO₂ at 373 K produced [Pt₃(t-CO)₃]₅ species, where all the terminal CO remained. Complete decarbonylation at 423 K was not observed, which led to aggregation at 473 K. The interaction of some Pt with SiO₂ inhibited complete recarbonylation to [Pt₃(CO)₆]₅.     

Segmentation of abnormal liver region based on earth mover’s distance between histograms with mapping of the distances by multidimensional scaling

In this paper, we propose using earth mover’s distance (EMD) to obtain the appropriate similarity between each histogram for segmentation of abnormal liver regions with mapping of the distances by multidimensional scaling. Conventionally, the similarity between each histogram is calculated by integrating the difference between each bin of the histograms. However, this similarity is unsuitable for appropriate comparison of the histograms because the number of bins for calculating the local histograms of computed tomography images varies. We used EMD to resolve this problem regarding the difference in bin numbers, and the obtained distances are used for mapping the local histograms by multidimensional scaling to low-dimensional space. In the low-dimensional space, the abnormal liver region was well segmented by support vector machine in the test datasets.     

Low-Temperature Structural Phase Transition in ZrO2–12 mol% CeO2 Studied by Infrared Spectroscopy and X-ray Diffractometry

The low-temperature tetragonal ( t ) to monoclinic ( m ) phase transition in ZrO₂–12 mol% CeO₂ was studied by Fourier-transform infrared spectroscopy and X-ray diffractometry (XRD). When the ZrO₂–12 mol% CeO₂ was cooled, the t → m phase transition occurred at about 120 K; this caused significant changes in the infrared reflectance spectra and X-ray diffractograms. As the phase transition proceeded, "difference spectra" obtained by subtracting the infrared spectra before and after the phase transition revealed two infrared modes at 575 and 740 cm⁻¹ which were assigned to the m phase. The volume fraction of the m phase (determined by XRD) and the subtraction coefficient (defined such that the difference spectra reproduced the infrared spectrum of m -ZrO₂) were consistent with each other; this revealed a marked discontinuity at about 120 K. Full width at half maximum of the ( 1 11) _m and (111) _t reflections also indicated a similar discontinuity at about 120 K.     

Origins of peaks of graphitic and pyrrolic nitrogen in N1s X-ray photoelectron spectra of carbon materials: quaternary nitrogen,tertiary amine,or secondary amine?

X-ray photoelectron spectroscopy (XPS) is among the most powerful techniques to analyse structures of nitrogen-doped carbon materials. However, reported assignments of (1) graphitic nitrogen (N)/substitutional N, quaternary N (Q–N), or tertiary amine (T–N) and (2) pyrrolic N/secondary amine or T–N are questionable. Most reports assign peaks at ca. 401 eV as Q–N or graphitic N, whereas raw materials in most of those works contain neither counter anion nor halogen. Besides, the peak at ca. 400 eV has been assigned as pyrrolic N, but the presence of N–H is generally not confirmed. In this work, it was clarified that one of the reasons for the prevailing ambiguous assignments is the presence of N in heptagonal and pentagonal rings. The peaks at 400.1–401.2 eV were determined to be T–N, but not Q–N by analyzing graphitized polyimide (with the oxygen content of 0.01 at% or lower and the hydrogen content of 0 at%) using Raman spectroscopy, XPS, X-ray diffraction, total neutron scattering, elemental analysis, and molecular dynamics simulation. Besides, it was revealed that the peak at 400.1 eV originated from T–N on 5-membered rings or 7- and 5-membered rings, but not pyrrolic N because graphite including no hydrogen was used for analysis.

Graphical abstract

     

Identification of system characteristics of a power system with time series data. Identification of frequency fluctuation characteristics of a small‐scale isolated system

Understanding actual characteristics of a power system with recorded time series data is of great importance, for example, in improving the performance of the system. Although system identification is a well‐known technique to achieve this goal, its applicability to a certain system should be examined for the particular case because its accuracy highly depends on the inherent characteristics of the system. While many papers have discussed application of a system identification technique to a power system, few papers have examined its applicability to the actual data of a power system. This paper presents a new system identification method to estimate characteristics of a power system while using output of intermittent generators or fluctuating loads as an external disturbance. The method employs cross spectra and coherence as a key factor in the identification; it estimates a transfer function of a power system, contribution of observed disturbance to total disturbance, and so on. The method is applied to time series data of two model systems: simulation results and measured data of an isolated power system with diesel generators. The study gives satisfactory results; implication on the accuracy of the method is discussed through the sample studies. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(3): 36–45, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20051