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This paper presents a design strategy of an induction motor (IM) for a wide constant power speed range (CPSR). The stator inductance is a key parameter that determines a CPSR, because it affects the voltage limit and the torque simultaneously. Low inductance allows a wide CPSR under a voltage limit. However, it results in torque reduction. On the other hand, if inductance is high, the opposite results take place; high torque and narrow CPSR. Therefore, there is a tradeoff between the power level and the speed range. The classical design process does not consider the CPSR, but provides a guideline to calculate core dimensions and the winding number for a nominal operation point. Thereby, the machine inductance is determined passively. This classical procedure is not appropriate for widening the CPSR. To extend the speed range under a voltage limit, a proper inductance must be chosen in the first place. In this work, a different IM design process is pursued with the objective of widening CPSR: An optimal inductance is obtained that minimizes the maximum current under a constant power condition. In the secondary part, an IM design method is proposed, which determines the winding number and the core dimension under a given inductance. Finally, the proposed analytic design is compared with the design optimized by finite-element-analysis. Based on the design results, a real IM (130 kW, 14 000 r/min) is constructed and tested. The experimental results are in good agreement with the design data. [ABSTRACT FROM AUTHOR]

A copper-loss-minimizing torque control method is considered for wound synchronous machines (WSMs) in the field-weakening region. In general, the current-minimizing solutions are often found at the intersection of the torque and voltage curves. However, those curves change depending on the rotor field current in WSM. This complicates the problem of obtaining an analytic loss-minimizing solution. In this study, a hybrid approach is suggested: analytic method, iterative computation, and curve fitting. The Ferrari's method is repeatedly applied for each field current to find intersections between the voltage limit and torque curves. Then, a loss-minimizing current set is found at the minimum of a second-order function fitted to three Ferrari's solutions. At each step, inductance changes are reflected. In the cost function, the field-winding copper loss is included along with the stator copper loss. The results show that the total loss is minimized at a point where the power factor is slightly lower than unity. Simulations and experiments were carried out for a 60-kW WSM to show the usefulness of the algorithm. [ABSTRACT FROM PUBLISHER]

A new set of Infrared Atmospheric Sounding Interferometer (IASI) channels was re-selected from 314 EUMETSAT channels. In selecting channels, we calculated the impact of the individually added channel on the improvement in the analysis outputs from a one-dimensional variational analysis (1D-Var) for the Unified Model (UM) data assimilation system at the Met Office, using the channel score index (CSI) as a figure of merit. Then, 200 channels were selected in order by counting each individual channel's CSI contribution. Compared with the operationally used 183 channels for the UM at the Met Office, the new set shares 149 channels, while the other 51 channels are new. Also examined is the selection from the entropy reduction method with the same 1D-Var approach. Results suggest that channel selection can be made in a more objective fashion using the proposed CSI method. This is because the most important channels can be selected across the whole IASI observation spectrum. In the experimental trial runs using the UM global assimilation system, the new channels had an overall neutral impact in terms of improvement in forecasts, as compared with results from the operational channels. However, upper-tropospheric moist biases shown in the control run with operational channels were significantly reduced in the experimental trial with the newly selected channels. The reduction of moist biases was mainly due to the additional water vapor channels, which are sensitive to the upper-tropospheric water vapor. [ABSTRACT FROM AUTHOR]

An overmodulation method is proposed for an in-wheel system where two motors are coupled to a sum gear. In the dual-motor dual-inverter single shaft systems, the output voltage magnitudes of two inverters are not the same in the overmodulation range due to the angle offset between two motors. In this article, to maintain torque balance in the overmodulation region, holding vectors are defined between adjacent vertices of two voltage hexagons. Around these vectors, the holding region is also defined by the holding angle. If a reference voltage vector is in the holding region, it is modulated to the holding vector; otherwise, it is modulated to the vector on the arc of inscribed circle. For a given the modulation index (MI), the holding angle is obtained based on the Fourier series expansion. The proposed method keeps the output voltages of two inverters the same even if two motors have the angle offset. Further, it has the characteristic of maintaining the linearity between the reference and output MI to the maximum MI. The proposed overmodulation method is demonstrated by simulation and experimental results. [ABSTRACT FROM AUTHOR]

Recently, various waste microplastics sensors have been introduced in response to environmental and biological hazards posed by waste microplastics. In particular, the detrimental effects of nano-sized plastics or nanoplastics have been reported to be severe. Moreover, there have been many difficulties for sensing microplastics due to the limited methodologies for selectively recognizing nanoplastics. In this study, a customized gold nanoparticles (Au NPs) based localized surface plasmon resonance (LSPR) system having bio-mimicked peptide probes toward the nanoplastics was demonstrated. The specific determination through the oligo-peptide recognition was accomplished by chemical conjugation both on the LSPR chip's 40~50 nm Au NPs and sandwiched 5 nm Au NPs, respectively. The peptide probe could selectively bind to polystyrene (PS) nanoplastics in the forms of fragmented debris by cryo-grinding. A simple UV-Vis spectrophotometer was used to identify the LSPR sensing by primarily measuring the absorbance change and shift of absorption peak. The sandwich-binding could increase the LSPR detection sensitivity up to 60% due to consecutive plasmonic effects. In addition, microwave-boiled DI water inside of a styrofoam container was tested for putative PS nanoplastics resource as a real accessible sample. The LSPR system could be a novel protocol overcoming the limitations from conventional nanoplastic detection. [ABSTRACT FROM AUTHOR]

As a contribution to phase 6 of the Coupled Model Intercomparison Project (CMIP6), the global climate simulated by an atmospheric general circulation model (GCM), the Seoul National University Atmosphere Model version 0 with a Unified Convection Scheme (SAM0-UNICON), is compared with observation and climates simulated by the Community Atmosphere Model version 5 (CAM5) and Community Earth System Model version 1 (CESM1), on which SAM0-UNICON is based. Both SAM0-UNICON and CESM1 successfully reproduce observed global warming after 1970. The global mean climate simulated by SAM0-UNICON is roughly similar to that of CAM5/CESM1. However, SAM0-UNICON improves the simulations of the double intertropical convergence zone, shortwave cloud forcing, near-surface air temperature, aerosol optical depth, sea ice fraction, and sea surface temperature (SST), but is slightly poorer for the simulation of tropical relative humidity, Pacific surface wind stress, and ocean rainfall. Two important biases in the simulated mean climate in both models are a set of horseshoe-shaped biases of SST, sea level pressure, precipitation, and cloud radiative forcings in the central equatorial Pacific and a higher sea ice fraction in the Arctic periphery and Southern Hemispheric circumpolar regions. Both SAM0-UNICON and CESM1 simulate the observed El Niño–Southern Oscillation (ENSO) reasonably well. However, compared with CAM5/CESM1, SAM0-UNICON performs better in simulating the Madden–Julian oscillation (MJO), diurnal cycle of precipitation, and tropical cyclones. The aerosol indirect effect (AIE) simulated by SAM0-UNICON is similar to that from CAM5 but the magnitudes of the individual shortwave and longwave AIEs are substantially reduced. [ABSTRACT FROM AUTHOR]

A systematic warm bias in the tropical tropopause layer (TTL) is commonly found in both climate and numerical weather prediction models. In this study, the nature of this temperature bias is examined by integrating the MetOffice Unified Model (MetUM) with various ozone concentrations in the TTL. Like other models, the long‐term integration of MetUM with the Atmospheric Model Intercomparison Project (AMIP) configuration shows a notable warm bias (∼2 K) in the TTL with a comparable cold bias in the tropical stratosphere above ∼70 hPa. We demonstrate that these biases are particularly sensitive to the tropical ozone concentration prescribed in the model. By replacing the background ozone, which is typically used for AMIP‐type simulations, with the Southern Hemisphere ADditional OZonesondes (SHADOZ) measurements or the Binary Data Base of Profiles (BDBP), the dipolar temperature biases in the TTL and tropical stratosphere are significantly reduced. Further sensitivity tests show that the tropical ozone amount in a 14–20 km layer is a key contributor to this change. These results suggest that accurate ozone forcing in the TTL is crucial for reliable weather and climate simulations. Latitude–pressure distributions of zonal‐mean temperature bias for the 20‐year (1989–2008) AMIP simulations: (a) CTR, (b) SOZ, (c) BDBP, (d) SOZ_TTL and (e) BDBP_TTL. The biases are computed from ERAI temperatures for the same period. Shading and contour intervals are 0.2 and 0.5 K, respectively. [ABSTRACT FROM AUTHOR]

Purpose IBM Watson for Oncology (WFO) is a clinical decision-support computing system that provides oncologists with evidence-based treatment recommendations for a variety of cancer diagnoses. The evidence-based supported treatment recommendations are presented in three categories: Recommended, representing the Memorial Sloan Kettering Cancer Center (MSKCC) preferred approach; For Consideration, evidence-based alternative treatments; and Not Recommended, alternative therapies that may be unacceptable. We examined the absolute concordance of treatment options with that of the recommendations of a multidisciplinary team of oncologists from Gachon University, Gil Medical Centre, Incheon, South Korea. Methods We enrolled 656 patients with stage II, III, and IV colon cancer between 2009 and 2016. Cases were processed using WFO and, using retrospective clinical data, outputs were compared with the actual treatment the patient received. Absolute concordance was defined as an alignment of recommendation in the Recommended MSKCC preferred-approach category. Treatment recommendations that were represented in the For Consideration category were not the focus of this study. Results The absolute concordance between the WFO-derived MSKCC preferred approach and Gil Medical Centre treatment recommendations was 48.9%. The percentage of cases found to be acceptable was 65.8% (432 of 656) and the stage-specific concordance rate was 32.5% for patients with stage II disease who had risk factors and 58.8% for patients with stage III disease. Patients 70 years of age and older had a concordance rate of only 20.2%, whereas younger patients had a concordance rate of 63.8% (P = .0001). Conclusion The main reasons attributed to the low concordance rate were age, reimbursement plan, omitting chemotherapy after liver resection, and not recommending biologic agents (ie, cetuximab and bevacizumab). [ABSTRACT FROM AUTHOR]

Agastache rugosa (Fisch. & C.A.Mey.) Kuntze has been widely used as a food spice and a remedy for colds in Korea, China and Japan. In this study, one new flavone glycoside ( 1 ) along with six flavonoids ( 2 – 7 ), nine phenyl glycosides ( 8 – 16 ) and three megastigmane glycosides ( 17 – 19 ) were isolated from the leaves of A. rugosa. By extensive spectroscopic methods including 1D and 2D NMR, and MS data, the structure of the new compound ( 1 ) was elucidated as acacetin 7- O -β-(6″-( E )-crotonylglucopyranoside). From present investigation, compound 1 and 7 – 19 were isolated for the first time from the genus Agastache and 1 , 16 , 18 and 19 in the Lamiaceae family. [ABSTRACT FROM AUTHOR]

Electrically excited synchronous motors are designed to have high power density for electric vehicle applications. During a high-torque operation, severe nonlinearities associated with a saturation are observed: change of inductances, emergence of cross-coupling effects, variation of back EMF coefficient, etc. A flux linkage map over the current plane is obtained via finite-element analysis (FEA), and it is fitted by a third-order polynomial with the use of the least square method. Then, by grouping terms of the polynomial, the inductances are expressed as functions of currents. The validity of inductance fitting is shown by comparing with FEA and experimental results. This enables us to predict inductances online instead of using premade lookup table. The torque equation is expanded by incorporating the cross-coupling inductances, for which an extended maximum torque per ampere (MTPA) is developed by using Ferrari's method to a quartic equation. The extended MTPA locus is compared with the experimental optimal results. [ABSTRACT FROM PUBLISHER]

This study investigates the effects of atmosphere-ocean coupling for medium-range forecasts by using coupled numerical weather prediction (NWP) experiments based on the unified model (UM) on a case study of the 2016 heatwave over the Korean Peninsula. Atmospheric nudging experiments were carried out to determine the key regions which may have large impacts on the forecasts of the heat wave. The results of the nudging experiments suggest that key forcing from the Mongolia region gives the largest impact to this case by causing a transport of warm air from the northwest part of Korea. Moreover, the Pacific region shows an important role in the global circulation in nudging experiments. Results from the atmosphere-ocean coupled model show no clear benefit for the extreme heat wave temperatures in this case. In addition, more model development seems to be needed to improve the representation of sea surface temperature (SST) in some key areas. Nevertheless, it is confirmed that the atmosphere-ocean coupled simulation produces a better representation of aspects of the large-scale flow such as the blocking high over the Kamchatka Peninsula, the high pressure system in the northwest Pacific and Hadley circulation. The results presented in this study show that atmosphere-ocean coupling can be an important way to improve the deterministic model forecasts as the lead time increases beyond a few days. [ABSTRACT FROM AUTHOR]

An accurate radiative transfer model (RTM) is essential for the retrieval of soil moisture (SM) from microwave remote sensing data, such as the passive microwave measurements from the Soil Moisture Active Passive (SMAP) mission. This mission delivers soil moisture products based upon L-band brightness temperature data, via retrieval algorithms for surface and root-zone soil moisture, the latter is retrieved using data assimilation and model support. We found that the RTM based on the tau-omega (τ-ω) model can suffer from significant errors over croplands in the simulation of brightness temperature (Tb) (in average between −9.4K and +12.0K for single channel algorithm (SCA); −8K and +9.7K for dual-channel algorithm (DCA)) if the vegetation scattering albedo (omega) is set constant and temporal variations are not considered. In order to reduce this uncertainty, we propose a time-varying parameterization of omega for the widely established zeroth order radiative transfer τ-ω model. The main assumption is that omega can be expressed by a functional relationship between vegetation optical depth (tau) and the Green Vegetation Fraction (GVF). Assuming allometry in the tau-omega relationship, a power-law function was established and it is supported by correlating measurements of tau and GVF. With this relationship, both tau and omega increase during the development of vegetation. The application of the proposed time-varying vegetation scattering albedo results in a consistent improvement for the unbiased root mean square error of 16% for SCA and 15% for DCA. The reduction for positive and negative biases was 45% and 5% for SCA and 26% and 12% for DCA, respectively. This indicates that vegetation dynamics within croplands are better represented by a time-varying single scattering albedo. Based on these results, we anticipate that the time-varying omega within the tau-omega model will help to mitigate potential estimation errors in the current SMAP soil moisture products (SCA and DCA). Furthermore, the improved tau-omega model might serve as a more accurate observation operator for SMAP data assimilation in weather and climate prediction model. [ABSTRACT FROM AUTHOR]

In this study, high electron mobility transistor (HEMT) device was used as an immuno biosensor to measure concentration of a stress hormone, cortisol, by using selective binding on cortisol monoclonal antibody (c-Mab). Also, the HEMT sensor was enhanced in its sensitivity through light illumination to generate photocurrent. The optical pumping could assist the biosensor to discriminate more detailed change, which could result in an increment of limit of detection (LOD) to 1.0 pM cortisol level. It was the lowest level of detection with semiconductor device-based cortisol biosensors and the enhancement of surface potential sensitivity was induced by laser light (532 nm). Output current amplificated by photocurrent was higher than dark original current at about 3.39% when gate voltage is applied with −3 V. Since the device could be applied to not only standard cortisol solution but also real human salivary sample, it is expected to apply for in vitro direct diagnosis of point-of-care test (POCT). • High electron mobility transistor (HEMT) sensor was demonstrated for a direct cortisol measurement using c-Mab immune-detection. • The HEMT sensor could measure 1.0 pM levels of cortisol standard solution and in human salivary sample. • Detection efficiency of cortisol was enhanced by optical pumping of AlGaN/GaN layer through laser illumination. [ABSTRACT FROM AUTHOR]