Tolerance Sensitivity Analysis and Robust Optimal Design Method of a Surface-Mounted Permanent Magnet Motor by Using a Hybrid Response Surface Method Considering Manufacturing Tolerances

This paper presents a robust optimal design method using a hybrid response surface method (H-RSM) which directly finds an optimal point satisfying a target Z-value or a probability of failure. Through three steps, this paper achieves the goal that is to increase the open-circuit airgap flux (OCAF) in a surface-mounted permanent magnet motor and decrease its variation caused by variations of the airgap lengths including an additional one between permanent magnets and rotor back yoke. First, the OCAF equation is derived from the magnetic equivalent circuit (MEC) considering the additional airgap. Then, the equation is validated by comparing its results with those of the finite element method (FEM) modeled by the slotless stator. Next, the tolerance sensitivity analysis, using the partial derivative of the OCAF equation with respect to the airgap length, is performed to investigate the effects of design variables on the OCAF. It is shown that increasing the magnet thickness is effective for both increasing mean of the OCAF and reducing its variation. Finally, robust optimal design is performed using the H-RSM, in which all data are obtained from the FEM modeled by the slotted stator. The results of the robust optimal design are verified using the FEM

How Do Institutional Investors Interact With Sell-Side Analysts?

This paper examines how institutional investors interact with sell-side analysts (hereafter, SSAs) in Korean stock market. In particular, we examine the role of institutional investors as a more sophisticated mechanism which incorporates sell-side analysts’ stock recommendation, target price, and earnings forecast more rapidly than individual investors do. Moreover, we examine whether institutional investors differentiate the quality of sell-side analysts’ information. By using a sample of 1,421 firm-year observations in Korean stock market during 2001–2011, we find that the change of institutional investor’s ownership has a significantly positive association with the level of equity value estimates based on SSAs’ earnings forecasts relative to stock prices and their stock recommendation which are considered as SSAs’ indicator of stock market’s mispricing. In addition, we find that only when SSAs provide more accurate earnings forecasts, institutional investors incorporate SSA’s information into their stock trading. Thus, we conclude that institutional investors in Korean stock market contribute to the enhancement of stock market efficiency by incorporating SSAs’ information into their stock trading more rapidly than individual investors. Our findings add to the literature by shedding a light on the unobserved interaction among more sophisticated stock market participants, such as institutional investors and sell-side analysts

Effect of Ginseng Powder Supplementation on the Physicochemical Properties, Antioxidant Capacity, and Sensory Characteristics of Cream Soup

Ginseng has been used as a medicinal herb in Asian countries for hundreds of years. It contains many kinds of ginsenosides as major active ingredients and is known to have neuroprotective, anti-inflammatory, antitumor, and antidiabetic properties. In this study, we have developed cream soup with different concentrations (0%, 3%, 5%, 7%, and 10%) of ginseng powder (GP) and determined the quality characteristics (color, viscosity, salinity, etc.) and antioxidant activity, along with sensory parameters. After the addition of GP, significant differences in salinity, L* and a*color value, DPPH, and ABTS were found among different concentrations of GP. Cream soup supplemented with GP 10% exhibited the highest values for DPPH and ABTS (83.5% and 87%, respectively), while the contents of total phenolic and saponin were 0.651 ± 0.02 (mg Gallic acid Equiv./g, DW) and 0.797 ± 0.05 (mg Diosgenin Equiv./g, DW), respectively. Moreover, there were no significant changes for °Brix value, pH, acidity, and total flavonoids content compared to control. The sensory characteristics indicated bitterness with the increase in the concentration of GP. However, a non-significant difference was observed between the control and supplemented samples for color, viscosity, and overall preference. Therefore, the supplementation of GP to cream soup could exhibit health benefits and increase the demand for ginseng to promote public health as functional food material

Sensitivity Comparison of Open-Circuit Airgap Flux Between Surface-Mounted Permanent Magnet and Spoke-Type Permanent Magnet Machines Considering Manufacturing Tolerances

The study compares the sensitivities of open-circuit airgap flux (OCAF) between a surface-mounted permanent magnet (SPM) machine and a spoke-type PM machine based on variations in airgap length including additional airgaps between permanent magnets and rotor core and between segmented stator cores to achieve high quality electric machines. Analytical equations deduced from magnetic equivalent circuits (MECs) are used to directly compare natural-born characteristics of the OCAF of the two machines. First, the MEC of each machine is modeled by considering two additional airgaps between the PMs and rotor core and between the segmented stator cores. Second, the OCAF equation of each machine is derived from the MEC to analyze the effects of the design variables on the OCAF. Subsequently, the partial derivative equation of the OCAF equation with respect to the airgap length is obtained for sensitivity analysis. A comparison of the equations of the two machines indicates that the spoke-type PM machine exhibits inherently higher sensitivity and average value of the OCAF when compared to that of the SPM machine. Finally, the results are validated via a two-dimensional finite element method (FEM) by considering the variations in airgap lengths

Triage results of children who visited the emergency department via emergency medical service providers: an observational study in a regional emergency medical center

Purpose We aimed to investigate the triage results and the degree of agreement between prehospital and hospital stages of pediatric patients who visited the emergency department (ED) via emergency medical service providers (EMSP) in comparison with adult patients. Methods We retrospectively reviewed 8,152 pediatric patients who visited a regional emergency medical center ED via EMSP from January 2015 to December 2015. Pediatric patients were defined as younger than 15 years according to the Korean Triage and Acuity Scale (KTAS). Given the difference of the triage tools of the prehospital (EMSP) and hospital (KTAS) stages, we performed the re-triage into “critical” and “non-critical”. Comparisons of characteristics between pediatric and adult patients were made using chi-square tests. The degree of agreement between the tools was analyzed using κanalysis. Results Of 8,152 patients, 654 (8.0%) were pediatric patients. Direct medical control was more frequently performed to adult patients (P < 0.001). Critical patients were more common among adults (12.2% by KTAS, 24.8% by EMSP) than children (3.5% by KTAS, 14.1% by EMSP). The κ value of pediatric patients was lower than that of adult patients (0.09 [poor]; 95% confidence interval [CI], 0.01-0.18 vs. 0.38 [fair]; 95% CI, 0.35-0.40). Conclusion Pediatric patients transferred by EMSP showed lower severity and degree of agreements of the triage results between prehospital and hospital stages than adult patients. It is necessary to pay particular attention to pediatric triage in a pre-hospital setting

IgA and Differentiation-associated Transcription Factors in Chronic Otitis Media with Effusion

ObjectivesInadequate antibody responses to pathogens may lead to the recurrence of otitis media with effusion (OME). Although B-cell production by antibodies is controlled by transcription factors, the status of these factors has not been assessed in patients with OME.MethodsExpression of immunoglobulin was measured by enzyme-linked immunosorbent assay. Expression of transcription factors Bcl-6, Blimp-1, Pax-5, and XBP-1 was assessed by RT-PCR in the middle-ear fluid of 29 children with >4 OME episodes in 12 months or >3 episodes in 6 months (the OME-prone group) and in 32 children with <3 OME episodes in 12 months (OME group). The relationship between recurrence of OME and expression levels of immunoglobulins and transcription factors in middle-ear fluid was determined.ResultsThe concentration of IgA in middle-ear fluid was significantly lower in the OME-prone than in the OME group, as was the expression of mRNA encoding the transcription factors Blimp-1 and XBP-1 (P<0.05 each). Expression of mRNA encoding the transcription factors Bcl-6 and Pax-5 was more intense in the OME-prone than in the OME group, but these differences were not significant (P>0.05).ConclusionLower concentrations of IgA, Blimp-1 and XBP-1 in middle ear fluid of patients with OME may be related to OME recurrence and chronicity

Decreased Pattern-Recognition Receptor-Mediated Cytokine mRNA Expression in Obese Children With Otitis Media With Effusion

ObjectivesTo assess innate and humoral immune responses in middle ear effusion of obese pediatric patients with otitis media with effusion (OME).MethodsWe evaluated 219 children with OME, of whom 21 were obese and 198 were non-obese. We compared the expression in middle ear effusion of mRNAs encoding toll-like receptors (TLR) 2, 4, 5, and 9; nucleotide-binding oligomerization domains (NOD) 1 and 2; retinoic acid-inducible gene (RIG)-I; interleukins (IL)-6, -10, and -12; interferon (IFN)-γ; and tumor necrosis factor (TNF)-α mRNAs. We also compared the expression of immunoglobulins IgG, IgA, and IgM and the bacterial detection rate in the two groups.ResultsTLR2-mediated expression of IL-6 mRNA, TLR4-mediated expression of IL-6 and IL-10 mRNA, TLR5-mediated expression of IL-6, IL-10, and TNF-α mRNA, TLR9-mediated expression of IL-6 mRNA, and NOD2-mediated expression of IL-6, IL-12, and TNF-α mRNA were significantly lower in obese than in non-obese children (P0.05).ConclusionMean body mass index was higher and pattern-recognition receptor-mediated cytokine mRNA expression was lower in obese than in non-obese children with OME

Toll-like Receptors 2 and 4 and Their Mutations in Patients with Otitis Media and Middle Ear Effusion

ObjectivesToll-like receptors (TLRs) detect microbial infections and they can directly induce innate host defense responses. TLR 2 has been shown to be primarily involved in the recognition of peptidoglycans and lipoteichoic acid of gram positive bacteria. TLR 4 recognizes lipopolysaccharides and lipoteichoic acids from both gram-negative and gram-positive bacteria. Both mutations lead a reduced capacity to elicit inflammation and they increase the risk for gram-positive and negative infections. This study was performed to investigate the expressions of TLR 2 and 4 and their mutations in patients suffering with otitis media and middle ear effusion.MethodsMiddle ear fluid samples were collected from 40 otitis media effusion (OME) patients who had ventilating tubesinserted. Bacteria in the effusion fluid were detected by standard bacterial culture. The secreted IgG, IgA and IgM were measured by Enzyme-linked immunosorbent assay. TLR 2 and 4 were assessed by performing RT-PCR. The genomic DNA from each patient was isolated from the middle ear fluid samples that were collected from 60 OME patients, and the presence of mutations was determined by performing restriction digestion and DNA sequencing analysis.ResultsAmong the 40 middle ear fluid samples, bacteria were detected in 13 middle ear fluid samples. The amounts of IgM, IgA, and IgG were 151.20±60.94 ng/mL, 21.59±7.96 ng/mL and 11.55±16.98 ng/mL, respectively. TLR 2 and 4 were expressed in the middle ear fluid and the expression of TLR 2 was higher than that of TLR 4. However, there was no correlation between the expressions of TLR 2 and 4, and the concentration of immunoglobulin or the presence of bacteria (P>0.05). There ware no mutations of TLR 2 (Arg753Gln, Arg677Trp) and TLR 4 (Asp299Gly, Thr399Ile).ConclusionTLR 2 and 4 were expressed in all the middle ear fluid samples of OME, but the mutations of TLR 2 and 4 were not detected. TLR 2 and 4 may play a vital role in the immunological responses of patients with OME