Predictive direct torque control of permanent magnet synchronous motors using deadbeat torque and flux control

Ao Wang,Housheng Zhang,Junjie Jiang,Duo Jin,Shengjie Zhu 전력전자학회 2023 JOURNAL OF POWER ELECTRONICS Vol.23 No.2

In consideration of the shortcomings of the large torque and flux ripples in direct torque control (DTC), and the insufficient utilization of the duty cycle module in traditional DTC based on the duty cycle modulation of PMSMs, a DTC method based on deadbeat control of the torque and flux is proposed in this paper. In the synchronous rotation, coordinate system positioned with the stator flux vector, the reference voltage vector is calculated in accordance to the deadbeat control method. Six virtual voltages are constructed in such a manner that two adjacent basic voltage vectors are evenly divided in one control cycle. The effective voltage vectors are expanded to 12. The effective voltage vector closest to the phase angle of the reference voltage vector is determined to be the optimal voltage vector. Then, the duty cycle is introduced to further reduce the error between the final output voltage vector and the voltage vector required by the system. Simulation comparisons are carried out for DTC, traditional DTC based on duty cycle modulation, and the proposed DTC. The obtained simulation results demonstrate that the proposed DTC can effectively suppress both torque ripple and flux ripple, improve the utilization rate of the duty cycle module, and reduce the stator current distortion rate.

A Study of The Usage of Travel-related WeChat Mini Programs

Ao Cheng,Namho Chung,Chulmo Koo 한국경영정보학회 2019 한국경영정보학회 학술대회논문집 Vol.2019 No.5

Purpurogallin Protects Keratinocytes from Damage and Apoptosis Induced by Ultraviolet B Radiation and Particulate Matter 2.5

( Ao Xuan Zhen ),( Mei Jing Piao ),( Yu Jae Hyun ),( Kyoung Ah Kang ),( Yea Seong Ryu ),( Suk Ju Cho ),( Hee Kyoung Kang ),( Young Sang Koh ),( Mee Jung Ahn ),( Tae Hoon Kim ),( Jin Won Hyun ) 한국응용약물학회 2019 Biomolecules & Therapeutics(구 응용약물학회지) Vol.27 No.4

Purpurogallin, a natural phenol obtained from oak nutgalls, has been shown to possess antioxidant, anticancer, and anti-inflammatory effects. Recently, in addition to ultraviolet B (UVB) radiation that induces cell apoptosis via oxidative stress, particulate matter 2.5 (PM_2.5) was shown to trigger excessive production of reactive oxygen species. In this study, we observed that UVB radiation and PM_2.5 severely damaged human HaCaT keratinocytes, disrupting cellular DNA, lipids, and proteins and causing mitochondrial depolarization. Purpurogallin protected HaCaT cells from apoptosis induced by UVB radiation and/or PM_2.5. Furthermore, purpurogallin effectively modulates the pro-apoptotic and anti-apoptotic proteins under UVB irradiation via caspase signaling pathways. Additionally, purpurogallin reduced apoptosis via MAPK signaling pathways, as demonstrated using MAPK-p38, ERK, and JNK inhibitors. These results indicate that purpurogallin possesses antioxidant effects and protects cells from damage and apoptosis induced by UVB radiation and PM_2.5.

Effects of Dietary Additives and Early Feeding on Performance, Gut Development and Immune Status of Broiler Chickens Challenged with Clostridium perfringens

Ao, Z.,Kocher, A.,Choct, M. Asian Australasian Association of Animal Productio 2012 Animal Bioscience Vol.25 No.4

The effects of dietary additives and holding time on resistance and resilience of broiler chickens to Clostridium perfringens challenge were investigated by offering four dietary treatments. These were a negative control (basal), a positive control (Zn-bacitracin) and two dietary additives, mannanoligosaccharides (MOS), and acidifier. Two holding times included (a) immediate access to feed and water post hatch (FED) and (b) access to both feed and water 48 h post hatch (HELD). Chicks fed Zn-bacitracin had no intestinal lesions attributed to necrotic enteritis (NE), whereas chicks fed both MOS or acidifier showed signs of NE related lesions. All dietary treatments were effective in reducing the numbers of C. perfringens in the ileum post challenge. The FED chicks had heavier body weight and numerically lower mortality. The FED chicks also showed stronger immune responses to NE challenge, showing enhanced (p<0.05) proliferation of T-cells. Early feeding of the MOS supplemented diet increased (p<0.05) IL-6 production. The relative bursa weight of the FED chicks was heavier at d 21 (p<0.05). All the additives increased the relative spleen weight of the HELD chicks at d 14 (p<0.05). The FED chicks had increased villus height and reduced crypt depth, and hence an increased villus/crypt ratio, especially in the jejunum at d 14 (p<0.05). The same was true for the HELD chicks given dietary additives (p<0.05). It may be concluded that the chicks with early access to dietary additives showed enhanced immune response and gut development, under C. perfringens challenge. The findings of this study shed light on managerial and nutritional strategies that could be used to prevent NE in the broiler industry without the use of in-feed antibiotics.

Ultimate torsional strength of cracked stiffened box girders with a large deck opening

Ao, Lei,Wang, De-Yu The Society of Naval Architects of Korea 2016 International Journal of Naval Architecture and Oc Vol.8 No.4

The present paper studies the ultimate torsional strength of stiffened box girders with large deck opening due to the influence of cracks. Three types of hull girders with different spans are provided for comparison. Potential parameters which may have effects on the torsional strength including the mesh refinement, initial deflection, material strain hardening, geometric properties of crack and stiffener are discussed. Two new concepts that play an significant role in the ultimate strength research of damaged box girders are introduced, one of which is the effective residual section (ERS), the other is the initial damage of the failure zone (IDFZ) for intact structures. New simple formulas for predicting the residual ultimate torsional strength of cracked stiffened box girders are derived on the basis of the two new concepts.

Effects of Diet Complexity and Fermented Soy Protein on Growth Performance and Apparent Ileal Amino Acid Digestibility in Weanling Pigs

Ao, X.,Kim, H.J.,Meng, Q.W.,Yan, L.,Cho, J.H.,Kim, I.H. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.11

Two experiments were conducted to evaluate the effects of diet complexity and fermented soy protein on growth performance and amino acid digestibility. In Exp. 1, a total of 120 crossbred weanling pigs ($5.68{\pm}0.80\;kg$ BW) were randomly allocated into 4 treatments. Each treatment had 6 replicate pens comprising 5 pigs in each replicate. Experimental diets consisted of simple (soybean meal as protein source) and complex (soybean meal, rice protein concentrate, potato protein concentrate and fish meal as protein sources) diets; each diet contained 0 or 5% fermented soy protein (FSP), respectively. Dietary treatments included: i) simple diet; ii) simple diet with 5% FSP; iii) complex diet; iv) complex diet with 5% FSP. Pigs were provided each experimental diet for 20 d (phase 1) and then fed the same common diet for 10 d (phase 2). During days 0-10, pigs fed FSP diets had greater ADG than those fed non-FSP diets (p<0.05). G/F in FSP treatments was significantly higher than that in non-FSP treatments (p<0.05) from days 0 to 10. Throughout the overall period, G/F was greater in FSP treatments compared with non-FSP treatments (p<0.05). On d 10, N digestibility was higher in pigs fed FSP diets than in those fed non-FSP diets (p<0.05). Diet complexity did not affect growth performance and nutrient digestibility (p>0.05) in this experiment. In Exp 2, 12 ileal-cannulated, weanling barrows were housed in individual metabolism crates and randomly assigned to 1 of 4 treatments (same as Exp. 1) by using a $4{\times}4$ Latin square design. Among the essential amino acids, apparent ileal digestibility (AID) of Met and Val were increased in pigs fed FSP diets compared with those fed non-FSP diets (p<0.05). AID of Met, Phe and total essential amino acids were higher in pigs fed complex diets than in those fed simple diets (p<0.05). Among the non-essential amino acids, AID of Ala in FSP treatments was greater than that in non-FSP treatments (p<0.05). In addition, Asp, Cys, Glu, Pro, Ser and total non-essential amino acid digestibilities in pigs fed complex diets were higher compared with those fed simple diets (p<0.05). Interaction was observed in AID of Met, Asp and Pro. In conclusion, these results indicated that feeding of 5% FSP to nursery pigs improved feed efficiency and AID of amino acids, and diet complexity did not maximize the growth performance of pigs in the subsequent phase.

Effects of Fermented Garlic Powder on Production Performance, Egg Quality, Blood Profiles and Fatty Acids Composition of Egg Yolk in Laying Hens

Ao, X.,Yoo, J.S.,Lee, J.H.,Jang, H.D.,Wang, J.P.,Zhou, T.X.,Kim, I.H. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.6

The effects of fermented garlic powder on production performance, egg quality, blood profiles and fatty acid composition of egg yolk in laying hens were studied in a 35-d experiment. Two-hundred and forty (ISA brown) layers aged 41 weeks were randomly allocated into the following four treatments: i) CON (basal diet); ii) G1 (CON+fermented garlic powder 1.0%); iii) G2 (CON+fermented garlic powder 2.0%) and iv) G3 (CON+fermented garlic powder 3.0%). There were no differences (p>0.05) among treatments in egg production, egg weight, eggshell breaking strength and eggshell thickness throughout the whole experimental period. However, yolk height was increased significantly (p<0.05) by the addition of fermented garlic powder during the 5th week while yolk color was greater (p<0.05) in G2 and G3 than in CON and G1 in the 5th week. Compared with CON, Haugh unit was increased (p<0.05) in response to fermented garlic powder treatments during the 5th week. No significant effects on total protein, albumin and IgG were observed in response to any of the treatments over the experimental period (p>0.05). There was a significant (p<0.05) reduction in plasma cholesterol concentration when the dietary level of fermented garlic powder was increased from 0.0 to 3.0%. The levels of saturated fatty acids (SFA) were significantly decreased (p<0.05) in response to G2 and G3 while monounsaturated fatty acids (MUFA) were higher (p<0.05) in G2 and G3 treatment groups than in CON and G1. Compared with other treatments, polyunsaturated fatty acids (PUFA) and PUFA:SFA ratio were higher (p<0.05) in G3. In conclusion, this study demonstrated that addition of fermented garlic powder reduced plasma cholesterol concentration and did not cause adverse effects on production performance. Moreover, addition of 3.0% garlic powder decreased SFA but increased PUFA and PUFA:SFA ratio in egg yolk.

Effects of Non-starch Polysaccharide-degrading Enzymes on Nutrient Digestibility, Growth Performance and Blood Profiles of Growing Pigs Fed a Diet Based on Corn and Soybean Meal

Ao, X.,Meng, Q.W.,Yan, L.,Kim, H.J.,Hong, S.M.,Cho, J.H.,Kim, I.H. Asian Australasian Association of Animal Productio 2010 Animal Bioscience Vol.23 No.12

Two experiments with growing pigs were conducted to investigate the effects of two distinct multienzyme preparations on nutrient digestibility, growth performance and blood profiles. In Exp. 1, a total of 96 pigs ($29.7{\pm}0.69\;kg$) were utilized in a 42-day performance and digestibility trial using four dietary treatments: CON (control diet), ENDO (control+0.10% Endopower), NSPase1 (control+0.10% NSPase) and NSPase2 (control+0.20% NSPase). Endopower was a commercial multienzyme preparation which contained ${\alpha}$-galactosidase, galactomannase, xylanase and ${\beta}$-glucanase. NSPase mainly contained ${\alpha}$-1,6-${\beta}$-galactosidase, ${\beta}$-1,4-mannanase and ${\beta}$-1,4-mannosidase. There were six replication pens per treatment with four pigs per pen. Pigs fed NSPase1 diet had a higher ADG (p<0.05) and G:F (p<0.05) than those fed the control diet. There were no significant differences in growth performance among the multienzyme treatments (p>0.05). Compared with CON, apparent digestibility of DM was increased (p<0.05) by ENDO treatment. N digestibility was improved (p<0.05) in response to multienzyme treatments during the experimental period. Blood urea nitrogen (BUN) was higher (p<0.05) in ENDO treatment than in CON and NSPase1 treatments at the end of the experiment, while the glucose level improved (p<0.05) due to ENDO and NSPase2 treatments. In Exp. 2, four ileal-cannulated, growing barrows ($20.17{\pm}1.31\;kg$) were housed in individual metabolism crates and randomly assigned to 1of 4 treatments (same as Exp. 1) within a $4{\times}4$ Latin square design. Enzyme supplementations improved the majority of apparent ileal amino acid digestibilities (p<0.05). It is concluded that the supplementation of NSPase1 improved growth performance as well as N digestibility and partially improved apparent ileal amino acid digestibility in growing pigs fed a diet based on corn and soybean meal.

Differences in foot shape when wearing wedge-heeled shoes with elevated forefoot height and heel height

Ao Zhu,Yu-Chi Lee 한국의류학회 2023 Fashion and Textiles Vol.10 No.1

Wedge-heeled shoes, which are formed by elevating both the forefoot and heel, have been popular among young women. However, research on the foot shape in wedge-heeled shoes is lacking. This study aimed to access the effects of forefoot height (10, 20, and 30 mm) and heel height (30, 50, 70, and 90 mm) on foot shape and perceived comfort when wearing wedge-heeled shoes. Three-dimensional (3D) foot scanning was performed on 35 females and the 14 foot dimensions were measured. Increased forefoot height generated larger lengths (foot, ball and out ball), smaller girths (ball and instep) and heights (instep and navicular) ( p < 0.05). Thus, when the forefoot height increased, the foot became longer, slimmer and flatter. Moreover, elevated heel height resulted in larger dimensions for girths (ball and instep), heights (instep and navicular), and smaller dimensions for lengths (foot, ball and out ball), widths (diagonal and horizontal) and toe 5 angles of the foot ( p < 0.01). That means shorter, narrower and more convex foot shapes were observed when heel height increased. Subjective measurements implied that increased forefoot height significantly enhanced perceived comfort, whereas increased heel height diminished comfort. It was found that forefoot elevation could result in less deformation and discomfort which accompanied heel elevation, especially in the low heel-toe drop combinations (10 × 30 and 20 × 30 mm). The findings provide valuable references for enhancing shoe fitting and comfort for wedge-heeled shoes by providing dimensional data on the toe, ball, arch and instep regions.

IL-17A exacerbates diabetic retinopathy by impairing Müller cell function via Act1 signaling

Ao-Wang Qiu,Zheng Bian,Ping-An Mao,Qing-Huai Liu 생화학분자생물학회 2016 Experimental and molecular medicine Vol.48 No.-

Diabetic retinopathy (DR), one of the most serious complications of diabetes, has been associated with inflammatory processes. We have recently reported that interleukin (IL)-17A, a proinflammatory cytokine, is increased in the plasma of diabetic patients. Further investigation is required to clarify the role of IL-17A in DR. Ins2Akita (Akita) diabetic mice and high-glucose (HG)-treated primary Müller cells were used to mimic DR-like pathology. Diabetes induced retinal expression of IL-17A and IL-17 receptor A (IL-17RA) in Müller cells in contrast to ganglion cells. Further evidence demonstrated that retinal Müller cells cultured in vitro increased IL-17A and IL-17RA expression as well as IL-17A secretion in the HG condition. In both the HG-treated Müller cells and Akita mouse retina, the Act1/TRAF6/IKK/NF-κB signaling pathway was activated. IL-17A further enhanced inflammatory signaling activation, whereas Act1 knockdown or IKK inhibition blocked the downstream signaling activation by IL-17A. HG- and diabetesinduced Müller cell activation and dysfunction, as determined by increased glial fibrillary acidic protein, vascular endothelial growth factor and glutamate levels and decreased glutamine synthetase and excitatory amino acid transporter-1 expression, were exacerbated by IL-17A; however, they were alleviated by Act1 knockdown or IKK inhibition. In addition, IL-17A intravitreal injection aggravated diabetes-induced retinal vascular leukostasis, vascular leakage and ganglion cell apoptosis, whereas Act1 silencing or anti-IL-17A monoclonal antibody ameliorated the retinal vascular damage and neuronal cell apoptosis. These findings establish that IL-17A xacerbates DR-like pathology by the promotion of Müller cell functional impairment via Act1 signaling.