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Neuroimaging studies have revealed how intrinsic dysconnectivity among cortical regions of the mentalizing network (MENT) and the mirror neuron system (MNS) could explain the theory of mind (ToM) deficit in schizophrenia patients. However, despite the concurrent involvement of the cerebellum with the cortex in social cognition, the dysfunction in intrinsic interplay between the cerebellar nodes of MENT/MNS and the cortex in schizophrenia patients remains unknown. Thus, we aimed to investigate whether resting-state cerebello–cortical dysconnectivity exists in first-episode psychosis (FEP) patients in relationship with their ToM deficit. A total of 37 FEP patients and 80 healthy controls (HCs) underwent resting-state functional magnetic resonance imaging. Using a priori-defined cerebellar seeds that functionally connect to the MENT (right crus II) and MNS (right crus I), we compared cerebello–cortical functional connectivities (FCs) in FEP patients and HCs. Correlations between cerebello–parietal connectivities and ToM performance were investigated in FEP patients. FEP patients showed hyperconnectivity between the right crus II and anterior cingulate gyrus and between the right crus I and supplementary motor area, bilateral postcentral gyrus, and right central/parietal operculum (CO/PO). Hypoconnectivity was found between the right crus II and left supramarginal gyrus (SMG) in FEP patients. FCs between the right crus II and left SMG and between the right crus I and right CO/PO were significantly correlated with ToM scores in FEP patients. In accordance with the “cognitive dysmetria” hypothesis, our results highlight the importance of cerbello-cortical dysconnectivities in understanding social cognitive deficits in schizophrenia patients.

Electric vehicle (EV) systems require a high energy-efficiency traction motor so that the motors for EV traction should achieve high efficiency and power density. Hence, a permanent magnet synchronous motor (PMSM) for EV traction using a maximum slot occupation (MSO) coil has been investigated in this study. By applying the MSO coil, high torque density was achieved, but an additional loss, which decreases the efficiency, was incurred through alternating current (AC) resistance. To reduce the AC resistance of the MSO coil, the following process was performed: First, by investigation using the analytical method, pole/slot numbers, current density and number of parallel circuits affecting the frequency, the shape and number of conductors were chosen as important variables. Resistances of the MSO coil with a stator core were analyzed according to the chosen variables above. From the results, MSO coil applied PMSM with proper pole/slot numbers, current density, and parallel circuits was determined to improve the efficiencies at the base and maximum speeds. To accurately estimate the efficiency of the determined model, loss evaluation methods were explained. Subsequently, the determined MSO coil applied model was compared with the conventional model having round wires, and the improvements were verified by load testing.

This paper presents a model predictive control (MPC) based harmonic current injection method (HCIM) to suppress the torque ripple caused by misalignment in gearbox. As it is inefficient to determine the amplitude and phase of harmonic currents manually, the MPC is used to search the appropriate harmonic currents to implement HCIM efficiently. A cost function for MPC is designed to minimize a resultant torque ripple which is calculated by summing the misalignment torque ripple and compensation torque. The compensation torque is an input variable of the predictive model. In order to predict the resultant torque ripple accurately, an estimation method of the misalignment torque ripple with torque sensor is also proposed. The calculated compensation torque is converted into harmonic currents and the harmonic currents can be injected into a q -axis current. As a result, the misalignment torque ripple can be suppressed. Experimental results demonstrate verification for estimation method of misalignment torque ripple, and effectiveness of the HCIM. In addition, the proposed MPC-HCIM is also verified by experiments, and the misalignment torque ripple is effectively suppressed by using the proposed method. By using the proposed method, high degree of precision in torque control can be achieved with low quality gearbox which has misalignment.

To improve electric vehicle (EV) mileage, motors must be designed for higher power density and efficiency. Winding technology with a high fill factor decreases the motor volume by reducing the unnecessary area of the slot. A motor conductor with a large cross-sectional area generates additional losses due to ac resistance, reducing the efficiency of the motor. Traction motors designed under these conditions can adversely affect EV fuel economy. Therefore, a design method is proposed to reduce the ac resistance of a traction motor by applying winding technology with a high fill factor to increase the fuel economy of the EVs. First, the characteristics and manufacturing process of the maximum slot occupation (MSO) coil, which is a winding technology with a high fill factor, are introduced. An ac resistance reduction method for a motor using an MSO coil is then proposed. Additionally, a motor designed using the proposed method is presented, and its electrical performance is compared with that of an initial motor. Next, the effect of the fuel economy improvement of the presently designed traction motor is verified through a vehicle simulation, and the validity of this article is experimentally confirmed using this motor.

The accuracy of motor characteristics prediction according to driving cycle can be improved by taking temperature change of motor into account. From this point of view, this paper proposes a fast and accurate coupled analysis method. To calculate motor circuit parameters, electromagnetic finite element analysis (FEA) is used. The proposed method consists of two stages to exclude the time consuming FEA from repetitive process. In pre-process stage, the circuit parameters are stored as look-up tables (LUTs) considering motor temperature. Further, a technique that allows reducing the number of analyses is developed to consider a wide operating temperature range with less time consumption. In main process stage, the torque and voltage equations are solved using the circuit parameter LUTs. Among the solved motor characteristics, losses are applied to lumped parameter thermal network (LPTN) as heat sources to figure out thermal characteristics. Here, techniques including loss separation and thermal parameter tuning are introduced to improve both accuracy and speed of the LPTN. Since the computation of the characteristic equations and LPTN are fast, the iterative analysis at entire time steps of the driving cycle is facilitated. An example of the proposed method is presented using worldwide harmonized light vehicle test procedure (WLTP). Thereafter, the effectiveness of the method is discussed by comparison with conventional methods. Finally, the experimental verifications are conducted to validate the electromagnetic FEA and LPTN used in this study.

This article proposes an indirect method for predicting mechanical loss by considering the eddy current loss of permanent magnets (PMs) and conductors under the no-load condition. The mechanical loss has been conventionally predicted indirectly through experiments and numerical methods. The conventional method uses the no-load loss measured through experiments and the no-load iron loss calculated through a numerical method. With the increase in the demand for high-power-density motors, the PMs with high energy density and winding technology with high fill factor are required. Thus, the proportion of eddy current losses of PMs and conductors is increasing among the electromagnetic losses. Therefore, we propose an indirect method for predicting the mechanical loss considering the eddy current losses. The accuracy of the proposed method is higher than that of the conventional method. Moreover, the proposed method is verified by comparing the estimated efficiency of the specimen obtained by using this method with the measured efficiency.

This article proposes a design method for a high-speed response motor system consisting of a motor and load. Various methods have been studied to improve the speed response of the motor system, but the main focus was previously advanced control techniques. However, the dynamic response of the controller can be further improved with the high-speed response motor system. The proposed method improves the speed response by increasing the bandwidth of the motor system, which is the plant of the servo system. Thus, the relationship between the bandwidth, which is an indicator of speed response and the motor system, is investigated. The motor system consists of the electrical and mechanical parameters. As both electrical and mechanical parameters affect the speed response and bandwidth of the motor system, the correlation of the time constants and bandwidth is analyzed. Based on the analyzed results, the process of designing a motor system with maximized bandwidth is introduced. An experimental based friction model is proposed to estimate the accurate speed responses and required torque of the motor system. Therefore, a motor system with maximized bandwidth is designed using the proposed design process and friction model. Finally, the rated power and speed response of the motor system are verified through simulations and experiments.

Background Extracellular vesicle (EV)–mimetic nanovesicles (NVs) from embryonic stem cells have been observed to stimulate neurovascular regeneration in the streptozotocin-induced diabetic mouse. Pericytes play important roles in maintaining penile erection, yet no previous studies have explored the effects of pericyte-derived NVs (PC-NVs) in neurovascular regeneration in the context of erectile dysfunction. Aim To investigate the potential effect of PC-NVs in neurovascular regeneration. Methods PC-NVs were isolated from mouse cavernous pericytes, and neurovascular regeneration was evaluated in an in vitro study. Twelve-week-old C57BL/6J mice were used to prepare cavernous nerve injury model. Erectile function evaluation, histologic examination of the penis, and Western blots were assessed 2 weeks after model creation and PC-NVs treatment. Outcomes The main outcomes of this study are PC-NVs characterization, intracavernous pressure, neurovascular regeneration in the penis, and in vitro functional evaluation. Results The PC-NVs were extracted and characterized by cryotransmission electron microscopy and EV-positive (Alix, TSG101, CD81) and EV-negative (GM130) markers. In the in vivo studies, PC-NVs successfully improved erectile function in cavernous nerve injury mice (∼82% of control values). Immunofluorescence staining showed significant increases in pericytes, endothelial cell, and neuronal contents. In the in vitro studies, PC-NVs significantly increased mouse cavernous endothelial cells tube formation, Schwann cell migration, and dorsal root ganglion and major pelvic ganglion neurite sprouting. Finally, Western blot analysis revealed that PC-NVs upregulated cell survival signaling (Akt and eNOS) and induced the expression of neurotrophic factors (brain-derived neurotrophic factor, neurotrophin-3, and nerve growth factor). Clinical Implications PC-NVs may be used as a strategy to treat erectile dysfunction after radical prostatectomy or in men with neurovascular diseases. Strengths & Limitations We evaluated the effect of PC-NVs in vitro and in a mouse nerve injury model, cavernous nerve injury. Additional studies are necessary to determine the detailed mechanisms of neurovascular improvement. Further study is needed to test whether PC-NVs are also effective when given weeks or months after nerve injury. Conclusion PC-NVs significantly improved erectile function by enhancing neurovascular regeneration. Local treatment with PC-NVs may represent a promising therapeutic strategy for the treatment of neurovascular diseases.

In this study we developed a brushless DC (BLDC) slotless motor with toroidal winding. The proposed toroidal winding is a method of winding a coil around a ring-type stator yoke in the circumferential direction. As there is no need for a slot or tooth structure, it can be designed with a slotless motor structure that is advantageous for vibration and noise. The basic principle of operation and motor characteristics of a slotless motor with toroidal winding were explained using an analytical method and finite element analysis (FEA). Further, the air gap flux density, winding factor, and back electromotive force (EMF) for changes in the winding angle and number of coil turns were calculated using the analytical method and compared with the FEA results. Finally, the resistance, back EMF, cogging torque, and performance of the prototype were measured and compared with the FEA results. The results show that the air gap flux density and winding factor were approximately the same with an error of &lt, 2%, while the back EMF had an error of ~10% from the analysis result. Thus, the proposed slotless motor provides a basic design for conveniently manufacturing brushless DC (BLDC) slotless motors with toroidal windings.

For high power density, a winding technology which has large conductor area such as hairpin winding has been adopted in interior permanent magnet synchronous motor (IPMSM) for applications such as electric vehicle (EV) traction. However, as the conductor area increases, the influence of AC copper loss should be considered. This paper presents the effect of AC copper loss caused by field and armature excitation on the characteristics of IPMSM. In order to calculate the AC copper loss due to field and armature excitation, a method of separating the AC copper loss using frozen permeability is presented. In addition, novel d, q-axis equivalent circuits are presented to consider the AC copper loss due to each cause in calculation of characteristics of IPMSM.

Static eccentricity (SE) is frequently generated by manufacturing processes. As the nonuniformity of the air-gap length is caused by the SE, the torque ripple and cogging torque increase in the motor. This study analyzes the distorted back electromotive force (EMF) and cogging torque due to SE. Further, a motor design considering SE is performed for stable back EMF and low cogging torque. First, the SE was diagnosed and analyzed using the back EMF and cogging torque measured from the test results of the base model. In addition, the rotor position was calculated using the unbalanced back EMF due to the SE. The calculated rotor position is used when analyzing phenomena due to SE and applied to robust design. Subsequently, robust design optimization was performed to improve the unbalanced back EMF and cogging torque due to SE. Using finite element analysis (FEA) considering SE, the shape of the stator was designed based on the base model. The estimated rotor position from the base model was applied to the optimum model to confirm its robustness from SE’s effects. Finally, the base and optimum models were compared through the test results.

It is so important that the bonding technology between tungsten and dissimilar metals for the PFC of ITER and DEMO, KSTAR. The development of tungsten brazing technology was first launched for the KSTAR PFC. Flat type tungsten block was brazed on CuCrZr in vacuum at a temperature of 980 °C for 30 min using silver free brazing alloy. The brazing filler is a 0.05 mm thick-plate made of a Ni-Cu-Mn alloy. Tungsten brazed mock-ups with a swirl and smooth tube were tested at an electron beam facility, KoHLT-EB(Korea heat load test facility-Electron Beam) in KAERI. The high heat flux test was performed for tungsten brazed mock-ups with a swirl and smooth tube under the heat flux of about 5.4–8 MW/m2. The test results show there are no delamination or failures at the bonding joints during and after all the heat flux test. According to the thermal hydraulic analysis and results of heat flux test, the cooling effect of the smooth tube was better than one of the swirl tube at the conditions of the coolant of about 0.35 MPa and the heat flux of over about 5 MW/m2.

The paper presents high frequency pellet injectors developed for edge localized mode mitigation and plasma fuelling of the EAST and KSTAR tokamaks. Each pellet injector is able to inject solid deuterium or hydrogen pellets at steady state mode. Injectors consist of modules including screw extruder cooled by liquid helium and pneumatic punchers for pellet fabrication and acceleration which are optimized to reach maximal injection frequency for specified pellet parameters. The EAST pellet injector is capable of injecting 1.5 mm diameter and 1.2–1.8 mm length pellets at frequency up to 50 Hz with velocities 200–250 m/s using two injection modules working in an alternating mode at 25 Hz each. Injection reliability over 90% has been confirmed during several cycles of continuous D2 pellet injection at 50 Hz. The KSTAR pellet injector has been designed to inject 2 mm size pellets at frequency up to 20 Hz and velocity 200 m/s. Due to improved design of pellet fabrication and acceleration system the world record in continuous injection of 20,164 deuterium pellets (O2.0 × 1.5 mm) for 1039 s at 20 Hz with reliability 97% has been achieved.

KSTAR (Korea Superconducting Tokamak Advanced Research) has used a gas puffing system as a main fueling method since 2008. Up to date total fueling efficiency of the gas puff is less than 30%. A pellet injection is a more effective technique to control a plasma density than the gas puffing system and a supersonic molecular beam injection. Therefore, we have developed the pellet injection system for KSTAR. The pellet injection system for KSTAR consists of a pellet injector which injects pellets of a deuterium (diameter of 2 mm, length of 1.5–2 mm) at a velocity above 200 m/s with an injection frequency of 1–20 Hz, a 2-stage differential pumping system, a guide tube, a control system and so on. It is planned to inject pellets through a high field side and increase the plasma performance.

This paper deals with the design process for an outer-rotor-type surface-mounted permanent magnet synchronous motor (SPMSM) used in continuous variable valve timing (CVVT) systems in automobiles with internal combustion engines. When the same size, outer-rotor-type SPMSMs generate larger torque and more stable than inner-rotor-type SPMSMs. For the initial design, space harmonic analysis (SHA) is used. In order to minimize the cogging torque, an optimization was conducted using Response Surface Methodology (RSM). At the end of the paper, Finite Element Analysis (FEA) is performed to verify the performance of the optimum model.

As the EV traction system requires the PMSM to be driven at wide driving range, the PMSM for EV traction using Maximum Slot Occupation coil (MSO coil) has been designed in this paper. By applying the MSO coil, the high torque density was satisfied but additional loss by AC resistance at high speed became critical. In order to reduce the AC resistance of MSO coil, the following process was conducted. First, by analyzing the analytic method, the shape and number of conductor which depend on the current density and parallel circuit were chosen as the important parameter on AC resistance. By investigating the MSO coil with E-I core, the resistances of MSO coil at both low and high frequency were studied according to current density and parallel circuit. Based on the results above, the PMSM using MSO coil was designed in proper current density and parallel circuit to improve the efficiency at both base and maximum speed.

To improve the mileage of the electric vehicle (EV), the EV motors are designed for higher power density and higher efficiency. Maximum slot occupation (MSO coil) developed to improve the power density of motors have fill factor up to 80%. MSO coil with large fill factor has large conductor cross-sections. These conductors occur additional losses due to the AC resistance. This paper presents a design method for the higher efficiency of the motor using the MSO coil. The shapes of the slots and the coils are determined to satisfy the output and minimize the resistance loss by checking the tendency of the output and the resistance loss according to the shape of the slot and the coil. Finally, to verify the validity of the design method, the vehicle simulation will be performed using advanced vehicle simulator (ADVISOR).

This paper proposes a design method for a high speed response motor system consisting of a motor and load. Various methods have been studied to improve the speed response of the motor system, but the main focus was previously advanced control techniques. However, the dynamic response of the controller can be further improved when the dynamic response of the plant improves. The proposed method improves the speed response by increasing the bandwidth of the motor system which is the plant of the servo system. Thus, the relationship between the bandwidth and speed response has been investigated. As the both electrical and mechanical parameters affect the speed response and bandwidth of the motor system, the correlation of the time constants and bandwidth were analyzed. Based on the analyzed results, the process of designing a motor system with maximized bandwidth was introduced. Therefore, a motor system with maximized bandwidth was designed using the proposed design process. Finally, the rated power and speed response of the motor system were verified through simulations.

This paper proposes a design guideline for selecting the pole and slot combination of an outer-rotor permanent magnet synchronous motor (PMSM) using a maximum slot occupation (MSO) coil. Because the MSO coil has a large conductor area, the AC Joule loss in the conductors may be increased at high frequencies. To ensure high-efficiency for the PMSM, it is necessary to reduce the loss. Thus, it is important to select the pole- and slot- combination that has the minimum AC Joule loss. The loss is caused by skin/proximity effects and variations in the slot leakage flux. The skin effect is due to the armature winding and the variation in the slot leakage flux is due to the field flux. A method for separating the AC Joule loss due to each component using the frozen permeability method is proposed. Based on the proposed method, the effect of each cause on the loss at various pole- and slot- combinations is analyzed in this study.

The tungsten (W) brazed flat type mock-up which consists of W, OFHC-Cu (oxygen-free high conductive copper) and CuCrZr alloy has been designed for KSTAR divertor in preparation for KSTAR upgrade with 17 MW heating power. For verification of the W brazed mock-up, the high heat flux test is performed at KoHLT-EB (Korea High Heat Load Test Facility-Electron Beam) in KAERI (Korea Atomic Energy Research Institute). Three mock-ups are tested for several thousand thermal cycles with absorbed heat flux up to 5 MW/m 2 for 20 s duration. There is no evidence of the failure at the bonding joints of all mock-ups after HHF test. Finite element analysis (FEA) is performed to interpret the result of the test. As a result, it is considered that the local area in the water is in the subcooled boiling regime.

Background Acute myocardial infarction (AMI) is a risk factor for contrast-induced nephropathy (CIN). We investigated whether pretreatment with statin, N-acetylcysteine (NAC) and sodium bicarbonate (NaHCO 3 ) reduces the risk of CIN. Methods We conducted a prospective trial and enrolled a total of 334 ST-segment elevation myocardial infarction (STEMI) patients. Patients were divided into four groups: Group I (statin 40mg), Group II (statin 80mg), Group III (statin 80mg plus NAC 1200mg) and Group IV (regimen of group III plus NaHCO 3 154mEq/L). CIN was defined as ≥25% or ≥0.5mg/dL increase in serum creatinine from the baseline within the 72h after PCI. Results CIN occurred in 72 (21.6%) patients. The incidence of CIN was the lowest in the group III (14.3%), and multivariate analysis showed the lower incidence of CIN in group III compared to Group I [odds ratio (OR) 0.29, 95% confidence interval (CI) 0.13–0.64, p=0.002]. Admission hyperglycemia [(AHG)>198mg/dL] (OR 2.20, 95% Cl 1.20–3.68, p=0.011) and the use of intra-aortic balloon pump (IABP) (OR 4.20, 95% CI 1.38–12.78, p=0.016) were independent predictors for CIN. The CIN (OR 9.00, 95% CI 1.30–62.06, p=0.026) was an independent predictor for in-hospital mortality. Conclusions Combination of high-dose statin plus NAC was associated with lower incidence of CIN in patients with STEMI who underwent primary PCI compared to statin only.

Objectives To determine the molecular events related to penile erection in the corpus cavernosum tissue of mice after electrical stimulation of the cavernous nerve. Methods Twelve-week-old male C57BL/6 mice were used in this study. Electrical stimulation of the cavernous nerve was carried out to induce penile erection. Corpus cavernosum tissues were then harvested to determine the effect of nerve-induced penile erection on signaling pathway involved in angiogenesis (vascular endothelial growth factor, hepatocyte growth factor, angiopoietin-1, matrix metalloproteinase 2, and matrix metalloproteinase 9), cell survival and proliferation (phosphatidylinositol 3-kinase, phospho-Akt/Akt, and phospho-ERK/ERK), and tissue fibrosis (phospho-Smad2/Smad2, phospho-Smad3/Smad3, and plasminogen activator inhibitor-1). Results Cavernous nerve stimulation enhanced the expression of factors involved in angiogenesis (vascular endothelial growth factor, hepatocyte growth factor, angiopoietin-1, matrix metalloproteinase 2, and metalloproteinase 9), and activated intracellular signaling mediators related to cell survival and proliferation (phosphatidylinositol 3-kinase, phospho-Akt/Akt, and phospho-ERK/ERK), while suppressing the pathways involved in tissue fibrosis (phospho-Smad2/Smad2, phospho-Smad3/Smad3, and plasminogen activator inhibitor-1). Conclusions Penile erection in mice is accompanied by the activation of a cascade of signaling pathways involved in angiogenesis, cell survival and proliferation, and antifibrosis. The present results might provide a theoretical and molecular basis for understanding the importance of penile rehabilitation and subsequent restoration of nocturnal or sexually-mediated penile erections.