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Objective Premature ovarian insufficiency (POI) is a clinical disease that is diagnosed by the loss of ovarian function before the age of 40. Despite recent progress in molecular diagnosis, the genetic etiology of POI is not well established. The aim of this study is to reveal pathogenic genetic variants involved in POI. Study design and main outcome measures To reveal pathogenic genetic variants involved in POI, whole exome sequencing was performed in nonconsanguineous family members with POI. Constitutional variants were filtered against population databases and a missense mutation of natriuretic peptide C (NPPC) (c.131A>G, p.Q44R) was selected as a convincing candidate mutation among 14 heterozygous mutant alleles in 13 genes. Results The wild-type NPPC and mutant NPPC (NPPC131A>G) were expressed in HeLa cells, and cells expressing NPPC131A>G secreted unique peptides. The ProP 1.0 Server, a neural network prediction tool, predicted the presence of a cleavage site at the substituted arginine residue (p.Q44R) of NPPC. The molecular weight of predicted cleaved peptides processed from mutant NPPC precursor corresponded to that of the actual mutant peptide. The cGMP synthetic activity of NPR2-expressing cells was significantly decreased by interaction with the mutant NPPC peptide compared with wild-type NPPC. Conclusions The peptide generated by a rare mutation of NPPC might influence paracrine C-type natriuretic peptide (CNP)-mediated preantral follicle development and/or sustain meiotic arrest in oocytes. We therefore suggest that a mutation of the NPPC gene is involved in the pathogenesis of POI.

Objective Dystrophinopathy is an X-linked recessive muscular dystrophy caused by mutations in the DMD gene. Herein we describe the prenatal detection of DMD gene mutations in a patient with no family history, by multiplex ligation-dependent probe amplification (MLPA) after noninvasive prenatal screening (NIPS). Case report A 41-year-old woman underwent NIPS owing to an advanced maternal age. A copy number variation was detected in the maternal X chromosome, and uninformative results were obtained for the fetal sex chromosomes. Following amniocentesis, a duplication was identified in exons 1–29 of the dystrophin gene by MLPA. After interviewing her family members it was confirmed that the patient is a de novo carrier of DMD duplications, and her daughter is a carrier of the same mutation. Conclusion his is the first case report to describe the prenatal diagnosis of duplications in the DMD gene by MLPA following NIPS in a patient with no family history.

The risk of chromosomal abnormalities in the child increases with increasing maternal age. Although non-invasive prenatal testing (NIPT) is a safe and effective prenatal screening method, the accuracy of the test results needs to be improved owing to various testing conditions. We attempted to achieve a more accurate and robust prediction of chromosomal abnormalities by combining multiple methods. Here, three different methods, namely standard Z-score, normalized chromosome value, and within-sample reference bin, were used for 1698 reference and 109 test samples of whole-genome sequencing. The logistic regression model combining the three methods achieved a higher accuracy than any single method. In conclusion, the proposed method offers a promising approach for increasing the reliability of NIPT.

The stromal antigen 3 (STAG3) gene, encoding a meiosis-specific cohesin component, is a strong candidate for causing male infertility, but little is known about this gene so far. We identified STAG3 in patients with nonobstructive azoospermia (NOA) and normozoospermia in the Korean population. The coding regions and their intron boundaries of STAG3 were identified in 120 Korean men with spermatogenic impairments and 245 normal controls by using direct sequencing and haplotype analysis. A total of 30 sequence variations were identified in this study. Of the total, seven were exonic variants, 18 were intronic variants, one was in the 5'-UTR, and four were in the 3'-UTR. Pathogenic variations that directly caused NOA were not identified. However, two variants, c.3669+35C>G (rs1727130) and +198A>T (rs1052482), showed significant differences in the frequency between the patient and control groups (P = 0.021, odds ratio [OR]: 1.79, 95% confidence interval [CI]: 1.098-2.918) and were tightly linked in the linkage disequilibrium (LD) block. When pmir-rs1052482A was cotransfected with miR-3162-5p, there was a substantial decrease in luciferase activity, compared with pmir-rs1052482T. This result suggests that rs1052482 was located within a binding site of miR-3162-5p in the STAG3 3'-UTR, and the minor allele, the rs1052482T polymorphism, might offset inhibition by miR-3162-5p. We are the first to identify a total of 30 single-nucleotide variations (SNVs) of STAG3 gene in the Korean population. We found that two SNVs (rs1727130 and rs1052482) located in the 3'-UTR region may be associated with the NOA phenotype. Our findings contribute to understanding male infertility with spermatogenic impairment.

There is an extensive research literature on the effects of the Supplemental Nutrition Assistance Program (SNAP) on food‐related outcomes which has shown somewhat mixed results but generally favorable effects. However, most of the research has used data sets whose information on SNAP participation is gathered from responses on household surveys, and such responses are subject to reporting error. This study uses the National Household Food Acquisition and Purchase Survey data set to examine the effect of reporting error on food‐related outcomes, for that data set contains information on SNAP participation gathered from government administrative records. Our analysis shows that the degree of reporting error is small and has little effect on the estimated impact of participation in the SNAP program on food security, diet quality, and food spending. A supplemental analysis of the effect of school food programs likewise shows no difference in using survey or administrative data in the analysis.

The exponential data size growth in high-speed networks is a key motivator for nonvolatile memory development. To support this demand, higher density NAND is required: with a smaller cell size and higher interface speed. Generally, scaling down NAND technology requires addressing several common issues: 1) As the number of WL stack layers increases, the cell-string current is reduced due to the increased resistance in a cell string, 2) Deterioration of cell-to-cell interference, due to the reduction of cell pitch, 3) Support of higher IO bandwidth for faster data transfer speed [1]. Another challenge of this work was to minimize the die size because the peripheral circuit area is comparable to that of the cell array. Hence, we integrated the peripheral circuits below the cell array as introduced in [2]. Also, to cope with lower metal-contact height, a novel structure for the capacitor device was used to maximize capacitance per unit area.

While studies on embryonic stem cells have been actively conducted, little is known about the epigenetic mechanisms in human embryonic stem cells (hESCs) in extended culture systems. Here, we investigated whether CpG island (CGI) methylation patterns of 24 tumor suppressor genes could be maintained during extended hESC cultures. In total, 10 hESC lines were analyzed. For each cell line, genomic DNA was extracted from early and late passages of cell cultures. CGI methylation levels of 24 tumor suppressor genes were analyzed using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA), pyrosequencing, and real-time polymerase chain reaction (PCR). Different CGI methylation patterns of CASP8, FHIT, and CHFR genes were identified in between early and late passages in some hESC lines. CGI methylation levels of CASP8 significantly increased at late passage in CHA-36, CHA-40, and CHA-42 cell lines compared to those at early passage. The CGI methylation of the FHIT gene was higher at late passage than at early passage in CHA-15, CHA-31, CHA-32, and iPS (FS)-1 cell lines but decreased at the late passage in CHA-20 and H1 cell lines. Different CGI methylation patterns were detected for the CHFR gene only in iPS (FS)-1, and the level significantly increased at late passage. Thus, our findings show that CGI methylation patterns could be altered during prolonged ESC cultures and examining these epigenetic changes is important to assess the maintenance, differentiation, and clinical usage of stem cells.

This paper proposes an energy management system (EMS) of direct current (DC) microgrid. In order to implement the proposed EMS, the control and operation method of EMS is presented in this work. While most of the studies have individually examined the grid-connected mode used in building and the stand-alone operation mode applicable to the island, the proposed EMS allows it to be used in both grid-connected mode and stand-alone mode with 10 modes. In order to determine each mode in EMS, not only the amount of generated power, load power, and the state of charge (SOC) of the battery, but also the rated power of the energy storage system (ESS) converter that performs charging and discharging operations is additionally considered. Thus, various uncertainties that may occur in the actual DC microgrid environment can be improved. A laboratory-scale DC microgrid is fabricated to conduct experimental validation of proposed EMS. Experiments of DC microgrid with proposed EMS were performed for each mode, and the experiment waveforms of each power conversion device are included in detail.

This paper proposes a new three-dimension (3-D) space vector pulse width modulation (SVPWM) for three-phase four-wire inverter under line-to-line (L-L) fault. To perform this method, we discussed coordinate transformation matrix to rotate the distorted voltage vector plane into a new coordinate system under L-L fault. In addition, this paper presented the selection of the output voltage vectors and mathematically analyzed the synthesis of the reference vector and calculation of the duty cycles. Through the above process, even though L-L fault occurs in distribution network, zero voltage can be supplied to the point of failure, and voltage can be supplied normally to the rest of the phases. The simulations and experimental results are provided to validate the effectiveness of the proposed method.

In this paper, increase in distributed power sources such as renewable energy sources, is increasing interest in microgrid that supply power by distributing. Research on various distribution network operation methods has been conducted. we adopted LabVIEW to design an interactive monitoring interface for EMS (Energy Monitoring System) operation of AC / DC hybrid microgrid. The provided monitoring interface works in conjunction with the reduced AC / DC microgrid experiment environment, allows operator to observe the impact on the system by input the change to the distribution system in addition to reading data from the distribution network. It will also be useful for testing various operational methods of microgrid system.

Active damping method and load current feedforward control method has been studied for control dc bus voltage in DC microgrid. Since load current feedforward control method requires information through communication, performance of controller is affected by communication time delay. This paper analyzes time delay performance of DC bus voltage variation with four control strategies based on the two control methods. DC bus voltage variation with four control strategies are simulated and analyzed considering three time delay cases.

A study on parallel operation has been conducted in the previous study on battery pack charging/ discharging system, but few studies have been made on serial connection. Due to the characteristics of the battery charging and discharging application in series, the master module controls the battery current, and the slave module controls the output voltage of each module. However, this control method causes unbalance of the output voltage of each converter module, which may cause deterioration and damage of some converter modules. Therefore, in this paper, we proposed a series control method of 3-Phase CurrentFed Dual Active Bridge (3P-CFDAB) Converter that can solve the output voltage unbalance between modules during series operation. The proposed control technique was verified through PowerSIM simulation and experiment

This paper proposes an artificial neural network (ANN)-based energy management system (EMS) for controlling power in AC–DC hybrid distribution networks. The proposed ANN-based EMS selects an optimal operating mode by collecting data such as the power provided by distributed generation (DG), the load demand, and state of charge (SOC). For training the ANN, profile data on the charging and discharging amount of ESS for various distribution network power situations were prepared, and the ANN was trained with an error rate within 10%. The proposed EMS controls each power converter in the optimal operation mode through the already trained ANN in the grid-connected mode. For the experimental verification of the proposed EMS, a small-scale hybrid AD/DC microgrid was fabricated, and simulations and experiments were performed for each operation mode.

A 48 WL stacked 256-Gb V-NAND flash memory with a 3 b MLC technology is presented. Several vertical scale-down effects such as deteriorated WL loading and variations are discussed. To enhance performance, reverse read scheme and variable-pulse scheme are presented to cope with nonuniform WL characteristics. For improved performance, dual state machine architecture is proposed to achieve optimal timing for BL and WL, respectively. Also, to maintain robust IO driver strength against PVT variations, an embedded ZQ calibration technique with temperature compensation is introduced. The chip, fabricated in a third generation of V-NAND technology, achieved a density of 2.6 Gb/mm2 with 53.2 MB/s of program throughput.

This paper proposes energy management system (EMS) for power control in low voltage direct current (LVDC) distribution system. Since LVDC distribution system is connected to various distributed generators and power conversion devices, each situation of generated and load power should be considered for stable operation. Power control of LVDC distribution system must be required for its reliability and can be implemented by operation and control strategy of EMS. In this paper, proposed EMS defines each operation mode considering various conditions and each converter is controlled by centralized control based control strategy of EMS. Feasibility and stability of proposed EMS is verified by experiment results of LVDC distribution system including distributed energy resource such as wind turbine, photovoltaic array, battery and DC/AC load.

This paper proposes a selective control algorithm to reduce switching losses of N-phase switching pole of 3-phase 4-leg interlinking converter (ILC) in AC/DC hybrid microgrid. Unbalanced load connected to 3-phase 4-leg ILC causes unbalanced voltage condition and this problems can be complemented by N-phase switching pole of 4-leg ILC. However, if the switching pole on N is operated constantly regardless of control decision due to unbalanced load conditions, switching loss on the N-phase switching pole will cause power loss in the entire topology. To compensate this problem, selective control algorithm considering voltage unbalance factor (VUF) for N-phase switching pole in ILC is proposed. Proposed algorithm decides switching operation of N-phase switching pole depending on unbalanced load voltage. When occurring unbalanced load condition, voltage unbalance factor can be reduced by proposed control algorithm. At the same time, the current flowing through the N-phase switch pole and switching losses can be reduced.

To convert the three-phase AC power to DC power, conventional power conversion system has a 2-stage configuration which consists of the AC/DC PFC and isolated DC/DC converter system. However, this configuration has the disadvantage that the volume of the system increases and the efficiency decreases due to two-times of the power conversion process. Therefore, in this paper, we propose a three-phase bridgeless PFC system with LLC resonant circuit for improvement of power factor, input current THD and efficiency through soft switching.

Cascaded NPC (Neutral Point Clamped)/H-bridge (CNHB) inverter is one of Multi-level inverters, and widely used for a large-capacity industrial motor driving. When a fault occurs in the power modules in CNHB, the neutral point shifting control which is commonly used for fault-tolerance control has a disadvantage that power imbalance is occurred between the power modules even though it can operate continuously in case of failure. This paper proposed advanced fault-tolerance control to achieve power equalization of power modules in case of malfunction. The proposed control method is select the limit value of the maximum reference voltage for neutral point voltage shifting control so that root mean square (RMS) values of the output phase voltage of each module are equal and power imbalance is reduced. Power characteristics with proposed control method are analyzed mathematically. Proposed control method is verified by simulation based on 10[kW] scale of CNHB.

In this paper, a modified droop control method is proposed to minimize variation of common bus voltage. The proposed control method models line impedance between load and auxiliary power supply to compensate for voltage drop of power line. The expected voltage drop of the modelled line impedance is mathematically analyzed and applied to the traditional droop curve to design the modified drop equation. The controller has a cascaded structure with inner current and voltage control loops and outer power control loop. A droop curve for power control is applied a modified droop equation to reduce the load voltage drop due to the line impedance. The validity of a modified droop control is verified using two 85kVA auxiliary power supply units connected in parallel.

Data storage is one of the hottest discussion topics in today’s connected world. The amount of data growth is expected to be exponential, while budget and space remain constricted. Since the transformation of storage device from planar NAND to 3D V-NAND [1], the areal density of semiconductor storage devices has continuously evolved and has surpassed the density of magnetic hard drives. By providing the largest storage capacity in the smallest footprint, 3D V-NAND has been leading the data center revolution in recent years. However, 3D-technology scaling faces several technical challenges [2]. (1) As the number of WL stacks increases the channel-hole etch process becomes a limit, since the total WL-mold height increases. (2) Interference between cells increases since the distance between WLs becomes smaller. (3) Faster data transfer speeds are required to support higher IO bandwidth.