NPC-IGCT Phase Module Clamp Circuit LRC Parameters Design considering FRD snappy Recovery

Yang Ju Zou,Jia Xi Hu,Zhen Yu Ma,Jian Ping Liu,Run Qing Guo,Zhi Xue Zhang 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

In this paper, a method for neutral point clamping-integrated gate commutated thyristor (NPCIGCT) phase module clamp circuit parameters design considering FRD snappy recovery is present. Based on the snappy recovery theory, and analysis of snappy recovery factors, the paper has shown decreasing current commutating slope can attenuated snappy recovery affect effectively. Then, the paper has shown that it is reasonable for decreasing di/dt by increasing inductance of NPC-IGCT phase module clamp circuit, based on the circuit working principle. Then, the new clamp circuit parameters design method which combine multi-objective optimization solution mathematical module of the circuit, fast recovery diode (FRD) snappy recovery, devices overvoltage and loss is shown in paper. A design example and its test results have demonstrated both IGCT and FRD characteristics have been guaranteed and ensuring safety and reliability of the NPC - IGCT phase module.

Encoding of direct 4D printing of isotropic single-material system for double-curvature and multimodal morphing

Bihui Zou,Chao Song,Zipeng He,Jaehyung Ju 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

The ability to morph flat sheets into complex 3D shapes is extremely useful for fast manufacturing and saving materials while also allowing volumetrically efficient storage and shipment and a functional use. Direct 4D printing is a compelling method to morph complex 3D shapes out of as-printed 2D plates. However, most direct 4D printing methods require multi-material systems involving costly machines. Moreover, most works have used an open-cell design for shape-shifting by encoding a collection of 1D rib deformations, which cannot remain structurally stable. Here, we demonstrate the direct 4D printing of an isotropic single-material system to morph 2D continuous bilayer plates into doubly curved and multimodal 3D complex shapes whose geometry can also be locked after deployment. We develop an inverse-design algorithm that integrates extrusion-based 3D printing of a single-material system to directly morph a raw printed sheet into complex 3D geometries such as a doubly curved surface with shape locking. Furthermore, our inverse-design tool encodes the localized shape-memory anisotropy during the process, providing the processing conditions for a target 3D morphed geometry. Our approach could be used for conventional extrusion-based 3D printing for various applications including biomedical devices, deployable structures, smart textiles, and pop-up Kirigami structures.

Encoding of direct 4D printing of isotropic single-material system for double-curvature and multimodal morphing

Bihui Zou,Chao Song,Zipeng He,Jaehyung Ju 대한기계학회 2022 대한기계학회 춘추학술대회 Vol.2022 No.11

The ability to morph flat sheets into complex 3D shapes is extremely useful for fast manufacturing and saving materials while also allowing volumetrically efficient storage and shipment and a functional use. Direct 4D printing is a compelling method to morph complex 3D shapes out of as-printed 2D plates. However, most direct 4D printing methods require multi-material systems involving costly machines. Moreover, most works have used an open-cell design for shape-shifting by encoding a collection of 1D rib deformations, which cannot remain structurally stable. Here, we demonstrate the direct 4D printing of an isotropic single-material system to morph 2D continuous bilayer plates into doubly curved and multimodal 3D complex shapes whose geometry can also be locked after deployment. We develop an inverse-design algorithm that integrates extrusion-based 3D printing of a single-material system to directly morph a raw printed sheet into complex 3D geometries such as a doubly curved surface with shape locking. Furthermore, our inverse-design tool encodes the localized shape-memory anisotropy during the process, providing the processing conditions for a target 3D morphed geometry. Our approach could be used for conventional extrusion-based 3D printing for various applications including biomedical devices, deployable structures, smart textiles, and pop-up Kirigami structures.

Fermentation Optimization and Industrialization of Recombinant Saccharopolyspora erythraea Strains for Improved Erythromycin A Production

Xiang Zou,Chang-fa Chen,Xia-chang Qi,Jiang-chao Qian,Ju Chu,Ying-ping Zhuang,Si-liang Zhang,Wei Zeng,Wan-jun Li 한국생물공학회 2010 Biotechnology and Bioprocess Engineering Vol.15 No.6

Improvement of Erythromycin A (Er-A) production and purity by metabolic engineering of the industrial erythromycin-producing strains Saccharopolyspora erythraea strians ZL1004 and ZL1007, in which the amounts of tailoring enzymes EryK (a P450 hydroxylase)and EryG (an S-adenosylmethionine-dependent O-methyltransferase)for biotransformation of Erythromycin D to Er-A were modulated, was performed in a 50 L fermentor. Addition of 15 g/L of corn steep liquor to the medium increased Er-A production; maximum Er-A production was 8,196 U/mL at 191 h, which was 81.8% higher than that of control (4,507 U/mL at 184 h). Er-B impurities were completely eliminated, whereas Er-C impurities were only 153 U/mL at 191 h. Analysis of intra- and extracellular metabolites and key enzyme activities in central carbon metabolism revealed that the pool of TCA cycle intermediates was enhanced by the addition of corn steep liquor and induced an increase in erythromycin biosynthesis. There were no significant differences between strains ZL1004 and ZL1007 regarding Er-A production and impurity accumulation. Compared to wild type strain,Er-A production was improved by 23.9% while Er-C was reduced by 83.9% and Er-B was completely eliminated. Furthermore, fermentation of recombinant strain ZL1004was successfully scaled up from laboratory scale (50 L fermentor) to industrial scale (25 and 132 m3), with similar levels of Er-A production and purity obtained.

High-Efficient Evaluation of the Lightning Electromagnetic Radiation Over a Horizontally Multilayered Conducting Ground With a New Complex Integration Path

Jun Zou,Boyuan Zhang,Xuelong Du,Jaebok Lee,Munno Ju IEEE 2014 IEEE transactions on electromagnetic compatibility Vol.56 No.3

<P>An efficient approach to evaluate the radiated electromagnetic field of a lightning channel over a horizontally stratified conducting ground is proposed in this paper. The electromagnetic field component produced by a lightning channel, expressed in the form of generalized Sommerfeld integral (GSI) with a complicated integrand, is calculated along a newly proposed path in the complex plane. Due to the change of the integration path, the integrand in the GSI turns out to decay dramatically fast and without any oscillation at all. As explained in this paper, the larger horizontal distance will become the benefit to achieve a quicker convergence, which is just opposite to the case that the integration path is along the real axis. The validity of the proposed methodology is justified by the extensive comparison with the results in other publications. As a matter of fact, the methodology in this paper can be generalized to evaluate stratified conducting ground with any number of layers.</P>

Src-like adaptor protein regulates osteoclast generation and survival

Kim, Hyun-Ju,Zou, Wei,Ito, Yuji,Kim, Shin-Yoon,Chappel, Jean,Ross, F. Patrick,Teitelbaum, Steven L. Wiley Subscription Services, Inc., A Wiley Company 2010 Journal of cellular biochemistry Vol.110 No.1

<P>Src-like adaptor protein (SLAP) is a hematopoietic adaptor containing Src homology (SH)3 and SH2 motifs and a unique carboxy terminus. Unlike c-Src, SLAP lacks a tyrosine kinase domain. We investigated the role of SLAP in osteoclast development and resorptive function. Employing SLAP-deficient mice, we find lack of the adaptor enhances in vitro proliferation of osteoclast precursors in the form of bone marrow macrophages (BMMs), without altering their survival. Furthermore, osteoclastogenic markers appear more rapidly in SLAP−/− BMMs exposed to RANK ligand (RANKL). The accelerated proliferation of M-CSF-treated, SLAP-deficient precursors is associated with enhanced ERK activation. SLAP's role as a mediator of M-CSF signaling, in osteoclastic cells, is buttressed by complexing of the adaptor protein and c-Fms in lipid rafts. Unlike c-Src, SLAP does not impact resorptive function of mature osteoclasts but induces their early apoptosis. Thus, SLAP negatively regulates differentiation of osteoclasts and proliferation of their precursors. Conversely, SLAP decreases osteoclast death by inhibiting activation of caspase 3. These counterbalancing events yield indistinguishable bones of WT and SLAP−/− mice which contain equal numbers of osteoclasts in basal and stimulated conditions. J. Cell. Biochem. 110: 201–209, 2010. © 2010 Wiley-Liss, Inc.</P>

ER81-shRNA Inhibits Growth of Triple-negative Human Breast Cancer Cell Line MDA-MB-231 In Vivo and in Vitro

Chen, Yue,Zou, Hong,Yang, Li-Ying,Li, Yuan,Wang, Li,Hao, Yan,Yang, Ju-Lun Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.5

The lack of effective treatment targets for triple-negative breast cancers make them unfitted for endocrine or HER2 targeted therapy, and their prognosis is poor. Transcription factor ER81, a downstream gene of the HER2, is highly expressed in breast cancer lines, breast atypical hyperplasia and primary breast cancers including triple-negative examples. However, whether and how ER81 affects breast cancer carcinogenesis have remained elusive. We here assessed influence on a triple-negative cell line. ER81-shRNA was employed to silence ER81 expression in the MDA-MB-231 cell line, and MTT, colony-forming assays, and flow cytometry were used to detect cell proliferation, colony-forming capability, cell cycle distribution, and cell apoptosis in vitro. MDA-MB-231 cells stably transfected with ER81-shRNA were inoculated into nude mice, and growth inhibition of the cells was observed in vivo. We found that ER81 mRNA and protein expression in MDA-MB-231 cells was noticeably reduced by ER81-shRNA, and that cell proliferation and clonality were decreased significantly. ER81-shRNA further increased cell apoptosis and the residence time in $G_0/G_1$ phase, while delaying tumor-formation and growth rate in nude mice. It is concluded that ER81 may play an important role in the progression of breast cancer and may be a potentially valuable target for therapy, especially for triple negative breast cancer.

Chronic effects of ketamine on gene expression changes in neurotransmitter receptors and regulators-A PCR-array study

Sijie Tan,Ju Zou,Meixiang Li,David T Yew,S. Tan 대한독성 유전단백체 학회 2015 Molecular & cellular toxicology Vol.11 No.4

Abuse of ketamine increased rapidly and chronic use of ketamine may result in dependence. We investigated the long-term effects of ketamine on anxiety like behaviors and gene expression changes in neurotransmitter receptors and regulators in mice. One month old ICR mice received sub-anesthetics dose of ketamine daily for 3 months. An Elevated Plus Maze (EPM) was employed to assess anxiety like behaviors in these mice and a PCR Array was used to evaluate gene expression changes in neurotransmitter receptors and regulators in the brain. Ketamine decreased the time spent in the open arms and the visit of the open arms in the EPM. Drug dependence related genes, namely Prokr2, Npffr1 and GalR2 were differentially expressed in ketamine treated mice. The results of the present study depicted addictive potential of ketamine and may be beneficial for developing pharmacotherapies for ketamine dependence.

한국어 학습자의 읽기 전략 연구 - 한·중 대학의 학부생 비교를 중심으로 -

이주미 ( Lee Ju-mi ),노정은 ( Noh Jung-eun ),( Zou Ai-fang ) 국제어문학회 2015 국제어문 Vol.0 No.64

본고는 학문 목적 한국어 학습자와 한국어 모어 화자인 한국 대학생들을 대상으로 하여 학습자들이 사용하는 읽기 전략에 대해 비교 분석하여 그 차이를 살펴보고자 하였다. 이에 한국인 모어 화자와 중국 소재의 한국어 학부생들을 대상으로 읽기를 수행할 때 어떤 전략을 주로 사용하며 어떤 전략을 잘 사용하지 못하는지에 대해 밝혔다. 이를 통해 읽기 전략 양상을 비교하고 그 차이를 밝혀 전략 교육을 할 때 어떤 단계에서 어떠한 전략을 가르치는 것이 가능한지 시사점을 도출해 내고자 하였다. 읽기 전략의 사용은 크게 두 부분으로 나누어 살펴보았는데 정보처리의 관점에 따른 읽기 전략 사용과 읽기 과정 중에서의 전략 사용이 어떻게 이루어지고 있는지를 살펴보았다. 연구 결과 정보처리 관점에서 두 집단은 상향식 전략, 하향식 전략, 초인지 전략에서 자주 사용하는 전략이 다른 것으로 나타났다. 먼저 한국어 모어 화자는 전체적으로 읽기 전략을 한국어 학습자보다 더 많이 사용하고 있었으며 하향식과 초인지 전략을 많이 사용하고 있는 반면 한국어 학습자들은 상향식 전략의 사용이 많았다. 범주별 전략에서도 하향식과 초인지 전략에서 차이가 나타났는데, 특히 초인지 전략에서의 차이가 더욱 두드러지게 나타났다. 읽기 전, 중, 후 과정에서는 특히 읽기 중과 읽기 후의 전략에서는 확연한 차이를 보였다. 한국인 모어 화자와 한국어 학습자의 전략 사용 양상의 차이는 학문 목적 상황에서 한국어 학습자에게 중점적으로 교육해야 하는 전략과 읽는 과정 중에 적용해야 하는 전략이 무엇인지 방향을 제시할 수 있다는 점에서 의의가 있다. 읽기 전략에 대한 내용은 명시적(explicit)으로 교수되어야 하며 학습자들에게 읽기 전략에 대한 내용과 방법을 충분히 안내해 주어야 할 것이다. The purpose of this study was to compare the aspect of strategic reading performance between Korean native speakers and Chinese undergraduate students who are learning Korean in China. Also this study provides the framework of basic research on strategic education that compares the aspects of reading strategies and investigates its differences. The finding showed that frequently used strategy were different between two groups and the different strategies varied from bottom-up strategies, top-down strategies, metacognitive strategies and support strategies. First, Korean native speakers use strategic reading more than Korean language learners and also the natives tend to use more top-down and metacognitive strategies while the other use more bottom-up strategies. As for strategy category, there were differences between top-down and metacognitive strategy and it was found that there was more significant difference especially in metaconitive strategies. There were insignificant differences between Korean language learners and Korean native speakers before reading in the pre-, while- and post-reading process but definite differences in while- and post-reading strategies. The significant difference of strategy choice between Korean native speakers and Korean language learners can suggest the strategic direction that can be applied during reading process and to educate strategies in priority. The contents about reading strategies should be taught explicitly and the learners should be thoroughly informed about reading strategies` contents and method.

Ground Admittance of an Underground Insulated Conductor and its Characteristic in Lightning Induced Disturbance Problems

Zhang, Boyuan,Zou, Jun,Du, Xuelong,Lee, Jaebok,Ju, Mun-No IEEE 2017 IEEE transactions on electromagnetic compatibility Vol.59 No.3

<P>The evaluation of the ground admittance of an underground insulated conductor with a homogeneous nonmagnetic earth is of great significance when the electromagnetic compatibility is concerned. To evaluate the ground admittance efficiently, researchers proposed that the ground impedance of the conductor should be evaluated first and the ground admittance is related to the ground impedance through the wave number in the soil. There are several approximated analytical expressions for the evaluation of the ground impedance with a homogeneous earth and this fact makes the ground admittance easy to obtain. The characteristic of the approximated ground admittance evaluation approach is examined in this paper. Numerical examples illustrate that at frequencies with which the burial depth is much larger than the skin depth in the soil, the ground admittance and the ground impedance of the buried cable are well-related through the wave number in the soil. However, at other frequencies, the approximated approach fails to evaluate the ground admittance accurately. This paper also reveals that the discrepancy of the ground admittance will lead to a noticeable difference in the lightning induced voltage on buried cables.</P>