자기진단형 위상제어에 의한 단상유도전동기의 특성 및 모니터링 시스템에 관한 연구

조금배,박수강,백형래,임양수,이성길 조선대학교 에너지.자원신기술연구소 2003 에너지·자원신기술연구소 논문지 Vol.25 No.2

The three-phase induction motor is rugged, reliable, long-lived, self-starting, smooth-running. But it is relatively inexpensive and three-phase power in not available everywhere, so if possible we need single-phase motor with the same characteristics. In fact, single-phase induction motors have excellent characteristics and outnumber the three-phase variety. Most of the small electric motors used in home, farm, or office are single-phase induction motors of one type or another. This electric motors application field need most energy saving type drive according to enlargement of electronic goods and to tend high class. The paper is proposed a various phase control methods for energy saving of single- phase induction motor. The controllers that are embodied by each method can use by various usage according to each performance and it is considered that application may help in the electrical energy saving because is possible to other electrical appliances.

폐경기 여성에서의 Cyclofenil의 효능에 관한 연구 : 갱년기 장애 및 Ca 장흡수에 관하여

노흥규,윤상임,성기양,이경숙,이강욱 충남대학교 의과대학 지역사회의학연구소 1991 충남의대잡지 Vol.18 No.1

In postmenopausal syndrome, most common symptoms are those of vasomotor irritability such as hot flush and palpitation, irritable bladder symptoms and dyspareunia according to atrophy of urogenital epithelium, anxiety, nervousness, depression and insomnia. Approximately 40 percent of women in postmenopausal period develop symptoms serious enough to seek medical assistance. Among non-steroid agents, cyclofenil(4, 4' cyclohexidene methlyene diphenoacetate) is known to be a quite interesting substance according to the action at the level of the hypophyseal and hypothalamic centers by reducing the incretion of FSH and restoring normal endorphin, dopamine and norepinephrine activities, thus favorably affecting the whole postmenpausal neurovegutative symptomatology. In order to evaluate effect of cyclofenil on postmenopausal symptomatology and calcium metabolism, we examined 32 patients with postmenopausal syndrome before and after 200mg/day of oral cyclofenil treatment for 30-60 days. The results were as follows: 1. With 30 days of cyclofenil administration, subjective symptoms such as facial flush, palpitation, anxiety, nervousness and dyspareunia were improved significantly (p<0.001, p<0.001, p<0.01, p<0.005, respectively). But insomnia and depression were improved significantly after 60 days of cyclofenil administration (p<0.05, p<0.001, respectively). 2. Intestinal calcium absorption rate disclosed tendency of improvement without statistical significance 30 days after cyclofenil treatment. 3. Serum calcium and phosphorus level were not changed significantly before and after cyclofenil. 4. There was no definite evidence of side effects such as uterine bleeding due to cyclofenil. In conclusion, we thought that cycofenil is effective in management of postmenopausal syndrome but for the effect on calcium metabolism, further evaluation should be needed.

Brewing Rutin-Enriched Lager Beer with Buckwheat Malt as Adjuncts

( Yang Deng ),( Juho Lim ),( Gang-hee Lee ),( Thi Thanh Hanh Nguyen ),( Yang Xiao ),( Meizi Piao ),( Doman Kim ) 한국미생물생명공학회(구 한국산업미생물학회) 2019 Journal of microbiology and biotechnology Vol.29 No.6

Brewing with buckwheat as an ingredient has been proven to be successful in several previous studies. However, few studies have focused on the effects of buckwheat on the rutin content and antioxidant activity of beer. In order to develop a lager beer with high rutin content and desirable sensory characteristics, tartary buckwheat malt was used as a brewing adjunct. The results showed that the rutin-degrading enzyme was the key factor affecting the rutin content in the wort and beer. Compared to beer made using the common mashing method, the rutin content in the buckwheat beers produced using an improved mashing method was approximately 60 times higher. The total flavonoid contents in buckwheat beers also depended strongly on the mashing methods, ranging from 530.75 to 1,704.68 mg QE/l. The rutin-rich beers also showed better oxidative stability during forced-aging. Meanwhile, the buckwheat beers were found to be acceptable in terms of the main quality attributes, flavor, and taste.

Homological properties of modules over Ding-Chen rings

Gang Yang 대한수학회 2012 대한수학회지 Vol.49 No.1

The so-called Ding-Chen ring is an n-FC ring which is both left and right coherent, and has both left and right self FP-injective dimensions at most n for some non-negative integer n. In this paper, we investigate the classes of the so-called Ding projective, Ding injective and Gorenstein at modules and show that some homological properties of modules over Gorenstein rings can be generalized to the modules over Ding-Chen rings. We first consider Gorenstein at and Ding injective dimensions of modules together with Ding injective precovers. We then discuss balance of functors Hom and tensor.

Lung-specific delivery of paclitaxel by chitosan-modified PLGA nanoparticles via transient formation of microaggregates

Yang, Rui,Yang, Su-Geun,Shim, Won-Sik,Cui, Fude,Cheng, Gang,Kim, In-Wha,Kim, Dae-Duk,Chung, Suk-Jae,Shim, Chang-Koo Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of Pharmaceutical Sciences Vol.98 No.3

<P>Chitosan-modified paclitaxel-loaded poly lactic-co-glycolic acid (PLGA) nanoparticles with a mean diameter of 200–300 nm in distilled water were prepared by a solvent evaporation method. The mean diameter increased dramatically in contact with the mouse (CDF<SUB>1</SUB>) plasma, as a function of chitosan concentration in the modification solution (e.g., 2670.5 nm for 0.7% chitosan-modified nanoparticles, NP<SUB>3</SUB>), but reverted to almost its original size (i.e., 350.7 nm for NP<SUB>3</SUB>) following 5 min of gentle agitation. The zeta potential of PLGA nanoparticles was changed to positive by the chitosan modification. The in vitro uptake into, and cytotoxicity of the nanoparticles against, a lung cancer cell line (A549) were significantly increased by the modification. Most importantly, a lung-specific increase in the distribution index of paclitaxel (i.e., AUC<SUB>lung</SUB>/AUC<SUB>plasma</SUB>) was observed for chitosan-modified nanoparticles (e.g., 99.9 for NP<SUB>3</SUB> vs. 5.4 for Taxol™) when nanoparticles were administered to lung-metastasized mice via the tail vein at a paclitaxel dose of 10 mg/kg. Transient formation of aggregates in the blood stream followed by enhanced trapping in the lung capillaries, and electrical interaction-mediated enhanced uptake across the endothelial cells of the lung tumor capillary appear to be responsible for the lung-tumor-specific distribution of the chitosan modified nanoparticles. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 98:970–984, 2009</P>

Hydraulic components’ matching optimization design and entropy production analysis in a large vertical centrifugal pump

Gang Yang,Xutao Zhao,Desheng Zhang,Linlin Geng,Xueqi Yang,Xiongfa Gao 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.11

The large vertical centrifugal pump is the core power equipment for longdistance water division and large-scale irrigation projects. The power of the matching motor can reach 40 MW. In view of reducing the operating energy consumption of this kind of pump, the efficiency under the design condition was taken as the optimization objective, and a matching optimization on hydraulic components was proposed in this research. The optimization process was divided into two stages. The first stage focused on improving the configuration of the vane diffuser. In the second stage, the Plackett-Burman test design was used to screen out the optimization design variables of the vane diffuser and the volute, the optimal Latin hypercube sampling method was adopted to generate 106 sample cases, and an automatic numerical simulation optimization platform was built. Then, different approximate models were employed to construct the relationship between the optimization design variables and the objective function, and their fitting accuracy and robustness were compared. Finally, the optimal design parameters were determined by particle swarm optimization, and entropy production theory was used to analyze the internal flow pattern of the model before and after optimization. Results showed that D 3 , b 4 , β 3 , and S 8 have the greatest impact on the hydraulic efficiency of the pump. The multilayer backpropagation neural network has a higher fitting accuracy and better robustness compared with the other three approximate models. The efficiency of the optimized model under the design condition is increased by 4.22 %, reaching 90.82 %. Reducing the number of layers and vanes of the diffuser and improving the matching of hydraulic components can dramatically improve the hydraulic performance and hump characteristics of large vertical centrifugal pumps. Entropy production theory is a reliable approach to visualizing flow loss. The turbulent flow dissipation in the vane diffuser can be reduced the most after optimization.

Research on Target Detection in Sports Video

Gang Liu,Yang Liu,Yang Wang,Jingmeng Sun 보안공학연구지원센터 2016 International Journal of Multimedia and Ubiquitous Vol.11 No.2

For moving objects detection, a background subtraction algorithm based on adaptive Gaussian mixture model is proposed in order to extract moving regions. The OTSU algorithm is researched in order to adapt to the changes in the background images; In order to accelerate model updating rate, a novel mechanism is the combination of expected sufficient statistics and L-recent window.

Combined Application of Dentin Noncollagenous Proteins and Odontogenic Biphasic Calcium Phosphate in Rabbit Maxillary Sinus Lifting

Yang Gang,Liu Xin,Huang Tianyu,Ding Ruyuan,Wang Yuanyin 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.1

BACKGROUND: Teeth can be used as a raw material for preparing bone substitutes due to their similar chemical composition to bone. The objective of our study was to evaluate the effect of odontogenic biphasic calcium phosphate (BCP) incorporating dentin noncollagenous proteins (DNCPs) on osteogenesis and stability in maxillary sinus augmentation. METHODS: The composition, structure and morphology of the odontogenic BCP were tested by X-ray powder diffraction (XRD), Brunauer–Emmett–Teller, and scanning electron microscopy methods. The biocompatibility and osteoinduction of DNCPs and materials were examined in vitro and their bone regeneration capacity was verified in vivo. RESULTS: The results showed that the cells adhered and proliferated well on the DNCP-loaded BCP scaffold. The odontogenic BCP and DNCPs promoted osteogenic differentiation of cells, The new bone formation in the BCP groups and DNCP subgroups was significantly higher than the new bone formation in the control, and the new bone quality was better. The bone regeneration effect of odontogenic BCP was similar to the effect of deproteinized bovine bone mineral, but b- TCP did not maintain the height and volume of bone reconstruction. CONCLUSION: In conclusion, the combined application of DNCPs and odontogenic BCP is an effective strategy for tissue engineering osteogenesis in the maxillary sinus region. The biomimetic strategy could provide a new approach for patients requiring maxillary sinus lifting.

A comparative experimental study on the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films

Yang Gang,Pan Jiahui,Fu Xuecheng,Hu Zhiyu,Wang Ying,Wu Zhimao,Mu Erzhen,Yan Xue-Jun,Lu Ming-Hui 나노기술연구협의회 2018 Nano Convergence Vol.5 No.22

Thermoelectric multilayer thin films used in nanoscale energy conversion have been receiving increasing attention in both academic research and industrial applications. Thermal transport across multilayer interface plays a key role in improving thermoelectric conversion efficiency. In this study, the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films have been measured using time-domain thermoreflectance method. The interface morphology features of multilayer thin film samples were characterized by using scanning and transmission electron microscopes. The effects of interface microstructure on the cross-plane thermal conductivities of the multilayer thin films have been extensively examined and the thermal transfer mechanism has been explored. The results indicated that electron–phonon coupling occurred at the semiconductor/metal interface that strongly affected the cross-plane thermal conductivity. By appropriately optimizing the period thickness of the metal layer, the cross-plane thermal conductivity can be effectively reduced, thereby improving the thermoelectric conversion efficiency. This work presents both experimental and theoretical understanding of the thermal transport properties of Sb2Te3/metal multilayer thin film junctions with important implications for exploring a novel approach to improving the thermoelectric conversion efficiency. Introduction Thermoelectric multilayer thin films used in nanoscale energy conversion have been receiving increasing attention in both academic research and industrial applications. Thermal transport across multilayer interface plays a key role in improving thermoelectric conversion efficiency. In this study, the cross-plane thermal conductivities of nano-constructed Sb2Te3/(Cu, Ag, Au, Pt) thermoelectric multilayer thin films have been measured using time-domain thermoreflectance method. The interface morphology features of multilayer thin film samples were characterized by using scanning and transmission electron microscopes. The effects of interface microstructure on the cross-plane thermal conductivities of the multilayer thin films have been extensively examined and the thermal transfer mechanism has been explored. The results indicated that electron–phonon coupling occurred at the semiconductor/metal interface that strongly affected the cross-plane thermal conductivity. By appropriately optimizing the period thickness of the metal layer, the cross-plane thermal conductivity can be effectively reduced, thereby improving the thermoelectric conversion efficiency. This work presents both experimental and theoretical understanding of the thermal transport properties of Sb2Te3/metal multilayer thin film junctions with important implications for exploring a novel approach to improving the thermoelectric conversion efficiency. Introduction

A Scheme Design and Configuration Model of Mechanical Equipment Processing Technology based on Polychromatic Sets Theory

Gang Yang,Kangwei Chen 보안공학연구지원센터 2014 International Journal of Control and Automation Vol.7 No.11