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.

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

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.

An automated longquan celadon glaze thickness measurement method based on optical coherence tomography

Yang Zhou,Longjie Shi,Gang Ceng,Tiebing Liu,Yang Shi,Zhengwei Chen,Fenglin Wang,Yuefeng Ceng 한양대학교 세라믹연구소 2020 Journal of Ceramic Processing Research Vol.21 No.3

The thickness of glaze is one of the important indicators in the quality evaluation of Longquan celadon. But till now, there isno automatic and non-destructive method to measure it. In order to satisfy this demand, an automated method has beenproposed to measure the glaze thickness based on optical coherence tomography (OCT) technique. According to themorphological characteristics of celadon glaze in OCT image, the proposed method locates the upper and lower boundariesof the glaze layer, then the glaze thickness is automatically calculated after the axial resolution calibration of the OCT imagesfor different categories of Longquan celadon. In the experiment, the glaze OCT images of 6 different categories of Longquanceladon were applied in the glaze thickness estimation. By comparing with the physical measuring result, this method is provedto be able to measure the glaze thickness rapidly and non-destructively and the performance is enough to meet the demandof the industrial application.

Safety Assessment Method for the Crane Structure Based on the Unacertained Measuring Theory

Yang Rui-gang,Lu Yi,Wang Lei,Xu Ge-ning 보안공학연구지원센터 2015 International Journal of u- and e- Service, Scienc Vol.8 No.8

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.

Facile and highly efficient fabrication of robust Ag nanowire-elastomer composite electrodes with tailored electrical properties

Yang, Ming,Kim, Sang Woo,Zhang, Shuye,Park, Dae Young,Lee, Chang-Woo,Ko, Yong-Ho,Yang, Haifeng,Xiao, Yong,Chen, Gang,Li, Mingyu The Royal Society of Chemistry 2018 Journal of Materials Chemistry C Vol.6 No.27

<P>The fabrication of Ag nanowire (AgNW) patterns on a working substrate is a critical step to prepare flexible/stretchable electronics. The conventional method of making AgNW patterns is based on a 2-D mask, which suffers some serious drawbacks, such as low material usage, difficulty in preparing complex patterns, and susceptibility to damaged pattern edges. To overcome these drawbacks, this study proposes the use of a 3-D mask, which when combined with a vacuum filtration system, allowed efficient fabrication of complex AgNW patterns with clear edges. In addition, we controlled the microstructure of the patterned AgNW/polydimethylsiloxane (PDMS) electrodes transferred from the membrane filter, obtaining stretchable electrodes with anisotropic electrical properties. Moreover, we greatly improved the stability and reliability of the patterned electrodes in long-term stretch/release tests by developing a PDMS/AgNW/PDMS sandwich structure. Based on these improvements, robust stretchable electrodes with a stretchability of over 80% uniaxial strain and tunable gauge factors ranging from 0.07 to 520 (a much wider range than previously reported) were fabricated by optimizing the AgNW deposition density and PDMS peel-off direction. Finally, we demonstrated the applicability of the proposed method by fabricating stretchable circuits which were able to either maintain a stable resistance or sensitively monitor various human motions, revealing its tremendous potential for applications in flexible/stretchable electronics.</P>

HOMOLOGICAL PROPERTIES OF MODULES OVER DING-CHEN RINGS

Yang, Gang Korean Mathematical Society 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.

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