• Title/Summary/Keyword: Order Imbalance

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Evaluation of Creative Space Efficiency in China' Provinces Based on AHP Method

  • Hu, Shan-Shan;Kim, Hyung-Ho
    • International journal of advanced smart convergence
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    • v.9 no.4
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    • pp.52-61
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    • 2020
  • The AHP method was used in 30 provinces of China to construct the index system of creative space efficiency evaluation and determine the weight of each index. The fuzzy comprehensive evaluation method was further used to score the indexes at all levels, and then the total efficiency score was sorted. The purpose of this study is to adjust the regional layout of creative space reasonably and implement financial policies accurately through the evaluation of the efficiency of creative space. The results is ranking top in weight of several indicators, which include the number of incubated Startups, the number of innovation and entrepreneurship mentors, the survival rate of incubator, the innovative training activities, etc. It was also found that Beijing, Shanghai, Jiangsu, Guangdong and Zhejiang ranked first in the score of creative space efficiency. This study is meaningful in that it was In order to effectively solve the problem of the imbalance of the creative space efficiency in China's province, by coordinating the regional pattern, establishing a sound service system and improving the efficiency evaluation system.

DTS-based Temperature Monitoring and Analysis of Battery Cell Deterioration Characteristics by Temperature Condition (DTS 기반 온도 감시 및 온도 조건에서의 배터리 셀 열화 특성 분석)

  • SoonJong, Kwon;Soo-Yeon, Kim;Jin, Hwang;Sang-Kyun, Woo;Bong-Suck, Kim
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.143-149
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    • 2022
  • As ESS safety issues increase recently, there is a need to more precisely monitor the temperature of the ESS. In this paper, DTS technology for temperature monitoring of ESS batteries is introduced and the temperature measurement principle is explained. The temperature of the battery module is measured using the DTS system, and the thermal deviation between battery cells inside the battery module is analyzed. In order to analyze how thermal imbalance affects the charging and discharging performance of the battery, an accelerated degradation test was conducted. Cycle life characteristics analysis, battery surface temperature change, and AC impedance characteristics were conducted to analyze how the performance of battery cells differs according to temperature conditions.

Analysis of Control Stability and Performance of Magnetically-Levitated Flywheel Energy Storage System using Flexible Rotor Model (유연체 회전축 모델을 이용한 자기부상형 플라이휠 에너지 저장장치의 제어시스템 안정성 및 성능 해석)

  • Yoo, Seong-Yeol;Lee, Wook-Ryun;Bae, Yong-Chae;Noh, Myoung-Gyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2009.10a
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    • pp.258-263
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    • 2009
  • This paper describes an analysis of the stability and performance of a large-capacity flywheel energy storage system (FESS) supported by active magnetic bearings. We designed and manufactured the system that can store up to 5kWh of usable energy at the maximum speed of 18,000 rpm. In order to analyze the stability of the systems accurately, we derived a rigid body rotor model, flexible rotor model using finite-element method, and a reduced-order model using modal truncation. The rotor model is combined with those of active magnetic bearings, amplifiers, and position sensors, resulting in a system simulation model. This simulation model is validated against experimental measurements. The stability of the system is checked from the pole locations of the closed-loop transfer functions. We also investigated the sensitivity function to quantify the robustness of the systems to the disturbances such as mass imbalance and sensor noises.

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A Study on EV Charging Scheme Using Load Control

  • Go, Hyo-Sang;Cho, In-Ho;Kim, Gil-Dong;Kim, Chul-Hwan
    • Journal of Electrical Engineering and Technology
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    • v.12 no.5
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    • pp.1789-1797
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    • 2017
  • It is necessary to charge electric vehicles in order to drive them. Thus, it is essential to have electric vehicle charging facilities in place. In the case of a household battery charger, the power similar to that consumed by a household with a basic contract power of 3kW is consumed. In addition, many consumers who own an electric vehicle will charge their vehicles at the same time. The simultaneous charging of electric vehicles will cause the load to increase, which then will lead to the imbalance of supply and demand in the distribution system. Thus, a smart charging scheme for electric vehicles is an essential element. In this paper, simulated conditions were set up using real data relating to Korea in order to design a smart charging technique suitable for the actual situation. The simulated conditions were used to present a smart charging technique for electric vehicles that disperses electric vehicles being charged simultaneously. The EVs and Smart Charging Technique are modeled using the Electro Magnetic Transients Program (EMTP).

Effects of Changes in Postural Alignment on Foot Pressure and Balance of Patients with Stroke (뇌졸중 환자에서 자세정렬변화가 족저압 및 균형에 미치는 영향)

  • Yang, Dae-Jung;Park, Seung-Kyu;Kang, Jeong-Il;Park, Seong-Bin
    • The Journal of Korean Physical Therapy
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    • v.26 no.4
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    • pp.226-233
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    • 2014
  • Purpose: This study was conducted in order to investigate the exercise limit that may occur depending on changes in postural alignment by examining the significance of postural alignment changes, foot pressure, and balance of patients with stroke. Methods: In this study, 50 patients diagnosed with a stroke were selected as subjects. Imbalance of postural alignment of the trunk, pelvic tilt of trunk rotation of the body, angle of kyphotic curving of the thoracic, and angle of lordotic curving of the lumbar vertebra were measured. Foot pressure was examined by measuring average pressure and weight bearing. Balance was examined by measuring the center of pressure and limit of stability. Results: The significance of postural alignment, foot pressure, and weight bearing of the non-paretic side was examined. In addition, the significance between postural alignment and balance was examined. Conclusion: It is thought that limits of foot pressure and balance in the standing position can be caused by postural alignment. Thus, both a therapeutic intervention program and postural alignment training should be provided together in order to improve the function of patients with stroke.

A Camber Monitoring System of RM Zone based on Direction Selective Edge Detection Algorithm (방향 선택형 에지검출 알고리즘 기반의 RM존 캠버 모니터링 시스템)

  • Kim, Hyun-Soo;Choi, Yong Joon
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.8
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    • pp.713-717
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    • 2015
  • In this paper, we propose camber monitoring system which is using on hot rolling process. In roughing mill which is one of the rolling part in hot rolling process, steel plate can be bended in width direction under the imbalance of rolling condition. This bending of steel plate in width direction is called as camber. In order to measure the camber, first, cameras which are installed over transport pathway of steel plate take pictures of whole shape of steel plate. And location value of steel plate edge is extrated from these pictures by edge detection algorithm. But, there are a lot of noises which are generated by such as water sprays, dusts, peripheral equipments in these pictures, and these noises make edge detection difficult. In order to solve this kind of problem, we developed a direction selective edge detection algorithm, and applicated in our camber monitoring system. As a result, we got stable results in spite of process noises.

Minimum Bandwidth Regenerating Codes Based on Cyclic VFR Codes

  • Wang, Jing;Wang, Shuxia;Wang, Tiantian;Zhang, Xuefei
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.13 no.7
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    • pp.3583-3598
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    • 2019
  • In order to improve the reliability and repair efficiency of distributed storage systems, minimum bandwidth regenerating (MBR) codes based on cyclic variable fractional repetition (VFR) codes are constructed in this thesis, which can repair failed nodes accurately. Specifically, in order to consider the imbalance of data accessed by the users, cyclic VFR codes are constructed according to that data with different heat degrees are copied in different repetition degrees. Moreover, we divide the storage nodes into groups, and construct MBR codes based on cyclic VFR codes to improve the file download speed. Performance analysis and simulation results show that, the repair locality of a single node failure is always 2 when MBR codes based on cyclic VFR codes are adopted in distributed storage systems, which is obviously superior to the traditional MBR codes. Compared with RS codes and simple regenerating codes, the proposed MBR codes based on cyclic VFR codes have lower repair locality, repair complexity and bandwidth overhead, as well as higher repair efficiency. Moreover, relative to FR codes, the MBR codes based on cyclic VFR codes can be applicable to more storage systems.

Multi-scale context fusion network for melanoma segmentation

  • Zhenhua Li;Lei Zhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.18 no.7
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    • pp.1888-1906
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    • 2024
  • Aiming at the problems that the edge of melanoma image is fuzzy, the contrast with the background is low, and the hair occlusion makes it difficult to segment accurately, this paper proposes a model MSCNet for melanoma segmentation based on U-net frame. Firstly, a multi-scale pyramid fusion module is designed to reconstruct the skip connection and transmit global information to the decoder. Secondly, the contextural information conduction module is innovatively added to the top of the encoder. The module provides different receptive fields for the segmented target by using the hole convolution with different expansion rates, so as to better fuse multi-scale contextural information. In addition, in order to suppress redundant information in the input image and pay more attention to melanoma feature information, global channel attention mechanism is introduced into the decoder. Finally, In order to solve the problem of lesion class imbalance, this paper uses a combined loss function. The algorithm of this paper is verified on ISIC 2017 and ISIC 2018 public datasets. The experimental results indicate that the proposed algorithm has better accuracy for melanoma segmentation compared with other CNN-based image segmentation algorithms.

A Comparative Study on the Competitiveness of the Alignment Zones in the Capital Area (수도권 정비 권역별 입지 경쟁력 비교 연구)

  • Kim, Dong-Yoon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.11 no.3
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    • pp.79-88
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    • 2011
  • In the context of sustainability which is understood as equilibrium among three elements; human, space and time, the imbalance within the Seoul metropolitan area hinders its own area or the nation from development. Claims for the balanced development in the area are set up on the premise that there is a locational order of priority among the zones named 'overpopulation suppression', 'growth management' and 'conservation'. Based on the systematic consideration of competitiveness this study adopts the premise as a research hypothesis. Factor scales derived from the factor analysis, a kind of multivariate dependence analysis play an important role in this research process since they are measured by interval-ratio level and can be used for dependent variables in the statistical analysis. The hypothesis test carried out by means of the analysis of variance(ANOVA) concludes that the hypothesis assuming no difference in the competitiveness is rejected but the alternative hypothesis of the locational order mentioned above should be adjusted. Eigenvalues derived from the factor analysis could be used as weights for aggregate factor scales and the scales show that the priority is in the order of growth management - overpopulation suppression - conservation zones. This finding has also a significant implication that the countermeasures to cope with the lowering of the competitiveness resulted from the continuous and absolute restraints should be provided. And strategic approaches which are composed of key factors for each zone are deducted from in-depth review. (1) overpopulation suppression zone; health-welfare, educational base, public service factors, focusing on health-welfare one, (2) growth management zone; public service factor and (3) conservation zone; health-welfare, educational base factors, also focusing on health-welfare one.

Mold Technology for Precision Injection Lens (초정밀 사출렌즈 금형 기술)

  • Ha, Tae Ho;Jo, Hyoung Han;Song, Jun Yeob;Jeon, Jong
    • Journal of the Korean Society for Precision Engineering
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    • v.31 no.7
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    • pp.561-567
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    • 2014
  • Precision injection mold is an essential element in order to manufacture small and precision plastic lenses used for phone camera. There are many critical factors to meet the requested specifications of high quality plastic lenses. One of the main issues to realize high quality is minimizing decenter value, which becomes more critical as pixel numbers increases. This study suggests the method to minimize decenter value by modifying ejecting structure of the mold. Decenter value of injection-molded lens decreased to 1 ${\mu}m$ level from 5 ${\mu}m$ by applying suggested ejecting method. Also, we also developed BIS (Built-in Sensor) based smart mold system, which has pressure and temperature sensors inside of the mold. Pressure and temperature profiles from cavities are obtained and can be used for deduction of optimal injection molding condition, filling imbalance evaluation, status monitoring of injection molding and prediction of lens quality.