• Title/Summary/Keyword: Data restoration

Search Result 1,429, Processing Time 0.028 seconds

A Study on the Power System Restoration Simulator (전력계통 고장복구 교육 시스템에 관한 연구)

  • Lee H.J.;Park S.M.;Lee K.S.;Lee J.G.;Min S.W.;Han C.K.;Park J.K.;Moon Y.H.
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.54 no.7
    • /
    • pp.323-327
    • /
    • 2005
  • This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using power flow calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the power flow(PF) module, data conversion(COW) module and GU subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. COW module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI subsystem is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.

Spatiotemporal Changes of the Thermal Environment by the Restoration of an Inner-city Stream (도시 내부 하천 복원에 의한 열 환경의 시공간적 변화)

  • Kwon, Tae Heon;Kim, Kyu Rang;Byon, Jae-Young;Choi, Young-Jean
    • Journal of Environmental Impact Assessment
    • /
    • v.18 no.6
    • /
    • pp.321-330
    • /
    • 2009
  • Spatiotemporal changes in the thermal environment in a large city, Seoul, Korea were analyzed using a thermal index, perceived temperature (PT), to standardize the weather conditions. PT is a standard index for the thermal balance of human beings in thermophysiological environment. For the analysis of PT, the data from long-term monitoring and intensive observations in and around the inner-city stream called 'Cheonggye' in Seoul, were compared with a reference data from the Seoul weather station. Long-term data were monitored by installing two automatic weather stations at 66m (S1) and 173m (S2) away from the center of the stream. Through the analysis of the data during the summer of 2006 and intensive observation periods, it was revealed that the stream's effects on the PT extended up to the distance of the S1 site. In winter, the increase of the PT between pre- and post-restoration was stronger at S1, which was nearer than S2 from the stream. These results suggest that PT can be used as an effective model in analyzing the changes of the thermal environment in relation with the changes of water surface areas.

A study on the power system restoration simulator (전력계통 고장복군 교육 시스템에 관한 연구)

  • Lee, H.J.;Kim, J.M.;Lee, K.S.;Park, S.M.;Song, I.J.;Lee, N.H.;Bae, J.C.;Hwang, B.H.
    • Proceedings of the KIEE Conference
    • /
    • 2003.07a
    • /
    • pp.181-183
    • /
    • 2003
  • This paper presents an operator training simulator for power system restoration against massive black-out. The system is designed especially focused on the generality and convenient setting up for initial condition of simulation. The former is accomplished by using on line calculation methodology, and PSS/E data is used to define the initial situation. The proposed simulator consists of three major components - the Power flow(PF) module, data conversion(CONV) module and CUI subsystem. PF module calculates power flow, and then checks overvoltage of buses and overflow of lines. CONV module composes an Y-Bus array and a data base at each restoration action. The initial Y-Bus array is constructed from PSS/E data. The user friendly GUI module is developed including graphic editor and built-in operation manual. As a result, the maximum processing time for one step operation is 15 seconds, which is adequate for training purpose. Comparison with PSS/E simulation proves the accuracy and reliability of the training system.

  • PDF

Seed collection strategies for plant restoration with the aid of neutral genetic diversity

  • CHUNG, Mi Yoon;SON, Sungwon;MAO, Kangshan;LOPEZ-PUJOL, Jordi;CHUNG, Myong Gi
    • Korean Journal of Plant Taxonomy
    • /
    • v.49 no.4
    • /
    • pp.275-281
    • /
    • 2019
  • One key step in the plant restoration process is the collection of seeds from the field. For the selection of source populations of target plant species for translocation purposes (reintroduction or reinforcements), several approaches are possible. A practical method involves the use of data from reciprocal transplant studies. If no direct data are available, knowledge of population genetics and the phylogeography of the target species can serve as an alternative. In this short review, we briefly propose guidelines for those collecting seeds for plant species restoration based on population genetics theory, focusing on two main questions: Where does the plant material come from and how are sources designated, and how are seeds efficiently collected from local populations? While genetic data on a larger scale (phylogeography and population genetics) are needed to form a reply to the first question, similar data on a smaller scale (fine-scale genetic structures within populations) are necessary to shed light on the second issue.

Numerical data processing on expert system for power system fault restoration - in IBM PC Turbo prolog - (계통 사고 복구 전문가 시스템에서의 수치 데이타 처리 - IBM PC 용 Turbo prolog 에서 -)

  • Choi, Joon-Young;Park, In-Gyu;Park, Jong-Keun
    • Proceedings of the KIEE Conference
    • /
    • 1987.11a
    • /
    • pp.316-320
    • /
    • 1987
  • This paper deals with expert system for power system fault restoration and accompanying numerical data processing. Nowadays, expert system which is a branch or artificial intelligence expands its application area to many fields. And it requires computer language for A.I. to be versatile. Expert system for power system handles numerous numerical data and language for A.I. has its deficiency in numerical data processing. However some recent version of the A.I. language rind ways of overcoming this dilemma by giving the way or linking conventional algorithmic languages to them. This study presents numerical data processing routines described in Turbo prolog which is run in IBM PC and linking numerical data processing routines written in Turbo C to Turbo prolog.

  • PDF

Improved Fuzzy-associated Memory Techniques for Image Recovery

  • Zheng Zhao;Kwang Baek Kim
    • Journal of information and communication convergence engineering
    • /
    • v.22 no.3
    • /
    • pp.242-248
    • /
    • 2024
  • This paper introduces an improved fuzzy association memory (IFAM), an advanced FAM method based on the T-conorm probability operator. Specifically, the T-conorm probability operator fuzzifies the input data and performs fuzzy logic operations, effectively handling ambiguity and uncertainty during image restoration, which enhances the accuracy and effectiveness of the restoration results. Experimental results validate the performance of IFAM by comparing it with existing fuzzy association memory techniques. The root mean square error shows that the restoration rate of IFAM reached 80%, compared to only 40% for the traditional fuzzy association memory technique.

An Analysis of Landscape Change Factors on Restoration Project of Ecological Ridgeline using Landscape Adjectives -Focused on Frontal View- (경관형용사를 활용한 생태축 복원사업의 경관변화요인 분석 - 정면경관을 대상으로-)

  • Lee, Woo-Sung;Park, Yeong Dae;Kwon, Tae-Ho
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.20 no.1
    • /
    • pp.97-115
    • /
    • 2017
  • The purpose of this study is to evaluate the preference and image on landscape of before and after the restoration in the four study areas where the restoration project of Baekdudaegan ecological ridgeline was carried out and to explore the change factors of image preference according to restoration project. The study areas were Beoljae, Ihwaryeong, Bijoryeong, and Yuksimnyeong and 248 questionnaires were used for analysis. As a result of the recognition analysis on restoration project of ecological ridgeline, the awareness of the project was low at 2.63, the satisfaction of the project was 3.42, and necessity of the project was 4.07. In terms of the preference analysis for landscape photographs, the all preferences of four sites were improved after the project than before. In the result of the landscape image evaluation, images such as 'lifeless', 'uniform' and 'ugly' were high before the project, however, images such as 'clean', 'tidy', and 'stable' were high after the project. As a result of analyzing the change factors of image preference according to the restoration project, adjectives such as 'beautiful-ugly' and 'open-closed' influenced the preference change in common. These findings can be utilized as the base data for the planning direction for the construction of new ecological ridgeline or the landscape conservation of existing ecological ridgeline.

COMPARISON OF MARGINAL LEAKAGE OF WEDGE-SHAPED CLASS V CAVITY ACCORDING TO RESTORATIVE MATERIALS (쐐기 형태의 5급와동에서 수복재료에 따른 변연 미세누출의 비교)

  • Jang, Hyun-Joo;Lee, Hee-Joo;Hur, Bock
    • Restorative Dentistry and Endodontics
    • /
    • v.25 no.1
    • /
    • pp.56-62
    • /
    • 2000
  • The purpose of this study was to assess the effects of restorative materials on the marginal leakage of wedge-shaped class V cavity. The study was performed in vitro in 25 defect-free permanent, extracted teeth. Wedge-shaped class V cavities were prepared and then the teeth were randomly selected and restored according to the following. Group A : restoration with Tetric Ceram(composite resin) Group B : restoration with Tetric flow(flowable resin) Group C : restoration with Compoglass after acid etching(compomer) Group D : restoration with Compoglass(compomer) Group E : restoration with Fuji II LC improved(resin-modified GIC) After thermocycling, the specimens were immersed in 5% basic fuchsin solution for 6 hours and sectioned longitudinally through the center of the restoration. The degree of marginal leakage was measured as the extent of dye penetration under the stereomicroscope. The data were analysed using one-way ANOVA. When significant differences found, multiple comparisons were made using Duncan's Multiple Range Test. The results were as follows: 1. The occlusal margins of all groups except for Fuji II LC improved showed lesser leakage than gingival margins and there was statistically significant difference(p<0.05). 2. At the occlusal margins, group A, B showed same marginal leakage scores, and others were decreased as group C, D, E in that order. There were statistically significant difference between group A, Band group D, E, group C and group E(p<0.05). 3. At the gingival margins, group B, C showed same marginal leakage scores, and others were decreased as group A, D, E in that order. But there was statistically significant difference between group B, C and group E(p<0.05). 4. In the Compoglass restoration, acid-etching technique was beneficial for marginal sealing ability at all of margins. But there was no statistically significant difference (p>0.05). In the restorations for wedge-shaped class V cavities, resin restoration with acid etching technique is recommended.

  • PDF

Cloud Detection and Restoration of Landsat-8 using STARFM (재난 모니터링을 위한 Landsat 8호 영상의 구름 탐지 및 복원 연구)

  • Lee, Mi Hee;Cheon, Eun Ji;Eo, Yang Dam
    • Korean Journal of Remote Sensing
    • /
    • v.35 no.5_2
    • /
    • pp.861-871
    • /
    • 2019
  • Landsat satellite images have been increasingly used for disaster damage analysis and disaster monitoring because they can be used for periodic and broad observation of disaster damage area. However, periodic disaster monitoring has limitation because of areas having missing data due to clouds as a characteristic of optical satellite images. Therefore, a study needs to be conducted for restoration of missing areas. This study detected and removed clouds and cloud shadows by using the quality assessment (QA) band provided when acquiring Landsat-8 images, and performed image restoration of removed areas through a spatial and temporal adaptive reflectance fusion (STARFM) algorithm. The restored image by the proposed method is compared with the restored image by conventional image restoration method throught MLC method. As a results, the restoration method by STARFM showed an overall accuracy of 89.40%, and it is confirmed that the restoration method is more efficient than the conventional image restoration method. Therefore, the results of this study are expected to increase the utilization of disaster analysis using Landsat satellite images.

Evaluation of Channel-forming Discharge for the Abandoned Channel Restoration Design of Cheongmi Stream (청미천 구하도 복원 설계를 위한 하도형성유량 산정)

  • Ji, Un;Kang, Jun-Gu;Yeo, Woon-Kwang;Han, Seung-Won
    • Journal of Korea Water Resources Association
    • /
    • v.42 no.12
    • /
    • pp.1113-1124
    • /
    • 2009
  • The abandoned channel restoration is one of methods to enhance the environmental function and ecological habitat as well as the functions of water-utilization and flood control. The channel-forming or dominant discharge must be evaluated and defined to design the cross-sectional and plane geometries of the stable and equilibrium channel for the abandoned channel restoration project. In general, bankfull discharge, specified recurrence interval discharge, and effective discharge have been used to decide the channel-forming discharge. In this study, bankfull discharge, specified recurrence interval discharge, and effective discharge were calculated and compared for the abandoned channel restoration site of Cheongmi Stream and their relations to historical bed changes were analyzed. The bankfull discharge, 488 $m^3/s$, of the abandoned channel restoration site of Cheongmi Stream was calculated using HEC-RAS data and ranged between 1.5-year and 2-year recurrence discharges. Also, the effective discharge evaluated with the sediment rating curve and mean daily discharge data is greater than the bankfull discharge. According to the survey data of 1994 and 2008, the bed elevation of the study reach was decreased over time. It is indicated that the channel bed is changing to the stable condition to allow the effective discharge.