• Title/Summary/Keyword: system uncertainty

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Performance Analysis of Load Control Model for Navigation/Guidance System on Flying Object (비행 물체의 유도제어 시스템 설계를 위한 하중(중력수) 제어 모델의 성능분석)

  • Wang, Hyun-Min;Woo, Kwang-Joon;Huh, Kyung-Moo
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.46 no.1
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    • pp.87-96
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    • 2009
  • In conventional method, flight model is discribed to differential equation by linealization of nonlinear object motion equation. As state equation from differential equation of moving object, the controller is designed by transfer functions of each module under discrimination of stability criteria. But this conventional method is designed under limitation of nonlinearity from object's shape and speed. In other word, The greater part of guidance/navigation system was satisfied with the result of good performance for normal figure of flight object, not sudden changed flight condition, not high speed. But it is not able to give full play to its ability on flight object which has abnormal figure, sudden changeable motion, high speed. Therefore, in this paper was presented performance analysis of load control model for navigation/guidance system on flying object being uncertainty, non-linear like abnormal figure, sudden changeable motion, high speed and is presented method of trajectory control(controllability) ahead of controllability and stability to achieve flight mission. In other word, this paper shows the first step of Min-design method and flight control model.

The Fuzzy QFD Approach to Importance the Public Sector Information Performance Measurement Category (퍼지 QFD를 활용한 공공부문 정보화 성과 측정범주 중요도 도출)

  • Oh, Jin-Seok;Song, Young-Il
    • Information Systems Review
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    • v.12 no.2
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    • pp.189-203
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    • 2010
  • Is presenting guidance of information performance measurement as government PRM version 2.0 these common reference models in public sector. Government PRM is consisted of assessment classification system and standard line of sight and performance management standard form. Through this, is sorting performance element and define cause-and effect. Government PRM is supplying measurement categories at assessment classification system, but relative importance for application standard by measurement categories is not presenting. In this study, importance for government PRM's measurement categories been applying by commonness Test of information performance measurement of public sector wishes to deduce estimation and priority. Research model used Fuzzy QFD, and designed so that can reflect well PRM's development purpose. I applied Fuzzy AHP and FPP method that graft together fuzzy theory to minimize uncertainty and ambiguity in that expert opinion. Is drawn to element that "Standard model offer for information department and management" is the most important in government PRM's development purpose. "Quality of service" is showing the highest priority in customer results in measurement category. Importance for government PRM's measurement categories can offer common valuation basis in government and public institution. Hereafter if examine closely quantitative cause-and effect for structure model of measurement classification system when study government PRM more objective and efficient reference model become.

Development of District-level Planning Support System by using GIS (GIS를 활용한 상세계획 지원시스템의 개발)

  • 고준환;주용수
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.16 no.2
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    • pp.251-258
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    • 1998
  • The purpose of this study is to develop the District-level Planning Support System (DPSS) by using GIS. The district-level planning which is related for district-level control of city, needs the various parcel-level information which is composing the urban physical environment. The information has to be stored and analyzed for recognizing the study area, then the district-level planning will be efficiently managed. The use of GIS in the process of district-level planning is restricted for the creation of thematic map. GIS is not used for the analysis of spatial patterns and planning process. This study evaluates the characteristics of current district-level planning and the basic components of urban physical environment. And the database model is built. The topology among components is defined by using the spatial relationship. Then the spatial query machine for district-level planing is developed by using ArcView 3.1, Avenue and Dialog Extension. This spatial query machine is applied for case study. This study shows 1) the possibility of the district-level planning support system for analyzing spatial relationship, 2) the needs of the up-to-date topographic map showing current building's footlines and the complete integration with cadastral maps, it will reduce the uncertainty in the spatial decision making process, 3) the methodology for the construction of spatial decision making rules, 4) the further study for the using of raster, network, image and three dimension data.

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Data processing system and spatial-temporal reproducibility assessment of GloSea5 model (GloSea5 모델의 자료처리 시스템 구축 및 시·공간적 재현성평가)

  • Moon, Soojin;Han, Soohee;Choi, Kwangsoon;Song, Junghyun
    • Journal of Korea Water Resources Association
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    • v.49 no.9
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    • pp.761-771
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    • 2016
  • The GloSea5 (Global Seasonal forecasting system version 5) is provided and operated by the KMA (Korea Meteorological Administration). GloSea5 provides Forecast (FCST) and Hindcast (HCST) data and its horizontal resolution is about 60km ($0.83^{\circ}{\times}0.56^{\circ}$) in the mid-latitudes. In order to use this data in watershed-scale water management, GloSea5 needs spatial-temporal downscaling. As such, statistical downscaling was used to correct for systematic biases of variables and to improve data reliability. HCST data is provided in ensemble format, and the highest statistical correlation ($R^2=0.60$, RMSE = 88.92, NSE = 0.57) of ensemble precipitation was reported for the Yongdam Dam watershed on the #6 grid. Additionally, the original GloSea5 (600.1 mm) showed the greatest difference (-26.5%) compared to observations (816.1 mm) during the summer flood season. However, downscaled GloSea5 was shown to have only a -3.1% error rate. Most of the underestimated results corresponded to precipitation levels during the flood season and the downscaled GloSea5 showed important results of restoration in precipitation levels. Per the analysis results of spatial autocorrelation using seasonal Moran's I, the spatial distribution was shown to be statistically significant. These results can improve the uncertainty of original GloSea5 and substantiate its spatial-temporal accuracy and validity. The spatial-temporal reproducibility assessment will play a very important role as basic data for watershed-scale water management.

Storm Surge Vulnerability Assessment due to Typhoon Attack on Coastal area in Korea (태풍 내습으로 인한 연안역 해일 취약성 평가)

  • Kang, Tae-Soon;Oh, Hyeong-Min;Lee, Hae-Mi;Eum, Ho-Sik
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.21 no.5
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    • pp.608-616
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    • 2015
  • In this study, we have estimated the storm surge heights using numerical modeling on coastal area, and then evaluated the vulnerability index by applying the vulnerability assessment techniques. Surge modelling for 27 typhoons affected from 2000 to 2014 were simulated by applying the ADCIRC model. The results of validation and verification was in significant agreement as compared with observations for the top 6 ranking typhoons affected. As results, the storm surge heights in Jinhae Bay, Sacheon Bay, Gwangyang Bay, Cheonsu Bay and Gyeonggi Bay were higher than other inner coastal areas, then storm surge vulnerability assessment was performed using a standardization, normalization and gradation of storm surge heights. According to results of storm surge vulnerability assessment, index of Jinhae Bay, Sacheon Bay, Gwangyang Bay etc. are estimated to be vulnerable(4~5) because of the characteristics of storm surge such as inner bay are vulnerable compared with exposed to the open sea areas. However, index in the inner bay of western Jeonnam are not vulnerable(1~3) relatively. It may not appear the typhoons affected significantly for the past 15 years. So, the long-term vulnerability assessment with the sensitivity of geomorphology are necessary to reduce the uncertainty.

Appraisal of spatial characteristics and applicability of the predicted ensemble rainfall data (강우앙상블 예측자료의 공간적 특성 및 적용성 평가)

  • Lee, Sang-Hyeop;Seong, Yeon-Jeong;Kim, Gyeong-Tak;Jeong, Yeong-Hun
    • Journal of Korea Water Resources Association
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    • v.53 no.11
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    • pp.1025-1037
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    • 2020
  • This study attempted to evaluate the spatial characteristics and applicability of the predicted ensemble rainfall data used for heavy rain alarms. Limited area ENsemble prediction System (LENS) has 13 rainfall ensemble members, so it is possible to use a probabilistic method in issuing heavy rain warnings. However, the accessibility of LENS data is very low, so studies on the applicability of rainfall prediction data are insufficient. In this study, the evaluation index was calculated by comparing one point value and the area average value with the observed value according to the heavy rain warning system used for each administrative district. In addition, the accuracy of each ensemble member according to the LENS issuance time was evaluated. LENS showed the uncertainty of over or under prediction by member. Area-based prediction showed higher predictability than point-based prediction. In addition, the LENS data that predicts the upcoming 72-hour rainfall showed good predictive performance for rainfall events that may have an impact on a water disaster. In the future, the predicted rainfall data from LENS are expected to be used as basic data to prepare for floods in administrative districts or watersheds.

Evaluation of the Clark Unit Hydrograph Parameters Considering Basin and Meteorologic at Conditions : 1. Selection and Analysis of Representative Storm Events (유역 및 기상상태를 고려한 Clark 단위도의 매개변수 평가: 1. 대표 호우사상의 선정 및 분석)

  • Yoo, Chul-Sang;Kim, Kee-Wook;Lee, Ji-Ho
    • Journal of Korea Water Resources Association
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    • v.40 no.2 s.175
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    • pp.159-170
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    • 2007
  • This study evaluated the parameters of Clark unit hydrograph (UH) estimated using the rainfall-runoff measurements and evaluated their variability. This also includes the quantification of basin and meteorological factors using probability density functions, selection of storm events with mean affecting factors, and derivation of average parameters of the Clark UH from storm events selected. Summarizing the results from this procedure are as follows. (1) It is not easy to avoid much uncertainty on the decision of runoff characteristics (that is, the concentration time and storage coefficient) even with some rainfall-runoff events are available. (2) As the distribution function of concentration time is very skewed, a simple arithmetic mean may lead a biased estimate. That is, the arithmetic mean based on the normal distribution can not be representative anymore. The mode may well be the representative in this case. On the other hand, the storage coefficient shows a symmetric distribution function, so the arithmetic mean may be used use for its representative. For the basin in this study, the concentration time in this study is estimated to be about 7 hours, and the storage coefficient about 22 hours.

Vulnerability Assessment of Landslide by Heavy Rain to Establish Climate Change Adaptation Plan for Local Governments (지자체 기후변화 적응계획 수립지원을 위한 집중호우에 의한 산사태 취약성 평가)

  • Lee, Dong-kun;Kim, Ho Gul;Baek, Gyoung Hye;Seo, Changwan;Kim, Jaeuk;Song, Changkeun;Yu, Jeong Ah
    • Journal of Climate Change Research
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    • v.3 no.1
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    • pp.39-50
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    • 2012
  • KMA(Korea Meteorological Administration) projected that annual mean temperatures of South Korea will rise $3.8^{\circ}C$ and the annual total precipitation will increase by 17 percent by 2100. Rainfall is concentrated during the summer in South Korea. Thus the risk of landslide by heavy rain is expected to increase. After the landslide of Mt. Umyeon occurred in July 2011, disaster of forest sector is highlighted. Therefore vulnerability assessment of landslide is urgent. However, vulnerability assessment based on local governments was not done yet. In this study, we assess vulnerability of landslide by heavy rain for local governments. We used several scenarios to consider uncertainty of climate change. Through this study, local governments can use the results to establish adaptation plans. Also, the results could be used to decrease vulnerability of landslide.

A Study on the need of the Conversion of Fire Services to State Affairs (소방사무의 국가사무로의 전환 필요성에 관한 연구)

  • Lee, Jae-Hak;Jang, Seong-Ho
    • The Journal of the Korea Contents Association
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    • v.21 no.7
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    • pp.281-290
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    • 2021
  • The scope of fire services has been expanded from local fire prevention to rescue and first aid services, and the fire services system has been converted from an autonomous fire services system to a wide-area fire services system, and the status of fire officers has been unified as a national public servant. However, the underlying problem remains unsolved. One is a problem related to the conversion of fire services to state affairs, and the other is that Fire officers converted to national public servants are in charge of fire services which are evaluated as local autonomous affairs. The controversy over the nature of fire service stems from uncertainty and redundancy in the coordination of office function and distribution between the State and Local governments, and incomplete legislation that fundamentally fails to achieve systematic unity of office work and status. The fire service has a national responsibility as an affair that includes the existence of the state and the welfare and order of the people along with the police affairs. That is, affairs related to the safety of the people that protect the lives, bodies and properties of the people should be understood as State affairs. 「The LOCAL AUTONOMY ACT」 stipulates that local governments cannot perform State affairs such as affairs necessary for the existence of the nation, affairs requiring performance in a uniform manner throughout the nation, and affairs of nationwide or similar scale unless otherwise provided by the law. Fire Service should be regarded as such affairs. Considering that the rights to the safety and life of the people and the duty to protect the people are the duty of the nation, it is necessary to keep in mind that the reason for the change fire officers to the national public servants was not basically just a matter of treatment and finance.

Development of a Noble Gas Isotope Dilution Mass Spectrometric System Combined with a Cryogenic Cold Trap (초저온 냉각 트랩을 결합한 비활성기체 동위원소 희석 질량분석 시스템의 제작)

  • HONG, BONGJAE;SHIN, DONGYOUB;PARK, KEYHONG;HAHM, DOSHIK
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.27 no.3
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    • pp.144-157
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    • 2022
  • Noble gases, which are chemically inert and behave conservatively in marine environments, have been used as tracers of physical processes such as air-sea gas exchange, mixing of water masses, and distribution of glacial meltwater in the ocean. For precise measurements of Ne, Ar, and Kr, we developed a mass spectrometric system consisting of a quadrupole mass spectrometer (QMS), a high vacuum preparation line, an activated charcoal cryogenic trap (ACC), and a set of isotope standard gases. The high vacuum line consists of three sections: (1) a sample extraction section that extracts the dissolved gases in the sample and mixes them with the standard gases, (2) a gas preparation section that removes reactive gases using getters and separates the noble gases according to their evaporation points with the ACC, and (3) a gas analysis section that measures concentrations of each noble gas. The ACC attached to the gas preparation section markedly lowered the partial pressures of Ar and CO2 in the QMS, which resulted in a reduced uncertainty of Ne isotope analysis. The isotope standard gases were prepared by mixing 22Ne, 36Ar, and 86Kr. The amounts of each element in the mixed standard gases were determined by the reverse isotope dilution method with repeated measurements of the atmosphere. The analytical system achieved precisions for Ne, Ar, and Kr concentrations of 0.7%, 0.7%, and 0.4%, respectively. The accuracies confirmed by the analyses of air-equilibrated water were 0.5%, 1.0%, and 1.7% for Ne, Ar, and Kr, respectively.