• Title/Summary/Keyword: target quality

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A Study on Signal Processing of Target Discrimination Using RELAX in Millimeter-wave Seeker (밀리미터파 탐색기에서 RELAX 기법을 이용한 표적 식별 신호처리 기법)

  • Jo, Heejin;Kim, Minwoo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.18 no.3
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    • pp.253-259
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    • 2015
  • This paper introduces a signal processing technique for discrimination of missile target. In order to detect and discriminate the target, a seeker radar makes use of chirp waveform and stretch processing to generate high resolution range profiles(HRRPs). RELAX(relaxation) algorithm, which is one of the spectral estimation techniques, was used to find scattering centers of a missile from HRRP. From the information on the distribution of one-dimensional(1-D) scattering centers on a target, we can discriminate the target without noise.

A Study on Regional and Individual Preference Sound Quality for Luxury Vehicle (고급 차량음의 지역별 개인별 선호 음질에 관한 연구)

  • Kim, Seong-Hyeon;Park, Dong-Chul;Hong, Seok-Gwan
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2012.10a
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    • pp.364-369
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    • 2012
  • The vehicle sound classified into driving sound due to power-train, operating sound due to electric motor like sunroof, door lock and electronic sound. These vehicle sound has various features depend on the characteristic of sound that user required. And it based on cultural and regional difference of user. In this study, the user required vehicle sound characteristics for luxury sedan was investigated in overall viewpoint. And virtual target sound was developed through the result of user preference investigation. Next, Jury test was carried out in Germany, USA and Korea for evaluating the target sound. And the regional and individual difference of preference was analyzed through the result of jury test. This result of research will be contributed to design of vehicle sound quality and target sound setting.

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An Evaluation of Process Capability Using Degree of Conformance (적합성 정도를 이용한 공정능력의 평가)

  • Park, Sang-Gyu;Chung, Kyu-Ryun
    • Journal of Korean Society for Quality Management
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    • v.24 no.1
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    • pp.50-60
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    • 1996
  • Though the quality characteristics within a specified tolerance are equally desired quality there is a difference in conformance between a specification limit and a target value. In this paper we propose a measure of process capability that takes into account the degree of conformance to a target value as well as the process variation.

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Strategies for Robust Design with Multiple Responses

  • Hwang Inkeuk;Chung Lakchae
    • Journal of Korean Society for Quality Management
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    • v.25 no.2
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    • pp.28-46
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    • 1997
  • This paper considers robust design strategies for off-line quality control, with the use of experimental design and response surface methodology, in situations where all products have multiple quality characteristics. These strategies can be developed using the desirability concept of desirability functions to determine the settings of the design factors, not only to get the average performances on target but also to minimize variability around the target values.

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A Study on Process Capability Index using Reflected Normal Loss Function (역정규 손실함수를 이용한 공정능력지수에 관한 연구)

  • 정영배;문혜진
    • Journal of Korean Society for Quality Management
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    • v.30 no.3
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    • pp.66-78
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    • 2002
  • Process capability indices are being used as indicators for measurements of process capability for SPC of quality assurance system in industries. In view of the enhancement of customer satisfaction, process capability indices in which loss functions are used to deal with the economic loss In the processes deviated from the target, are in an adequate representation of the customer's perception of quality In this connection, the loss function has become increasingly important in quality assurance. Taguchi uses a modified form of the quadratic loss function to demonstrate the need to consider the proximity to the target while assessing its quality. But this traditional quadratic loss function is inadequate to assessing the quality and quality improvement since different processes have different sets of economic consequences on the manufacturing, Thereby, a flexible approach to the development of the loss function needs to be desired. In this paper, we introduce an easily understood loss function, based on reflection of probability density function of the normal distribution. That is, the Reflected Normal Loss function can be adapted to an asymmetric loss as well as to a symmetric loss around the target. We propose that, instead of the process variation, a new capability index, CpI using the Reflected Normal Loss Function that can accurately reflect the losses associated with the process and a new capability index CpI Is compared with the classical indices as $C_{p}$ , $C_{pk}$, $C_{pm}$ and $C_{pm}$ $^{+}$.>.+/./.

Analyzing the Spatio-temporal Trend in TMDL Water Quality for Gyeongnam Using Emerging Hot Spot Analysis (수질오염총량제 대응을 위한 경남 하천 수질의 시공간 경향성 분석)

  • Sun, Danbee;Kim, Jiho;Kim, Sangmin;Jang, Min-Won
    • Journal of Korean Society of Rural Planning
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    • v.26 no.4
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    • pp.53-65
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    • 2020
  • This study aimed to provide a basic information for managing the water quality of national and regional 1st rivers in Gyeongnam by analyzing the emerging hot spot patterns in BOD, T-P, and TOC, and by grouping the changing trends into clusters. The emerging hot spot analysis for each water quality item was implemented in ArcGIS Desktop with monthly water quality data from 96 water environmental monitoring stations in Gyeongnam, and then four patterns of water quality change were classified by the K-mean cluster analysis. As for BOD, persistent cold spot pattern covered about 42.9% of target rivers, and T-P concentration tended to be low or be getting lower at over 70% of target rivers. While, for TOC, about 70% of target rivers resulted in oscillating hot spots. In addition, the cluster analysis showed that the downstream of Nakdong river had the top priority in terms of water quality management because of the increasing concentration for all the three water quality.

Application of the Load Duration Curve (LDC) to Evaluate the Achievement Rate of Target Water Quality in the Nakdong River Unit Watersheds (부하지속곡선(LDC ; Load Duration Curve)을 활용한 낙동강수계 오염총량 단위유역 목표수질 평가방법 적용 방안)

  • Jung, Kang-Young;Kim, Hong Tae;Kim, Sang Soo;Kim, Shin;Shin, Dong Seok;Kim, Gyeong Hoon
    • Journal of Environmental Science International
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    • v.26 no.4
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    • pp.433-445
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    • 2017
  • In recent years, the United States has used the Load Duration Curve (LDC) method to identify water pollution problems, considering the size of the pollutant load in the entire stream flow condition to effectively evaluate Total Maximum Daily Loads (TMDLs). A study on the improvement of the target water quality evaluation method was carried out by comparing evaluations of two consecutive years of water quality and LDC data for 41 unit watersheds (14 main streams and 27 tributaries). As a result, the achievement rate of the target water quality evaluation method, according to current regulations, was 68-93%, and that by the LDC method was 82-93%. Evaluating the target water quality using the LDC method results in a reduction in the administrative burden and the total amount of planning as compared to the current method.

Evaluation of Stream Water Quality to Select Target Indicators for the Management of Total Maximum Daily Loads (수질오염총량관리 대상물질 선정을 위한 하천수질 평가)

  • Park, Jun Dae;Park, Jae Hong;Oh, Seung Young;Lee, Jae Kwan
    • Journal of Korean Society on Water Environment
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    • v.29 no.5
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    • pp.630-640
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    • 2013
  • It is one of the most critical steps identifying impaired waterbodies exactly in the selection of target water quality indicators for the management of Total Maximum Daily Loads (TMDLs). Excess ratio and excess level were applied and analyzed by the stream zone basis in order to evaluate water impairment for Nakdong, Geum, Youngsan and Seomjin rivers. Each river basin was divided into stream zones in the light of its watershed and waterbody characteristics. Selected water quality parameters discussed in this study were pH, DO, BOD, COD, SS, T-P, T-Coli and F-Coli. The excess ratios of the water quality parameters were used to discriminate water bodies that did not meet water quality standards. The excess levels were used to classify the degradation of water quality. The excess ratios and the excess levels to the water quality criteria of the medium influence areas were used for each stream zone. The results indicate that the excess ratios and the excess levels are varied on the stream zone in each river basin. Three parameters, pH, DO and SS, met water quality standards in all stream zones. The other five parameters indicated very high excess ratios in most waterbodies, and especially T-P and T-Coli revealed to be very high excess levels in some waterbodies. These parameters could be considered as major target indicators for the management of TMDLs.

Tracing Water Pollution Source using FDC and Exceedance Rate in Cheongmicheon Watershed (FDC 및 초과율을 이용한 청미천 유역에서의 오염원 추적)

  • Kim, Yeon-Su;Kim, Sang-Ho;Lee, Chang-Hee
    • Journal of Wetlands Research
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    • v.20 no.2
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    • pp.136-144
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    • 2018
  • The Ministry of the Environment conducts a water environment management plan and TMDL(Total Maximum Daily Load) for integrated watershed management, and determines whether the target water quality is achieved using water quality monitoring data. The concentration of monitoring points located in the downstream of the watershed is the outcome of complicated mechanisms such as influx of pollutants from the tributaries of the watershed and self-purification of river water. The purpose of this study is to analyze the effect of main stream and tributary water quality on the target water quality point using the water pollution source tracking and exceedance rate of watershed. In this study, FDC and exceedance rate analysis were performed on six water quality items including BOD and T-P, which are the targets of TMDL. Water quality items and points affecting the target water quality point were derived from flow rate. In this study, the pollution source tracking through FDC analysis and exceedance rate analysis will be able to establish more efficiently the water quality management strategy for each branch to achieve the target water quality.

A Study on the Estimation of River Management Flow in Urban Basin (도시유역의 하천유지용수 산정에 관한 연구)

  • 이영화
    • Journal of Environmental Science International
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    • v.5 no.3
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    • pp.377-385
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    • 1996
  • This study aims at the estimation of a river management flow in urban basin analyzing Sinchun basin to be the tributary of Kumho river basin. The river management flow has to satisfy a low flow as natural flow and an environmental preservation flow estimated by a dilution flow to satisfy a target water quality in drought flow. Therefore for the estimation of a river management flow in Sinchun in this study, first Tank model as a basin runoff model estimates a low flow, a drought flow from a flow duration curve in Sinchun, second QUAL2E model as water quality model simulates water quality in Sinchun and estimates environmental preservation flow to satisfy a target water qua%its, BOD 8 mg/l by a dilution flow derived from Kumho river, Nakdong river and around water. And the river management flow is estimated by addition of a use flow and a loss flow to more flow between a low-flow and an environmental preservation flow.

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