• Title/Summary/Keyword: 수명단축

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An Energy Efficient Continuous Skyline Query Processing Method in Wireless Sensor Networks (무선 센서 네트워크 환경에서 에너지 효율적인 연속 스카이라인 질의 처리기법)

  • Seong, Dong-Ook;Yeo, Myung-Ho;Yoo, Jae-Soo
    • Journal of KIISE:Computing Practices and Letters
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    • v.15 no.4
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    • pp.289-293
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    • 2009
  • In sensor networks, many methods have been proposed to process in-network aggregation effectively. Contrary to normal aggregation queries, skyline query processing that compare multi-dimension data for producing result is very hard. It is important to filter unnecessary data for energy-efficient skyline query processing. Existing approach like MFTAC restricts unnecessary data transitions by deploying filters to whole sensors. However, network lifetime is reduced by energy consumption for filters transmission. In this paper, we propose a lazy filtering-based skyline query processing algorithm of in-network for reducing energy consumption by filters transmission. The proposed algorithm creates the skyline filter table (SFT) in the data gathering process which sends from sensor nodes to the base station and filters out unnecessary transmissions using it. The experimental results show that the proposed algorithm reduces false positive by 53% and improves network lifetime by 44% on average over MFTAC.

In situ iron/manganese removal and permeability improvement at the river bank filtration site (강변여과수내 철망간 저감 및 투수성 개선)

  • Kim, Byung-Woo;Kim, Byung-Goon;Hur, Young-Teck;Kim, Dong-Sup;Kim, Hong-Suck
    • Proceedings of the Korea Water Resources Association Conference
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    • 2018.05a
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    • pp.228-228
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    • 2018
  • 강변여과는 지하수 인공함양 방식 중 유도함양(induced recharge) 또는 간접함양 방식에 속한다. 이는 하천 및 강변 부근에 집수시설을 설치한 후, 미고결층 대수층(unconsolidated aquifer)의 자연 오염 저감능을 이용하여 지표수를 간접 취수하는 방식으로 수질이 불량한 지표수가 대수층을 관류하면서 희석, 화학적 이온 교환 및 반응, 흡착, 생물막(biofilm; 미생물에 의한 자연저감), 여과 등을 통하여 수질이 개선된다. 강변여과수내의 용존 농도가 높은 철과 망간은 수처리 비용증가, 용수관정 및 시설물의 수명단축을 초래한다. 따라서 강변여과 지역의 미고결 대수층에서 효과적인 철과 망간 동시 제거(vyredox)를 위해 에어서징(air surging)과 블록 서징(block surging)을 실시하기 위해서 실내 물탱크 모델(water tank model)에서 에어서징에 따른 공기 순환 우물시스템을 관찰하였으며, 이를 바탕으로 현장시험(Test bed)에 적용하였다. 미고결 대층수층에서의 철 망간은 음용수 기준치(각각 0.3 mg/L)를 초과하고 있으며, 강변여과 취수 개발 및 이용을 제한하는 요인이 되고 있다. 본 연구에서 사용된 에어서징과 블록서지 기술은 자갈층 및 미고결 대수층에 충진된 슬라임 및 폐색(clogging)을 제거함과 동시에 관정 주변의 대수층의 투수성 개선과 산화환경으로 치환되며, 대수층에 잔존하는 철/망간의 산화물들을 관정내로 빼낼 수 있는 방법이다. 따라서 서징에 따른 폐색 제거효율을 검토한 결과에서 철 망간 이온농도 저감효과와 관정 주변의 수리전도도(hydraulic conductivity) 및 저류계수(coefficient of storage)가 증가한 것으로 나타났다. 이와 같이 강변여과에 의한 폐색은 미고결층내 공기주입 및 블록서지를 통하여 철/망간 이온농도 저감 및 수리특성 개선 효과에 유용한 것으로 평가된다.

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A Sextant Cluster Based Monitoring on Secure Data Aggregation and Filtering False Data in Wireless Sensor Networks (무선센서 네트워크에서의 육분원 방식 모니터링 기반 안전한 데이터 병합 및 위조 데이터 필터링)

  • Boonsongsrikul, Anuparp;Park, Seung-Kyu;Shin, Seung-Hun
    • Journal of the Korea Society of Computer and Information
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    • v.17 no.2
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    • pp.119-126
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    • 2012
  • Local monitoring is an effective technique in securing data of wireless sensor networks. Existing solutions require high communication cost for detecting false data and this results in a network lifetime being shortened. This paper proposes novel techniques of monitoring based secure data aggregation and filtering false data in wireless sensor networks. The aim is to reduce energy consumption in securing data aggregation. An aggregator and its monitoring node perform data aggregation in a 60o sextant cluster. By checking Message Authentication Codes (MAC), aggregation data will be dropped by a forward aggregator if data aggregated by the aggregator and data monitored by the monitoring node are inconsistent. The simulation shows that the proposed protocol can reduce the amount of average energy consumption about 64% when comparing with the Data Aggregation and Authentication protocol (DAA)[1]. Additionally, the network lifetime of the proposed protocol is 283% longer than that of DAA without any decline in data integrity.

Analysis of the Driving & Loading Pattern of the Construction Waste Collecting Trucks Using IoT On-Board Truck Scale System (IoT 자중계 시스템을 활용한 건설폐기물 수집·운반 차량의 운행 및 적재패턴 분석)

  • Kim, Jong Woo;Jung, Young Woo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.6
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    • pp.74-87
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    • 2020
  • Overloaded trucks are the main source that threatens road safety and directly affects the reduction of pavement life. The On-board truck scale is the only equipment that could prevent overloading by measuring and adjusting the loading weight before driving. Legislation is needed to encourage its installation so that the driver can prevent overloading. In this study, an on-board truck scale system was installed on 30 dump trucks for transporting construction waste, such as soil and aggregates, which are major loads of 36.55% for overloading, and the trucks were monitored remotely. The overload prevention effect was analyzed by comparing driving data for 1 month before distribution of the weight display app that can recognize the weight to the driver and 1 month after distribution. After installation, overloading could be 6.1% reduced, and the transportation efficiency could be increased by checking the weight provided from the On-board truck scale system.

A Study on Modification of Industrial Accident Indicator Considering Working Environment Change (근로 환경 변화를 고려한 산업재해지표 수정 방안에 관한 연구)

  • Eum, Tae Soo;Shin, Eun Taek;Song, Chang Geun
    • Journal of Korean Society of Disaster and Security
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    • v.14 no.4
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    • pp.1-7
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    • 2021
  • Although the working environment has changed significantly compared to the past, such as the implementation of the five-day work week and the aging of the population, it is not reflected in the current industrial accident index calculation such as frequency rate, severity rate, and safe T-score. In this study, statistical data were used to understand time-series trends such as increase in life expectancy, working age, shortening of working hours, and average age of death by accident. As a result of time series trend analysis of statistical data, life expectancy increased to 83.3 years, and the legal working age was raised to 65 years due to the aging of the population. Also, with the advent of the 5-day work week since 2001, the average annual working hours decreased to 2008.1 hours. It can be confirmed through statistical data that these phenomena are applied to the current working environment due to a complex action, and these environmental changes affect the calculation results of the industrial accident index.

A study of Battery User Pattern Change tracking method using Linear Regression and ARIMA Model (선형회귀 및 ARIMA 모델을 이용한 배터리 사용자 패턴 변화 추적 연구)

  • Park, Jong-Yong;Yoo, Min-Hyeok;Nho, Tae-Min;Shin, Dae-Kyeon;Kim, Seong-Kweon
    • The Journal of the Korea institute of electronic communication sciences
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    • v.17 no.3
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    • pp.423-432
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    • 2022
  • This paper addresses the safety concern that the SOH of batteries in electric vehicles decreases sharply when drivers change or their driving patterns change. Such a change can overload the battery, reduce the battery life, and induce safety issues. This paper aims to present the SOH as the changes on a dashboard of an electric vehicle in real-time in response to user pattern changes. As part of the training process I used battery data among the datasets provided by NASA, and built models incorporating linear regression and ARIMA, and predicted new battery data that contained user changes based on previously trained models. Therefore, as a result of the prediction, the linear regression is better at predicting some changes in SOH based on the user's pattern change if we have more battery datasets with a wide range of independent values. The ARIMA model can be used if we only have battery datasets with SOH data.

A Study on the Benefits of PLM system baed on Data Integration and Process Management (PLM 시스템 기반의 데이터통합 및 프로세스관리가 경영성과에 미치는 영향에 관한 연구)

  • Kim, Kap-San;Han, Kyeong-Seok;Huh, Ho-Won
    • Journal of Digital Convergence
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    • v.10 no.6
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    • pp.133-140
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    • 2012
  • This study starts from interests on an endeavor of each economy unit, especially the enterprises, for the survival and sustainability of themselves. Competition, how to get it, maintain it and advance it! Agreeing the perceivedness of industries, scholars and public; what the core competition of manufacturer is an competitiveness of product, this study focuses on the PLM system as the key solution for obtaining the competitiveness of product with reviewing the contents and studies of PLM formulated. PLM is highlighted as the one of top tier ICT solution for the product development domain of manufacturing industry today. First of all, this study deals with the opinion of actual work-site and management of our small&medium business for the benefits of PLM based on product development; the impact on the performances of management, which is the key objective of the existence of enterprises. In conclusion, the answers for these questionnaires shows positive perception of actual work-sites and managers for the PLM system. They agree some useful effects on shortening the term and downsizing the cost of product development due to Data integration and Process management, even if they have not full confidence on the effectiveness of the individual functionality of the PLM system.

Effects of Fumigation Methods on Insect Disinfestation and Quality of Cut Rose and Lily (훈증방법이 살충력 및 절화장미·백합의 품질에 미치는 영향)

  • Son, Ki-Cheol;Byoun, Hye-Jin;Kim, Mi-Kyoung;Yun, Jae Gil;Chung, Soon-Kyung
    • Horticultural Science & Technology
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    • v.16 no.3
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    • pp.374-376
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    • 1998
  • Effects of traditional fumigation (methyl bromide; MB) and combined fumigation (methyl bromide/phosphide; $MB/PH_3$) on the disinfestation, and phytotoxicity and longevity of cut flowers (lily and rose) were investigated. Combined fumigation with low concentrations of $7/3g/m^3\;(MB/PH_3$) at $10^{\circ}C$ immediately after transportation from harvested place was found to be much more effective in disinfestation of aphid, mite, and thrips than fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days. Quality and longevity of cut flowers measured after fumigation were better in flowers treated by combined fumigation ($7/3g/m^3,\;MB/PH_3$) at $10^{\circ}C$ for 2.5-3 hrs, irrespective of pretreatment with pulsing solution immediately after transporation, even though phytotoxicity varied with cut flowers fumigated. On the other hand, fumigation with $MB\;48g/m^3$ only at $20^{\circ}C$ after simulated transportation for 2 days showed tendency of enhanced insect disinfestation, but caused phytotoxicity to both lily and rose, regardless of pretreatment and moreover, reduced the longevity of the cut flowers.

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Prediction of Life Time of Ion-exchange Membranes in Vanadium Redox Flow Battery (바나듐 레독스 흐름전지용 이온교환막의 수명 예측)

  • Cho, Kook-Jin;Park, Jin-Soo
    • Journal of the Korean Electrochemical Society
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    • v.19 no.1
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    • pp.14-20
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    • 2016
  • Vanadium redox flow battery (VRFB) is an energy conversion device in which charging and discharging are alternatively carried out by oxidation and reduction reactions of vanadium ions with different oxidation states. VRFB consists of electrolyte, electrode, ion-exchange membrane, etc. The role of ion-exchange membranes in VRFB separates anolyte and catholyte and provides a high conductivity to hydrogen ions. Recently much attention has been devoted to develop ideal ion-exchange membranes for VRFB. A number of developed ion-exchange membranes should be evaluated to find out ideal ion-exchange membranes for VRFB. Long-term durability test is a crucial characterization of ion-exchange membranes for commercialization, but is very time-consuming. In this study, the life time prediction protocol of ion-exchange membranes in VRFB cell tests was developed through short-term single cell performance evaluation (real total operation time, 87.5 hrs) at three different current densities. We confirmed a decrease in test time up to 96.2% of real durability tests (expected total operation time, 2,296 hrs) and 5~6% of relative error discrepancy between the predicted and the real life time in a unit cell.

Analysis on the Relationship of MOT and NPD Performance -Medium-Sized Manufacturing Firms- (기술경영과 신제품개발 성과와의 관계분석 -중규모 제조기업을 중심으로-)

  • Park, Chul Min
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.7 no.4
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    • pp.159-168
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    • 2012
  • The purpose of this study is to analyze the relationship of MOT and NPD performance in medium-sized manufacturing firms. To accomplish the purpose of the study, working hypotheses were established based on the literatures about the impacts of MOT factors on the NPD performance. The sample of this study is as follows : 12 electrical and electronics companies, 18 machine and engineering companies, 16 parts and materials companies. In order to verify hypotheses, the data were collected from team leader and manager of research center, R&D, and production department of these companies and the leader of R&D project team who all had experience in project or were participating in it in latest 3 years. The results of study were summarized as follows : First, in analysis on the reality of MOT factors in sample firms, will of top management level on the MOT was comparatively high but relatedness of business strategy and technology strategy, open R&D system, systematic time scheduling, management of R&D manpower, and developing and adapting PLM system were common level. Second, to improve NPD performance in medium-sized manufacturing firms, will of top management level on the MOT, relatedness of business strategy and technology strategy, open R&D system, systematic time scheduling, management of R&D manpower, and developing and adapting PLM system were intensively required.

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