• 제목/요약/키워드: deterioration prediction

검색결과 225건 처리시간 0.038초

부산시 도심 노후화 진단에 관한 연구 (A Study of the Diagnosis of Downtown Deterioration in Busan)

  • 권일화;남광우
    • 한국지리정보학회지
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    • 제16권4호
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    • pp.39-53
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    • 2013
  • 효율적인 도시공간구조 형성은 에너지 절감 및 친환경적 측면에서 중요한 요소임에도 불구하고 핵심요소인 도심 및 부도심의 관리는 도시 활동의 변동성과 복잡성으로 인해 점차 어려워지고 있다. 부산의 경우 1960년 이후 도시의 급속한 경제성장으로 인한 도심 규모의 확대 및 인구과밀화 속에서 20년 단위의 도시기본계획 이외에 도심 기능에 대한 전문적인 진단이나 관리 등에 대한 체계적인 접근은 매우 부족하였다. 효율적인 도심지역의 관리를 위해서는 우선적으로 도심기능의 수요 및 노후 예측을 위한 체계적인 도심 모니터링이 필요하다. 이에 본 연구는 도심재생측면에서의 도심지역 노후 진단을 통해 현재 도심의 현황을 파악함과 동시에 향후 도심 관리를 위한 공간정보의 활용방안을 제시하고자 한다. 분석지표로는 물리적, 경제적, 사회적 지표로 나누어 현황을 살펴본 후, 미시적 접근으로 경제적 지표를 활용하여 부산시 서면 도심지역의 경제적 노후를 세부적으로 살펴보았다. 분석 결과 인구분포나 토지이용 측면에서 교외화 단계를 지나 비효율적 분산화 단계가 지속되고 있는 것으로 나타났다. 이는 도심 및 부도심의 기능 강화의 필요성을 의미하며 이에 본 연구는 보다 미시적 관점에서 도심지역을 진단하고 분석된 자료를 바탕으로 도심 지역의 문제점과 도심기능의 강화 방향을 제시하고자 한다.

무기질 항균제 도포에 의한 콘크리트의 경화성상 및 내구성상 향상에 관한 실험적 연구 (An Experimental Study on Development of Physical Properties and Durability of Concrete Spread with Inorganic Antibiotics)

  • 김무한;길배수;김재환;조봉석;이의배
    • 한국건축시공학회지
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    • 제5권3호
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    • pp.75-82
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    • 2005
  • Sewage facilities are positively necessary for environment improvement such as rainwater removal, sewage disposal, preservation of the quality of water and health of the citizens in present-day. Meanwhile, a deterioration of the concrete sewer pipe is increasing rapidly due to the chemical and physical attack and especially biochemical attack that is to say biodeterioration. So, in advanced countries, prediction techniques and corrosion inhibition system for sewer concrete are developed and are being applied. Also, antibiotics were developed already but application of that is low because it is not economical and has no practical use. But, in domestic, countermeasures for the corrosion of sewage concrete are not sufficient and biochemical attack is not reflected in those essentially. In this study, to prevent biochemical corrosion of the sewer concrete, surface of the concrete was spread with liquefied inorganic antibiotics and then its engineering properties were experimentally investigated. As a result, compressive strength of the specimen spread with antibiotics were similar to those of non spread, Both bond strength and abrasion amount of the specimen spread with antibiotics were inferior to non spread. Properties of absorption and air permeability of the specimen spread with antibiotics were superior to non spread. Finally, carbonation depth, chloride ion penetration depth and weight change ration of the specimen spread with antibiotics were smaller than non spread.

Engineering Geological Characteristics of Freeze-Thaw Weathered Gneiss in the Wonju Area, Korea

  • Um, Jeong-Gi;Woo, Ik;Park, Hyuck Jin
    • 지질공학
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    • 제24권2호
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    • pp.161-169
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    • 2014
  • We present the results of an experimental physical weathering study that focuses on fresh and slightly weathered gneiss samples from the Wonju area of Korea. The study investigated changes in the physico-mechanical properties of these samples during accelerated laboratory-based weathering, including analyses of microfracture formation. The deteriorated samples used in the study were subjected to 100-150 freeze-thaw cycles, with index properties and microfracture geometries measured between each cycle. Each complete freeze-thaw cycle lasted 24 hours, and consisted of 2 hours of saturation in a vacuum chamber, 8 hours of freezing at $-21^{\circ}C{\pm}1^{\circ}C$, and 14 hours of thawing at room temperature. Specific gravity and seismic velocity values were negatively correlated with the number of freeze-thaw cycles, whereas absorption values tended to increase. The amount of deterioration of the rock samples was dependent on the degree of weathering of the rock prior to the start of the analysis. Absorption, specific gravity, and seismic velocity values can be used to infer the amount of physical weathering experienced by a gneiss in the study area. The sizes and density of microfracture in the rock specimens varied with the number of freeze-thaw cycles. We found that box fractal dimensions can be used to quantify the formation and propagation of microfracture in the samples. In addition, these box fractal dimensions can be used as a weathering index for the mid-and long-term prediction of rock weathering. The present results indicate that accelerated-weathering analysis can provide a detailed overview of the weathering characteristics of deteriorated rocks.

계절 특성을 고려한 독성 피해예측에 따른 위기대응 고도화에 관한 연구 (A Study on the Advancement of the Contingency Plan upon Prediction of Toxicity Damage Considering Seasonal Characteristics)

  • 황만욱;황용우;이익모;민달기
    • 한국방재안전학회논문집
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    • 제9권2호
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    • pp.23-32
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    • 2016
  • 오늘날 주민 생활공간과 인접해 있는 산업단지의 노후화 문제는 지역사회 안전을 위협하는 원인으로 지적되고 있다. 본 연구에서는 현행의 위험도 분석 및 지역사회 고지범위를 제고하기 위해 대안의 사고시나리오의 영향범위와 계절별 기상 최빈값을 활용하여 모사된 영향범위를 비교 분석하였고, 시간대별로 관측된 풍향을 계절별로 검토하여 독성물질 누출 시 피해 가능성이 높은 지역을 예측하였다. 또한 인명피해를 최소화하기 위한 한계 대피시간 및 최소 이격거리를 제시하였으며, 비상대응에 활용되고 있는 위해관리계획서를 고찰하여 인근 근로자 및 주민에 대해 한층 더 합리적인 안전대책이 이루어질 수 있도록 제언하였다.

실공간 사용 공기조화기용 열교환기의 공기측 파울링 특성 예측 (Prediction of Characteristics for the Air-side Particulate Fouling in Finned-Tube Heat Exchangers of Air Conditioners used in the Field)

  • 안영철;정성학;황유진;이창건;김두현;정성일;이재근
    • 설비공학논문집
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    • 제19권8호
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    • pp.563-568
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    • 2007
  • The air-side particulate fouling in the heat exchangers of HVAC applications degrades the performances of cooling capacity, pressure drop across a heat exchanger, and indoor air quality. Indoor and outdoor air contaminants foul heat exchangers. An empirical modeling equation has been derived from the experimental results using accelerated tests and it showed good predictions of the fouling characteristics of the slitted finned tube heat exchangers. However the modeling equation predicts only the fouling characteristics of new heat exchangers and it can not predicts fouling characteristics obtained from actual field data which contains the effect of hydrophilicity deterioration. Therefore an modified modeling equation is proposed and it shows good predictions of the actual fouling characteristics of finned-tube heat exchangers.

도시계획과 환경영향평가 (Environmental Impact Assessment in Urban Planning)

  • 정용
    • 환경영향평가
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    • 제2권2호
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    • pp.1-11
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    • 1993
  • Most developing countries are experiencing rapid urbanization and the associated growth of industry and services. Cities are currently absorbing two-thirds of the total population in the developing world. Korea has about 85 percent of urban dwellers. World population will shift from being predominantly rural to predominantly urban around the turn of the century. Although cities play a key role in development process and make more than a proportionate contribution to national economic growth, especially cities are also the main catalysts of economic growth in developing countries, they can also be unhealthy, inefficient, and inequitable places to live. Most developing countries are increasingly unable to provide basic environmental infrastructure and services, whether in the megacities or in secondary urban centers. Of particular concern is the strain on natural resources brought by the increasing number of people, cars, and factories. They are generating ever greater amounts of urban wastes and emissions. They also exceed the capacity of regulatory authorities to control them and of nature to assimilate them. The environmental consequences are translated into direct negative impacts on human health, the quality of life, the productivity of the city, and the surrounding ecosystems. Environmental degradation threatens the long tenn availability and quality of natural resources critical to economic growth. Cities, with their higher and growing per capita energy use for domestic, industrial, and transport purpose also contribute a disproportionate share of the emission leading to global warming and acid rain. An important priority is to develop strategic approaches for managing the urban environment. The design of appropriate and lasting strategic responses requires first an understanding of the underlying causes of urban environmental deterioration, it is necessary that longer tenn objectives should be set for urban area to avoid irreversible ecological damage and to ensure lasting economic development. As a means to the preventive policies against the adverse effect, environmental impact assessment (EIA) serve to identify a project's possible environmental consequences early enough to allow their being taken into consideration in the decision making process for urban planning. This paper describes some considerations of EIA for urban planning-scoping, assessment process, measurement and prediction of impacts, pollution controls and supervision, and system planning for environmental preservation.

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고주파가열을 이용한 정어리 발포건조제품의 가공 II. 제품저장중의 품질변화와 저장기간 (Dehydration of foamed sardine-starch paste by microwave heating.)

  • 이병호
    • 기술사
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    • 제17권4호
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    • pp.8-14
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    • 1984
  • In this part of the studies on dielectric dehydration of foamed fish-starch paste, quality stability and shelflife of the product of which the preparation formula and processing conditions were described in the previous report (Lee et at., 1982) were determined by means of accelerated reaction test. The product was stored for 50 days under the conditions of temperatures at 35, 45, and 55$^{\circ}C$ in steady state and various water activities of 0.44, 0.52, 0.65, and 0.75, respectively. The loss of available lysine, the extent of TBA value, and the development of browning during the storage were measured and reaction kinetically analysed to assess quality stability and shelf-life of the product for the storage at room temperature of 25$^{\circ}C$. The extent of browning was accelerated with the increase of water activity and temperature marking the time to reach a limit of color and flavor deterioration, or to reach brown color density of 0.17 O.D./g at 420nm, 106 days at a$\_$w/=0.44, 35$^{\circ}C$, and 41 days at aw=0.65, 55$^{\circ}C$. These reaction rates resulted in a prediction of shelf-life, 130 to 110 days in the storage at au=0.44 to 0.75, 25$^{\circ}C$. The quality limit assessed by TBA values and sensory evaluation of rancidity was 87 days at a$\_$w/=0.44, 35$^{\circ}C$, and 30 days at aw=0.73, 55$^{\circ}C$ which gave a predicted shelf-life, 128 to 113 days at a$\_$w/=0.44 to 0.75, 25$^{\circ}C$ storage.

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H.264/AVC 비트스트림에서 썸네일 추출을 위한 새로운 방법 (A New Method for Thumbnail Extraction in H.264/AVC Bitstreams)

  • 홍승환;김지언;진영민;권재철;오승준
    • 방송공학회논문지
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    • 제15권6호
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    • pp.853-867
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    • 2010
  • IPTV, DMB 등과 같은 방통융합 기반 멀티미디어 서비스에서는 고성능 비디오 인덱싱을 위한 썸네일 기술이 요구되므로 H.264/AVC 비트스트림으로부터 직접 썸네일을 추출하는 방법이 제안되었다. 그러나 화소 공간에서 정의한 일반화 수식을 주파수 공간으로 변환하는 과정에서 H.264/AVC에 정의된 변환 및 양자화, 그리고 인트라 예측의 반올림을 고려하지 않음으로써 썸네일 화질을 저하시키는 문제점이 있다. 본 논문에서는 H.264/AVC 비트스트림에서의 새로운 썸네일 추출 방법을 제안한다. 제안하는 방법은 H.264/AVC 핵심 변환을 기반으로 주파수 공간에서의 썸네일 추출 방법을 이론적으로 정리하고 확률적 방법으로 인트라 예측의 반올림 보상 방법을 제시한다. 제안한 방법을 통해 얻은 썸네일은 참조 복호화기를 통해 얻은 썸네일과 주관적 화질은 크게 차이 나지 않으며 이전에 제안된 방법과 비교하여 주관적 화질 향상과 최대 8.66 dB의 PSNR 이득을 얻었다.

Survival-Related Factors of Spinal Metastasis with Hepatocellular Carcinoma in Current Surgical Treatment Modalities : A Single Institute Experience

  • Lee, Min Ho;Lee, Sun-Ho;Kim, Eun-Sang;Eoh, Whan;Chung, Sung-Soo;Lee, Chong-Suh
    • Journal of Korean Neurosurgical Society
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    • 제58권5호
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    • pp.448-453
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    • 2015
  • Objective : Recently, the survival of patients with hepatocellular carcinoma (HCC) has been prolonged with improvements in various diagnostic tools and medical treatment modalities. Consequently, spine metastases from HCC are being diagnosed more frequently. The accurate prediction of prognosis plays a critical role in determining a patient's treatment plan, including surgery for patients with spinal metastases of HCC. We investigated the clinical features, surgical outcomes, and prognostic factors of HCC presenting with spine metastases, in patients who underwent surgery. Methods : A retrospective review was conducted on 33 HCC patients who underwent 36 operations (three patients underwent surgical treatment twice) from February 2006 to December 2013. The median age of the patients was 56 years old (range, 28 to 71; male : female=30 : 3). Results : Overall survival was not correlated with age, sex, level of metastases, preoperative Child-Pugh classification, preoperative ambulatory function, preoperative radiotherapy, type of operation, administration of Sorafenib, or the Tokuhashi scoring system. Only the Tomita scoring system was shown to be an independent prognostic factor for overall survival. Comparing the Child-Pugh classification and ambulatory ability, there were no statistically differences between patients pre- and post-operatively. Conclusion : The Tomita scoring system represents a practicable and highly predictive prognostic tool. Even though surgical intervention may not restore ambulatory function, it should be considered to prevent deterioration of the patient's overall condition. Additionally, aggressive management may be needed if there is any ambulatory ability remaining.

제조 현장의 비정상 데이터 분류를 위한 기계학습 기반 접근 방안 연구 (Machine Learning based on Approach for Classification of Abnormal Data in Shop-floor)

  • 신현준;오창헌
    • 한국정보통신학회논문지
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    • 제21권11호
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    • pp.2037-2042
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    • 2017
  • 스마트 공장은 미리 입력된 프로그램에 의해 생산시설이 수동적으로 움직이는 공장 자동화 작업 방식과는 달리, 생산 설비 스스로 작업 방식을 결정하여야 한다. 생산 설비 스스로 작업 방식을 결정이라 함은, 이를테면 제조 현장에서 설비의 노후, 문제 발생 예측, 제품의 불량 검출 등과 같은 이상 징후가 발생할 시 이를 조기에 발견한 후 스스로 문제를 해결하는 것을 의미한다. 본 논문에서는 제조 현장의 제조 공정 이상 징후 감지를 위해 대기행렬을 이용한 제조 공정 모델링을 제시하고 해당 모델링에서 이상 징후를 기계학습 기술 중 하나인 SVM을 이용하여 이를 감지하도록 한다. 해당 대기행렬을 M/D/1을 사용하였으며, ${\mu}$, ${\lambda}$, ${\rho}$를 기반으로 컨베이어 벨트 제조 시스템을 모델링하였다. SVM을 이용하여 ${\rho}$의 변화량을 통해 이상 징후를 감지했다.