• 제목/요약/키워드: FNR process

검색결과 11건 처리시간 0.026초

FNR process를 이용한 하수처리장의 질소.인의 제거에 관한 연구 (A Study on Nitrogen and Phosphorus Removal in FNR Process)

  • 조일형;이내현;이승목;김영규
    • 한국환경과학회지
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    • 제15권6호
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    • pp.571-577
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    • 2006
  • This study make a comparison between the phosphorus removal performance of FNR(Ferrous Nutrient Removal) process and A/O process by the laboratory experiments. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. Iron precipitation reactor on the electrochemical behaviors of phosphorus in the iron bed. The phosphorus removal in FNR process was more than A/O process. Iron salts produced by iron electrolysis might help to remove COD and nitrogen. And the demanded longer SRT is the more removes the removes COD, nitrogen, and phosphorus. Also, FNR process of sludge quantity more reduce than A/O process to input cohesive agents.

철전기분해장치(FNR)에서 철판의 표면적이 인제거에 미친 영향에 관한 연구 (A Study on Phosphorus Removal Effects Per Iron Surface Area in FNR Process)

  • 김영규
    • 한국환경보건학회지
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    • 제38권6호
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    • pp.568-574
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    • 2012
  • Objectives: The purpose of this experiment is to understand the phosphorus removal ratio effects of iron plates per unit of surface area through the iron electrolysis system, which consists of an anoxic basin, aerobic basin, and iron precipitation apparatus. Methods: Iron electrolysis, which uses an iron precipitation reactor in anoxic and oxic basins, consisted of iron plates with total areas of 400 $cm^2$, 300 $cm^2$ and 200 $cm^2$ respectively. The FNR process was operated with a hydraulic retention time and a sludge retention time of 12 hours and three days, respectively. Wastewater used in the experiments was prepared by dissolving $KH_2PO_4$ in influent water. Results: The iron plates 400 $cm^2$ (16.6 $mA/cm^2$), 300 $cm^2$ (13.3 $mA/cm^2$) and 200 $cm^2$ (7.3 $mA/cm^2$) in surface area in the phosphorus reactor had respective phosphorus of 2.4 mg/l, 2.7 mg/l and 3.2 mg/l in the effluent and phosphorus removal respective efficiencies of 90.3%, 89.1% and 87.1%. The effluent in the reactor, where the iron plate was not used, had relatively very low phosphorus removal efficiency showing phosphorus concentration of 15.3 mg/l and a phosphorus removal efficiency about 38.3%. Phosphorus removal per ferrous was 0.472 mgP/mgFe in the iron electrolysis system where the surface area of iron was low. Phosphorus pollution load per active surface area and the phosphorus removal efficiency had an interrelation of RE = -0.27LS + 89.0 (r = 0.85). Conclusion: With larger iron plate surface area, the elution of iron concentration and phosphorus removal efficiency was higher. The removal efficiency of phosphorus has decreased by increasing the initial phosphate concentration in the iron electrodes. This shows a tendency of decreasing phosphorus removal efficiency because of decreasing of iron deposition as the phosphorus pollution load per active surface area increases.

GCNXSS: An Attack Detection Approach for Cross-Site Scripting Based on Graph Convolutional Networks

  • Pan, Hongyu;Fang, Yong;Huang, Cheng;Guo, Wenbo;Wan, Xuelin
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제16권12호
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    • pp.4008-4023
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    • 2022
  • Since machine learning was introduced into cross-site scripting (XSS) attack detection, many researchers have conducted related studies and achieved significant results, such as saving time and labor costs by not maintaining a rule database, which is required by traditional XSS attack detection methods. However, this topic came across some problems, such as poor generalization ability, significant false negative rate (FNR) and false positive rate (FPR). Moreover, the automatic clustering property of graph convolutional networks (GCN) has attracted the attention of researchers. In the field of natural language process (NLP), the results of graph embedding based on GCN are automatically clustered in space without any training, which means that text data can be classified just by the embedding process based on GCN. Previously, other methods required training with the help of labeled data after embedding to complete data classification. With the help of the GCN auto-clustering feature and labeled data, this research proposes an approach to detect XSS attacks (called GCNXSS) to mine the dependencies between the units that constitute an XSS payload. First, GCNXSS transforms a URL into a word homogeneous graph based on word co-occurrence relationships. Then, GCNXSS inputs the graph into the GCN model for graph embedding and gets the classification results. Experimental results show that GCNXSS achieved successful results with accuracy, precision, recall, F1-score, FNR, FPR, and predicted time scores of 99.97%, 99.75%, 99.97%, 99.86%, 0.03%, 0.03%, and 0.0461ms. Compared with existing methods, GCNXSS has a lower FNR and FPR with stronger generalization ability.

철 석출장치에 의한 폐수 중의 인 제거 특성 (Characterization of Phosphorus Removal in Wastewater Using Iron Precipitation Reactor)

  • 조일형;조경덕;안상우;장순웅;김영규
    • 한국환경보건학회지
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    • 제32권1호
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    • pp.89-95
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    • 2006
  • This study was conducted to improve an effect of phosphorus removal using FNR(Ferrous Nutrient Removal) process which had iron precipitation reactor and to analyze the iron corrosion. For simultaneous removal of phosphorus, iron electrolysis was combined with oxic tank. In this study, The removal efficiency of phosphorus increased with an increase voltage in iron precipitation reactor. The distance of 15mm between the two iron bed in each tests influence the concentration of remaining phosphorus most. The extensive surface area of iron bed is the more removes the phosphorus. In this test the $400\;cm^2$ of surface area was proved to be the most removal efficient.

새만금 담수 활용을 위한 요구수질별 최적의 수처리 방안 연구 (Design of Optimal Water Treatment Processes based on Required Water Quality for Utilization of the Saemanguem Lake Water)

  • 최경숙;이광야
    • 농업생명과학연구
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    • 제46권2호
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    • pp.169-178
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    • 2012
  • 새만금 지역의 담수수자원의 활용과 고부가가치 창출을 위해 새만금 담수호를 활용한 요구수질별 용수공급을 위한 최적의 수처리 시스템을 선정하고 이에 대한 비용분석을 통해 요구수질별 담수수자원의 활용방안을 제시하고자 하였다. 다양한 수처리 기법들의 종류, 주요 특성 및 오염인자 제거효율, 공법의 장단점 등의 비교분석을 통해 수질오염인자별 유리한 처리공법을 제시하였으며, 최적의 수처리시스템을 도출하여 새만금 지역 내 요구수질별 수처리 비용을 분석하였다. 연구결과를 통해 SS(Suspended Solid), BOD(Biochemical Oxygen Demand), 탁도 제거를 위해 FDA(Filter Disinfection Adsorption)여과기, 대장균 제거를 위한 UV(Ultra-Violet)처리공정, T-P(Total Phosphorus), T-N(Total Nitrogen) 제거를 위한 FNR(Ferrous Nutrient Removal)공법, 그리고 저농도 염처리 공정을 위해 전기투석법이 유리한 공법으로 조사되어 최적의 수처리시스템의 요소기술로 각각 선정되었다. 각 요구수질별 선정된 수처리공정에 따른 비용분석과 적용사례를 제시하여 새만금지역 담수 활용도를 높이고 부족한 상수원 해결의 대안으로 적용할 수 있을 것으로 사료된다.

기하학적 텍스쳐 정보를 이용한 금속 패드 변색영상 분류 알고리즘 (Metal pad Discolored Image Classification Algorithm using Geometric Texture Information)

  • 최학남;김학일
    • 제어로봇시스템학회논문지
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    • 제16권5호
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    • pp.469-475
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    • 2010
  • This paper presents a method of classifying discolored defects of metal pads using geometric texture for AFVI (Automated Final Vision Inspection) systems. In PCB manufacturing process, the metal pads on PCB can be oxidized and discolored partly due to various environmental factors. Nowadays the discolored defects are manually detected and rejected from the process. This paper proposes an efficient geometric texture feature, SUTF (Symmetry and Uniformity Texture Feature) based on the symmetric and uniform textural characteristics of the surface of circular metal pads for automating AFVI systems. In practical experiments with real samples acquired from a production line, 30 discolored images and 1232 roughness images are tested. The experimental results demonstrate that the proposed method using SUTFs provides better performance compared to Gabor feature with 0% FNR (False Negative Rate) and 1.46% FPR (False Positive Rate). The performance of the proposed method shows its applicability in the real manufacturing systems.

철전기분해장치(FNR)에서 단위공정에 따른 질소와 인의 제거 (A Study on Phosphorus and Nitrogen Removal with Unit Operation in the Ferrous Nutrient Removal Process)

  • 김수복;김영규
    • 한국환경보건학회지
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    • 제39권1호
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    • pp.83-89
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    • 2013
  • Objectives: The purpose of this experiment was to illuminate the relationship between the phosphorus removal rate of unit operation and the phosphorus removal rate of phosphorus volume loading in the Ferrous Nutrient Removal process, which consists of an anoxic basin, oxic basin, and iron precipitation apparatus. Methods: This study was conducted in order to improve the effect of nitrogen and phosphorus removal in domestic wastewater using the FNR (Ferrous Nutrient Removal) process which features an iron precipitation reactor in anoxic and oxic basins. The average concentration of TN and TP was analyzed in a pilot plant ($50m^3/day$). Results: The removal rate of T-N and T-P were 66.5% and 92.8%, respectively. The $NH_3-N$ concentration of effluent was 2.62 mg/l with nitrification in the oxic basin even though the influent was 17.7 mg/l. The $NO_3$-N concentration of effluent was 5.83 mg/l through nitrification in oxic basin even though the influent and anoxic basin were 0.82 mg/l and 1.00 mg/l, respectively. The specific nitrification of the oxic basin ($mg.NH_3$-Nremoved/gMLVSSd) was 16.5 and specific de-nitrification ($mg.NO_3$-Nremoved/gMLVSSd) was 90.8. The T-P removal rate was higher in the oxic basin as T-P of influent was consumed at a rate of 56.3% in the anoxic basin but at 90.3% in the oxic basin. The TP removal rate (mg.TP/g.MLSS.d) ranged from 2.01 to 4.67 (3.06) as the volume loading of T-P was increased, Conclusions: The test results showed that the electrolysis of iron is an effective method of phosphorus removal. Regardless of the temperature and organic matter content of the influent, the quality of phosphorus in the treated water was both relatively stable and high due to the high removal efficiency. Nitrogen removal efficiency was 66.5% because organic matter from the influent serves as a carbon source in the anoxic basin.

Sentinel Node Biopsy Examination for Breast Cancer in a Routine Laboratory Practice: Results of a Pilot Study

  • Khoo, Joon-Joon;Ng, Chen-Siew;Sabaratnam, Subathra;Arulanantham, Sarojah
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권3호
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    • pp.1149-1155
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    • 2016
  • Background: Examination of sentinel lymph node (SLN) biopsies provides accurate nodal staging for breast cancer and plays a key role in patient management. Procurement of SLNs and the methods used to process specimens are equally important. Increasing the level of detail in histopathological examination of SLNs increases detection of metastatic tumours but will also increase the burden of busy laboratories and thus may not be carried out routinely. Recommendation of a reasonable standard in SLN examination is required to ensure high sensitivity of results while maintaining a manageable practice workload. Materials and Methods: Twenty-four patients with clinically node-negative breast cancer were recruited. Combined radiotracer and blue dye methods were used for identification of SLNs. The nodes were thinly sliced and embedded. Serial sectioning and immunohistochemical (IHC) staining against AE1/AE3 were performed if initial H&E sections of the blocks were negative. Results: SLNs were successfully identified in all patients. Ten cases had nodal metastases with 7 detected in SLNs and 3 detected only in axillary nodes (false negative rate, FNR=30%). Some 5 out of 7 metastatic lesions in the SLNs (71.4%) were detected in initial sections of the thinly sliced tissue. Serial sectioning detected the remaining two cases with either micrometastases or isolated tumour cells (ITC). Conclusions: Thin slicing of tissue to 3-5mm thickness and serial sectioning improved the detection of micro and macro-metastases but the additional burden of serial sectioning gave low yield of micrometastases or ITC and may not be cost effective. IHC validation did not further increase sensitivity of detection. Therefore its use should only be limited to confirmation of suspicious lesions. False negative cases where SLNs were not involved could be due to skipped metastases to non-sentinel nodes or poor technique during procurement, resulting in missed detection of actual SLNs.

극장 판 장편 애니메이션의 시각적 스타일에 관한 연구 -장편애니메이션 'Life is Cool'의 제작사례를 중심으로- (A Study for Visual Style for Feature Animation - A Case of Feature Animation -)

  • 최승원
    • 방송공학회논문지
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    • 제12권5호
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    • pp.391-400
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    • 2007
  • 애니메이션을 제작함에 있어 표현에 대한 방식은 실로 무궁무진하며 그것이야말로 실사영화에서는 볼 수 없는 애니메이션만이 가진 표현의 강점이며 관객들에게 어필할 수 있는 최대의 무기중 하나이다. 그럼에도 불구하고 극장 상영을 위한 장편 애니메이션을 제작함에 있어서 제작자들에게 선택되어온 제작기법은 Drawing, 3D Computer, Clay등과 같이 지극히 획일적이다. 상업적인 목적을 가지고 제작된 애니메이션은 시각적인 스타일면에서 대중성을 확보해야 하지만 표현성에서 대중적이라 함은 획일화되어 있는 스타일과 제작기법을 의미하는 것은 아니며 대중을 매료시킬 수 있는 예술성이라는 측면에서 이해되어야 한다. 관객은 항상 새로운 소재, 새로운 연출, 새로운 시각적 스타일을 원한다. 천편일률적으로 파일화 된 애니메이션은 관객들에게 외면 당 할 수밖에 없을 것이다 따라서 상업적인 목적으로 기획, 제작되어진 애니메이션이라 할지라도 작품자체가 예술적 가치를 지니고 있지 못한다면 가시적인 상업적 가치 또한 기대하기 어렵다. 애니메이션을 제작하기 위해 시각적 스타일을 디자인한다는 것은 아트워크 자체에 국한되는 문제가 아니며 작품의 내용과 분위기 그리고 캐릭터가 반영된 움직임의 스타일까지 포함되는 디자인이어야 한다. 여기에 더해 완성된 디자인을 제작적인 측면에서 실현할 수 있도록 제작 프로세스 또한 치밀하게 계산되고 실험되어야 한다.