• 제목/요약/키워드: granulation

검색결과 451건 처리시간 0.031초

Multi-FNN Identification Based on HCM Clustering and Evolutionary Fuzzy Granulation

  • Park, Ho-Sung;Oh, Sung-Kwun
    • International Journal of Control, Automation, and Systems
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    • 제1권2호
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    • pp.194-202
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    • 2003
  • In this paper, we introduce a category of Multi-FNN (Fuzzy-Neural Networks) models, analyze the underlying architectures and propose a comprehensive identification framework. The proposed Multi-FNNs dwell on a concept of fuzzy rule-based FNNs based on HCM clustering and evolutionary fuzzy granulation, and exploit linear inference being treated as a generic inference mechanism. By this nature, this FNN model is geared toward capturing relationships between information granules known as fuzzy sets. The form of the information granules themselves (in particular their distribution and a type of membership function) becomes an important design feature of the FNN model contributing to its structural as well as parametric optimization. The identification environment uses clustering techniques (Hard C - Means, HCM) and exploits genetic optimization as a vehicle of global optimization. The global optimization is augmented by more refined gradient-based learning mechanisms such as standard back-propagation. The HCM algorithm, whose role is to carry out preprocessing of the process data for system modeling, is utilized to determine the structure of Multi-FNNs. The detailed parameters of the Multi-FNN (such as apexes of membership functions, learning rates and momentum coefficients) are adjusted using genetic algorithms. An aggregate performance index with a weighting factor is proposed in order to achieve a sound balance between approximation and generalization (predictive) abilities of the model. To evaluate the performance of the proposed model, two numeric data sets are experimented with. One is the numerical data coming from a description of a certain nonlinear function and the other is NOx emission process data from a gas turbine power plant.

Identification of Fuzzy Inference System Based on Information Granulation

  • Huang, Wei;Ding, Lixin;Oh, Sung-Kwun;Jeong, Chang-Won;Joo, Su-Chong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제4권4호
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    • pp.575-594
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    • 2010
  • In this study, we propose a space search algorithm (SSA) and then introduce a hybrid optimization of fuzzy inference systems based on SSA and information granulation (IG). In comparison with "conventional" evolutionary algorithms (such as PSO), SSA leads no.t only to better search performance to find global optimization but is also more computationally effective when dealing with the optimization of the fuzzy models. In the hybrid optimization of fuzzy inference system, SSA is exploited to carry out the parametric optimization of the fuzzy model as well as to realize its structural optimization. IG realized with the aid of C-Means clustering helps determine the initial values of the apex parameters of the membership function of fuzzy model. The overall hybrid identification of fuzzy inference systems comes in the form of two optimization mechanisms: structure identification (such as the number of input variables to be used, a specific subset of input variables, the number of membership functions, and polyno.mial type) and parameter identification (viz. the apexes of membership function). The structure identification is developed by SSA and C-Means while the parameter estimation is realized via SSA and a standard least square method. The evaluation of the performance of the proposed model was carried out by using four representative numerical examples such as No.n-linear function, gas furnace, NO.x emission process data, and Mackey-Glass time series. A comparative study of SSA and PSO demonstrates that SSA leads to improved performance both in terms of the quality of the model and the computing time required. The proposed model is also contrasted with the quality of some "conventional" fuzzy models already encountered in the literature.

하지의 난치성 창상치유에 있어 VAC(Vacuum-Assisted Closure)의 유용성 (The Efficiency of VAC(Vacuum-Assisted Closure) in Non-healing Wound)

  • 박정민;권용석;정기환;이근철;김석권;안원석
    • Archives of Plastic Surgery
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    • 제32권6호
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    • pp.727-732
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    • 2005
  • The treatment of wounds of the lower extremity caused by diabetes or vascular dysfunction remains a difficult problem for the plastic surgeon. The use of negative pressure in wound healing is a relatively new method to facilitate chronic wound healing by secondary healing. The use of vacuum-assisted closure(VAC) system is purposed to reduce local edema, increase regional blood flow, enhance epithelial migration, preserve a moist wound environment, reduce bacterial colonization, promote granulation tissue formation, and mechanically enhance wound closure. The VAC also can be used as a dressing for anchoring an applied split thickness skin graft. We reviewed the data from 20 consecutive patients with non-healing wound in lower extremity at Dong-A University from March 2002 to December 2004. We used the VAC in 20 patients and compared the results with the control group. In the VAC using group, mean application duration was about 3 weeks and dressing change was done every other day. The follow-up period of patients ranged from 3 months to 30 months with a mean of 17 months. The points of comparison with control group are wound size, granulation tissue proliferation rate, operation method, preoperative time, postoperative healing time, complication, and cost. With those points, we propose to approve the efficiency of the VAC in non-healing wound. As a result, the VAC used in non-healing wound decrease wound size, accelerate granulation tissue formation, do a wound closure with less invasive operation method, make less postoperative complication, can make operation time shorter. Therefore it is cost effect. Our results demonstrate the usefulness of VAC as an adjunct in management of chronic wounds with other extrinsic factors.

Effect of Solvents on Physical Properties and Release Characteristics of Monolithic Hydroxypropylmethylcellulose Matrix Granules and Tablets

  • Cao Qing-Ri;Choi Yun-Woong;Cui Jing-Hao;Lee Beom-Jin
    • Archives of Pharmacal Research
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    • 제28권4호
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    • pp.493-501
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    • 2005
  • Effect of solvents on physical characteristics and release characteristics of monolithic acetaminophen (APAP) hydroxypropylmethylcellulose (HPMC) matrix granules and tablets were examined. Various types and amounts of solvents were employed for granulation and coating. APAP and other excipients were mixed and were then wet-granulated in a high-speed mixer. The dried granules were then directly compressed and film-coated with low viscosity grade HPMC. As the amount of water increased, the size of granules also increased, showing more spherical and regular shape. However, manufacturing problems such as capping and lamination in tableting occurred when water was used alone as a granulating solvent. The physical properties of HPMC matrix granules were not affected by the batch size. The initial release rate as well as the amount of APAP dissolved had a tendency to decrease as the water level increased. Addition of nonaqueous solvent like ethanol to water resulted in good physical properties of granules. When compared to water/ethanol as a coating solvent, the release rate of film-coated HPMC matrix tablets was more sensitive to the conditions of coating and drying in methylene chloride/ethanol. Most of all, monolithic HPMC matrix tablet when granulated in ethanol/water showed dual release with about $50\%$ drug release immediately within few minutes followed by extended release. It was evident that the type and amount of solvents (mainly water and ethanol) were very important for wet granulation and film-coating of monolithic HPMC matrix tablet, because the plastic deforming and fragmenting properties of material were changed by the different strengths of the different solvents.

광물질(鑛物質)의 종류(種類) 및 입도(粒度)가 황산가리(黃酸加理) 조립(造粒)에 미치는 영향(影響) (The Influence of Fillers (Zeolite, Serpentine and Talc) and their Fineness on Granulation of Sulfate of Potash)

  • 이윤환;이인수
    • 한국토양비료학회지
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    • 제15권3호
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    • pp.188-193
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    • 1982
  • 분말황산가리(粉末黃酸加里)와 입도(粒度)를 달리한 수종의 광물분말(제오라이트, 활석(滑石), 사문석(蛇紋石))을 혼합(混合) 또는 피복(被覆) 조입(造粒)하여 그 조입율(造粒率)과 물리적(物理的)인 특징(特徵)을 조사(調査)한 결과(結果) 3종(種) 광물 공(共)히 조입율(造粒率)을 향상(向上)시켰으며 활석(滑石), 제오라이트 사문석(蛇紋石) 순(順)으로 조입율(造粒率)이 양호(良好)했고 광물분말 50%까지는 많이 섞을수록 조입율(造粒率)이 증가했다. 조입(造粒)은 물로 가능하며 황산가리(黃酸加里)로만 조입(造粒)할 경우보다 제오라이트와 사문석혼합물(蛇紋石混合物)의 조입(造粒)에는 물이 많이 소요(所要)되나 활석(滑石)의 경우는 감소(減少)했다. 제오라이트는 조입입자(造粒粒子)의 경도(硬度)를 증가시키지만 나머지 광물은 경도(硬度)를 불량(不良)하게 하며 피복조입물(被覆造粒物)은 혼합조입물(混合造粒物)보다 더 쉽게 깨졌다. 낙하파양율(落下破壤率)도 제오라이트가 가장 낮고 혼합비율(混合比率)을 높일수록 더욱 감소(減少)시키며 타광물은 오히려 불량(不良)하게 했다. 피복조립입자(被覆造粒粒子)의 경우는 혼합조입(混合造粒)의 경우와 큰 차이가 없었다. 탈분율도 제오라이트로 혼합(混合), 혹은 피복조입(被覆造粒)할 경우 크게 개선(改善)되었다.

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쿠마 켄고 건축공간에 나타나는 입자화 경향에 관한 연구 (A Study on Tendency of Particles Appearing in Architectural Space Kengo Kuma)

  • 임태희
    • 한국실내디자인학회논문집
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    • 제23권6호
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    • pp.14-21
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    • 2014
  • Kengo Kuma is one of the features of the building is 'natural architecture'. He is saying that the construction of the building in which he is seeking is a natural material of construction is only applied to the issue as to whether the material nature, but that the relationship between humans, the environment, natural point of view in his book. Like repeating units are part of the two hundred ninety-four came mainly small ways to create a relationship, or have architectural features make up the sum of his architecture. I present a comprehensive study is reported in terms of that the 'grain' of such a small part of the unit, according to the architecture of Kengo Kuma mainly granulation characteristics of the construction of one of the practical expression studies Kengo Kuma. Is represented as louvers, check pattern, hole, granulation unit such trend, but have become developed in other directions such simple types are combined. Analysis and particle characteristics in terms of the architectural space of Kengo Kuma, serve as the purpose of the present study reveal that each of the features that have a meaning in the construction of any Kengo Kuma.

四君子湯.四君子湯加黃기 煎湯液이 生肌作用에 미치는 影響 (Effects of Sa Gun Ja Tang(四君子湯) extract and Sa Gun Ja Tang added Radix Astragali(黃기) extract on the Granulation tissues)

  • 안수현;임규상;이기남
    • 한방안이비인후피부과학회지
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    • 제2권1호
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    • pp.17-31
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    • 1989
  • This study was under taken to investigate the healing of Sa Gun Ja Tang extract (SE) and Sa Gun Ja Tang added Radix Astragali extract (SHE) on the artificial wound on rabbit skin. The granulation tissues were observed by microscope at the five day interval for twenty days. In order to understand the healing mechanism chick embryo culture was carried out in the presence of the extracts and the growth ratio and fusion index were counted. The results obtained were as follows: 1. The healing power of SE treated group on wound was more significant than the control group. 2. The healing power on wound was more effective at the SHE than the SE. 3. The growth ratio and fusion index were higher at the SHE treated groups than the SE treated groups. From the above result, SHE was more effective than the SE on wound healing activity by the mechanism of stimulating the cell growth ratio and fusion index.

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Optimization of Fuzzy Set-Fuzzy Systems based on IG by Means of GAs with Successive Tuning Method

  • Park, Keon-Jun;Oh, Sung-Kwun;Kim, Hyun-Ki
    • Journal of Electrical Engineering and Technology
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    • 제3권1호
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    • pp.101-107
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    • 2008
  • We introduce an optimization of fuzzy set-fuzzy systems based on IG (Information Granules). The proposed fuzzy model implements system structure and parameter identification by means of IG and GAs. The concept of information granulation was coped with to enhance the abilities of structural optimization of the fuzzy model. Granulation of information realized with C-Means clustering helps determine the initial parameters of the fuzzy model such as the initial apexes of the membership functions in the premise part and the initial values of polynomial functions in the consequence part of the fuzzy rules. The initial parameters are adjusted effectively with the help of the GAs and the standard least square method. To optimally identify the structure and the parameters of the fuzzy model we exploit GAs with successive tuning method to simultaneously search the structure and the parameters within one individual. We also consider the variant generation-based evolution to adjust the rate of identification of the structure and the parameters in successive tuning method. The proposed model is evaluated with the performance of the conventional fuzzy model.

PHYSICOCHEMICAL CHARACTERIZATION OF UASB GRANULAR SLUDGE WITH DIFFERENT SIZE DISTRIBUTIONS

  • 안영희;송영진;이유진;박성훈
    • 한국지하수토양환경학회:학술대회논문집
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    • 한국지하수토양환경학회 2001년도 총회 및 춘계학술발표회
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    • pp.172-181
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    • 2001
  • Upflow anaerobic sludge blanket (UASB) system employs granular sludge to treat various wastewaters including landfill leachate. CH$_4$ production of the granules determines overall performance of a UASB reactor. Sludge granules are developed by self-granulation of microorganisms and dynamic balance between granule growth and decay results in coexistence of granules with different sizes in the reactor. In this study, granules taken from a laboratory-scale UASB reactor were classified into 4 groups based on their diameters and their Physicochemical characteristics we were investigated. Each group was analyzed for settling ability, specific methanogenic activity (SMA), and elemental content. Settling ability was proportional to granule diameter. suggesting effective detainment of larger granules in the reactor. When acetate or glucose was used as a substrate, all groups showed relatively slight difference in SMA. However SMA with a volatile fatty acid mixture showed significant increase with granule diameter, suggesting better establishment of syntrophic relationship in larger granules. Larger granules showed higher value of SMA upon environmental changes (i.e., PH, temperature, or toxicant concentration). Comparative analysis of elemental contents showed that content (dry weight %) of most tested elements (iron, calcium, phosphorus, zinc, nickel. and manganese) deceased with granule diameter, suggesting importance of these elements for initial granulation. Taken together, this study verified experimentally that Physicochemical Properties of granules are related to granule size distributions. Overall results of physicochemical characterization supports that larger.

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솔-젤/Oil-Drop법을 이용한 이중 다공성 γ-알루미나 그래뉼의 제조 (Synthesis of Bimodally Porous γ-Alumina Granules by Sol-Gel/Oil-Drop Method)

  • 최준서;김진수;이태규
    • 공업화학
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    • 제18권2호
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    • pp.111-115
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    • 2007
  • 메조기공(2~50 nm)과 매크로기공(>50 nm)의 이중 기공구조를 갖는 ${\gamma}$-알루미나 그래뉼을 솔-젤법과 oil-drop법을 이용하여 제조하였다. 메조기공은 알루미나 결정입자간의 공간에서 생성되며, 매크로기공은 합성시 구형의 polystyrene(PS) 입자를 물리적 템플레이트로 혼합한 후 열처리 과정을 거쳐 PS 입자를 연소시킴으로 생성되었다. 제조된 ${\gamma}$-알루미나 그래뉼은 평균 직경이 2 mm였으며, 화학적 물리적 특성은 FE-SEM, XRD, FT-IR, $N_2$ porosimetry, 만능시험기 등을 이용하여 살펴보았다.