• 제목/요약/키워드: effective models

검색결과 3,331건 처리시간 0.03초

동물실험에서 한약제재 경구투여가 비만에 미치는 영향에 대한 국내 연구보고 고찰 - 2010년 이후 발표된 논문을 중심으로 (The Effect of Oral Administration at Herbal Medicines in Animal Models on Obesity: A Review of Animal Study Reports Published in Korea after 2010)

  • 김정민;최수민;양두화;안희덕
    • 한방재활의학과학회지
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    • 제27권3호
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    • pp.13-32
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    • 2017
  • Objectives This study is to review the effect of herbal medicines on obesity in animal models reported in Korean domestic journals after 2010. Methods The Databases (Koreantk, KISS, NDSL) are searched with terms as obesity, and animal study reports on obesity with herbal medicines after 2010 were reviewed. Animal model, intervention, and obesity indicator were extracted. Results 69 articles were reviewed. 57 studies used high fat diet to induce obesity. 56 studies used complex herbal medicines. Most used herbal material for anti-obesity effect is Ephedrae Herba. Each study shows significant changes of obesity indicators. Conclusions These results suggest that herbal medicine is effective treatment to obesity. But we need continuously agonize and research more effective and safe herbal medicine.

대형 설계 시스템의 효율적 반응표면 근사화를 위한 점진적 이차 근사화 기법 (Progressive Quadratic Approximation Method for Effective Constructing the Second-Order Response Surface Models in the Large Scaled System Design)

  • 홍경진;김민수;최동훈
    • 대한기계학회논문집A
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    • 제24권12호
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    • pp.3040-3052
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    • 2000
  • For effective construction of second-order response surface models, an efficient quad ratic approximation method is proposed in the context of trust region model management strategy. In the proposed method, although only the linear and quadratic terms are uniquely determined using 2n+1 design points, the two-factor interaction terms are mathematically updated by normalized quasi-Newton formula. In order to show the numerical performance of the proposed approximation method, a sequential approximate optimizer is developed and solves a typical unconstrained optimization problem having 2, 6, 10, 15, 30 and 50 design variables, a gear reducer system design problem and two dynamic response optimization problems with multiple objectives, five objectives for one and two objectives for the other. Finally, their optimization results are compared with those of the CCD or the 50% over-determined D-optimal design combined with the same trust region sequential approximate optimizer. These comparisons show that the proposed method gives more efficient than others.

Geometric Optimization of a Mathematical Model of Radiofrequency Ablation in Hepatic Carcinoma

  • Wang, Kai-Feng;Pan, Wei;Wang, Fei;Wang, Gao-Feng;Madhava, Pai;Pan, Hong-Ming;Kong, De-Xing;Liu, Xiang-Guan
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권10호
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    • pp.6151-6158
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    • 2013
  • Radio frequency ablation (RFA) is an effective means of achieving local control of liver cancer. It is a particularly suitable mode of therapy for small and favorably located tumors. However, local progression rates are substantially higher for large tumors (>3.0 cm). In the current study, we report on a mathematical model based on geometric optimization to treat large liver tumors. A database of mathematical models relevant to the configuration of liver cancer was also established. The specific placement of electrodes and the frequency of ablation were also optimized. In addition, three types of liver cancer lesion were simulated by computer guidance incorporating mathematical models. This approach can be expected to provide a more effective and rationale mechanism for employing RFA in the therapy of hepatic carcinoma.

다공성 기지를 갖는 복합재의 이미지 기반 전산 모형화 및 기공 탄성 계수 산출 (Image-Based Computational Modeling of Porous Matrix Composites and Calculation of Poroelastic Coefficients)

  • 김성준;신의섭
    • 대한기계학회논문집A
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    • 제38권5호
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    • pp.527-534
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    • 2014
  • 본 논문에서는 이미지 기반 전산 모형을 이용하여 섬유강화 복합재료의 기공 탄성 해석을 수행하였다. 먼저 다공성 기지에 대한 단면 이미지를 분석하여 기공도, 기공 개수, 기공 분포 등을 확인하였다. 이미지의 해상도, 위치, 크기에 따른 전산 모형화 및 유한요소 해석을 수행하였으며, 주요 결과로써 유효 탄성 계수, 기공 탄성 인자, 변형 에너지 밀도를 정량적으로 산출하였다. 기공 탄성 인자는 유효 탄성 계수와 기공 압력에 의한 팽창 변형도를 기준으로 계산하였다. 또한 이미지 기반 전산 모형을 이용한 기공 탄성 해석 결과의 신뢰성 확인을 위해, 기공의 형상 및 배열을 단순화시킨 대표 체적 요소 모형의 해석 결과와 비교하였다.

HEC-HMS와 HEC-RAS모형의 연계에 의한 댐 유역의 홍수영향 분석 (Flood Effects Analysis of Reservoir Basin through the Linkage of HEC-HMS and HEC-RAS Models)

  • 이원희;김선주;김필식
    • 한국농공학회논문집
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    • 제46권2호
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    • pp.15-25
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    • 2004
  • For the effective operation of irrigation reservoirs, a general and systematic policy is suggested to make balance of the conflicting purposes between water conservation and flood control. In this study, the flood effective analysis system was developed through the integration of long-term water budget analysis model, GIS-based HEC-HMS model and HEC-RAS model. The system structure consists of long-term water budget model using modified TANK theory, flood runoff and flood effects analysis model using HEC-GeoHMS, HEC-HMS and HEC-RAS models. The flood effects analysis system simulated the flood runoff from the upstream, downstream flood and long-term runoff of the watershed using the observed data collected from 1998 to 2002 of Seongju dam. The simulated results were reasonably good compared with the observed data. The optimal management method of the reservoir during the whole season is suggested in this study, and the flood analysis system can be a useful tool to evaluate a reservoir operation quantitatively for the mitigation of flood damages of reservoir basin.

3D Quantitative and Qualitative Structure-Activity Relationships of the δ -Opioid Receptor Antagonists

  • Chun, Sun;Lee, Jee-Young;Ro, Seong-Gu;Jeong, Ki-Woong;Kim, Yang-Mee;Yoon, Chang-Ju
    • Bulletin of the Korean Chemical Society
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    • 제29권3호
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    • pp.656-662
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    • 2008
  • Antagonists of the d -opioid receptor are effective in overcoming resistance against analgesic drugs such as morphine. To identify novel antagonists of the d -opioid receptor that display high potency and low resistance, we performed 3D-QSAR analysis using chemical feature-based pharmacophore models. Chemical features for d -opioid receptor antagonists were generated using quantitative (Catalyst/HypoGen) and qualitative (Catalyst/HipHop) approaches. For HypoGen analysis, we collected 16 peptide and 16 non-peptide antagonists as the training set. The best-fit pharmacophore hypotheses of the two antagonist models comprised identical features, including a hydrophobic aromatic (HAR), a hydrophobic (HY), and a positive ionizable (PI) function. The training set of the HipHop model was constructed with three launched opioid drugs. The best hypothesis from HipHop included four features: an HAR, an HY, a hydrogen bond donor (HBD), and a PI function. Based on these results, we confirm that HY, HAR and PI features are essential for effective antagonism of the d -opioid receptor, and determine the appropriate pharmacophore to design such antagonists.

Closed-form optimum tuning formulas for passive Tuned Mass Dampers under benchmark excitations

  • Salvi, Jonathan;Rizzi, Egidio
    • Smart Structures and Systems
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    • 제17권2호
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    • pp.231-256
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    • 2016
  • This study concerns the derivation of optimum tuning formulas for a passive Tuned Mass Damper (TMD) device, for the case of benchmark ideal excitations acting on a single-degree-of-freedom (SDOF) damped primary structure. The free TMD parameters are tuned first through a non-linear gradient-based optimisation algorithm, for the case of harmonic or white noise excitations, acting either as force on the SDOF primary structure or as base acceleration. The achieved optimum TMD parameters are successively interpolated according to appropriate analytical fitting proposals, by non-linear least squares, in order to produce simple and effective TMD tuning formulas. In particular, two fitting models are presented. The main proposal is composed of a simple polynomial relationship, refined within the fitting process, and constitutes the optimum choice. A second model refers to proper modifications of literature formulas for the case of an undamped primary structure. The results in terms of final (interpolated) optimum TMD parameters and of device effectiveness in reducing the structural dynamic response are finally displayed and discussed in detail, showing the wide and ready-to-use validity of the proposed optimisation procedure and achieved tuning formulas. Several post-tuning trials have been carried out as well on SDOF and MDOF shear-type frame buildings, by confirming the effective benefit provided by the proposed optimum TMD.

Analysis of R/C frames considering cracking effect and plastic hinge formation

  • Kara, Ilker Fatih;Ashour, Ashraf F.;Dundar, Cengiz
    • Structural Engineering and Mechanics
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    • 제63권5호
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    • pp.669-681
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    • 2017
  • The design of reinforced concrete buildings must satisfy the serviceability stiffness criteria in terms of maximum lateral deflections and inter story drift in order to prevent both structural and non-structural damages. Consideration of plastic hinge formation is also important to obtain accurate failure mechanism and ultimate strength of reinforced concrete frames. In the present study, an iterative procedure has been developed for the analysis of reinforced concrete frames with cracked elements and consideration of plastic hinge formation. The ACI and probability-based effective stiffness models are used for the effective moment of inertia of cracked members. Shear deformation effect is also considered, and the variation of shear stiffness due to cracking is evaluated by reduced shear stiffness models available in the literature. The analytical procedure has been demonstrated through the application to three reinforced concrete frame examples available in the literature. It has been shown that the iterative analytical procedure can provide accurate and efficient predictions of deflections and ultimate strength of the frames studied under lateral and vertical loads. The proposed procedure is also efficient from the viewpoint of computational time and convergence rate. The developed technique was able to accurately predict the locations and sequential development of plastic hinges in frames. The results also show that shear deformation can contribute significantly to frame deflections.

한국 임상사회복지실천의 효과성 연구 경향에 관한 연구 (Analysis on Effectiveness Research of Clinical Social Work Practice in Korea)

  • 양옥경
    • 한국사회복지학
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    • 제42권
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    • pp.225-253
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    • 2000
  • The objective of this study is to analyze the research articles on clinical social work practice effectiveness to build a scientific and scholaristic image of clinical social work practice. The data for analysis were the articles published in 13 professional journals including Korean J. of Social Welfare in the period of 1979 to 1999. The appearance rate of effectiveness studies was 1.28% with only 18 articles. Experimental studies consisted only 4 out of 18, and there were only 10 Quasi-experimental studies. Statistical errors were observed in most studies, so it is too early to call that the clinical social work practice is either effective or not effective. In order to see the comprehensive trends of the clinical social work practice, other clinical papers were also examined. The appearance rate was also as low as 8.75% (effectiveness studies included). While 18 articles were about the therapy model, other clinical papers were about generic practice models. However, those newly developed generic practice models had not yet been widely used nor tested for effectiveness. Thus, the followings were suggested: active research activities with solid methodology, team work with the field, theory and method development, education and re-education, and collaborative team work with other related fields. It was also pointed that the cross analysis of research papers by the publishing period, authors major and other background variables would be useful.

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제한투기시설에서 배출되는 여수의 거동 (The Behavior of Effluent Discharged from the Confined Dumping Facility)

  • 정대득;이중우
    • 한국항만학회지
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    • 제14권4호
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    • pp.429-439
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    • 2000
  • The primary purpose of dredging work is to maintain navigational readiness and to increase environmental amenity. Therefore the dredging project, which is composed of excavating, removing, transporting and storing or dumping dredged material, must be carefully managed to insure that dredging works are completed in a cost-effective and environmentally safe method. The most important point in dumping operations is evaluating and decreasing the impacts of dumping works at the dumping area. One of the most effective method for this purpose is using the schematic process composed of the sophisticate plan, precise work and predicting/reducing the impacts based on an numerical model being closely linked with field observation. In this study, a numerical model is used to predict the spatial transport and fate of the effluent discharged from the confined dumping facility(CDF) located at a coastal area. To achive this purpose, numerical models were used for reappearing the tidal current of concerned area. These models were then applied to Mokpo harbpr where capital dredging and maintenance dredging are being conducted simultaneously and the CDF is under construction. In series of model case study, we found that the effluent discharged from CDF was governed by the receiving water condition and outfall geometry, so that limit of near-field was 14∼500 meter down stream and 4∼150 meter in transverse direction. dilution ranged from 1.1 to 8.2 on the cases. Long-term diffusion characteristics was governed by the dilution rate during near-field behavior, ambient conditions and CDF operation modes.

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