• Title/Summary/Keyword: numerical index

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Fire Needling Therapy in Patients with a Vertebral Compression Fracture: A Report of Three Cases (가열식 화침을 이용한 척추 압박골절 환자 증례보고)

  • Kim, Tae-Ryeong;Kim, Young-Jun;Woo, Chang-Hoon
    • Journal of Korean Medicine Rehabilitation
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    • v.27 no.4
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    • pp.147-154
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    • 2017
  • The purpose of this study is to report the effectiveness of Fire needling therapy in patients with a vertebral compression fracture. Three patients with a acute vertebral compression fracture were treated using Fire needling therapy. To evaluate the effectiveness of Fire needling therapy, we checked Numerical rating scale on a daily and Oswestry disability index on admission and discharge. Numerical rating scale decreased as the number of Fire needling therapy increased. Oswestry disability index on discharge improved compared to admission. The limitation of this study is the insufficient number of cases and outcome measurements. Further studies are needed to prove effect and safety.

Damage Estimation of Simple Beams using Damage Index : I. Theory and Numerical Analysis (손상지수를 이용한 단순보의 손상추정 I. 이론 및 수치 해석)

  • Kim, Hak Su;Chang, Dong Il
    • Journal of Korean Society of Steel Construction
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    • v.8 no.4 s.29
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    • pp.43-50
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    • 1996
  • Damage estimation of bridge structures has recently received considerable attention in the light of maintenance and retrofitting of existing structures under service loads and after natural disasters. A method for the damage assessment of bridge structures using a damage index technique is presented. The damage index is formulated for the changes of modal properties due to the change of the stiffness. In order to verify the method which is presented, numerical analysis is conducted on simple beam models. Each FE model is subjected to different damage scenarios, i.e., locations and degrees of damage. Results of numerical analysis indicate that the proposed method is capable of detecting inflicted damages using the eigenvalue of only first mode.

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Numerical and Experimental Investigation on NOx Emission Characteristics of $CH_4$ Jet Flame ($CH_{4}$ 제트 화염의 NOx 배출 특성에 관한 수치 및 실험적 연구)

  • Park, Jung-Bae;Kim, Jong-Hyun;Lee, Chang-Eon
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.67-76
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    • 2000
  • Experimental and numerical investigation on NOx emission characteristics with equivalence ratios, fuel flow rates and nozzle diameters were studied in CH4 Jet flames. Emission indices of NOx were measured by chemiluminescent method with carbon converter. Numerical analyses were carried out with GRl-2.11 mechanism that includes C2-chemistry and all of NO reaction mechanisims. The roles of thermal NO and prompt NO mechanism on each flame's NOx emission index were investigated. The results of this study show that the numerical results represent well the trends of ElNOx experimentally observed. The numerical analyses clarified the trends of EINOx with equivalence ratios, fuel flow rates and nozzle diameters.

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An Analysis Code and a Planning Tool Based on a Key Element Index for Controlled Explosive Demolition

  • Isobe, Daigoro
    • International Journal of High-Rise Buildings
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    • v.3 no.4
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    • pp.243-254
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    • 2014
  • In this study, a demolition analysis code using the adaptively shifted integration (ASI)-Gauss technique, which describes structural member fracture by shifting the numerical integration point to an appropriate position and simultaneously releasing the sectional forces in the element, is developed. The code was verified and validated by comparing the predicted results with those of several experiments. A demolition planning tool utilizing the concept of a key element index, which explicitly indicates the contribution of each structural column to the vertical load capacity of the structure, is also develped. Two methods of selecting specific columns to efficiently demolish the whole structure are demonstrated: selecting the columns from the largest index value and from the smallest index value. The demolition results are confirmed numerically by conducting collapse analyses using the ASI-Gauss technique. The numerical results suggest that to achieve a successful demolition, a group of columns with the largest key element index values should be selected when explosives are ignited in a simultaneous blast, whereas those with the smallest should be selected when explosives are ignited in a sequence, with a final blast set on a column with large index value.

Health risk assessment by CRPS and the numerical model for toluene in residential buildings

  • Choi, Haneul;Kim, Hyungkeun;Kim, Taeyeon
    • KIEAE Journal
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    • v.17 no.5
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    • pp.33-41
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    • 2017
  • Purpose: Indoor air quality in residential buildings needs to be evaluated over the long term. In previous research, there has been an attempt to perform the health risk assessment of pollutants by using numerical models as a method of long-term evaluation. However, the numerical model of this precedent study has limitations that do not reflect the actual concentration distribution. Therefore, this study introduces the CRPS index, constructs a numerical model that can reflect the concentration distribution, and then presents a more accurate health risk assessment method using it. At this time, the pollutants are toluene, which is a typical material released from building materials. Method: CRPS index was applied to existing numerical model to reflect concentration distribution. This was used to calculate concentrations at adult breathing area and to use them for exposure assessment in a health risk assessment. After that, we entered adult data and conducted a health risk assessment of toluene. Results: The non-carcinogenic risk of toluene was calculated to be 0.0060. This is 5% smaller than the existing numerical model, meaning that it is more accurate to predict the pollutant risks. This value is also lower than the US EPA reference value of 1. Therefore, under the conditions of this study, long-term exposure of adults to toluene has no impact on health.

Performance of rotational mode based indices in identification of added mass in beams

  • Rajendrana, Prakash;Srinivasan, Sivakumar M.
    • Structural Engineering and Mechanics
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    • v.54 no.4
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    • pp.711-723
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    • 2015
  • This study investigates the identification of added mass and its location in the glass fiber reinforced polymer (GFRP) beam structures. The main emphasis of this paper is to ascertain the importance of inclusion of rotational degrees of freedom (dofs) in the introduction of added mass or damage identification. Two identification indices that include the rotational dofs have been introduced in this paper: the modal force index (MFI) and the modal rotational curvature index (MRCI). The MFI amplifies damage signature using undamaged numerical stiffness matrix which is related to changes in the altered mode shapes from the original mode shapes. The MRCI is obtained by using a higher derivative of rotational mode shapes. Experimental and numerical results are compared with the existing methods leading to a conclusion that the contributions of the rotational modes play a key role in the identification of added mass. The authors believe that the similar results are likely in the case of damage identification also.

Study on the Interrelationship among the Environmental Factors in Environmental Impact Assessment (환경영향평가에서의 평가항목간 상호연계성에 관한 연구)

  • Kang, Myung-Hwi;Lee, Mu-Choon
    • Journal of Environmental Impact Assessment
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    • v.8 no.3
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    • pp.49-59
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    • 1999
  • In this study, we individualize the clauses to sort out the troubled ones, draw up a interrelation model in order to visually organize the relations, and finally, suggest the desirable application idea. The interrelation model suggested in this study has been made based on the matrix method. On this matrix, we arranged the environmental factors on horizontal and vertical axis, and when we describe the relation of each factors, we set the horizontal axis as the base and divided the content into three grades : Fine, Medium, and Poor. In addition to that, we expressed those three grades into numerical value like 3 points for Level Fine, 2 points for Level Medium, and 1 point for Level Poor and then, we converted this numerical values into index numbers. We could classify the index numbers such as AS, PS, Q-index, P-index. AS is an index numerically shows the degree of giving environmental effect, PS is an index numerically shows the degree of receiving environmental effect, Q-index is an index shows the aggravate degree, and P-index shows the relation degree. The Q/P-index with large numbers has considerable effect on the environmental system, while the small numbered Q/P-index barely effect on the environmental system. Moreover, we classified the environmental factors into 5 levels(I~V) according to the relations between the Q-index and P-index. Level I is less affected by the environment and has more giving effect, while Level V is more sensitively affected by the environment and has more receiving effect, which we considered important. Therefore, we could come up with the result that if we consider the each level of factors when we evaluate the EIA, the result would be far more accurate and reliable since it contains mutual relation aspect of EIA. The suggested interrelation model in this thesis is presentable as one of those scoping system. We highly believe the need of scoping system in EIA and suggest the interrelation model as the alternative idea for scoping system.

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NUMERICAL METHODS SOLVING THE SEMI-EXPLICIT DIFFERENTIAL-ALGEBRAIC EQUATIONS BY IMPLICIT MULTISTEP FIXED STEP SIZE METHODS

  • Kulikov, G.Yu.
    • Journal of applied mathematics & informatics
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    • v.4 no.2
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    • pp.341-378
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    • 1997
  • We consider three classes of numerical methods for solv-ing the semi-explicit differential-algebraic equations of index 1 and higher. These methods use implicit multistep fixed stepsize methods and several iterative processes including simple iteration, full a2nd modified Newton iteration. For these methods we prove convergence theorems and derive error estimates. We consider different ways of choosing initial approximations for these iterative methods and in-vestigate their efficiency in theory and practice.