• Title/Summary/Keyword: numerical methods

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Five Cases of Nonstructural Scoliosis with Lumbar Herniated Intervertebral Disc Treated by Complex Korean Medicine Treatment with Chuna Manual Therapy: Case Report (추나요법을 적용한 한방복합치료로 호전된 요추 추간판 탈출증으로 인한 비구조적 척추측만증 5례: 증례보고)

  • Namgoong, Jin;Hwang, Bo-Kyung;Shin, Won-Bin;Choi, Hyo-Jung;Baek, Hye-Kyung;Lee, Yun-Ha;Choi, Dong-Joo
    • The Journal of Churna Manual Medicine for Spine and Nerves
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    • v.15 no.1
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    • pp.121-134
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    • 2020
  • Objectives : This case report describes the management of five patients suffering from nonstructural scoliosis with lumbar herniated intervertebral disc all treated with complex Korean medicine treatment. Methods : Five patients were hospitalized and treated with herbal medicine, acupuncture, pharmacopuncture, cupping, and Chuna manual therapy. Patients were assessed for Numerical Rating Scale (NRS), Oswestry Disability Index (ODI), EuroQol-FiveDimensions (EQ-5D), and Cobb's angle. Results : In all patients, NRS, ODI, and Cobb's angle decreased, while the EQ-5D score increased. Conclusions : As seen in these five cases, complex Korean medicine treatment with Chuna manual therapy has effects on the management of nonstructural scoliosis.

The Changes of Mucin and Endocrine cells of Mucosa of Acetic Acid-Induced Gastric Ulcer after Administration of Whadamcheongwha-tang Extract in Rat (화담청화탕이 acetic acid로 유발된 흰쥐 위궤양 점막의 내분비세포와 점액의 조직화학적 변화)

  • Kang Gyung Rae;Yuk Sang Won;Ko Hyoung Gon;Lee Kwang Gyu;Lee Chang Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.16 no.6
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    • pp.1170-1176
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    • 2002
  • We examined the effects of Whadamcheongwha-tang(WDCWT) extract on the acetic-acid induced antigastric ulcer in rats. These experiments investigated the numerical changes of gastrin and histamine secreting cells of the gastric mucosa by immunohistochemical method, and the changes of mucin of gastric mucosa by PAS-AB stain methods after the oral administration of WDCWT extract(1.0ml/day) and omeprazole(0.2mg/day) for 1, 3 and 6 weeks. The result are as follows; 1. When WDCWT extract was administrated for 1, 3, 6 weeks, in result, gastrin secreting cells in gastric mucosa were increased compared to the control group. 2. When WDCWT extract was administrated for 1, 3, 6 weeks, in result, the density of immunoreactive gastrin cells was increased compare to the control group. 3. When WDCWT extract was administrated for 1, 3, 6 weeks, in results, the changs of mucosal thickness stained by PAS/PAS-AB was increased compared to the control group. 4. When WDCWT extract was administrated for 1, 3, 6 weeks, in results, the density of PAS stain was decreased compare to control group, but density of AB stain was increased compare to control group. The results suggest that WDCWT extract inhibits a gastric acid secretion in rat gastric mucosa, and is useful in the treatment of the hyperacidity and gastric ulcer.

The study of comparison about the stress's control experiments (항(抗)Stress 실험에 관한 비교 연구)

  • Kim Keun-Woo;Ku Byung-Su
    • Journal of Oriental Neuropsychiatry
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    • v.8 no.1
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    • pp.111-125
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    • 1997
  • This study was done in order to investigate Oriental Medicine's meaning on stress, the stress is due to animal experiments.Methods:This research was done by animal experiments's results based on 41 animal experiment treatises carried out by 24 prescriptions about stress control. Each experiments were compared with same conditions, minimizing the experiments differences. The results were analyzed by p-value and Increas e·Decrease percentage of experiments result's numerical value. Results:1. Inquire into frequency in use of each stress stimulus and measuring items, the restriction stimulus stress and measuring the content of catecholamines are numerous.2. Significance of stress stimuluses based on experments's results is good by restriction stimulus.3. Oriental Medicine's meaning for stress is pathological phenomenon of Seven Emotion(七情). Stagnant the Energy(氣鬱), the Fire(火), Dam(痰), Lack of the general Blood thing(血虛), and reaction of an individual body.4. Inguire into the effects of frequency in use of experiments's Herb drugs, Herb Drugs of Tonifing the general Blood thing depend on stabilized Mind(補血安神), Circulated the Energy and Digest(理氣消導), Tonifing the general Blood thing(補血), Clearing the Mind(淸心), Removing the Dam(祛痰) are numerous.5. From a Sasang Medical point of view, experimental use of Herb Drugs are Soeum-in(少陰人) Herb Drugs are numerous.According to above results, it is considered that Herb Drugs of Tonifing the general Blood thing depend on stabilized Mind(補血安神), Circulated the Energy and Digest(理氣消導), Tonifing the general Blood thing(補血), Clearing the Mind(淸心), Removing the Dam(祛淡), and Soeum-in(少陰人) Herb Drugs are used to prevent stress and related diseases.

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Computational Thermo-Fluid Analysis for the Effects of Helium Injection Methods on Glass Fiber Cooling Process in an Optical Fiber Manufacturing System (광섬유 냉각장치의 헬륨 주입기 설계를 위한 전산열유동해석)

  • Park, Shin;Kim, Kyoungjin;Kim, Dongjoo;Park, Junyoung;Kwak, Ho Sang
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.13 no.2
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    • pp.124-130
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    • 2014
  • In a mass manufacturing system of optical fibers, the sufficient cooling of glass fibers freshly drawn from a draw furnace is essential, asinadequately cooled glass fibers can lead to poor resin coating on the fiber surface and possibly fiber breakage during the process. In order to improve fiber cooling at a high drawing speed, it is common to use a helium injection into a glass fiber cooling unit in spite of the high cost of the helium supply. The present numerical analysis carried out three-dimensional thermo-fluid computations of the cooling gas flow and heat transfer on moving glass fiber to determine the cooling performance of glass fiber cooling depending on the method of helium injection. The results showed that afront injection of helium is most effective compared to a uniform or rear injection for reducing air entrainment into the unit and thus cooling the glass fibers at a high fiber drawing speed. However, above a certain amount of injected helium, there was no more increase of the cooling effect regardless of the helium injection method.

Application of MS Excel in Teaching Statics (엑셀 프로그램을 활용한 정역학 교육 사례)

  • Kim, Youngheub
    • Transactions of the KSME C: Technology and Education
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    • v.2 no.1
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    • pp.21-28
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    • 2014
  • As one of the most famous spreadsheet programs that is widely applied to a variety of fields in business, MS Excel has also been used for educational purposes due to its feature of wide accessibility, enabling students to use the program through almost any kind of PC that now exists. The program is mainly used for numerical analysis and formulae applications in the fields of science and engineering. This paper shall provide the key to understanding the application of MS Excel to teaching Statics through the illustration of its essential functions for education. Also, the development process of the analysis program using macros and VBA(Visual Basic for Applications) is described for the deeper comprehension of advanced applications. Students were not only able to solve the Statics problems using basic features of MS Excel, but also discovered new systematic methods of approaching complex problems and developed application programs using macros and VBA.

Fuzzy reliability analysis of laminated composites

  • Chen, Jianqiao;Wei, Junhong;Xu, Yurong
    • Structural Engineering and Mechanics
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    • v.22 no.6
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    • pp.665-683
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    • 2006
  • The strength behaviors of Fiber Reinforced Plastics (FRP) Composites can be greatly influenced by the properties of constitutive materials, the laminate structures, and load conditions etc, accompanied by many uncertainty factors. So the reliability study on FRP is an important subject of research. Many achievements have been made in reliability studies based on the probability theory, but little has been done on the roles played by fuzzy variables. In this paper, a fuzzy reliability model for FRP laminates is established first, in which the loads are considered as random variables and the strengths as fuzzy variables. Then a numerical model is developed to assess the fuzzy reliability. The Monte Carlo simulation method is utilized to compute the reliability of laminas under the maximum stress criterion. In the second part of this paper, a generalized fuzzy reliability model (GFRM) is proposed. By virtue of the fact that there may exist a series of states between the failure state and the function state, a fuzzy assumption for the structure state together with the probabilistic assumption for strength parameters is adopted to construct the GFRM of composite materials. By defining a generalized limit state function, the problem is converted to the conventional reliability formula that enables the first-order reliability method (FORM) applicable in calculating the reliability index. Several examples are worked out to show the validity of the models and the efficiency of the methods proposed in this paper. The parameter sensitivity analysis shows that some of the mean values of the strength parameters have great influence on the laminated composites' reliability. The differences resulting from the application of different failure criteria and different fuzzy assumptions are also discussed. It is concluded that the GFRM is feasible to use, and can provide an effective and synthetic method to evaluate the reliability of a system with different types of uncertainty factors.

Damage assessment of shear connectors with vibration measurements and power spectral density transmissibility

  • Li, Jun;Hao, Hong;Xia, Yong;Zhu, Hong-Ping
    • Structural Engineering and Mechanics
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    • v.54 no.2
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    • pp.257-289
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    • 2015
  • Shear connectors are generally used to link the slab and girders together in slab-on-girder bridge structures. Damage of shear connectors in such structures will result in shear slippage between the slab and girders, which significantly reduces the load-carrying capacity of the bridge. Because shear connectors are buried inside the structure, routine visual inspection is not able to detect conditions of shear connectors. A few methods have been proposed in the literature to detect the condition of shear connectors based on vibration measurements. This paper proposes a different dynamic condition assessment approach to identify the damage of shear connectors in slab-on-girder bridge structures based on power spectral density transmissibility (PSDT). PSDT formulates the relationship between the auto-spectral densities of two responses in the frequency domain. It can be used to identify shear connector conditions with or without reference data of the undamaged structure (or the baseline). Measured impact force and acceleration responses from hammer tests are analyzed to obtain the frequency response functions at sensor locations by experimental modal analysis. PSDT from the slab response to the girder response is derived with the obtained frequency response functions. PSDT vectors in the undamaged and damaged states can be compared to identify the damage of shear connectors. When the baseline is not available, as in most practical cases, PSDT vectors from the measured response at a reference sensor to those of the slab and girder in the damaged state can be used to detect the damage of shear connectors. Numerical and experimental studies on a concrete slab supported by two steel girders are conducted to investigate the accuracy and efficiency of the proposed approach. Identification results demonstrate that damages of shear connectors are identified accurately and efficiently with and without the baseline. The proposed method is also used to evaluate the conditions of shear connectors in a real composite bridge with in-field testing data.

A new high-order response surface method for structural reliability analysis

  • Li, Hong-Shuang;Lu, Zhen-Zhou;Qiao, Hong-Wei
    • Structural Engineering and Mechanics
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    • v.34 no.6
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    • pp.779-799
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    • 2010
  • In order to consider high-order effects on the actual limit state function, a new response surface method is proposed for structural reliability analysis by the use of high-order approximation concept in this study. Hermite polynomials are used to determine the highest orders of input random variables, and the sampling points for the determination of highest orders are located on Gaussian points of Gauss-Hermite integration. The cross terms between two random variables, only in case that their corresponding percent contributions to the total variation of limit state function are significant, will be added to the response surface function to improve the approximation accuracy. As a result, significant reduction in computational cost is achieved with this strategy. Due to the addition of cross terms, the additional sampling points, laid on two-dimensional Gaussian points off axis on the plane of two significant variables, are required to determine the coefficients of the approximated limit state function. All available sampling points are employed to construct the final response surface function. Then, Monte Carlo Simulation is carried out on the final approximation response surface function to estimate the failure probability. Due to the use of high order polynomial, the proposed method is more accurate than the traditional second-order or linear response surface method. It also provides much more efficient solutions than the available high-order response surface method with less loss in accuracy. The efficiency and the accuracy of the proposed method compared with those of various response surface methods available are illustrated by five numerical examples.

Improvement of Concrete Lining Construction Method in Large Section Tunnel (대단면 터널 라이닝 콘크리트 타설 기법 개선에 관한 연구)

  • Kim, Sang-Whang;Ra, Kyong-woong;Koh, Sung-Yil
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.8 no.1
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    • pp.77-86
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    • 2006
  • Although the adverse critisism have been continued that the concrete lining need or not, most tunnel engineer agree that the concrete lining needs to increase the tunnel safety To establish the concrete lining's quality improvement method, we grasp the basic problems in lining construction process and propose the lining construction methods to increase the concrete quality This paper present a reason of initial crack occurrence in the large section tunnel (4 lane wide span tunnel), lining and an improved method for crack minimization in construction process. It is also verified verify that the proposed method can give qualified concrete lining by carrying out the concrete injection model test and the numerical analysis of concrete flow.

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A study on the effective fire and smoke control in transverse oversized exhaust ventilation (횡류식 선택대배기환기에서의 배연특성에 관한 연구)

  • Han, Sang-Pil;Jeon, Yong-Han
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.13 no.6
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    • pp.451-462
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    • 2011
  • The smoke control system plays the most important role in securing evacuation environment when a fire occurs in road tunnels. Smoke control methods in road tunnels are classified into two categories which are longitudinal ventilation system and transverse ventilation system. In this study it is intended to review the characteristics of smoke behavior by performing numerical analysis for calculating the optimal smoke exhaust air volume with scaled-model and simulation when a fire occurs in tunnels in which transverse ventilation is applied, and for obtaining the basic data required for the design of smoke exhaust systems by deriving optimal smoke exhaust operational conditions for various conditions. As a result of this study, when the critical velocity in the tunnel is 1.75 m/s and 2.5 m/s, the optimal smoke exhaust air volume has to be more than $173m^3/s$, $236m^3/s$ for the distance of the smoke moving which can limit the distance to 250 m. In addition, in case of uniform exhaust the generated smoke is effectively taken away if the two exhaust holes near the fire region are opened at the same time.