• Title/Summary/Keyword: N-difference method

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A Study on the Modified N-value by the Comparison Plate Load Test with Calculated Settlement (평판재하시험과 이론적 침하량 예측식의 비교를 통한 N치 보정방법 검토)

  • Ahn, Chang-Yoon;Kim, Won-Cheul;Hwang, Young-Cheol;Nam, Hyun-Woo
    • Journal of the Korean GEO-environmental Society
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    • v.6 no.3
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    • pp.25-34
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    • 2005
  • The governing design point of shallow foundation is not its bearing capacity but its settlemen and N-value by the SPT is one of the key parameters for settlement estimation. However, if the N-value is more than 50/30, such as 50/10 or 50/20, the N-vlaues are not blow count of 30cm depth penetration. In these cases, the estimated settlements have big difference with the measured values because the applied maximum N value for the settlement estimation is 50. Therefore, in this study, the modified method for N-value estimation is suggested. The settlements by four methods, which are based on Elastic Theory with application of modified N-value, are compared with the Origina Plate Load Test data. The same comparision was carried out with another seven Empirical Methods. The result of this study showed that the error range of settlement is decreased from 260.4~2136.5% to 20.3~272.7%. Among four methods which are based on Elastic Theory, the original method by Elastic Theory is the most accurate with the application of modified N-value. Among Empirical Methods, Terzaghi-Peck's(1948, 1967) modified method 1 is the most accurate with the application of modified N-value. The differences between the original method by Elastic Theory and Terzaghi-Peck's(1948, 1967) modified method 1 are neglectable.

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Comparative prospective short-term study on Effect of Electro-Acupuncture on thigh circumference (저주파 전침 자극이 허벅지둘레 감소에 미치는 영향에 관한 단기 연구)

  • Choi, Seung;Lee, Young-Jin;Choi, Hyung-Suk
    • Journal of Korean Medicine for Obesity Research
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    • v.3 no.1
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    • pp.61-67
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    • 2003
  • Objectives : To compare the reduction of thigh circumference between electro acupuncture treatment group and no treatment controlled group. Method : Trial was carried out 24 volunteers for 2 weeks. Volunteers were divided into 2 groups ; electro acupuncture and very low calorie diet group(n=8) or only very low calorie diet group(n=9). The main outcome of measure was the reduction of thigh circumference(cm) per weight loss(kg). Result: The main outcome measure showed no significant difference(p=0.14). There was no significant difference in weight loss(p=0.67) either.

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A ROBUST NUMERICAL TECHNIQUE FOR SOLVING NON-LINEAR VOLTERRA INTEGRO-DIFFERENTIAL EQUATIONS WITH BOUNDARY LAYER

  • Cakir, Firat;Cakir, Musa;Cakir, Hayriye Guckir
    • Communications of the Korean Mathematical Society
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    • v.37 no.3
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    • pp.939-955
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    • 2022
  • In this paper, we study a first-order non-linear singularly perturbed Volterra integro-differential equation (SPVIDE). We discretize the problem by a uniform difference scheme on a Bakhvalov-Shishkin mesh. The scheme is constructed by the method of integral identities with exponential basis functions and integral terms are handled with interpolating quadrature rules with remainder terms. An effective quasi-linearization technique is employed for the algorithm. We establish the error estimates and demonstrate that the scheme on Bakhvalov-Shishkin mesh is O(N-1) uniformly convergent, where N is the mesh parameter. The numerical results on a couple of examples are also provided to confirm the theoretical analysis.

The effect of acupuncture on Choksamni(ST36), Kokchi (LI11) & Arbitrary acupoint on NADPH-diaphorase, neuronal Nitric Oxide Synthase, Neuropeptide Y and Vasoactive Intestinal Peptide in the cerebral cortex of Spontaneously Hypertensive Rats (침자극이 흰쥐 대뇌피질의 NADPH-d와 nNOS, NPY, VIP신경세포에 미치는 영향)

  • Lee, Hyun-soo;Kim, Yong-suk;Kim, Chang-hwan
    • Journal of Acupuncture Research
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    • v.21 no.2
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    • pp.205-222
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    • 2004
  • Objective: To investigate the effects of acupointed Choksamni(ST36), Kokchi(LI11) and Arbitrary acupoint on NADPH-diaphorase, neuronal nitric oxide synthase(nNOS), neuropeptide Y(NPY) and vasoactive intestinal peptide(VIP) in the cerebral cortex of spontaneously hypertensive rats. Methods: The experimental groups were divided into four groups: Normal, Choksamni(ST36), Kokchi(LI11), arbitrary group. Needles were inserted into acupoints at the depth of 0.5 cm with basic insertion method. Such stimulation was applied continuously for 10 minutes, every other day, for 10 sessions of treatments. Thereafter we evaluated changes in NADPH-d-positive neurons histochemically and changes in nNOS, NPY and VIP-positive neurons immunohistochemically. Results : The optical densities of NADPH-d-positive neurons of all the Choksamni & Kokchi groups were significantly different in all areas of cerebral cortex as compared to arbitrary group. In motor1, sensory2, cingulate2, insular, peripheral, visual cortex there was a significant difference between Choksamni & Kokchi group. The optical densities of nNOS-positive neurons of Choksamni group were significantly different in all areas except for auditory, visual and pisiform cortex and Kokchi group in all areas except for auditory and pisiform cortex as compared to arbitrary group. And there was a significant difference in cingulate1, cingulate2, ectohinal, visual cortex between Choksamni & Kokchi group. The optical densities of NPY neurons of Choksamni group were significantly different in cingulate2, insular, pisiform cortex and Kokchi group in motor1, motor2, sensory1, cingulate2, ectorhinal cortex as compared to arbitrary group. And there was no significant difference between Choksamni & Kokchi group. The optical densities of VIP neurons of Choksamni group were significantly different in all areas except for motor1, auditory cortex and Kokchi group in sensory1, insular, ectorhinal, perirhinal, visual, pisiform cortex as compared to arbitrary group. And there was a significant difference in cingulate1, cingulate2, retrosplenial, auditory corterx between Choksamni & Kokchi group. Conclusion : Our results demonstrated that acupuncture on Choksamni(ST36) & Kokchi(LI11) changes the control activities of the NO system in the cerebral cortex of SHR and according to areas there were significant difference between two groups. In all cerebral cortex areas there were distributed NPY & VIP and there were no significant difference among Choksamni(ST36), Kokchi(LI11) and arbitrary group.

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ROTATION IMPLEMENTATION OF A CIRCULAR CYLINDER IN INCOMPRESSIBLE FLOW VIA STAGGERED GRID APPROACH

  • Xiao Mingqing;Lin Yuan;Myatt James H.;Camphouse R. Chris;Banda Siva S.
    • Journal of applied mathematics & informatics
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    • v.22 no.1_2
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    • pp.67-82
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    • 2006
  • In this paper, we present a finite difference method for the implementation of the rotation of a circular cylinder in the incompressible flow field by solving the two-dimensional unsteady Navier-Stokes equations. The approach is to use staggered grid method so that the accuracy and order of convergence of the associated algorithms can be maintained. The proposed method is easy to be implemented and is effective. A set of simulations for the flow dynamics is provided to show the computational results.

A MODEL STUDY ON MULTISTEP RECOVERY OF ACTINIDES BASED ON THE DIFFERENCE IN DIFFUSION COEFFICIENTS WITHIN LIQUID METAL

  • CHUN, YOUNG-MIN;SHIN, HEON-CHEOL
    • Nuclear Engineering and Technology
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    • v.47 no.5
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    • pp.588-595
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    • 2015
  • This study presents an effective method for additional recovery of residual actinides in liquid electrodes after the electrowinning process of pyroprocessing. The major distinctive feature of this method is a reactor with multiple reaction cells separated by partition walls in order to improve the recovery yield, thereby using the interelement difference in diffusion coefficients within the liquid electrode and controlling the selectivity and purity of element recovery. Through an example of numerical simulation of the diffusion scenarios of individual elements, we verified that the proposed method could effectively separate the actinides (U and Pu) and rare-earth elements contained in liquid cadmium. We performed a five-step consecutive recovery process using a simplified conceptual reaction cell and recovered 58% of the initial amount of actinides (U + Pu) in high purity (${\geq}99%$).

The Effects of Joint Mobilization and Muscle Strength Exercise on Neck Function and Range of Motion in Forward Head Posture (관절가동술과 근력강화운동이 앞쪽머리자세 환자의 목기능과 근긴장도에 미치는 영향 )

  • Jin-young Kim;Jeon-youn Choi;Hyun-seung Song
    • The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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    • v.29 no.3
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    • pp.23-30
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    • 2023
  • Background: The purpose of this study was to investigate the effects of joint mobilization and muscle strengthening exercises on neck function, range of motion, and muscle tone in patients with forward head posture. Methods: A total 32 subjects were divided into muscle strengthening exercise (n=16) and joint mobilization (n=16) who met the diagnostic criteria for the forward head posture, and the study method used the neck disability index (NDI) and BPM Pro to compare the range of motion. Results: As a result of the study, there was no significant difference between each group, and when looking at the differences before and after each group, there was a significant difference in neck pain in both groups. There was a significant difference in muscle tension in the joint mobilization group, but there was no significant difference in the muscle strengthening exercise group. In the range of joint mobilization, there was a significant difference in the range of left joint mobilization of the joint mobilization group, there was no significant difference in the range of right joint mobilization, and there was no significant difference in the range of joint mobilization of the muscle strengthening exercise group. Conclusion: The above results revealed that joint mobilization and muscle strengthening exercises were effective on neck function, range of motion, and muscle tone in forward head posture patients.

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AM1 Studies on the Gas-Phase Pyrolysis of Iminoethers, 2-Alkoxypyridines, 2-N-Alkylated Pyridones and N-Alkylated Acetamides

  • Bon-Su Lee;Chang Kon Kim;Ikchoon Lee
    • Bulletin of the Korean Chemical Society
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    • v.12 no.5
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    • pp.560-564
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    • 1991
  • The gas-phase pyrolysis reactions of iminoethers (Ⅱ), 2-alkoxypyridines (Ⅲ), 2-N-alkylated pyridones (Ⅳ) and N-alkylated acetamides (Ⅴ) have been studied MO theoretically with the AM1 method. The decomposition of these compounds proceeds by a concerted retro-ene process through a six-membered cyclic transition state. The reactivity decreases in the order (Ⅱ) > (Ⅲ) > (Ⅳ) > (Ⅴ), with a greater reactivity for the imine series, (Ⅱ) and (Ⅲ), compared to the amide series, (Ⅳ) and (Ⅴ), and a difference in basicity between the N and O atoms. Within a given series, however, the reactivity is dictated mainly by the aromaticity in the transition state. The reactivity order with respect to side alkyl chain of a species was found to increase as the steric crowding effect increases. The AM1 reactivity in this work agree well with the experimental results.

The controversial points for the assessment of soil contamination related to the change of pH of extraction solution in using partial extraction in standard method in Korea (국내 토양오염 공정시험방법의 용출법 사용시 용출액의 pH의 변화가 토양 오염 평가에 미치는 문제점)

  • 오창환;유연희;이평구;이영엽
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.11a
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    • pp.294-297
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    • 2000
  • Heavy metals are extracted from Chonju stream sediment, roadside soils and sediments along Honam expressway, soils and tailings from mining area using partial ectraction in Standard Method, partial ectraction method with maintaining 0.1N of extraction solution and acid digestion. In samples having buffer capacity against acid, 0.1N of extraction solution can not be maintained and pH of extraction solution increases up to 8.0 when partial extraction in Standard Method is used. The averages and ranges of (heavy metals extracted using partial extraction in standard method, HPE)/(heavy metals extracted using partial extraction method with maintaining 0.1N of extraction solution, HPEM) values are 0.506 and 0.145~1.126 in Cd, 0.534~ and 0.078~0.928 in Zn, 0.461 and 0.041~1.715 in Mn, 0.359 and 0.011~0.874 in Cu, 0.195 and 0.018~1.785 in Cr, 0.710 and 0.003~3.075 in Pb, and 0.088 and 1.73$\times$10$^{-5}$ ~0.303 in Fe. These data indicate that the difference between HPE and HPEM is big in the order of Fe, Cr, Cu, Mn, Cd, Zn and Pb. It is quite possible that the partial extraction method in Standard Method of soil in Korea is not adequate for an assessment of contamination in area where buffer capacity of soil will be decreased or lost after a long term exposure of soils to environmental damage.

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