• Title/Summary/Keyword: Stiffness curve

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A Clinical Study of Headache in 58 Cases (두통(頭痛)의 임상양상(臨床樣狀) 및 생체전기자율반응에 대(對)한 임상적(臨床的) 고찰(考察))

  • Lee Sang-Ryong;Kim Myung-Jin
    • Journal of Oriental Neuropsychiatry
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    • v.12 no.2
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    • pp.103-122
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    • 2001
  • The clinical study was carried out the 58 patients with Headache who were treated in Department of Neuropsychiatry, College of Oriental Medicine, Dae Jeon University from 14 October 1999 to 15 October 2001. The results were summarized as follows. 1. The ratio of male and female was 15:43, 40s(36.2%) was frequent, the ratio of Tension headache and Migraine was 43:12, hypernoia and overwork oneself were the most inducing factor. 2. In distribution of the period of the clinical history, Tension headache was comparatively short term within 1 month(62.8%) and Migraine was comparatively long term over 1 year(91.7%), Tension headache was frequent at whole portion(41.3%) and occipital portion(26.1%), Migraine was frequent at temporal portion(76.9%). 3. In pain type, Tension headache has many vandlike discomport type, Migraine has many pulsatile type, neck-stiffness-pain and dizziness were mainly coexited. 4. Toung aspect has many SULDAMHONGTAEBAEKHOO(舌淡紅苔白厚), GINMAEK(緊脈) and HEUNMAEK(弦脈) were frequent in Pulse type, the GAEDAMSUNKIJEETONG(祛淡順氣止痛) prescription drugs were frequent such as GEYNTONGA(肩痛A), GEYNTONGDODAMTANG(?通導淡湯), Tension headache patients were well treated(90.7%). 5. In Tension headache and Migraine, the Curve has many SL except Tension headache‘s 2th SANGHAN(상한), in Regulation RR was frequent at 1th, 2th, 3th, 4th, 7th SANGHAN and RL was frequent at 5th, 6th SANGHAN, the result of Graph, Activity and Reactivity have many low response at the whole. 6. The Curve was within normal limit at whole portion and frequent SL at temporal portion, the whole and temporal portion s Regulation also have many RR at 1th, 2th, 3th, 4th, 7th SANGHAN and RL at 5th, 6th SANGHAN, Activity and Reactivity have many low response at the whole. 7. The occipital and frontal portion‘s Curve have many SL at 1th SANGHAN, the occipital portion’s Regulation has many RR at 1th, 2th, 4th, 7th SANGHAN and RL at 5th, 6th SANGHAN, Activity has many low response at the whole, Reactivity has many low response at 1th, 4th, 5th, 6th SANGHAN and high response 2th, 3th SANGHAN, the frontal portion s Regulation has many RL at 1th, 3th, 5th, 6th, 7th SANGHAN and RR at 4th SANGHAN, Activity and Reactivity also have many low response at the whole except 6th, 7th SANGHAN respectively.

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Soil-Water Characteristic Curve of Sandy Soils Containing Biopolymer Solution (바이오폴리머를 포함한 모래지반의 흙-습윤 특성곡선 연구)

  • Jung, Jongwon
    • Journal of the Korean GEO-environmental Society
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    • v.19 no.10
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    • pp.21-26
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    • 2018
  • Soil-water characteristic curve, which is called soil retention curve, is required to explore water flows in unsaturated soils, relative permeability of water in multi-phase fluids flow, and change to stiffness and volume of soils. Thus, the understanding of soil-water characteristic curves of soils help us explore the behavior of soils inclduing fluids. Biopolymers are environmental-friendly materials, which can be completely degraded by microbes and have been believed not to affect the nature. Thus, various biopolymers such as deacetylated power, polyethylene oxide, xanthan gum, alginic acid sodium salt, and polyacrylic acid have been studies for the application to soil remediation, soil improvement, and enhanced oil recovery. PAA (polyacrylic acid) is one of biopolymers, which have shown a great effect in enhanced oil recovery as well as soil remediation because of the improvement of water-flood performance by mobility control. The study on soil-water characteristic curves of sandy soils containing PAA (polyacrylic acid) has been conducted through experimentations and theoretical models. The results show that both capillary entry pressure and residual water saturation dramatically increase according to the increased concentration of PAA (polyacrylic acid). Also, soil-water characteristic curves by theoretical models are quite well consistent with the results by experimental studies. Thus, soil-water characteristic curves of sandy soils containing biopolymers such as PAA (polyacrylic acid) can be estimated using fitting parameters for the theoretical model.

Validity of Linear Combination Approach based on Net Damping Analysis of Cable-Damper System (케이블-댐퍼 시스템의 전체감쇠비 해석을 통한 선형조합 접근법의 유효성)

  • Kim, Hyeon Kyeom;Hwang, Jae Woong;Lee, Myeong Jae
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.5A
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    • pp.467-475
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    • 2009
  • Existing studies have suggested Universal Curve only for supplemental damping by damper. Therefore net damping has been determined by means of arithmetic summation between intrinsic, aero-damping of cable and supplemental damping of damper. However linear combination approach by means of the arithmetic summation is not enough theoretical background. So validity of this approach should be verified in order to design adequate cable-damper system by engineers. This study establishes governing differential equation which can consider intrinsic, aero-damping and supplemental damping as well. And also analysis method is solved by combination of muller method and successive iteration method. Consequently, this study succeeds in verification for validity of linear combination approach. As a result of this study, linear combination approach is limitedly effective in case of low stiffness and optimum damping coefficient of damper, short distance from support to damper, lower vibration mode, low aero-damping, and normal windy environment. Whereas this study will be effective in case of opposite conditions, and existing studies or linear combination approach occur to further error. Meaning of this study presents exact solution for net damping of cable-damper system, and verifies linear combination approach by means of the analysis method. In the future, if monitoring of optimum damping coefficient of a damper against aero-damping is feasible on time, algorithm of this study will be available for control of cable and semi-active damper system such as magneto-rheological damper.

An experimental study on diameter increase of orthodontic wire by electroplating (전기도금을 이용한 스테인레스 스틸 선재의 직경 증가에 관한 실험적 연구)

  • Cho, Jin-Hyoung;Sung, Young-Eun;Lee, Ki-Heon;Hwang, Hyeon-Shik
    • The korean journal of orthodontics
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    • v.33 no.2 s.97
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    • pp.121-130
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    • 2003
  • The purpose of this study was to evaluate the possibile clinical application of electroplating to increase diameter of an orthodontic wire, through examining the change of physical properties. The diameter of stainless steel orthodontic wire was increased from 0.016 inch to 0.018 inch by electroplating in a bath of nickel sulfate 100g/L, nickel chloride 60g/L, boric acid 30g/L, and sodium chloride 50g/L, under the conditions of 1.7V, $25\~29^{\circ}C\;and\;3.1\~3.3pH$. During the electroplating, the rate of diameter increase was measured every minute. To investigate uniformity, the diameter was measured at three different locations of each wire specimen aster electroplating. An X-ray diffraction test was performed to analyze the nature of the electroplated metal. Following heat treatment to improve adhesion between the wire and electroplated metal, a three-point bending test was conducted to compare stiffness, field strength, and ultimate strength among four wire groups; 0.016 inch, electroplated 016, electroplated and heat-treated 016, and 0.018 inch wires. Through the comparison of each wire group, following results were obtained. 1. In the load-deflection graph, the curve of the electroplated group was Placed between that of the 0.016 inch group and the 0.018 inch group, and the owe was closer to the 0.018 inch group by heat treatment. 2. In the electroplated and heat-treated 016 wire group, the values of stiffness, yield strength and ultimate strength showed higher tendency than in the original 0.016 Inch group. Stiffness and ultimate strength showed statistically significant differences between two groups. 3. Stiffness, yield strength, and ultimate strength of electroplated wire presented lower values than those of 0.018 inch wire group. 4. Stiffness, yield strength, and ultimate strength of electroplated and heat-treated wire showed higher tendency than those of electroplated wire group, and ultimate strength showed statistically significant difference between two groups. 5. After electroplating, the difference in diameter between the three locations was within $0.1\~0.3\%$ variation, and showed no statistical significance.

Capsule Train Dynamic Model Development and Driving Characteristic Analysis Considering the Superconductor Electrodynamic Suspension (초전도 유도 반발식 부상특성을 고려한 캡슐트레인 동특성 해석 모델 구축 및 주행 특성 분석)

  • Lee, Jin-Ho;Lim, Jungyoul;You, Won-Hee;Lee, Kwansup
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.7
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    • pp.38-45
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    • 2020
  • A magnetically levitating capsule train, which runs inside the sub-vacuum tube, can reach ultra-fast speeds by dramatically reducing the aerodynamic drag and friction. The capsule train uses the superconductor electrodynamic suspension (SC-EDS) method for levitation. The SC-EDS method has advantages, such as a large levitation gap and free of gap control, which could reduce the infra-construction cost. On the other hand, disadvantages, such as the large variation of the levitation-guidance gap and small damping characteristics in levitation-guidance force, could degrade the running stability and ride comfort of the capsule train. In this study, a dynamic analytical model of a capsule train based on the SC-EDS was developed to analyze the running dynamic characteristics. First, as important factors in the capsule train dynamics, the levitation and guidance stiffness in the SC-EDS system were derived, which depend non-linearly on the velocity and gap variation. A 3D dynamic analysis model for capsule trains was developed based on the derived stiffness. Through the developed model, the effects of the different running speeds on the ride comfort were analyzed. The effects of a disturbance from infrastructure, such as the curve radius, tube sag, and connection joint difference, on the running stability of the capsule train, were also analyzed.

A Study on the Simple Design Method of Semi-Rigid Connection with Angle in Steel Structure (강구조에서 ㄱ형강을 이용한 반강접 접합의 간편 설계)

  • Heo, Myong-Jae;Kim, Hong-Geun;Choi, Won-Gu
    • Journal of Korean Society of Steel Construction
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    • v.23 no.3
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    • pp.261-273
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    • 2011
  • Recently, the demands for steel frame are increasing because of the trend and due to the demand for bigger and higher buildings. In the analysis of typical steel frame, connections are based on the idealized fixed or pinned connection. A fixed connection assumes that the relative angle of each member before deformation is the same after the transformation. Therefore, the stiffener reinforces the connection to sufficient rigidity and stability of the panel zone. In the economical aspect, however, the necessity of connection that the stiffener reinforcement has omitted is increasing due to the excessive production as well as labor costs of connection. In contrast, pinned connection is assumed that bending moments between the beams and columns do not transfer to each member. This is easy to make in the plant and the construction is simple. However, the structural efficiency is reduced in pinned connection because connection cannot transfer moments. The introduction of this semirigid process can decide efficient cross-sectional dimensions that promote ease in the course of structural erection, as performed by members in the field-a call for safety in the entire frame. Therefore, foreign countries exert efforts to study the practical behavior and the results are applied to criterion. This paper analyzes the semirigid connection of domestic steel by design specifications of AISC/LRFD and make data bank that pertain to each steel. After wards, the results are compared to those of idealized connection; at the same time, this paper presents a design method that matches economic efficiency, end-fixity, and rotational stiffness.

Evaluation of Particle Size Effect on Dynamic Behavior of Soil-pile System (모래 지반의 입자크기가 지반-말뚝 시스템의 동적 거동에 미치는 영향 평가)

  • Yoo, Min-Taek;Yang, Eui-Kyu;Han, Jin-Tae;Kim, Myoung-Mo
    • Proceedings of the Korean Geotechical Society Conference
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    • 2010.03a
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    • pp.188-197
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    • 2010
  • This paper presents experimental results of a series of 1-g shaking table model tests performed on end-bearing single piles and pile groups to investigate the effect of particle size on the dynamic behavior of soil-pile systems. Two soil-pile models consisting of a single-pile and a $4{\times}2$-pile group were tested twice; first using Jumoonjin sand, and second using Australian Fine sand, which has a smaller particle size. In the case of single-pile models, the lateral displacement was almost within 1% of pile diameter which corresponds to the elastic range of the pile. The back-calculated p-y curves show that the subgrade reaction of the Jumoonjin-sand-model ground was larger than that of the Australian Fine-sand-model ground at the same displacement. This phenomenon means that the stress-strain behavior of Jumoonjin sand was initially stiffer than that of Australian Fine sand. This difference was also confirmed by resonant column tests and compression triaxial tests. And the single pile p-y backbone curves of the Australian fine sand were constructed and compared with those of the Jumoonjin sand. As a result, the stiffness of the p-y backbone curves of Jumunjin sand was larger than those of Australian fine sand. Therefore, using the same p-y curves regardless of particle size can lead to inaccurate results when evaluating dynamic behavior of soil-pile system. In the case of the group-pile models, the lateral displacement was much larger than the elastic range of pile movement at the same test conditions in the single-pile models. The back-calculated p-y curves in the case of group pile models were very similar in both sands because the stiffness difference between the Jumoonjin-sand-model ground and the Australian Fine-sand-model ground was not significantly large at a large strain level, where both sands showed non-linear behavior. According to a series of single pile and group pile test results, the evaluation group pile effect using the p-multiplier can lead to inaccurate results on dynamic behavior of soil-pile system.

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The Usefulness of Liver Fibroscan Test Using Ultrasound Image (초음파영상을 이용한 간탄력도 검사의 유용성)

  • An, Hyun;Lee, Jin-Soo;Im, In-Chul;Yang, Sung-Hee
    • Journal of the Korean Society of Radiology
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    • v.11 no.4
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    • pp.205-212
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    • 2017
  • Chronic diffuse hepatopathy is one of the important clinical tasks to reduce mortality and morbidity due to liver cirrhosis, liver failure, and liver cancer. The purpose of this study was to evaluate the criteria for predicting liver and chronic liver disease using Fibroscan based on ultrasound diagnosis. Serum and liver stiffness measurement(kPa) were analyzed in 280 patients and cut-off values of liver stiffness measurement for predicting fatty liver and chronic diffuse hepatopathy were determined using ROC curve analysis. Bilirubin and PT(prothrombin time) were not related to disease prediction(p=0.243, p=0.115). Serum glucose and triglyceride levels were significantly higher in the liver (p<0.05). The cut-off value for predicting chronic diffuse hepatopathy was determined as 10.3 kPa(AUC 0.98, sensitivity 94.94%, specificity 94.93%) in the order of control group, fatty liver and chronic diffuse hepatopathy. Therefore, it will be used as a primary tool for the diagnosis of chronic liver disease patients with quantitative evaluation.

Estimation of Rockbolt Integrity by Using Non-Destructive Testing Techniques(I) -Numerical and Experimental of Applicability- (비파괴 시험기법을 이용한 록볼트의 건전도 평가(I) -수치해석 및 실험적 적용성 평가-)

  • Lee, Jong-Sub;Lee, Yong-Jun;Eom, Tae-Won;Han, Shin-In;Lee, In-Mo
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.8 no.1
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    • pp.3-12
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    • 2006
  • The purpose of this study is to describe the Non-Destructive Testing(NDT) of the rockbolt and investigate the applicability of the NDT methods to estimate the integrity of the rockbolt. To examine the rockbolt integrity including rockbolt itself and grouting material, two methods are adopted: numerical and experimental methods. In the numerical method, the numerical code DISPERSE is used to analyze the dispersion of the rockbolt. The dispersion curve shows the effects of the thickness and stiffness of grouted materials on the embedded rockbolt. Therefore, the optimal frequency for the integrity test of the rockbolt is obtained: 20~120kHz in L(1,0) mode. In the experimental methods, destructive and non-destructive tests are carried out in a laboratory. In the non-destructive test, the low frequency mode generated by an impact and t he high frequency mode generated by an ultrasonic transducer seem to characterize the rockbolt condition readily. The experimental results show that the guided waves attenuate more significantly when the stiffness of the grouted material increases and/or the zone of the defect increases. Meanwhile, the ultimate capacity of rockbolt was evaluated through the pull-out tests and is compared to the NDT results. This study demonstrates that the NDT is a valuable tool for the rockbolt integrity evaluation.

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Nonlinear Subgrade Reaction Analysis of the Soil-Pile System for Mooring Dolphin Structures (계류식 돌핀구조물에 대한 지반-말뚝계의 비선형 지반반력 해석)

  • 오세붕;이진학;이상순;김동수;정태영
    • Journal of the Korean Geotechnical Society
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    • v.15 no.2
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    • pp.3-16
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    • 1999
  • The objective of BMP( Barge Mounted Plant) project is to construct plants on mooring floating structures at sea. To analyze the pile behavior under mooring dolphins, generally, axial or lateral behavior of soil-pile system is evaluated by using a nonlinear subgrade reaction method which models the pile as a structural element and the soil as series of nonlinear springs along the depth. As a result, load-displacement curves at pile head can be solved by finite difference method and the equivalent stiffness of bottom boundaries of dolphin structure is evaluated. In this study off-shore site investigation was performed on the marine area of Koje Island and axial and lateral load transfer curves of the ground were modeled with depth. The subgrade reaction analysis was performed for piles under axial or lateral loadings, and the required penetration depth and section of the pile were determined. Subsequently, the spring boundaries under the dolphin structure could be modeled from the calculated load-displacement curve and then the dynamic response of the dolphin structure was analyzed reasonably by considering ground conditions. The analysis considering the stiffness of the soil-pile system has resulted in larger displacement amplitudes than those for rigid foundations. Furthermore, moment distributions of the casing were dependent on the soil-pile system so that deformable foundation induces the larger moment of top section of casing and the smaller moment of pile head.

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