• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.31-36
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• 2006

우리나라의 경우 선박조종시뮬레이션을 이용한 선박 통항의 안전성 평가는 흔히 목표점 혹은 목표선 분석으로 이뤄지고 있다. 이 논문에서는 선박조종시뮬레이션 결과에 대하여 목표점 혹은 목표선 분석과 연속분석을 각각 실시하고 이들을 비교 ${\codt}$ 검토하여 각각에 대한 유효성을 제시하고 아울러 각각의 선박의 위치에서 항로 중심에서의 거리가 아닌, 항로경계까지의 최근접거리를 근접도 평가의 한 방법으로 제시하였다.

• 대한기계학회논문집A
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• 제32권10호
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• pp.831-835
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• 2008

We present a continuous electrical cell lysis chip, using a DC bias voltage to generate the focused high electric field for cell lysis as well as the electroosmotic flow for cell transport. The previous cell lysis chips apply an AC voltage between micro-gap electrodes for cell lysis and use pumps or valves for cell transport. The present DC chip generates high electrical field by reducing the width of the channel between a DC electrode pair, while the previous AC chips reducing the gap between an AC electrode pair. The present chip performs continuous cell pumping without using additional flow source, while the previous chips need additional pumps or valves for the discontinuous cell loading and unloading in the lysis chambers. The experimental study features an orifice whose width and length is 20 times narrower and 175 times shorter than the width and length of a microchannel. With an operational voltage of 50 V, the present chip generates high electric field strength of 1.2 kV/cm at the orifice to disrupt cells with 100% lysis rate of Red Blood Cells and low electric field strength of 60 V/cm at the microchannel to generate an electroosmotic flow of $30{\mu}m/s{\pm}9{\mu}m/s$. In conclusion, the present chip is capable of continuous self-pumping cell lysis at a low voltage; thus, it is suitable for a sample pretreatment component of a micro total analysis system or lab-on-a-chip.

• 대한물리치료과학회지
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• 제10권1호
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• pp.7-17
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• 2003

The purpose of this study was to investigate the effect of the involved lower limb weight bearing training on symmetrical weight supporting rate improvement and gait characteristics of patients with hemiplegia including their gait velocity, cadence, stride length, step length of the non affected side, step length of the affected side, foot angle of the non affected side, foot angle of the affected side, base of support, and so on. The subject of the study was 28 men and women patients with hemiplegia from 22 to 77 age, among patients who doctor diagnosed as hemiplegia due to stroke or traumatic brain injury, were possible to do independent gait more than 45m without others assistance, the flexion contracture of hip pint was less than $15^{\circ}$, did not have contracture for knee pint and one more than $5^{\circ}$ for ankle joint, did not have contraindication for exercise or gait did not show visual defect due to brain injury. The patients, the subject of the study, were classified into 14 patients of treatment. group applying continuous involved weight bearing with general therapeutic exercise and 14 patients of control group applying general therapeutic exercise, and then analyzed their gait before and after exercise. Temporal distance gait analysis(Boening, 1977) was used to analyze their gait, and ink foot-print was applied as one of measurement methods. However, it was statistically signifiant in the change rate(%) of gait characteristics, and treatment group's patients with hemiplegia had been highly changed in gait characteristics in comparison with control group. From the above-mentioned results, could find that continuous involved weight bearing training for patients with hemiplegia was effective to improve their gait ability and it could increase the ability in comparison with general exercise.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2000년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall 2000
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• pp.184-191
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• 2000

In this research, a numerical model is developed for analysis of buried pipelines considering longitudinal permanent ground deformation(PGD) due to liquefaction induced lateral spreading. Buried pipelines and surrounding soil are medeled as continuous pipelines using the beam elements and a series of elasto-plastic springs uniformly distributed along the pipelines, respectively. Idealized various PGD patte군 based on the observation of PGD are used as a loading configuration and the length of the lateral spread zone is considered as a loading parameter. Numerical results are verified with other research results and efficient applicability of developed procedure is shown. Analyses are performed by varying different parameters such as PGD pattern, pipe diameter and pipe thickness. Results show that response of buried pipelines are more affected by pipe thickness than pipe diameter. Finally, the critical length of the lateral spread zone and the critical magnitude of PGD which cause yielding, local buckling or tension failure are proposed for the steel pipe which are normally used in Korea.

• Structural Engineering and Mechanics
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• 제33권2호
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• pp.239-255
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• 2009

In the companion paper, a simple but effective analysis procedure termed an Improved Modal Pushover Analysis (IMPA) is proposed to estimate the seismic capacities of multi-span continuous bridge structures on the basis of the modal pushover analysis, which considers all the dynamic modes of a structure. In contrast to previous studies, the IMPA maintains the simplicity of the capacity-demand curve method and gives a better estimation of the maximum dynamic response in a bridge structure. Nevertheless, to verify its applicability, additional parametric studies for multi-span continuous bridges with large differences in the length of adjacent piers are required. This paper, accordingly, concentrates on a parametric study to review the efficiency and limitation in the application of IMPA to bridge structures through a correlation study between various analytical models including the equivalent single-degree-of-freedom method (ESDOF) and modal pushover analysis (MPA) that are usually used in the seismic design of bridge structures. Based on the obtained numerical results, this paper offers practical guidance and/or limitations when using IMPA to predict the seismic response of a bridge effectively.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2007년도 정기 학술대회 논문집
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• pp.795-800
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• 2007

In the previous study, a simple but effective analysis procedure, named as an Improved Modal Pushover Analysis (IMPA) was proposed to estimates the seismic capacities of multi-span continuous bridge structures, on the basis of the modal pushover analysis which considers all the dynamic modes of a structure. Differently from other previous studies, IMPA maintains the simplicity of the capacity-demand curve method and also gives a better estimation of the maximum dynamic response of a structure. Nevertheless, its applicability has never been approved for multi-span continuous bridges with large differences in the length of their adjacent piers. This paper, accordingly, concentrates on a parametric study to verify the efficiency and limitation in application of IMPA through a correlation study between various analytical models including the Equivalent Single Degree Of Freedom (ESDOF) and Modal Pushover Analysis (MPA) usually used in the seismic design of structures. Based on the obtained numerical results, this paper introduces a practical guidance and/or limitation for using IMPA to predict the seismic response of a bridge effectively.

• Structural Engineering and Mechanics
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• 제17권2호
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• pp.245-266
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• 2004

Incremental launching method is one of the highly competitive techniques for construction of concrete bridges. It avoids costly and time consuming form work and centralizes all construction activities in a small casting yard, thus saving in cost and time against conventional bridge construction. From the quality point of view, it eliminates the uncertainty of monolithic behaviour by allowing high repetitiveness and industrial environment. But, from analysis and design point of view, the most characteristic aspect of incrementally launched bridges is that, it has to absorb the stresses associated with the temporary supports that are gradually taken on by the deck during its launch. So, it is necessary to analyse the structure for each step of launching which is a tedious and time consuming process. Effect of support settlements or temperature variation makes the problem more complex. By using transfer matrix method, this problem can be handled efficiently with minimal computational effort. This paper gives insight into method of analysis, formulation for optimization of the structural system, effect of support settlement and temperature gradient, during construction, on the stress state of incrementally launched bridges.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1999년도 춘계학술대회 논문집
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• pp.442-449
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• 1999

Due to temperature variations, considerable longitudinal rail forces and displacements may develop in continuous welded rail(CWR) track on long-span bridges or viaducts. Excessive relative displacements between sleepers and ballast bed may disturb the stable position of the track in the ballast which results in a lower frictional resistance. Generally, these problems are solved by installing rail expansion devices. However the application of expansion devices in high-speed tracks on existing bridges, as a means to prevent excessive longitudinal displacements and forces, is not attractive method due to comfort, safety and maintenance aspects. An alternative and very effective solution is possibly the use of so-called zero longitudinal restraint(ZLR) fastenings over some length of the track. The calculations, carried out in this respect, show a considerable reduction of track displacements, track forces, and the relative sleeper/ballast displacements. This reduction depends on the length over which these fastenings are installed. In this paper calculations of the longitudinal displacments and forces in a CWR track and substructure resulting from thermal, mechanical and kinematical loads were carried out using the FEM analysis program LUSAS

• 대한치과교정학회지
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• 제41권4호
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• pp.237-254
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• 2011

설측의 연속호선과 분절호선의 3차원 유한요소 모델에서 레버암의 길이와 미니스크류의 위치를 달리하여 전치부 후방 견인 시의 변위 양상을 비교하였다. 구개 경사면 견인 시, 두 호선 공히 레버암이 짧을수록 전치부의 설측 경사 이동을, 20 mm인 경우 중절치의 치체 이동 및 견치의 치근 이동 양상을 나타냈다. 정중구개봉합부 견인 시의 변위양상은 구개 경사면의 경우와 유사하였으나, 레버암이 20 mm인 두 호선에서 절치의 치체 이동 및 연속호선에서 전치부의 함입 소견을 보였다. 호선 종류에 관계없이 레버암이 길어질수록 절치의 정출은 감소하였고, 구개 경사면에서의 견인인 경우와 함께 견치의 협측 변위가 증가하였으며, 분절호선에서 변위량이 많았다. 연속호선상의 제2소구치는 근심 경사 이동 및 함입 소견을, 대구치는 레버암이 길수록 원심 이동 및 협측 변위를 나타낸 반면, 분절호선상의 구치부도 3차원적 이동 양상을 나타냈으나 변위량은 미미하였다. 전치부 후방 견인 시 레버암 작용에 의해 절치의 경사 이동과 견치의 측방 이동 경향이 있었으며, 치체 이동을 위해서는 약 20 mm의 레버암을 추천할 수 있다. 또한 호선의 종류가 치열 변위 양상 및 변위량에 차이를 나타냈다.

• The Korean Journal of Pain
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• 제25권3호
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• pp.151-154
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• 2012

Background: The aim of this study was to document the optimal spacing of two cannulae to form continuous strip lesions and maximal surface area by using water-cooled bipolar radiofrequency technology. Methods: Two water-cooled needle probes (15 cm length, 18-gauge probe with 6 mm electrode tip) were placed in a parallel position 10, 20, 24, 26, and 28 mm apart and submerged in egg white. Temperatures of the probes were raised from $35^{\circ}C$ to $90^{\circ}C$ and the progress of lesion formation was photographed every 1 minute with the increase of the tip temperature. Approximately 30 photographs were taken. The resultant surface areas of the lesions were measured with the digital image program. Results: Continuous strip lesions were formed when the cannulae were spaced 24 mm or less apart; monopolar lesions around each cannula resulted if they were spaced more than 26 mm apart. Maximal surface areas through the formation of continuous strip lesion were 221 $mm^2$, 375 $mm^2$, and 476 $mm^2$ in 10, 20, and 24 mm, respectively. Summations of maximal surface area of each monopolar lesions were 394 $mm^2$ and 103 $mm^2$ in 26 and 28 mm, respectively. Conclusions: Water-cooled bipolar Radiofrequency technology creates continuous "strip" lesions proportional in size to the distance between the probes till the distance between cannulae is 24 mm or less. Spacing the cannulae 24 mm apart and treating about $80^{\circ}C$ for 24 minutes maximizes the surface area of the lesion.