• 자동차안전학회지
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• 제9권2호
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• pp.26-32
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• 2017

This paper presents the lateral stability criteria for integrated chassis control. To determine the intervention timing of chassis control system, the lateral stability criteria is needed. The proposed lateral stability criteria is based on velocity-yawrate gain domain to determine whether vehicle is stable. If the yawrate gain violates the proposed criteria, the stability of the vehicle is considered as unstable. Characteristic velocity and critical velocity are employed to distinguish lateral stability criteria. The inside of the two boundaries is stable and the outside is unstable. If yawrate gain of vehicle violates the lateral stability criteria, the chassis control begin to intervene. To validate the lateral stability criteria, both computer simulations and vehicle test are conducted with respect to circular turn scenario. The proposed lateral stability criteria makes it possible to reduce intervention of chassis control system.

• 한국해양공학회지
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• 제34권2호
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• pp.55-65
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• 2020

A review of the 2nd generation of intact stability by the International Maritime Organization is performed. The main issues with the new stability criteria are reviewed. In particular, the physical background and related mathematical formulations of the pure loss of stability and parametric roll are summarized. Based on a literature review, benchmark calculation results for 17 different types of ships are discussed, and the final results are in excellent agreement with our physical expectations. Some relatively serious design problems are found in the application of the new stability criteria to sample ships built in Korea, and possible technical solutions are proposed, which have to be improved in the coming years.

• Wind and Structures
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• 제21권4호
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• pp.407-424
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• 2015

To explore the favorable structural system of cable-stayed bridges with ultra-kilometer main span, based on a fully self-anchored cable-stayed bridge with 1400 m main span, a partially earth-anchored cable-stayed bridge scheme with the same main span is designed. Numerical investigation on the dynamic characteristics, aerostatic and aerodynamic stability of both two bridge schemes is conducted, and the results are compared to those of a suspension bridge with similar main span, and considering from the aspect of wind stability, the feasibility of using partially earth-anchored cable-stayed bridge in super long-span bridges with ultra-kilometer main span is discussed. Moreover, the effects of structural design parameters including the length of earth-anchored girder, the number of auxiliary piers in side span, the height and width of girder, the tower height etc on the dynamic characteristics, aerostatic and aerodynamic stability of a partially earth-anchored cable-stayed bridge are analyzed, and their reasonable values are proposed. The results show that as compared to fully self-anchored cable-stayed bridge and suspension bridge with similar main span, the partially earth-anchored cable-stayed bridge has greater structural stiffness and better aerostatic and aerodynamic stability, and consequently becomes a favorable structural system for super long-span bridges with ultra-kilometer main span. The partially earth-anchored cable-stayed bridge can achieve greater stiffness and better wind stability under the cases of increasing the earth-anchored girder length, increasing the height and width of girder, setting several auxiliary piers in side span and increasing the tower height.

• 한국방재학회 논문집
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• 제5권1호
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• pp.45-53
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• 2005

우리나라와 같이 홍수시 단기간에 걸쳐 유량이 급증하는 경우 유속에 의한 교량 기초의 급격한 세굴은 예상치 못한 교량 붕괴사고를 초래할 수 있다. 세굴은 교량의 수명이나 안정성 유지에 중요한 요인으로 작용한다. 국내의 경우, 매년 약 100여 개의 크고 작은 교량이 세굴로 인하여 붕괴 및 손상을 입고 있음에도 불구하고 장 단기간에 걸친 세굴보호대책은 충분하지 않은 상태이며, 세굴의 진행정도도 얼마나 심각한 상태인지 완전히 파악되지 않은 실정이다. 이 연구에서는 우리나라 중부지역의 중 소하천을 택하여 세굴 현황 및 세굴 보호공에 관한 실태를 조사하였다. 조사 결과 교량 288개소 중에서 보호공이 있는 교량수는 전체교량의 7.3%에 불과하여 세굴에 대한 대비가 거의 없는 것으로 나타났다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2003년도 사면안정학술발표회
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• pp.45-52
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• 2003

Construction and extension of road by industrialization are increasing. According to this, construction of large cutting slope is increasing. Therefore, many methods for slope stability by this are applied. Failure happens according to dip and dip direction of slope. It is actuality that is connoting unstable element. This slope include coaly shale. Stability of slope failure this study takes place by road extension running examination for stability property calculate. Use this and examined stability about stereographic projection and wedge failure. Apply suitable reinforcement countermeasure about unstable cutting slope and analyzed stability. Wish to consider effective and robust processing plan of great principle earth and sand side securing stability. Hereafter with these data, is going to utilize in reinforcement and failure prevention.

• Wind and Structures
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• 제6권2호
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• pp.151-164
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• 2003

On the basis of the first Lyapunov stability theory, this paper develops a dynamic stability criterion for elastic structural systems under arbitrary dynamic loads, and shows the stability criterion using energy variation. After the dynamic stability criterion is validated through a classic example, it is used for the dynamic stability investigation of practical guyed masts under random wind loads. The criterion is reliable, simple and of advantage for structures with large number of elements and nodes. The slack guys and internal resonance between guys and mast are two main factors which induces the dynamic instability of guyed masts, at the same time, some dynamic stability characteristics of guyed masts are found.

• Journal of Pharmaceutical Investigation
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• 제35권5호
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• pp.333-336
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• 2005

The objective of this study was to investigate the stability of tetracycline HCl on encapsulation into and inside reverse micelles. To do so, tetracycline HCl was first mixed with cetyltrimethylammonium bromide, water and ethyl formate to make reverse micelles. The degradation kinetics of tetracycline HCl inside the reverse micelles was then assessed by scrutinizing its stability data. Under our experimental conditions, the reverse micelles formed spontaneously in absence of any mixing devices. During the preparation of the reverse micelles, however, considerable portions of tetracycline HCl underwent a chemical reaction (e.g., epimerization). For instance, $51.4{\pm}0.6%$ of an initial concentration of tetracycline HCl was transformed into a degradation product. Once dissolved inside the reverse micelles, the degradation of tetracycline HCl followed an exponential decay pattern. The plot of log{the degradation rate of tetracycline HCl} versus log{tetracycline HCl concentration} made it possible to determine the order of degradation reaction and rate constant. It was proven that the degradation of tetracycline HCl inside the reverse micelles followed a first order kinetics with a rate constant of 0.0027 $hour^{-1}$. Meriting further investigation might be formulation studies to stabilize tetracycline HCl on encapsulation into and inside the reverse micelles.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.993-998
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• 2002

Ultra precision processing technology is the field which is seriously protected its technology by advanced nations. Because of this reason, this technology is very difficult to supply for domestic companies, also domestic companies are revealed the limit of technology development by itself. And then, those are depend on the technology development of advanced nation, domestic companies are not conquer application step with already developed parts. Of course, some cases of its research are succeed. those are included element technology, system technology and so on, for development of ultra precision processing system. To conquer technology holding ultra precision processing accuracy of no level, active research are needed. In this paper, stability of ultra precision cutting unit is analyzed, this unit is the kernel unit in ultra precision processing machine. According to alteration of shape and material about hinge, stability investigation is performed Through this stability investigation, trial and error is reduced in design and manufacture, at the same time, we are accumulated foundation data for un it control.

• 한국지구물리탐사학회:학술대회논문집
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• 한국지구물리탐사학회 1999년도 제2회 학술발표회
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• pp.217-239
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• 1999

일반적으로 사면에 대한 조사방법은 지표지질조사를 실시하여 불연속면의 정보를 획득하는 것이 보편화 된 방법이나 제한된 영역의 정보만을 획득하게 되는 문제점을 가지게 된다. 일반적으로 절취사면에서 활동면 또는 활동가능면을 추정하는 방법으로 토모그래피, 전기비저항탐사, 탄성파 탐사와 같은 지구물리탐사 방법을 이용하나 최근에 사용된 카메라 장치를 이용하는 방법은 시추공벽의 화상을 촬영하여 직접 육안으로 확인 할 수 있는 방법으로 다른 방법들에 비해 보다 확실한 방법이라고 생각된다. 그러므로 본 논문은 고속도로 현장에서 붕괴가 발생된 사면의 활동면 위치를 파악하기 위해 총 4 개공의 시추를 실시하였고 BIPS(Borehole Image Processing System) 장비를 도입하여 활동면의 위치를 파악하였다. 그 결과, 철탑구간은 지표에서 20m 하부구간까지 암질이 매우 불량하고 점토층이 충전된 파쇄대층이 존재하고 철탑좌측구간은 이미 인장균열이 발생되었으며 점토층이 충전된 층리면 존재하고 층리면은 사면방향으로 경사져 붕괴가능성이 클 것으로 나타났다. BIPS 결과는 사면안정대책 방안에 수립하는 데 이용하여 억지말뚝으로 사면보강공을 선정하였다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2008년도 정기총회 및 학술발표대회
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• pp.561-564
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• 2008

Rock slope had been slope failure due to geological and physical things over time. In this paper, it discusses rock slope stability analysis which was concerned about additional slope failure located near the Andong-si. Initially, achieved basic geological investigation and field test about rock slope, examine the stability of rock slope by doing limit equilibrium method and stereographic projection about 5 slopes.