• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2010년 춘계학술대회논문집
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• pp.542-547
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• 2010

Recently, thanks to advanced computational power and numerical techniques, it is made possible to analyze the flow around moving bodies using computational fluid dynamics techniques. In those simulations, moving mesh techniques should be able to represent both the body motion and boundary deformation which are frequently encounterd in fluid-structure interaction and/of six degree-of-freedom problems. There are several moving mesh techniques such as the Laplacian operator based, tension spring based and elastic deformation based methods. In the present study, the Laplacian operator based method was utilized and the results were validated. For the validation, the flow around an oscillating two-dimensional cylinder was simulated and analyzed.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권3호
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• pp.1063-1075
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• 2022

In recent years, container techniques have been broadly applied to cloud computing systems to maximize their efficiency, flexibility, and economic feasibility. Concurrently, studies have also been conducted to ensure the security of cloud computing. Among these studies, moving-target defense techniques using the high agility and flexibility of cloud-computing systems are gaining attention. Moving-target defense (MTD) is a technique that prevents various security threats in advance by proactively changing the main attributes of the protected target to confuse the attacker. However, an analysis of existing MTD techniques revealed that, although they are capable of deceiving attackers, MTD techniques have practical limitations when applied to an actual cloud-computing system. These limitations include resource wastage, management complexity caused by additional function implementation and system introduction, and a potential increase in attack complexity. Accordingly, this paper proposes a software-defined MTD system that can flexibly apply and manage existing and future MTD techniques. The proposed software-defined MTD system is designed to correctly define a valid mutation range and cycle for each moving-target technique and monitor system-resource status in a software-defined manner. Consequently, the proposed method can flexibly reflect the requirements of each MTD technique without any additional hardware by using a software-defined approach. Moreover, the increased attack complexity can be resolved by applying multiple MTD techniques.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.68-74
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• 2011

Recently, thanks to the advanced computational power and numerical methods, it is made possible to analyze the flow around moving bodies using computational fluid dynamics techniques. In those simulations, moving mesh techniques should be able to represent both the body motion and boundary deformation, which are frequently encountered in fluid-structure interaction and/or six degree-of-freedom problems. In the present study, the staggered loosely coupling algorithm was used for fluid-structure interaction and the Laplacian operator based technique was used for moving mesh. For the verification of the developed computational method, the flow around a two-dimensional cylinder was simulated and analyzed.

• 한국응급구조학회지
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• 제24권1호
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• pp.77-84
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• 2020

Purpose: This study was conducted to determine effective chest compression methods that could be used when performing cardiopulmonary resuscitation in rocking boats. Methods: Tests were conducted for four minutes using manual and mechanical chest compressions on two mannequins, placed in boats, and moving at a speed of 35km/hours on calm sea surfaces with wave heights of 0.5m and wind speeds of 2-3m/s (testing for two minutes, followed by rest, then a second round of testing for two minutes). To compare the quality of the chest compressions, data were analyzed using mannequins (Resusci Anne Q-CPR, Laerdal, Norway) and then statistically processed. Results: When chest compressions were administered in the moving rescue boat, an accuracy analysis showed that the pressure speed of the hand and mechanical techniques were normal, h owever, the pressure depth accuracies were 49.04% for manual techniques and 0% for mechanical techniques. The relaxation accuracies during compressions were 2.07% for manual techniques and 95.4% for mechanical techniques. Conclusion: When administering chest compressions in rocking rescue boats, mechanical rather than manual techniques should be preferentially considered.

• 한국컴퓨터정보학회논문지
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• 제11권1호
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• pp.87-96
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• 2006

선택을 추정은 질의 최적화를 위한 기법중의 하나이다. 이동객체에 대한 기존 선택율 추정 기법은 시간에 따른 이동객체의 위치 변화를 요약 정보에 반영하지 못하며. 또한 기존 공간 요약 정보를 확장하여 이용함으로써 선택율 추정시 많은 에러를 발생시키고 있다. 기존 기법들이 이동객체의 위치 정보 변화를 요약 정보에 반영하기 위해서는 요약 정보를 자주 재생성해야 하며, 그러므로 전체 데이터베이스를 자주 스캔해야 하는 문제점을 갖고 있다. 따라서 이 논문에서는 이동객체의 현재 질의에 대한 선택을 추정 기법을 개발하기 위하여 쿼드 트리 기반의 히스토그램 기법을 제안하였다. 또한 제안된 기법의 구현과 평가를 통해 제안된 기법의 성능을 분석하였다. 이 논문에서 제안된 기법은 차량 추적 시스템, 위치 기반 서비스, 응급 구조 서비스, 그리고 텔레매틱스 서비스 등과 같은 연속적으로 위치를 변경하는 이동객체의 정보를 실시간으로 관리하고 검색하는 응용분야에 활용 가능할 것이다.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1998년도 Proceedings of International Workshop on Advanced Image Technology
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• pp.35-40
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• 1998

This paper describes an automatic recognition method of contents in moving images. The recognition process is carried out by the following two steps. At first, camera works in moving images are analyzed and moving objects are extracted from the moving images. Next, the motion of the object is recognized by pre-procured knowledge. These techniques will be applied to a construction of an efficient image database.

• Structural Engineering and Mechanics
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• 제58권6호
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• pp.1087-1107
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• 2016

A method of damage detection based on the moving harmonic excitation and continuous wavelet transforms is presented. The applied excitation is used as a moving actuator and its frequency and speed parameters can be adjusted for an amplified response. The continuous wavelet transforms, CWT, is used for cracks detection based on the resulting amplified signal. It is demonstrated that this identification procedure is largely better than the classical ones based on eigenfrequencies or on the eigenmodes wavelet transformed. For vibration responses, free and forced vibration analyses of multi-cracked beams are investigated based on both analytical and numerical methodological approaches. Cracks are modeled through rotational springs whose compliances are evaluated using linear elastic fracture mechanics. Based on the obtained forced responses, multi-cracks positions are accurately identified and the CWT identification can be highly improved by adjusting the frequency and the speed excitation parameters.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.118.5-118
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• 2001

This paper describes an image processing method for inspecting the surface outlook of high speed moving plates. Noise free image and a new real time processing methods are required to inspect the surface outlook of the high speed moving plates in real time. It is difficult to get a noise free image due to a signal noise, a light noise and background image in typical industrial factory. Thus, pre-processing techniques should be required to get a good image and produce so many time steps to proceed the image data. The objective of this research is to get image on the surface of the moving plates with a speed of 1m/sec and to detect some defaults on the surface image. So, the pre-processing techniques ...

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1492-1499
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• 2010

This paper is intended as an development of moving load simulation techniques. The concern with dynamic problem of railway bridge caused by the moving train loads has been growing. Over the past few years, several studies have been made on dynamic stability of railway bridge analytically. But very few attempts have been made at experimental research. From the dynamic stability view point, the moving train loads simulation test is revolutionary idea. It can be replace restrictive filed test with new laboratory test. This study investigates minimum specifications of hardware and basic parameters. it is used 39m girder and 4 actuators for experimental verification.

• 융합보안논문지
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• 제8권4호
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• pp.97-104
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• 2008

최근 이동 객체의 위치 데이터를 이용하기 위한 무선 측위 기술과 모바일 컴퓨팅 기술이 급속도로 발전하였다. 이동 객체의 수가 많고 위치 획득 간격이 짧을수록 위치 데이터가 급격히 늘어나기 때문에 대용량의 위치 데이터 처리가 가능해야 하며, 위치 기반 서비스를 위한 다양한 시공간 인덱싱을 지원해야 하고, 또한 이동 객체의 불확실성 문제를 해결할 수 있어야 한다. 따라서, 본 논문에서는 이동 객체의 위치 데이터를 효과적으로 갱신하면서 현재 데이터와 과거 데이터의 인덱싱을 지원하는 색인 구조로 3DR-tree 기법을 활용하여 색인시 노드간의 겹침을 보완하고 사장 공간을 줄이는 Rend 3DR-tree 기법을 제안한다.