• Title/Summary/Keyword: Stability check

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Stability Analysis for the Deployment of Unmanned Surface Vehicles

  • Dharne, Avinash G.;Lee, Jaeyong
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.2
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    • pp.159-165
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    • 2015
  • Motion control schemes are generally classified into three categories (point stabilization, trajectory tracking, and path following). This paper deals with the problem which is associated with the initial deployment of a group of Unmanned Surface Vehicle (USVs) and corresponding point stabilization. To keep the formation of a group of USVs, it is necessary to set the relationship between each vehicle. A forcing functions such as potential fields are designed to keep the formation and a graph Laplacian is used to represent the connectivity between vehicle. In case of fixed topology of the graph representing the communication between the vehicles, the graph Laplacian is assumed constant. However the graph topologies are allowed to change as the vehicles move, and the system dynamics become discontinuous in nature because the graph Laplacian changes as time passes. To check the stability in the stage of deployment, the system is modeled with Kronecker algebra notation. Filippov's calculus of differential equations with discontinuous right hand sides is then used to formally characterize the behavior of USVs. The stability of the system is analyzed with Lyapunov's stability theory and LaSalle's invariance principle, and the validity is shown by checking the variation of state norm.

Internal Stability of Timber Framed Earth Retaining Wall (목재옹벽의 내적안정 평가에 관한 연구)

  • Lee, Kwang-Wu;Kim, Ju-Hyong;Cho, Sam-Deok
    • Journal of the Korean Geosynthetics Society
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    • v.10 no.2
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    • pp.81-89
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    • 2011
  • This paper introduces a recently developed thinning-out timber framed earth retaining wall system. Timber framed retaining walls are usually designed by using design code of gravity type retaining wall but internal stability of timber framed earth retaining walls is often neglected. In this study, it is recommended to use the design code for segmental retaining walls by National Concrete Masonry Association (NCMA, 1997) to check internal stability of timber framed earth retaining wall. Based on the several shear test results for 3 types of timber frames, a simple design chart including internal stability is suggested.

Legal Aspects for Quality Evaluation Standard of Plant Variety and Seed (식물 품종 및 종자의 품질평가 기준에 대한 규정현황)

  • 최근진
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.47
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    • pp.200-215
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    • 2002
  • There are some international standards and organization controling the quality characteristics of varieties and seeds such as UPOV, OECD, ISTA, AOSA. The National List system to check variety performance such as quality characteristics of plant varieties and seeds was established by each countries. The UPOV (International Union for the Protection of New varieties of Plant) regulates the requirement of plant variety protection that is distinctness (D), uniformity (U), stability (S) (here in after called DUS), Novelty and Denomination, and some quality characteristics are used to examine the requirement of plant variety protection by each crops. OECD (Organization for Economic Cooperation Development) seed scheme regulates the seed certification for seed trade between countries. ISTA (International Seed Testing Association) and AOSA(Association for Official Seed Analyst) regulates the seed analysis standard and methods. Most of the countries in Europe has the National List system, which check the value for cultivation and use(VCU), that is to say, variety performance such as yield, quality and stress to environment. All the seeds should be enlisted in the National List before sell the seed in their country. All the quality characteristics checked variety performance are for instance, amylose and amylopectin content in rice, molting quality, $\beta$-glucan, protein in barley, protein and sugar content in soybean, sugar and amylopectin content in corn etc. Conditions for the protection of new variety of plant are DUS. Quality characteristics may be the important characteristics and used to check DUS in crop by crop. It is very important to develop a new characteristics and establish standard method fur examine the VCU and DUS test for each crop.

A Study on the Vulnerability of Using Intermediate Language in Android: Bypassing Security Check Point in Android-Based Banking Applications (안드로이드 뱅킹 어플리케이션 내 중간언어 분석을 통한 보안 검사 지점 우회 취약점 연구)

  • Lee, Woojin;Lee, Kyungho
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.27 no.3
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    • pp.549-562
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    • 2017
  • In recent years, as the proportion of mobile banking has become bigger with daily usage of mobile banking, security threats are also increasing according to the feeling. Accordingly, the domestic banking system introduces security solution programs in the banking application and sets security check points to ensure the stability of the application in order to check whether it is always executed. This study presents a vulnerability of inactivity bypassing mobile vaccine program operation checkpoints using the intermediate language statically and dynamically analysis when decompiling the android banking applications of major banks in Korea. Also, through the results, it identifies possible attacks that can be exploited and suggest countermeasures.

Improvements of Mass Measurement Rate for Moving Objects (이송 물체의 질량 측정 속도 향샹)

  • Lee, W.G.;Kim, K.P.
    • Journal of the Korean Society for Precision Engineering
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    • v.12 no.11
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    • pp.110-117
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    • 1995
  • This study presents and algorithm and related techniques which could satisfy the important properties of check weighers and conveyor scales. The algorithm of Recursive Least Squares Regression is applied for the weighing system simulated as a dynamic model of the second order. Using the model and the algorithm, model parameters and then the mass being weighed can be determined from the step input. The performance of the algorithm was tested on a check weigher. Discussions were extended to the development of noise reduction techniques and to the lagged introduction of objects on the moving plate. It turns out that the algorithm shows several desirable features suitable for real-time signal processing with a microcomputer, which are high precision and stability in noisy environment.

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Characterization of one Time-Sequential Stereoscopic 3D Display - Part II: Quick Characterization Using Homogeneity Measurements -

  • Pierre, Boher;Thierry, Leroux;Collomb-Patton, Veronique
    • Journal of Information Display
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    • v.11 no.2
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    • pp.63-67
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    • 2010
  • In these authors’ previous paper, it was shown that grey-level stability is one of the main drawbacks of the time-sequential stereoscopic 3D display. In the present study, it was demonstrated that a videoluminance meter can be used to rapidly and easily check the quality of such display. A dedicated pattern was applied to simultaneously check the effect of the grey level on the other eye and the effect of the temporal synchronization. The results were compared with those provided by a temporal model of the display, which was obtained by measuring its temporal behavior. The visual impact of the grey-level instabilities was precisely quantified, and they were found to be a major source of imperfections for the aforementioned display.

이송 물체의 질량 측정 속도 향상

  • 이우갑;정진완;김광표
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1993.10a
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    • pp.328-332
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    • 1993
  • This study presents an algorithm and related techniques which could satisfy the important properties of check weighers and conveyor scales. The algorithm of Recursive Least Squares Regression is applied for the weighing system simulated as a dynamic model of the second order. Using the model and the algorithm, model parameters and then the mass being weighed can be determined form the step input. The performance of the algorithm was tested on a check weigher. Discussions were extended to the development of noise reduction techniques and to the lagged introduction of objects on the moving plate. It turns out that the algorithm shows several desirable features suitable for microcomputer assisted real-time signal processing, which are high precision and stability in noisy environment.

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Implement HA using Container (컨테이너를 이용한 HA 구현)

  • Kim, Dong-hwan;Gwon, Ji-Seop;Han, Sung-Hwa
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.341-343
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    • 2022
  • Information service must ensure stability in service operation. For this purpose, many technologies related to HA (High-Availability) have been provided. Meanwhile, recently, a lot of information service implementations using containers are in progress. Therefore, it should be possible to implement HA in information service using containers. Docker, the most representative container platform, provides HA-related functions. In this study, we check how to implement HA using Docker and check the necessary settings. And based on the confirmed settings, the HA service using the container is implemented.

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The Research on The Stability as Fill Material of Soil Defiled by Oil Element and Heavy Metals (중금속 및 유류로 오염된 토질의 성토재료로서의 안정성에 관한 연구)

  • Lee, Chung-Sook;Eom, Tae-Kyu;Choi, Yong-Kyu;Lee, Min-Hee
    • Journal of the Korean GEO-environmental Society
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    • v.5 no.2
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    • pp.5-13
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    • 2004
  • In the site for apartment construction, the contaminated soils of the heavy metal and the oil were appeared. The representative soil samples were sampled at 7 sampling points. To confirm the geotechnical stability of the contaminated soils, the environmental checks for the heavy metal and the oil. The soils of 2 sampling points were contaminated heavily, so it was estimated that these soils must be disused. For 1 sampling point of the slightly contaminated soil, to confirm the re-applicability of fill material, the stability analysis was performed and it was concluded that this soil will be able to re-use.

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The suture bridge transosseous equivalent technique for Bony Bankart lesion

  • Choe, Chang-Hyeok;Kim, Sin-Geun;Baek, Seung-Hun;Sin, Dong-Yeong
    • The Academic Congress of Korean Shoulder and Elbow Society
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    • 2008.03a
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    • pp.178-178
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    • 2008
  • In order to improve static stability and healing of reattached labrum, we combined the advantages of suture bridge and transosseous technique. Using the conventional 3 portal for anterior instability, check stability of bony Bankart and preparation of glenoid bed in 3 way including removal, reshaping or mobilization of bony fragment. Two anchors were inserted to the superior and inferior portion and medial edge of bony Bankart lesion. It usually corresponded to the area of IGHL. Medial mattress sutures were applied around IGHL complex to get enough depth of glenoid coverage using suture hook. Make 3.5mm pushlock anchor hole to the articular edge of glenoid cartilage. Proximal suture bridge was applied at first and then distal suture bridge was inserted to mobilize the labrum in proximal direction. These construction can provide more stable labral repair with wide contact and compression in case of deficient bony stability. It not only avoids technical disadvantage of point contact with anchor fixation, but also decreasing gap formation through cross compression of labrum that couldn't gain even with the transosseous fixation which affords linear compression effect. Additional bony stability could be gained if the the bony fragment was mobilized to the glenoid margin with potential healing bed or reshaped for the good contact with reattached labrum.

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