• Title/Summary/Keyword: Testing Environments

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A Study on Distributed System Construction and Numerical Calculation Using Raspberry Pi

  • Ko, Young-ho;Heo, Gyu-Seong;Lee, Sang-Hyun
    • International journal of advanced smart convergence
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    • v.8 no.4
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    • pp.194-199
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    • 2019
  • As the performance of the system increases, more parallelized data is being processed than single processing of data. Today's cpu structure has been developed to leverage multicore, and hence data processing methods are being developed to enable parallel processing. In recent years desktop cpu has increased multicore, data is growing exponentially, and there is also a growing need for data processing as artificial intelligence develops. This neural network of artificial intelligence consists of a matrix, making it advantageous for parallel processing. This paper aims to speed up the processing of the system by using raspberrypi to implement the cluster building and parallel processing system against the backdrop of the foregoing discussion. Raspberrypi is a credit card-sized single computer made by the raspberrypi Foundation in England, developed for education in schools and developing countries. It is cheap and easy to get the information you need because many people use it. Distributed processing systems should be supported by programs that connected multiple computers in parallel and operate on a built-in system. RaspberryPi is connected to switchhub, each connected raspberrypi communicates using the internal network, and internally implements parallel processing using the Message Passing Interface (MPI). Parallel processing programs can be programmed in python and can also use C or Fortran. The system was tested for parallel processing as a result of multiplying the two-dimensional arrangement of 10000 size by 0.1. Tests have shown a reduction in computational time and that parallelism can be reduced to the maximum number of cores in the system. The systems in this paper are manufactured on a Linux-based single computer and are thought to require testing on systems in different environments.

Numerical Study on Designing Truncated Mooring Lines for FPSO Stability Analysis (FPSO 안정성 평가를 위한 절단계류선 모델링 수치 연구)

  • Kim, Yun-Ho;Cho, Seok-Kyu;Sung, Hong-Gun;Seo, Jang-Hoon;Suh, Yong-Suk
    • Journal of Ocean Engineering and Technology
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    • v.28 no.5
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    • pp.387-395
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    • 2014
  • In this paper, a numerical analysis for an internal turret moored vessel located at a 400-m water depth is conducted. The target vessel has an internal turret that is located at the 0.2 Lpp position from the fore-side, with $3{\times}4$ complex mooring lines installed around the turret circumference. To investigate the motion response of the vessel and the structural reliability of the lines, model tests were conducted. The KRISO ocean basin has a water depth of 3.2 m, which represents 192m using a scaling of 1:60. In order to precisely represent the real-scale condition, equivalent mooring lines needed to be designed. Truncated mooring lines were designed to supplement the restriction of the flume's water depth and increase the reliability of the model testing. These truncated mooring lines were composed of two different chains in order to match the pre-tension, simultaneously restoring the curve and variation in the effective line tension. The static similarities were compared using a static pull-out test and free decaying test, and the dynamic similarities were matched via a regular wave test and combined environments test. Consequently, the designed truncated mooring system could represent the prototype mooring system relatively well in the aspects of kinematics and dynamics.

Cryogenic Mechanical Characteristics of Laminated Plywood for LNG Carrier Insulation System (LNG운반선 방열시스템에 적용되는 적층형 플라이우드의 극저온 기계적 특성 분석)

  • Kim, Jeong-Hyeon;Park, Doo-Hwan;Choi, Sung-Woong;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.31 no.3
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    • pp.241-247
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    • 2017
  • Plywood, which is created by bonding an odd number of thin veneers perpendicular to the grain orientation of an adjacent layer, was developed to supplement the weak points such as contraction and expansion of conventional wood materials. With structural merits such as strength, durability, and good absorption against impact loads, plywood has been adopted as a structural material in the insulation system of a membrane type liquefied natural gas (LNG) carrier. In the present study, as an attempt to resolve recent failure problems with plywood in an LNG insulation system, conventional PF (phenolic-formaldehyde) resin plywood and its alternative MUF (melamine-urea-formaldehyde) resin bonded plywood were investigated by performing material bending tests at ambient ($20^{\circ}C$) and cryogenic ($-163^{\circ}C$) temperatures to understand the resin and grain effects on the mechanical behavior of the plywood. In addition, the failure characteristics of the plywood were investigated with regard to the grain orientation and testing temperature.

Design and Implegmentation of an Enterprise Server for Component-based Geographic Information Systems (컴포넌트 기반 지리 정보 시스템을 위한 엔터프라이즈 서버의 설계 및 구현)

  • Lee, Kang-Jun;Hong, Dong-Suk;Park, Ji-Woong;Han, Ki-Joon
    • Journal of Korea Spatial Information System Society
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    • v.1 no.2 s.2
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    • pp.5-20
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    • 1999
  • Recently, the new software paradigm in information technology (IT) is the component-based development (CBD) technology that has brought as a result of the distributed computing environment (DCE). The CBD has reduced a program developing time and has been designed to make a distributed computing environment easier in the Internet and Intranet environments. These changes of software technology have influence on the geographic information system (GIS) and the CBD technology is highly needed as a point of view of the technique and policy of the geographic information system. In this paper, we designed and implemented an Enterprise Server for the efficient development and management of GIS components. Especially, the Enterprise Server was developed with the Enterprise JavaBeans Specification 1.1 that had been proposed as an industry standard by the Sun Microsystems. The Enterprise Server can allows users to manage the Unified Modeling Language (UML) and Design Patterns for the development of GIS components, develop a GIS component container which obeyed the Open Geodata Interoperability Specification (OpenGlS), manage spatial metadata through a spatial XML (eXtensible Markup Language) engine, and implement a TESTBED server for testing and verification of developed GIS components.

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Vibrational Characteristics of the Deteriorated Railway Plate Girder Bridge by Full-scale Experimental Modal Analysis (Full-scale 실험 모드해석을 이용한 노후화된 철도판형교의 진동특성)

  • Kim, Joo-Woo;Jung, Hie-Young
    • Journal of Korean Society of Steel Construction
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    • v.24 no.1
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    • pp.119-128
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    • 2012
  • In this study, experimental vibration tests are performed on a real full-scale railway steel plate girder bridge, which resides in open-space environments. Using experimental modal analysis techniques, the modal parameters of the railway steel plate girder bridge yielded by the modal testing of the impact hammer are compared and investigated with the natural frequencies and mode shapes obtained by finite element analysis. This work focuses on the application of model updating techniques to measured experimental data and output-only data from an analytical vibration study that takes into account various geometric and material properties of the bridge members. A finite element model of the railway bridge structure is used to verify the modal experimental results. It is subsequently updated using the corresponding modal identification technique. The basic database is provided to evaluate damage, which can be determined based on the changes in the element properties, resulting from the process of updating the finite element model benchmark and experimental data.

Mechanical Characteristics of Kaolin-cement Mixture (카올린-시멘트 혼합재료의 공학적 특성)

  • Lee, Kyu-Hwan;Lee, Song;Yi, Chang-Tok
    • Journal of the Korean Geotechnical Society
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    • v.18 no.1
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    • pp.113-125
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    • 2002
  • Ground improvement technique of cement stabilization via Deep Soil Mixing with dry cement is gaining popularity, particularly in Japan and other parts of Southeast Asia and in Scandinavia. Cement can be mixed with deep soft clay deposits, typical of marine environments, to improve the bearing capacity and/or reduce the compressibility of the material so that an otherwise poor site can be developed. However, the strength/deformation behaviour and resulting soil structure of the clay-cement mixture is presently not well understood with respect to both dry and wet mix methods. An extensive laboratory test was carried out to determine the mechanical characteristics of kaolin-cement, with some brief examination of the effects of curing environment. Laboratory tests include triaxial tests, unconfined compression tests, isotropic consolidation testis and oedometer tests. Cement contents up to 10 percent were considered and water curing was employed. Samples were cured for 7 to 112 days while submerged in distilled water. Conventional laboratory tests were also performed. In this paper, the laboratory testing program is described and various sample preparation techniques are discussed. Preliminary triaxial compression test results and trends at varying moisture contents, cement contents, confining pressures and curing times will be presented.

Indoor and Outdoor Reception Performance Evaluation of Digital Radio Techniques in Field Trials (디지털라디오 방송의 실내외 수신 환경을 고려한 필드 테스트 성능 평가)

  • Kim, Joo-Seok;Baek, Myung-Sun;Lee, Yong-Hoon;Lee, Yong-Tae;Kim, Kyung-Seok
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.1
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    • pp.1-11
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    • 2018
  • This paper provides field test results to confirm and compare the receiving characteristics of digital radio in various environments. HD Radio and DRM+ was used for the in-band method, while DAB/DAB+/T-DMB were used for the out-of-band method. To run field tests for digital radio, a transceiver test bed was constructed in a region in Korea selected as suitable for the testing, and indoor and outdoor reception tests were conducted by selecting 16 test points with different levels of multipath. Not only was the receivability tested at the test point, but ATT margin was also applied, in order to derive the minimum reception level. Through various analyses, the findings obtained through the field tests can aid in the setting of a standard for determining the method of digital radio transmission to ensure a smooth reception environment for consumers.

Automatic C Source Code Generation Technique for DirectShow Programming (DirectShow 프로그래밍을 위한 C 소스 코드 자동 생성 기법)

  • 동지연;박선화;엄성용
    • Journal of KIISE:Computing Practices and Letters
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    • v.10 no.1
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    • pp.114-124
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    • 2004
  • In this paper, we present an automatic C source code generation system for DirectShow based multimedia application programming. In this system, C source code is automatically synthesized from the filter connection graph edited with GraphEdit, a utility tool provided with DirectShow SDK package from Microsoft. In traditional DirectShow programming environments, program design and brief testing steps are usually done with GraphEdit tool just by inserting filters and connecting them properly, while actual implementation of the program should be done separately. The filter connection graph information from GraphEdit is used just as a reference in such the implementation step. Therefore, our system which automatically generates C source code directly from the filter connection graph of GraphEdit seems very useful and many programmers can develop DirectShow based multimedia application programs more effectively and quickly using our system. In addition, our system supports more various media stream control functions for the generated application programs than the existing system such as Wizard which supports limited and fixed number of media control functions only. This feature allows more flexibility in the user interface of the generated source program and makes our system more practical for DirectShow based programming.

Hygrothermal Effect on the Strength of Carbon/Epoxy Composite Single-Lap Bonded Joints (고온습도 및 저온 환경이 복합재 접착 체결부 강도에 미치는 영향 연구)

  • Song, Min-Gyu;Kweon, Jin-Hwe;Choi, Jin-Ho;Kim, Hyo-Jin;Song, Min-Hwan;Shin, Sang-Joon;Byun, Jai-Hyun
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.38 no.2
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    • pp.119-128
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    • 2010
  • The hygrothermal effect on the strength of composite single-lap bonded joints were investigated. The specimens were manufactured in four different manufacturing methods and tested in three different environmental conditions. An interesting result is that the strengths of the joints in the elevated temperature and wet (ETW) conditions were found to be 11 ~ 23% higher than those in the room temperature and dry (RTD) environment. In contrast, the strengths of the joints in the cold temperature and dry (CTD) condition decrease by 8 ~ 21% compared to those in the RTD environment except for cobonded joint. The difference in the strength by testing environments is mainly attributed to the change of the material properties of adhesive by temperature and moisture.

An Efficient Method for Real-Time Broken Lane Tracking Using PHT and Least-Square Method (PHT와 최소자승법을 이용한 효율적인 실시간 점선차선 추적)

  • Xu, Sudan;Lee, Chang-Woo
    • Journal of KIISE:Computing Practices and Letters
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    • v.14 no.6
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    • pp.619-623
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    • 2008
  • A lane detection system is one of the major components of intelligent vehicle systems. Difficulties in lane detection mainly come from not only various weather conditions but also a variety of special environment. This paper describes a simple and stable method for the broken lane tracking in various environments. Probabilistic Hough Transform (PHT) and the Least-square method (LSM) are used to track and correct the lane orientation. For the efficiency of the proposed method, two regions of interest (ROIs) are placed in the lower part of each image, where lane marking areas usually appear with less intervention in our system view. By testing in both a set of static images and video sequences, the experiments showed that the proposed approach yielded robust and reliable results.