• Title/Summary/Keyword: Open-structure

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Analysis of Wind Pressure Coefficient for Spatial Structure Roofs by Wind Load Standards and Wind Tunnel Tests (국가별 풍하중 기준과 풍동실험에 따른 대공간 구조물 지붕의 풍압계수 분석)

  • Cheon, Dong-jin;Yoon, Sung-Won
    • Journal of Korean Association for Spatial Structures
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    • v.17 no.4
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    • pp.103-113
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    • 2017
  • Spatial Structure has suffered from a lot of damage due to the use of lightweight roofs. Among them, the damage caused by strong winds was the greatest, and the failure of the calculation of the wind load was the most frequent cause. It provides that wind tunnel test is used to calculate the wind load. However, it is often the case that the wind load is calculated based on the standard of wind load in the development design stage. Therefore based on this, the structure type and structural system and member design are often determined. Spatial structure is usually open at a certain area. The retractable roof structure should be operated with the open roof in some cases, so the wind load for the open shape should be considered, but it is not clear on the basis of the wind load standard. In this paper, the design wind pressure of a closed and retractable roof structure is calculated by KBC2016, AIJ2004, ASCE7-10, EN2005, and the applicability of wind pressure coefficient is compared with wind tunnel test.

A Design of Programmable Fragment Shader with Reduction of Memory Transfer Time (메모리 전송 효율을 개선한 programmable Fragment 쉐이더 설계)

  • Park, Tae-Ryoung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.12
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    • pp.2675-2680
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    • 2010
  • Computation steps for 3D graphic processing consist of two stages - fixed operation stage and programming required stage. Using this characteristic of 3D pipeline, a hybrid structure between graphics hardware designed by fixed structure and programmable hardware based on instructions, can handle graphic processing more efficiently. In this paper, fragment Shader is designed under this hybrid structure. It also supports OpenGL ES 2.0. Interior interface is optimized to reduce the delay of entire pipeline, which may be occurred by data I/O between the fixed hardware and the Shader. Interior register group of the Shader is designed by an interleaved structure to improve the register space and processing speed.

Research on Low Phase Noise Oscillator Using Microstrip Square Open Loop Resonator (Microstrip Square Open Loop Resonator를 이용한 저위상 잡음 발진기에 관한 연구)

  • Park Eun-Young;Seo Chulhun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.1 s.104
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    • pp.17-23
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    • 2006
  • This paper has presented a low phase noise oscillator using a square open loop with microstrip structure. A square open loop resonator has a large coupling coefficient value, which makes a high Q value, and has reduced phase noise. This oscillator has presented the oscillation frequency of 5.84 GHz, harmonics of -15.83 dBc and the phase noise of -111.17 dBc/Hz at the offset frequency of 100 kHz. In conclusion, the proposal structure has improved phase noise of 15 dB at the offset frequency of 100 kHz compared with the conventional structure of oscillator.

PERIODIC SURFACE HOMEOMORPHISMS AND CONTACT STRUCTURES

  • Dheeraj Kulkarni;Kashyap Rajeevsarathy;Kuldeep Saha
    • Journal of the Korean Mathematical Society
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    • v.61 no.1
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    • pp.1-28
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    • 2024
  • In this article, we associate a contact structure to the conjugacy class of a periodic surface homeomorphism, encoded by a combinatorial tuple of integers called a marked data set. In particular, we prove that infinite families of these data sets give rise to Stein fillable contact structures with associated monodromies that do not factor into products to positive Dehn twists. In addition to the above, we give explicit constructions of symplectic fillings for rational open books analogous to Mori's construction for honest open books. We also prove a sufficient condition for the Stein fillability of rational open books analogous to the positivity of monodromy for honest open books due to Giroux and Loi-Piergallini.

Control Method to Single Degree or Three Degrees of Freedom for Hybrid Testing (하이브리드 실험을 위한 1 또는 3자유도에 대한 제어 기법)

  • Lee, Jae-Jin;Kang, Dae-Hung;Kim, Sung-Il
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2409-2421
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    • 2011
  • This paper will present hybrid tests to a one bay-one story steel frame structure under ground excitation. A structure used in this paper for hybrid test, to evaluate performance and behavior, is divided into two models; one is numerical model with one column element, and a truss or a beam element, the other is physical substructural model with one beam-column element. All tests considered one or three degrees of freedom to implement real-time hybrid test, and two control algorithms to control hardware are used; one using MATLAB/Simulink, the other using OpenSees, OpenFresco and xPCTarget. In addition, for real-time data communication between numerical and physical substructural models SCRAMNet was used. The results of hybrid tests were compared with one of numerical analysis of numerical model with fiber force-based beam-column elements using OpenSees. Real-time hybrid tests were implemented for the validation of control system with simple structure, and then it will be extended to hybrid test for higher nonlinear or complex structure later on.

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A Study on the Intellectual Structure of Domestic Open Access Area (국내 오픈액세스 분야의 지적구조 분석에 관한 연구)

  • Shin, Jueun;Kim, Seonghee
    • Journal of the Korean Society for Library and Information Science
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    • v.55 no.2
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    • pp.147-178
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    • 2021
  • In this study, co-word analysis was conducted to investigate the intellectual structure of the domestic open access area. Through KCI and RISS, 124 research articles related to open access in Korea were selected for analysis, and a total of 1,157 keywords were extracted from the title and abstract. Network analysis was performed on the selected keywords. As a result, 3 domains and 20 clusters were extracted, and intellectual relations among keywords from open access area were visualized through PFnet. The centrality analysis of weighted networks was used to identify the core keywords in this area. Finally, 5 clusters from cluster analysis were displayed on a multidimensional scaling map, and the intellectual structure was proposed based on the correlation between keywords. The results of this study can visually identify and can be used as basic data for predicting the future direction of open access research in Korea.

The Analysis and Application of the Parallel Coupled Line with Open Stub (개방 스터브를 갖는 평행결합선로의 해석과 응용)

  • Lee, Won-Kyun;Lee, Hong-Seob;Hwang, Hee-Yong
    • Journal of Industrial Technology
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    • v.27 no.B
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    • pp.153-160
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    • 2007
  • In this paper, the exact analysis of the parallel coupled line with open stub is presented. This structure shows LPF characteristics with broad stopband and sharp skirt characteristics. We derived the exact Z-matrix expression of the structure. In order to show the validation of the expression we designed $3^{th}$ order Chebyshev LPF using the structure. The simulated data excellently agreed with the predicted values by the calculation using the derived expression.

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A Study on Architectural Acoustic Characteristics of an Open Air Performance Hall with the Membrane Structure (테프론(TEFRON)막 구조 야외공연장의 건축음향특성 분석에 관한 연구)

  • Kim, Jung-Joong;Sohn, Jang-Yeul;Park, Hye-Na
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.11a
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    • pp.649-653
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    • 2005
  • Recently, many membrane structure buildings are constructed with the trend of multi functional and high technological construction. The membrane structure has the characteristics such as distinguished architectural shape which can make variable space creation and can make economic use of material. Therefore, it is in the spotlight of sport complex, various concert hall, and public service buildings. However, the acoustic study of membrane structure has not been following up the increasing demand for the membrane structure. In this study, the acoustic characteristics of membrane structure will be studied and analyzed using architectural acoustic factors based on acoustic design theory And also, the differences between theoretical exhortation value and outcome of study will be studied with the basis of architectural acoustic material study.

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Design of OpenScenario Structure for Content Creation Service Based on User Defined Story (사용자 정의 스토리 기반 콘텐츠 제작 서비스를 위한 오픈 시나리오 언어 구조 설계)

  • Lee, Hyejoo;Kwon, Ki-Ryong;Lee, Suk-Hwan;Park, Yun-Kyong;Moon, Kyong Deok
    • Journal of Korea Multimedia Society
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    • v.19 no.2
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    • pp.170-179
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    • 2016
  • It is a story-based content creation service that provides any user with some proper contents based on a story written by the user in order to utilize a lot of contents accumulated on Internet. For this service, the story has to be described in computer-readable representation. In this paper, analyzing the structure of scenario, as known as screenplay or scripts, a structure of story representation, which is referred to as OpenScenario, is defined. We intend users to produce their own contents by using massive contents on Internet by the proposed method. The proposed method's OpenScenario consists two main parts, OSD (OpenScenario Descriptors) which is a set of descriptors to describe various objects of shots such as visual, aural and textual objects and OSS (OpenScenario Scripts) which is a set of scripts to add some effects such as image, caption, transition between shots, and background music. As an usecase of proposed method, we describe how to create new content using OpenScenario and discuss some required technologies to apply the proposed method effectively.

Performance Improvement of Very Low Head Cross Flow Turbine with Inlet Open Duct (입구 개방형 덕트를 적용한 초저낙차 횡류수차의 성능향상)

  • Chen, Zhenmu;Singh, Patrick Mark;Choi, Young-Do
    • The KSFM Journal of Fluid Machinery
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    • v.17 no.4
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    • pp.30-39
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    • 2014
  • The cross flow turbine is economical because of its simple structure. For remote rural region, there are needs for a more simple structure and very low head cross flow turbines. However, in this kind of locations, the water from upstream always flows into the turbine with some other materials such as sand and pebble. These materials will be damage to the runner blade and shorten the turbine lifespan. Therefore, there is a need to develop a new type of cross flow turbine for the remote rural region where there is availability of abundant resources. The new design of the cross flow turbine has an inlet open duct, without guide vane and nozzle to simplify the structure. However, the turbine with inlet open duct and very low head shows relatively low efficiency. Therefore, the purpose of this study is to optimize the shape of the turbine inlet to improve the efficiency, and investigate the internal flow of a very low head cross flow turbine. There are two steps to optimize the turbine inlet shape. Firstly, by changing the turbine open angle along with changing the turbine inlet open duct bottom line (IODBL) location to investigate the internal flow. Secondly, keeping the turbine IODBL location at the maximum efficiency achieved at the first step, and changing the turbine IODBL angle to improve the performance. The result shows that there is a 7.4% of efficiency improvement by optimizing turbine IODBL location (open angle), and there is 0.3% of efficiency improvement by optimizing the turbine IODBL angle.