• 전자공학회논문지
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• 제51권4호
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• pp.27-32
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• 2014

단위행렬의 각 행을 공간부호로 사용하고 symmetric balance incomplete block design(BIBD) 부호를 스펙트럼부호로 사용한 2차원(2-D) 하이브리드 부호를 제안한다. 단위행렬의 각 행을 공간부호로 사용함으로써 수신기의 구조가 간단해지고 송수신단을 연결하는 방법도 간단해 짐을 알 수 있었다. 또한 비이상적 BIBD 부호를 스펙트럼부호로 사용하여 입력신호가 작을때도 효율적으로 동작할 수 있었다. 사용자 수에 따른 비트 오차율(BER) 분석을 통하여 제안하는 2-D 하이브리드 부호가 1차원(1-D) BIBD 부호에 비하여 최대사용자 수를 현저하게 증가시킬 수 있음을 알 수 있었다.

• 한국공간구조학회논문집
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• 제20권1호
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• pp.41-48
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• 2020

In this study, the design of anchorage zone for unbonded post-tensioned concrete beam with single tendons of ultimate strength 2400MPa was evaluated to verify that the KDS 14 20 60(2016) and KHBDC 2010 codes are applicable. The experimental results showed that the bursting force equation of current design codes underestimated bursting stress measured by test, because the KDS 14 20 60(2016) and KHBDC 2010 propose the location of the maximum bursting force 0.5h which is the half of the height of member regardless of stress contribution. Although the allowable bearing force calculated by current design codes was not satisfied the prestressing force, the cracks and failure in anchorage zone was not observed due to the strengthening effect of anchorage zone reinforcement.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.1001-1008
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• 2006

The main objective of this paper is to compare economical effectiveness of typical methods for checking stability in principal components of steel cable-stayed bridges. Elastic and inelastic buckling analyses are carried out for frame-like numerical models of cable-stayed bridges. The axial-flexural interaction equations prescribed in AASHTO Allowable Stress Design (ASD) and AASHTO Load and Resistance Factor Design (LRFD) are used in order to check the stability of principal components. Parametric studies are performed for numerical models which have the center span length of 300m, 600m, 900m and l200m with different girder depths. Peak values of the interaction equations are calculated at the intersection point between girders and towers. These peak values are considered as a major factor to design of principal components of cable-stayed bridges. As a result, more economical design for girders and towers can be feasible using the inelastic buckling analysis. In addition, LRFD codes are more economical about 20% on the average than ASD codes for all numerical models of cable-stayed bridges.

• Wind and Structures
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• 제22권2호
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• pp.133-160
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• 2016

Hurricanes are among the most costly natural hazards to impact buildings in coastal regions. Building roofs are designed using the wind load provisions of building codes and standards and, in the case of large buildings, wind tunnel tests. Wind permeable roof claddings like roof pavers are not well dealt with in many existing building codes and standards. The objective of this paper is to develop simple guidance in code format for design of loose-laid roof pavers. Large-scale experiments were performed to investigate the wind loading on concrete roof pavers on the flat roof of a low-rise building in Wall of Wind, a large-scale hurricane testing facility at Florida International University. They included wind blow-off tests and pressure measurements on the top and bottom surfaces of pavers. Based on the experimental results simplified guidelines are developed for design of loose-laid roof pavers against wind uplift. The guidelines are formatted so that use can be made of the existing information in codes and standards such as American Society of Civil Engineering (ASCE) 7-10 standard's pressure coefficients for components and cladding. The effects of the pavers' edge-gap to spacer height ratio and parapet height to building height ratio are included in the guidelines as adjustment factors.

• Wind and Structures
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• 제37권2호
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• pp.133-151
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• 2023

This paper first provides a wide overview about the design codes and standards covering the use of Computational Wind Engineering / Computational Fluid Dynamics (CWE/CFD) for wind-sensitive structures and built environment. Second, the paper sets out the basic assumptions and underlying concepts of the new Annex T "Simulations by Computational Fluid Dynamics (CFD/CWE)" of the revised version "Guide for the assessment of wind actions and effects on structures" issued by the Advisory Committee on Technical Recommendations for Constructions of the Italian National Research Council in February 2019 and drafted by the members of the Special Interest Group on Computational Wind Engineering of the Italian Association for Wind Engineering (ANIV-CWE). The same group is currently advising UNI CT021/SC1 in supporting the drafting of the new Annex K - "Derivation of design parameters from wind tunnel tests and numerical simulations" of the revised Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions. Finally, the paper outlines the subjects most open to development at the technical and applicative level.

• Korean Chemical Engineering Research
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• 제58권3호
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• pp.493-497
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• 2020

Hazardous area classification is designed to prevent chemical plant explosions in advance. Generally, the duration of the explosive atmosphere is used for zone type classification. Herein, IEC code, a quantitative zone type classification methodology, was used to achieve Zone 2 NE, which indicates a practical non-explosion condition. This study analyzed the operating pressure of a vessel handling propane to achieve Zone 2 NE by applying the IEC code via MATLAB. The resulting zone type and hazardous area grades were compared with the results from other design standards, namely API and EI codes. According to the IEC code, the operating pressure of vessels handling propane should be between 101325-116560.59 Pa. In contrast, the zone type classification criteria used by API and EI codes are abstract. Therefore, since these codes could interpret excessively explosive atmospheres, care is required while using them for hazardous area classification design.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.429-436
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• 2005

This paper reflects on the ergonomical criteria for a humane working atmosphere in industrial buildings while respecting and paying close attention to the physical, mental, and stressful demands of the work environment. It describes effective construction codes and standards of practice and their importance in ensuring a safe environment for working people. Also addressed are the objectives for a productive work environment and its organization. The paper considers the significance of a proper working environment, the use of dangerous working materials, the use of proper ventilation, climate, and lighting to ensure that the productivity of the enterprise is met with common goals shared between employer and employee. The connection between the legal foundation and the design of industrial construction is the focus of this paper. It shows that the planning and executive persons are obliged to observe the relevant construction laws and regulations including standards and codes of practice. Additionally discussed are the possible solutions and consequences for development in the productional, constructional, and ergonomical fields of design.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.42-46
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• 2005

In spite of fast growing of prediction codes, there is still not negligible uncertainty in their results. This uncertainty affects on the turbine structural design and power production prediction. With the growing size of wind turbine, reducing this uncertainty is becoming one of critical issues for high performance and efficient wind turbine design. In this respect, there are international efforts to evaluate and tune prediction codes of wind turbine. As the reference data for this purpose, field test data is not appropriate because of its uncontrollable wind characteristics and its inherent uncertainty. Wind tunnel can provide controllable wind. For this reason, NREL has done the full scale test of the 10m turbine at NASA-Ames. With this reference data, a blind comparison has been done with participation of 18 organizations with 19 modeling tools. The results were not favorable. In Europe, a similar project is going on. Nine organizations from five countries are participating in the MEXICO project to do full scale wind tunnel tests and calculation with prediction codes. In this study. these two projects were reviewed in respect of wind tunnel test and its contribution. As a conclusion, it is suggested that scale model wind tunnel tests can be a complementary tool to calculation codes which were evaluated worse than expected.

• 한국주거학회논문집
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• 제15권6호
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• pp.107-113
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• 2004

Fire was and remains a great threat to historic buildings of wood. This threat is omnipresent and often results to irreparable property losses especially cultural heritages. Fire of historic buildings continues to increase every year. The purpose of this study is to preserve a life safety, historical heritage and architectural & cultural values by pursuing for fire safety in the historical buildings. This study shall employ two research methods: a literature review and field survey methods. The literature review shall focus on the observations of characteristics noted in fire codes. The field survey shall cover a heat analysis and fire protection equipment. A method is proposed to investigate fire codes related historical building, reported fire history Fire Codes and Regulations for modern buildings are not always applicable on the historic buildings. Old buildings, and some new buildings with architectural, historical or cultural importance may have values which cannot be measured on a monetary scale. Their protection against the damage caused by fire is considered to be one of the basic moral duties of society. It is strongly recommended, therefore, legislation for fire safety in historical buildings must be extended to a complementary relationship with 'active' fire protection measures, to provide safety in real historical building in real fire situations. The development and application of performance based Codes and the Fire Safety Engineering approach seems to be a rather reasonable and effective way to deal with this historical buildings.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1991년도 학술발표회 논문집
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• pp.151-156
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• 1991

In this paper, we propose a new algorithm for designing the R-G filter that has optimum performance in terms of mean square sidelobe level(MSSL) for the Barker code. The advantage of the conventional R-G filter lies in its simple structure so that it can be easily implemented. However, the conventional R-G filter dose not have optimum performances in terms of peak sidelobe level(PSL), mean sidelobe level(MSL), and MSSL. Recently, a(R-G)LP filter of which filter coefficients are obtained by the linear programming algorithm was proposed and known to have optimum performance in PSL. The proposed (R-G)LS filter keeps the simple structure of the conventional R-G filter and has the filter coefficients that minimizes the sidelobe in the least square sense. The analytic results show that the proposed (R-G)LS filter has better performances than the conventional R-G filter in terms of PSL, MSL, and MSSL. Compared with (R-G)LP filter, the proposed (R-G)LS filter has better performances in terms of MSL and MSSL. The proposed filter design algorithm can be applied to the other binary codes such as truncated pseudonoise(PN) codes and concatenated codes.