• Earthquakes and Structures
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• 제16권5호
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• pp.575-588
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• 2019

Seismic design method based on bearing capacity has been widely adopted in building codes around the world, however, damage and collapse state of structure under strong earthquake can not be reflected accurately. This paper aims to present a deformation-based seismic design method based on the research of RC component deformation index limit, which combines with the feature of Chinese building codes. In the proposed method, building performance is divided into five levels and components are classified into three types according to their importance. Five specific design approaches, namely, "Elastic Design", "Unyielding Design", "Limit Design", "Minimum Section Design" and "Deformation Assessment", are defined and used in different scenarios to prove whether the seismic performance objectives are attained. For the components which exhibit ductile failure, deformation of components under strong earthquake are obtained quantitatively in order to identify the damage state of the components. For the components which present brittle shear failure, their performance is guaranteed by bearing capacity. As a case study, seismic design of an extremely irregular twin-tower high rise building was carried out according to the proposed method. The results evidenced that the damage and anti-collapse ability of structure were estimated and controlled by both deformation and bearing capacity.

• Ocean Systems Engineering
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• 제10권2호
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• pp.131-161
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• 2020

The objective of this study was to evaluate the downtime cost of side-by-side offloading operations in Malaysian waters. With the help of a numerical time domain tool, the structure and cable response of moored FPSO vessel was simulated for heading and beam sea-states under irregular waves. The weather downtime was assessed by comparing the response under operational wave condition with the pre defined industrial safe offloading criteria. Additionally, two cases of cable failure were simulated for each sea-state. The novel study on downtime cost was presented for three different location of Malaysia subcontinent for which the location specific wave scatter diagram facilitated to estimate the probability of occurrence of operational wave condition. It was concluded that an unpredictable increment in wave height by 0.5 m can significantly impact the production cost.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.198-203
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• 2002

A fuzzy logic controller design technique is proposed to apply for the control of flexible system under irregular disturbance. The fuzzy rules of $\ulcorner$Mode Selecting Fuzzy Controller$\lrcorner$ are constructed using displacement, velocity information and modal characteristics of the system. The frequency information of flexible system is picked up from $\ulcorner$Mode Selecting Unit$\lrcorner$ based on Fast-Fourier transform algorithm. Experiment is conducted to verify the proposed theoretical approach, Piezo ceramic and laser accelerometer are used as actuator and sensor in the experiments respectively

• 한국정보처리학회논문지
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• 제5권7호
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• pp.1943-1950
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• 1998

본 논문에서는 평판 플라즈마 표시장치(PDP)의 휘도를 개선할 수 있는 방법으로서 불규칙 어드레싱 방식을 제안하고 있다. 종래의 계조 조정 방식에서 주사 전극의 선택이 한 가지 순열조합에 의해 순차적으로 일어나는 것에 반하여 불규칙 어드레싱에서는 화소의 발광시간을 90%이상으로 늘릴 수 있도록 비순차적으로 주사 전극을 선택한다. 이 방식은 PDP의 물리적 구조에 무관하며 구동 전압이나 전류 등을 바꾸지 않고도 구현이 가능한 장점을 가진다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문초록집
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• pp.326.1-326
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• 2002

A fuzzy logic controller design technique is proposed to apply to the control of flexible system under irregular disturbance. The fuzzy rules of $\ulcorner$Mode Selecting Fuzzy Controller$\lrcorner$ are constructed using displacement, velocity information and modal characteristics of the system. The frequency information of flexible system is picked up from $\ulcorner$Mode Selecting Unit$\lrcorner$ based on Fast-Fourier transform algorithm. Experiment is conducted to verify the proposed theoretical approach. (omitted)

• 한국농공학회논문집
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• 제48권4호
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• pp.3-12
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• 2006

Watershed is the land area that contributes runoff to an outlet point. To delineate an watershed, watershed delineation using GIS that contains grid data structure is the most general method. Some researchers have studied to implement algorithms that revise the TIN topography since it is difficult to delineate watershed boundary more accurately. In this study kruskal's greedy algorithm and triangulated irregular network (TIN) were used to delineate a watershed. This method does not require a conversion from to DEM in grid and automatically obtain(generates) the oulet points. Delineation algorithm was tested in Geosan-gun, Chung-cheongbuk-do and get small watershed areas. Finally, kruskal's algorithm could operate more precisely with revision algorithm.

• 한국공간구조학회논문집
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• 제18권1호
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• pp.85-92
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• 2018

Construction techniques and materials are developing and structures are designed to be irregular shaped, and therefore more detailed structural analysis is required. The purpose of this study is to analyze the cause of accidents related to falsework systems during construction and discuss prevention methods in order to prevent accidents relate to prefabricated shoring system during construction. In this paper structural analysis was conducted to study the influence of slab irregularity on system supports and analysis to investigate the participation of the bracing in the system support.

• Earthquakes and Structures
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• 제8권1호
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• pp.77-100
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• 2015

Multiple tuned mass dampers (MTMDs) tuned to various frequencies have been shown to efficiently control the seismic response of structures where multiple modes are dominant. One example is irregular structures that are found more vulnerable than their symmetric counterparts. With the technology of MTMDs available, design and optimal design methodologies are required for application. Such a methodology, in the form of an analysis/redesign (A/R) scheme, has been previously presented by the authors while limiting responses of interest to allowable values, i.e., performance-based design (PBD). In this paper, the A/R procedure is modified based on formal optimality criteria, making it more cost efficient, as well as more computationally efficient. It is shown that by using the methodology presented herein, a desired performance level is successfully targeted by adding near-optimal amounts of mass at various locations and tuning the TMDs to dampen several of the structure's frequencies. This is done using analysis tools only.

• Steel and Composite Structures
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• 제14권4호
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• pp.349-365
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• 2013

Structures consisting of concrete and steel parts, which are irregular in damping ratios are investigated. This investigation is a code-based seismic design of such structures. Several practical difficulties encountered, due to inherent differences in the nature of dynamic response of each part, and the different damping ratios of the two parts. These structures are irregular in damping ratios and have complex modes of vibration so that their analysis cannot be handled with the readily available commercial software. Therefore, this work aims to provide simple yet sufficiently accurate constant values of equivalent damping ratios applied to the whole structure for handling the damping irregularity of such structures. The results show that the equivalent damping ratio changes with the height of the building and the kind of the structural system, but it is constant for all accelerations values. Thus, available software SAP2000 applied for seismic analysis, design and the provisions of existing seismic codes. Finally, evaluation of different kinds of structural system used in this research to find the most energy dissipating one found by finding the best value of quality coefficient.

• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 1998년도 봄 학술발표회 논문집
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• pp.135-139
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• 1998

Poly(vinyl acetate) (PVAc) from which atactic poly(vinyl alcohol) (PVA) is derived, is always noncrystalline. This was attributed to the irregular steric arrangement of the acetyl groups in PVAc. However, the X-ray diffraction patterns of atactic PVA, a derivative of PVAc, were found to show distinct crystallinity, and to give an identity period of 2,52 ${\AA}$ along the fiber axis, despite the expectation of an irregular arrangement of the hydroxyl groups in atactic PVA, in the same manner as that of the acetyl groups in PVAc.(omitted)