• Structural Engineering and Mechanics
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• 제10권1호
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• pp.17-26
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• 2000

This paper presents a case study with a multi-degree-of-freedom (MDOF) system where the Floor Response Spectra (FRS) have been derived from a large ensemble of ground motion accelerograms. The FRS are evaluated by the frequency response function which is calculated numerically. The advantage of this scheme over a repetitive time-history analysis of the entire structure for each accelerogram of the set has been highlighted. The present procedure permits generation of FRS with a specified probability of exceedence.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 가을 학술발표회 논문집
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• pp.447-454
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• 1998

The paper describes the second half of the research for the development of Neural-Networks-based model for the generation of an Artificial earthquake and a Response Spectrum(NNARS). Based on the redefined traditional processes related to the generation of an earthquake acceleration response spectrum and design spectrum, four neural-networks-based models are proposed to substitute the traditional processes. RS_NN tries to directly generate acceleration response spectrum with basic data that are magnitude, epicentral distance, site conditions and focal depth. The test results of RS_NN are not good because of the characteristics of white noise, which is randomly generated. ARS_NN solve this problem by the introduction of the average concept. IARS_NN has a role to inverse the ARS_NN, so that is applied to generate a ground motion accelerogram compatible with the shape of a response spectrum. Additionally, DS_NN directly produces design spectrum with basic data. As these four neural networks are simulated as a step by step, the paper describes the methods to generate a response spectrum and a design spectrum using the neural networks.

• Asian-Australasian Journal of Animal Sciences
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• 제14권7호
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• pp.899-904
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• 2001

A field trial on selection for increased live weight in Black Bengal (BB) goat was conducted over two generations. Parents of both sexes were selected (mass selection) based on mature body weight criteria set against age. A parallel randomly mated line was maintained to compare the response (R) of selection at birth. 3, 6, 9 and 12 months of age in both generations. Lactation yield (LY), average per day yield (APDY) and lactation length (LL) were evaluated in the selected line in comparison to randombreds as a result of correlated response. Live weights were significantly improved at onward bir:th in first generation and only at birth in second generation. Improvements (%) in live weight at 3, 6. 9 and 12 months in first generation were 17.6, 18.4, 16.6, and 12.0 at birth in second generation. Significant correlated R were found in LY and APDY. Results suggest that there may be a positive relationship between live weight and lactational traits in BB goats of Bangladesh. It was also concluded that such a field scheme can be effectively used for genetic improvement of goats in subsistence farming, at least for short term gain.

• 한국해양공학회지
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• 제34권6호
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• pp.454-460
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• 2020

In 2019, the Korean government announced the 3rd Basic Plan for Energy, which included expanding the rate of renewable energy generation by 30-40% by 2040. Hence, offshore wind power generation, which is relatively easy to construct in large areas, should be considered. The East Sea coast of Korea is a sea area where the depth reaches 50 m, which is deeper than the west coast, even though it is only 2.5 km away from the coastline. Therefore, for offshore wind power projects on the East Sea coast, a floating offshore wind power should be considered instead of a fixed one. In this study, a response analysis was performed by applying the analytical conditions of IEC61400-3-2 for the design of floating offshore wind power generation systems. In the newly revised IEC61400-3-2 international standard, design load cases to be considered in floating offshore wind power systems are specified. The upper structure applied to the numerical analysis was a 5-MW-class wind generator developed by the National Renewable Energy Laboratory (NREL), and the marine environment conditions required for the analysis were based on the Ulsan Meteorological Buoy data from the Korea Meteorological Administration. The FAST v8 developed by NREL was used in the coupled analysis. From the simulation, the maximum response of the six degrees-of-freedom motion and the maximum load response of the joint part were compared. Additionally, redundancy was verified under abnormal conditions. The results indicate that the platform has a maximum displacement radius of approximately 40 m under an extreme sea state, and when one mooring line is broken, this distance increased to approximately 565 m. In conclusion, redundancy should be verified to determine the design of floating offshore wind farms or the arrangement of mooring systems.

• 한국수정란이식학회지
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• 제20권3호
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• pp.217-232
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• 2005

The objective of this study was to determine the response of QTL in each generation during selection to develop inbred lines. The simulation program was written in Fortran. Magnitude of QTL effects, base population size, number of QTL assigned to population, and the allelic frequency for the positive allele at each major QTL were highly associated with number of generations to fixation of QTLs during selection. Populations with larger QTL effects and larger base population size had more individuals with fixed QTL. However, a smaller number of QTL assigned to population had a higher fraction of individuals with fixed QTL at each generation compared with more populations with QTL. This simulation study will help to design biological experiments for detection of QTL-marker association using inbred population and to determine optimum number of lines with fixed QTL during inbred line development. To complement this study, additional simulation should be need with abundant replicates, more various population sizes, magnitude of QTL effects, and recombination between markers and QTLs.

• 전기학회논문지
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• 제66권1호
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• pp.23-26
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• 2017

Social Welfare is useful concept for evaluating the effectiveness of an economic policy in micro economics. This paper focuses on Social Welfare(SW) of electricity market incorporating demand response(DR). Competition between DR and generation company is modeled as a simple bid function. DR function can be considered as an negative generation(called Negawatt) and as an element of modified demand function. These two approaches result in the same demand reduction, generation power, and the market price. However, SW in the modified demand function approach is not identical to SW in the Negawatt approach. It makes the numerical index of DR effectiveness less persuasive. This paper proposes modified definition of SW in the demand function approach. The proposed definition of SW leads the DR effectiveness index to be identical to that in the Negawatt approach.

• 가족자원경영과 정책
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• 제25권4호
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• pp.71-86
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• 2021

본 연구는 기혼 남성의 가사노동참여 양상의 변화를 파악하기 위해 남성의 가사노동시간의 영향 요인을 세대별로 파악하는 목적으로 한다. 이를 위해 기혼남성을 베이비붐세대, X세대, Y세대로 구분하고, 각 세대별 가사노동참여 요인을 가사노동 참여가설을 적용시켜 분석해 보았다. 자료는 통계청 '2019년 생활시간조사' 원자료를 사용하였다. 기혼남성의 가사노동시간에 영향을 미치는 요인을 분석하기 위해 다항로지스틱 분석을 실시하였다. 분석결과 베이비붐세대 기혼남성의 가사노동시간은 경제적 효율성가설과 성역할태도가설, 요구반응가능성가설에 의해 설명이 가능하고, X세대 기혼남성의 가사노동시간은 경제적 효율성가설, 성역할태도가설, 시간가용성가설, 요구반응가능성가설 모두에 의해 설명이 가능하였다. 반면, Y세대 기혼남성의 가사노동시간은 시간가용성가설과 요구반응가능성가설에 의해서만 설명이 가능하였다. 세대별로 가사노동참여의 동인이 다르다는 사실은 남성 대상 일가정양립지원 정책수립에 있어 세대별 특성을 고려해야 한다는 점을 시사해준다.

• Steel and Composite Structures
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• 제10권5호
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• pp.429-455
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• 2010

The current research presents a detailed methodology for generating air blast loading for use within a finite element context. Parameters describing blast overpressure loading on a structure are drawn from open literature sources and incorporated within a blast load generation computer code developed for this research. This open literature approach lends transparency to the details of the blast load modeling, as compared with many commonly used approaches to blast load generation, for which the details are not publicly available. As a demonstration, the load generation code is used with the finite element software LS-DYNA to simulate the response of a steel plate and girder subjected to explosions modeled using these parameters as well as blast parameters from other sources.

• 비파괴검사학회지
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• 제36권2호
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• pp.149-154
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• 2016

The use of nonlinear ultrasonics wave has been accepted as a promising tool for monitoring material states related to microstructural changes, as it has improved sensitivity compared to conventional non-destructive testing approaches. In this paper, third harmonic generation of shear horizontal guided waves propagating in an isotropic plate is investigated using the perturbation method and modal analysis approach. An experimental procedure is proposed to detect the third harmonics of shear horizontal guided waves by electromagnetic transducers. The strongly nonlinear response of shear horizontal guided waves is measured. The accumulative growth of relative acoustic nonlinear response with an increase of propagation distance is detected in this investigation. The experimental results agree with the theoretical prediction, and thus providing another indication of the feasibility of using higher harmonic generation of electromagnetic shear horizontal guided waves for material characterization.

• Journal of Electrical Engineering and Technology
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• 제12권5호
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• pp.1719-1728
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• 2017

Recent concerns about environmental conditions have triggered the growing interest in using green energy resources. These sources of energy, however, bring new challenges mainly due to their uncertainty and intermittency. In order to alleviate the concerns on the penetration of intermittent energy resources, this paper investigates impacts of realizing demand-side potentials. Among different demand-side management programs, this paper considers demand response wherein consumers change their consumption pattern in response to changing prices. The research studies demand response potentials from different load sectors on generation system well-being. Consumers' sensitivity to time-varying prices is captured via self and cross elasticity coefficients. In the calculation of well-being indices, sequential Monte Carlo simulation approach is accompanied with fuzzy logic. Finally, IEEE-RTS is used as the test bed to conduct several simulations and the associated results are thoroughly discussed.