• 한국지반공학회논문집
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• 제22권5호
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• pp.59-67
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• 2006

동일한 흙으로 조성된 모형지반에 대하여 1-g 모형실험과 원심모형실험을 수행하고 그 결과를 비교하였다. 원형지반은 10m 두께의 수평하고 느슨한 포화 사질토 지반으로 가정하였다. 1-g 모형실험은 1/20 축소모형, 원심모형실험은 1/40 축소모형을 이용하였다. 원심모형실험의 경우 점성유체를 사용하여 동적시간에 대한 상사비와 과잉간극수압소산시간에 대한 상사비가 동일하도록 하였다. 원심모형실험의 계측결과는 원형지반의 거동으로 가정하였다. 그리고, 1-g모형실험에 정상상태개념 및 두 가지 시간상사비 등을 적용하여 원형지반의 거동을 모사하고자 하였다. 동일한 위치에서의 과잉간극수압, 지반가속도 그리고 지표 침하량 등을 계측하여 비교하였다. 실험결과 지반의 투수계수가 작아서 진동 중 과잉간극수압 소산의 영향이 작고, 소산시간상사비를 적절하게 결정하면 1-g 모형실험으로부터 원형지반의 과잉간극수압 거동을 모사할 수 있는 것으로 나타났다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1081-1084
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• 1998

In this paper, we propose the bus coding technique for low power consumption. For CMOS circuit most power is dissipated as dynamic power for charging and discharging node capacitances.Though the I/O and bus are likely to have the very large capacitances associated with them and dissipate much of the power dissipated by an IC, they have little beenthe special target for power reduction. The conventional Bus-Invert coding method can't decrease the peak power dissipation by 50% because the additional invert signal line can invoke a transition at the time when Bus-Invert coding isn't used to code original bus data. The proposed technique always constraints the Hamming distance between data transferred sequentially to be below the half of the bus width, and thus decrease the I/O peak power dissipation and the I/O average power dissipation.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 2001년도 춘계학술대회 논문집
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• pp.371-378
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• 2001

To enhance seismic performance of a structure ATC-40 and FEMA-273 propose technical strategies such as increasing strength, altering stiffness, and reducing demand by employing base isolation and energy dissipation devices. Specifically the energy dissipation devices directly increase the ability of the structure to dampen earthquake response. However nonlinear dynamic time history analysis of a structure with energy dissipation devices is complicated and time consuming. In this study a simple and straightforward procedure is developed using effective damping ratio to obtain the required amount of viscoelastic dampers in order to meet given performance objectives. Parametric study has been performed for the period of the structure, yield strength, and the stiffness after the first yield. According to the analysis results, earthquake demand and required damping ratio were reduced by installing viscoelastic dampers. The results also show that with the addition of the supplemental damping evaluted by the proposed method the performance of the model structures are well restrained within the target point.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.113-114
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• 2022

The purpose of this study is to identify the rear energy transfer amount and time delay capability of the protection panel that has been impated by a projectile and the protection panel reinforced the foam polypropylene on the rear of the fiber reinforced cement itious composites, and compared and analyzed the load resistance capacity, energy dissipation capacity, and impact delay capacity when dynamic extreme load were applied to the specimen.

• International Journal of Automotive Technology
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• 제4권1호
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• pp.31-40
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• 2003

W-beam guardrail system has been the most popular roadside safety device around the world. Through large plastic deformation and corresponding energy dissipation, a W-beam guardrail system contains and re-directs out-of-control vehicles so as to reduce the impact damage on the vehicle occupants and the vehicles themselves. In this paper, our recent experiments on 1 : 3.75 downscaled W-beam and the beam-post system are reported. The static and impact test results on the load characteristics, the global response and the local cross-sectional distortion are reveled. The effects of three different end-boundary conditions for the beam-only testing are examined. It is found that the load characteristics are much dependent on the combined contribution of the local cross-sectional distortion and the end-supporting conditions. The energy Partitioning between the beam and the supporting Posts in the beam-Post-system testing were also examined. The results showed that the energy dissipation partitioning changed with the input impact energy. Finally, a simple mass-spring model is developed to assess the dynamic response of a W-beam guardrail system in response to an impact loading. The model's prediction agrees well with the experimental results.

• Earthquakes and Structures
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• 제13권4호
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• pp.409-419
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• 2017

In order to analyze the vibration control effect of viscous damper in the concrete archaized buildings with lintel-column joints under seismic action, 3 specimens were tested under dynamic excitation. Two specimens with viscous damper were defined as the controlled component and one specimen without viscous damper was specified as the non-controlled component. The loading process and failure patterns were obtained from the test results. The failure characteristics, skeleton curves and mechanical behavior such as the load-displacement hysteretic loops, load carrying capacity, degradation of strength and rigidity, ductility and energy dissipation of the joints were analyzed. The results indicate that the load-bearing capacity of the controlled component is significantly higher than that of the non-controlled component. The former component has an average increase of 27.4% in yield load and 22.4% in ultimate load, respectively. Meanwhile, the performance of displacement ductility and the ability of energy dissipation for the controlled component are superior to those of the non-controlled component as well. Compared with non-controlled component, equivalent viscous damping coefficients are improved by 27.3%-30.8%, the average increase is 29.0% at ultimate load for controlled component. All these results reflect that the seismic performance of the controlled component is significantly better than that of the non-controlled component. These researches are helpful for practical application of viscous damper in the concrete archaizing buildings with lintel-column joints.

• Structural Engineering and Mechanics
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• 제52권3호
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• pp.559-572
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• 2014

This paper presents the results of an experimental investigation on the flexural behavior of doubly reinforced lightweight concrete (R.L.C.) beams tested under cyclic loading. A total of 20 beam specimens were tested. Test results are presented in terms of ductility index, the degradation of strength and stiffness, and energy dissipation. The flexural properties of R.L.C. beam were compared to those of normal concrete (R.C.) beams. Test results show that R.L.C. beam with low and medium concrete strength (20, 40MPa) performed displacement ductility similar to the R.C. beam. The ductility can be improved by enhancing the concrete strength or decreasing the tension reinforcement ratio. Using lightweight aggregate in concrete is advantageous to the dynamic stiffness of R.L.C. beam. Enhancement of concrete strength and increase of reinforcement ratio will lead to increase of the stiffness degradation of beam. The energy dissipation of R.L.C beam, similar to R.C. beam, increase with the increase of tension reinforcement ratio. The energy dissipation of unit load cycle for smaller tension reinforcement ratio is relatively less than that of beam with higher reinforcement ratio.

• 대한기계학회논문집B
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• 제28권10호
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• pp.1255-1263
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• 2004

An a priori test has been conducted for the dynamic mixed model which was generalized for the prediction of passive scalar field in a turbulent channel flow The results from a priori tests indicated that dynamic mixed model is capable of predicting both subgrid-scale heat flux and dissipation rather accurately. The success is attributed to the explicitly calculated resolved term incorporated into the model. The actual test of the model in a LES a posteriori showed that dynamic mixed model is superior to the widely used dynamic Smagorinsky model in the prediction of temperature statistics.

• 한국전산구조공학회논문집
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• 제15권2호
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• pp.197-207
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• 2002

본 연구에서는 죄굴이 방지된 비부착 가새가 설치된 철골조 건물의 에너지 소산능력과 지진응답에 대하여 연구하였다. 먼저 조화하중을 받는 단자유도계 구조물을 대상으로 변수분석을 수행하고 가새의 최적항복강도를 구하였다. 다자 유도계 골조구조물의 비선형 시간이력 해석을 통하여 다양한 크기와 강도를 가진 가새가 설치된 구조물의 지진응답을 분석하고, 가새의 적당한 층별 분배방법을 찾기 위하여 여러 가지 분배방법을 적용하였다. 해석결과에 따르면 일반적으로 가새의 강성이 증가함에 따라 구조물의 최대변위는 감소하였다. 그러나 구조물의 고유주기 및 하중에 따라 가새의 강성이 커짐에 따라 구조물의 최대 변위와 누적된 손상이 증가하는 것으로 나타났다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제16권11호
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• pp.1051-1055
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• 2010

소프트웨어 라디오는 기존에 특화된 하드웨어 칩으로 구현되던 무선 통신 프로토콜을 소프트웨어로 구현하여 실행하는 기술이다. 새로운 프로토콜의 적용과 기존 프로토콜의 수정이 동적인 프로그래밍만으로 가능해지기 때문에 무선 통신 기술의 새로운 패러다임의 변화를 가져왔다. 하지만, 소프트웨어 라디오 시스템은 범용 프로세서와 통신 하드웨어를 동시에 장착하고 있기 때문에 그만큼 전력 소모가 크다. 본 논문에서는 이러한 소프트웨어 라디오 시스템을 위한 전력 관리 기법인 복합 변조/전압 스케일링 기법을 제안한다. 그리고 제안된 기법의 전력 절감 효과를 수치적인 결과를 통해 분석한다. 결과적으로 복합 변조/전압 스케일링 기법은 주어진 데이터 전송률을 충족시키면서 무선 통신의 변조 레벨과 프로세서의 전압을 효율적으로 조절하여 전력 소모를 최소화시킨다.