• Proceedings of the Korean Information Science Society Conference
• /
• 2004.10c
• /
• pp.133-135
• /
• 2004

IEEE 802.11 표준에서 지원하는 전력절감모드(Power-Saving Mode)의 실제 전력 효율성과 통신 성능의 차이를 다양한 트랙픽 환경에서 실험한다. 그리고 전력절감모드로 운영 중인 스테이션이 다른 스테이션의 통신 성능에 미치는 영향도 조사한다. 일반적으로 전력절감모드는 전력 소비면에서는 효율적이지만 통신성능을 저하시킨다. 그러나 트래픽의 종류에 따라 통신 성능의 저하에는 차이가 발생하며 별도의 혼잡제어를 하지 않는 트래픽의 경우에는 전력절감모드의 운영이 성능면에서 의미가 있음을 확인하였다.

• Proceedings of the Optical Society of Korea Conference
• /
• 2003.07a
• /
• pp.240-241
• /
• 2003

경계면 근처에서의 에바네슨트파의 상호작용은 입사, 반사 및 굴절된 평면파의 삼중모드로 설명한다. 경계에서 굴절률이 낮은 영역에 위치한 DCM 색소분자에 의한 자발방출은 굴절률이 높은 영역에서 입사된 삼중모드와 굴절률이 낮은 영역에서 입사한 삼중모드와 상호작용을 하며, 광 측정기에서는 이 두 모드의 선형결합을 보게된다. 자발방출에 대한 실험결과는 이러한 이론을 뒷받침 해준다. (중략)

• Proceedings of the Acoustical Society of Korea Conference
• /
• 1998.06e
• /
• pp.103-106
• /
• 1998

본 논문은 상용 FEM-BEM 프로그램을 사용하여 점-조화 가진(harmonic point excitation)에 의한 자유지지 경계 조건을 갖는 원통 셸(cylindrical shell)의 방사 효율(radiation efficiency) 실험의 결과와 비교하였다. 우선 충격 해머 실험(impact hammer test)을 통한 모드 시험(modal testing)으로 원통 셸의 공진 주파수(natural frequency)와 모드 형상(mode shape)의 특징을 살펴보고 다음으로 점-조화 가진에 의한 원통 셸의 방사 효율을 SYSNOISE와 ANSYS로 해석해 보았다. 동시에 음향 세기 실험을 통한 방사 효율을 측정하여 전산 해석의 결과와 실험의 결과를 비교해 보았다.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2010.04a
• /
• pp.183-186
• /
• 2010

교각에서의 기초세굴 단계 및 상부구조물의 영향에 따른 진동특성을 파악하기 위해 교각 시험체를 이용하여 충격진동실험과 Midas FEA ver.2.0를 이용한 유한요소해석을 수행하였다. 기초세굴 모의는 교각시험체 기초 주위의 지반을 단계별로 굴착하였으며, 상부구조물의 영향은 철근콘크리트 블록을 제작하여 교각 시험체 위에 재하하였다. 충격진동실험과 수치해석결과, 강성이 작아지거나 질량이 커질수록 1차 모드 고유진동수도 작아지는 등 유사한 경향을 나타내었다. 대체적으로 충격진동실험으로 구한 1차모드 고유진동수는 수치해석으로 구한 값보다 작은 경향을 나타내었으며, 이는 지반의 강성변화를 수치해석 모델에서 연속적으로 반영하지 못하는 한계로 인해 발생한 오차로 판단된다. 따라서 1차 모드 고유진동수의 변화를 이용한 교각 세굴 건전성 평가를 위한 유한요소해석을 위해서는 지반물성을 보다 잘 모의할 수 있는 기법의 개발이 필요하였다.

• Journal of the Korean Geotechnical Society
• /
• v.22 no.12
• /
• pp.15-24
• /
• 2006

The evaluation of shear modulus is very important in various fields of civil engineering. Non-destructive seismic methods can be used to determine shear wave velocity ($V_s$) profile. Non-destructive seismic methods geneally consist of three steps: field testing, evaluation of dispersion curve, and determination of Vs profile by inversion process. Non-destructive seismic methods can be divided into two categories according to the number of receivers used for data reduction: two-channel tests and multi-channel tests. Two channel tests use apparent velocity dispersion curve and multi-channel tests use mode dispersion curves. Multi-channel tests using mode dispersion curve can reduce calculation time to determine soil profile and uncertainties in inversion process. So far, only multi-channel tests can determine mode dispersion curves but multi-channel test needs many receivers to determine reasonable mode dispersion curves. In this paper, HWAW (Harmonic Wavelet Analysis of Wave) method is applied to determine mode dispersion curves. HWAW method uses short test setup which consists of two receivers with a spacing of 1 to 3 m. Through numerical simulations and field application, it is shown that HWAW can determine resonable mode disperson curves.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2017.10a
• /
• pp.223-226
• /
• 2017

With the development of information technology, users are provided with information they want through mobile device in various situations. When users communicate with information, there is interaction through gesture activities such as tapping and experience in the process. Experience through interaction in mobile affect the user's psychology. This is important because it is related to the behavior of the user in the future. Various types of information presentation methods have been researched in mobile environment. However, there are more research focusing on functional interactivity. The purpose of this study is to investigate the effect of interaction and usage mode on satisfaction, usefulness, and intention to use for sound text presentation that is user-centered. As variables for my study, there are two factors which are interactivity and usage mode. The interactivity type is composed of two ways that are: High and Low depending on modality and message interactivity; and the usage mode is composed of Action mode and Goal mode depending on whether user has a task or not. The experimental design is $2{\times}2$. The same content is provided in (a) only Modality interactivity, and (b) Modality and Message interactivity are provided. Depending on usage mode, (a) Action mode is processed without a specific task, and (b) Goal mode is performed with a specific task to participants. The experimental study demonstrated that there is a difference in satisfaction, usefulness, and intention to use depending on the difference of interaction and usage mode when providing information in mobile environment. The results of this study are summarized as follows: interaction and usage mode have significant influence on mobile user's satisfaction, usefulness, intention to use.

• The Journal of the Convergence on Culture Technology
• /
• v.9 no.6
• /
• pp.1049-1055
• /
• 2023

The utilization of agricultural drones for pest control operations has been increasing due to its economic efficiency. However, variations in the effectiveness of these operations occur depending on the operator's proficiency. In this study, we applied a smart operating mode to overcome the limitations of manual flight mode and proposed a numerical model. Through comparative validation with prior research, we conducted experimental verification. As a result, we determined the spray time and calculation of spray area for each drone model. We selected a drone for pest control with a high similarity to the numerical model and verified it experimentally. Through this, we confirmed that the application of the smart operating mode is more effective in terms of calculation of spray area and operational efficiency compared to manual flight mode.

• Journal of the Society of Disaster Information
• /
• v.9 no.4
• /
• pp.400-412
• /
• 2013

For the composite behavior of steel tube and inner concrete, the shear connectors should be applied to the CFT structures. However, the present design codes don't provide the design criteria that can be applied on shear connectors in the CFT structures typically filled with plain concrete. This study has been carried out to propose design criteria (shear strength and resistance factor) for the stud shear connectors in CFT structures. Experimental tests using the push-out specimens with the plain concrete blocks and finite element analysis were conducted for the purpose of verifying the main failure mode to propose the shear strength of studs in CFT structures. From the results of this study, the main failure mode of studs in CFT structures is splitting crack of concrete and this failure mode reduces shear strength of studs in CFT structures relatively to those embedded in RC blocks.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2008.04a
• /
• pp.89-92
• /
• 2008

This study investigates the shear behavior of architectural masonry veneer wall reinforced with specific reinforcement details proposed by this study. For this purpose, experimental tests were conducted using one un-reinforced masonry(URM) wall specimen and three reinforced masonry(RM) wall specimens under quasi static cyclic loads. Un-reinforced(plain) masonry wall is expressed that behavior and failure mode are different for aspect ratio(L/H) and axial compressive force. The test variables are wall aspect ratio and presence of reinforcement. These specimens are masonry structure for architectural clading that is not to exist the axial compressive force. thus the axial compressive force is excepted from test variable. Test result, Behavior of specimens are dominated over rocking mode, but final failure modes are combined with different behaviors. And FEMA273 has proposed the equation of shear strength of masonry pier subjected to in-plane loading. Shear strength equations are classified four types of failure mode that is Rocking, and Toe-Crushing, Bed-Joint-Sliding and Diagonal-Tension. FEMA273 equations predict the behavior modes well, but shear strength is shown in different result.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.20 no.2
• /
• pp.218-227
• /
• 2014

In this paper, it performed to the elastic-plastic large deflection series analysis using the experimental model and predicted a failure mode and ultimate strength. The collapse mode of numerical analysis model is formed a plastic hinge on loaded flange and consistent with the collapse mode of experimental model. Also, The yield line is formed in the web could observed that have occurred the crippling collapse mode and the ultimate loads of the experimental model and numerical analysis model have maintained linearly Means 1.07, Standard deviation 0.04, Coefficient of variation(COV) 0.04 and the result of ultimate loads have appeared approximately 8% error rate. it was found that very satisfied to the experimental results and the applied rules. if it is considered to be maintain a reasonable safety level, it is possible to predict the failure modes of aluminium alloy plate girders and ultimate loads.