• ETRI Journal
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• 제34권4호
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• pp.625-628
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• 2012

In this letter, a novel method for localizing a user in a smart home environment is presented. We propose a two-level structure, in which the first level determines an occupant's location in the block level using RSSI in a ZigBee network, while the second level accurately estimates the occupant's location using a particle filter to handle the variations in the signal strength measurement. We devise an experimental setup with people performing significant tasks in the smart home. The results obtained from the testbed indicate that the proposed model leads to an improvement in the mean distance error.

• 한국진공학회지
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• 제15권1호
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• pp.31-36
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• 2006

[ $Li/Ge(111)-3{\times}1$ ] 표면의 구조를 고찰하기 위해, Ge 3d core-level 광전자 스펙트럼을 분석하였다. Curve fitting을 통하여 스펙트럼에서 bulk Ge 3d peak에 해당하는 peak의 양쪽에 각각 하나씩의 표면 성분이 있음을 확인하였다. $Li/Ge(111)-3\times1$ 표면의 core-level spectrum에서의 두 표면 peak의 존재와 그 위치는 같은 금속에 의해 유도된 $Si/Ge(111)-3\times1$의 경우와 유사하며, 이는 두 표면의 구조fl서의 유사성을 시사한다. $Li/Ge(111)-3\times1$ 표면의 core-level 광전자 스펙트럼에서 보이는 두 개의 표면 성분의 존재와 위치는 알칼리 금속으로부터 유도되는 $Si/Ge(111)-3\times1$의 구조 모형으로 제안된 honeycomb-chain 모형과 잘 일치한다.

• Structural Engineering and Mechanics
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• 제13권5호
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• pp.465-478
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• 2002

This study lays emphasis on the development of efficient analytical models for a multistory structure with wings, including the in-plane deformation of floor slabs. For this purpose, a multistory structure with wings is regarded as the combination of multistory structures with rectangular plan and their junctions. In addition, a multistory structure with a rectangular plan is considered to be an assemblage of two-dimensional frames and floor slabs connecting two adjacent frames at each floor level. This modeling, concept can be easily applied to multistory structures with plans in the shape of L, T, Y, U, H, etc. To represent the in-plane deformation of floor slabs efficiently, a two-dimensional frame and the floor slab connecting two adjacent frames at each floor level are modeled as a stick model with two degrees of freedom per floor and a stiff beam with shear deformations, respectively. Three models are used to investigate the effect of in-plane deformation of the floor slab at the junction of wings on the seismic behavior of structures. Based on the comparison of dynamic analysis results obtained using the proposed models and three-dimensional finite element models, it could be concluded that the proposed models can be used as an efficient tool for an approximate analysis of a multistory structure with wings.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.191.1-191.1
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• 2014

Crystallization has become the most popular technique for the separation of enantiomers since the Pasteur's discovery. To investigate mechanism of crystallization of chiral molecules, it is necessary to study self-assembled structures on two-dimensional surface. Here, we have studied two-dimensional self-assembled structures of an unnatural amino acid, (S)-${\beta}$-methyl naphthalen-1-${\gamma}$-aminobutyric acid (${\gamma}^2$-1-naphthylalanine) on Au(111) surface at 150 K using scanning tunneling microscopy (STM). At initial stage, we found two chiral honeycomb structures which are counter-clockwise and clockwise configurations in one domain. The molecules are arranged around molecular vacancies, dark hole. By further increasing the amounts of adsorbed ${\gamma}^2$-1-naphthylalanine, a well-ordered square packed structure was observed. In addition, we found the other structure that molecules were trapped in the pore of the hexagonal molecular assembly.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2004년도 춘계학술대회논문집
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• pp.308-311
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• 2004

It is reported that there is a limit in increasing heavy-weight impact noise isolation performance of the load bearing wall system apartments to meet the regulation of the Ministry of Construction and Transportation (MOCT). To increase the heavy-weight impact noise isolation performance, improvement in structural systems such as increasing concrete slab thickness and application of rahmen structure were proposed. In this study floor impact sound levels from toil apartments with two rahmen structure multi-story residential buildings were measured before the construction of the buildings finished. Measurements were made at living room and two bedrooms at each apartment when the finishing processes were finished. The average value of light-weight impact sound level from ten apartments was 56dB (L'$\sub$n,Aw/). The heavy-weight impact sound level was 44dB (L'$\sub$i.Fmax.Aw/) and the impact sound level of the impact ball was 41dB(L'$\sub$i.Fmax.Aw/), As a result floor impact noises at the rahmen structure system were lower than the regulation level.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 1996년도 학술대회
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• pp.175-180
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• 1996

In this paper, a new image segmentation method based on merging of two low contrast neighbor regions iteratively is proposed. It is suitable for very low bit rate coding. The proposed method reduces efficiently contour information and preserves subjective and objective image quality. It consists of image segmentation using 4-level hierarchical structure based on mathematical morphology and 1-level region merging structure using the contrast difference of two adjacent neighbor regions. For each segmented region of the third level, two adjacent neighbor regions having low contrast difference value in fourth level based on contrast difference value is merged iteratively. It preserves image quality and shows the noticeable reduction of the contour information, so that it can improve the bottleneck problem of segmentation-based coding at very low bit rate.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1229-1232
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• 1996

This paper proposes the passive redundancy algorithm of multi-controller structure applicable to the steam generator level control system in the low power operating range. In the passive redundancy scheme of multi-controller structure, two suitable controllers exist if the plant is strongly stabilizable. One of the two controllers can be selected arbitrarily only if it is stable. In particular, this paper shows that the passive redundancy scheme can be efficiently used with PID and GPC control algorithms through simulation studies on the control of the steam generator.

• 한국해양공학회지
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• 제25권4호
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• pp.36-41
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• 2011

In the present paper, a direct forcing/fictitious domain (DF/FD) level set method is proposed to simulate the FSI (fluid-solid interaction) in two-phase flow. The main idea is to combine the direct-forcing/fictitious domain (DF/FD) method with the level set method in the Cartesian coordinates. The DF/FD method is a non-Lagrange-multiplier version of a distributed Lagrange multiplier/fictitious domain (DLM/FD) method. This method does not sacrifice the accuracy and robustness by employing a discrete ${\delta}$ (Dirac delta) function to transfer quantities between the Eulerian nodes and Lagrangian points explicitly as the immersed boundary method. The advantages of this approach are the simple concept, easy implementation, and utilization of the original governing equation without modification. Simulations of various water-entry problems have been conducted to validate the capability and accuracy of the present method in solving the FSI in two-phase flow. Consequently, the present results are found to be in good agreement with those of previous studies.

• 전자공학회논문지S
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• 제34S권11호
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• pp.102-113
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• 1997

In this paepr, a new image segmentation method reducing efficiently contour information causing bottleneck problem at segmentatio-based very low bit rate codingis proposed, while preserving objective and subjective quality. It consists of 4-level hierarchical image segmentation based on mathematical morphology and 1-leve region merging structure using contast of two adjacent regions. For two adjacent region pairs at the fourth level included in each region of the thid level, contrast is calculated. Among the pairs of two adjacent regions with less value than threshold, two adjacent regions having the minimum contrast are merged first. After region merging, texture of the merged region is updated. The procedure is performed recursively for all the adjacent region pairs at the fourth level included in each region of the third level. Compared with the previous method, the objective and subjective image qualities are similar. But it reduces 46.65% texture information on the average by decreasing total region number to be tansmitted. Specially, it shows reduction of the 23.95% contour information of the average. Thus, it can improve efficiently the bottleneck problem at segementation-based very low bit rate coding.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 추계학술대회 논문집
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• pp.17-22
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• 2008

Construction project have extremely high risk in the process of construction owing to unexpected event, like as design amendment. As a result, owner have to endure enormous extra-cost to control the risk and continue to the project having more higher uncertainty. Also, if the structure is completed, it is needed that the structure is protected and maintained continuously during life cycle time to satisfying original aim of structure itself. LCC analysis to calculate cost of structure alternatives divides into two stage, one is design_LCC and the other is maintenace_LCC. But two stages all is needed in the transition deterioration model to calculate more reasonable LCC analysis. This paper developed the model using analysis of FMS contents and survey from professional about Prestressed concrete beam girder bridge(PC Beam bridge)in railway. The model is focused in project level of PC beam because any condition state information for element level analysis can not get up. This paper is intended to use the developed model in LCC analysis of PC Beam bridge in railway and constitute the foundation to perform more deep study in the near future.