• 한국정밀공학회지
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• 제20권7호
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• pp.84-90
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• 2003

This paper develops a control method that is composed of the proportional control algorithm and the learning algorithm based on the recurrent neural networks (RNN) for the position control of a pneumatic rodless cylinder. The proportional control algorithm is suggested for the modeled pneumatic system, which is obtained easily simplifying the system, and the RNN is suggested for the compensation of the modeling errors and uncertainties of the pneumatic system. In the proportional control, two zones are suggested in the phase plane. One is the transient zone for the smooth tracking and the other is the small movement zone for the accurate position control with eliminating the stick-slip phenomenon. The RNN is connected in parallel with the proportional control for the compensation of modeling errors and frictions, compressibilities, and parameter uncertainties in the pneumatic control system. This paper experimentally verifies the feasibility of the proposed control algorithm for such pneumatic systems.

• 대한산업공학회지
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• 제29권4호
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• pp.292-303
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• 2003

An efficient mobility management for mobile stations plays an important role in mobile communication network. Two basic operations of mobility management are location registration and paging. A zone-based registration (ZBR) is implemented in most of mobile communication systems and we consider the mobility management scheme that combines a zone-based registration and a selective paging (SP). We propose new analytical model that can reflect on the characteristics of the ZBR based on 2-dimensional random walk mobility model and more efficient paging schemes considering the proposed model. We evaluate the performance of the mobility management scheme with our mobility model to determine the optimal size of location area that will result in the minimum signaling traffic on radio channels. Numerical results are provided to demonstrate that our mobility model is useful to evaluate the ZBR more exactly.

• 대한치과보철학회지
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• 제54권4호
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• pp.407-412
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• 2016

심하게 흡수된 치조제를 지닌 환자에게 적절한 의치를 제공하기 위한 한 가지 방법으로써 중립대 인상 기법을 이용한 의치의 제작을 고려해 볼 수 있다. 중립대 내에 인공 치아를 배열하는 것은 다음의 두 가지 목적을 이루고자 함이다. 첫째, 치아가 정상적인 근육의 기능을 방해하지 않도록 하기 위함이며, 둘째, 의치에 저항하여 가해지는 근육 조직의 힘이 안정과 유지에 더 유리하게 작용할 수 있도록 하기 위함이다. 본 증례의 환자는 심한 잔존 치조제의 흡수를 보이는 78세 여자 환자로 오랜 기간 불안정한 상 하악 총의치를 사용하고 있었다. 의치의 안정과 유지를 향상시키기 위하여 중립대 인상 기법을 통한 새로운 의치의 제작을 계획하였다. Modeling compound를 이용하여 중립대를 인기하였으며 치아 배열 후 external impression을 시행함으로써 정확한 연마면을 형성할 수 있었다. 완성된 상 하악 총의치는 보다 향상된 안정과 유지를 보였으며 환자 역시 새로 제작된 의치에 만족감을 보였기에 이를 보고하고자 한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2009년도 춘계 학술발표회
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• pp.278-287
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• 2009

This thesis studied effect of zoning on seepage flow in concrete faced gravel-fill dam (CFGD) designed to have selected main rockfill or gravel-fill zone, Zone 3Bs with higher permeability to enhance the safety against accidental water infiltration into the dam. For this purpose, centrifuge model tests with two cases, with and without Zone 3Bs, were performed in order to investigate the necessity and the function of Zone 3Bs. Model dams were made by soil samples with modified coefficients of permeability and concrete faced slab was simulated with aluminum alloy. Water infiltration was simulated by rising water table over cracks on the facing. Behaviors of model dams were measured by LVDTs, strain gages, pore water pressures and cameras. Form the results of centrifuge tests, it was found out that the Zone 3Bs acts as a protection of main gravel-fill zone by inducing flow paths for infiltrated water into it as well as by draining off the infiltrated water out of the dam in a short time.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2000년도 봄 학술발표회논문집
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• pp.317-323
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• 2000

The purpose of this study is to compare the seismic resistant capacity inherent in ductile moment resisting frames using two different joint modeling. The difference between these two models is the capability for considering the panel zone deformation. For this purpose, 5 story steel moment frame is designed in compliance to the Korean seismic design provisions and the steel structure design standard. Nonlinear Static Procedure(NSP) and Nonlinear Dynamic Procedure(NDP) of this structure are carried out using two different joint models. Based on the results of NSP and NDP, the sensitivity of the response to analytical modeling is appraised. Also, it is proposed that for the highrise steel structures, the joint deformation should be accounted properly by the analytical model.

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 1996년도 학술발표회
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• pp.15-18
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• 1996

A general description of sprinkler activation time in compartment-fire-generated smoke layers is made. For calculation of the time hot layer temperature is obtained from two-layer zonal model and time constant of sprinkler is measured. Upper-layer thickness at the instant of sprinkler activation is also presented with changes of opening area. The outputs of the present study provide inputs for the interaction modeling of sprinkler spray and compartment fire environment, which simulates fire suppression phenomena.

• 한국해안·해양공학회논문집
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• 제22권5호
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• pp.333-343
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• 2010

목포해역에서 조위와 조류 관측자료를 분석하여, 낙조류 우세 조류특성을 보이는 것을 확인하였으며 낙조류 우세를 발생하는 물리적 요인에 대해 검토하였다. 노출한계수심, 바닥마찰응력 산정방법, 해안 매립, 조석의 진폭, 비선형 조석, 와점성계수와 목포해역의 낙조류 우세현상의 관련성에 대해서 2차원 해수유동 모형을 적용하여 자세히 조사하였다. 다양한 조건에 대한 모의결과로부터 노출한계수심과 와점성계수는 모의결과에 거의 영향을 주지 않으며, 바닥마찰응력이 증가함에 따라 조류의 비선형성이 증가하여 낙조류 우세현상이 나타나는 것을 확인할 수 있었다. 간사지가 미치는 영향은 간사지가 육지로 바뀌면 낙조류 우세가 심해지고, 간사지가 바다로 바뀌면 낙조류 우세가 사라지는 것을 확인할 수 있었다. 그동안 목포해역에서 진행되어온 해안매립사업은 낙조우세현상을 심화시켜 왔음을 확인할 수 있었으며, 비선형 조석은 비대칭 조류를 생성하는 데 결정적인 역할을 하여 조류의 비대칭성인 강한 목포해역에서 조류를 모의할 때는 개방경계 조위에 비선형조석을 포함해야 함을 확인할 수 있었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.438-440
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• 2003

This study is introducing a new approach of ATInSAR hologram for modeling wave refraction spectra pattern. TOPSAR data with L$_{-HH}$ and C-vv bands utilized spatial variation of wave refraction. Based on the phase information in along track interferometry, and ATInSAR hologram the quantitative information such swell wave height and spectra energy have been modeled. The phase information in ATInSAR hologram images can be transferred to wave refraction The ATInSAR hologram can be used to investigate the wave refraction pattern along the coastal waters. The fringe information pattern was shown to be useful in modeling wave refaction spectra varaition. The hologram interferometry wave refraction model consists of two sub-models. The purpose of first sub-model is to determine the swell wave height by using ATInSAR. Second sub-model aims to generate the holographic interferometry from the information of two wave spectra which detected by ATInSAR technique. The azimuth cut-off variations along the fringe patterns will be estimated. As azimuth cut-off contains the wave height information which could be used the significant wave height variation in convergence and divergence zone.

• 한국태양에너지학회 논문집
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• 제31권4호
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• pp.1-8
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• 2011

In this paper, inverse building modeling was applied to building perimeter zones which have different window orientation. Two test zones of east-facing and west-facing zones in ERS(Energy Resource Station) building, which is representative of small commercial building, was used to test performance of cooling load calculation and peak cooling load reduction. The dynamic thermal load model for the east and west zone was validated using measured data for the zones and then it was used to investigate the effect of peak cooling load reduction by adjustment of indoor cooling temperature set points during on-peak time period. For the east zone, the peak load can be reduced to about 60% of the peak load for conventional control even without any precooling. For the west zone, PLR is nearly independent of the start of the on-peak period until a start time of 1pm. Furthermore, PLR has a small dependence on the precooling duration. Without any precooling, the peak cooling load can be reduced to about 35% of the peak load associated with conventional control.

• 한국해양공학회지
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• 제22권2호
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• pp.78-84
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• 2008

As a preliminary step to build a complete superyacht hull design program, the development of superyacht profile design system is introduced. The two-dimensional hull profile is decomposed into four local zones depending upon the functionality and connecting continuity of the profile. Characteristics of each zone are investigated and used to generate the model describing the geometric shape of zone using freeform curves. A set of design parameters is derived from the established geometric model. Generation and modification of a model are is by manipulating the chosen parameters. Four zones designed are integrated to form a final profile. An interactive design system performing all the modeling and modification processes is implemented using the graphic user interface system based an Microsoft Foundation Class and OpenCASCADE, a open graphic library. The shapes of the profiles generated by the developed design system are verified with those of built superyachts. The developed design system will be used for the construction of three-dimensional superyacht hull modeling system.