• Journal of the Korean Data and Information Science Society
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• 제23권3호
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• pp.587-593
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• 2012

We study Bayesian estimates for finite population proportions in multinomial problems. To do this, we consider a three-stage hierarchical Bayesian model. For prior, we use Dirichlet density to model each cell probability in each cluster. Our method does not require complicated computation such as Metropolis-Hastings algorithm to draw samples from each density of parameters. We draw samples using Gibbs sampler with grid method. We apply this algorithm to a couple of simulation data under three scenarios and we estimate the finite population proportions using two kinds of approaches We compare results with the point estimates of finite population proportions and their standard deviations. Finally, we check the consistency of computation using differen samples drawn from distinct iterates.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회B
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• pp.3197-3202
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• 2007

An analysis program for pedestrian flow has been developed to investigate the flow patterns of passenger in railway stations. Analysis algorithms for pedestrian flow based on DEM(Discrete Element Method) are newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. By using the developed program, we compared the simulation results of the effects of the location and size of exit and elapsed time.

• 한국철도학회논문집
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• 제8권4호
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• pp.337-341
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• 2005

Algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed. In the new algorithm, there are many similarity between multi phase flow and passenger flow. The velocity component of 1st phase corresponds to the direction vector of cell, each particle to each passenger, volume fraction to population density and the momentum equation of particle to the walking velocity equation of passenger, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger, To verify the effectiveness of new algorithm, passenger flow analysis for simple railway station model is conducted. The results for passenger flow in the model station are satisfying qualitatively and quantitatively.

• 한국철도학회논문집
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• 제9권3호
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• pp.271-276
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• 2006

Insight into behaviour of pedestrians as welt as tools to assess passenger flow condition is important in such instances as planning and geometric design of railway station under regular and safety-critical circumstances. Algorithm for passenger flow analysis based on DEM (Discrete Element Method) is newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. To verify the effectiveness of new algorithm, passenger flow analysis for the basic models of railway station is conducted.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2006년도 추계학술대회 논문집
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• pp.387-391
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• 2006

Insight into behaviour of pedestrians as well as tools to assess passenger flow conditions are important in for instance planning and geometric design of railway station under regular and safety-critical circumstances. Algorithm for passenger flow analysis based on DEM(Discrete Element Method) is newly developed. There are lots of similarity between particle-laden two phase flow and passenger flow. The velocity component of 1st phase corresponds to the unit vector of calculation cell, each particle to passenger, volume fraction to population density and the particle velocity to the walking velocity, etc. And, the walking velocity of passenger is also represented by the function of population density. Key algorithms are developed to determine the position of passenger, population density and numbering to each passenger. To verify the effectiveness of new algorithm, passenger flow analysis for the basic models of railway station is conducted.

• BMB Reports
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• 제44권1호
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• pp.1-10
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• 2011

Inter-cellular communication via diffusible small molecules is a defining character not only of multicellular forms of life but also of single-celled organisms. A large number of bacterial genes are regulated by the change of chemical milieu mediated by the local population density of its own species or others. The cell density-dependent "autoinducer" molecules regulate the expression of those genes involved in genetic competence, biofilm formation and persistence, virulence, sporulation, bioluminescence, antibiotic production, and many others. Recent innovations in recombinant DNA technology and micro-/nano-fluidics systems render the genetic circuitry responsible for cell-to-cell communication feasible to and malleable via synthetic biological approaches. Here we review the current understanding of the molecular biology of bacterial intercellular communication and the novel experimental protocols and platforms used to investigate this phenomenon. A particular emphasis is given to the genetic regulatory circuits that provide the standard building blocks which constitute the syntax of the biochemical communication network. Thus, this review gives focus to the engineering principles necessary for rewiring bacterial chemo-communication for various applications, ranging from population-level gene expression control to the study of host-pathogen interactions.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.1-10
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• 2004

Many bacteria monitor their population density and control the expression of specialized gene sets in response to bacterial cell density based on a mechanism referred to as quorum sensing. In all cases, quorum sensing involves the production and detection of extracellular signaling molecules, auto inducers, as which Gram-negative and Gram-positive bacteria use most prevalently acylated homoserine lactones and processed oligo-peptides, respectively. Through quorum-sensing communication circuits, bacteria regulate a diverse array of physiological functions, including virulence, symbiosis, competence, conjugation, antibiotic production, motility, sporulation, and biofilm formation. Many pathogens have evolved quorum-sensing mechanisms to mount population-density-dependent attacks to over-whelm the defense responses of plants, animals, and humans. Since these AHL-mediated signaling mechanisms are widespread and highly conserved in many pathogenic bacteria, the disruption of quorum-sensing system might be an attractive target for novel anti-infective therapy. To control AHL-mediated pathogenicity, several promising strategies to disrupt bacterial quorum sensing have been reported, and several chemicals and enzymes have been also investigated for years. These studies indicate that anti-quorum sensing strategies could be developed as possible alternatives of antibiotics.

• 한국지리정보학회지
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• 제12권4호
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• pp.74-83
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• 2009

기반시설부담구역 지정과 관련한 조항이 국토계획법에 신설되면서 정부는 2008년 9월 개정 시행령을 통해 인구증가율에 따른 기반시설부담구역 지정기준을 고시한 바 있다. 본 연구는 통탄신도시 조성으로 인구증가가 뚜렷한 화성시 동탄동을 사례지로 하여 격자 공간분석을 통해 법정 인구증가율 상회 격자 셀들을 선별해 보고 다시 이들에 대해 셀 버퍼와 셀 간격 등 두 가지 기준에 의한 그루핑 시나리오를 상정하여 공간적 인접성 단계별로 인구밀집이 예상되는 구역을 연동 집단화하는 방법에 대해 모의실험을 수행해 보았다. 이와 같이 선별한 동탄동 관내 가상 지정구역을 동탄동 토지이용계획도와 중첩하여 검토한 결과 위 두 가지 방식 모두에 있어 실제 인구집중 구역들이 적절한 형태로 집단화되는 것이 확인되었다.

• 폴리머
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• 제24권4호
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• pp.538-544
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• 2000

폴리프로필렌 수지를 연속공정으로 발포시킬 때의 공정 변수에 따른 발포체의 구조와 셀 형성에 관한 특성을 연구하였다. 본 실험에서 고려된 발포 공정 변수들은 발포제 함량, 핵제 함량, 다이 온도, 그리고 다이의 치수였다. 셀이 붕괴없이 성장하는데 있어서 발포제인 이소펜탄의 함량은 약 14.5 wt% 이하이었고, 그 이상의 발포 가스가 주입되었을 때에는 압출물이 팽창하는 가스 압력을 극복하지 못하여 셀이 붕괴되는 현상이 나타나며 불안정한 셀 구조를 형성하였다. 핵제는 1 wt%의 소량만으로도 핵제 없이 발포제만으로 생산된 발포체에 비해 약 1/7로 밀도가 감소하였고 셀 밀도는 핵제의 함량에 따라 4배 이상까지 비례하여 증가하였다. 또한, 본 실험에서 상대적으로 낮은 다이 온도였던 17$0^{\circ}C$에서 안정한 셀 구조를 형성하였다. 그러나, 다이 치수를 변화시켜 유도한 압력 감소 속도의 효과는 본 실험에서 두드러지게 나타나지 않았다.

• Asian-Australasian Journal of Animal Sciences
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• 제17권10호
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• pp.1338-1343
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• 2004

The Debao pony ear marginal tissue fibroblast cell line (NDPEM 2/2) was uccessfully established using either primary explant technique or collagenase technique. The characterizations of the cell line were identified as following: the cells were adherent and of density limitation; population doubling time (PDT) of cells made with the two techniques were 35.9 h and 48 h, respectively; chromosome analysis showed that the frequency of cell chromosome number to be 2n=64 was 91.3%-92.8%. Confirmed by isoenzyme analysis, this cell line had no cross- contamination. Tests for microbial contamination from bacteria, fungi, virus or mycoplasma were negative. This newly established cell line meets all the standard quality controls of ATCC. It will provide a precious genetic resource for the conservation of the Debao pony breed, as well as effective experimental material for genetic studies on Debao ponies.