• Journal of the Korea Society for Simulation
• /
• v.18 no.4
• /
• pp.1-8
• /
• 2009

The distributed war-game simulation system has been used to represent the virtual battlefield environment. In order to produce a simulation result, simulators connected from a network transfer messages with location information of simulated objects to a central simulation server. This network traffic is an immediate cause of system performance degradation. Therefore, the paper proposes a system to manage and control network traffic generated from distributed war-game simulation. The proposed system determines the moving distance of simulated objects and filters location messages by a distance threshold which is controlled according to system conditions like network traffic and location error. And, the system predicts the next location of simulated objects to minimize location error caused by message filtering. Experimental results demonstrate that the proposed system is effective to control the network traffic of distributed war-game simulation systems and reduce the location error of simulated objects.

• The Korean Journal of Rheology
• /
• v.5 no.2
• /
• pp.125-135
• /
• 1993

고밀도 폴리에틸렌(High density polyethlene, HDPE)내에 차단성 수지인 나일론 (Nylon)이 분산된 블렌드의 모폴로지와 유기 용제에 대한 차단성에 대해 연구하였다. 나일 론이 구형, 실린더 및 판상 구조 형태를 가지며 분산된 블렌드를 가공조건을 변화시켜 제조 하였다. 블렌드의 모폴로지가 유기 용제의 차단성에 끼치는 영향을 알아보기 위하여 투과시 험을 하였으며 수치 모사를 통하여 투과도를 이론적으로 예측해 보았다. 동일한 나일론양에 서 분산상인 나일론이 구형 또는 실린더 형태를 갖는 경우 투과액에 대해 낮은 차단성을 보 이는데 반하여 판상구조를 갖게되는 경우에는 차단성이 크게 상승함을 관찰할수 있었다. 이 는 판상구조형태를 취함으로써 블렌드내에서의 투과액의 투과경로가 길어졌기 때문이다. 나 일론 층의 여러기하학적인 형태변화에 대해 GRM관계식 및 이를 수정한 식을 이용하여 투 과도를 예측하여 보았다. 나일론층의 중첩도가 높다고 가정한 경우가 중첩도를 낮게 생각한 경우에 비해 높은 차단성을 보임을 수정된 GRM 관계식을 통하여 알 수 있었다. 또한 나일 론 층의 폭이 증가할수록 그리고 두께가 감소할수록 높은 차단효과를 보임을 예측 할 수 있 었다.

• Korean Journal of Environment and Ecology
• /
• v.27 no.1
• /
• pp.64-70
• /
• 2013

To examine the proportion of secondary seed dispersion by wildlife and to identify the related wildlife, We measured seed removal rates and related wildlife at the natural mixed broadleaved forest in mountain Jungwang, Pyeungchang-gun in middle part of Korean peninsula, seed-tray contained four kind of tree seeds were setted from mid-september to late-October for three years. Mean seed removal rates(MSRR) of acorn(Q. mongolica)is shown the highest values 87.2%, next MSRR of samara(A. pseudosieboldianum) does 33.1%, MSRR of samara(A. pictum subsp. mono) does 29.2%. and then SRR of samara(A. mandshuricum) does only 13.6%. Acorns are removed more faster than samaras. Among the related wildlife, Siberian chipmunks most freqently visit seed tray, and ordered Korean squirrel, Wild boar, and Yellow-throated marten. Most secondary dispersed acorns might be consumed by Wild boar, and small portions does comsumed or scatter-hoarded by rodents. Most secondary dispersed samaras might be consumed by rodents, and small portions does scatter-hoarded by rodents. A few sound seeds are remained on the forest floor in late October owing to the seed consunption and seed hoarding by wildlife. We observe seedling establishment of four broadleaved tree species. From these results, We proved Wild boar is seed comsummer, and rodents are seed consummer and seed disperser. Further studies on secondary seed dispersion, seed consumption and hoarding and related wildlife should be needed.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.8 no.2
• /
• pp.386-393
• /
• 2004

In order to maintain load balancing in distributed systems in a decentralized manner, every node should obtain workload information from all the nodes on the network. It requires $Ο({v^2})$ traffic overheads, where v is the number of nodes. This paper presents a new synchronous dynamic distributed load balancing algorithm for a ( v,k+1,1)-configured network topology, which is a kind of 2k regular graph, based on symmetric balanced incomplete block design, where v equals ${k^2}+k+1$. Our algorithm needs only Ο(v√v) message overheads and each node receives workload information from all the nodes without redundancy. And load balancing in this algorithm is maintained so that every link has same amount of traffic by √v for transferring workload information.

• 건축구조
• /
• v.12 no.4
• /
• pp.88-89
• /
• 2005

육교에 하중이 재하되었을 때 실제 구조부재들은 하중을 어떻게 효과적으로 분산시키며 이 분산시킨 힘들은 결국 어디로 모이고 각각의 부재는 어떤 현상이 발생하는지 알아보고 구조해석 프로그램 마이다스를 이용하여 구조해석을 하여 이들의 상관관계를 알아 본다.

• Journal of The Korean Association of Information Education
• /
• v.2 no.2
• /
• pp.269-277
• /
• 1998

In most of the distributed deadlock detection algorithms using messages called probes, only a portion of the generated messages are effectively used, and hence the wasted probes cause heavy communication traffic. In this paper, a distributed deadlock detection algorithm is proposed which can efficiently detect deadlocks making use of those residue probes. Our algorithm is complete in the sense that they detect not only those deadlocks in which the initiator is involved as most other algorithms do, but all the other deadlocks that are present anywhere in a connected wait-for-graph. To detect all the deadlocks, the algorithms known to be most efficient require O(ne) messages, where e and n are the number of edges and nodes in the graph, respectively. The single execution of the presented algorithm can accomplish the same task with O(e) messages.

• Polymer(Korea)
• /
• v.30 no.1
• /
• pp.50-55
• /
• 2006

When the monodisperse polystyrene(PS)/HDDA polymer particles were synthesized via one-step polymerization using polystyrene seed particles by dispersion polymerization, the effects of 1) the molecular weight of seed polymer particles, 2) the ratio of the absorbed HDDA to the seed polymer particles (swelling ratio) and 3) seeded polymerization rate on the surface morphology of PS/HDDA polymer particles were investigated. It was observed that the creation of the crater shaped defect on the surface of PS/HDDA polymer particles was irrespective of the molecular weight of seed polymer ant swelling ratio. But its surface morphology could be controlled by the change of the seeded polymerization rate.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.33 no.5
• /
• pp.1785-1795
• /
• 2013

Most of the previous models for analysis of shallow water flow assumed the uniform velocity distributions over the flow depth so that they produced incorrect velocity prediction at meandering part due to the ignorance of secondary current. In this study, the vertical velocity profiles in longitudinal and transverse direction were decomposed as the mean and variation components, which resulted in additional dispersion stresses terms in momentum equations. The proposed model were applied at the channels with $30^{\circ}$, $90^{\circ}$, $270^{\circ}$ bends, and shallow water flow in curved channel was analyzed using dispersion stresses. The dispersion stresses acted as a sink or source in the momentum equations, which caused the transverse convection of momentum to shift from the inner bank to the outer bank.

• Review of KIISC
• /
• v.2 no.4
• /
• pp.17-29
• /
• 1992

본 논문에서는 시스템 내의 모든sote들에게 분산되어 있는 정보들을 수렴하여 일치를 이루고, 그 결과를 모든 site들이 알도록 하는 다중 일치 프로토콜을 위한 효과적인 통신 방법을 제안하고자 한다. 분산 시스템에 참여하는 computer 또는 site들의 수를 N이라 할때, $O(N^2)$의 message를 필요로하면서 한 round안에 일치를 이룰 수 있는 프로토콜은 message의 수가 너무 많다는 것이 단점이다. 이에 본 논문에서는 Finite Projective Planes을 이용하여 message의 수를 줄이면서 두 round 안에 일치를 이룰 수 있는 통신 방법을 제안한다. 이때, 각 round마다 필요한 message의 수는 O(N$)이다. 또한, 이 통신 방법에서 이용되는 Finite Projective Planes을 구축하는 알고리즘을 제안하고자한다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
• /
• 1992.11a
• /
• pp.71-80
• /
• 1992

본 논문에서는 시스템내의 모든 site들에게 분산되어 있는 정보들을 수렴하여 일치를 이루고, 그 결과를 모든 site들이 알도록 하는 다중 일치 알고리즘을 위한 효과적인 통신 방법을 제안하고자 한다. 분산 시스템에 참여하는computer또는 site들의 수를 N이라 할 때, O($N_2$)의 message를 필요로 하면서 한round안에 일치를 이룰 수 있는 알고리즘은 message의 수가 너무 많다는 것이 단점이다. 이에 본 논문에서는 Finite Projective Planes를 이용하여 message의 수를 줄이면서 두 round안에 일치를 이룰 수 있는 통신 방법을 제안한다. 이때, 각round마다 필요한 message의 수는 O(N√N)이다. 또한, 이 통신 방법에서 이용되는 Finite Projective Planes을 구축하는 알고리즘을 제안하고자 한다.