• Structural Engineering and Mechanics
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• 제8권1호
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• pp.19-26
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• 1999

Superior performance of field consistent eight-node hexahedron element in static bending problems has already been demonstrated in literature. In this paper, its performance in free vibration is investigated. Free vibration frequencies of typical test problems have been computed using this element. The results establish its superior performance in free vibration, particularly in thin plate application and near incompressibility regimes, demonstrating that shear locking, Poisson's stiffening and volumetric locking have been eliminated.

• Journal of Communications and Networks
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• 제17권1호
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• pp.40-46
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• 2015

In a mobile ad hoc network (MANET), communication between mobile nodes occurs without centralized control. In this environment the mobility of a node is unpredictable; this is considered as a characteristic of wireless networks. Because of faulty or malicious nodes, the network is vulnerable to routing misbehavior. The resource constrained characteristics of MANETs leads to increased query delay at the time of data access. In this paper, AntHocNet+ Security (ANTSEC) framework is proposed that includes an enhanced cooperative caching scheme embedded with artificial immune system. This framework improves security by injecting immunity into the data packets, improves the packet delivery ratio and reduces end-to-end delay using cross layer design. The issues of node failure and node malfunction are addressed in the cache management.

• 한국군사과학기술학회지
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• 제17권3호
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• pp.327-335
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• 2014

In this paper, we propose a group distributed dynamic address assignment scheme suitable for tactical mobile ad hoc networks(MANET). Efficient address assignment is an important issue in the MANET because a node may frequently leave the current network and join another network owing to the mobility of the node. The conventional schemes do not consider the features of the tactical networks: existence of a leader node and network activity on a group basis. Thus, they may not be suitable for military operations. In our proposed scheme, called grouped units dynamic address assignment protocol(G-DAAP), a leader node maintains the address information for the members in the network and any of the nodes can exploit the information for the assignment or request of the IP address by a simple message exchange procedure. This leads to fast address assignment with small overheads. In addition, G-DAAP based on the modified IEEE 802.11e Enhanced Distributed Channel Access(EDCA) can assign addresses more quickly. We describe the delay performance of the G-DAAP and compare it with conventional schemes by numerical analysis and computer simulations. The results show that the G-DAAP significantly improves the delay performance as compared with the conventional schemes.

• 한국작물학회지
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• 제48권1호
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• pp.8-12
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• 2003

To find out the relationship between pod development and cytokinin contents during reproductive stage of peanut, the cytokinin contents, trans-zeatin ribo-side (t-ZR) and dihydrozeatin riboside (diZR), were investigated at 0, 7, 14, 21 and 28 days after flowering (DAF). The amounts of t-ZR and diZR in cotyledon and first branch among primary branches were 3, 448 pmol/g (FW) and 4, 824 p/g (FW), respectively, which were higher than those of other branches. The t-ZR and diZR contents of lower parts on the branch from cotyledon node at 7 DAF were 579 pmol/g (FW) and 2, 028 pmol/g (FW), respectively, which were higher than those of upper parts. The cytokinin contents of reproductive organs as flowering progressed were increased at 0 and 14 DAF on branch and position of node. The cytokinin contents of upper part with pruning the lower part on the branch from cotyledon node were high 112-337% at 7 DAF and 14 DAF compared with those of the control. In case of remove the upper part of the first internode on main axis, t-ZR contents was 4.7 times higher than diZR contents at 7 DAF. The pod setting rate of flower and position on the branch from cotyledon node was closely related to the cytokinin contents during floral reproductive stage.

• Journal of Information Processing Systems
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• 제19권6호
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• pp.803-816
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• 2023

Explainable artificial intelligence is a method that explains how a complex model (e.g., a deep neural network) yields its output from a given input. Recently, graph-type data have been widely used in various fields, and diverse graph neural networks (GNNs) have been developed for graph-type data. However, methods to explain the behavior of GNNs have not been studied much, and only a limited understanding of GNNs is currently available. Therefore, in this paper, we propose an explanation method for node classification using graph convolutional networks (GCNs), which is a representative type of GNN. The proposed method finds out which features of each node have the greatest influence on the classification of that node using GCN. The proposed method identifies influential features by backtracking the layers of the GCN from the output layer to the input layer using the gradients. The experimental results on both synthetic and real datasets demonstrate that the proposed explanation method accurately identifies the features of each node that have the greatest influence on its classification.

• 센서학회지
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• 제25권5호
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• pp.371-376
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• 2016

A self-powered piezoelectric energy harvester was developed for the application in wireless sensor node. The energy harvester was evaluated with power generation characteristics for the wireless sensor node for structural diagnosis of the electric power system. The self-powered wireless sensor node was set to measure temperature, vibration frequency of the electric power system. A piezoelectric harvester composed of 7 uni-morph cantilevers (functionalized as 6 generators and 1 vibration sensor) was connected to be an array and revealed to produce significantly high output power of approximately 10 mW at 120 Hz under 3.4 g((1 g = $9.8m/sec^2$). The wireless sensor node could work as the electric power generated by the developed piezoelectric harvester.

• 한국환경과학회지
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• 제29권4호
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• pp.423-434
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• 2020

The effects of amino acid and/or urea liquid fertilizer application on the growth and phytochemicals of Perilla leaves were summarized as follows; The fresh weight of the perilla leaves was in the order of CF, CL, KLF, and control, and 39.7 g, 37.4 g, 36.5 g and 32.3 g were measured. The plant height increased by 71.6 cm in the CF treatment than in the control(54.6 cm). The number of nodes was 14.3 node in CF treatment and 19% more than control(12 node). The vitamin C content tends to be increased by fertilizing the amino acid solution in the perilla leaf. The components of polyvalent unsaturation of n-6 origin were measured in CF treatment, KLF treatment, and control in 10.19 mg, 10.18 mg, and 9.38 mg per 100 g, respectively. Glutamic acid, aspartic acid, leucine, arginine, alanine and lysin were contained in perilla leaf amino acid. Glutaminic acid content was found to be 455.1 mg, 495.6 mg, and 478.8 mg in the control, KLF and CF treatment per 100 g, respectively. Effective nutrition management using amino acid fertilizer optimizes crop yield and profitability, it is important to reduce the negative environmental risks of using fertilizer.

• 한국정보통신학회논문지
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• 제20권12호
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• pp.2243-2251
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• 2016

본 연구에서는 트리구조를 가지는 네트워크의 [1,2]-지배집합에 대한 특성과 지배수의 상계 값에 대한 이론적 모형을 제시하였다. 구체적으로는 트리 네트워크가 가지는 몇 가지 전형적인 제약에 대해서 각 유형이 가지고 있는 지배집합의 지배수의 상계 값을 도출하였다. 본 논문에서는 트리구조의 네트워크에 대한 특성을 해석함에 있어서 그래프이론을 적용하였다. 노드집합 V와 링크집합 E으로 구성되는 그래프 G=(V,E)에 대해서 노드집합 V의 부분 집합 D를 가정한다. 이때 집합 V에 속하면서 집합 D에 속하는 않는 임의의 노드 ${\upsilon}$가 D에 속하는 노드와 1개 이상 2개 이하로만 인접하여 있으면 D를 [1,2]-지배집합이라 한다. 그리고 그래프 G의 [1,2]-지배집합 중 최소 농도를 [1,2]-지배 수라 하고 ${\gamma}_{[1,2]}(G)$로 표시한다. 본 논문에서는 트리(tree)의 [1,2]-지배 수에 대한 특성과 이의 새로운 상계 값을 증명하였다.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (C)
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• pp.336-340
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• 2007

We envisage that grid computing environments allow us to implement distributed data mining services, that is, those applications which analyze large sets of geographically distributed databases and information using the computational power and resources of a grid environment. This paper describes an experimental framework towards such a distributed data mining approach, including design considerations and a prototype implementation. Based on the "Knowledge Grid" architecture suggested by Cannataro et al., we identify four major components - user node, broker node, data node, and computation node - and define their individual roles. For implementing the prototype, we have investigated methods for utilizing distributed resources within a grid computing environment, e.g., communication and coordination among the various resources available.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.10-13
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• 2011

A level set method is proposed to simulate the incompressible two-phase flow considering the effect of surface tension. For reinitialization of level set junction, a direct approach method is employed, instead of solving hyperbolic type equation. A mixed element is adopted, so that the continuity mid Navier-Stokes equations are solved by using the quadratic elements (six-node triangular element mid nine-node quadrilateral element), mid the level set function is solved by using the linear elements (three-node triangular element mid four-node quadrilateral element). In order to verify the accuracy mid robustness of the codes, the present methods are applied to a few benchmark problems. It is confirmed that the present results are in good qualitative mid quantitative agreements with the existing studies.