• Journal of Internet Computing and Services
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• v.20 no.4
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• pp.91-102
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• 2019

In autonomous driving systems, the ability to classify pedestrians in images captured by cameras is very important for pedestrian safety. In the past, after extracting features of pedestrians with HOG(Histogram of Oriented Gradients) or SIFT(Scale-Invariant Feature Transform), people classified them using SVM(Support Vector Machine). However, extracting pedestrian characteristics in such a handcrafted manner has many limitations. Therefore, this paper proposes a method to classify pedestrians reliably and effectively using CNN's(Convolutional Neural Network) deep features and transfer learning. We have experimented with both the fixed feature extractor and the fine-tuning methods, which are two representative transfer learning techniques. Particularly, in the fine-tuning method, we have added a new scheme, called M-Fine(Modified Fine-tuning), which divideslayers into transferred parts and non-transferred parts in three different sizes, and adjusts weights only for layers belonging to non-transferred parts. Experiments on INRIA Person data set with five CNN models(VGGNet, DenseNet, Inception V3, Xception, and MobileNet) showed that CNN's deep features perform better than handcrafted features such as HOG and SIFT, and that the accuracy of Xception (threshold = 0.5) isthe highest at 99.61%. MobileNet, which achieved similar performance to Xception and learned 80% fewer parameters, was the best in terms of efficiency. Among the three transfer learning schemes tested above, the performance of the fine-tuning method was the best. The performance of the M-Fine method was comparable to or slightly lower than that of the fine-tuningmethod, but higher than that of the fixed feature extractor method.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.41 no.3
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• pp.71-82
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• 2004

Recently, network model inspired by social insect behavior attracts the public attention. The AntNet is an adaptive and distributed routing algorithm using mobile agents, called ants, that mimic the activities of social insect. In this paper. we present a new hardware architecture to realize an AntNet-based routing in practical system on a chip application. The modified AntNet algorithm for hardware implementation is compared with the original algorithm on the various traffic patterns and topologies. Implementation results show that the proposed architecture is suitable and efficient to realize adaptive routing based on the AntNet.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.11
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• pp.2205-2217
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• 2015

Bio-inspired routing protocol uses a principle of swarm intelligence, which finds the optimal path to the destination in a distributed and autonomous way in dynamic environments, so that it can maximize routing performances, reduce control overhead, and recover a path failure quickly according to the change of network topology. In this paper, we propose a bio-inspired routing protocol for mobile ad hoc networks. The proposed scheme uses a function of overhearing via wireless media in order to obtain the routing information without additional overhead. Through overhearing, the pheromone is diffused around the shortest path between the source and destination. Based on this diffused pheromone, a probabilistic path exploration is executed and the useful alternative routes between the source and destination are collected. Therefore, the proposed routing protocol can ensure the up-to-date routing information while reducing the control overhead. The simulation results show that the proposed scheme outperforms the typical AODV and AntHocNet protocols in terms of routing performances and significantly decreases the routing overhead against the AntHocNet.

• Journal of Communications and Networks
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• v.13 no.6
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• pp.583-590
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• 2011

Full-mesh IPSec tunnels pass through a black ("unsecure") network (B-NET) to any red ("secure") networks (RNETs). These are needed in military environments, because they enable dynamically changing R-NETs to be reached from a BNET. A dynamically reconfiguring security policy database (SPD) is very difficult to manage, since the R-NETs are mobile. This paper proposes advertisement process technologies in association with the tunnel gateway's protocol that sends 'hello' and 'prefix advertisement (ADV)' packets periodically to a multicast IP address to solve mobility and security issues. We focus on the tunnel gateway's security policy (SP) adaptation protocol that enables R-NETs to adapt to mobile environments and allows them to renew services rapidly soon after their redeployment. The prefix ADV process enables tunnel gateways to gather information associated with the dynamic changes of prefixes and the tunnel gateway's status (that is, 'down'/restart). Finally, we observe two different types of performance results. First, we explore the effects of different levels of R-NET movements on SP adaptation latency. Next, we derive the other SP adaptation latency. This can suffer from dynamic deployments of tunnel gateways, during which the protocol data traffic associated with the prefix ADV protocol data unit is expected to be severe, especially when a certain tunnel gateway restarts.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.195-208
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• 2023

This study aimed to use three-dimensional point cloud data (PCD) obtained from Terrestrial Laser Scanning (TLS) and Mobile Laser Scanning (MLS) to evaluate a deep learning-based species classification model for two tree species: Pinus koraiensis and Larix kaempferi. Sixteen models were constructed based on the three conditions: LiDAR platform (TLS and MLS), down-sampling intensity (1024, 2048, 4096, 8192), and deep learning model (PointNet, PointNet++). According to the classification accuracy evaluation, the highest kappa coefficients were 93.7% for TLS and 96.9% for MLS when applied to PCD data from the PointNet++ model, with down-sampling intensities of 8192 and 2048, respectively. Furthermore, PointNet++ was consistently more accurate than PointNet in all scenarios sharing the same platform and down-sampling intensity. Misclassification occurred among individuals of different species with structurally similar characteristics, among individual trees that exhibited eccentric growth due to their location on slopes or around trails, and among some individual trees in which the crown was vertically divided during tree segmentation.

• Journal of the Korea Society of Computer and Information
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• v.19 no.10
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• pp.91-97
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• 2014

In this paper, we design and implement a mobile game based on windows phone platform. Visual Studio and the Windows Mobile software development kit(SDK) and developer tool kits (DTK) make it possible to create software for the Windows Mobile platform in Visual C#. Also The XNA Framework is the set of .NET libraries that developers will code against to build games. XNA Framework support PC and XBOX and a ZUNE HD multiplex platform environment and 2D and 3D games provides the necessary functions to a development. XNA Framework is to make it easier to develop games because the codes which are succeeded creates with automatic, implements a game development relation resource and the game logic. The key idea of our game is that we use shooting and ranking system to raise fun.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1307-1312
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• 2015

As smart-phones become popular, mobile data traffic has been dramatically increasing and intensive researches on the next-generation mobile communication network is in progress to meet the increasing demand for mobile data traffic. In particular, heterogeneous network (HetNet) is attracting much interest because it can significantly enhance the network capacity by increasing the spatial reuse with macro and small cells. In the HetNet, we have several problems such as load imbalance and interference because of the difference in transmit power between macro and small cells and cell range expansion (CRE) can mitigate the problems. In this paper, we propose a new cell selection scheme with adaptive cell range expansion bias (CREB) for ultra dense HetNet and we analyze the performance of the proposed scheme in terms of average cell transmission rate through system-level simulations and compare it with those of other schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.63-66
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• 2015

As smart-phones become popular, mobile data traffic has been dramatically increasing and intensive researches on the next-generation mobile communication network is in progress to meet the increasing demand for mobile data traffic. In particular, heterogeneous network (HetNet) is attracting much interest because it can significantly enhance the network capacity by increasing the spatial resue with macro and small cells. In the HetNet, we have several problems such as load imbalance and interference because of the difference in transmit power between macro and small cells and cell range expansion (CRE) can mitigate the problems. In this paper, we propose a new cell selection scheme with adaptive cell range expansion bias (CREB) for ultra dense HetNet and we analyze the performance of the proposed scheme in terms of average cell transmission rate through system-level simulations and compare it with those of other schemes.

• Journal of KIISE:Software and Applications
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• v.35 no.8
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• pp.512-521
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• 2008

Web-based information services should be evaluated for accessibility and usability with various types of Internet Web-browsing devices, interacting with web information servers. A reliable ubiquitous Web information server, accessible and usable with a variety of Web-browsing devices (e.g. a full-browsing mobile phone), should be a unified center for personalized ubiquitous Web information services as well as for business models based on personalized advertisements. We studied an estimation of the accessibility and usability in Web interaction for personalized ubiquitous Web information services, as metrics for real-time estimation. We show empirical results based on implementation and experiments in Korea, Japan and China, using a test-bed Web site ('ktrip.net') and single-character Korean domain names (e.g. 김.net, 이.net, 박.net, 최.net, ㄱ.net, ㄴ.net ... ㅎ.net, ㅏ.net, ... ㅔ.net, ㄱ.com, ㄴ.com ... ㅎ.com).

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.9 no.4
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• pp.131-140
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• 2010

Recently, mobile wireless data traffic has been dramatically increased due to not only the popularization of digital convergence devices including smart phone, Net-book, and Tablet PC, but also the vitalization of wireless Internet related eco-systems such as AppStore. In addition, it is expected that a tremendous increase in mobile data is caused by the release of unlimited mobile data plans (flat-fee). In order to deal with such mobile data traffic explosion, it is necessary that network operators should make efforts to offload wireless data traffic. This paper reviews the condition of mobile wireless data traffic in domestic and international telecommunication industry and looks for various action plans to overcome the difficulty of network operators.