Browsing by Author "Kao, Yi-Chih"

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A Method of Driving Characteristics Recognition on Vehicle Operation Sequence
(2019-01-01)
Zhang, Yu
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Shen, Bo
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Kao, Yi-Chih
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Chou, Hsin-Hung
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資訊技術服務中心
Driving behavior has been proved to have a great influence on road safety. Recognizing driving characteristic is an essential part of reducing traffic fatalities and developing intelligent traffic system. In this paper, we propose a method of driving characteristics recognition through mining vehicle operation data such as GPS, velocity and direction collected by the On-Board Diagnostic (OBD) port of vehicles. Based on the feature extracted from the vehicle operation sequence, we employ K-means algorithm to cluster and recognize different driving characteristics after reasonable normalization and dimensionality reduction of the features. Analysis and experimental results indicate that the proposed method has good application significance on mining effective information in vehicle operation data sequence.
A New Method to Detect the Adversarial Attack Based on the Residual Image
(2019-01-01)
Sun, Feng
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Zhang, Zhenjiang
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Kao, Yi-Chih
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Li, Tianzhou
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Shen, Bo
Nowadays, with the development of artificial intelligence, deep learning has attracted more and more attention. Whereas deep neural network has made incredible progress in many domains including Computer Vision, Nature Language Processing, etc, recent studies show that they are vulnerable to the adversarial attacks which takes legitimate images with undetected perturbation as input and can mislead the model to predict incorrect outputs. We consider that the key point of the adversarial attack is the undetected perturbation added to the input. It will be of great significance to eliminate the effect of the added noise. Thus, we design a new, efficient model based on residual image which can detect this potential adversarial attack. We design a method to get the residual image which can capture these possible perturbations. Based on the residual image we got, the detection mechanism can help us detect whether it is an adversarial image or not. A serial of experiments has also been carried out. Subsequent experiments prove that the new detection method can detect the adversarial attack with high effectivity.
A Novel Method for Designing Information Technology Services
(2016-01-01)
Kao, Yi-Chih
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Chang, Yung-Chia
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Peng, Sheng-Lung
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Chang, Ruay-Shiung
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交大名義發表
Information technology (IT) services are diverse and complex. Numerous service design methods have been developed for designing and developing products. However, owing to the limited availability of useful tools in IT service design, these methods are ineffective. This study proposes an innovative three-dimensional method for designing IT services. The proposed method considers user requirements, an organization's business requirements, service providers' management requirements as well as the decision-making criteria of management representatives to ensure a smooth implementation of a designed IT service. Using this method, a prototype system to improve campus wireless local area network services was developed and tested at a university in Taiwan. The prototype system reduced the need for repetitive authentication and the time required to solve service problems and address user complaints. In addition, the service design team observed an approximately 70% reduction in project cycle time. The proposed method provided a systematic means to organize the design and implementation of IT services.
An Autoblocking Mechanism for Firewall Service
(2017-01-01)
Fu, Shan-Jung
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Hsu, Huai-Wen
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Kao, Yi-Chih
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Tsai, Shi-Chun
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Tseng, Chien-Chao
A distributed denial-of-service (DDoS) attack could cause the incoming connections per second exceeding the capacity of the firewall device and the network system might be paralyzed. By analyzing the syslog of firewall, we design an effective mechanism to block malicious source IPs automatically from the router. We have undergone a field trial on campus for two years. The collected data shows that our approach significantly reduces suspicious traffic and improve the stability of overall network service.
Balanced Service Chaining in Software-Defined Networks with Network Function Virtualization
(2016-11)
Lin, Po-Ching
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Lin, Ying-Dar
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Wu, Cheng-Ying
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Lai, Yuan-Cheng
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Kao, Yi-Chih
Balanced Hash Tree (BHT) is a mechanism for service function (SF) chaining, service routing, and traffic steering that enables switches to select SF instances for load balancing without involving the controller. In an experimental evaluation, BHT decreased packet-in message-processing time by 92.5 percent and achieved near-perfect load-balancing performance.
Deploying WLAN service with OpenFlow technology
(2017-05-01)
Hsu, Huai-Wen
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Huang, Kuei-Li
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Kao, Yi-Chih
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Tsai, Shi-Chun
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Lin, Yi-Bing
In this paper, we proposed a feasible software-defined networking (SDN) wireless local area network (WLAN) solution that leverages OpenFlow technique and provides affordable centralized WLAN service without the proprietary restrictions of centralized thin access point WLAN architecture. On the basis of an SDN-enabled WLAN architecture with fat access points, we implement and deploy a wireless network test bed, where network administrators can exploit the extensibility and flexibility of OpenFlow-based SDN switches and controller. Service providers can develop customized application modules and required features. We build our system with open sources and commercial off-the-shelf hardware and develop a mechanism to control wireless bandwidth. Field experimental results show that our SDN wireless bandwidth control application can effectively manage bandwidth in a dynamic and flexible way via the SDN WLAN.
Dual-Stack Network Management Through One-Time Authentication Mechanism
(2020-01-01)
Kao, Yi-Chih
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Liu, Jui-Chun
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Ke, Yi-Quan
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Tsai, Shi-Chun
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Lin, Yi-Bing
The exhaustion of IPv4 addresses has led to the rapid implementation of IPv6. However, the design of IPv6 is incompatible with that of its predecessor IPv4 and slows down the development of the IPv4-to-IPv6 migration. Several transitioning mechanisms have been proposed to attain the compatibility of IPv4 and IPv6 to bridge the gap between these two heterogeneous protocols. The two protocols would need to coexist continually before IPv6 completely takes over IPv4. However, the existing captive portal authentication systems generally do not support IPv4/IPv6 dual-stack authentication and lack one-time dual-stack authentication solutions. Upgrading the authentication system has become an urgent problem to be addressed. This study presents dual-stack network management strategies using a novel one-time authentication mechanism for large and complex dual-stack network environments. The proposed authentication system resolves the inconvenience of separate IPv4 and IPv6 authentication and effectively improves the compatibility of the two protocols. Furthermore, authenticating both IPv4 and IPv6 increases the traceability of traffic logs when security attacks occur. The proposed solution is deployed in a campus dormitory environment, and the feasibility and stability are successfully verified.
EZ-Net BYOD Service Management in Campus Wireless Networks
(2017-07-01)
Kao, Yi-Chih
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Chang, Yung-Chia
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Chang, Ruay-Shiung
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工業工程與管理學系
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資訊技術服務中心
We consider management issues associated with bring your own device (BYOD) services on a university campus. More than 70% of the users at the studied university access wireless networks at the campus through BYOD services. Thus, we propose the EZ-Net BYOD service management system, which implements a fail-through authentication function to an existing wireless local area network controller via multiple externally established authentication servers. The proposed system requires no client-side configuration and is not limited to any particular wireless network equipment. The proposed system was deployed and evaluated on campus. Results show that the EZ-Net system saves an average of 60 min of authentication time per month for each user. In addition, it offers a low-cost and efficient alternative to commercial BYOD service management software.
Managing Bring Your Own Device Services in Campus Wireless Networks
(2015)
Kao, Yi-Chih
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Chang, Yung-Chia
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Chang, Ruay-Shiung
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工業工程與管理學系
;
資訊技術服務中心
We consider the security issues associated with bring your own device (BYOD) services on campus. More than 70% of the cyber users at the studied university access wireless campus networks through BYOD. Although wireless access is convenient for users, its network management remains a problem. We analyze existing BYOD solutions that are applicable only to particular wireless network architectures, that require users to register their devices to a management platform, or that install client software. Moreover, commercial software is often prohibitively expensive for educational institutes. We found that most users enter their usernames and passwords multiple times a day, resulting in inconvenient user authentications. Thus, we propose an EZ-Net BYOD service management system that imposes a fail-through authentication function to an existing wireless local area network mobility controller via multiple externally established authentication servers. This solution requires no client-side configuration and is not limited to any particular brand of wireless network equipment. The solution is evaluated and deployed on campus. The proposed EZ-Net BYOD system saves an average of 60 min of authentication time per month for each user and allows the studied university to save tens of thousands of US dollars on licensing fees for BYOD service management software.
Scalable multicasting with multiple shared trees in software defined networking
(2017-01-15)
Lin, Ying-Dar
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Lai, Yuan-Cheng
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Teng, Hung-Yi
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Liao, Chun-Chieh
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Kao, Yi-Chih
With Software Defined Networking (SDN), IP multicast becomes promising again. For IPTV applications over SDN, existing works would not scale well since they are based on per-source trees. As control-plane in SDN is logically centralized, constructing multiple shared trees is more feasible than that in traditional IP networks. Thus, in this work, we present a locality-aware multicast approach (LAMA) to construct multi-group shared trees in SDN, where each shared tree covers multiple multicast groups. In LAMA, the controller first clusters the multicast sources located in the vicinity into the same multicast cluster. For each multicast cluster, the controller selects the center switch which has the minimum distance to all multicast sources as its rendezvous point (RP) and then constructs a shortest-path multicast tree from the RP to its hosts. Finally, based on the multi-group shared trees, the controller can establish coarse-grained flow entries into on-tree switches to reduce the number of installed flow entries. Emulations on the Ryu controller and the Mininet emulator show that only 2-5 shared trees would suffice. The computation time in the controller using LAMA is around 70 ms, much less than hundreds ms required for per-source trees. Moreover, LAMA only establishes 2300 flow entries, 4% of that with per-source trees in a large topology.