• Journal of Digital Convergence
• /
• v.13 no.5
• /
• pp.251-257
• /
• 2015

Intrusion protection system is a security system that stop abnormal traffics through automatic activity by finding out attack signatures in network. Unlike firewall or intrusion detection system that defends passively, it is a solution that stop the intrusion before intrusion warning. The security performance of intrusion protection system is influenced by security auditability, user data protection, security athentication, etc., and performance is influenced by detection time, throughput, attack prevention performance, etc. In this paper, we constructed a convergence performance evaluation model about software product evaluation to construct the model for security performance evaluation of intrusion protection system based on CC(Common Criteria : ISO/IEC 15408) and ISO international standard about software product evaluation.

• TTA Journal
• /
• s.171
• /
• pp.42-45
• /
• 2017

• TTA Journal
• /
• s.164
• /
• pp.45-49
• /
• 2016

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.37 no.1B
• /
• pp.59-66
• /
• 2012

The use of MPSoC has been increasing because of a rise of use of mobile devices and complex applications. For improving the performance of MPSoC, number of processor has been increasing. Standard MPI is used for efficiently sending data in distributed memory architecture that has advantage in multi processor. Standard In this paper, we propose a scalable distributed memory system with a low cost hardware message passing interface(MPI). The proposed architecture improves transfer rate with buffered send for small size packet. Three queues, Ready Queue, Request Queue, and Reservation Queue, work as previous architecture, and two queues, Small Ready Queue and Small Request Queue, are added to send small size packet. When the critical point is set 8 bytes, the proposed architecture takes more than 2 times the performance improvement in the data that below the critical point.

• The KIPS Transactions:PartC
• /
• v.16C no.3
• /
• pp.393-406
• /
• 2009

This paper introduces two functions added to the current version of ns-2 simulator for better accuracy of IEEE 802.15.4 network simulations. The first one is to automatically place hidden nodes over the ring topology in which the coordinator is centered, when the number of hidden nodes and total number of nodes is given. Collisions of signals can be distinguished into the trace file according to the ways of participation of hidden nodes. The second one is the CCA deferment algorithm described in IEEE 802.15.4-2006 standard which is not implemented in the current version of ns-2. Owing to these additional functions, we can carry out the precise analysis of the performance effects of hidden nodes and CCA deferment algorithm on 802.15.4 networks. Simulation results present at least 66% of performance degradation in throughput and drastic increase of collision probability up to 90% from 65% by just a single hidden node. Besides, 2006 standard for CCA deferment algorithm gives 19% lower collision probability and 38% higher performance.

• Journal of the KSME
• /
• v.25 no.1
• /
• pp.9-22
• /
• 1985

재래의 표준기어방식으로는 여러 가지의 취약점이 있는데, 이러한 결점은 치형을 다시 교 정(correction)하는 전위기어방식으로 설계하여 성능이 개선되고 해결될 수 있다. Corrected tooth의 창성은 공구를 전위하여 절삭하므로 이루어지고, 이 방식은 치형곡선의 곡률반지름을 증가시키며, 미끄럼률을 감소시켜서 강도를 증가시키도록 설계할 수 있다. 본 해설에서는 전위 기어 영역에서 기어의 성능개선과 복잡한 강도의 설계방법등을 최근경향에 부합시키고 통일된 형식의 체계로 기어설계를 쉽게 발전시킬 수 있도록 시도한 것이다.

• TTA Journal
• /
• s.73
• /
• pp.146-151
• /
• 2001

본 고에서는 인터넷 통신서비스의 기반을 제공하고 있는 IP 기반 통신망(IP based network)의 망 성능(Network Performance)에 관련된 기본 개요 및 관련 국제표준기구의 표준화 동향을 파악하고, ITU-T SG13(국제전기통신연합 제13연구반)의 Q.6에서 수행하고 있는 IP 망 성능 관련 권고안들(2001년내 권고안 승인예정)의 동향을 살펴보고자 한다.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.44 no.6
• /
• pp.51-61
• /
• 2007

In this paper, Air-interface protocols of ISO 18000-6 Types and EPCglobal Classes applied to RFID system in UHF band are analyzed, and those anticollision algorithms are realized. Also, the each algorithm which improves the performance of standard protocol is proposed, and the performance is compared when clock period of link timing is a identical condition on $12.5{\mu}s$. As the result, when 500 tags exist simultaneously inside reader interrogation zone, the tag recognition performance of a standard protocol is better in preceding order of Class-1 Generation-1, Type B, Type A, Class-0 and Class-1 Generation-2. And also the performance of improved protocol is better in ascending order of Type B, Type A, Class-1 Generation-1, Class-0 and Class-1 Generation-2. Therefore, performance of tag recognition remarkably depends on the regulated clock period in the protocol and link timing between a reader and a tag.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.33 no.7B
• /
• pp.518-527
• /
• 2008

Tag collection is one of the major functions in Radio Frequency Identification (RFID) systems. IS0/IEC 18000-7 defines the tag collection algorithm using the anti-collision algorithm, based on the framed slotted ALOHA for active RFID systems. However, it has inefficiency problems that reduce tag collection performance by deciding non-optimum slot size or using point-to-point commands to put collected tags to sleep. In this paper, we propose two mechanisms to overcome the inefficiency problems and improve tag collection performance: 1) a new slot size decision mechanism to allow the reader to choose the optimum slot size flexibly and 2) a broadcast-based sleep mechanism to put collected tags to sleep effectively. We also implemented an active RFID system, composed of an active RFID reader and multiple tags, and the reader is designed to maximize tag collection performance when the proposed mechanisms are applied. In experiments, we evaluated the tag collection performance using one reader and 50 tags in the real-world environment. The experimental results show that when two mechanisms are applied and the initial number of slots is chosen appropriately, the performance of the proposed tag collection algorithm is greatly enhanced, compared with that of the standard.

• Journal of Digital Contents Society
• /
• v.8 no.4
• /
• pp.491-497
• /
• 2007

RPersonal area networking technology is becoming increasingly important in enabling useful wireless home applications. For example, Bluetooth and IEEE 802.11b standards are the most commonly deployed technologies for wireless home applications. However, because both standards share the same unlicensed ISM (Industrial, Scientific, Medical) radio spectrum, severe interference is inevitable and performance can be impaired significantly when heterogeneous devices using the two technologies come into close proximity. In this paper, we research Gaussian FSK Bluetooth system, which is an open specification technology for short-range wireless connectivity between electronic devices. In this paper, we analyzes the effects of co-channel interference on the performance of a Gaussian FSK Bluetooth system. Performance criteria used in the study are the signal to interference power ratio (SIR), interference index, and the bit error rate (BER) in the wireless channel. The effect of co-channel interference from various sources on the performance of a Gaussian FSK Bluetooth system is analyzed using an IGA(Impulsive Gaussian Approximation) method, and these quantities are plotted against Eb/No, $\rho$ and SIR for various channel conditions in figures.