• International Journal of Control, Automation, and Systems
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• 제5권2호
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• pp.200-207
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• 2007

The passive direction finding cross localization method is widely adopted in passive tracking, therefore there will exist masses of false intersection points. Eliminating these false intersection points correctly and quickly is a key technique in passive localization. A new method is proposed for passive locating and tracking multi-jammer target in this paper. It not only solves the difficulty of determining the number of targets when masses of false intersection points existing, but also solves the initialization problem of elastic network. Thus this method solves the problem of multi-jammer target correlation and the elimination of static false intersection points. The method which dynamically establishes multiple hypothesis trajectory trees solves the problem of eliminating the remaining false intersection points. Simulation results show that computational burden of the method is lower, the elastic network can more quickly find all or most of the targets and have a more probability of locking the real targets. This method can eliminate more false intersection points.

• Journal of Information Display
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• 제2권2호
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• pp.32-38
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• 2001

PDP(plasma display panel) represents the gray levels by the pulse number modulation technique that results in undesirable dynamic false contours on moving images. This paper proposes a LUT(Look-up table) based error diffusion algorithm for reduction of the dynamic false contours. A quantitative measure of the dynamic false contours is defined first. The measure of the dynamic false contours is calculated through simulation of every gray level combination of two consecutive frames. Based on the calculated measures, a modified gray level for a pair of gray levels of two consecutive frames is chosen to reduce the dynamic false contours. The chosen gray levels serve as contents of a gray level conversion LUT. Given a pair of gray levels of two consecutive frames, the gray level of current frame is modified based on the gray level conversion LUT. The new gray level is displayed on PDP. An error diffusion algorithm is, then, applied to compensate for the differences in the gray levels.

• 복식문화연구
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• 제4권1호
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• pp.15-28
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• 1996

This study is concerned with the prohibition of False Hair(加笙) and a primary factor in Lee Dynasty. Assuming that the trend of simplification in false hair is closely related to the idea of practical science to be the social and ideal background of those times, we researched. The results are as follows: Constant discussions and prohibitions against false hair were designed to differentiate between classes but to discard a variety. Goge(高笙) came to be a big problem during the reign of king Sung-Jong(成宗) and after on arguemt for the usage of false hair was in vogue king Young-Jo(英祖) and Jung-Jo(正祖). Finally, the wearing of Hooge(後笙) came to be a national regulation in manners and customs, and also brought the realization of prohibition against the usage of false hair. It is believed that the performance and the effect of the prohibition against the usage of false hair have a close relation with the idea of practical science.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2008년도 정보통신설비 학술대회
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• pp.159-162
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• 2008

Generally, sensor nodes can be easily compromised and seized by an adversary because sensor nodes are hostile environments after dissemination. An adversary may be various security attacks into the networks using compromised node. False data injection attack using compromised node, it may not only cause false alarms, but also the depletion of the severe amount of energy waste. Dynamic en-route scheme for Filtering False Data Injection (DEF) can detect and drop such forged report during the forwarding process. In this scheme, each forwarding nodes verify reports using a regular probability. In this paper, we propose verification probability adjustment scheme of forwarding nodes though a fuzzy rule-base system for the Dynamic en-route filtering scheme for Filtering False Data Injection in sensor networks. Verification probability determination of forwarding nodes use false traffic rate and distance form source to base station.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2004년도 가을 학술발표논문집 Vol.31 No.2 (1)
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• pp.307-309
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• 2004

침입탐지시스템에서 발생되는 오 경보는 false positive 와 false negative 로 구분된다. false positive는 실제적인 공격은 아니지만 공격이라고 오인하여 경보를 발생시켜 시스템의 효율성을 떨어뜨리기 때문에 false positive 패턴에 대한 분석이 필요하다. 오 경보 데이터는 시간이 지남에 따라 데이터의 양뿐만 아니라 데이터 패턴의 특성 또한 변하게 된다 따라서 새로운 데이터가 추가될 때마다 오 경보 데이터의 패턴을 분석할 수 있는 도구가 필요하다. 이 논문에서는 오 경보 데이터로부터 false positive 의 패턴을 분석할 수 있는 프레임워크에 대해서 기술한다. 우리의 프레임워크는 시간이 지남에 따라 변하는 데이터의 패턴 특성을 분석할 수 있도록 하기 위해 점진적 연관규칙 기법을 적용한다. 이 프레임워크를 통해서 false positive 패턴 특성의 변화를 효율적으로 관리 할 수 있다.

• 한국시뮬레이션학회논문지
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• 제19권4호
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• pp.139-149
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• 2010

인터넷은 확장성과 최선형 라우팅 서비스를 목적으로 설계되었기 때문에 보안상에 취약점을 가진다. 이에 IP spoofing과 DoS/DDoS 공격을 탐지하기 위한 다양한 공격 탐지 방법들이 제안되었다. DoS/DDoS 공격은 공격이 시작되고 짧은 시간 내에 목적을 이루기 때문에 공격 탐지 알고리즘들은 빠른 시간 내에 정확한 탐지를 하는 것이 중요하다. 공격 탐지 알고리즘들은 미탐지율과 오탐지율로 이루어진 오경고율을 가지며 공격 탐지 알고리즘의 성능을 평가하는 중요한 요소가 된다. 본 논문에서는 공격 탐지 알고리즘의 특징을 살펴보고 그 성능을 분석하였다. 공격 탐지 알고리즘의 성능은 미탐지율과 오탐지율을 변화시켰을 시, 공격 트래픽 및 일반 트래픽에 미치는 영향을 시뮬레이션을 통해 각각 분석하였다. 이를 통해 전송되는 공격 패킷의 수는 미탐지율에 비례하며, 전송되는 일반 패킷의 수는 일정 치 이하의 미탐지율과 오탐지율에 반비례하는 것을 확인하였다. 또 공격 탐지 알고리즘의 미탐지율 변화에 따른 오탐지율의 변화를 분석하여 미탐지율과 오탐지율의 관계를 도출하고 공격탐지 알고리즘의 한계를 분석하였다. 이러한 한계를 극복하기 위해 정확한 네트워크 상태를 판단하여 공격 탐지 알고리즘의 한계를 줄이고 성능을 개선하는 방안을 제안하였고 그 결과, 공격 탐지 알고리즘의 성능이 보다 향상됨을 확인하였다.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권1호
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• pp.111-115
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• 2008

버퍼오버런 분석기가 루프안에서 발생시키는 허위경보를 간편하고도 효율적으로 줄이는 방법과 경험을 소개한다. 버퍼오버런 분석기는 루프와 배열을 많이 사용하는 프로그램을 분석할 때 많은 허위경보를 발생시킨다. 우리는 먼저 루프를 많이 사용하는 프로그램인 임베디드 프로그램과 암호화 관련 프로그램들에서 발생하는 허위경보를 조사하여 허위경보를 일으키는 루프의 패턴을 조사했다. 그 다음에 그 루프에 특화된 간단하고 효율적인 재분석기를 고안하였다. 우리가 제안하는 재분석기는 분석기가 분석을 끝낸 후 내 놓는 분석결과를 보고 재분석할 목표가 되는 루프만을 찾아서 초벌분석보다 더 정교한 분석을 하여 허위경보를 안전하게 제거한다. 버퍼오버런 분석기인 아이락에 구현하여 실험해본 결과 전체 루프 관련 허위경보 중 32% 가량이 제거되었다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제27권6호
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• pp.551-555
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• 2001

False aneurysms(Pseudoaneurysms) and arteriovenous fistulas have only rarely been reported in the facial region. In this region the false aneurysm arises most frequently in the superficial temporal and facial artery, but other branches of the external carotid are sometimes involved, including the maxillary and lingual artery. False aneurysms can be occurred by blunt trauma that either laceration or rupture the full thickness of the arterial wall. The diagnosis of a false arterial aneurysm can be often made solely on the basis of physical examination. Angiography is helpful for conformation, for delineating the lesion and its vascular supply, and for ruling out the presence of associated vascular lesions such as arteriovenous fistulas. Ultrasonography may also be useful in delineating lesions that are not easily accessible for physical examination. Treatment of false aneurysms is excision, ligation, and arterial embolization. This is a case of false aneurysm of the lingual artery after facial trauma caused by traffic accident. The lesion was successfully treated by embolization and ligation of the lingual and facial branches of the external carotid artery.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제8권4호
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• pp.316-321
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• 2008

Advanced computer network technology enables computers to be connected in an open network environment. Despite the growing numbers of security threats to networks, most intrusion detection identifies security attacks mainly by detecting misuse using a set of rules based on past hacking patterns. This pattern matching has a high rate of false positives and can not detect new hacking patterns, which makes it vulnerable to previously unidentified attack patterns and variations in attack and increases false negatives. Intrusion detection and analysis technologies are thus required. This paper investigates the asymmetric costs of false errors to enhance the performances the detection systems. The proposed method utilizes the network model to consider the cost ratio of false errors. By comparing false positive errors with false negative errors, this scheme achieved better performance on the view point of both security and system performance objectives. The results of our empirical experiment show that the network model provides high accuracy in detection. In addition, the simulation results show that effectiveness of anomaly traffic detection is enhanced by considering the costs of false errors.

• IEIE Transactions on Smart Processing and Computing
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• 제4권3호
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• pp.163-168
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• 2015

Many IP address lookup approaches employ Bloom filters to obtain a high-speed search performance. Especially, it has been recently studied that the search performance of trie-based algorithms can be significantly improved by adding Bloom filters. In such algorithms, the number of trie accesses can be greatly reduced because Bloom filters can determine whether a node exists in a trie without actually accessing the trie. Bloom filters do not have false negatives but have false positives. False positives can lead to unnecessary trie accesses. The false positive rate must thus be reduced to enhance the performance of lookup algorithms applying Bloom filters. One important characteristic of trie-based algorithms is that all the ancestors of a node are also stored. The proposed algorithm utilizes this characteristic in reducing the false positive rate of a Bloom filter without increasing the size of the memory for the Bloom filter. When a Bloom filter produces a positive result for a node of a trie, we propose to check whether the ancestors of the node are also positives. Because Bloom filters have no false negatives, the negatives of any of the ancestors mean that the positive of the node is false. In other words, we propose to use more Bloom filter queries to reduce the false positive rate of a Bloom filter in trie-based algorithms. Simulation results show that querying one ancestor of a node can reduce the false positive rate by up to 67% with exactly the same architecture and the same memory requirement. The proposed approach can be applied to other trie-based algorithms employing Bloom filters.