• Title/Summary/Keyword: 3AP

Search Result 1,489, Processing Time 0.033 seconds

A Rogue AP Detection Method Based on DHCP Snooping (DHCP 스누핑 기반의 비인가 AP 탐지 기법)

  • Park, Seungchul
    • Journal of Internet Computing and Services
    • /
    • v.17 no.3
    • /
    • pp.11-18
    • /
    • 2016
  • Accessing unauthorized rogue APs in WiFi environments is a very dangerous behavior which may lead WiFi users to be exposed to the various cyber attacks such as sniffing, phishing, and pharming attacks. Therefore, prompt and precise detection of rogue APs and properly alarming to the corresponding users has become one of most essential requirements for the WiFi security. This paper proposes a new rogue AP detection method which is mainly using the installation information of authorized APs and the DHCP snooping information of the corresponding switches. The proposed method detects rogue APs promptly and precisely, and notify in realtime to the corresponding users. Since the proposed method is simple and does not require any special devices, it is very cost-effective comparing to the wireless intrusion prevention systems which are normally based on a number of detection sensors and servers. And it is highly precise and prompt in rogue AP detection and flexible in deployment comparing to the existing rogue AP detection methods based on the timing information, location information, and white list information.

A Study of Call Admission Scheme using Power Strength Threshold value between APs in Wireless LAN Environments (무선랜 환경에서 AP간 전력임계치값을 통한 호 처리 연구)

  • Lim, Seung-Cheol
    • The Journal of the Institute of Internet, Broadcasting and Communication
    • /
    • v.15 no.3
    • /
    • pp.107-112
    • /
    • 2015
  • A smart phone and the number of wireless terminals are mobile-to the nature of the AP mobility are many call transfer between wireless terminals and AP (Access Point). Each wireless terminal that is the call processing process for each is relatively large to cause the wireless traffic, and a factor that inhibits the efficient use of the radio band on the AP. In this paper, we use the power intensity threshold and threshold timer of the AP received by the mobile station to reduce the amount of switching traffic between the AP's cause and traffic generation factors between the wireless device and the AP that can effectively utilize the radio traffic from the AP the measures proposed. The proposed method and the conventional method is improved by simulation to handle the amount of radio traffic from the AP it was confirmed that it is possible to effectively utilize the whole of the radio band.

Analysis of Time-Based Unauthorized AP Detection Methods According to Hardware Performance of Unauthorized AP (비인증 AP의 하드웨어 성능에 따른 시간 측정 기반의 비인증 AP 탐색 기법의 분석)

  • Jang, Rhong-Ho;Kang, Jeon-Il;Nyang, Dae-Hun;Lee, Kyung-Hee
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.40 no.3
    • /
    • pp.551-558
    • /
    • 2015
  • As more people use Wi-Fi and hotspot, unauthorized APs become one of big security problems in modern society. From the beginning of 2010, researchers study about unauthorized AP continually and contributed a lot of methods of detecting unauthorized AP that use wireless resources. Many researches about unauthorized AP detection use time-delay measurement (e.g., average or standard deviation) which is caused by additional wireless connection. In the most previous researches, however, the unauthorized APs consist of laptop and pulg-in Wi-Fi adaptor, and researchers did not concern about time-delay caused by software network sharing. In this paper, we show that existing unauthorized AP detection scheme that can not efficiently classify the high performance unauthorized AP.

EXAMPLES AND FUNCTION THEOREMS AROUND AP AND WAP SPACES

  • Cho, Myung-Hyun;Kim, Jun-Hui;Moon, Mi-Ae
    • Communications of the Korean Mathematical Society
    • /
    • v.23 no.3
    • /
    • pp.447-452
    • /
    • 2008
  • We provide some examples around AP and WAP spaces which are connected with higher convergence properties-radiality, semiradiality and pseudoradiality. We also prove a theorem (Theorem 3.2) that (a) any pseudo-open continuous image of an AP-space is an AP-space and (b) any pseudo-open continuous image of an WAP-space is an WAP-space. This answers the question posed by V. V. Tkachuk and I. V. Yaschenko [10].

Quality Characteristics of Calcium Acetate Prepared with Vinegars and Ash of Black Snail (식초와 다슬기회분을 이용하여 제조한 초산칼슘의 품질 특성)

  • 이명예;이예경;김순동
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.33 no.3
    • /
    • pp.593-597
    • /
    • 2004
  • This study was conducted to investigate the quality characteristics of liquid calcium acetate (LCAs) and solid calcium acetate (SCAs), Br-LCA, Pe-LCA and Ap-LCA as liquid form, Br-SCA, Pe-SCA and Ap-SCA as solid form. Calcium acetate was prepared by reacting of vinegars [brown rice (Br), persimmons (Pe) and apple (Ap)] and ash of black snail in order to obtain natural water soluble calcium resources. The pHs of the vinegars for preparing calcium acetate (CA) were the range of 2.34 ∼ 3.06, and the contents of the ash of black snail which reacted to 100 mL of the vinegars were 20.43∼23.50 g. The yields of solid CAs from 100 mL of the vinegars were 11.02∼13.01 g. The colors of liquid and solid CAs were light yellow in Ap-LCA and Ap-SCA, brown in Br-LCA and Br-SCA, dark brown in Pe-LCA and Pe-SCA. Calcium contents of Br-LCA, Pe-LCA and Ap-LCA were 3.02, 2.06 and 2.30% (w/v), and those of Br-SCA, Pe-SCA and Ap-SCA were 27.15, 16.31 and 19.48% (w/w), respectively. The solubilities of the solid CAs were 36.82 ∼ 39.92% (w/v) in distilled water, 32.05 ∼ 39.04% (w/v) in Soju, 13.12 ∼ 18.65% (w/v) in thick soysauce, 38.35 ∼ 38.90% (w/v) in ionic beverage, 33.47 ∼ 35.58% (w/v) in yoghurt, while the solid CAs formed the curds in soymilk and milk. The sour and bitter taste of the CAs were lower, while the astringent taste, fishy flavor and savory taste were higher than those of standard CA.

Preparation of Cr2O3/AP Composites and their Thermal Decomposition Characteristics (Cr2O3/AP 복합체 제조 및 그 열분해 특성)

  • Jung, Jae-Yun;Kim, Jae-Kyeong;Shim, Hong-Min;Kim, Hyoun-Soo;Koo, Kee-Kahb
    • Applied Chemistry for Engineering
    • /
    • v.26 no.2
    • /
    • pp.145-153
    • /
    • 2015
  • $Cr_2O_3/AP$ (ammonium perchlorate) energetic composites were prepared by a method of solvent/anti-solvent. XRD analysis revealed that the crystalline structure of AP in $Cr_2O_3/AP$ composites is the same as that of pure AP. SEM photomicrograph shows that an average size of cuboid $Cr_2O_3/AP$ composites is approximately $2.5{\mu}m$. TGA analysis shows that the addition of submicron $Cr_2O_3$ particles into AP lowers the HTD (high-temperature decomposition) compared to that of neat AP and the activation energy of the $Cr_2O_3/AP$ composites was calculated by the isoconversional Starlink method. Considering changes in the activation energy, the decomposition reaction mechanism of AP was suggested as follows; the decomposition with the formation of nucleation sites renders formation of porous structure in the composites up to conversion of about 0.25 and after further conversion of over 0.3, it seems that decomposition reaction vigorously takes place rather than sublimation of AP.

The Heterochromatin-1 Phosphorylation Contributes to TPA-Induced AP-1 Expression

  • Choi, Won Jun
    • Biomolecules & Therapeutics
    • /
    • v.22 no.4
    • /
    • pp.308-313
    • /
    • 2014
  • Activator protein-1 (AP-1) is an inducible transcription factor that contributes to the generation of chronic inflammation in response to oxidative and electrophilic stress. Previous studies have demonstrated that the PI3K/Akt1 pathway plays an important role in the transcriptional regulation of AP-1 expression. Although the histone post-translational modifications (PTMs) are assumed to affect the AP-1 transcriptional regulation by the PI3K/Akt pathway, the detailed mechanisms are completely unknown. In the present study, we show that heterochromatin 1 gamma ($HP1{\gamma}$) plays a negative role in TPA-induced c-Jun and c-Fos expression. We show that TPA-induced Akt1 directly phosphorylates $HP1{\gamma}$, abrogates its suppressive function and increases the interaction between histone H3 and 14-3-$3{\varepsilon}$. Collectively, these our data illustrate that the activation of PI3K/Akt pathway may play a permissive role in the recruitment of histone readers or other coactivators on the chromatin, thereby affecting the degree of AP-1 transcription.

Development of Test Cases of STEP AP216 for the Exchange of Hullform Data (선형정보 교환을 위한 STEP AP216 Test Case 개발)

  • 이순섭;김용대;서정우;김수영
    • Korean Journal of Computational Design and Engineering
    • /
    • v.8 no.3
    • /
    • pp.141-149
    • /
    • 2003
  • The ship STEP is an international standard for the computer-interpretable representation of ship product information and for the exchange of ship product model data. The ship STEP consists of several APs(Application Protocol), such as AP215(ship arrangement), AP216(ship moulded form), AP218(ship structures), AP226(ship mechanical systems), and AP234(operating logs, records, message). The STEP AP216(ISO 10303) are an application protocol for the exchange of ship arrangement and ship moulded forms. The AP216 specifies the geometric shape and the hydrostatic properties of the ship moulded form. This paper introduces the state-of-the-art of ship STEP AP216 and develops the test case for the validation of data structure of AP216.

Functional Characterization of the ${\alpha}$- and ${\beta}$-Subunits of a Group II Chaperonin from Aeropyrum pernix K1

  • Lee, Jin-Woo;Kim, Se Won;Kim, Jeong-Hwan;Jeon, Sung-Jong;Kwon, Hyun-Ju;Kim, Byung-Woo;Nam, Soo-Wan
    • Journal of Microbiology and Biotechnology
    • /
    • v.23 no.6
    • /
    • pp.818-825
    • /
    • 2013
  • We isolated and functionally characterized the ${\alpha}$- and ${\beta}$-subunits (ApCpnA and ApCpnB) of a chaperonin from Aeropyrum pernix K1. The constructed vectors pET3d-ApCpnA and pET21a-ApCpnB were transformed into E. coli Rosetta (DE3), BL21 (DE3), or CodonPlus (DE3) cells. The expression of ApCpnA (60.7 kDa) and ApCpnB (61.2 kDa) was confirmed by SDS-PAGE analysis. Recombinant ApCpnA and ApCpnB were purified by heat-shock treatment and anion-exchange chromatography. ApCpnA and ApCpnB were able to hydrolyze not only ATP, but also CTP, GTP, and UTP, albeit with different efficacies. Purified ApCpnA and ApCpnB showed the highest ATPase, CTPase, UTPase, and GTPase activities at $80^{\circ}C$. Furthermore, the addition of ApCpnA and ApCpnB effectively protected citrate synthase (CS) and alcohol dehydrogenase (ADH) from thermal aggregation and inactivation at $43^{\circ}C$ and $50^{\circ}C$, respectively. In particular, the addition of ATP or CTP to ApCpnA and ApCpnB resulted in the most effective prevention of thermal aggregation and inactivation of CS and ADH. The ATPase activity of the two chaperonin subunits was dependent on the salt concentration. Among the ions we examined, potassium ions were the most effective at enhancing the ATP hydrolysis activity of ApCpnA and ApCpnB.