• Title/Summary/Keyword: Reverse Analysis

Search Result 2,098, Processing Time 0.027 seconds

Icefex: Protocol Format Extraction from IL-based Concolic Execution

  • Pan, Fan;Wu, Li-Fa;Hong, Zheng;Li, Hua-Bo;Lai, Hai-Guang;Zheng, Chen-Hui
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • v.7 no.3
    • /
    • pp.576-599
    • /
    • 2013
  • Protocol reverse engineering is useful for many security applications, including intelligent fuzzing, intrusion detection and fingerprint generation. Since manual reverse engineering is a time-consuming and tedious process, a number of automatic techniques have been proposed. However, the accuracy of these techniques is limited due to the complexity of binary instructions, and the derived formats have missed constraints that are critical for security applications. In this paper, we propose a new approach for protocol format extraction. Our approach reasons about only the evaluation behavior of a program on the input message from concolic execution, and enables field identification and constraint inference with high accuracy. Moreover, it performs binary analysis with low complexity by reducing modern instruction sets to BIL, a small, well-specified and architecture-independent language. We have implemented our approach into a system called Icefex and evaluated it over real-world implementations of DNS, eDonkey, FTP, HTTP and McAfee ePO protocols. Experimental results show that our approach is more accurate and effective at extracting protocol formats than other approaches.

Synthesis and Characterization of ZnAl2O4 Nanopowders by a Reverse Micelle Processing

  • Hoon, Son-Jung;Sohn, Jeongho;Shin, Hyung-Sup;Bae, Dong-Sik
    • Korean Journal of Materials Research
    • /
    • v.25 no.11
    • /
    • pp.598-601
    • /
    • 2015
  • Using reverse micelle processing, $ZnAl_2O_4$ nanopowders were synthesized from a mixed precursor(consisting of $Zn(NO_3)_2$ and $Al(NO_3)_3$). The $ZnAl_2O_4$ was prepared by mixing the aqueous solution at a molar ratio of Zn : Al = 1 : 2. The average size and distribution of the synthesized powders with heat treatment at $600^{\circ}C$ for 2 h were in the range of 10-20 nm and narrow, respectively. The average size of the synthesized powders increased with increasing water to surfactant molar ratio. The XRD diffraction patterns show that the phase of $ZnAl_2O_4$ was spinel(JCPDS No. 05-0669). The synthesized and calcined powders were characterized using a thermogravimetric - differential scanning calorimeter(TG-DSC), X-ray diffraction analysis (XRD), and high resolution transmission electron microscopy(HRTEM). The effects of the synthesis parameter, such as the molar ratio of water to surfactant, are discussed.

A FINITE ELEMENT ANALYSIS ON THE EFFECT OF THE REVERSE HEADGEAR TO THE MAXILLARY COMPLEX (REVERSE HEADGEAR가 상악골체에 미치는 영향에 관한 유한요소법적 분석)

  • Kim, Joo-Young;Sohn, Byung-Hwa
    • The korean journal of orthodontics
    • /
    • v.15 no.1
    • /
    • pp.7-22
    • /
    • 1985
  • The purpose of this study was to analyze the stress distribution and the displacement in the maxillary complex after the application of the reverse headgear. The direction of force was parallel to the occlusal plane. Orthopedic force,300gm, was applied to the maxilla of the dry human skull in a forward direction. The stress distribution and the displacement within the maxillary Complex was analyzed by a 3-dimensional finite element method. The results were as follows: 1. The stress distribution at the molar region was greater than that at the anterior. 2. The stress distribution at the lateral side of the premaxilla was greater than that at the middle aide, especially high stress was noted at the canine eminence. 9. Compressive stress was noted only at the frontozygomatic suture of the zygomatic arch. 4. A forward, upward, and sideward displacement was noted at the entire nodal points of the zygomaticomaxillary suture portion. A displacement with a slight rotation was observed on the transverse palatine suture. 5. The maximum stress was observed at the lateral side of the maxillary tuberosity area, and generally the forward and downward displacement was noted at all this area.

  • PDF

A Study on the Moment Gradient factor of Mono-symmetric I Beam (일축 대칭 I 형 보의 모멘트 구배계수에 대한 연구)

  • 김윤종;임남형;박남회;강영종
    • Proceedings of the KSR Conference
    • /
    • 2000.05a
    • /
    • pp.439-446
    • /
    • 2000
  • In this study, 7 dof (Including warping) beam element was developed to estimate the effects of wagner effects and load height effects on the lateral buckling strength of mono-symmetric I beam. Finite element buckling analysis of mono-symmetric I-shaped girders subjected to transverse loading applied at different heights on the cross-section were conducted. Linear moment gradient were considered, too. In these cases, girders are subjected to both single-curvature and Reverse-curvature bending. An applicability of current LRFD C$\sub$b/ on the mono-symmetric I beam was studied from the finite element results. The problems of current LRFD C$\sub$b/ occurring from load height effects and reverse curvature bending in unbraced length when applied on the mono-symmetric I beam were studied. Solutions to these problems are also presented.

  • PDF

The Study on Static Alignment Classification based on the Full Spine AP X-ray of Adults aged 30-39 (30대 성인의 골반, 척추 및 견갑대 정렬의 패턴 분석 - Full Spine AP X-ray 분석에 따른 -)

  • Park, Ji-Hyun;Hong, Seo-Young
    • Journal of Korean Medicine Rehabilitation
    • /
    • v.20 no.2
    • /
    • pp.89-99
    • /
    • 2010
  • Objectives : This study was designed to analyze the pattern of asymmetrical alignment. Methods : This study was carried out with the data from comprehensive medical testing. 91 subjects aged 30-39 were evaluated by full spine AP X-ray. For pelvis, innominate measurement(IM), off centering measurement(OCM), ilium shadow measurement(ISM), major axis of obturator foramen(MaF), minor axis of obturator foramen(MiF) were analyzed. Spinal curvature and height of shoulder girdle were analyzed. Results : 1. In pelvis, It. posterior-inferior and it. inflare combination pattern was 38 cases(42.8%). 2. In spinal curvature, "reverse S" curve was 45 cases(49.4%) and "reverse C" curve was 30 cases(33%). 3. In shoulder girdle, It. superior pattern was 42 cases(46.1 %) and It. superior pattern was 39 cases(42.9%). 4. In whole body analysis, It. posterior-inferior and It. inflare pelvis, "reverse S" spinal curvature and It. superior shoulder girdle combination patten was 11 cases(12.1 %). This pattern is similar to Kendall's right handedness pattern and Zink's common compensatory pattern. Conclusions : Results from this investigation showed asymmetrical alignment in 30-39 years-old adults. This results are expected to contribute to classifying the alignment pattern in clinic and systemic treatment.

Analysis of the ESD-Induced Degradation Behavior of Oxide VCSELs Using an Equivalent Circuit Model (ESD에 따른 산화형 VCSEL 열화 과정의 등가회로 모델을 이용한 분석)

  • Kim, Tae-Yong;Kim, Sang-Bae
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.45 no.3
    • /
    • pp.6-21
    • /
    • 2008
  • We have investigated the effect of the forward and reverse ESD pulse accumulation on the development of the oxide VCSEL's electrical and optical characteristics. The forward ESD-induced degradation is complicated, showing three degradation phases with increasing ESD voltage while the reverse ESD-induced degradation is divided by a sudden distinctive change in elecorl-optical characteristics. By comparing the measured L-I-V characteristics and their derivatives with the fitted characteristics using an equivalent circuit model as well as the large signal circuit model, the development of the oxide VCSEL's electro-optical characteristics under forward and reverse ESD conditions has been fully understood.

Reverse-Phase High Performance Liquid Chromatographic Determination of Amino Acids after Precolumn Derivatization with 1-Dimethyl-aminonaphthalene-5-sulfonyl chloride (Dansyl 유도체화와 역상 고성능액체크로마토그래피에 의한 아미노산의 정량)

  • 나혜경;전덕영;홍윤호
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.22 no.6
    • /
    • pp.815-822
    • /
    • 1993
  • This experiment was carried out to determine the separation condition of 1-dimethylaminonaphthalene-5-sulfony(Dansyl) derivatives of amino acids by reverse-phase high performance liquid chromatography with Nova-Pak C18 column. Determined solvent system was solvent A(200mA phosphate buffer pH 6.8 15%, acetonitrile 11%, water 74%) and solvent B(acetonitrile 65%, methanol 28%, water 7%). Linear gradient of solvent B was applied from 12% to 80% for 50min. Complete separation of 20 amino acids including asparagine and glutamine which constitute protein was achieved within 50min. As the detection limit was the range of picomole, the resolution power was excellent. Reproducibility of the retention time was less than mean $\pm$0.05min. According to the above optimum chromatographic conditions, the amino acid composition of some food and human blood was examined. The most affluent amino acid was alanine in human blood, aspartic acid and glutamic acid in soy sauce, alanine and threonine in soy milk and proline in milk and yoghurt.

  • PDF

Lack of Mutagenicity Potential of Periploca sepium Bge. in Bacterial Reverse Mutation (Ames) Test, Chromosomal Aberration and Micronucleus Test in Mice

  • Zhang, Mei-Shu;Bang, In-Seok;Park, Cheol-Beom
    • Environmental Analysis Health and Toxicology
    • /
    • v.27
    • /
    • pp.14.1-14.6
    • /
    • 2012
  • Objectives: The root barks of Periploca sepium Bge. (P. sepium) has been used in traditional Chinese medicine for healing wounds and treating rheumatoid arthritis. However, toxicity in high-doses was often diagnosed by the presence of many glycosides. The potential mutagenicity of P. sepium was investigated both in vitro and in vivo. Methods: This was examined by the bacterial reverse mutation (Ames) test using Escherichia coli WP2uvrA and Salmonella typhimurium strains, such as TA98, TA100, TA1535, and TA1537. Chromosomal aberrations were investigated using Chinese hamster lung cells, and the micronucleus test using mice. Results: P. sepium did not induce mutagenicity in the bacterial test or chromosomal aberrations in Chinese hamster lung cells, although metabolic activation and micronucleated polychromatic erythrocytes were seen in the mice bone marrow cells. Conclusions: Considering these results, it is suggested that P. sepium does not have mutagenic potential under the conditions examined in each study.

Parameter Analysis of Platinum Silicide Rectifier Junctions acceding to measurement Temperature Variations (측정 온도 변화에 따른 백금실리사이드 정류성 접합의 파라미터 분석)

  • 장창덕;이용재
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 1998.05a
    • /
    • pp.405-408
    • /
    • 1998
  • In this paper, We analyzed the current-voltage characteristics with n-type silicon substrates concentration and temperature variations (Room temperature, 5$0^{\circ}C$, 75$^{\circ}C$) in platinum silicide and silicon junction. Measurement electrical parameters are forward turn-on voltage, reverse breakdown voltage, barrier height, saturation current, ideality factor, dynamic resistance acceding to junction concentration of substrates and temperature variations. As a result, the forward turn-on voltage, reverse breakdown voltage, barrier height and dynamic resistance were decreased but saturation current and ideality factor were increased by substrates concentration variations. Reverse breakdown voltage and dynamic resistance were increased by temperature variations.

  • PDF

Analysis and Countermeasures for the Trouble Factors of the Spot Installation Pile Using Machine Excavation Method (기계굴착공법을 적용한 현장타설말뚝 시공시 부조화 발생요인 분석 및 대응 방안)

  • Park, Hong-Tae;Son, Chang-Baek
    • Journal of the Korea Institute of Building Construction
    • /
    • v.9 no.4
    • /
    • pp.75-83
    • /
    • 2009
  • Although a range of machine excavation methods are in wide use, including casing, earth drill and reverse circulation drilling, deterioration in pile quality and faulty construction can be often found these days because of trouble in the construction field. For this study, research was conducted in the form of a survey of construction engineers working in the field in order to identify the types and the causes of trouble by focusing on all casing, earth drilling and reverse circulation drilling. By analyzing the causes of trouble, countermeasures could be presented. The data and the analysts presented in this study could be effectively used for minimizing trouble in future machine excavation work during construction.