1,006 research outputs found
Enhanced cryptographic approaches for SCADA network security.
Due to the overwhelming increase in open source code, off-the-shelf software packages, third party and vendor codes, along with the ease of getting information about hacking network security systems and attacking the well known holes in security systems, the problem of having a secure network system is much more difficult than before this boom in technology and information broadcast. What makes the problem even worse is trying to secure a network for real time control, such as a network using supervisory control and data acquisition (SCADA) systems, because now the problem has two faces: securing the real time control system and at the same time keeping the response time of the system in the acceptable range for the transactions\u27 level of service. There is a strong trend to chose security frameworks that have been popular in the e-commerce sites of the web, particularly because they proven to be very mature and secure for more than one and half decades. Examples include the transport level security (TLS) and its predecessor secured socket layer (SSL) framework that is based on the very popular public key cryptography and key distribution algorithms, such as Rivest, Shamir and Adleman (RSA), elliptic curve cryptography (ECC), and Diffie-Hellman. Despite the fact that these algorithms proved to be very powerful against most types of attacks, they are not tailored to secure SCADA networks, and consequently cause a significant degradation in the performance time of real time transactions. This dissertation offers two novel encryption algorithms for securing a SCADA network, the N-Secrecy and the Security Spectrum algorithms. N-Secrecy gave very good results when compared with the SSL; with N-Secrecy performance time in the range of one thousandth of the SSL. The Security Spectrum approach moved the encryption methodology from using numerical representations into using a physical representation based on modeling the conditions of the two communicating parties with a system of non-linear polynomials and then using computer algebra techniques. Both approaches have the potential to significantly enhance the security of commercial SCADA installations
Ephemerides of Visual Binaries of highly eccentric orbits
Ephemerides of binary stars are important information for astronomical observation and research. In this paper, ephemerides of the visual binaries ADS784, ADS13665, A1529, ADS836, ADS 3434, ADS1105 and ADS 3315 have been calculated using a computational algorithm to the successive approximations method. Ephemerides prediction to the visual binary systems of highly eccentric orbits is evaluated up to the year 2021. Comparisons with the observations are in good agreement
Antidote Stocking at Hospitals in North Palestine
Objective: The purpose of this study was to determine the availability and adequacy of antidote stocking at hospitals in north Palestine based on published guidelines for antidote stocking.
Methodology: This study is a cross sectional survey of all hospitals at north Palestine (n=11) using a questionnaire which was completed by the director of the pharmacy department at each hospital. The questionnaire was divided into 2 parts. The first part contained a list of 25 antidotes while the second part contained a list of 12 antidotes. This classification is based on the guideline proposed by the British Association for Emergency Medicine (BAEM). The net antidote stock results were compared with the American guidelines as well.
Result: The overall availability of each antidote in the first list varied widely from zero for glucagon to 100% for atropine. The number antidotes of the first list that were stocked in the 11 hospitals ranged from 5 to 12 antidotes but none of the hospitals stocked all the 25 antidotes. Additionally, availability of antidotes in the second list varied widely from zero for polyethylene glycol to 100% for dobutamine. The number of antidotes stocked ranged from 5 to 9 but none of the hospitals stocked all the 12 antidotes.
Discussion and Conclusion: hospitals in north Palestine do not have adequate stock of antidotes. Raising awareness of the importance of antidotes by education, regular review of antidote storage, distribution plans, and appropriate legislation might provide solutions. Coordination between Palestinian hospitals and the PCDIC at An-Najah National University is also important
The Effect of Using Six Dimensional Strategy PDEODE in Teaching Science on the Basic Eighth Grade Students' Achievement and their Attitudes towards it
The study aimed to investigate the effect of using PDEODE strategy on the eighth grade students’ achievement in science and their attitudes towards the strategy. To achieve the objectives of the study, a sample of eighth grade students was selected, consisting of 61 students distributed in two groups: an experimental of 31 female students who studied science using PDEODE strategy, and a control group of 30 female students who studied via the regular method. Two instruments were built; The first was an achievement test, which was applied on both groups before and after treatment, and the second was an attitude scale, which was applied on the experimental group after treatment. The results revealed that there is a statistically significant difference in the achievement of female students attributed to the teaching strategy on the test level as a whole, and at the level of knowledge fields (remembering, understanding, analyzing), for the benefit of the experimental group. There were, however, no differences between the two groups at the applying level. The results also indicated that the attitudes of students in the experimental group towards learning with PDEODE strategy were high and positive
Study and Evaluation of Geotechnical Properties of Soil Banks Slopes for Al-Masab Al-Aam Channel (Southern Sector) and the Possibility of Improving Them. Iraq
تضمنت هذه الدراسة منحدرات الضفاف في القطاع الجنوبي لقناة المصب العام جنوب العراق. تمت دراسة الخواص الجيوتقنية للتربة على ضفاف القناة متضمنة الخواص الفيزيائية والهندسية والكيميائية بواقع (15) محطة. أظهر توزيع حجم الحبيبات للتربة أن نسبة الرمل كانت أعلى من نسبة الطين والطمي.
وفقا للتصنيف الموحد( USCS) للتربة في منطقة الدراسة يمكن أن تصنف الى طين ذو اللدونة المنخفضة (CL) والذي يمثل 33.3٪ من التربة ، والطين ذو اللدونة العالية (CH) يمثل 20٪ من التربة وغير اللدنة (SM) تمثل 46٪ ، وتتراوح قيم الكثافة الجافة بين (1.51-1.86) غم/سم3 ، وتتراوح قيم الكثافة المشبعة بين (1.61-2.2) غم/سم3 ، وتتراوح قيم المحتوى المائي بين (25.2-42٪). بينما تتراوح قيم الوزن النوعي بين (2.51-2.74) ، وتراوحت زاوية الاحتكاك الداخلي (Ø°) من اختبار القص المباشر بين (21.5-37°). وتتراوح قيم اختبار الانضغاط غير المحصور بين (37-126.2) كيلو نيوتن / م2 للعينات المعاد تشكيلها بنسبة 25٪ ماء ، تتراوح قيم الكلورايد بين (0.053-0.195%), بينما تراوحت قيم الكبريتات بين (0.35 – 9.75٪) ، بينما تتراوح تركيزات الكربونات بين (15- 50٪) تتراوح تراكيز المواد العضوية بين (0.140 - 1.125٪). تتراوح قيمة الأس الهيدروجيني بين (7.5-9). وبناء على هذه النتائج تم تقييم استقرار منحدرات ضفاف المجرى العام للمصب (المنطقة الجنوبية) واقتراح الحلول المناسبة لدعم استقرارها ومعالجة غير المستقرة.This study is concerned with channel banks slopes in the southern sector for Al-Masab Al-Aam channel south of Iraq. The geotechnical properties of the soil in the banks of the channel including the physical, engineering and chemical properties of (15) stations were studied. The grain size distribution of soil showed that the proportion of sand was higher than that of clay and silt.
Based on the USCS standards of soil of the study area can be classified as clay with low plasticity (CL) that represents 33.3% of the soil and ,clay with high plasticity (CH) represents 20% of the soil and nonplasticity (SM) represents 46%.The dry density values range between (1.51-1.86) g/cm3 , the saturated density values range between (1.61-2.2) g/cm3, and the water content values range between (25.2-42%), while the specific gravity values range between (2.51-2.74 ).The internal friction angle (Ø°)from direct shear test ranged between (21.5-37°). The values of unconfined compression test range between (37-126.2) kN/m2 of remolded samples with 25% water, The values of chloride range between (0.053-0.195%), while the values of sulfate range between (0.053-0.195%), the carbonates concentrations range between (15-50%), the organic materials concentrations range between (0.140-1.125%), The pH value range between (7.5-9). According to these results, the stability of the ramps of the banks of the downstream general channel (Southern District) was evaluated and appropriate solutions were proposed to support their stability and treat the unstable ones
The Level of Understanding of the Nature of Science among the Biology Teachers in the Directorate of Irbid and Its Relation to the Level of their Explanation of Biological Phenomena
هدفت الدراسة التعرف إلى مستوى فهم معلمي الأحياء لطبيعة العلم، وعلاقته بمستوى تفسيرهم للظواهر البيولوجية. وتكونت عينة الدراسة من 120 معلماً ومعلمة يدرّسون مادة الأحياء في مديرية لواء قصبة إربد. ولتحقيق أهداف الدراسة طُوّر اختبار يقيس مستوى فهم معلمي الأحياء لطبيعة العلم، كما أُعدّ اختبار آخر يقيس مستوى تفسير معلمي الأحياء للظواهر البيولوجية، وطبقا على عينة الدراسة. أشارت نتائج الدراسة إلى أن مستوى فهم معلمي الأحياء لطبيعة العلم كان بدرجة متوسطة على الاختبار ككل، وعلى كل بعد من أبعاده، وعدم وجود فروق دالة في مستوى فهم معلمي الأحياء لطبيعة العلم تعزى لأثر كل من جنس المعلم، وسنوات خبرته، والتفاعل بينهما. وأشارت النتائج أن مستوى تفسير معلمي ومعلمات الأحياء للظواهر البيولوجية كان مرتفعاً، وعدم وجود فروق دالة في مستوى قدرة المعلمين على تفسير الظواهر البيولوجية تعزى لأثر كل من جنس المعلم، وسنوات خبرته، والتفاعل بينهما. كما أشارت النتائج إلى وجود علاقة ارتباطية دالة بين مستوى فهم معلمي الأحياء لطبيعة العلم، وقدرتهم على تفسير الظواهر البيولوجية.The study aimed to identify the level of understanding of the nature of science among the Biology teachers in the directorate of Irbid and its relation to the level of their explanation of Biological phenomena. The sample of the study comprised 120 teachers who teach biology in the directorate of Irbid Kasbah district. A test was developed to measure the level of teachers' understanding of the nature of science. Another test was developed to measure the level of teachers' explanation of the biological phenomenon. The tools was applied on the sample study. The results pointed out a moderate degree of teachers' understanding of the nature of science, and showed that there were no significant differences in the level of teachers' understanding due to their gender, the number of years of experience, or the interaction between them. In addition, the results pointed out a high degree of teachers' explanation of biological phenomena, and there were no significant differences in the ability of teachers to explain the biological phenomenon due to their gender, the years of experience or the interaction between them. In addition, the findings revealed a significant correlation between teachers' understanding of the nature of science and their ability to explain biological phenomena
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