2,513 research outputs found

    Image compression based on 2D Discrete Fourier Transform and matrix minimization algorithm

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    In the present era of the internet and multimedia, image compression techniques are essential to improve image and video performance in terms of storage space, network bandwidth usage, and secure transmission. A number of image compression methods are available with largely differing compression ratios and coding complexity. In this paper we propose a new method for compressing high-resolution images based on the Discrete Fourier Transform (DFT) and Matrix Minimization (MM) algorithm. The method consists of transforming an image by DFT yielding the real and imaginary components. A quantization process is applied to both components independently aiming at increasing the number of high frequency coefficients. The real component matrix is separated into Low Frequency Coefficients (LFC) and High Frequency Coefficients (HFC). Finally, the MM algorithm followed by arithmetic coding is applied to the LFC and HFC matrices. The decompression algorithm decodes the data in reverse order. A sequential search algorithm is used to decode the data from the MM matrix. Thereafter, all decoded LFC and HFC values are combined into one matrix followed by the inverse DFT. Results demonstrate that the proposed method yields high compression ratios over 98% for structured light images with good image reconstruction. Moreover, it is shown that the proposed method compares favorably with the JPEG technique based on compression ratios and image quality

    Experiments on Passive Hypervelocity Boundary-Layer Control Using an Ultrasonically Absorptive Surface

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    Recently performed linear stability analyses suggested that transition could be delayed in hypersonic boundary layers by using an ultrasonically absorptive surface to damp the second mode (Mack mode). Boundary-layer transition experiments were performed on a sharp 5.06-deg half-angle round cone at zero angle of attack in the T5 Hypervelocity Shock Tunnel to test this concept. The cone was constructed with a smooth surface around half the cone circumference (to serve as a control) and an acoustically absorptive porous surface on the other half. Test gases investigated included nitrogen and carbon dioxide at M∞ ≃ 5 with specific reservoir enthalpy ranging from 1.3 to 13.0 MJ/kg and reservoir pressure ranging from 9.0 to 50.0 MPa. Comparisons were performed to ensure that previous results obtained in similar experiments (on a regular smooth surface) were reproduced, and the results were extended to examine the effects of the porous surface. These experiments indicated that the porous surface was highly effective in delaying transition provided that the pore size was significantly smaller than the viscous length scale

    Fluoride in the drinking water of Pakistan and the possible risk of crippling fluorosis

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    To explore the possibility of fluoride toxicity, 747 water samples were collected from surface water and groundwater sources of 16 major cities of Pakistan, adopting a uniform sampling design with distribution of samples: Lahore (79), Kasur (46), Faisalabad (30), Khushab (50), Chakwal (51), Mianwali (30), Jhelum (53), Bahawalpur (60), Karachi (60), Mirpur Khas (55), Peshawar (38), Risalpur (35), Quetta (81), Ziarat (21), Loralai (21), and Mastung (37). Comparison of analytical findings with WHO Guidelines of Drinking Water for Fluoride (i.e., 1.5 ppm) has concluded that 16% of the monitored water sources have fluoride concentration beyond the permissible safe limit of 1.5 mg L<sup>&minus;1</sup> falling in the concentration range of 1.6&ndash;25 mg L<sup>&minus;1</sup>. The highest fluoride contamination (22%) is detected in the Balochistan province followed by 19% in Punjab province. Comparatively higher fluoride levels of > 20% in the groundwater sources like hand pumps supported the possibility of increased groundwater contamination as excessive fluoride concentrations are expected to come from calcium-poor aquifers and in areas where fluoride-bearing minerals are common or where cation exchange of sodium for calcium occurs. Field observations have also indicated the prevalence of fluoride-associated health implications in the study areas with excessive fluoride in water sources. Findings of this study have provided bidirectional vision for the epidemiological investigations as well as to mitigate the issues in the affected vicinities of fluoride-rich areas

    What Explains the Current High Rate of Inflation in Pakistan?

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    One of the most significant developments in the current economic scene in Pakistan has been the sharp increase in the rate of inflation. The annual average rate of increase in the wholesale price index (WPI) during the first seven months (July-January 1994-95) of the current fiscal year has been about 19 percent as opposed to 11.3 percent during the same period last year. A similar increase was also witnessed in the consumer price index (CPI) which accelerated to 13 percent as opposed to 11.1 percent during the previous period. Such a sharp increase in prices in recent months has not only caused alarm in the academic circles but has equally disturbed the country’s chief executive, the Prime Minister. The recent surge of inflation is a matter of serious concern for a variety of reasons. First, Pakistan has been a low-inflation country as it has experienced price stability during the last three decades. The rate of inflation, as measured by an increase in the WPI, averaged 2.6 percent during the 1960s. The components of the WPI, i.e., food, raw materials, manufactures, and fuel and lubricants, also grew by an average rate ranging from 2.0 to 3.4 percent p.a. during then 1960s (see Table 1 for relevant statistics). The rate of inflation crossed the single-digit threshold during the 1970s. The WPI and its components increased at an annual average rate ranging from 12 to 18 percent. The double-digit inflation during the 1970s has been the result of two major oil shocks, a massive devaluation of currency, and devastating floods destroying agricultural crops. Pakistan returned to the fold of the single-digit inflation during the 1980s. The rate of inflation remained at the single-digit level during the first three years of the 1990s with the exception of 1990-91, when the rate of inflation increased to 11.7 percent as a result of the Gulf War. It is only during the outgoing fiscal year and in the current year that the rising inflation is posing a major threat to macroeconomic stability.

    Report on Tell al-Imsihli: The 2000 and 2001 Seasons

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    This article summarizes two seasons of excavations at Tell al-Imsihly, a prehistoric site nearly 5 kilometers south of Assur. Archaeological excavations were conducted by Iraq’s State Board of Antiquities and Heritage (SBAH) over a period of two seasons starting in April 2000 and ending in late 2001. Iraqi archaeologists working at Assur were put in charge of investigating the site. Due to damage and incursions on the site from plowing and earthmoving activities, the goals of SBAH’s excavations were to obtain an idea of settlement chronology and activity within and just outside of Tell al-Imsihly. In 2006-2007, Dr. Altaweel collaborated with the Iraqi archaeologists who had excavated the site in order to assist in interpreting some of the archaeological data as well as publication of the excavations to a wide audience. Some original items and records from the excavations are not currently available, and perhaps lost, but the archaeological report compiled by Mr. Hamza and written in Arabic remains. In addition, many of the ceramic drawings and excavation photographs have survived. The data presented by the Arabic report are the basis of the presentation to follow, although some additional details have been provided by Altaweel

    Role of ficus carica Leaves Extract in Treatment of Hypothyroidism

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    أجريت هذه الدراسة لتوضيح دور المستخلص الكحولي لأوراق التين في علاج مرض قصور الغدة الدرقية المستحث بالكاربيمازول. اربعين من ذكور الجرذان البيض أختيرت وقسمت الى خمسة مجاميع وكل مجموعة ضمت ثمانية جرذان, المجموعة الاولى عدت سيطرة سالبة وجرعت بمحلول الملح الفسلجي لوحده, بينما الثانية عدت كمجموعة سيطرة موجبة وجرعت بعقار الكاربيمازول&nbsp; وحده لأستحثاث قصور الغدة الدرقية ولمدة ستة أسابيع, بينما عوملت المجموعة الثالثة بالمستخلص الكحولي لأوراق التين وحده&nbsp; بتركيز500 ملغم /كغم لمدة ستة أسابيع , بينما جرعت المجموعة الرابعة بعقار الكاربيمازول 5 ملغم /كغم&nbsp; لمدة ستة أسابيع وفيما بعد عولجت بالمستخلص الكحولي لأوراق التين بتركيز500 ملغم /كغم لمدة ستة أسابيع, في حين جرعت المجموعة الخامسة بعقار الكاربيمازول لمدة ستة أسابيع وعولجت فيما بعد بواسطة عقار الثايروكسين 100 ملغم /كغم ولمد ستة أسابيع ايضا. أوضحت النتائج عدم وجود فرق معنوي &nbsp;(P&lt;0.05)في معدل الكسب الوزني في حيوانات المجموعة الرابعة (الكاربيمازول مع المستخلص النباتي)عند مقارنتها مع المجاميع الأولى (محلول الملح الوظيفي لوحده) والثانية (عقار الكاربيمازول وحده) والثالثة (المستخلص النباتي لوحده) , وكذلك وجود زيادة معنوية &nbsp;(P&lt;0.05)عند مقارنتها بحيوانات المجموعة الخامسة (الكاربيمازول مع عقار الثايروكسين) . كما أشارت النتائج الى عدم وجود فرق معنوي &nbsp;(P&lt;0.05)في تركيز هرموني الغدة الدرقية T3 , T4 &nbsp;في المجاميع الثالثة (المستخلص النباتي لوحده) والرابعة (الكاربيمازول مع المستخلص النباتي) والخامسة (الكاربيمازول مع عقار الثايروكسين) عندما قورنت بالمجموعة الأولى (محلول الملح الوظيفي لوحده), وكذلك وجود زيادة معنوية &nbsp;(P&lt;0.05)عندما قورنت بالمجموعة الثانية (عقار الكاربيمازول وحده), أما بالنسبة لتركيز الهرمون المحفز للغدة الدرقية TSH فقد بينت النتائج عدم وجود فرق معنوي (P&lt;0.05) في تركيز المجاميع الرابعة (الكاربيمازول مع المستخلص النباتي) والخامسة (الكاربيمازول مع عقار الثايروكسين) والمجموعة الثالثة (المستخلص النباتي لوحده) عند مقارنتها بالمجموعة الأولى(محلول الملح الوظيفي لوحده)&nbsp; وكذلك وجود نقص معنوي(P&lt;0.05)&nbsp; عندما قورنت بالمجموعة الثانية (عقار الكاربيمازول وحده). أستنتجت الدراسة الحالية أمكانية أستخدام المستخلص الميثانولي لأوراق التين في تنظيم ميكانيكية افراز هرمونات الغدة الدرقية وذلك لأحتواءه على مكونات كيماوية مؤثرة على ميكانيكية أنتاج افراز هرمونات الغدة الدرقية وبالتالي كبح خطورة مرض قصور الغدة الدرقية.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; This study was conducted to demonstrate the role of&nbsp; alcoholic extract from ficus carica leaves in the treatment&nbsp; of&nbsp; hypothyroidism disease which induced by carbimazole drug. Forty&nbsp; male rats were divided into five&nbsp; groups,&nbsp; eight&nbsp; for each . group I selected as negative control &nbsp;and administered orally with normal saline alone, group II served as positive control and treated by carbimazole anti-thyroid&nbsp; drug for six weeks , &nbsp;group &nbsp;III &nbsp;was treated by plant extract (500 mg /kg, bw) for six weeks, the&nbsp; fourth group IV was treated by carbimazole drug (5 mg) for six week to induce hypothyroidism &nbsp;&nbsp;and then &nbsp;treated by plant extract (500 mg /kg , bw) , and the fifth V group was&nbsp; treated by thyroxin drug (100 mg) for six week instead of plant extract. &nbsp; &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The results showed&nbsp; insignificant differences (P&lt;0.05) in body weight gain in the fourth&nbsp; group ( carbimazole and plant extract) when compared&nbsp; with the first&nbsp; group (normal saline alone), second group (carbimazole alone), third group (plant extract alone&nbsp; , while the results demonstrated&nbsp; that a significant&nbsp; increase (P&lt;0.05)&nbsp;&nbsp; in body weight gain when&nbsp; compared with fifth groups (carbimazole and thyroxine). While the results revealed insignificant differences (P&lt;0.05) in the concentrations of&nbsp; T3 and T4&nbsp; in the fourth (carbimazole &amp; plant extract), fifth&nbsp; groups&nbsp; (carbimazole &amp; thyroxin drug ) and the&nbsp; third group (plant extract alone) when compared&nbsp; with the first&nbsp; group ( normal saline alone ), but&nbsp; there was&nbsp; a significant increase (P&lt;0.05)&nbsp; when compared with the&nbsp; second group (carbimazole alone) , in addition&nbsp; the&nbsp; results indicated a significant decrease (P&lt;0.05) when compared&nbsp; with the third&nbsp; group, Furthermore, the results revealed insignificant difference (P&lt;0.05) in TSH concentration in the fourth (carbimazole &amp; plant extract), fifth groups (carbimazole &amp; thyroxin drug)&nbsp;&nbsp; and the&nbsp; third group (plant extract alone) when compared&nbsp; with the first&nbsp; group (normal saline alone) , also the data showed a significant decrease(P&lt;0.05) when compared with the&nbsp; second group (carbimazole alone). In conclusion, it is possible to use methanolic plant extract from ficus carica leaves in the regulation of hypothyroidism due to the presence of phytochemical components&nbsp;that can affect&nbsp;the mechanism of T3 and T4 production by the thyroid gland.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &nbsp

    Considering Green Corridors in Road Networks: An Integrated Gray-Green approach for Urban Development in Cairo, Egypt.

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    Green corridors are one of the main features for sustainability, they refer to ecological qualities and are basic elements for resilient cities. Many global cities are oriented towards green construction to protect their environments from rapid urbanization and its destructive impact on nature. However, in other cities, this is extremely challenging. In Cairo, contemporary developments are directed towards constructing the ‘Gray’ road networks, whereas the ‘Green’ is nearly disappearing. This study introduces an integrated ‘Gray-Green’ approach for urban development in Cairo, where green corridors are considered to achieve a livable sustainable urban environment. First, the study discusses characteristics, benefits and challenges for green corridor construction. Then, it presents three different visions and approaches for three international projects adopting green corridor concepts within their urban development. The study then depends on a comparative analysis between the three mentioned projects and the fourth case in Cairo. This analysis explores themes, objectives, challenges and actions for each project in order to conclude a proposed action plan for Cairo. This plan is considered an adaptive process for fostering environmental, social and economic sustainability in Cairo

    Using nano silica to enhance the performance of recycled asphalt mixtures

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    Understanding how the physical properties of Nano-silica material affect the ultimate implementation of the asphalt binder is an essential study area that has been disregarded previously. The current investigation aims to determine whether or not it was possible to change the asphalt binder with Nano-silica (NS) depending on the qualities of the asphalt binder under consideration. Using nano-silica (2, 4, and 6 percentage by weight of asphalt), a penetration grade asphalt cement with 60/70 was developed. Nano silica and asphalt cement were first tested for their qualities. The NS modified asphalt binder was ready for use in the experiment after being heated to 160°C and mixed with a shear mixer at 2000 rpm for 60 minutes. The softening point temperature and penetration index of the NS modified asphalt binder, as well as the Brookfield rotational viscosity and ductility data, were also evaluated. Based on the rheological performance of the NS modified asphalt binder, increasing Nano silica content increases stiffness while decreasing temperature sensitivity. The addition of 4% Nano silica (NS) asphalt binder improved its basic properties and allowed it to be used in hot weather. By adding 4% NS to the hot recycle asphalt mixture, the Marshall stability is increased by 32.5%, the flow is reduced by 21.4%, the unit weight is maintained, and the amount of air voids in the mix, as well as other mix qualities, are kept at acceptable ranges. It'll also boost the ITS by 37.8%. In general, adding NS to asphalt mixtures improves their qualities

    Investigating visibility affordance, knowledge transfer and employee agility performance. A study of enterprise social media

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    The research analyzes the associations between enterprise social media (ESM) visibility affordance (i.e., message transparency and network translucence) and employee agility performance through knowledge transfer (knowledge acquisition and knowledge provision) in organizations that have applied ESM. Utilizing the communication visibility theory, this study further examines the moderating role of task interdependence in strengthening the interactions between knowledge transfer and employee agility performance. We conducted two studies, one in China (347 samples) and the other in the United States (335 samples) to cross-culturally test our research model. Our results indicate that message transparency and network translucence have significant positive associations with employee agility performance in both studies. The findings also show that knowledge provision mediates the relationships between ESM visibility affordance and employee agility performance in both samples, while knowledge acquisition mediates the association between ESM visibility affordance and employee agility performance in the Chinese sample but not in the U.S. sample. Further, task interdependence moderates the link between knowledge acquisition and employee agility performance in China and the United States. However, task interdependence moderates the relationship between knowledge provision and employee agility performance in China but not in the United States. The implications for theory and management are also discussed
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