دانلود و نمایش مقالات مرتبط با WAR::صفحه 1
اربعین
نتیجه جستجو - WAR

تعداد مقالات یافته شده: 2239
ردیف عنوان نوع
1 بازیابی انتخابی کبالت از جریان های ثانویه پس از فرآوری باتری های NIMH با استفاده از سیانکس 301
سال انتشار: 2019 - تعداد صفحات فایل pdf انگلیسی: 8 - تعداد صفحات فایل doc فارسی: 29
کبالت به عنوان یک ماده خام اساسی برای اتحادیه اروپا تلقی می شود. از آنجاییکه تامین محدودی دارد تلاشهای قابل توجهی باید برای توسعه روشهای ماندگار جهت بازیافت کبالت از منابع جایگزین صورت گیرد. فرآوری هیدرومتالورژیکی باتری های مصرف شده NiMH یک جریان متمرکزی حاوی کبالت (8/11 گرم بر لیتر) و ناخالصی ها (3/2 گرم بر لیتر نیکل، 2/0 گرم بر لیتر آلومینیوم، 3/9 گرم بر لیتر منگنز و 6/4 گرم بر لیتر عناصر کمیاب زمین) در بستر اسید نیتریک تولید می کند. در این مطالعه، جداسازی انتخابی کبالت از سایر یونهای موجود بررسی شد. کبالت به صورت انتخابی از آلومینیوم، منگنز و عناصر کمیاب زمین با استفاده از یک مولار سیانکس 301 در کروسن جداسازی شد. از رفتار سنتیکی متفاوت درطی استخراج با سیانکس 301 برای جداسازی یونهای کبالت و نیکل به صورت انتخابی استفاده شد. آنتالپی محاسبه شده برای فرآیند استخراج کبالت برابر است با – 11.37 ± 0.5 kJ/ که بیانگر این است که استخراج کبالت در سیستم بررسی شده یک واکنش گرمازا می باشد. از تاثیر دما روی استخراج کبالت برای دستیابی به انتخابی بودن بهتر برای نیکل استفاده شد. کبالت ازطریق زدایش انتخابی با 4 مولار اسید کلریدریک در دمای محیط بازیافت شد. خلوص نهایی محصول زدایش برابر با 9/99 درصد بود.
مقاله ترجمه شده
2 Problems of engineering entrepreneurship in Africa: A design optimization example in solar thermal engineering
مشکلات کارآفرینی مهندسی در آفریقا: یک نمونه بهینه سازی طراحی در مهندسی حرارتی خورشیدی-2019
This paper addresses Africa’s challenges and opportunities to engineering entrepreneurs. A business environmental scan is done in line with the standard PESTLE analysis, identifying at least twenty generic problems across the continent. Focus is directed to an opportunity in solar water heating, where inadequate electricity supply combines with a plentiful solar resource amidst environmental protection awareness, to make investments potentially worthwhile. Three home level market segments are identified. Key issues in the PESTLE scan are linked with available materials to formulate and solve a design optimization model for these segments. A competition-less product emerges for rural homes. Another – for small urban homes – can be retailed at 50% of current equivalent system prices, and yet, still make profits for the entrepreneur. Both these systems attain average temperatures in excess of 57 C, the fatal level for most pathogenic bacteria. The 3rd and larger system for rich urban homes incorporates a supplementary electric heater that is programmable to kick in half an hour before water withdrawal if solar energy has failed to maintain water temperature above 60 C. The entrepreneur can still make profit if the product retails at 52% of the equivalent competition price.
Keywords: Africa | Design optimization | Engineering entrepreneurship | PESTLE analysis | Solar water heating
مقاله انگلیسی
3 Abstract depiction of human figures in impressionist art and children’s picture books
چکیده ای از چهره های انسان در هنرهای تجسمی و کتاب های تصویری کودکان-2019
The human figure is important in art. I discuss examples of the abstract depiction of the human figure, from both impressionist painting and children’s book illustration, and the challenge faced in algorithmically mimicking what human artists can achieve. I demonstrate that there are excellent examples in both genres that provide insight into what a human artist sees as important in providing abstraction at different levels of detail. The challenge lies in the human brain having enormous knowledge about the world and an ability to make fine distinctions about other humans from posture, clothing and expression. This allows a human to make assumptions about human figures from a tiny amount of data, and allows a human artist to take advantage of this when creating art. The question for the computer graphics community is whether and how we could algorithmically mimic what a human artist can do. I provide evidence from both genres to suggest possible ways forward.
Keywords: Impressionism | Abstraction | Representation | Perception
مقاله انگلیسی
4 خوشامدگویی یا نه؟ - حس امنیت، تعلق خاطر و نگرش های افراد بومی نسبت به فرهنگ پذیری مهاجران
سال انتشار: 2019 - تعداد صفحات فایل pdf انگلیسی: 8 - تعداد صفحات فایل doc فارسی: 25
تنوع فرهنگی به دلیل مهاجرت تبدیل به یک وضوع کلیدی در بسیاری از جوامع امروزی شده است. این سوال که چگونه جمعیت بومی این توسعه ها را تجربه می کند دارای اهمیتی اساسی برای روابط بین فرهنگی است و پایه ای را برای فرهنگ پذیری مهاجران ایجاد می کند. ما با الهام از تحقیقات مربوط به تعلق خاطر و چند فرهنگی بودن، در اینجا فرض می کنیم که حس امنیت عمومی و خصوصی می تواند به نگرش های مثبت تر به تنوع فرهنگی مربوط شود درحالیکه حس تهدید می تواند به آزادی کمتر مربوط شود. به صورت صریح تر، مطالعه حاضر به بررسی این موضوع پرداخته است که چگونه تعلق خاطر عمومی افراد بومی (امن یا ترسان) و نیز حس امنیت (فرهنگی یا اقتصادی) خاص آنها می تواند به تجربیات آنها درباره فرهنگ پذیری مهاجران در کشور چند فرهنگه لوکزامبورگ مربوط شود. نمونه ما شامل 134 فرد لوکزامبورگی با میانگین سنی 02/45 (انحراف معیار 41/17) بود که یک پرسشنامه آنلاین را پر کردند. نتایج نشان داد که تعلق خاطر عمومی خود – گزارش شده توسط افراد ترسان رابطه ای مثبت با جهت گیری های غیر خوشامدگویانه ترِ فرهنگ پذیری دارد. روابط بین تعلق خاطر عمومی و جهت گیری های فرهنگ پذیری توسط حس امنیت فرهنگی وساطت می شود که تاثیراتی قوی روی جهت گیری های (غیر) خوشامدگویانه افراد بومی نسبت به دلستگی عمومی دارند. یافته ها بیانگر این هستند که جهت گیری های غیر خوشامدگویانه درقبال مهاجران که شامل آزادی برای برقراری رابطه و تبادل فرهنگی می شود، با حس امنیت فرهنگی و اقتصادی که به صورت جزئی توسط یک تعلق خاطر عمومی امن یا ترسان منحرف می شود، رابطه دارد. بنابراین به نظر می رسد که حس امنیت یک پایه امنی را برای دامنه و آزادی تنوع فرهنگی فراهم می کند که به منظور مواجهه موفقیت آمیز با چالش های جوامع چند فرهنگه امروزی مورد نیاز هستند.
مقاله ترجمه شده
5 Mining patient-specific and contextual data with machine learning technologies to predict cancellation of children’s surgery
استخراج داده های خاص و اختصاصی بیمار با فناوری های یادگیری ماشین برای پیش بینی لغو جراحی کودکان-2019
Background: Last-minute surgery cancellation represents a major wastage of resources and can cause significant inconvenience to patients. Our objectives in this study were: 1) To develop predictive models of last-minute surgery cancellation, utilizing machine learning technologies, from patient-specific and contextual data from two distinct pediatric surgical sites of a single institution; and 2) to identify specific key predictors that impact children’s risk of day-of-surgery cancellation. Methods and findings: We extracted five-year datasets (2012–2017) from the Electronic Health Record at Cincinnati Children’s Hospital Medical Center. By leveraging patient-specific information and contextual data, machine learning classifiers were developed to predict all patient-related cancellations and the most frequent four cancellation causes individually (patient illness, “no show,” NPO violation and refusal to undergo surgery by either patient or family). Model performance was evaluated by the area under the receiver operating characteristic curve (AUC) using ten-fold cross-validation. The best performance for predicting all-cause surgery cancellation was generated by gradient-boosted logistic regression models, with AUC 0.781 (95% CI: [0.764,0.797]) and 0.740 (95% CI: [0.726,0.771]) for the two campuses. Of the four most frequent individual causes of cancellation, “no show” and NPO violation were predicted better than patient illness or patient/family refusal. Models showed good cross-campus generalizability (AUC: 0.725/0.735, when training on one site and testing on the other). To synthesize a human-oriented conceptualization of pediatric surgery cancellation, an iterative step-forward approach was applied to identify key predictors which may inform the design of future preventive interventions. Conclusions: Our study demonstrated the capacity of machine learning models for predicting pediatric patients at risk of last-minute surgery cancellation and providing useful insight into root causes of cancellation. The approach offers the promise of targeted interventions to significantly decrease both healthcare costs and also families’ negative experiences.
Keywords: Pediatric surgery cancellation | Quality improvement | Predictive modeling | Machine learning
مقاله انگلیسی
6 Sexually Transmitted Diseases Among US Adolescents and Young Adults
بیماریهای مقاربتی در بین نوجوانان و بزرگسالان آمریکایی-2019
Although sexually transmitted diseases (STDs) affect individuals of all ages, they take a particularly heavy toll on young people.  Expanded, integrated, multilevel approaches are warranted to reverse recent increases in STDs and improve sexual and reproductive health outcomes for adolescents and young adults in the United States.  Approaches must reach beyond clinics and school classrooms; capitalize on cuttingedge, youth-friendly technologies; and change social contexts in ways that encourage young people’s healthy sexual decision-making.
KEYWORDS : Adolescents | Young adults | Sexually transmitted diseases | Epidemiology | Clinical practice guidelines | Prevention
مقاله انگلیسی
7 Is leadership language ‘rewarded’ in crowdfunding? Replicating social entrepreneurship research in a rewards-based context
آیا زبان رهبری در تأمین مالی جمعیت پاداش می گیرد؟ تکرار تحقیقات کارآفرینی اجتماعی در یک زمینه مبتنی بر پاداش-2019
Rewards based crowdfunding (where individuals provide funding for a campaign in exchange for a pre-specified reward) represents one of the largest forms of crowdfunding to date. While an emerging stream of research examines how the rhetoric used in crowdfunding campaigns impacts funding success, a number of studies examining language used in crowdfunding have only been explored in the context of social crowdfunding campaigns that rely on very different audiences, funding amounts, and project goals. To build knowledge surrounding the relationship between the rhetoric used in rewards-based crowdfunding and potential campaign success we replicate a number of rhetoric approaches previously examined in social contexts. Specifically, we examine the efficacy of charismatic rhetoric, political rhetoric, entrepreneurial orientation rhetoric, and virtue rhetoric in a sample of 1000 campaigns drawn from Kickstarter. Our replication results reveal relatively little consistency across contexts underscoring the value of replication to understand boundary conditions of important entrepreneurial phenomena.
مقاله انگلیسی
8 The tacit knowledge of entrepreneurial design: Interrelating theory, practice and prescription in entrepreneurship research
دانش ضمنی در مورد طراحی کارآفرینی: نظریه ، عمل و تجویز در تحقیقات کارآفرینی-2019
An important challenge facing entrepreneurship researchers is the “three-body” knowledge problem of how to use “theoretical knowledge” to produce “prescriptive knowledge” that communicates the “practical knowledge” of situated practice to students and practitioners of entrepreneurship. We argue that a contribution can be made to solving this problem by theorizing practical knowledge as the “know-how” to do a situated entrepreneurial practice. “Know-how” is a cognitive “capacity to act” that prescribes for a practitioner how to produce a type of outcome in a range of circumstances. This “know-how” can potentially, therefore, be reconstructed theoretically as explicit micro-prescriptive guidelines for third-party practice. To exploit this connection between practical knowledge and prescriptive knowledge, however, we first need to overcome the problem that “know-how” is largely tacit in the moment of real-time forward-looking practice. In other words, the practitioner is not directly aware of their tacit “know-how”, or “tacit knowledge”, at the time of practice. In this article, we explore the contribution design theory can make to empirically eliciting, and conceptually inferring, the real-time “tacit knowledge” of entrepreneurial practice as a precursor to producing micro-prescriptive knowledge.
Keywords: Artifact | Design | Prescriptive knowledge | Tacit knowledge | Entrepreneurial practice | Problem space
مقاله انگلیسی
9 A multi-dimensional machine learning approach to predict advanced malware
یک روش یادگیری ماشین چند بعدی برای پیش بینی بدافزار پیشرفته-2019
The growth of cyber-attacks that are carried out with malware have become more sophisticated on al- most all networks. Furthermore, attacks with advanced malware have the greatest complexity which makes them very hard to detect. Advanced malware is able to obfuscate much of their traces through many mechanisms, such as metamorphic engines. Therefore, predictions and detections of such malware have become significant challenge for malware analyses mechanisms. In this paper, we propose a multi- dimensional machine learning approach to predict Stuxnet like malware from a dataset that consists of malware samples by using five distinguishing features of advanced malware. We define the features by analyzing advanced malware samples in the wild. Our approach uses regression models to predict ad- vanced malware. We create a malware dataset from existing datasets that contain real samples for ex- perimental purposes. Analyses results show that there are high correlations among some features of ad- vanced malware. These provide better predictions scores, such as R 2 = 0 . 8203 score for Stuxnet closeness feature. Experimental analyses show that our approach is able to predict Stuxnet like advanced malware if prediction features defined.
Keywords: Advanced malware | Machine learning | API Call | Prediction | Classification
مقاله انگلیسی
10 Evaluating solutions to the problem of false positives
ارزیابی راه حلهای مسئله مثبت کاذب-2019
A current challenge for the scientific community is the choice of appropriate policies to reduce the rate of false positives. Existing proposals differ in whether to prioritize tackling omission through transparency requirements, punishing more severe transgressions, or possibly both. We use a formal model to evaluate these possible solutions. We find that a policy that prohibitively increases the cost of ‘misdemeanor’ types of questionable research practices robustly decreases the overall rate of researcher misconduct, because the rate of ‘felonies’, such as fabrication, also decreases. Therefore proposals that aim to prevent lying by omission by enforcing reporting guidelines are likely to be effective in reducing researcher misconduct, but measures such as government audits (purported to counteract pure fraud) can backfire. Moreover, we find that an increase in the rewards of publication need not increase overall misconduct.
Keywords: Researcher misconduct | Reproducibility | False positives | Questionable research practices
مقاله انگلیسی
rss مقالات ترجمه شده rss مقالات انگلیسی rss کتاب های انگلیسی rss مقالات آموزشی