الأهداف: تُعد الثقة في اتخاذ قرارات الاستثمار من الأدوات الرئيسية لتقييم أسواق الأسهم. يتوجب على كل مستثمر تحديد أسعار الأسهم المستقبلية قبل تطوير استراتيجيات الاستثمار لتعزيز عائداتهم. ومع ذلك، فإن الطبيعة غير الخطية والمعقدة والمتقلبة والديناميكية لبيانات الأسهم تجعل من التنبؤ بأسعار الأسهم مهمة صعبة. تهدف هذه الدراسة إلى مواجهة هذه التحديات وتحسين دقة التنبؤ باستخدام تقنيات النمذجة المتقدمة. المنهجية: اقترحنا نموذجًا هجينًا للشبكات العصبية يدمج بين وحدات التكرار المغلقة ثنائية الاتجاه (BiGRU) والشبكات العصبية الالتفافية أحادية البعد (CNNs). تم إجراء تجارب على خمس مجموعات بيانات لأسعار الأسهم، تضمنت ثلاث أدوات أسهم فردية ومؤشرين للأداء في أسواق الأسهم. شملت معايير التقييم متوسط الخطأ المطلق (MAE) وجذر متوسط مربع الخطأ (RMSE). النتائج: حقق النموذج الهجين المقترح أدنى قيم للـ MAE لمجموعات البيانات الفردية، حيث تراوحت بين 0.357 و1.747. كما أظهرت التجارب انخفاضًا يتراوح بين 42% و91% في قيم RMSE مقارنةً بالأساليب القياسية المعتمدة على CNN وGRU، مما يعكس تحسنًا كبيرًا في دقة التنبؤ. الأبعاد: تشير النتائج إلى أن النموذج الهجين القائم على...

Spreadsheets are very common for information processing to support decision making by both professional developers and non-technical end users. Moreover, business intelligence and artificial intelligence are increasingly popular in the industry nowadays, where spreadsheets have been used as, or integrated into, intelligent or expert systems in various application domains. However, it has been repeatedly reported that faults often exist in operational spreadsheets, which could severely compromise the quality of conclusions and decisions based on the spreadsheets. With a view to systematically examining this problem via survey of existing work, we have conducted a comprehensive literature review on the quality issues and related techniques of spreadsheets over a 35.5-year period (from January 1987 to June 2022) for target journals and a 10.5-year period (from January 2012 to June 2022) for target conferences. Among other findings, two major ones are: (a) Spreadsheet quality is best addressed throughout the whole spreadsheet life cycle, rather than just focusing on a few specific stages of the life cycle. (b) Relatively more studies focus on spreadsheet testing and debugging (related to fault detection and removal) when compared with spreadsheet specification, modeling, and design (related to development). As prevention is better than cure, more research should be performed on the early stages of the spreadsheet life cycle. Enlightened by our comprehensive review, we have identified the major research gaps as well as highlighted key research directions for future work in the area.

Different testing techniques can be more or less effective on different fault types; therefore, testing methods that are most likely to detect the most common fault types should be preferred. However, to enable such a selection of testing methods, a suitable and effective fault classification scheme is essential. Much software testing research proposes techniques to generate test cases and evaluates these techniques based on some hypothesized fault classification scheme. However, there is a lack in the justification of whether such 'hypothesized faults' are realistic and how often these faults occur. Recently, Pan et al. analyzed the syntactic changes in the source code, made in fixing faults, of 7 open source software projects implemented in Java. Based on their experience, they proposed a fault classification scheme with relative frequencies of each fault type. As always, readers may question whether the resulting fault classification is reasonable and appropriate. Hence, we applied their method to Checkstyle, another open source Java program, as the subject of our study, hoping to validate the appropriateness of their fault classification scheme, with particular application for selecting testing methods. While we generally found their classification scheme reasonable, we also noted that some faults could be classified in multiple ways. We also found that the frequencies of fault categories in Checkstyle were significantly different to the seven systems studied by Pan et al., which had all shown to have quite similar frequencies. We identified several potential improvements to their classification, permitting the classification of a larger proportion of faults. We have identified new implications of the combined results for white-box testing, and proposed follow-up studies to examine these issues in more detail.