1,989 research outputs found
A general framework for the realistic analysis of sorting and searching algorithms. Application to some popular algorithms
We describe a general framework for realistic analysis of sorting and searching algorithms, and we apply it to the average-case analysis of five basic algorithms: three sorting algorithms (QuickSort, InsertionSort, BubbleSort) and two selection algorithms (QuickMin and SelectionMin). Usually, the analysis deals with the mean number of key comparisons, but, here, we view keys as words produced by the same source, which are compared via their symbols in the lexicographic order. The "realistic" cost of the algorithm is now the total number of symbol comparisons performed by the algorithm, and, in this context, the average-case analysis aims to providee stimates for the mean number of symbol comparisons used by the algorithm. For sorting algorithms, and with respect to key comparisons, the average-case complexity of QuickSort is asymptotic to 2n log n, InsertionSort to n^2/4 and BubbleSort to n^2/2. With respect to symbol comparisons, we prove that their average-case complexity becomes Theta(n log^2n), Theta(n^2), Theta (n^2 log n). For selection algorithms, and with respect to key comparisons, the average-case complexity of QuickMin is asymptotic to 2n, of SelectionMin is n - 1. With respect to symbol comparisons, we prove that their average-case complexity remains Theta(n). In these five cases, we describe the dominant constants which exhibit the probabilistic behaviour of the source (namely, entropy, and various notions of coincidence) with respect to the algorithm
APPLICATION OF THE MODEL 5E TO DESIGN A TEACHING PLAN FOR THE TOPIC “WHAT ARE THE CHARACTERISTICS OF WATER?” IN 4TH GRADE SCIENCE SUBJECT OF VIETNAM IN STEM EDUCATIONAL ORIENTATION
STEM education is an educational model based on the interdisciplinary integration of science, technology, engineering and mathematics to solve real-life problems (Bentley et al., 2022; Kaleci & Korkmaz, 2018). When implementing STEM education in primary schools, there are many different approaches: discovery model, engineering design model, 5E, 6E, TRIAL model (Chacko et al., 2015; Kaleci & Korkmaz, 2018; Matsuura & Nakamura, 2021; Stohlmann et al., 2012). The selection of a model to apply appropriately is important, depending on the student, the actual teaching conditions, the teaching content, etc. The article analyzes the content of Science in primary school, teaching practice in Vietnam and illustrates the design of a specific teaching plan for grade 4 students on the basis of applying the model 5E to organize STEM education-oriented teaching in order to provide teachers with an approach when designing science teaching plans for primary school students. Article visualizations
Incentives and Firm Behaviors
My research interests focus on the economic behavior, choices, and actions of organizations as well as individuals given their incentives, and analyze the consequences of such decisions to the financial health of firms and the macro economy. A firm is incentivized by the value investors place on its operations; while employees, particularly the management team, is incentivized by the private benefits the firm gives them. Understanding the impact of such incentives will help alleviate the classic agency costs in modern organizations.
Stock illiquidity raises the cost of share ownership to outside investors. The sizable adverse price impact of trading increases transactions costs and stock volatility. The reduced gains from informed trading discourages the acquisition of private information and impedes the price discovery process. The first essay substantiates that shares of financially constrained firms are significantly more illiquid than shares of similar but financially unconstrained firms. Acting as buyers of last resort for their own shares, share repurchases by financially constrained firms enhance stock liquidity, which alleviates the cost of external financing and underinvestment. Increased stock liquidity improves information efficiency, inducing higher value-added from incremental capital investments. Further, higher stock liquidity lowers stock volatility and allows financially constrained firms to issue equity.
In the second and third essays, I investigate whether the incentives given to the employees and the management team at banks contribute to the financial crisis. I provide evidence that CEO compensation is weakly related to bank risk measures and risky bank activities. However, when looking at banks with regards to their reward cultures, I find that during the 2008 crisis period, banks either at the high or low reward culture groups perform worse, and are more risky than banks in the average reward culture group. The reward culture score represents the common factor in incentives across all levels of the bank, from CEO, Vice Presidents to all other employees. The findings are consistent with the problems of adverse selection and moral hazard associated with incentive misalignment when incentives are too low or too high. This shows the importance of reward culture in understanding the role of performance-based compensation
CRACKING CORROSION OF LOW CARBON STEEL IN ENVIRONMENT WITH A HIGH CONCENTRATION OF CO2 AND H2S
Cracking corrosion of API 5CT Grade L80 Type 1 low carbon steel has been studied in a in brine solutions with H2S 12.3 psia and CO2 9.4 psia. Testing was performed according to the methodology reference from the NACE TM0177, Bent-beam test method in solution B for stress corrosion cracking and sulfide stress corrosion cracking test and NACE TM0284, immersion test method in solution A for Hydrogen induced cracking test.The obtained results showed pitting and general corrosion at both temperatures of 24 oC and 82 oC. In case of stress corrosion cracking (SCC) testing at 82 °C, microscopy of the samples tested for 30 days developed pitting corrosion in the surface and cracking starting in the surface of the samples. The cracks, mostly found in the middle of the samples where the maximum bending occurred. General corrosion was also observed in the samples, with significant decrease in the dimensions of the samples after testing (due to general corrosion). However, in case of sulfide stress corrosion (SSC) and hydrogen induced cracking (HIC) tests at room temperature (24-25 oC), no cracking was observed on the sample.
Consequences of urban migration of adult children for the elderly left-behind in rural Vietnam
Following market liberalisation in Vietnam, concern has been raised about the elderly ‘left behind’ by the urban migration of adult children from rural areas. This study used qualitative methods to examine the consequences for these elderly and the strategies they adopt to cope. It found overall positive outcomes for rural aged parents with migrant children, as long as at least one family member remained nearby. However, elderly with no remaining family members suffered more
Models of residential space for ethnic minorities in Thanh Hoa Province associated with sustainable livelihoods
Thanh Hoa Province has 11 mountainous districts with seven ethnic minority groups, and the three largest ethnic groups are the Muong, Thai, and H'Mong. This region has great potential for developing a forest-based economy, ecotourism, community-based tourism, and cultural heritage tourism that is associated with cultural festivals, customs, lifestyles, and traditional housing architecture. However, developing a family-based economy, such as engaging in community-based tourism or agricultural production, has negatively affected and disrupted the structure of village spaces, spatial planning, and traditional house design. The arbitrary construction of additional service spaces and spaces for resident guests within the village space and the precinct of a house has reduced the area of the garden and agricultural land. The self-initiated modification, expansion, and use of non-traditional materials in traditional housing structures by residents to serve tourists have resulted in the loss of the architectural value of traditional homes. The exploitation of agricultural land has affected the natural forest area, the forest protection area at the headwaters, and the vegetation cover and natural ecosystems. Moreover, agricultural economic activities have not been linked to service activities, handicraft production, or tourism, and there are no adaptive residential space models, thus failing to create sustainable livelihood activities. Therefore, the article proposes settlement space models and orientations for residential space development including village spaces, house precincts, and traditional housing spaces of ethnic minorities in Thanh Hoa Province, associated with sustainable livelihoods based on the exploitation of traditional housing architectural heritage values to ensure local economic development. These models are closely linked with the conservation and promotion of ethnic cultural values, landscape preservation, environmental protection, and contribution to poverty reduction for residents
Vitamin C inhibited FasL-induced apoptotic death of mouse dendritic cells through c-FLIP expression
Vitamin C (VitC) is a potent antioxidant and contributes as an apoptosis inhibitor by preventing death receptor-triggered caspase 8 activity. Fas ligand (FasL) induces the apoptotic cell death via activation of Fas signaling, which is dependent on the expression level of anti-apoptotic molecule c-FLIP (FADD-like IL-1beta-converting enzyme-inhibitory proteins). The present study addressed the effects of VitC on survival of dendritic cells (DCs), a regulator of innate and adaptive immunity. To this end, mouse bone marrow cells were isolated and cultured to attain bone marrow-derived DCs (BMDCs). The cells were treated with FasL in the presence or absence of VitC. Real time RT-PCR, Western blotting and FACS analysis were performed to determine different hallmarks of DC apoptosis. As a result, FasL treatment resulted in activation of caspase 8 and stimulation of cell membrane scrambling, the effects were supressed when VitC was present in the cell culture or the cells were transfected with FLIP siRNA. In conclusion, VitC prevented FasL-triggered DC apoptosis mediated through the expression of c-FLIP
THE RELAXATION SPEED IN THE CASE THE FLOW SATISFIES EXPONENTIAL DECAY OF CORRELATIONS
We study the convergence speed in L 2-norm of the diffusion semi-group toward its equilibrium when the underlying flow satisfies decay of correlation. Our result is some extension of the main theorem given by Constantin, Kiselev, Ryzhik and Zlatoš in [3]. Our proof is based on Weyl asymptotic law for the eigenvalues of the Laplace operator, Sobolev imbedding and some assumption on decay of correlation for the underlying flow
Conceptual Metaphor of Different Conventionality Levels from the Perspectives of Translatability Assessment and Translation Strategies
This study examines the Conceptual Metaphor Theory from an innovative perspective: translatability and translation strategy. The experiment recruited 239 undergraduate students of different translation training to evaluate the translatability of twelve sentences of different metaphor types before translating them into Vietnamese. Additionally, this study examines how students deal with metaphorical mapping images as well as grammatical and lexical refining attempts. The factorial ANOVA results (p=.02) indicate that the effect of metaphor types on translatability levels is conditional on translation training levels, despite the fact that the main effect is on metaphor types, not translation skill. Besides, twelve in-depth strategies to deal with the source sentences are identified, establishing a new model for metaphorical translation strategy. Chi-square analysis reveals associations between translation training levels and strategies (p<.01); and between metaphor types and strategies (p<.01). This study argues for the possibility that translation could be considered among conceptual metaphor's cognitive mechanisms
Expression, purification and evaluation of recombinant L-asparaginase inmehthylotrophic yeast Pichia pastoris: Expression, purification and evaluation of recombinant L-asparaginase in mehthylotrophic yeast Pichia pastoris: Research article
L-asparaginase (EC 3.5.1.1), a therapeutic enzyme used in the treatment of childhood acute lymphoblastic leukemia (ALL). Hence, the goal of this work is study the expression and evaluation of hydrolysis activity of native sequence (X12746) encoding for L-asparaginase from Erwinia chrysanthemi NCPBB1125 in the popular expression system Pichia pastoris. The sequence of asn encoded for mature protein was expressed in P. pastoris SMD1168 and X33. SDS-PAGE analysis showed recombinant L-asparaginase was secreted efficiently. Stable and high hydrolysis activity of extracellular L-asparaginase in P. pastoris SMD1168 making it a potential candidate to produce recombinant protein. After purification, a specific band whose appearance approximately 45 kDa indicating the glycosylated protein with specific activity by 6.251 Umg-1 and about 3 folds purifications.L-asparaginase (EC 3.5.1.1), một loại enzyme được sử dụng trong điều trị bệng ung thư bạch cầu mãn tính ở trẻ em. Mục tiêu của nghiên cứu này là biểu hiện và đánh giá hoạt tính thủy phân của L-asparaginase mã hóa bởi đoạn gene (X12746) tương ứng từ Erwinia chrysanthemi NCPBB1125 được biểu hiện trong nấm men Pichia pastoris. Gene đã được cắt signal peptide và biểu hiện trong P. pastoris SMD1168 and X33. Qua phân tích kết quả điện di SDS-PAGE của môi trường sau lên men, L-asparaginase tái tổ hợp được tìm thấy trong dịch ngoại bào của P. pastoris. Với khả năng sản xuất protein có hoạt tính cao hơn so với chủng P. pastoris X33, SMD1168 được lựa chọn để biểu hiện L-asparaginase tái tổ hợp. Sau khi tinh sạch, sự xuất hiện của một băng có kích khối lượng phân tử xấp xỉ 45 kDa trên điện di SDS-PAGE cho thấy protein tái tổ hợp đã bị glycosyl hóa với hoạt tính riêng 6.251 Umg-1 và đạt độ sạch 3.471 lần
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