Growth of Incumbent Firms and Entrepreneurship in Vietnam

This paper analyzes the relationship between the performance of incumbent firms and the net entry of new firms by combining different theoretical views of entrepreneurship. It shows that new knowledge and ideas created but not commercialized by incumbents are an important source of entrepreneurial opportunities for nascent firms. Different regression models to treat dynamics and endogeneity issues are applied to test the research hypothesis that growth of incumbent firms in a region will stimulate start-up activities by creating new profit opportunities for potential entrepreneurs. Vietnam’s regional micro-data from 2000 to 2008 are used for this test. Four controlling indicators – entrepreneurial demand, market structure, regional economic environment, and market innovativeness – are found to exert a statistically significant effect on new entries.

The Interplay of Human and Social Capital in Shaping Entrepreneurial Performance: The Case of Vietnam

This study investigates the effects of human capital, social capital and their interaction on the performance of 1,398 Vietnamese new-born firms. Operating profit is used as the measure of success. Human capital is captured by individual-level professional education, start-up experience, and learning. Whereas the first two dimensions of human capital are measured with traditional indicators, we define learning as ability to accumulate knowledge to conduct innovation activities (new product introduction, product innovation and process innovation). Social capital is measured as benefits obtained from personal strong-tie and weak-tie networks. Key findings are three-fold: (i) human capital strongly predicts firm success, with learning exerting a statistically significant positive impact on operating profit; (ii) benefits from weak ties outweigh those from strong ties; (iii) interaction of human capital and social capital displays a statistically significant positive effect on new-firm performance.

Motives for investment in human capital of children: evidence from Indonesian Family Life Survey Data

Two alternative models of parental investments in children's human capital are considered and tested empirically using the Indonesian Family Life Survey (IFLS). The pure loan model and the reciprocity with two-sided altruism model yield different predictions about the effect of children's education level and number of children on intergenerational transfers. Using these predictions, a specification test is carried out to differentiate these two models with the data. The evidence favors the second model of reciprocity with two-sided altruism.Human capital, pure loan, altruism, Indonesian Family Life Survey Data

Effects of chemical equilibrium on turbine engine performance for various fuels and combustor temperatures

A study was performed to quantify the differences in turbine engine performance with and without the chemical dissociation effects for various fuel types over a range of combustor temperatures. Both turbojet and turbofan engines were studied with hydrocarbon fuels and cryogenic, nonhydrocarbon fuels. Results of the study indicate that accuracy of engine performance decreases when nonhydrocarbon fuels are used, especially at high temperatures where chemical dissociation becomes more significant. For instance, the deviation in net thrust for liquid hydrogen fuel can become as high as 20 percent at 4160 R. This study reveals that computer central processing unit (CPU) time increases significantly when dissociation effects are included in the cycle analysis

SWIPT-based cooperative NOMA for two-way relay communications: PSR versus TSR

Spectrum and energy efficiency with simultaneous wireless information and power transfer (SWIPT) to prolong the lifetime of power-constrained wireless devices in cooperative relaying nonorthogonal multiple access (CR-NOMA) has received great attention in the last decade. This paper investigates a two-way relay channel in a CR-NOMA system where two users exchange data with the assistance of a relay. Power-splitting relaying (PSR) and time-switching relaying (TSR) protocols are employed at the relay to harvest RF energy and process information from two users. We firstly derive the exact expressions of outage probability (OP) and system throughput (ST). The impacts of signal quality, energy coefficients, the distance of the nodes, and the data rate of two users on these performance metrics are then evaluated through several system settings to reflect practical network scenarios. It is shown that the OP and ST of the TSR are superior to that of the PSR protocol. Specifically, numerical results indicate that a higher throughput of up to 8% can be achieved with the TSR when compared to the PSR. It is further revealed that the OP and ST of the PSR are strongly affected by energy harvesting (EH) coefficients, while the performance obtained with the TSR is nearly independent of the EH capability at the relay

Strength and flexibility properties of advanced ceramic fabrics

The mechanical properties of four advanced ceramic fabrics are measured at a temperature range of 23 C to 1200 C. The fabrics evaluated are silica, high-and low-boria content aluminoborosilicate, and silicon carbide. Properties studied include fabric break strengths from room temperature to 1200 C, and bending durability after temperature conditioning at 1200 C and 1400 C. The interaction of the fabric and ceramic insulation is also studied for shrinkage, appearance, bend resistance, and fabric-to-insulation bonding. Based on these tests, the low-boria content aluminoborosilicate fabric retains more strength and fabric durability than the other fabrics studied at high temperature