Capital Budgeting Evaluation Practices of Building Contractors in Hong Kong

This paper reports the results of an investigation into capital budgeting evaluation practicesin the construction industry of Hong Kong. The aim of this study was to identify thepopularity and extent of usage of various techniques for capital budget evaluation, investmentappraisal, risk analysis, and management science. The current study was comparedwith a similar survey conducted in 1994 to establish the changes in the capital budgetingevaluation practices of contracting firms over time. The results indicate that there was ageneral increase in the popularity and extent of usage in certain capital budget evaluationtechniques such as “best/worst estimate” and “formal financial evaluation”. In addition,the evaluation techniques examined were fitted into a discriminant function analysis (DFA),and a model has been developed which allows contracting firms to be classified accordingto their predominant characteristics in capital budget evaluation

Precise-Spike-Driven synaptic plasticity: Learning hetero-association of spatiotemporal spike patterns

10.1371/journal.pone.0078318PLoS ONE811-POLN

Domestic Value Added and Employment Generated by Chinese Exports: A Quantitative Estimation

We develop an input-output methodology to estimate how Chinese exports affect the country’s total domestic value added (DVA) and employment for 1995 and 2002. Total DVA generated by exports is obtained by subtracting all direct and indirect imported intermediate goods from the gross value of exports, and total employment is obtained by adding all direct and indirect employment generated by exports. To implement these estimations, we use hitherto unpublished Chinese government data to construct several completely new datasets, including an input-output table with separate input-output and employment-output coefficients for processing and non-processing exports. In 2002 (1995), for every US$1,000 dollar of Chinese exports, DVA and employment are estimated to be US$466 (US$545) and 0.242 (0.375) person-year, respectively.Input-output tables, Chinese exports, employment, domestic value added

Intracranial Metastatic Melanoma

Central nervous system (CNS) metastases are a common manifestation of malignant melanoma, with a median overall survival of as little as 4.7 months based on a study of patients diagnosed between 1986 and 2004 prior to the era of effective systemic therapy. Yet most of the clinical trials exclude patients with intra-cranial metastases. CNS involvement often causes neurological deficits and functional impairment. Localised therapies, such as surgical excision and stereotactic radiotherapy are applicable to only a minority of patients. There are evidences of clinical benefits for immunotherapy than best supportive care and when given alongside radiotherapy provides a better overall survival than radiotherapy alone. This chapter evaluates the efficacy and toxicity of these treatments against advanced melanoma patients with brain metastases

Boron Fullerenes: A First-Principles Study

A family of unusually stable boron cages was identified and examined using first-principles local density functional method. The structure of the fullerenes is similar to that of the B12 icosahedron and consists of six crossing double-rings. The energetically most stable fullerene is made up of 180 boron atoms. A connection between the fullerene family and its precursors, boron sheets, is made. We show that the most stable boron sheets are not necessarily precursors of very stable boron cages. Our finding is a step forward in the understanding of the structure of the recently produced boron nanotubes.Comment: 10 pages, 4 figures, 1 tabl

Scanning acoustic microscopy investigation of engineered flip-chip delamination

The rapid uptake of flip-chip technology within the electronics industry, is placing the reliability of such assemblies under increasing scrutiny. A key feature of the assembly process is the application of underfill to reinforce the attachment of the die to the printed circuit board. This has been identified in numerous studies as one of the major ways in which the reliability of the devices can be improved, by mitigating the coefficient of thermal expansion mismatch between chip and board. However, in order for the underfill to be effective in coupling the die to the circuit board, its adhesion to the passivation layer of the die and the solder mask layer on the PCB must be maximised. There is a growing body of literature that indicates that poor adhesion at either interface (delamination) as a result of contamination can result in premature failure of the assembly through stress fracture of the solder joints. In order to investigate further the effect of delamination on the reliability of flip-chip assemblies, surface chemistry has been used to control the adhesion of the underfill to the die passivation. This paper reports how modification of the die surface by the application of a low surface energy coating, which prevents the strong adhesion of the underfill, has enabled the selective delamination of the device at the chip-to-underfill interface. Using scanning acoustic microscopy (SAM) the effectiveness of this treatment in creating controlled delamination before and after thermal cycling has been monitored. The ability to engineer delamination, can enable experimental studies of the mechanics of flip chip assembly failure, which complement current finite element modelling work

High temporal resolution modelling of environmentally-dependent seabird ammonia emissions: description and testing of the GUANO model

Many studies in recent years have highlighted the ecological implications of adding reactive nitrogen (Nr) to terrestrial ecosystems. Seabird colonies represent a situation with concentrated sources of Nr, through excreted and accumulated guano, often occurring in otherwise nutrient-poor areas. To date, there has been little attention given to modelling N flows in this context, and particularly to quantifying the relationship between ammonia (NH3) emissions and meteorology. This paper presents a dynamic mass-flow model (GUANO) that simulates temporal variations in NH3 emissions from seabird guano. While the focus is on NH3 emissions, the model necessarily also treats the interaction with wash-off as far as this affects NH3. The model is validated using NH3 emissions measurements from seabird colonies across a range of climates, from sub-polar to tropical. In simulations for hourly time-resolved data, the model is able to capture the observed dependence of NH3 emission on environmental variables. With temperature and wind speed having the greatest effects on emission for the cases considered. In comparison with empirical data, the percentage of excreted nitrogen that volatilizes as NH3 is found to range from 2% to 67% (based on measurements), with the GUANO model providing a range of 2%–82%. The model provides a tool that can be used to investigate the meteorological dependence of NH3 emissions from seabird guano and provides a starting point to refine models of NH3 emissions from other sources

Domestic Value Added and Employment Generated by Chinese Exports: A Quantitative Estimation

We develop an input-output methodology to estimate how Chinese exports affect the country’s total domestic value added (DVA) and employment for 1995 and 2002. Total DVA generated by exports is obtained by subtracting all direct and indirect imported intermediate goods from the gross value of exports, and total employment is obtained by adding all direct and indirect employment generated by exports. To implement these estimations, we use hitherto unpublished Chinese government data to construct several completely new datasets, including an input-output table with separate input-output and employment-output coefficients for processing and non-processing exports. In 2002 (1995), for every US$1,000 dollar of Chinese exports, DVA and employment are estimated to be US$466 (US$545) and 0.242 (0.375) person-year, respectively

A quasar discovered at redshift 6.6 from Pan-STARRS1

Luminous high-redshift quasars can be used to probe of the intergalactic medium in the early universe because their UV light is absorbed by the neutral hydrogen along the line of sight. They help us to measure the neutral hydrogen fraction of the high-z universe, shedding light on the end of reionization epoch. In this paper, we present a discovery of a new quasar (PSO J006.1240+39.2219) at redshift z = 6.61 ± 0.02 from Panoramic Survey Telescope & Rapid Response System 1. Including this quasar, there are nine quasars above z > 6.5 up to date. The estimated continuum brightness is M1450 = -25.96 ± 0.08. PSO J006.1240+39.2219 has a strong Ly α emission compared with typical low-redshift quasars, but the measured near-zone region size is RNZ = 3.2 ± 1.1 proper megaparsecs, which is consistent with other quasars at z ∼ 6

Measurement of the Atmospheric Muon Spectrum from 20 to 3000 GeV

The absolute muon flux between 20 GeV and 3000 GeV is measured with the L3 magnetic muon spectrometer for zenith angles ranging from 0 degree to 58 degree. Due to the large exposure of about 150 m2 sr d, and the excellent momentum resolution of the L3 muon chambers, a precision of 2.3 % at 150 GeV in the vertical direction is achieved. The ratio of positive to negative muons is studied between 20 GeV and 500 GeV, and the average vertical muon charge ratio is found to be 1.285 +- 0.003 (stat.) +- 0.019 (syst.).Comment: Total 32 pages, 9Figure