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31.
正现在的高收入人群觉得,随着收入和财富的增长而不断添置奢侈品是件没有必要的事情。这就是所谓的「后奢侈品时代」概念。奢侈品行业目前状态并不稳定;虽然有很多机会,但与此同时,也有许多能够威胁到行业增长的因素。专业服务公司德勤(Deloitte)在他们的《奢侈品的全球力量》研究中,强调了「奢侈品天启四骑士」的概念,即声誉风险、监管和利益相关者、外部事件以及惯性。这些研究都是有根据的,也肯定是值得参考的,它们反映了奢侈品行业的根本问题。这就跟鸵鸟受惊将头埋在沙里躲避危 相似文献
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BACKGROUND: Health care in Zimbabwe is provided by both orthodox and traditional care providers. With formal medical services under economic strain it is important to understand the extent of consulting with traditional care providers and their effectiveness. METHODS: A cross-sectional community survey recorded consultations and self-treatment for episodes of illness among 1251 individuals in 222 households randomly selected in two high-density suburbs of Harare, Zimbabwe. Three dependent variables (illness experience, consultation behaviour and choice of care provider) were analysed against a range of sociodemographic, episode-related and outcome measures. RESULTS: More than one-third of the sample had experienced an illness and 83% of these had led to consultation. Medical services were consulted eight times more often than traditional ones. Non-consulting behaviour was associated with lack of money or low perceived significance of problems. Physical problems were usually taken to medical clinics where their outcome was better, but non-specific pain and other problems did no better with medical or traditional care. CONCLUSIONS: While members of the community appear to recognize physical problems and take them to medical care, traditional and orthodox medical consultations appear to be equally effective for non-specific pain or non-specific physical problems. The role of traditional medicine in relation to non-specific physical problems and psychological problems is one which deserves further examination from both clinical and administrative perspectives. Poverty appears to be associated with poorer outcomes; this is a potentially important issue in times of increasing economic hardship. 相似文献
34.
Based on my experience as an engineer and educator, I believe that "engineering leadership" rather than "engineering management" should be the goal of engineers in key roles and the focus of their management education. I would also like to see programs in technical organizations led by engineering leaders rather than nontechnical managers. I believe that it is more beneficial to enhance the leadership potential of an engineer than to educate the nontechnical manager in technology. 相似文献
35.
KJ Dawson J Conaghan GR Ostera RM Winston K Hardy 《Canadian Metallurgical Quarterly》1995,10(1):177-182
Voluntary food intake, digestibility and water turnover were determined in adult Malaysian lesser mouse-deer (Tragulus javanicus) given unlimited access to lundai foliage (Sapium baccatum). Daily dry matter (DM) intake was 42.4 g/kg metabolic live mass (M0.73) or 3.7% M. Digestible energy intake was 853 kJ/day (571 kJ metabolisable energy per M0.73), calculated to be used with 79% efficiency. Apparent digestibility (%) of organic matter was 83.8, crude fibre 63.7, acid detergent fibre 60.5, neutral detergent fibre 72.1 and crude protein 65.0. Urinary excretion of the purine derivative, allantoin, was 0.05 mg/g digestible DM intake suggesting rumen microbial yield efficiency may be lower than in other ruminant species. Total water intake was 182 ml/M0.82. The body-water content of the fed mouse-deer, from tritiated water dilution, was 77% M, consistent with a very lean carcass. Turnover of body water was 17% per day. The mouse-deer produced relatively dry, well-defined faecal pellets. 相似文献
36.
Seah Winston Khoon‐Guan Takahashi Yutaka Hasegawa Toshiharu 《Telecommunication Systems》1998,10(3-4):243-268
In this paper, we analyse the message waiting times in a local area network (LAN) that uses the demand‐priority access method.
This is a priority‐based round‐robin arbitration method where the central controller (the repeater) polls its connected ports
to determine which have transmission requests pending and the requests' priority classes. We model it as a 2‐priority M/G/1 queue with multiple server vacations and switchover time between service periods. The service discipline is nonpreemptive
and the length of the switchover time is dependent upon the priority class of the preceding message served as well as that
of the message to be served next. We provide an approximate analysis for the waiting times of both message classes and derive
expressions for the Laplace–Stieltjes transforms (LST) of the stationary distributions and the mean waiting times. We conclude
with numerical and simulation results to show the applicability and accuracy of the analytical model.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
37.
Oladapo A. Afolabi M. O. Ologunde Winston A. Anderson John S. Read Michelle D. Dacosta Flavia A. Epps Folahan O. Ayorinde 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1991,51(1):41-46
Examined in this study is a potential application of Vernonia galamensis lipase (acetone powder) in enzyme-catalyzed hydrolysis of seed oils, most especially of those containing reactive functionalities which are easily affected under drastic hydrolytic and methylating/transesterification conditions during fatty acid analysis. Eight seed oils from V. galamensis, Ximenia kaffra, castor, corn, soyabean, palm kernel, sunflower and olive were hydrolyzed by lipase (acetone powder) followed by methylation using diazomethane in ethyl ether. Results obtained showed that the lipolytic hydrolysis of triglycerides by V. galamensis lipase (acetone powder) was probably nonspecific and did not result in isomerization and as such hydrolyzed the triglycerides of the seed oil in a fashion that the resulting fatty acids were unaltered during hydrolysis. The fatty acids obtained were representative of the parent seed oils. Values reported for the various seed oils were similar to those of previous studies. 相似文献
38.
We derive the theoretical upper limit for concentration of direct solar radiation at low latitudes with nontracking concentrators from the projected solid angle sampled by the apparent motion of the sun, for the case where the energy efficiency is referred to the energy incident on the entrance aperture. Based on the fact that the solar radiation is not uniformly distributed within this projected solid angle and that the apparent solar motion is known, we derive the optimal acceptance as a function of direction and time, which means rejecting the lower density radiation and switching off the device when losses would be higher than gains. Just as a device may gain concentration by rejecting radiation from certain directions, it can also gain by not operating at all, thus avoiding losses at certain times. Trough-type systems, which have translational symmetry, cannot be ideal nontracking concentrators, but for low losses they perform only slightly worse than general three-dimensional concentrators. 相似文献
39.
Energy consumption is a perennial issue in the design of wireless sensor networks (WSNs) which typically rely on portable sources like batteries for power. Recent advances in ambient energy harvesting technology have made it a potential and promising alternative source of energy for powering WSNs. By using energy harvesters with supercapacitors, WSNs are able to operate perpetually until hardware failure and in places where batteries are hard or impossible to replace. In this paper, we study the performance of different medium access control (MAC) schemes based on CSMA and polling techniques for WSNs which are solely powered by ambient energy harvesting using energy harvesters. We base the study on (i) network throughput (S), which is the rate of sensor data received by the sink, (ii) fairness index (F), which determines whether the bandwidth is allocated to each sensor node equally and (iii) inter-arrival time (γ) which measures the average time difference between two packets from a source node. For CSMA, we compare both the slotted and unslotted variants. For polling, we first consider identity polling. Then we design a probabilistic polling protocol that takes into account the unpredictability of the energy harvesting process to achieve good performance. Finally, we present an optimal polling MAC protocol to determine the theoretical maximum performance. We validate the analytical models using extensive simulations incorporating experimental results from the characterization of different types of energy harvesters. The performance results show that probabilistic polling achieves high throughput and fairness as well as low inter-arrival times. 相似文献
40.
Vitor R. ManfrinatoLin Lee Cheong Huigao DuanDonald Winston Henry I. SmithKarl K. Berggren 《Microelectronic Engineering》2011,88(10):3070-3074
We fabricated 9-30 nm half-pitch nested Ls and 13-15 nm half-pitch dot arrays, using 2 keV electron-beam lithography with hydrogen silsesquioxane (HSQ) as the resist. All structures with 15 nm half-pitch and above were fully resolved. We observed that the 9 and 10-nm half-pitch nested Ls and the 13-nm-half-pitch dot array contained some resist residues. We obtained good agreement between experimental and Monte-Carlo-simulated point-spread functions at energies of 1.5, 2, and 3 keV. The long-range proximity effect was minimal, as indicated by simulated and patterned 30 nm holes in negative-tone resist. 相似文献