Jack of all trades

A second possibility is to use some estimate of the variance of the loadings. This can be done by the jackknife method due to Quenouille and Tukey (see [37]) or by Efron s bootstrap method [38] (the colourful terminology stems from the expressions jack of all trades and master of none and lifting yourself up by your own bootstraps ). The use of the bootstrap to estimate the variance of the loadings in PCA has been described [39] and will not be elaborated upon further. The jackknife method is used partly because it is a natural side-product of the cross-validation and therefore computationally non-demanding and partly because the jackknife estimate of variance is used later on in conjunction with PLS. 

Historically, the major players in the industry have been jacks-of-all-trades. Integrated businesses in which a single company controlled the entire process - from the supply of raw materials to the outlets for its products - were the norm. Because of the development of individual national markets and the lack of a significant pipeline infrastructure, Europe became even more integrated than North America. 

An indication of the kinds of improvisations both tolerated and required may be inferred from an astute case study of two East German factories before the Wall came down in 1989. Each factory was under great pressure to meet production quotas—on which their all-important bonuses depended—in spite of old machinery, inferior raw materials, and a lack of spare parts. Under these draconian conditions, two employees were indispensable to the firm, despite their modest place in the official hierarchy. One was the jack-of-all-trades who improvised short-term solutions to keep machinery running, to correct or disguise production flaws, and to make raw materials stretch further. The second was a wheeler-dealer who located and bought or bartered for spare parts, machinery, and raw material that could not be obtained through official channels in time. To facilitate the wheeler-dealer s... 

Don t put all your eggs in one basket. This advice for portfolio diversification may be contrasted with the advice suggested by the phrase Jack of all trades and master of none, that is, that one should invest heavily in one line of activity rather than spread oneself thinly over many. In situations that are characterized both by risk aversion and increasing marginal returns, either advice might trigger the decision.31... 

By Vitruvius s definition, an architect needs to be the master of everything or jack of all trades. It might have been possible then for one person to master the multiple disciplines of art, science, and engineering such as literature, mathematics, history, philosophy, music, medicine, and astronomy, as we assume those disciplines during those days were at a rather superficial level. But with advancement of science and technology, it is not possible for one person to master the multiple disciplines of art, science and engineering. It should be noted that there are more scientists alive today that all of the scientists ever lived in the history of mankind ... 

Black powder (gun powder), the jack-of-all-trades of the older fireworks art, is characterized by versatility, low cost, easy ignitibility, excellent fire transfer properties at a wide range of temperatures and... 

Szilard promised to write Wigner again when he had an actual program. He did not yet know that his actual program would be organizing the desperate rescue. He parked his bags at the Harnack House in Dahlem and sat down with Lise Meitner to talk about doing nuclear physics at the Kaiser Wilhelm Institute. She had Hahn, and Hahn was superb, but he was a chemist. She could use a jack-of-all-trades tike Szilard. But the collaboration was not to be. Events moved too quickly. Szilard took his train from Berlin, the train that proved him, if not more clever than most people, at least a day earlier. That was close to the first of April, 1933. ... 

I started in a company where everything was decentralized. We were like cowboys roaming the earth. I think we realized that we were a jack-of-all-trades and masters of none. 

A transitory career is just that—transitioning from one experience to another so frequently that it may not seem as if a person settles down long enough to actually have a career - at least in the traditional sense. Jack of all trades would aptly describe the person with such a career [8]. 

There is a perception in the motor carrier industry regarding the safety position — that it s a role that requires an individual to wear many hats (see Defining the Role tab). Because of this, the t5q)ical safety manager is a kind of jack-of-all-trades, and master of only a few. 

There are many different aspects to system safety that must be considered when conducting a system safety program (SSP). The primary tasks of a SSP are to identify hazards and mitigate them to an acceptable level of risk. However, there are many secondary SSP tasks that must be performed, such as supporting the special safety requirements in the specialized areas of safety (e.g., laser safety, explosives safety, fire safety, battery safety).The system safety engineer is truly a systems engineer, and a jack-of-all-trades, who must be familiar with all aspects of the system involved, as well as all aspects of safety applicable to the system. 

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