题目内容

People do not have secret trolleys at the supermarket, so how can it be a violation of their privacy if a grocer sells their purchasing habits to a marketing firm If they walk around in public view, what harm can cameras recording their movements cause A company is paying them to do a job, so why should it not read their e-mails when they are at work How, what and why, indeed. Yet, in all these situations, most people feel a sense of unease. The technology for gathering, storing, manipulating and sharing information has become part of the scenery, but there is little guidance on how to resolve the conflicts created by all the personal data now washing around. "Contravene" in the third paragraph is closest in meaning to [A] violated. [B] renounced. [C] conceded. [D] released.

A group of computer scientists at Stanford University, led by John. Mitchell, has started to address the problem in a novel way. Instead of relying on rigid (and easily programmable) codes of what is and is not acceptable, Dr. Mitchell and his colleagues Adam Barth and Anupam Datta have turned to a philosophical theory called contextual integrity. This theory acknowledges that people do not require complete privacy. They will happily share information with others as long as certain social norms are met. Only when these norms are contravened--for example, when your psychiatrist tells the personnel department all about your consultation--has your privacy been invaded. The team think contextual integrity can be used to express the conventions and laws surrounding privacy in the formal vernacular of a computer language.
B. Contextual integrity, which was developed by Helen Nissenbaum of New York University, relies on four classes of variable. These are the context of a flow of information, the capacities in which the individuals sending and receiving the information are acting, the types of information involved, and what she calls the "principle of transmission".
C. It is the fourth of these variables that describes the basis on which information flows. Someone might, for example, receive information under the terms of a commercial exchange, or because he deserves it, or because someone chose to share it with him, or because it came to him as a legal right, or because he promised to keep it secret. These are all examples of transmission principles.
Dr. Nissenbaum has been working with Mr. Barth to turn these wordy descriptions of the variables of contextual integrity into formal expressions that can be incorporated into computer programs. The tool Mr. Barth is employing to effect this transition is linear temporal logic, a system of mathematical logic that can express detailed constraints on the past and the future.
E. Linear temporal logic is an established discipline. It is, for example, used to test safety critical systems, such as aeroplane flight controls. The main difference between computer programs based on linear temporal logic and those using other sorts of programming language is that the former describe how the world ought to be, whereas the latter list specific instructions for the computer to carry out in order to achieve a particular end. The former say something like: "If you need milk, you ought eventually to arrive at the shop. "The latter might say: "Check the refrigerator. If there is no milk, get in your car. Start driving. Turn left at the corner. Park. Walk into the shop."
F. Dr. Mitchell and his team have already written logical formulae that they believe express a number of American privacy laws, including those covering health care, financial institutions and children’s activities online. The principles of transmission can be expressed in logical terms by using concepts such as "previously" and "eventually" as a type of mathematical operator. (They are thus acting as the equivalents of the "plus", "minus", " multiply" and "divide" signs in that more familiar system of logic known as arithmetic.) For example, the Gramm-Leaeh-Bliley act states that "a financial institution may not disclose personal information, unless such financial institution provides or has provided to the consumer a notice. "This is expressed as:
G. IF send (financial-institution, third-party, personal-information)
H. THEN PREVIOUSLY send (financial-institution, consumer, notification)
I. OR EVENTUALLY send (financial-institution, consumer, notification)According to Dr. Nissenbaum, applying contextual integrity to questions of privacy not only results in better handling of those questions, but also helps to pinpoint why new methods of gathering information provoke indignation. In a world where the ability to handle data is rapidly outpacing agreement about how that ability should be used, this alone is surely reason to study it.

查看答案

搜索结果不匹配？点我反馈

更多问题

代理记账，是指企业委托有会计资格证书的人员的记账行为。（）

A. 对
B. 错

查看答案

Fish farming in the desert may at first sound like an anomaly, but in Israel over the last decade a scientific hunch has turned into a bustling business. Scientists here say they realized they were no to something when they found that brackish water drilled from underground desert aquifers (含土水层) hundreds of feet deep could be used to raise warm-water fish. The geothermal water, less than one-tenth as saline as sea water, free of pollutants and a toasty 98 degrees on average, proved an ideal match. "It was not simple to convince people that growing fish in the desert makes sense," said Samuel Appelbaum, a professor and fish biologist at the Jacob Blaustein Institutes for Desert Research at the Sede Boqer campus of Ben-Gurion University of the Negev. "It is important to stop with the reputation that arid land is nonfertile, useless land," said Professor Appelbaum, who pioneered the concept of desert aquaculture in Israel in the late 1980s. "We should consider arid land where subsurface water exists as land that has great opportunities, especially in food production because of the low level of competition on the land itself and because it gives opportunities to its inhabitants." The next step in this country, where water is scarce and expensive, was to show farmers that they could later use the water in which the fish are raised to irrigate their crops in a system called double usage. The organic waste produced by the cultured fish makes the water especially useful, because it acts as fertilizer for the crops. Fields watered by brackish water dot Israel’s Negev and Arava Deserts in the south of the country, where they spread out like green blankets against a landscape of sand dunes and rocky outcrops. At Kibbutz Mashabbe Sade in the Negev, the recycled water from the fish ponds is used to irrigate acres of olive and jojoba groves. Elsewhere it is also used for irrigating date palms and alfalfa. The chain of multiple users for the water is potentially a model that can be copied, especially in arid third world countries where farmers struggle to produce crops, and Israeli scientists have recently been peddling their ideas abroad. Dry lands cover about 40 percent of the planet, and the people who live on them are often among the poorest in the world. Scientists are working to share the desert aquaculture technology they fine-turned here with Tanzania, India, Australia and China, among others. (Similar methods offish farming are being used in the Sonoran Desert of Arizona.) "Each farm could run itself, which is important in the developing world," said Alon Tal, a leading Israeli environmental activist who recently organized a conference on desertification, with the United Nations Convention to Combat Desertification and Ben-Gurion University, that brought policy makers and scientists from 30 countries to Israel. "A whole village could adopt such a system," Dr. Tal added. At the conference, Gregoire de Kalbermatten, deputy secretary general of the antidesertification group at the United Nations, said, "We need to learn from the resilience of Israel in developing dry lands." Israel, long heralded for its agricultural success in the desert through innovative technologies like drip irrigation, has found ways to use low-quality water and what is considered terrible soil to grow produce like sweet cherry tomatoes, people, asparagus and melon, marketing much of it abroad to Europe, especially during winter. The history of fish-farming in nondesert areas here, mostly in the Galilee region near the sea, dates back to the late 1920s, before Israel was established as a state. At the time, the country was extremely poor and meat was considered a luxury. But fish was a cheap food source, so fish farms were set up on several kibbutzim in the Galilee. The early Jewish farmers were mostly Eastern Europeans, and Professor Safriel said, "they only knew gefilte fish, so they grew carp." Eventually they expanded to other varieties of fish including tilapia, striped bass and mullet, as well as ornamental fish. The past decade has seen the establishment of about 15 fish farms producing both edible and ornamental fish in the Negev and Arava Deserts. Fish farming, meanwhile, has became more lucrative worldwide as people seek more fish in their diet for better health, and ocean fisheries increasingly are being depleted. The practice is not without critics, who say it can harm the environment and the fish. In Israel there was a decision by the government to stop fish fanning in the Red Sea near the southern city of Eilat by 2008 because it was deemed damaging to nearby coral reefs. Some also argue that the industry is not sustainable in the long term because most of the fish that are fanned are carnivorous and must be fed a protein-rich diet of other fish, usually caught in the wild. Another criticism is that large numbers of fish are kept in relatively small areas, leading to a higher risk of disease. Professor Appelbaum said the controversy surrounding fish farming in ocean areas does not apply to desert aquaculture, which is in an isolated, controlled area, with much less competition for resources. According to Uriel Safriel, what is the important force that drivers Israeli scientists to develop desert aquiculture as well as agriculture technologies

A. The fact that Israel is a country where fresh water is scarce and valuable.
B. The fact that Israelis are forced to wring food from arid lands.
C. The Israeli determination to reconstruct their country.
D. The Hebrew belief that desert is a reconstruct their country.

查看答案

The world seems increasingly divided into those who favor genetically modified (GM) foods and those who fear them. Advocates assert that growing genetically altered crops can be kinder to the environment and that eating foods from those plants is perfectly safe. And, they say, genetic engineering—which can induce plants to grow in poor soils or to produce more nutritious foods—will soon become an essential tool for helping to feed the world’s burgeoning population. Skeptics contend that GM crops could pose unique risks to the environment and to health—risks too troubling to accept placidly. Taking that view, many European countries are restricting the planting and importation of GM agricultural products. Much of the debate hinges on perceptions of safety. But what exactly does recent scientific research say about the hazards Advocates of GM, or transgenic, crops say the plants will benefit the environment by requiring fewer toxic pesticides than conventional crops. But critics fear the potential risks and wonder how big the benefits really are. "We have so many questions about these plants," remarks Guenther Stotzky, a soil microbiologist at New York University. "There’s a lot we don’t know and need to find out. " As GM crops multiply in the landscape, unprecedented numbers of researchers have started fanning into the fields to get the missing information. Some of their recent findings are reassuring; others suggest a need for vigilance. Every year U.S. growers shower crops with an estimated 971 million pounds of pesticides, mostly to kill insects, weeds and fungi. But pesticide residues linger on crops and the surrounding soil, leaching into groundwater, running into streams and getting gobbled up by wildlife. The constant chemical trickle is an old worry for environmentalists. In the mid-1990s agribusinesses began advertising GM seeds that promised to reduce a farmer’s use of toxic pesticides. Today most GM crops—mainly soybean, corn, cotton and canola—contain genes enabling them to either resist insect pests or tolerate weed-killing herbicides. The insect-resistant varieties make their own insecticide, a property meant to reduce the need for chemical sprays. The herbicidetolerant types survive when exposed to broad-spectrum weed killers, potentially allowing farmers to forgo more poisonous chemicals that target specific weed species. Farmers like to limit the use of more hazardous pesticides when they can, but GM crops also hold appeal because they simplify operations (reducing the frequency and complexity of pesticide applications) and, in some cases, increase yields. But confirming environmental benefit is tricky. Virtually no peer-reviewed papers have addressed such advantages, which would be expected to vary from plant to plant and place to place. Some information is available, however. According to the U.S. Department of Agriculture, farmers who plant herbicidetolerant crops do not necessarily use fewer sprays, but they do apply a more benign mix of chemicals. For instance, those who grow herbicide-tolerant soybeans typically avoid the most noxious weed killer, turning instead to glyphosate herbicides, which are less toxic and degrade more quickly. Insect-resistant crops also bring mixed benefits. To date, insect resistance has been provided by a gene from the soil bacterium Bacillus thuringiensis (Bt). This gene directs cells to manufacture a crystalline protein that is toxic to certain insects—especially caterpillars and beetles that gnaw on crops—but does not harm other organisms. The toxin gene in different strains of Bacillus. thuringiensis can affect different mixes of insects, so seed makers can select the version that seems best suited to a particular crop. Defining the environmental risks of GM crops seems even harder than calculating their benefits. At the moment, public attention is most trained on Bt crops, thanks to several negative studies. Regulators, too, are surveying the risks intensely. This spring or summer the EPA is expected to issue major new guidelines for Bt crops, ordering seed producers to show more thoroughly that the crops can be planted safely and monitored in farm fields. In the face of mounting consumer concern, scientists are stepping up research into the consequences of Bt and other GM crops. Among their questions: How do Bt crops affect "nontarget" organisms—the innocent bugs, birds, worms and other creatures that happen to pass by the modified plants Will GM crops pollinate nearby plants, casting their genes into the wild to create superweeds that grow unchecked What are the odds that the genetically engineered traits will lose their ability to protect against insects and invasive weeds, leaving GM plants suddenly vulnerable What’s the conclusion of the passage towards the controversial issue of GM crops

A. GM crops could be environmentally beneficial and thus would be an essential tool for helping to feed the world’s burgeoning population.
B. GM crops cause too many concerns which would finally lead to restricting the planting of GM agricultural products.
C. The reassuring scientific findings bring more confidence in GM agricultural products.
D. As there are both supportive and negative findings of GM plants, the issue is till open to debate.

查看答案

Recently, there has been a hot debate about whether we Chinese people should bring back the traditional Chinese characters. We have been using those simplified Chinese characters since we learned to read and write. What do you think Write an essay of about 400 words on the following topic: Should We Bring Back the Traditional Chinese Characters In the first part of your essay you should state clearly your main argument, and in the second part you should support your argument with appropriate details. In the last part you should bring what you have written to a natural conclusion or make a summary. Marks will be awarded for content, organization, grammar and appropriateness. Failure to follow the above instructions may result in a loss of marks.

查看答案