Archive for May, 2010

Do-It-Yourself Seismic Screening at Berkeley Town House: Results

Monday, May 17th, 2010

This evening, fifteen BTH residents attended a presentation and lively discussion about the process of screening our own building for seismic risks, the results, and the implications. The issue of seismic vulnerability at BTH arises from the fact that it is about 50 years old, predating major additions to seismic knowledge, and it is within a mile of the Hayward Fault, whose next major earthquake is expected to be disastrous.

The slides from my presentation summarize the history of arguments about this building’s seismic strength, then describe two methods of do-it-yourself seismic screening of reinforced concrete buildings, which I recently applied to BTH. FEMA 154 (“Rapid Visual Screening”, or RVS) is a simple method promoted by FEMA. P25 is a more complex rapid-screening method developed by academic seismic engineers in Turkey and Italy.

These two methods generally agree for BTH. The scores that they assign to BTH are high enough that buildings with these scores almost never collapse in major earthquakes. The standard recommendations from both methods are that buildings with such scores are not at enough risk of collapse to justify further expert seismic evaluation. Buildings with BTH’s score on the P25 method have often suffered moderate or slight damage, and often have remained undamaged, while rarely suffering heavy damage. The P25 method suggests we be prepared for damages costing up to $1.5 million to repair.

There are sources of uncertainty about these conclusions, including (1) the inherent crudeness of such empirical, statistically based methods, (2) special sources of strength and weakness in the design of BTH that may make it atypical, and (3) errors in judgment or calculation that I may have made in my application of these methods.

I have communicated with four highly reputable seismic engineers over the last few months about work that they might be able to do to help BTH assess its seismic risks. I don’t recall any of them suggesting these or similar do-it-yourself methods to help us decide whether to retain expert consulting services. In one case I raised this subject and the engineer’s reply dismissed all such methods as nearly uninformative and largely a waste of time. However, it is also reputable seismic engineers who have developed and are advocating the use of such methods. Thus, there appears to be dissensus in the profession, and we are left to decide for ourselves.

Do-It-Yourself Seismic Screening at Berkeley Town House: Preview

Wednesday, May 12th, 2010

Presentation and Discussion

Monday, 17 May 2010, 6:30-8:00 p.m.

Berkeley Town House Multipurpose Room

Earthquake engineers have developed some do-it-yourself seismic screening methods for reinforced concrete buildings. In this presentation, I’ll describe two such methods: FEMA 154 and P25. I’ll show, step by step, how I applied them to BTH and what scores the building earned. You will be able to check and revise my work. We’ll then discuss how credible the scores are, what they predict, what other predictions have been made for BTH, and whether further seismic assessment for this building is rational.

P25 method calibration report

PanLex Translation Interface

Tuesday, May 11th, 2010

I’m developing a Web application that you can use to translate words into hundreds of languages.

This application demonstrates the use of PanLex, an emerging panlingual lexical database sponsored by Utilika Foundation. The bare-bones interface lets the user enter a word or phrase (in the user’s language), and offers all the translations of it that PanLex currently contains.

So far, I have implemented the tool in two languages: Esperanto and Turkish. The Esperanto interface is InterVorto and the Turkish interface is TümSöz.

After some more work on portability, it should take about 5 minutes each to extend it to other languages. PanLex currently contains data in about 1300 languages.

The only translations offered by this tool are attested ones: translations approved by contributors. These vary greatly in number. For example, InterVorto can translate the Esperanto word  “balotilo” into only 8 languages, but can translate the word “akvo” into 668 languages. If you want translations into more languages, you can follow a link to PanLem, a more comprehensive (and expert-level) PanLex interface, which allows you to see two-step translations (translations of translations). PanLem is bleeding-edge work, in which I am limiting the UI to purely lemmatic labels so PanLex can localize itself into any language that it covers. So, if you follow that link, be prepared to explore.

Usability comments on the tool are, of course, very welcome.

Cumulative Voting in a California Housing Cooperative

Monday, May 10th, 2010

There are many ways to design a voting system, and they have various arguable benefits. One class of voting systems has been called “semiproportional”, and one system in that class is called “cumulative voting”. With cumulative voting, each voter allocates numbers to candidates, with the total of the numbers being limited; the candidates with the largest totals of numbers are elected.

For housing cooperatives in California, cumulative voting has the distinction of being explicitly dealt with in the law. It is mentioned in the California Corporations Code and in the California Civil Code (section 1363.03(a)).

But it’s not obvious whether the law permits or prohibits cumulative voting in a corporate housing cooperative. The Corporations Code permits it for nonprofit mutual benefit corporations (in section 7615) and for nonprofit public benefit corporations (section 5616), but prohibits it in consumer cooperative corporations with individuals as members (in section 12224). That section permits it only for “central organizations”, which, according to section 12256, are organizations of organizations. But the Civil Code permits all common-interest housing developments (including housing cooperatives of all the above three kinds) to provide for cumulative voting in their governing documents. The Civil Code claims precedence over the Corporations Code with regard to voting rules for mutual benefit corporations (section 1363.03(n)), but apparently doesn’t claim precedence for the other two kinds. (Thanks to Susan Colowick for her research on this.)

So, for Berkeley Town House Cooperative Corporation, which is a common-interest development organized as a consumer cooperative corporation, the two laws seem to say opposite things. If BTHCC wants to consider cumulative voting, may it? Adams Kessler, a law firm that provides services to common-interest developments, claims that the answer to this question is “yes”, but ignores the apparent contradiction between laws for housing cooperatives organized as consumer cooperatives.

If a housing cooperative may adopt cumulative voting, should it? There’s a vigorous debate over the merits of cumulative voting and other semiproportional voting systems, but reading the advice of Adams Kessler you wouldn’t know it. Adams Kessler opinionatedly rejects cumulative voting with sneer words like “disruptive, fringe, and single-issue candidates”. I guess that if a housing cooperative were dominated by racists Adams Kessler would advise it to junk cumulative voting so as to keep its board of directors racially pure. If the current board of directors were violating members’ rights to information and a group of members wanted somebody on the board who would respect their rights, it looks as if Adams Kessler would advise the corporation against cumulative voting to keep that group from “disrupting” the community by electing a sympathetic director. Thanks for your advice, Adams Kessler, but you seem dedicated to reinforcing the entrenched interests, which may not always coincide with the general welfare of the members.

Nonlemmatic ambiguity

Saturday, May 8th, 2010

Susie and I this week walked up to the University of California Botanical Garden and inundated our senses with vegetation from the world over. I was amazed at how the plants, many of them fragile-looking, survive in an alien climate amidst one another and the largely out-of-supervisor-sight visitors.

My amazement grew when I encountered a sign that seemed to invite visitors to devour any nonpoisonous plants:

Do Not Eat Toxic Plants

Sign at U of Cal Botanical Garden

BTH Campaign Poster 2

Saturday, May 1st, 2010
Say no to bias. Vote for Pool.

Poster 2 in my campaign for BTH Director.