bluuebunny/crossref_metadata_2025 huggingface dataset:
Coherent population transfer in molecules coupled with a dissipative environment by an intense ultrashort chirped pulse
Authors: Fainberg B. D. , Gorbunov V. A.
Published: October 2002

We have studied the intense chirped pulse excitation of a molecule coupled with a dissipative environment taking into account electronic coherence effects. We considered a two-state electronic system with relaxation treated as a diffusion on electronic potential energy surfaces. This relaxation model enables us to trace continuously the transition from a coherent population transfer to incoherent one. An inhomogeneously broadened system with frozen nuclear motion is invoked to model a purely coherent transfer. We show that the type of population transfer (coherent or incoherent) strongly depends on the pulse chirp, its sign, and the detunings of the exciting pulse carrier frequency with respect to the frequency of the Franck-Condon transition. For positive chirped pulses and moderate detunings, relaxation does not hinder a coherent population transfer. Moreover, under these conditions the relaxation favors more efficient population transfer with respect to the “coherent” system with frozen nuclear motion.
Heteroepitaxial growth behavior of SrRuO3/SrTiO3(001) by pulsed laser deposition
Authors: Kim Sang Sub , Seong Tae Yeon , Kim Hyun Seung , Je Jung Ho
Published: October 2002

Heteroepitaxial growth behavior of SrRuO3/SrTiO3(001) thin films during early stages by pulsed laser deposition was investigated using synchrotron x-ray scattering, atomic force microscopy, and high-resolution transmission electron microscopy. We find that three-dimensional (3D) SrRuO3(110) islands of ∼1500 Å in diameter grow at an initial stage of growth (30 Å in thickness), in contrast to the two-dimensional layer growth previously reported in thick (3000 Å) films by off-axis sputtering. Interestingly, the 3D islands are coherently strained to the substrate, possessing a very narrow mosaic distribution of 0.007° half width at half maximum. On top of the existing well-aligned islands, poorly aligned 3D islands of much smaller sizes progressively grow, reducing the interfacial strain while maintaining the small surface roughness of 9 Å up to the film thickness of 420 Å.
Atomic structure of the nanocrystalline Si particles appearing in nanostructured Si thin films produced in low-temperature radiofrequency plasmas
Authors: Viera G. , Mikikian M. , Bertran E. , Cabarrocas P. Roca i , Boufendi L.
Published: October 2002

Nanostructured Si thin films, also referred as polymorphous, were grown by plasma-enhanced chemical vapor deposition. The term “polymorphous” is used to define silicon material that consists of a two-phase mixture of amorphous and ordered Si. The plasma conditions were set to obtain Si thin films from the simultaneous deposition of radical and ordered nanoparticles. Here, a careful analysis by electron transmission microscopy and electron diffraction is reported with the aim to clarify the specific atomic structure of the nanocrystalline particles embedded in the films. Whatever the plasma conditions, the electron diffraction images always revealed the existence of a well-defined crystalline structure different from the diamondlike structure of Si. The formation of nanocrystallinelike films at low temperature is discussed. A Si face-cubic-centered structure is demonstrated here in nanocrystalline particles produced in low-pressure silane plasma at room temperature.
Transition moments and excited-state first-order properties in the coupled-cluster model CC2 using the resolution-of-the-identity approximation
Authors: Hättig Christof , Köhn Andreas
Published: October 2002

An implementation of transition moments and excited-state first-order properties is reported for the approximate coupled-cluster singles-and-doubles model (CC2) using the resolution of the identity (RI) approximation. In parallel to the previously reported code for the ground- and excited-state amplitude equations, we utilize a partitioned form of the CC2 equations and thus eliminate the need to store any N4 intermediates. This opens the perspective for applications on molecules with 30 and more atoms. The accuracy of the RI approximation is tested for a set of 29 molecules for the aug-cc-pVXZ (X=D,T,Q) basis sets in connection with the recently optimized auxiliary basis sets. These auxiliary basis sets are found to be sufficient even for the description of diffuse states. The RI error is compared to the usual basis set error and is demonstrated to be insignificant.
Photodissociation spectroscopy and dynamics of Mg+-formaldehyde
Authors: Lu W.-Y. , Wong T.-H. , Sheng Y. , Kleiber P. D.
Published: October 2002

We have carried out photodissociation spectroscopy studies of the bimolecular complex Mg+(H2CO) in the visible and near-uv regions. The work is supported by electronic structure calculations of the ground and low-lying excited states of the complex. Mg+-formaldehyde is bound in a C2v Mg+–O=CH2 geometry with a theoretical bond energy of De″(Mg-OCH2)=1.35 eV. The complex shows absorption bands that correlate with Mg+-based and formaldehyde-based radiative transitions. The lowest-energy band is assigned as Ã 2A′(2B1)←X̃ 2A1, to an excited state of mixed Mg+(3pπ) and H2CO(π*) orbital character. The band exhibits complex vibrational structure with considerable excitation of the CH2 out-of-plane wag and C=O stretch modes; the vibrational frequencies are shifted dramatically from their values in the ground state, showing the effect of a significant weakening of the C=O bond and out-of-plane distortion of the complex. Excitation in the Mg+-based B̃ 2A′(2B2)←X̃ 2A1 band shows predominantly low-frequency vibrational motions assigned to the intermolecular in-plane wag and Mg-O stretch modes. Birge–Sponer analysis gives the Mg–O bond energy in the ground state as De″=1.29 eV. Partially resolved rotational substructure clearly demonstrates a change in geometry from a linear or near linear Mg-O-C (C2v) ground state to a bent (Cs) excited state [θ(Mg-O-C)=139°±3°]. Spectroscopic rotational constants are in very good agreement with ab initio predictions for this band. The Mg+-based D̃ 2A1←X̃ 2A1 band also exhibits pronounced vibrational structure including strong Mg–O and C=O stretch signals, consistent with formation of a partial Mg–O σ bond in this state. Mg+ is the major dissociation product through the uv–visible region. However, in the B̃←X̃, C̃←X̃, and D̃←X̃ absorption bands, we also observe a substantial branching to the reactive dissociation product MgH+. The reactive branching ratio increases with photon energy through the absorption bands, reaching a reactive quantum yield of ∼13 in the D̃←X̃ band. Our results suggest that there is no significant activation barrier to reaction above the endothermicity.
Thermally stable, oxidation resistant capping technology for Ti/Al ohmic contacts to n-GaN
Authors: Pelto Christopher M. , Chang Y. Austin , Chen Yong , Williams R. Stanley
Published: October 2002

The intermetallic TiAl3 has been used as a thermally stable cap for Ti/Al ohmic contacts to n-GaN. The electrical performance of the TiAl3-capped contact is nearly the same as that of a standard Ti/Al/Ni/Au contact processed on the same substrate, but the Ti/Al/TiAl3 contact’s performance is optimized at a much lower temperature. The Ti/Al/TiAl3 contact achieved a lowest specific contact resistance (ρc) of 2.1×10−5 Ω cm2 following 1 min at 700 °C in flowing, oxygen-gettered ultrahigh purity (UHP) Ar. The Ti/Al/Ni/Au contact standard achieved a ρc of 1.8×10−5 Ω cm2 following a 15 s anneal at 900 °C in flowing, oxygen-gettered UHP Ar. The TiAl3-capped contact structure shows little sensitivity to the amount of oxygen in the annealing ambient for optimization, and we found that it could achieve a ρc of 1.1×10−5 Ω cm2 following 5 min at 600 °C in air. This performance is almost identical to that attained when the contact was annealed in oxygen-gettered UHP Ar and ordinary Ar. Anneals were extended to a total time of 20 min in the three ambient atmospheres, and the Ti/Al/TiAl3 contact showed no significant difference in its performance. The fact that this contact structure can withstand optimization anneals in air suggests that it could be annealed alongside a Ni/Au contact to p-GaN in air and still achieve a low contact resistance. The performance of the TiAl3-capped bilayer was found to be stable following thermal aging for more than 100 h at 350 °C in air, which was also comparable to an optimally annealed Ti/Al/Ni/Au contact aged at the same time. The TiAl3 material should be an oxidation cap solution for many other Ti/Al contact structures, almost regardless of the Ti:Al layer thickness ratio, since the TiAl3 will be stable on the upper Al layer. Use of this cap eliminates the need to alter a previously optimized bilayer, thus it is a means of enhancing any existing Ti/Al bilayer contact’s performance without necessitating the reoptimization of the layers to accommodate the cap.
Optical constants and roughness study of dc magnetron sputtered iridium films
Authors: Yan Li , Woollam John A.
Published: October 2002

Extremely smooth thin films of iridium have been deposited onto superpolished fused silica substrates using dc magnetron sputtering in an argon plasma. The influence of deposition process parameters on film microroughness has been investigated. In addition, film optical constants have been determined using variable angle spectroscopic ellipsometry, over the spectral range from vacuum ultraviolet to middle infrared (140 nm–35 μm). Because the Ir films were optically thick and the surface roughnesses were measured by atomic force microscopy then accounted for in the optical model, the as-determined film optical constants are expected to be the best available for Ir bulk metals, minimally affected by surface overlayers or microstructure.
Combined thermionic-thermoelectric refrigerator
Authors: Xuan X. C.
Published: October 2002

A combined thermionic-thermoelectric refrigerator is proposed. The passive metal conductor in a vacuum thermionic refrigerator is replaced by an active p-type thermoelectric element, so that the Peltier cooling power can be exploited. Complete analytic formulas of performances are derived for the two types of thermionic refrigerators at both maximum cooling power density and optimum coefficient of performance. In employing the ideal material properties as Nolas and Goldsmid have done [J. Appl. Phys. 85, 4066 (1999)], we have proved quantitatively the combined thermionic-thermoelectric refrigerator to be more effective and efficient than a thermionic or thermoelectric device.
Extraction of spatio-temporal distribution of power dissipation in semiconductor devices using nanosecond interferometric mapping technique
Authors: Pogany D. , Bychikhin S. , Litzenberger M. , Gornik E. , Groos G. , Stecher M.
Published: October 2002

A method for the extraction of power dissipation sources inside semiconductor devices on a nanosecond-time scale is proposed using a backside transient interferometric mapping technique. The two-dimensional power dissipation density is extracted from the time and space derivative of the measured optical phase shift. The method is applied to the analysis of moving current filaments in an electrostatic discharge protection device operating in the avalanche regime. It is found that the filament dynamics is governed by the negative temperature dependence of the impact ionization coefficient. The total power calculated from the optical measurements is in excellent agreement with the electrical input power.
Features of the magnetic properties of rare-earth intermetallides RMn2Ge2 (Review)
Authors: Kolmakova N. P. , Sidorenko A. A. , Levitin R. Z.
Published: October 2002

The magnetic and other physical properties of the ternary intermetallic compounds RMn2Ge2 (R is a rare earth) are of great interest on account of effects due to the coexistence of the 3d (manganese) and 4f (rare-earth) magnetic subsystems. The layered structure, the high sensitivity of the exchange parameters to the interatomic distances, the antiferromagnetic exchange interaction in the manganese subsystem in intermetallides containing heavy rare earths, and also the appreciable crystal-field effects in the rare-earth subsystem make for complex magnetic phase diagrams in these compounds. A review is given of the experimental and theoretical research on the magnetic properties and magnetic phase diagrams of the intermetallic compounds RMn2Ge2, including measurements in high and ultrahigh magnetic fields. A theoretical model is proposed which takes into account the features of the crystal structure and the hierarchy of exchange interactions in intermetallides containing heavy rare earths; this model is in many cases capable of describing the magnetic properties of these intermetallides over a wide range of magnetic fields and temperatures, and it permits determination of the interaction parameters for RMn2Ge2 compounds with R=Gd and Dy from a comparison of the experimental and calculated magnetization curves and H–T phase diagrams.
Signal decay and amplitude measurements of antiferromagnetically coupled magnetic recording media
Authors: Moser Andreas , Margulies David T. , Rettner Charles T. , Fullerton Eric E.
Published: October 2002

Using a conventional spin stand we have investigated the recording and decay processes of antiferromagnetically coupled (AFC) longitudinal magnetic media. For AFC media with thick lower layers, both the signal amplitude and decay oscillate when measured as a function of transition density. Using heads with different write-pole geometries, we find that the oscillation frequency scales with the thickness of the write pole, from which we conclude that the magnetic field at the trailing edge of the write head is sufficiently large to write transitions into the lower layer of the AFC media.
Real-time determination of the segregation strength of indium atoms in InGaAs layers grown by molecular-beam epitaxy
Authors: Martini S. , Quivy A. A. , da Silva E. C. F. , Leite J. R.
Published: October 2002

The surface segregation of indium (In) atoms was investigated during the growth of InGaAs layers by reflection high-energy electron diffraction (RHEED). We observed that the decay constant of the RHEED-oscillation amplitude during growth depends on the growth conditions and is related, in a very simple way, to the segregation coefficient of the In atoms in the InGaAs layers.
Structural, dielectric, and magnetic properties of epitaxially grown BaFeO3 thin films on (100) SrTiO3 single-crystal substrates
Authors: Matsui T. , Tanaka H. , Fujimura N. , Ito T. , Mabuchi H. , Morii K.
Published: October 2002

We have prepared single-crystalline films of BaFeO3, which may contain high valent Fe4+ ions, on (100) SrTiO3 substrates by pulsed laser-beam deposition. The reflection high-energy electron diffraction patterns for the films apparently show a C4 symmetry operation, suggesting that the sample had a pseudocubic perovskite structure rather than hexagonal unit cell. The films were found to be highly insulating, and showed a high value of dielectric constant of ε=59. At 300 K, the magnetization loop of the film apparently shows hysteresis, as well as small remanent magnetization. These characteristics are totally different from those of bulk BaFeO3.
Clustering of Economic Activities in Polycentric Urban Regions: The Case of the Randstad
Authors: Kloosterman Robert C. , Lambregts Bart
Published: October 2002

Local contexts are becoming more important as the impact of the process of globalisation on the spatial distribution of economic activities seems to generate not so much processes of homogenisation as of heterogenisation between regions in advanced economies. The combination of specialisation and spatial concentration of economic activity in advanced economies has attracted much attention from economists and geographers. Here, we explore at what level of spatial aggregation contemporary tendencies of clustering of economic activities articulate themselves within the archetypal polycentric urban region of the Dutch Randstad. To examine this question, we look at profiles of business start-ups in the individual cities of the Randstad. Our focus is on business start-ups as they respond most directly to the changes taking place in the economic environment and especially those regarding the supply of labour. Our findings point to the direction of cluster formation at a supraurban level. The profiles of business start-ups are clearly converging. A process of intraregional-i.e. at the level of the polycentric urban region-homogenisation with respect to new economic activities is taking place. Within the Randstad, notably a decreasing divide between a north wing and a south wing is revealed.
Revolution in Social Housing in the Netherlands: Possible Effects of New Housing Policies
Authors: van Kempen Ronald , Priemus Hugo
Published: October 2002

The social rented sector in the Netherlands has always had a very special status. Unlike many other countries, in the Netherlands this sector has never been regarded as a segment exclusively for low-income households. Consequently, neighbourhoods with large numbers of social rented dwellings have never been areas for low-income households only. Since about 1990, however, the proportion of low-income households in social rented housing has increased, while high-income households can be found more and more in the owner-occupied sector. At least for the 1990s, housing policies can be seen as partially responsible for this change. In this contribution, we argue that new housing policies in the Netherlands will probably have the effect of increasing the share of low-income households in social housing even more. This holds for the policy of urban restructuring, initiated in 1997, as well as for the newest plans of the State Secretary of Housing that were launched in his Housing Memorandum at the end of the year 2000. If the proposed housing policy is implemented in the near future, we doubt whether the status of social housing in the Netherlands will continue to be so different from that of other EU countries.
Quantifying Spatial Characteristics of Cities
Authors: Srinivasan Sumeeta
Published: October 2002

Land-use initiatives represent a potentially effective tool for coping with the kinds of mobility pattern that North American cities faced in the 1990s and still face in the present century. As fine-grained data about land use and travel activity become available, they provide the opportunity to improve our understanding of the linkage between land use and transport. This paper examines in detail the neighbourhood characteristics that could affect mode choice on the work and non-work tour. Neighbourhood characteristics include land use, network and accessibility-related characteristics which are quantified through the use of geographical information systems (GIS). Ultimately, such measures could be used in conjunction with detailed surveys of travel behaviour to specify, calibrate and use models of modal choice and residential choice that are more sensitive to the fine-grained spatial structure of neighbourhoods and transport corridors in metropolitan areas. Micro-level data for the Boston metro area, together with a 1991 activity survey of approximately 10 000 residents, provide a rich empirical basis for experimenting with relevant neighbourhood measures and for simulating the effects on travel behaviour. We find that spatial characteristics do affect mode choice, both for the relatively (spatially) restricted non-work tour and the work tour.
A Systematic Study of an Urban Foodscape: The Price and Availability of Food in Greater Glasgow
Authors: Cummins Steven , Macintyre Sally
Published: October 2002

Previous research has suggested that foods which are beneficial to health may be more expensive, and more difficult to obtain, in deprived compared with more affluent areas, and that this may help to explain the greater adherence to healthy eating guidelines consistently reported in more affluent areas of the UK. In this paper, we report on an investigation of the price and availability of 57 foods, previously defined as representing a 'modest but adequate diet', in different retail formats and areas differing in socioeconomic deprivation within Greater Glasgow. In this setting, shop type was the main predictor of food price and availability, cheaper prices and greater availability being mainly found in multiple and discount stores, which were more likely to be located in more deprived rather than affluent areas. Prices did not vary greatly by area deprivation and, when they did, they tended to be lower in poorer areas. Foods cheaper in poorer areas tended towards the high-fat, high-sugar types, the consumption of which current dietary guidelines suggest need to be reduced. We suggest that these findings point to the need for more systematic, empirical, large-scale studies of variations in food price and availability, and their public health consequences.
Estimating Neighbourhood Effects in House Prices: Towards a New Hedonic Model Approach
Authors: Tse Raymond Y. C.
Published: October 2002

A hedonic equation considers OLS models with independently and identically distributed errors. However, quality of property and location tend to exhibit highly auto-regressive correlation due to spatial dependence and heterogeneity. A modification is made to multiple regression analysis based on the land-rent concept so that the modified hedonic house price function can be determined. This paper develops a stochastic approach which is able to correct autocorrelation bias in the hedonic function. Others tend to model the spatial autocorrelation through the error terms, while this study models it through the constant term. The sample was orientated by location to reflect the neighbourhood effects. Thus the neighbourhood effects can be separated from the random disturbance. Our model, using data from Hong Kong, incorporates adjustments reflecting net floor area ratio, age, floor level, views, transport accessibility and amenities such as availability of recreational facilities. The stochastic model is a more flexible application of hedonic price regressions, making it an appealing alternative to spatial problems.
Development Cultures and Urban Regeneration
Authors: Guy Simon , Henneberry John , Rowley Steven
Published: October 2002

The importance of levering private finance and investment into urban regeneration is a central consideration of policy. Attention has focused on institutional investors' motives for holding regeneration investments and on how they might be encouraged to put more money into inner-city areas. The paper argues that, while helpful, the impact of such an approach upon urban regeneration will be limited. This is because, by definition, institutional investors are only interested in institutional property and buildings which do not conform to this frame of reference will not be of interest to them. However, other actors see things differently. Independent developers embrace the challenge presented by fringe locations, mixed uses and the local urban culture and aesthetic—and translate these characteristics into development values. Urban policy needs to address the contrasting ways in which the nature, construction and application of investors' strategic rationality intercept with local development conditions. In particular, greater emphasis should be given to encouraging independent, locally based forms of property investment and development.
Pathways to a World City: Shanghai Rising in an Era of Globalisation
Authors: Yusuf Shahid , Wu Weiping
Published: October 2002

In a globalising world, cities at or near the apex of the international urban hierarchy are among the favoured few—New York, London and Tokyo—that have acquired large economic, cultural and symbolic roles. Among a handful of regional aspirants, such as Hong Kong, Miami and Sao Paulo, Shanghai has reasonable long-term prospects. If the Chinese economy can sustain its growth rate, it will rival the US in a few decades. And if Shanghai is able to retain its pre-eminence in the Chinese context, then it is likely to be the East Asian city with the best prospect of becoming a global centre. This paper briefly explores the makings of a world city, identifies certain necessary ingredients, examines Shanghai's recent development, indicates national and municipal policies that may determine Shanghai's pathway to a global city and shows how such policies are being implemented.
Managing Nature and Narratives of Dispossession: Reclaiming Territory in Cardiff Bay
Authors: Cowell Richard , Thomas Huw
Published: October 2002

This paper builds upon Watts and Peet's notion of an 'environmental imaginary' to conceptualise the distinctive ways in which the politics of nature are inserted into urban regeneration strategies. In particular, it seeks to examine how regional discursive formations frame the scope for a transformation of urban ecological politics. The chosen case study, the redevelopment of Cardiff Bay, would seem to have offered a significant opportunity for fashioning a more radical urban ecological politics, because the strategy's proponents bridged social and ecological worlds in an unusually explicit way in their justificatory narratives of dispossession, bound up with a major physical reconstruction of the dockland environment. These narratives are shown to be grounded in the historical development of the near-hegemonic regional coalitions of south Welsh politics, and to unfold in the treatment of both the ethnic minority residential community within Cardiff's docks, and the estuarine environment, as 'deviant' in a number of respects—in need of 'reclamation' and 'integration' with the rest of Cardiff and Wales as a whole. The analysis considers why radical ecological politics failed to develop and whether the contradictions inherent in the regeneration strategy might yet encourage its emergence.
Power and Conflict in Pro-growth Regimes: Tensions in Economic Development in Jersey City and Detroit
Authors: Lawless Paul
Published: October 2002

Jersey City and Detroit provide contrasting experience of the policy and politics in two US cities. Both can be seen as idealised 'pro-growth' regimes. Jersey City has benefited from the relocation of commercial and residential development out of Manhattan. The city has actively pursued new investment and has instigated various policies designed to spread the benefits of development across different sectoral and spatial communities. Detroit has endured enormous economic collapse, although there are limited signs of enhanced physical development. Policy-making and linkage programmes remain limited and contested. Overall reflections on policy-making in these cities point to the apparent importance of the mayor, a complex institutional environment, weak bureaucracies and interagency and intra-agency conflict. Regime formation remains relatively weak, especially in Detroit. In both areas, coalition-building can be overstressed to the detriment of the realities of, and opportunities created by, economic change in the wider economy.
The Emergence of the Urban Land Market in China: Evolution, Structure, Constraints and Perspectives
Authors: Xie Qingshu , Ghanbari Parsa A.R. , Redding Barry
Published: October 2002

Urban land reform is one of the most important constituents of China's whole economic reform programme launched in the late 1970s. Through a series of reforms, urban land markets have emerged rapidly. This paper aims to analyse the evolution of urban land reform, to discuss the structure of urban land markets, to identify the principal constraints in the urban land market and to propose relevant recommendations for its improvement in the future. The methodology employed for this research is based on the structure and agency theory of the development process and the paper relies on a comprehensive review of recent research on the urban land market in China.
Classifying Local Retail Property Markets on the Basis of Rental Growth Rates
Authors: Jackson Catherine
Published: October 2002

Diversification strategies for the property element of portfolios have traditionally been undertaken on a sectoral/regional basis, primarily due to data restrictions. However, the standard regions in the UK are defined for administrative purposes and are likely, therefore, to be composed of heterogeneous property markets. The development of an alternative classification, based on local property markets, is investigated. This is based on annual retail rental growth rates and is developed using cluster analysis. A number of issues emerge. Throughout the various stages of development and tests for temporal stability, the local markets group according to broad underlying rental drivers. However, more tightly defined clusters are unstable over time as a consequence of rental volatility at the local level. It is clear that markets do not form groups conforming to the geographical regions that are widely analysed and that traditionally form the basis for diversification.
Bridging the Divide? Complementary Perspectives on Property
Authors: Guy Simon , Henneberry John
Published: October 2002

In a recent paper, we argued for the need to develop an understanding of property development processes which combines a sensitivity to the economic and social framing of development strategies with a fine-grain treatment of the locally contingent responses of property actors. This is a response to Ball's criticisms of that paper, which offer a misleading characterisation of our methodological and theoretical position with regard to property research.
Rewriting Rebellion and Mapping Memory in South Korea: The (Re)presentation of the 1980 Kwangju Uprising through Mangwol-dong Cemetery
Authors: Yea Sallie
Published: October 2002

In May 1980, one of the most tragic events in the history of modern South Korea took place. This was the violent repression of civilian demonstrations in the south-western city of Kwangju, during which over 200 people were killed and hundreds more wounded and tortured by the South Korean government of General Chun Doo Hwan. Now, over 20 years later, the uprising has taken on a new national significance and legitimacy and is being (re)interpreted as the major catalyst for democratic reform in South Korea. The recent 'official' reinterpretation of the uprising has meant that it has become the subject of extensive memorialisation by the Korean state. This paper looks at the process by which the Kwangju Uprising has become reinterpreted, memorialised and subsequently contested in the late 1990s in Kwangju city through a number of 'sites of memory' (memorial sites), including Mangwol-dong Cemetery, where the victims of the uprising are buried.
Politicised Pagodas and Veiled Resistance: Contested Urban Space in Burma
Authors: Philp Janette , Mercer David
Published: October 2002

The urban landscapes of Yangon and Mandalay in Burma (Myanmar) exhibit a rich cultural layering and complex blending of urban forms and architectural styles. But while both cities today are shaped by contemporary economic and political realities, they also clearly reflect their historical origins—Yangon as the British colonial capital and Mandalay as the last seat of the monarchy. Burma's ancient religious monuments, monarchical and colonial heritage on the one hand, and new religious edifices, international standard hotels, commercial enterprises, new public buildings and satellite towns on the other hand, represent the two poles of the dialectic of tradition and modernity. The landscapes, as symbolic representations, have been appropriated by the authoritarian military regime, the State Peace and Development Council (SPDC) for nation-building purposes. But the urban landscapes are also contested and appropriated in symbolic ways and invested with meanings as sites of resistance and struggle by those in opposition, and are thus contested sites where the power relations of domination and resistance intersect. The paper illustrates these themes with examples drawn from Yangon and Mandalay.
Out of Control: Emergent Cultural Landscapes and Political Change in Urban Vietnam
Authors: Thomas Mandy
Published: October 2002

This paper plots the recent changes in the uses of public space in Hanoi, Vietnam. It is argued that the economic and social changes in contemporary Vietnam have paved the way for a dramatic transformation in the ways in which streets, pavements and markets are experienced and imagined by the populace. The efflorescence of individual mobility, street-trading and public crowding around certain popular events has led to the emergence of a distinct public sphere, one which is not immune from state control and censure but which is a flagrant rebuttal of the state's appeal. The immediate struggles over space herald a new discursive arena for the contest over Vietnamese national imagery as represented in cultural heritage and public space, memorials and state-controlled events which the public are rapidly deserting. The paper concludes by suggesting that the everyday cultural practices that have created a bustling streetlife in urban Vietnam will inevitably provide the vitality and spectacle for the destabilisation of state control in a struggle for meanings in public space.
The Village of the Poor Confronts the State: A Geography of Protest in the Assembly of the Poor
Authors: Missingham Bruce
Published: October 2002

This paper describes the strategic use of space and construction of place by the Assembly of the Poor demonstration in Thailand in 1997. It aims to further our understanding of the symbolic meanings and political power of the protest. The Assembly of the Poor occupied the streets outside Government House in Bangkok and transformed them into an eye-catching and highly symbolic place of protest, the 'Village of the Poor'. The Village of the Poor symbolically brought the rural village into the heart of the city. In doing so, the protesters disrupted conventional representations and stereotypes of the 'village' and rural life as an enduring source of Thai culture and national identity. This village represented a community in crisis, threatened by the very development and economic growth the city symbolises and depends upon. The demonstration endured for over three months, and within the Village of the Poor the signs and symbols of protest were strikingly combined with the everyday, domestic activities of the villagers. On the streets and footpaths, even seemingly simple, intimate activities, such as eating, bathing and sleeping, became symbolic, signifying the protesters' persistence and resistance to inequitable development in their petition to the state.
'Vagrants Wearing Make-up': Negotiating Spaces on the Streets of Yogyakarta, Indonesia
Authors: Beazley Harriot
Published: October 2002

Since the start of the financial crisis in late 1997, there has been a significant increase in the numbers of children living and working on the streets of Indonesia, including a dramatic rise in street girls. All street children are marginalised by the state and mainstream society, and this is reflected in the marginality of the spaces they occupy in the streets. In Indonesia, street children are seen by mainstream society to be committing a social violation, as their very presence contradicts state ideological discourse on family values and ideas about public order. Such an offence justifies the 'cleaning up' of children from the streets, arrests, imprisonment and, in some extreme cases, torture. This paper seeks to explain how girls in particular suffer discrimination on the streets, and how their social position is doubly marginal to that of street boys. This is because they are seen to be actively violating the construction of femininity in mainstream discourse, where the street is 'no place for a girl', an ideology that street boys also adhere to. By examining the lives and experiences of a group of street girls, the paper describes how they are not passive victims of the male gaze, but survivors who actively reject the roles society expects of them. Their behaviour patterns are explained as survival mechanisms that are articulated through their style, income-earning activities and the production of street girl identities. The paper shows how street girls negotiate social and personal spaces that are different from those of boys, and how they have succeeded in creating their own gendered sense of place on the street. These socio-spatial patterns are explained as 'geographies of resistance', which are a response to the pervasive patriarchal discourse within Indonesian society, a society which believes that girls, in particular, should not be on the streets.
Coordinated methyl and RNA binding is required for heterochromatin localization of mammalian HP1α
Authors: Muchardt Christian , Guillemé Marie , Seeler Jacob‐S , Trouche Didier , Dejean Anne , Yaniv Moshe
Published: October 2002

In mammalian cells, as in Schizosaccharomyces pombe and Drosophila, HP1 proteins bind histone H3 tails methylated on lysine 9 (K9). However, whereas K9‐methylated H3 histones are distributed throughout the nucleus, HP1 proteins are enriched in pericentromeric heterochromatin. This observation suggests that the methyl‐binding property of HP1 may not be sufficient for its heterochromatin targeting. We show that the association of HP1α with pericentromeric heterochromatin depends not only on its methyl‐binding chromo domain but also on an RNA‐binding activity present in the hinge region of the protein that connects the conserved chromo and chromoshadow domains. Our data suggest the existence of complex heterochromatin binding sites composed of methylated histone H3 tails and RNA, with each being recognized by a separate domain of HP1α.
Composition of the central stalk of the Na+‐pumping V‐ATPase from Caloramator fervidus
Authors: Chaban Yuriy , Ubbink‐Kok Trees , Keegstra Wilko , Lolkema Juke S , Boekema Egbert J
Published: October 2002

The Na+‐pumping V‐ATPase complex of the thermophilic bacterium Caloramator fervidus was purified and dissociated under controlled conditions. The structure of purified V1‐ATPase subcomplexes differing in subunit composition was analyzed by electron microscopy and single particle analysis of 50 000 projections. Difference mapping of subcomplex projections revealed the presence and position of two subunits in the central stalk. A density with an elongated shape similar to the γ subunit of F‐ATPases is partly located within V1 and corresponds, most likely, to subunit E. Subunit E is connected to the membrane‐bound part V0 via subunit C, a spherical density that is connected to the center of V0. The presence of subunit C makes the central stalk substantially longer in comparison to the F‐ATPases, in which the γ subunit connects directly to F0.
Genomic Evidence for COP1 as a Repressor of Light-Regulated Gene Expression and Development in Arabidopsis[W]
Authors: Ma Ligeng , Gao Ying , Qu Lijia , Chen Zhangliang , Li Jinming , Zhao Hongyu , Deng Xing Wang
Published: October 2002

Microarray gene expression profiling was used to examine the role of COP1 in the light control of Arabidopsis genome expression. Qualitatively similar gene expression profiles were observed between wild-type seedlings grown in white light and multiple cop1 mutant alleles grown in the dark. Furthermore, overexpression of the dominant-negative-acting N terminus of COP1 (N282) in darkness produced a genome expression profile similar to those produced by white light and the cop1 mutations. Different cop1 mutant alleles, N282, and light treatment also resulted in distinct expression profiles in a small fraction of the genes examined. In the light, the genome expression of cop1 mutations displayed an exaggerated light response. COP1-regulated genes in the dark were estimated to account for >20% of the genome. Analysis of these COP1-regulated genes revealed that >28 cellular pathways are coordinately but antagonistically regulated by light and COP1. Interestingly, the gene expression regulation attributable to HY5 in the light is included largely within those genes regulated by COP1 in the dark. Thus, this genomic study supports the hypothesis that COP1 acts as a repressor of photomorphogenesis, possibly by controlling the degradation of transcription factors and their target gene expression. The majority of light-controlled genome expression could be accounted for by the negative regulation of COP1 activity.
Training of the Two-Way Shape Memory Effect by Bending in NiTi Alloys
Authors: Lahoz R. , Gracia-Villa L. , Pue´rtolas J. A.
Published: October 2002

The two-way shape memory effect (TWSME), has been studied in a near-equiatomic NiTi commercial alloy. Two bending training methods have been applied on NiTi wires. One is based on the martensite deformation and the other on thermal cycling under constant bending curvature. The efficiency of each method has been evaluated with better results of TWSME in the martensite deformation method. Finite element simulation has been performed on wires, in the pure bending mode, in order to calculate the maximum tensile strain in the transversal section of the wire. These simulations have allowed us to compare our results with the TWSME data obtained in prior studies under the tensile mode.
Interpretation of standard distortion product otoacoustic emission measurements in light of the complete parametric response
Authors: Mills David M.
Published: October 2002

Emission characteristics (at 2 f1–f2) are measured in Mongolian gerbil as a function of the independent variation of all four stimulus parameters, the frequencies (f1 and f2) and the intensities (L1 and L2) of the two stimulus tones. The main five-dimensional display chosen is a logarithmic grid of frequencies, where for each frequency pair there is a contour map of the emission amplitude as a function of the two stimulus levels. The feature which leads to the greatest complexity in the proper interpretation of emission responses is the widespread presence of “notches” in these contour maps. Notches are lines of relative minima in the emission amplitude, and are found at either: (1) constant L1, but only in regions where L1>L2; or (2) at constant L2, only where L2⩾L1. Notches are not found at any other orientations, and are associated with emission phase shifts of about 180° as the notch line is traversed. These notch characteristics are explained by phase cancellation in a simple cochlear amplifier model in which there is a change, as a function of the stimulus level alone, of relevant characteristics of the cochlear response to a single tone. Only one mechanism of emission generation is required to explain the observed patterns, i.e., there is no need to invoke different “active” and “passive” mechanisms. Unless properly accounted for, the presence of notches adversely affects all of the standard emission measurements, i.e., all methods which cover a restricted parameter set such as DPgrams, input–output or “growth” functions, and frequency ratio functions. Conversely, because the notch location appears approximately invariant in the cochlea, notches potentially make it possible to use certain emission growth functions to estimate forward and reverse middle-ear transfer functions.
Denotational semantics of a goal-directed language
Authors: Gudeman David A.
Published: October 2002

Goal-directed evaluation is a very expressive programming language paradigm that is supported in relatively few languages. It is characterized by evaluation of expressions in an attempt to meet some goal, with resumption of previous expressions on failure. This paradigm is found in SNOBL4 in its pattern-matching facilities, and in Icon as a general part of the language. This paper presents a denotational semantics of Icon and shows how Icon is in fact a combination of two distinct paradigms, goal-directed evaluation and functional application. The two paradigms are not supported separately in different contexts, but integrated fully into a single evaluation mechanism.
Wait-free synchronization
Authors: Herlihy Maurice
Published: October 2002

A
wait-free
implementation of a concurrent data object is one that guarantees that any process can complete any operation in a finite number of steps, regardless of the execution speeds of the other processes. The problem of constructing a wait-free implementation of one data object from another lies at the heart of much recent work in concurrent algorithms, concurrent data structures, and multiprocessor architectures. First, we introduce a simple and general technique, based on reduction to a concensus protocol, for proving statements of the form, “there is no wait-free implementation of X by Y.” We derive a hierarchy of objects such that no object at one level has a wait-free implementation in terms of objects at lower levels. In particular, we show that atomic read/write registers, which have been the focus of much recent attention, are at the bottom of the hierarchy: thay cannot be used to construct wait-free implementations of many simple and familiar data types. Moreover, classical synchronization primitives such as
test&set
and
fetch&add
, while more powerful than
read
and
write
, are also computationally weak, as are the standard message-passing primitives. Second, nevertheless, we show that there do exist simple universal objects from which one can construct a wait-free implementation of any sequential object.
Experience with a software-defined machine architecture
Authors: Wall David W.
Published: October 2002

We have built a system in which the compiler back end and the linker work together to present an abstract machine at a considerably higher level than the actual machine. The intermediate language translated by the back end is the target language of all high-level compilers and is also the only assembly language generally available. This lets us do intermodule register allocation, which would be harder if some of the code in the program had come from a traditional assembler, out of sight of the optimizer. We do intermodule register allocation and pipeline instruction scheduling at link time, using information gathered by the compiler back end. The mechanism for analyzing and modifying the program at link time is also useful in a wide array of instrumentation tools.
Lazy caching
Authors: Afek Yehuda , Brown Geoffrey , Merritt Michael
Published: October 2002

This paper examines cache consistency conditions for multiprocessor shared memory systems. It states and motivates a weaker condition than is normally implemented. An algorithm is presented that exploits the weaker condition to achieve greater concurrency. The algorithm is shown to satisfy the weak consistency condition. Other properties of the algorithm and possible extensions are discussed.
A compiler approach to scalable concurrent-program design
Authors: Foster Ian , Taylor Stephen
Published: October 2002

We describe a compilation system for the concurrent programming language Program Composition Notation (PCN). This notation provides a
single-assignment programming model
that permits concurrent-programming concerns such as decomposition, communication, synchronization, mapping, granularity, and load balancing to be addressed separately in a design. PCN is also extensible with
programmer-defined operators
, allowing common abstractions to be encapsulated and reused in different contexts.

The compilation system incorporates a
concurrent-transformation system
that allows abstractions to be defined through concurrent source-to-source transformations; these convert programmer-defined operators into a core notation.
Run-time techniques
allow the core notation to be compiled into a simple concurrent abstract machine which can be implemented in a portable fashion using a run-time library. The abstract machine provides a uniform treatment of single-assignment and mutable data structures, allowing data sharing between concurrent and sequential program segments and permitting integration of sequential C and Fortran code into concurrent programs.

This compilation system forms part of a program development toolkit that operates on a wide variety of networked workstations, multicomputers, and shared-memory multiprocessors. The toolkit has been used both to develop substantial applications and to teach introductory concurrent-programming classes, including a freshman course at Caltech.