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The introduction of higher density housing development within suburban areas has been favoured by state governments in Australia as a means of improving the efficiency of land use, reducing the costs associated with the delivery of government services and promoting home ownership. However it has been hypothesised that such development may have a negative impact on neighbourhood social structure, for example reducing diversity as measured by economic status and family makeup or in local housing market performance as measured by price. This paper aims to test this hypothesis.

The methodology employs a quantitative approach with principal components analysis used to capture the main social structure of the Adelaide Statistical Division. Social constructs, the product of principal components analysis, are used to measure outcomes of higher density development as measured by community or household change.

The results in this paper show that densification has had significant impact on certain neighbourhoods in the Adelaide Statistical Division notably in relation to their built form but not necessarily in neighbourhood structure or housing market performance.

The findings are significant in highlighting that increasing medium densities and improving tenure mix may not necessarily improve the opportunities for socio‐economic mix or for cultural diversity with implications for policy makers seeking to follow strategies based on the promotion of mixed communities.

This paper seeks to add new research on the outcomes of higher density development in Australia in three ways. First, social constructs, the product of principal components analysis, are used to measure outcomes of higher density development as measured by community or household change. Second, the paper investigates the development at the local level where impacts are likely to be most important. Third, the analysis identifies a before and after scenario for those suburbs where higher density development has been most significant.

Despite carbon reduction commitments, many constraints hinder the delivery of low-carbon buildings (LCBs) in high-rise high-density cities. The collaborative commitment of relevant stakeholders is vital to effectively address and mitigate these constraints. Hence, this study aims to comprehensively explore the required stakeholder collaboration attributes to address and mitigate the “common” constraints of delivering LCBs by focussing on several high-rise high-density cities.

A list of 21 “significant and common” constraints was identified through a systematic literature review followed by a questionnaire survey covering five economies (Hong Kong, Singapore, Australia, Qatar and the UAE). Nineteen influential stakeholders/stakeholder categories were identified through the literature, and their ability to influence the 21 constraints was mapped and identified through a two-round Delphi survey of 15 experienced professionals. The Delphi survey findings were analysed through social network analysis (SNA) methods to assess the stakeholder engagement and collaboration attributes.

The SNA results revealed the ability of stakeholders to influence the constraints, required collaborative stakeholder networks to address the constraints, significance of stakeholders according to the SNA centrality measures, core and periphery stakeholders and individual co-affiliation networks of core stakeholders.

While achieving the planned primary target of exploring stakeholder collaboration and their significance through SNA, this study also presents a useful sequential methodological approach for future researchers to conduct similar studies in different contexts. The findings also provide a foundation for accelerating the delivery of LCBs by strengthening stakeholder collaboration.

The objectives of this study were to demonstrate that the high-density 7-Eleven c-stores in Taiwan benefit from economies of scale in distribution and can, therefore, leverage the logistics costs; and to decide the proper locations for the future inauguration of c-stores.

The study spatially analysed the c-stores located in Tainan, Taiwan and examines the influence of spatial configuration on c-store revenue. This study developed models to quantify the revenue and logistics costs that the 7-Eleven convenience store (c-store) chain encountered when adopting a high-density expansion strategy. The revenue models’ parameters were calibrated utilizing data collected from financial statements in 7-Eleven chains’ 2015 corporate annual reports and modelling was used to quantify the influence of agglomeration forces and the distance separating c-stores on revenue.

Positive agglomeration forces increased 7-Eleven’s company-wide sales and the average daily revenue of its individual c-stores, and decreased those of competitors. The study findings demonstrate the high-density 7-Eleven c-stores in Tainan benefit from economies of scale in distribution and can, therefore, leverage their logistics costs. The spatial analysis concluded that higher-density and higher-revenue c-stores were spatially clustered.

The study extends the use of analytical revenue and spatial models to decide the proper locations for the future inauguration of c-stores.

Density optimization is the first critical step in building additively manufactured parts with high-quality and good mechanical properties. The authors developed an approach that combines simulations and experiments to identify processing parameters for high-density Ti-6Al-4V using the laser powder-bed-fusion technique. A processing diagram based on the normalized energy density concept is constructed, illustrating an optimized processing window for high- or low-density samples. Excellent mechanical properties are obtained for Ti-6Al-4V samples built from the optimized window.

The authors use simple, but approximate, simulations and selective experiments to design parameters for a limited set of single track experiments. The resulting melt-pool characteristics are then used to identify processing parameters for high-density pillars. A processing diagram is built and excellent mechanical properties are achieved in samples built from this window.

The authors find that the laser linear input energy has a much stronger effect on the melt-pool depth than the melt-pool width. A processing diagram based on normalized energy density and normalized hatch spacing was constructed, qualitatively indicating that high-density samples are produced in a region when 1 < E* < 2. The onset of void formation and low-density samples occur as E* moves beyond a value of 2. The as-built SLM Ti-6Al-4V shows excellent mechanical performance.

A combined approach of computer simulations and selected experiments is applied to optimize the density of Ti-6Al-4V, via laser powder-bed-fusion (L-PBF) technique. A series of high-density samples are achieved. Some special issues are identified for L-PBF processes of Ti-6Al-4V, including the powder particle sticking and part swelling issues. A processing diagram is constructed for Ti-6Al-4V, based on the normalized energy density and normalized hatch spacing concept. The diagram illustrates windows with high- and low-density samples. Good mechanical properties are achieved during tensile tests of near fully dense Ti-6Al-4V samples. These good properties are attributed to the success of density optimization processes.

The paper discusses the position of low rise, high density housing in Hungary on a theoretical level, from the conceptional point of view. The purpose is that the dissemination and popularization of the housing type would be beneficial to the society. Before and after World War Two different nature of this housing type was present in the country, but after the regime change in 1989 the continuity has been lost.

This paper aims to support the above assumptions - discussing the benefits of the installaton type in the light of global and local issues, and search of the housing type’s local positions. The actuality of housing issue is relevant because of the planning of 2014-2020 housing program, the fall of yearly built houses, the imbalance of housing allocation and the urgent questions of global problems.

The paper’s method is threefold (1) discusses the potential of the housing type in correlation with the three pillars of sustainability, (2) analyses past examples from three different periods of the past century and (3) searches its position according to actual social changes and suggests strategic objectives for the future use of low rise, high density housing in the country.

The urban population in Indian cities is increasing at an alarming speed. Accommodating such a huge population while sustaining the environment is a challenge in urban areas. Compact urban forms with high-density planning is claimed to be a sustainable solution in such situations. Thus, this approach needs to be tested for Indian urban areas.

This paper formulates a neighbourhood sustainability assessment (NSA) framework for monitoring, assessing and managing the population density of urban neighbourhoods. The paper identifies context-specific built density indicators at the neighbourhood scale. It assesses the indicators in neighbourhoods with varying population density by physical and perceived measures. This helps in verifying the feasibility of density by physical density assessment and verifies the acceptability of density by perceived density assessment.

When tested in the Indian context, the framework shows that although high-density neighbourhoods are sustainable, certain indicators may endorse differing densities. The result displays that high-density planning is sustainable compared to low- and medium-density neighbourhoods in the selected cities.

The study demonstrates the application of formulated assessment system in three central Indian cities with useful results. Similar studies can be conducted to identify the gaps for improving sustainability and achieve a livable density pattern.

Although sustainable development goals are part of new planning policies, there exist very few assessment systems to determine the sustainability of neighbourhoods, especially for density. The methodology will assist in developing sustainability assessment frameworks and encourage the practice of sustainability assessment in developing countries like India.

This paper developed a new method of making floor from poplar using glued technology and densification technology. This paper aimed to use fast-grown poplar wood to produce floor to expand material supply range of floor in order to solve problem of material supply shortage for floor industry.

Densification technology and gluing technology were used to obtain high-density surface materials of floor under high pressure, meanwhile in order to reduce loss of poplar wood caused by compressing, high-density surface materials floor and substrate are glued and pressed under low pressure.

The method of compressing poplar wood under high pressure can improve poplar's physical and mechanical properties. Adopting densification technology and gluing technology can produce the poplar laminated composite floor which meets the requirements of Chinese standard GB/T 18103.

This method of producing floor by compression densification technology would cause wood loss from reduction in thickness because poplar was pressed under high pressure.

This method of making floor from poplar wood concerned in this study allows the floor making industry to eliminate its dependence on precious wood resource, expand supply range of floor material, and then solve problem of wood supply shortage of floor industry.

This study may help solve the difficult problem that poplar cannot directly be used to produce floor because of its softness, low density and low strength. Through densification technology, great improvement in strength and hardness of poplar had been made.

The primary purpose of this study is to identify whether there is a price premium and consumers’ preferences for higher housing density, and whether there is a relationship between housing densities and sales prices. The second purpose was to identify if there is a non-linear relationship between housing density and prices even though housing density is directly associated with housing prices.

This paper applies hedonic modeling techniques to measure the value of development density of apartments in the metropolitan area of Seoul, South Korea. The regression of the sale price is a function of different types of variables such as density, market, location and other control variables.

For the first question, this paper concludes that the higher densities cause housing prices to decrease in Seoul. The summary of the results presents that housing density, floor area ratio (FAR), building coverage ratio and floor level are all important components affecting housing prices. Generally, consumers tend to buy housing with central heating systems, more parking spaces, smaller portion of rental housing within an apartment and buildings that have more of a mixed-use function. Consumers are also found to pay higher premiums for housing in areas with high population growth and less housing supply. It is conclusive that people are inclined to live in populated areas but do not want more density. For the second question, the results show that generally FAR has quadratic effects, but most housing density variables tend to have a non-linear relationship depending on the different quantile groups.

There is a knowledge gap in the area of estimating development density of apartments. Generally, studies investigating property value impacts of multifamily housing focus on external effects of the multifamily housing on home values to examine whether high density development could result in a decrease in nearby property values. These studies found that there are some positive effects. A study found that high-density housing increases property values of existing single-family homes (Joint Center for Housing Studies, 2011). More specifically, developments that are of a high design quality and superior landscaping increase values of single-family homes as well. Also, those residents who live in these high-density apartments can be good potential buyers for the existing single-family homes. The greater the number of buyers, the greater the housing market becomes. Similarly, according to a report by the Joint Center for Housing Studies (2011) at Harvard University, the presence of multifamily residents correlates with higher home values in “working communities”. Indeed, density can be an important factor determining value of apartments because of its unique characteristics. However, no empirical evidence has been provided in the literature with regard to the value of the development density. This study contributes toward improving this knowledge gap.

The High Density Packaging Users Group Consortium has conducted a study of process development and solder‐joint reliability of high‐density packages on printed circuit boards (PCB) using a low‐melting temperature lead‐free solder. The purpose of this paper is to investigate the reliability tests (e.g. temperature cycling and shock and vibration) and failure analysis (FA) of high‐density packages on PCB with the low‐melting temperature lead‐free solder (Sn‐57 wt%Bi‐1 wt%Ag).

The design for reliability, materials, and assembly process aspects of the project have been discussed in “Design, materials, and assembly process of high‐density packages with a low‐temperature lead‐free solder (SnBiAg)” also published in this journal issue. In this study, reliability tests (e.g. temperature cycling and shock and vibration) and FA of high‐density packages on PCB with the low‐melting temperature lead‐free solder (Sn‐57 wt%Bi‐1 wt%Ag) are investigated.

Lead‐free solder‐joint reliability of high‐density packages, such as the PBGA388, PBGA256, PBGA208, PBGA196, PBGA172, PQFP80, and TSSOP56 were determined by temperature cycling, shock, and vibration tests. Temperature cycling test data for over 8,100 cycles between 0 and 100°C in a 44 min. cycle were statistically analyzed. Shock and vibration test data based on the HP Standard Class Bi‐II Products SPEC have also been reported.

Currently there is a lack of experimental and simulation data and field experience in respect of one of the critical issues for industry – that of solder joint reliability in lead‐free soldering. The paper contains some important research results and recommendations.

PLANET OF SLUMS

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