High-rise City Research Articles

Analisis Kinerja Keuangan pada Usaha Mikro Kecil (Studi Kasus Usaha Roti Kacang Mpok Atik di Kota Tebing Tinggi)

This study aims to find out about the financial performance development of small micro-enterprises in a case study of peanut butter bread in a high-rise city. This research is a kind of field research. (field research). The method used is qualitative descriptive. The data collection techniques used are observations, interviews and documents. The research uses qualitative data from financial statements such as financial position reports and profit and loss reports because in this study the researchers study, analyze and draw conclusions from the financial reports of the enterprise. Based on the results of the research and analysis of the profitability ratio using the formula GPM, NPM, ROA, and ROE show that the enterprise has increased and decreased each year, the financial performance of such enterprise is assessed well in the course of the last 3 years starting from 2021-2023 If the industry average is 30% to assess the good or badness of a enterprise, then that enterprise only good in the calculation of the gross profit margin (GPM) that is above the average of the industry. In the calculation of other profitability ratios, the business of sagu flour has experienced an increase in earning profits. (in-profit). But, the average calculation results of the enterprise starting in 2021-2023 are better than in 2022.

Comparative analysis of conventional and modern high-rise hotels in Penang based on hourly simulation of cooling load performance using DesignBuilder

The study examines the energy efficiency performance of hotel façades in relation based on the annual cooling energy consumption simulation. In achieving the objective, two case studies of high-rise city hotels are selected within the locality of Penang, Malaysia. The case studies are selected based on the year of construction coupled with the architectural styles encompassing conventional and modern design of hotel facades. In the traditional design of hotel facades, passive design elements including proper selection of window and wall materials alongside window-to-wall ratio (WWR) are less significant. Comparatively, elements of passive design in the modern hotel facades are notable. In assessing the thermal performance of the hotel façade, a case study of the conventional and modern high-rise city hotels in Penang are selected to undergo hourly cooling load simulation of hotel guestroom using the DesignBuilder program in establishing the hotel’s energy efficiency performance. The findings revealed, the average annual cooling energy of the conventional and modern high-rise city hotel guestroom is 553 kWh/m2 and 538 kWh/m2 respectively. The study concludes the elements of passive design including WWR, window material selection, and external wall colour are crucial in determining energy efficient hotel operations.

Effect of wind-based climate-responsive design on city breathability of a compact high-rise city

As urban development advances, there is an increasing interest in compact cities as the most sustainable form. To suggest a pronounced connection between dense urban morphology and wind environments, this study adopts the new approach of wind-based climate-responsive design to investigate the influences of urban density, building corner modification, and wind direction on urban ventilation outcomes for the enhancement of city breathability. The airflow rates are estimated using a high-rise building array layout to optimize urban penetrability for enhancing breathability. The results of the CFD parametric study indicate that compact urban layouts with larger λp values experience good infiltration rates, ensuring wind comfort at the pedestrian level. Conversely, sparse urban forms with reduced λp values can achieve better permeation outcomes, resulting in elevated wind speeds at the middle level and near the roof of buildings, as well as higher airflow rates through the urban canyon layer. Additionally, the implementation of round corners reduces average wind speeds at the pedestrian level by 39% and increases wind speeds above the middle level of high-rise buildings by 20%, as compared to those of sharp corners. These findings offer valuable insights for high-rise building planning strategies, serving as both immediate and long-term solutions to realize the sustainable objectives of wind-based climate-responsive design in compact cities. Present research has offered the multifaceted trends of wind energy assessments on the realization of urban wind power. This paper also provides a theoretical framework that can assist urban designers in implementing the wind-based climate-responsive designs and enhancing living environments in contemporary compact cities.

Developments of Façade Design with a Special Reference to the City Hotels in Kuala Lumpur

The study examines the façade design developments of the high-rise city hotels since the 1960s post-colonial period in Malaysia. Strategically located in the tourist hub of Malaysia’s capital, three case studies of high-rise city hotels built in different architectural periods notably the 1970s Modern, the 1990s Post-Modern and the contemporary Neo-Minimalist, were meticulously selected to undertake a visual survey on the façade design elements. The high-rise hotel façade design in Kuala Lumpur as reviewed, historically began as a modest extension of shop houses and gradually metamorphosed into high-rises embodying a creative interplay of colour, material features, and climate responsive mechanisms as the architectural timeline advances. Ranging from the simplistic Modernist ideals of the International Style to the regionalist approach of the Post-Modernism and ultimately the Neo-Minimalism, each of the case studies is systematically reviewed from the spectrum of contextual history, functionality, and the aesthetics of the façade design elements. Evidently, the outcome of the study underscores the architectural developments of the city hotel façade design as expressive of the hotels’ image for contemporary trends in urban hospitality alongside a reconciliation of the capital’s tourism history.

Analysis of Hotel Façade Thermal Performance with a Special Reference to the City Hotels in George Town, Penang

The present study identifies issues pertaining energy efficiency of high-rise city hotels in Malaysia and aims to examine the thermal performance of high-rise hotels with different façade design configurations. Large hotels in the tropics of Malaysia are found to be energy intensive among commercial building categories. The present study proposes two case studies of high-rise city hotels in George Town, Penang, with different façade configurations to determine their capability to comply the Overall Thermal Transfer Value (OTTV) requirements set by the Malaysian Standards MS 1525;14 and the Green Building Index (GBI). Utilizing the OTTV formula as stipulated in the MS 1525:14, the OTTV of each case study was manually calculated using the identified façade design parameters. Comparative analysis of the results indicate that each of the cases garnered OTTV which exceeded the recommended value of 50 Wm-2. General guidelines and recommendations for improvement in the hotel façade design in the tropics are also included in the discussion.

The synergistic effect of urban heat and moisture islands in a compact high-rise city

The synergistic effect of urban heat island (UHI) and urban moisture island (UMI) aggravates the heat stress during hot summers. To investigate the mechanisms of UHI and UMI, we developed an advanced urban canopy model with more robust predictability of the urban surface heat and moisture budgets by considering dynamic building-tree-air interactions within an enhanced aerodynamic resistance network. Our results show that in a compact high-rise city, anthropogenic heat (AH) emission from building cooling systems is nonnegligible (up to 400 W/m2, including ~60% sensible heat flux and ~40% latent heat flux), which can further aggravate UHI and UMI with a 1.64 °C increase in air temperature and a 0.89 g/kg increase in air specific humidity, respectively. On the other hand, the impact of building-tree-air interactions on UHI and UMI within compact high-rise street canyons is complicated due to strong shading effect and hindered turbulent transport. In general, planting trees effectively reduces UHI (−2.90–0 °C) but leads to increased UMI (+0–1.66 g/kg), therefore an optimized tree planting strategy is needed to avoid heat stress aggravation due to high humidity. Specifically, tall trees with large and small crown areas are optimal tree types for street canyons with low and high aspect ratios, respectively. In addition to city greening, optimal building air-conditioning (AC) control in an energy-efficient mode can reduce outdoor maximum heat stress index by 1.10 °C. Furthermore, synergistic effects of optimal AC operation and optimal tree planting can effectively reduce pedestrians’ dangerous hours with heatstroke risks by 11%–35%.

Identification of microalgae cultured in Bold\u2019s Basal medium from freshwater samples, from a high-rise city

This study aimed at exploring microalgal heterogeneity from fresh water samples collected from inland water bodies in the heavily built city of Singapore. Culturable pure isolates (n = 94) were subject to an in-house microalgal DNA extraction method and LSU rDNA sequencing. Isolates were analysed for their predominance and distribution. A total of 17 different algal genera were identified (H = 2.8, EH = 0.6), of which Scenedesmus spp. and Chlorella spp. constituted 27.5% and 21.3% of isolates respectively, followed by Micractinium spp. (18.8%) and Chlamydomonas spp. (12.5%). We also report 16 new microalgal strains from this region. The data is important from an ecological and biotechnological perspective.

City-scale morphological influence on diurnal urban air temperature

Urbanization patterns affect urban thermal environments. Studies have characterized the asymmetry of daily urban air temperature based on the increase in mean temperature, decrease in amplitude, and significant phase delay in the highly compact high-rise city of Hong Kong. In this study, a simple physical-based energy balance strategy was developed to investigate urban morphological impacts on city thermal climate. This energy balance model was first evaluated by using a meso-scale model, i.e. a weather research and forecasting model coupled to the BEP-BEM urban canopy model, and then applied to investigate urban daily air temperature profiles in a high-rise compact city. The modelling results show that urban thermal storage has no direct impact on the mean urban air temperature, but does affect amplitude and phase. The results reveal that different city morphologies lead to different urban air temperature profiles. Two important parameters for engineers and urban planners are introduced: a relative convective heat transfer number λ, and a time constant, τ, which respectively describe the relationships between convective heat transfer and urban thermal storage and ventilation rate in urban areas. These two parameters modulate the mean, amplitude term, and phase term of the daily urban air temperature cycles. The results have significant implications for design of city morphologies and urban planning of climate-resilient cities. The new results from this study and the proposed simple model should facilitate the rapid development and testing of potential urban heat island mitigation strategies.

Wind weakening in a dense high-rise city due to over nearly five decades of urbanization

Decades of urbanization can lead to significant wind reduction in urban areas. At the King's Park meteorological station in the heart of the Kowloon Peninsula Hong Kong, a wind speed reduction of 0.6 m/s per decade was observed from 1968 to 1995, and -0.16 m/s per decade from 1996 to 2017. We obtained data on the changing three-dimensional urban morphology of Kowloon during the period of 1964–2010, and conducted computational fluid dynamics simulations on historical wind environment considering the prevailing winds. The wind speed and its loss were calculated as both intrinsic and comprehensive spatial averages within an elevation of 200 m. The results show that the overall mean wind speed in the studied urban areas gradually decreased due to the continuous urban development and elevation in building height. The total wind loss ratios at three representative locations have increased from less than 10% to greater than 20% during the study period. The total wind loss ratio may increase to about 40% by 2050 if the current weakening trend continues. The average wind speed at pedestrian level has significantly declined, and local acceleration of wind was only observed in some local areas. However, such accelerated airflow is only maintained around a few blocks of buildings. Our study demonstrates the impact of urbanization on the wind weakening in Hong Kong and reveals the importance and need of factoring in urban air ventilation into the design of urban morphology.

Design of high-rise dwelling houses for Ho Chi Minh City within the framework of the “smart city” concept

There are differences in the concepts of smart cities, which are reflected in many ideas and solutions. Globally one of the similarities of the goals for achieving smart cities is sustainable developmentwith the provision of best living conditions for people beingthe first priority. Ho Chi Minh City is not out of trend, taking the planning steps for the goal of becoming a smart city. It is necessary that design and construction of high-rise dwelling houses meet the criteria of “smart city” concept. This paper explores the design of high-rise dwelling houses forHo Chi Minh City with regards tothe framework of “smart city” concept. Methods used in the paper includedata collection, analytical – synthetical and modeling method.In order to proposedesign tasks and solutions of high-rise dwelling houses forHo Chi Minh Cityinthe concept “smart city”in the current period and near future, we present new approach, whichcan alsobe applied in practice for different cities in Vietnam.Moveover, it can also establishinformation resources, which areuseful in connecting and promotingfurther development for the success of a “smart city” program.

Spatially organized «vertical city» as a synthesis of tall buildings and airships

The paper explores the compact city concept based on the «spatial» urban development principles and describes the prerequisites and possible methods to move from «horizontal» planning to «vertical» urban environments. It highlights the close connection between urban space, high-rise city landscape and conveyance options and sets out the ideas for upgrading the existing architectural and urban planning principles. It also conceptualizes the use of airships to create additional spatial connections between urban structure elements and high-rise buildings. Functional changes are considered in creating both urban environment and internal space of tall buildings, and the environmental aspects of the new spatial model are brought to light. The paper delineates the prospects for making a truly «spatial» multidimensional city space.

Land use regression modelling of air pollution in high density high rise cities: A case study in Hong Kong

Land use regression (LUR) is a common method of predicting spatial variability of air pollution to estimate exposure. Nitrogen dioxide (NO2), nitric oxide (NO), fine particulate matter (PM2.5), and black carbon (BC) concentrations were measured during two sampling campaigns (April–May and November–January) in Hong Kong (a prototypical high-density high-rise city). Along with 365 potential geospatial predictor variables, these concentrations were used to build two-dimensional land use regression (LUR) models for the territory. Summary statistics for combined measurements over both campaigns were: a) NO2 (Mean=106μg/m3, SD=38.5, N=95), b) NO (M=147μg/m3, SD=88.9, N=40), c) PM2.5 (M=35μg/m3, SD=6.3, N=64), and BC (M=10.6μg/m3, SD=5.3, N=76). Final LUR models had the following statistics: a) NO2 (R2=0.46, RMSE=28μg/m3) b) NO (R2=0.50, RMSE=62μg/m3), c) PM2.5 (R2=0.59; RMSE=4μg/m3), and d) BC (R2=0.50, RMSE=4μg/m3). Traditional LUR predictors such as road length, car park density, and land use types were included in most models. The NO2 prediction surface values were highest in Kowloon and the northern region of Hong Kong Island (downtown Hong Kong). NO showed a similar pattern in the built-up region. Both PM2.5 and BC predictions exhibited a northwest-southeast gradient, with higher concentrations in the north (close to mainland China). For BC, the port was also an area of elevated predicted concentrations. The results matched with existing literature on spatial variation in concentrations of air pollutants and in relation to important emission sources in Hong Kong. The success of these models suggests LUR is appropriate in high-density, high-rise cities.

The Impact of Urbanization on Moisture Excess in Hong Kong

Urban and rural atmospheric humidity differences were analysed and studied based on the hourly average data collected in two representative meteorology stations (TKL, 15m, 22°31’43 “N, 114°09’24 “E and HKO, 32m, 22°18’07 “N, 114°10’27 “E) in Hong Kong during the period of 1994 to 2009. It was found that in winter season (December and January), the urban areas were more humid than rural areas with the highest UME value of 2.28hPa while thus phenomenon was rarely significant in the summer season which is coordinate with UHI phenomenon. In addition, an urban moisture balance model, based on urban surface hydrology and urban atmospheric moisture balance, was developed to assess the different factors on the temporal behaviour of urban moisture environment. The performance of the urban moisture balance model was also discussed. We conclude that the impact of precipitation on urban moisture environment is important for the high-compact and high-rise city with limited vegetation ratio. Moreover, urban moisture environment is affected by urban morphology, anthropogenic moisture and weather conditions.

Walking in the high-rise city: a Health Enhancement and Pedometer-determined Ambulatory (HEPA) program in Hong Kong.

Due to the lack of good infrastructure in the public estates, many older adults in urban areas are sedentary. The Health Enhancement and Pedometer-Determined Ambulatory (HEPA) program was developed to assist older adults with diabetes and/or hypertension to acquire walking exercise habits and to build social support, while engaged in regular physical activity. This study aimed to describe the HEPA program and to report changes in participants’ walking capacity and body strength after 10-week walking sessions. A pre- and postintervention design was used. Pedometers were used to measure the number of steps taken per day before and after the 10-week intervention. Upper and lower body strength, lower body flexibility, and quality of life were assessed. A total of 205 older adults completed the program and all health assessments. After the 10-week intervention, the average number of steps per day increased by 36%, from 6,591 to 8,934. Lower body strength, upper body strength, and aerobic fitness increased significantly after 10 weeks, along with improvement in the 12-item Short Form Health Survey (SF™-12) physical and mental health component summary scores. A social support network was built in the neighborhood, and the local environment was utilized to make walking possible and enjoyable.

コンパクトシティ・システムを内包する3次元都市形態

The purpose of this article is to obtain the optimum three-dimensional urban form when compact city system is formed. This article assumed hierarchical district centers and transportation system according to the stage of life needs. As a result, the optimum urban form minimizing travel costs shows that the ratio of vertical travel cost to horizontal one determines the urban area and the distance between the district centers. This result suggests that forming a concentrated high-rise city with skyscrapers depending on elevators may be less efficient than developing the urban area in the horizontal direction by utilizing the transportation.

After‐Images of the Highrise City: Visualizing Urban Change in Modern New York

After‐Images of the Highrise City: Visualizing Urban Change in Modern New York

Effects of Urban Ventilation Patterns on the Carbon Monoxide Concentration in a High-Rise Mega City

Carbon monoxide (CO) concentration data from 1999–2006, monitored at 5 different pollution stations in a high-rise mega city (Hong Kong), were collected and investigated. The spatio-temporal characteristics of urban CO concentration profiles were obtained. A new approach was put forward to examine the relationship between urban CO concentration and different wind flow patterns. Rather than relying on the meteorological data from a single weather station, usually adopted in previous studies, four weather stations on the boundary of Hong Kong territory were used in the present study so as to identify 16 different wind flow patterns, among which a typical urban heat island circulation (UHIC) can be distinguished. Higher concentrations were observed to be associated with the flow pattern of an inflow from Lau Fau Shan (LFS) station which is located in the northwest of Hong Kong. This suggests that the ability of dilution for north-to-west wind is relatively weak due to the pollutants carried from outside Hong Kong. The effectiveness of wind speed on the alleviation of urban concentration is dependent on the initial concentration of the approaching wind. The increase of wind speed of north-to-west wind from 0 m/s to 6 m/s has little effect on the reduction of urban CO concentration, especially on the non-roadside stations. By contrast, for the southerly marine wind, pollution concentration decreases sharply with an increase in the wind speed. It was also found that urban heat island circulation (UHIC) is conducive of the accumulation of pollutants, especially at night. There exists a positive correlation between CO concentration and UHI intensity. This correlation is much stronger at night compared to during the day.

Percy

Percy

Opposite-sector uplink interference in broadband FWA networks in high-rise cities

A deterministic propagation model is used to simulate broadband radio propagation at 3.5 GHz for a fixed wireless access (FWA) network in a high-rise city environment, with linear antenna polarisation. It is shown that some rooftop locations are unsuitable positions for subscriber units (SUs), due to the existence of single- or multiple-bounce reflected rays causing uplink interference. Furthermore, it is shown that it is usually possible to find an SU position just a few metres away on the same rooftop that gives much lower uplink interference.

Statistical structures of indoor traffic noise in a high-rise city

Noise measurements were conducted in seven residential flats close to the traffic in Hong Kong. Noise-level time variations and their statistics are discussed. The results of the overall noise level statistics reveal that Gaussian noise-level distribution can only be found under the free traffic-flow condition while some characteristics of gamma noise-level distributions are observed when the flow is of the interrupted type. Short-duration noise-level time variation statistics reveal a well-defined relationship between skewness and kurtosis for each traffic-flow pattern identified. Results also suggest that the Pearson type I and IV distributions are useful for describing the short-duration noise-level distributions.